KR101346782B1 - Method for determining the amount of liquid crystal based on the state of dispensed sealant - Google Patents

Abstract

The present invention discloses a method for determining liquid crystal dropping amount based on a sealant coating state. According to the invention, the step of mounting the substrate on the stage of the sealant coating device; Applying the sealant in a predetermined pattern by the dispensing head on the substrate; Detecting a defective portion of the sealant pattern and calculating a defective portion volume of the sealant pattern; Calculating a liquid crystal dropping amount required for the calculated defective area volume; And providing the calculated liquid crystal dropping amount to the liquid crystal dropping device.

Sealant pattern, bad position, liquid crystal.

Description

Method for determining the amount of liquid crystal based on the state of dispensed sealant}

The present invention relates to a liquid crystal dropping amount determining method based on a sealant coating state which enables the amount of liquid crystal to be dropped onto a substrate by calculating the volume of the defective portion of the sealant pattern formed on the substrate.

Liquid crystal displays (LCDs) have better visibility than cathode ray tubes (CRTs), have lower average power consumption and generate less heat than CRTs of the same screen size. Along with field emission display (FED), it is attracting attention as the next generation display device in the field of mobile phone, computer monitor, and television.

Thin Film Transister (TFT) LCDs include a TFT array substrate and a color filter array substrate. The two substrates are separated by approximately 4 to 5 μm, and a liquid crystal layer is formed therebetween. In the periphery of the screen display area, the sealant bonds the two substrates, while preventing moisture or contaminants from entering the liquid crystal layer.

The sealant coating device applies a sealant that bonds two substrates as described above. The sealant coating device controls a dispensing head including a stage for seating a substrate, a dispensing head including a nozzle through which the sealant is discharged, a head support for supporting the dispensing head, a motor for moving the head support, and a motor for moving the dispensing head. It is configured to include a control unit. Then, a syringe containing a sealant is connected to the nozzle.

Such a sealant coating device forms a sealant pattern having a predetermined shape on the substrate while changing relative positions of the substrate and the nozzle. That is, when the sealant is applied, the substrate is moved in one direction, and the dispensing head on the head support is moved in a direction perpendicular to the moving direction of the substrate.

1 is a perspective view illustrating a dispensing head of a sealant coating apparatus according to the related art, and FIGS. 2 and 3 are views for explaining a method of inspecting a sealant pattern formed on a substrate.

As shown in FIG. 1, the conventional dispensing head 100 includes a main block 101 installed on a head support (not shown) of a sealant coating device and a syringe 105 containing a sealant detachably installed. A head block 104, a horizontal drive unit 102 capable of moving the head block 104 in a direction perpendicular to the head support, and a nozzle (not shown) mounted to the lower end of the syringe 105. .

The horizontal drive unit 102 includes a linear motion device, such as a servo motor and a linear motion device including a drive shaft connected thereto. The horizontal driver 102 serves to set the position of the nozzle with respect to the substrate by horizontally reciprocating the head block 104 in the front-rear direction.

The main block 101 is provided with a first Z-axis motor 107. The 1st Z-axis motor 107 adjusts the vertical position of a nozzle by moving the horizontal drive part 102 up and down. The main block 101 is provided with a second Z-axis motor 108. The second Z-axis motor 108 seats the substrate on a stage (not shown), and then finely adjusts the height of the nozzle to accurately match the gap between the nozzle and the substrate. Of course, the height of the nozzle is not provided with the second Z-axis motor 108 in the main block 101, it may be adjusted only by the first Z-axis motor 107.

The nozzle may move laterally by moving the main block 101 laterally along the head support. One side of the head block 104 is provided with a first sensor 109a and a second sensor 109b. The first sensor 109a is installed in front of the nozzle in the direction in which the sealant is applied. The first sensor 109a measures the relative position between the nozzle and the substrate surface while applying the sealant on the substrate. Sealant application according to the relative position between the nozzle and the substrate surface makes it possible to consistently apply the sealant on the substrate. The second sensor 109b measures the cross-sectional area of the sealant applied in a predetermined pattern on the substrate.

As shown in FIG. 2, the second sensor 109b is provided with a lens 109c which reciprocates from side to side. The second sensor 109b continuously emits a laser beam through the lens 109c toward the substrate S to scan the sealant pattern P. Therefore, the second sensor 109b can measure the cross-sectional area of the sealant pattern P coated on the substrate S. FIG.

In order to examine whether the sealant pattern P is properly formed on the substrate S, the cross-sectional area is measured at a predetermined position on the sealant pattern P. FIG. When the defective area is not detected as a result of measuring the cross-sectional area at a predetermined position on the sealant pattern P, the substrate S on which the sealant pattern P is formed is moved to a liquid crystal dropping device (not shown) by a robot or the like. Then, the liquid crystal is dropped on the substrate S moved by the liquid crystal dropping device at regular intervals.

However, if the sealant is applied less or more than the reference amount, the sealant pattern may not be formed properly on the substrate. In this case, the liquid crystal dropping device according to the related art drops liquid crystals by reference amount on the substrate without compensation for the excess or lack of the sealant due to the failure of the sealant pattern formed in the sealant coating device. For example, when the sealant is formed on the substrate more than the reference amount, even if a portion of the sealant pattern becomes wider than the defect, the liquid crystal is applied at the reference amount, and the liquid crystal overflows out of the sealant pattern in the process of bonding between the two substrates. Can be. Accordingly, there may be a problem that LCD failure occurs.

