JP2949562B2 - Method of correcting coating position in paste coating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paste applying method in a silver paste applying apparatus used in, for example, a manufacturing process of a liquid crystal display.

[0002]

2. Description of the Related Art As a liquid crystal display device, a thin film transistor (TFT) is used.
m transistor) using an array substrate or the like is known. For example, in a TFT array substrate, a transfer electrode for energizing each of the electrodes is formed by applying a silver paste to an application target (transfer pad) formed on the TFT array substrate.

When applying a silver paste, a TFT array substrate to be processed is mechanically positioned and held.
A positioning mark formed at a predetermined position on the substrate is photographed by a monitor camera, and the photographed position is compared with a predetermined reference position to determine a positional deviation amount (displacement amount) of the TFT array substrate, and the displacement amount is reduced. As described above, the coordinate data of the control mechanism that controls the relative position between the application mechanism and the application target portion is generally corrected.

The positioning marks are provided on the TFT array substrate because of the cutting accuracy of the substrate, the printing position accuracy of the pattern with respect to the outer shape of the substrate, and the repetition accuracy of the positioning mechanism. This is because the target location may vary. However, since the positioning mark and the application target portion are made on the same screen, there is no variation in their positional relationship. Therefore, conventionally, if the displacement amount of the positioning mark is determined after positioning based on the outer shape reference, it is possible to determine from the displacement amount how much the pattern of the application target portion on the substrate is relatively deviated from the reference position. This is to correct the coordinate data.

As a technique for applying such a silver paste, as disclosed in Japanese Patent Application Laid-Open No. 2-137339, a technique for obtaining the displacement of a substrate from the result of imaging a positioning mark with two sets of monitor cameras, or As disclosed in Japanese Patent Application Laid-Open No. 1-122127, a technique is known in which a positioning camera is imaged by a monitor camera mounted on a paste application head, and a displacement amount of a substrate is similarly obtained. In these techniques, an illuminating device for illuminating the positioning mark with the monitor camera is provided, and therefore, the device configuration is somewhat complicated.

[0006]

As described above, the conventional coating position correction method shifts the coordinate data of the control mechanism based on the displacement amount of the positioning mark. Is uniformly corrected. However, in the conventional correction method, for example, if there is a rotational deviation, the correction error may have a greater effect as the distance from the coordinate origin increases, and it may not be possible to correct all application positions in the correct direction. Further, it cannot be confirmed whether the corrected individual application positions are really predetermined positions. Therefore, there is a case where the silver paste cannot be correctly applied to all the application target portions, and there is a problem that the yield of the TFT array substrate cannot be improved.

An object of the present invention is to provide a correction method for accurately applying paste to all of a plurality of application target portions in view of the above problems.

[0008]

A method for correcting a coating position in a paste coating apparatus according to the present invention for solving the above-mentioned problems is described below.
Positioning means for positioning the substrate to be processed at a predetermined position, applying mechanism for applying a paste to each of the plurality of coating target portion on the substrate that is positioned, the coating
Attached monitor camera with mechanisms, and corresponding said monitor camera at the paste applying apparatus provided with a control mechanism for controlling the position of the coating mechanism to an application target portion on the substrate together with the coating mechanism Move to dispensing position
It is first to measure the center position by imaging the portion
And a second step of detecting a displacement amount between the measured center position and a predetermined reference position, and a third step of correcting the position of the application mechanism so that the detected displacement amount is reduced. Are executed at least in this order . In addition, after the correction of the application position,
Determine whether the displacement from the reference position is within the correctable range
Performed based on the calculation result based on the imaging, and if it is out of range
For example, the first and second steps may be executed again.

[0009]

[0010]

According to the present invention captures a monitor camera associated one of the coating target portion of the substrate that is positioned in the coating mechanism,
The amount of displacement between each application target portion and a predetermined reference position is determined by, for example, image processing, and the position of the coating mechanism is corrected so that the determined amount of displacement is reduced. In this way, unlike the conventional case, the application positions corresponding to all the application target locations are uniformly corrected, but the application position is corrected for each application target location. Correction can be performed correctly, but it is not impossible to correct other application positions .

