JP4419764B2 - Coating device and coating method - Google Patents

Description

  The present invention relates to a coating apparatus and a coating method for applying a paste or dropping a liquid crystal on a substrate in a flat panel manufacturing process.

  As a conventional technique, as described in Patent Document 1, a glass substrate is placed on a table that can move in the XYθ direction, and is opposed to the nozzle discharge port with respect to the main surface of the glass substrate. The paste pattern having a desired shape is applied to the substrate by changing the relative positional relationship between the substrate and the nozzle while discharging the paste filled in the paste storage cylinder onto the substrate from the discharge port. There is a configuration one.

JP-A-7-275770

  In the above-mentioned prior art, in the field of flat panels such as LCD, the size of the glass substrate has been increased, the coating range of the coating head has been expanded, and the portal frame that supports the coating head is thus long and large. Because the temperature of the equipment changes during transportation of the equipment, into the clean room, and room temperature fluctuations in the clean room, thermal stress due to thermal elongation occurs in the gate frame, and deformation and paste of the gate frame It is difficult to apply and draw a pattern in a desired shape.

  As mentioned above, as the glass substrate size increases, the portal frame that supports the coating head also becomes longer and larger, and the temperature state of the device, such as during transportation of the device, loading into the clean room, and room temperature fluctuations in the clean room, etc. Changes. For this reason, thermal stress due to thermal elongation is generated in the portal frame, and it becomes difficult to apply and draw the paste pattern in a desired shape and position.

  Accordingly, an object of the present invention is to realize an apparatus for preventing the deformation of the portal frame and the deterioration of the application position accuracy due to thermal elongation and making the paste pattern shape a desired shape.

  In the present invention, since the thermal expansion in the longitudinal direction of the portal frame that supports a plurality of coating head portions including the nozzles by linear motion guidance is supported by the linear motion guide, the generation of thermal stress generated in the frame is prevented. It can be configured to prevent, and the thermal elongation length of the frame in the installation environment of the apparatus can be measured by a reference device, the nozzle can be positioned at a desired position on the substrate, and a desired paste pattern can be applied and drawn. Thus, a paste coater was used so that correction control was possible.

  As described above, according to the present invention, when a four-paste paste pattern is applied and drawn on the main surface of the substrate, thermal deformation of the portal frame due to thermal elongation due to the installation environment of the apparatus is prevented, and the paste It is possible to provide a paste applicator that reduces a pattern application position error and obtains a desired pattern shape.

  The present invention is provided with a frame (horizontal beam) of a portal frame portion provided with a coating head X-axis moving mechanism that linearly guides a plurality of coating head portions including nozzles. Along with the increase in size of the apparatus, the frame is stretched due to the ambient temperature environment and the like, the frame is bent, an error occurs in the application position, and there is a problem that accurate paste application and liquid crystal dripping cannot be performed. Therefore, in the present invention, in order to prevent deformation due to thermal elongation (extension in the X-axis direction) in the longitudinal direction of the frame, one side of the frame (lateral beam) is fixedly supported and the other side is movable in the X-axis direction ( It is configured to be supported by a linear motion guide that can be fixed in the Y-axis direction. Thereby, it was comprised so that generation | occurrence | production of the thermal stress which arises in a flame | frame could be prevented. Also, a method for measuring the thermal elongation length of the frame in the installation environment of the apparatus with a reference device, positioning the nozzle at a desired position on the substrate, and performing correction control so that a desired paste pattern can be applied and drawn. Adopted. This will be described in detail in the following examples.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, an apparatus that draws a paste pattern (sealing material pattern) on the substrate surface will be described as an example. Similarly, it can be applied to a dropping apparatus that drops liquid crystal on a substrate with a portal frame structure. Yes.

FIG. 1 is a perspective view showing an embodiment of a paste applicator according to the present invention. In addition, in order to avoid complication, the numbers of the respective parts of the plurality of coating heads installed facing each other will be described by adding suffixes a to f to the numbers of the respective parts in the following description.
One end of each frame (lateral beam) 2a, 2b is fixed to the support leg 31a or the linear motor 4b so that it cannot move in the X-axis direction. Further, the other ends of the horizontal beams 2a and 2b are supported by the thermal elongation guides 25a and 25b so as to be movable in the X-axis direction. This thermal elongation guide has, for example, a rail provided in the X direction on one side and a slide bearing or a rolling bearing structure so as to move on the rail. Note that the structure is not limited to the above as long as the structure can freely move in the X-axis direction.

