JP3282008B2 - Paste application method - 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 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 fan electrode for energizing each of the electrodes is provided by the TFT.
It is manufactured by applying a silver paste to an application target (transfer pad) formed on the array substrate. In the case of this silver paste application technique, the application nozzle is set to T
A technique for stabilizing an applied amount and an applied shape by slightly contacting the FT array substrate is widely used.

As a technique for applying such a silver paste, for example, a technique described in JP-A-1-122127 is known. In this conventional example, a moving mechanism for moving the application nozzle closer to or away from the product to be applied is mounted on the application nozzle. The application nozzle is provided with a sensor for detecting contact between the application nozzle and the target product. The operation of the moving mechanism is digitally controlled by a microcomputer using a pulse motor as power.

In this conventional example, the contact between the tip of the application nozzle and the object is detected while gradually approaching the application nozzle to the object to be applied. When the contact is detected, the approach operation of the application nozzle is stopped. The position at that time is stored in the microcomputer. Further, at the time of coating, the microcomputer calculates a position obtained by subtracting a predetermined interval from the position stored above, and drives a pulse motor to move the coating nozzle to the calculated position (a position at a predetermined interval). The coating is performed by moving. With this configuration, an interval for maintaining a constant interval between the application nozzle and the target product is quickly set, and the application shape and the application amount by the application nozzle are stabilized.

[0005]

By the way, generally, the surface of a TFT array substrate to be processed is not completely flat but has some undulations. Further, in an actual apparatus, there is an imperfection in the parallelism between the horizontal axis of the moving mechanism of the application nozzle and the TFT array substrate, so that the distance between the tip of the application nozzle and the substrate differs depending on the location.
For this reason, in the configuration in which the application nozzle is brought into contact with a certain point of the target product and the heights of all the application target locations are determined with reference to the position at that time, as in the above-described conventional example, Due to imperfection or the like, there is a possibility that the tip of the application nozzle collides with the substrate or the application is performed in a state where the application nozzle is not in contact with the substrate. And the application nozzle is TFT
When colliding with the array substrate, there is a possibility that damage to the application nozzle or the application target portion, generation of dust, or scattering of silver paste may occur.

Accordingly, the application nozzle is moved down to a height of about 0.2 mm above the TFT array substrate at a high speed, approached and temporarily stopped, and then the application nozzle is moved from this position by 0.0 mm.
There has also been proposed a technique in which the application nozzle is gradually lowered by 1 mm to detect whether or not the application nozzle and the TFT array substrate have come into contact with each other. Note that the above-mentioned position having a height of about 0.2 mm is a position as a shortest distance at which the application nozzle does not come into contact with any place on the substrate.

However, in the case where the application nozzle is gradually lowered and the presence or absence of contact between the application nozzle and the TFT array substrate is determined as in this technique, the tip of the application nozzle is set to the TFT array substrate at all application target locations. Since the surface is approached at a low speed so as to make slight contact with the surface, it takes a long time to start the application of the silver paste, and as a result, there is a problem that it takes a long time to apply the silver paste.

An object of the present invention is to provide a paste application method capable of applying a silver paste to a plurality of application target locations near each other in a short time in view of the above problems.

[0009]

According to the present invention, there is provided a paste coating method comprising: a plurality of paste coating apparatuses having a plurality of paste nozzles for applying a paste; A method of applying a paste from an end of the application nozzle to each of the application target portions, wherein the application nozzle is configured such that the end of the application nozzle contacts the surface of the substrate at one application target portion. Detecting the relative height of the end portion of the application nozzle and the relative height of the one application target location based on the position information, and applying another application target location other than the one application target location. Raising the end of the application nozzle to a position higher than the detected height, and then lowering the end of the application nozzle to a height intermediate between the current position and the detected height, End of the nozzle is characterized in that repeated until it contacts the surface of the substrate.

The relative height of the one application target portion is detected, for example, by raising the end of the application nozzle to a position higher than the detected height, and then moving the application nozzle toward the substrate. The step of gradually lowering is performed by repeating until the end of the application nozzle comes into contact with the surface of the substrate.

[0011]

In a case where the application target locations are close to each other on a substrate such as a TFT array substrate, for example, when the distance between the application target locations is about 1 to 2 mm, the undulation of the substrate surface and the imperfect parallelism are caused. It can be considered that the height of each application target portion is substantially the same. Therefore, in the present invention, the height of one of the plurality of application target locations is detected and detected, and the elevation of the application nozzle at the other application target location is controlled based on the detected height. That is, the step of moving the end of the application nozzle to a height intermediate between the current position and the detected height is repeated until the application nozzle comes into contact with the substrate.