After the paste application, the same monitor camera captures an image of the paste application shape at the application target location, and compares the imaged application shape with the reference shape to determine the paste application status at the application target location. Can be grasped.

[0012]

Next, an embodiment of the present invention will be described in detail with reference to the drawings, taking as an example a case where a TFT array substrate is manufactured using a silver paste. FIG. 1 is an external perspective view of a paste application device according to one embodiment of the present invention. This paste application device includes a positioning unit 1, a conveyor 2, a discharge conveyor 3, a positioning mechanism 4, an orthogonal robot 5, a coating mechanism 6, a monitor camera 7, a visual device 8, and the like.

The positioning section 1 and the positioning mechanism 4 are for mechanically positioning and fixing the TFT array substrate conveyed from the previous process for applying silver paste. The array substrate is transported in the direction of the arrow. The discharge conveyor 3 discharges the TFT array substrate after the silver paste has been applied to the next step.

The orthogonal robot 5 controls the movement of the coating mechanism 6 and the monitor camera 7 in the horizontal direction (X and Y axis directions) and the vertical direction (Z axis direction) by control from a control mechanism (not shown). For example, 3
What is marketed as an axis orthogonal coordinate type robot is used. The application mechanism 6 will be described later in detail with reference to FIG.

The monitor camera 7 is, for example, a CCD (solid-state image sensor) or the like.
The image of the application target portion on the FT array substrate and the application shape after the silver paste is applied are image-recognized, and the signals are transmitted to the visual device 8. Based on the transmitted signal, the visual device 8 calculates and calculates a predetermined point, for example, a center position, of the application target location, and after applying the silver paste, applies the image-recognized application shape and a predetermined reference shape. Compare. The comparison of the shapes is performed by, for example, an area comparison. If the area of the application shape is smaller than the reference area, an application process is performed by the application mechanism 6 as described later.

As shown in FIG. 2, the coating mechanism 6 includes a coating mechanism base 21 mounted on the orthogonal robot 5 and a syringe base 13 mounted on the coating mechanism base 21 via the slide rail 12. . As a result, the syringe base 13 can move in the vertical direction with respect to the coating mechanism base 21. A syringe 16 containing silver paste is held by the syringe base 13 by the syringe holder 14. An application nozzle 17 is mounted on the syringe 16. A tension spring 15 is attached between the application mechanism base 21 and the syringe base 13. Due to the action of the tension spring 15, a downward load is always applied to the syringe base 13. The contact detection sensor 19 is held on the application mechanism base 21 by a sensor holder 20. Contact sensor 1
The tip of 9 is in contact with the syringe base 13, whereby the displacement of the syringe base 13 can be detected. That is, the application nozzle 17 is moved to the TFT array substrate 11
When the contact is made, the syringe base 13 slides and the contact detection sensor 19 operates.

Next, the operation of this embodiment will be described with reference to FIGS. FIG. 3 shows a state where the TFT array substrate 11 is positioned at a predetermined position on the positioning unit 1 by the positioning mechanism 4. In other words, the TFT array substrate 1
1 is carried in (step (hereinafter abbreviated as S) 1) and guided to a predetermined portion of the positioning section 1 to perform positioning of the outer mold (S2). Next, the monitor camera 7 attached to the orthogonal robot 5 together with the coating mechanism 6 is moved to a coating position corresponding to one of the coating target positions on the TFT array substrate 11 thus positioned, and the position is imaged. Measurement is performed (S3). Then, based on this imaging, the visual device 8 calculates the center position of the application target portion by calculation.

In this case, it is determined whether or not the amount of displacement of the application target portion from the reference position is within a correctable range (S4).
If it is out of the range, the processes from S2 to S4 are repeated a predetermined number of times. If the measurement result after the repetition is insufficient, an error stop is performed (S6). On the other hand, when it is determined in S4 that the position is within the correctable range, the position correction (coordinate correction) of the coating function is performed by the control mechanism based on the calculated displacement amount between the center position and the reference position (S7). . In order to confirm whether or not the correction has been performed correctly, the processes in S3 and S4 may be performed.