  In FIG. 1, on one side of the gantry 1, a cross beam 2a provided with a moving mechanism (linear rail) for moving a plurality of coating heads each provided with a linear motor in the X-axis direction is provided on the support member 31a. It is fixed and a heat elongation guide 25a is provided on the other end side. A transverse beam 2b provided with a moving mechanism (linear rail) for moving each of a plurality of other application heads each provided with a linear motor in the X-axis direction is provided at a position facing the transverse beam 2a. The horizontal beam 2b is provided with linear rails as mechanisms 3a and 3b for adjusting the distance between the coating heads fixed to the base 1 so that the horizontal beam 2b can move in the Y-axis direction. , 4b are provided. In addition, one end side of the horizontal beam 2b is fixedly supported by the linear motor 4b so as not to move in the X-axis direction, and the other end side is supported via a thermal elongation guide guide 25b so as to be movable in the X-axis direction. . A Y-axis moving table 6 that supports the substrate 7 and moves it in the Y-axis direction is provided on the rack 1 that faces the horizontal beams 2a and 2b. The Y-axis moving table 6 is provided with a substrate holding mechanism 5 thereon.

  The transverse beams 2a and 2b of the plurality of coating heads are provided with linear motion guides and a linear servo motor is provided on the coating head side, and each coating head is controlled to move in the X-axis direction. The plurality of coating head units are provided with a Z-axis moving table support bracket in which a linear servo motor for X-axis direction movement for supporting the plurality of coating heads is provided on the back side and Z-axis servo motors 10a to 10f are provided on the front side. 8a-8f are provided. Z-axis moving tables 9a to 9f for moving the coating portion up and down by the Z-axis servo motors 10a to 10f are provided. On this Z-axis moving table, a paste storage tube (syringe) 13a, a nozzle support 14a provided with nozzles, a distance meter 16a, and a lens barrel having an illuminable light source and an image recognition camera 15a are attached.

  The lens barrel and the image recognition camera 15a having a light source capable of illumination are used for parallel adjustment and spacing adjustment of each coating nozzle, as well as for substrate alignment and paste pattern shape recognition. It is provided so as to oppose.

  Inside the gantry 1 is provided a main controller 17a for controlling linear motors 4am, 4bm, 8am to 8fm for driving each mechanism and a servomotor 6m for moving the table. The main controller 17a is connected to the sub controller 17b via a cable 17e. The sub-control unit 17b controls the servo motors 10a to 10f that drive the Z-axis movement table. A monitor 17f, a keyboard 17g, a hard disk 17c as an external storage device, and a floppy disk 17d are connected to the main controller 17a. The data of various processes in the main control unit 17a is input from the keyboard 17g, and the amount of frame expansion is calculated from the images captured by the image recognition cameras 15a to 15f and the position calculation by the image processing performed in the main control unit 17a. The processing status is displayed on the monitor 17f. Data input from the keyboard 17g is stored and stored in a storage medium such as a hard disk 17c or a floppy disk 17d which is an external storage device.

  FIG. 2 is an enlarged perspective view showing the paste storage cylinder 13a and the distance meter 16a in FIG. From the paste storage cylinder to the tip of the nozzle is supported by a nozzle support 14a. In FIG. 2, parts corresponding to those in FIG.

  The distance meter 16a measures the distance from the tip of the nozzle to the surface (upper surface) of the substrate 7 made of glass by non-contact triangulation. That is, a light emitting element is provided in the casing of the distance meter 16, and the laser light L emitted from the light emitting element is reflected at a measurement point on the substrate 7 and received by a light receiving element also provided in the casing. Further, the laser beam measurement point S on the substrate 7 and the position directly below the nozzle 13an are shifted by a slight distance on the substrate 7. However, with this slight distance shift, the surface irregularities of the substrate 7 are uneven. Therefore, there is almost no difference between the measurement result of the distance meter 16a and the distance from the tip of the nozzle 13an to the surface (upper surface) of the substrate 7. Therefore, by controlling based on the measurement result of the distance meter 16, the distance (interval) from the tip of the nozzle 13an to the surface (upper surface) of the substrate 7 in accordance with the unevenness (undulation) of the surface of the substrate 7 is set. Can be kept constant.