[0012]

Next, with reference to the drawings, embodiments of the present invention will be described in detail by taking a manufacturing process of a TFT array substrate as an example.

FIG. 1A is a front view of a paste coating apparatus according to an embodiment of the present invention, and FIG. 1B is a side view of the same.
As shown in these drawings, the paste coating apparatus of the present embodiment includes a coating nozzle moving mechanism 1, a coating mechanism base 2, a slide rail 3, a syringe base 4, a syringe holder 5, a tension spring 6, a syringe 7, and a coating nozzle 8. , An air tube 9, a contact detection sensor 10, and a sensor holder 11. In FIG. 1, reference numeral 12 denotes a TFT array substrate.

An application mechanism base 2 is attached to the application nozzle moving mechanism 1, and a syringe base 4 is attached to the application mechanism base 2 via a slide rail 3. With this configuration, the syringe base 4 can move vertically with respect to the coating mechanism base 2. A syringe 7 containing silver paste is held by the syringe base 4 by the syringe holder 5. The syringe 7 has a coating nozzle 8
Is attached. A tension spring 6 is mounted between the application mechanism base 2 and the syringe base. Due to the action of the tension spring 6, a downward load is always applied to the syringe base 4.

A sensor holder 11 is provided on the coating mechanism base 2.
Holds the contact detection sensor 10. The tip of the contact sensor 10 is in contact with the syringe base 4, whereby the displacement of the syringe base 4 can be detected. That is, when the application nozzle 8 comes into contact with the TFT array substrate 12, the syringe base 4 slides,
The contact detection sensor 10 operates.

As shown in FIG. 2, the coating nozzle moving mechanism 1 moves the coating mechanism base 2 in the horizontal direction (X and Y axis directions) and in the vertical direction (Z axis direction) according to a command from the coating nozzle moving mechanism control device 14. Move to Here, as the application nozzle moving mechanism 1 and the application nozzle moving mechanism control device 14, generally available ones as a three-axis orthogonal coordinate type robot can be used. As the application nozzle moving mechanism control device 14, a device having a built-in microcomputer function is used. The application nozzle moving mechanism control device 14 executes a program or a calculation of a predetermined operation procedure in accordance with the microcomputer function, and controls the operation of the application nozzle moving mechanism 1 based on these.

The coating nozzle moving mechanism control device 14
Is input with a signal from the contact detection sensor 10,
Upon receiving this signal, the application nozzle movement control device 14 stops the operation of the application nozzle movement mechanism 1. In this embodiment, the contact detection sensor 10 is of a contact type, but any other type, such as an optical sensor, can be used as long as it can detect the displacement of an object. Further, the application nozzle moving mechanism control device 14 similarly controls the operation of the dispenser 13 connected to the syringe 7 via the air tube 9, whereby the application nozzle 8
The silver paste is ejected from the tip of the silver paste at a predetermined timing by a predetermined amount.

Next, the operation of this embodiment will be described with reference to FIGS. T sent from the previous process not shown
The FT array substrate 12 is positioned and held at a predetermined position in the paste application device of the present embodiment. Where T
The pattern of the application target locations on the FT array substrate 12 varies depending on the product type or the like, but usually, the application target locations are arranged close to each other. Such a TF
An example of the T array substrate 12 is shown in FIG. This TF
At a predetermined position on the T-array substrate 12, an application target portion 15 to which a silver paste 16 is applied is formed. In the illustrated example, two application target locations 15 are arranged near each other.

Referring to FIG. 4, first, the application nozzle 8 is moved over one of the application target locations 15 near each other, that is, on the first application target location (S15). The location of the application nozzle 8 to be moved among the plurality of application target locations in the vicinity or the location of the remaining application target location is previously stored in the memory of the application nozzle movement mechanism control device 14 as type data. Remember.

After the application nozzle 8 is moved above the application target area as described above, the dispenser 13 is operated to discharge a predetermined amount of silver paste, for example (S1).
6). The discharged silver paste adheres to the end of the application nozzle 8 without being separated from the application nozzle 8.

Next, the application nozzle 8 is lowered at a high speed to a height at which the distance between the end of the application nozzle 8 and the TFT array substrate 12 is about 0.2 mm (S17). Here, the interval of about 0.2 mm corresponds to the undulation of the surface of the TFT array substrate 12 or the TFT array substrate 12 and the coating nozzle moving mechanism 1.
Considering imperfect parallelism with the horizontal axis with
This is a value set so that the application nozzle 8 does not come into contact with any position on the T array substrate. Therefore, when the above-mentioned undulation and incomplete parallelism are small, this value can be reduced.