Next, based on the above correction, the silver paste is applied from the application nozzle 17 to the corresponding location (S
8). Thereafter, the quality of the application result is determined (S9). If the result is poor, the processes from S8 to S9 are repeated a predetermined number of times. If the result of the application is not good even after the predetermined number of repetitions, the error is stopped (S11). The determination of the coating failure will be described later.

Next, it is determined whether or not the application has been completed for all the application target locations (S12). When the application has been completed, the TFT array substrate 11 is carried out to the next step (position) (S14). When the application is not completed, the application nozzle 17 is moved to the next application target location, and the application processing of the location is performed in the same procedure (S13). FIG. 5 shows a procedure for determining the quality of the coating. Referring to this figure, first, the monitor camera 7
The visual state of the application state is recognized by the visual device 8 on the basis of the application shape captured by the above (S15), and the applicability of the silver paste is determined based on the area of the application shape, and it is determined whether the silver paste is applied normally. (S16). If it is determined that the silver paste is defective, the application mechanism 6 applies the silver paste at the corresponding location (S17). Thereafter, an image is taken again by the monitor camera 7 (S18), and it is determined by the visual device 8 whether or not the coating has been performed normally (S19).

Although the above is an explanation of an example in which the present invention is applied to the application of silver paste on a TFT array substrate, the present invention can of course be applied to the processing of other substrates that perform similar paste application. It is.

As apparent from the above description, according to the present invention, the correction of the coating position corresponding to one coating target portion is performed based on the displacement amount between the center position of the coating target portion and the reference position.
To be done by Zui, the effect of making it possible plurality of coating target portion on the substrate accurately applies even exist paste each location.

[Brief description of the drawings]

FIG. 1 is an external perspective view showing a configuration of a paste application device according to one embodiment of the present invention.

2 (a) is a front view of an application mechanism constituting the paste application apparatus of FIG. 1, and FIG. 2 (b) is a side view thereof.

FIG. 3 is an explanatory view showing an example of a TFT array substrate on which paste is applied by the paste application apparatus of the present embodiment.

FIG. 4 is a flowchart showing an overall processing procedure in the embodiment.

FIG. 5 is a flowchart illustrating a processing procedure of coating quality in the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positioning part 4 Positioning mechanism 5 Orthogonal robot 6 Coating mechanism 7 Monitor camera 8 Visual device

Continuation of the front page (56) References JP-A-6-334319 (JP, A) JP-A-7-290892 (JP, A) JP-A-7-50467 (JP, A) JP-A-4-17388 (JP) , A) JP-A-2-284672 (JP, A) JP-A-61-115160 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) B05C 5/00, 5/02 B05C 13/02 B05D 1/26 G09F 9/00 338 H05K 3/34 505-512 H05K 3/34 501

Claims (2)

(57) [Claims] 1. A positioning means for positioning a substrate to be processed at a predetermined site, a coating mechanism for coating a paste on each of a plurality of coating target locations on the positioned substrate, and a mounting mechanism attached with the coating mechanism. Monitor turtle
La, and the coating of said monitor camera at the paste applying apparatus provided with a control mechanism for controlling the position of the coating mechanism
Along with the cloth mechanism, it corresponds to one application target location on the substrate.
It is moved to the application position, the center position by capturing the location
A first step of measuring the position, a second step of detecting a displacement amount between the measured center position and a predetermined reference position, and the application mechanism of the application mechanism so that the detected displacement amount is reduced . A method for correcting a coating position in a paste coating device, wherein the third step of correcting the position is performed at least in this order . 2. The method according to claim 1, wherein the third step includes detecting the detected displacement.
It is determined whether or not the amount is within a correctable range. If the amount cannot be corrected, the first and second steps are repeated a predetermined number of times, and the correctable range is determined.
2. The correction method according to claim 1 , wherein the position of the application mechanism is corrected when the position becomes inside .