  In this way, the distance (interval) from the tip of the nozzle 13a to the surface (upper surface) of the substrate 7 is kept constant, and the amount of paste discharged from the nozzle 13an per unit time is kept constant. Accordingly, the paste pattern applied and drawn on the substrate 7 has a uniform width and thickness.

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

  FIG. 3 is a block diagram showing the configuration of the main control unit in FIG. 1, wherein 17aa is a microcomputer, 17ab is a motor controller, 17ac is a data communication bus, 17ad is an external interface, 17ae is an image recognition device, and 17af is each X-axis linear motor driver for application head movement, 17ag and 17ah for Y-axis linear motor driver for adjusting the distance between application heads, 17ai for table Y-axis motor driver, and 17aj for application head Y-axis adjustment movement motor It is a driver and the same code | symbol is attached | subjected to the part corresponding to above-mentioned drawing.

  In the figure, a main control unit 17a performs image processing for processing video signals obtained by a microcomputer 17aa, a motor controller 17ab, axis drivers 17f to 17j such as an X axis, a Y axis, and a table Y axis, and an image recognition camera 15a. It incorporates an external interface 17ad that performs signal transmission between the device 17ae and the sub controller 17b, and controls the regulators 22a to 22f, 23a to 23f, and valve units 24a to 24f.

  Although not shown in the microcomputer 17aa, the main calculation unit, a ROM storing a processing program for performing coating and drawing, which will be described later, processing results in the main calculation unit, and input data from the external interface 17ad and the motor controller 17ab are received. A RAM for storing data, an input / output unit for exchanging data with the external interface 17ad and the motor controller 17ab are provided.

  Each motor 8 am-8fm, 4am, 4bm, 6m has a built-in linear scale that detects the position and an encoder that detects the amount of rotation. The detection results are displayed on each axis such as the X axis, Y axis, and table Y axis. Position control is performed by returning to the drivers 17f to 17j.

  4 is a block diagram showing the configuration of the sub-control unit 17b in FIG. 1, in which 17ba is a microcomputer, 17bb is a motor controller, 17bc is a data communication bus, 17bd is an external interface, and 17be is for a Z-axis motor. It is a driver and the same code | symbol is attached | subjected to the part corresponding to above-mentioned drawing.

  In the figure, a sub-control unit 17b is an external interface 17bd for inputting height data obtained by a microcomputer 17ba, a motor controller 17bb, a Z-axis driver 17be, and distance meters 16a to 16f and transmitting signals to the main control unit 17a. Built in. Although not shown in the microcomputer 17ba, a ROM that stores a processing program for controlling the height of the nozzle 13an at the time of the main calculation unit and coating drawing, which will be described later, a processing result in the main calculation unit, an external interface 17bd, It includes a RAM that stores input data from the motor controller 17bb, an input / output unit that exchanges data with the external interface 17bd and the motor controller 17bb, and the like. The Z-axis motors 10a to 10f have a built-in encoder for detecting the amount of rotation, and the detection result is returned to the Z-axis driver 17be for position control.

  The motors 8am to 8fm, 4am, 4bm, 6m, 10a to 10f are input from the keyboard 17g and stored in the RAM of the microcomputer 17aa under the control of the main control unit 17a and the sub control unit 17b. By moving and rotating based on the data, the substrate 7 held by the substrate holding mechanism 5 (FIG. 1) moves an arbitrary distance in the Y-axis direction, and the Z-axis movement moves the nozzle part up and down. The supported nozzles 13an (FIG. 2) to 13fn are moved through the tables 9a to 9f by the X movement mechanisms 2a and 2b of the coating head by an arbitrary distance in the X axis direction. During the movement, the paste storage cylinder 13a is moved. The atmospheric pressure set to ˜13f is continuously applied, and the paste is ejected from the ejection port at the tip of the nozzles 13an to 13fn, and a desired paste pattern is applied to the substrate 7 It is.

  While the nozzles 13an to 13fn are moving horizontally in the X-axis direction, the distance meters 16a to 16f measure the distance between the nozzles 13an to 13fn and the substrate 7, and the nozzles 13an to 13fn are always maintained at a constant distance. It is controlled by the vertical movement of the Z-axis movement tables 9a to 9f.