Next, while detecting the contact between the application nozzle 8 and the TFT array substrate 12, the application nozzle 8 is moved by 0.01 m.
It is lowered by m (S17, S18). That is, 0.0
The signal from the contact detection sensor 10 is checked every time the sensor descends by 1 mm.
m is repeated. When the contact is detected, the lowering of the application nozzle 8 is stopped, and the current height of the application nozzle 8 is stored in the application nozzle moving mechanism control device 14 (S20). Thereafter, the application nozzle 8 is raised (S21). As a result, the silver paste attached to the end of the application nozzle 8 is transferred to the first application target portion of the TFT array substrate 12.

Next, based on the position data including the above-mentioned height stored in the application nozzle moving mechanism control device 14, another application target location (second location) near the first application target location.
The application nozzle 8 is moved to the sky above the application target portion (S22). In the same manner as above, the dispenser 13 is operated to discharge a predetermined amount of silver paste (S23).
It is attached to the end of the application nozzle 8. Next, the distance between the end of the coating nozzle 8 and the TFT array substrate 12 is about 0.2 m.
m, the application nozzle 8 is lowered at a high speed (S
24). This state is shown in FIG.

Next, the application nozzle moving mechanism control device 14
Thus, the difference between the current height of the application nozzle 8 and the stored height, that is, the dimension a in FIG. 5 is obtained. next,
The application nozzle 8 is lowered by a distance between the current height of the application nozzle 8 and the stored height, that is, a distance that is １ ／ of the dimension a (S25). The position of the application nozzle 8 after this lowering is shown by the dimension b in FIG. Then, in this state, the application sensor 8 is
The presence or absence of contact between the TFT array substrate 12 and the
26). If not, S25 and S26 are repeated.
Is repeated. In this repetitive operation, the descending distance of the application nozzle 8 gradually decreases, and as a result,
While gradually lowering the descending speed of the coating nozzle 8, the TF
It will be close to the T array substrate 12.

If the contact detection sensor 10 finally detects that the application nozzle 8 has come into contact with the TFT array substrate 12, the application nozzle 8 is moved up (S27). Thereby, the silver paste attached to the end of the application nozzle 8 is transferred to the TFT array substrate 12.

In the paste coating apparatus of the present embodiment configured as described above, the coating nozzle 5 can descend and contact at high speed without suddenly colliding with the TFT array substrate 1. Specifically, in this type of conventional apparatus, 1
The descent time, which took 3 seconds per coating target,
In the configuration of the present embodiment, the time can be reduced to one second. Also, the application state could be made equal to that of the conventional apparatus. The above description is for the case where the present invention is applied to silver paste application on a TFT array substrate. However, it goes without saying that the present invention can be applied to processing of other substrates that perform similar paste application.

[0027]

As described above, according to the present invention, it is possible to provide a paste application method capable of performing a good application in a short time when applying a paste to a plurality of application target locations near each other. it can.

[Brief description of the drawings]

FIG. 1A is a front view of a paste coating apparatus according to one embodiment of the present invention, and FIG.

FIG. 2 is a block diagram of a paste application device of the present embodiment.

FIG. 3A is a plan view showing an example of a TFT array substrate to be processed by the paste coating apparatus of the present embodiment,
(B) is a sectional view of a transfer pad portion of the substrate.

FIG. 4 is a flowchart showing an operation procedure in the paste application device of the present embodiment.

FIG. 5 is an explanatory diagram of a lifting / lowering operation of a coating nozzle in the paste coating device of the present embodiment.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 coating nozzle moving mechanism 2 coating mechanism base 3 slide rail 4 syringe base 5 syringe holder 7 syringe 8 coating nozzle 10 contact detection sensor 12 TFT array substrate 14 coating nozzle moving mechanism control device

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) B05D 1/26 B05D 3/00 G09F 9/00 338 H05K 3/34 505 B05C 5/00

Claims (2)

(57) [Claims] 1. A paste is applied from an end of the application nozzle to each of a plurality of application target locations adjacent to each other on a processing target substrate installed at a predetermined portion of a paste application device having a coating nozzle for applying the paste. A method of applying, wherein the relative height of the end of the application nozzle based on the positional information of the application nozzle when the end of the application nozzle contacts the surface of the substrate in one application target location The relative height of the one application target location is detected, and when applying other application target locations other than the one application target location, the end of the application nozzle is raised to a position higher than the detected height. Then, the step of lowering the end of the application nozzle to a height intermediate between the current position and the detected height is repeated until the end of the application nozzle comes into contact with the surface of the substrate. Paste coating method to. 2. The detection of the relative height of the one application target portion includes raising an end of the application nozzle to a position higher than the detected height, and then gradually lowering the end to the substrate side. 2. The paste coating method according to claim 1, wherein the step of performing is performed by repeating until the end portion contacts the surface of the substrate.