Next, the operation of the apparatus in this embodiment will be described with reference to FIG.
In FIG. 5, when the power is turned on (step 100), first, initial setting of the coating machine is executed (step 200). In this initial setting step, in FIG. 1, the motor for moving each axis and the Z-axis moving table 9 are driven to move the substrate holding mechanism 5 in the Y direction so as to be positioned at a predetermined reference position. 13an (FIG. 2) is set to a predetermined origin position so that the paste discharge port becomes a position where paste application starts (ie, paste application start point), and further, paste pattern data and substrate position data, The paste discharge end position data is set.

  The data is input from the keyboard 17g (FIG. 1), and the input data is stored in the RAM built in the microcomputer 17aa (FIG. 3) as described above.

  When this initial setting step (step 200) is completed, the final collection process of thermal expansion correction data is executed. In the present invention, the amount of elongation of the frame is measured using a reference device. The reference device includes a camera provided in each of the coating heads described above, a reference substrate mounted on the table side, or a table end side. And the like, a camera position, and a processing unit in the Sho control device that obtains the frame extension amount from the position of the mark or scale obtained by the camera.

  Here, the reference substrate shown in FIG. 6 is mounted on the table for calibration by a manual operation or the like.

  On the reference substrate, marks for position calibration are formed on the thin film with a predetermined positional accuracy at a pitch set in the XY axis direction. The mark is imaged by a camera mounted on the coating head, the thermal elongation length is calculated from the position coordinates, and used as coating position correction data in the paste pattern coating drawing process in step 600.

  In addition, as shown in FIG. 6, by forming a position calibration mark on the application surface of the actual substrate to which the paste pattern is applied, the thermal elongation correction data collection process in step 300 is performed after the substrate mounting process in step 400. You may implement.

  Alternatively, a member made of glass or the like that is less stretched by heat and provided with a reference scale may be provided at the end of the table, and the scale of the reference member may be measured to measure the frame elongation.

  Next, the substrate 7 is mounted and held on the substrate suction mechanism 5 (FIG. 1) (step 400).

  Subsequently, a substrate preliminary positioning process (step 500) is performed. In this process, the positioning mark of the substrate 7 mounted on the substrate holding mechanism 5 is photographed using a camera set from among the image recognition cameras 15a to 15f, and the center of gravity position of the positioning mark is obtained by image processing. Then, the inclination of the substrate 7 in the θ direction is detected, the servo motors 30am to 30fm (FIG. 3) are driven in accordance with this, the application head is moved in the Y-axis direction, and the inclination in the θ direction is corrected. Thus, the substrate preliminary positioning process (step 500) is completed.

  Next, paste pattern drawing processing (step 600) is performed.

  In this process, the discharge ports of the nozzles 13an to 13fn are moved to the application start position of the substrate 7, and the nozzle positions are compared and adjusted. In the comparison / adjustment movement here, the control proceeds by using the thermal elongation correction data obtained in the previous step 300.

  Next, the servo motors 10a to 10f and the Z-axis moving tables 9a to 9f are operated to set the heights of the nozzles 13an to 13fn to the paste pattern drawing height.

  The nozzles 13an to 13fn are lowered by the initial moving distance based on the initial moving distance data of the nozzle. In the subsequent operation, the surface height of the substrate 7 is measured by the distance meters 16a to 16f, whether or not the tips of the nozzles 13an to 13fn are set to the height at which the paste pattern is drawn is set, and the drawing height can be set. If not, the nozzles 13an to 13fn are lowered by a minute distance, the above-mentioned substrate 7 surface measurement and the nozzles 13an to 13fn are repeatedly lowered, and the tips of the nozzles 13an to 13fn are set to the paste pattern coating drawing height. To do.

  When the above processing is completed, the linear motor motors 6m and 8am to 8fm are driven based on the paste pattern data stored in the RAM of the microcomputer 17aa and the inclination in the θ direction, whereby the nozzles 13an to 13an are driven. With the 13 fn paste discharge port facing the substrate 7, the nozzles 13 an to 13 fn and the substrate 7 move in the X and Y directions according to the paste pattern data, respectively, and the pressure set in the paste storage cylinders 13 a to 13 f Is applied to start discharging the paste from the paste discharge ports of the nozzles 13an to 13fn. Thereby, application of the paste pattern to the substrate 7 is started.

  At the same time, as described above, the microcomputer 17ba of the sub-control unit 17b inputs measured data of the distance between the paste discharge ports of the nozzles 13an to 13fn and the surface of the substrate 7 from the distance meters 16a to 16f. Then, the swell of the surface of the substrate 7 is measured, and the servo motors 10a to 10f are driven according to the measured values, so that the set heights of the nozzles 13an to 13fn from the surface of the substrate 7 are kept constant. . Thereby, a paste pattern can be apply | coated with a desired application amount.

  As described above, the drawing of the paste pattern proceeds. However, if the paste discharge port of the nozzles 13an to 13fn is the end of the drawing pattern determined by the paste pattern data on the substrate 7, it is not this end. Then, the process returns to the measurement process of the surface waviness of the substrate again, and the above-described coating drawing is repeated until the paste pattern formation reaches the end of the drawing pattern.

  When the drawing pattern end is reached, the servo motor 10 is driven to raise the nozzle 13a, and the paste pattern drawing step (step 600) is completed.

  Next, the process proceeds to a substrate discharge process (step 700). In FIG. 1, 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 800). 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 400). When such a series of processes for the substrate is completed, all the operations are completed (step 900).

  As described above, in the present invention, the frame is restrained from being bent due to the thermal stress generated in the frame by freely extending to one side without suppressing the thermal elongation generated with the temperature change of the surrounding environment. In addition, high-precision coating and dropping are realized by performing coating and dropping while correcting changes in the frame length that change due to thermal elongation.

It is a perspective view which shows one Embodiment of the paste coating device by this invention. It is a perspective view which shows the structure of the coating head in embodiment shown in FIG. FIG. 2 is a block diagram showing a main control system in the embodiment shown in FIG. 1. It is a block diagram which shows the sub control system | strain in embodiment shown in FIG. 2 is a flowchart showing the overall operation of the embodiment shown in FIG. It is a figure explaining the application | coating state of a paste pattern.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Stand, 2a, 2b ... Coating head X-axis moving mechanism, 3a, 3b ... Coating head space | interval adjustment mechanism, 4a, 4b ... Space adjustment linear motor, 5 ... Substrate holding mechanism, 6 ... Table Y-axis direction moving mechanism, 7 ... Substrate, 8a-8f ... Z-axis moving table support bracket, 9a-9f ... Z-axis moving table, 10a-10f ... Z-axis servo motor, 13a-13f ... Paste storage cylinder (syringe), 13an-13fn ... Application nozzle , 15a to 15f: a lens barrel and an image recognition camera having a light source capable of illumination, 16a to 16f ... a distance meter, 17a ... a main control unit, 18b ... a sub control unit, 17f ... a monitor, 17g ... a keyboard, 17c, 17d ... external storage device (hard disk, floppy disk), 17e ... communication cable, 22v ... negative pressure source, 22a-22f ... negative pressure regulator, 23p Pressure source, 23 a to 23 f ... positive pressure regulator, 24a through 24f ... valve unit, 25a, 25b ... thermal extension guides.

Claims (3)

A gate frame having a frame with a plurality of coating heads, a nozzle provided in the coating head, and a substrate placed on the table so as to face the discharge port of the nozzle, and filled in a storage cylinder In a coating apparatus that applies a coating liquid to a desired shape or a desired position on the substrate by discharging a coating liquid onto the substrate from the discharge port and changing a relative positional relationship between the substrate and the nozzle. ,
The frame has a structure in which one end side is fixed and the other end is supported by a linear guide so as to be movable in the longitudinal direction of the frame .
In addition, the coating apparatus is provided with a reference device, measures the amount of elongation of the frame measured by the reference device, and corrects the position of the coating head based on the measurement result . The coating apparatus according to claim 1,
The reference device includes a reference substrate provided with a plurality of alignment marks, a camera for observing the alignment marks provided on the coating head side, and a processing unit that calculates an extension amount of the frame from a captured image of the camera. coating apparatus for a child and a feature consisting of a. From a plurality of coating heads provided on the frame so as to be movable in the longitudinal direction of the frame and nozzles provided on the plurality of coating heads, a coating liquid is dropped on a substrate surface provided facing the nozzles or In the application method to apply,
The frame has one end fixed, and the other end supported by a linear guide so as to be movable in the longitudinal direction of the frame.
In dropping or coating the coating liquid, setting the coating conditions, setting each nozzle position as the origin,
Measuring the amount of thermal elongation of the frame;
Correcting the origin position of each coating head according to the measured amount of thermal elongation;
Coating method characterized in that from the corrected home position and a step of executing the application.

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