The present invention is to solve the above problems, in consideration of the state of the sealant is applied on the substrate to determine the amount of liquid crystal to be dropped on the substrate, based on the sealant coating state that can prevent defects in LCD manufacturing Its purpose is to provide a method for determining liquid crystal dropping amount.

In order to achieve the above object, the present invention is a method for determining a liquid crystal dropping amount to be dropped on a substrate coated with a sealant pattern in a predetermined pattern by a sealant coating device, the defective portion of the predetermined sealant pattern applied Detecting and calculating a volume of a defective portion of the sealant pattern; Providing the calculated defective area volume to a liquid crystal dropping device; And compensating for the liquid crystal dropping amount more or less than a predetermined reference amount based on the calculated defective area volume by the liquid crystal dropping device. The liquid crystal dropping amount determining method based on the sealant coating state is provided.

The liquid crystal dropping amount determining method based on the sealant coating state according to the present invention is a liquid crystal to be dropped onto the substrate in consideration of the excess amount or the insufficient amount of the sealant, even if the sealant pattern defect occurs as the sealant is applied to the substrate less or more than the reference amount By determining the amount can have the following effects.

First, even if a portion of the sealant pattern has a wider defect, the liquid crystal overflows out of the sealant pattern in the process of bonding between the two substrates during LCD manufacturing by adjusting the liquid crystal dropping amount by compensating the excess amount of the sealant. Can be prevented.

In addition, even if a defect in which the width becomes narrow in a part of the sealant pattern occurs, the liquid crystal dropping amount is adjusted by compensating for the insufficient amount of the sealant, thereby preventing the liquid crystal layer defect from occurring due to the lack of liquid crystal between the two substrates during LCD manufacturing. Can be. As a result, the effect of preventing LCD defects can be obtained.

The liquid crystal dropping determination method based on the sealant coating state according to the present invention comprises the steps of: seating a substrate on the stage of the sealant coating device; Applying a sealant in a predetermined pattern on the substrate by a dispensing head; Detecting a defective portion of the sealant pattern and calculating a defective portion volume of the sealant pattern; Calculating a liquid crystal dropping amount required for the calculated defective portion volume; And providing the calculated liquid crystal dropping amount to the liquid crystal dropping device.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is a perspective view illustrating a sealant coating apparatus to which a liquid crystal dropping amount determining method based on a sealant coating state according to an embodiment of the present invention is applied, and FIG. 5 is a dispensing head of the sealant coating apparatus shown in FIG. 4. It is a front view which shows the state which sealant is apply | coated.

4 and 5, the sealant coating apparatus includes a main body 10, a stage 40 installed on the main body 10 to seat the substrate S, and stage moving means for moving the stage 40 back and forth. And a pair of head supports 50 moving relative to the stage 40 along the moving direction of the stage 40 and the head support 50 to move in a direction perpendicular to the moving direction of the head support 50. A plurality of dispensing heads 30 installed on the substrate S and a control unit controlling the amount of application of the sealant connected to the dispensing head 30 and applied on the substrate S; Not shown).

The head support 30 is in the form of a gantry. The dispensing head 30 measures the cross-sectional area of the first sensor 34 measuring the gap between the nozzle 36 from which the sealant is discharged and the surface of the substrate S, and the sealant pattern applied to the surface of the substrate S. FIG. A second sensor (not shown) is provided.

In the sealant coating apparatus configured as described above, a liquid crystal dropping amount determining method based on the sealant coating state according to an embodiment of the present invention will be described with reference to FIG. 6 along with FIGS. 4 and 5.

First, the substrate S is seated on the stage 40. To this end, the pair of head supports 50 move in opposite directions so that the substrate S can be seated on the stage 40 through the space between the head supports 50. The substrate S is absorbed and fixed to the stage 40 by air sucked into a through hole (not shown) formed on the stage 40.

When the substrate S is thus fixed on the stage 40, the pair of head supports 50 return to their application position. Then, the interval between the surface of the substrate S and the end of the nozzle 36 is set to a predetermined value. Subsequently, the stage 40 is moved by the stage moving means in a direction perpendicular to the head support 50 while the dispensing head 30 is moved along the head support 50 on the head support 50 or the stage ( As the dispensing head 30 moves without the 40 moving, the sealant is applied to the surface of the substrate S with a closed-loop of approximately square shape.

The first sensor 34 is provided adjacent to the nozzle 36 so that the sealant can be uniformly applied onto the substrate S. As shown in FIG. The controller (not shown) is connected to the first sensor 34 by wireless or wired. Here, the data obtained from the first sensor 34 may be transmitted and stored in real time to the controller. The control unit calculates a relative distance between the substrate S surface and the nozzle 36 based on the data obtained by the first sensor 34. In addition, the controller compares the calculated interval value with the set value to maintain the interval between the surface of the substrate S and the nozzle 36 at the set value. Accordingly, the sealant may be uniformly applied onto the substrate S.

After the sealant is applied to the substrate S in a predetermined pattern, a process of checking whether the sealant is properly applied as set is performed. This process may be performed by comparing the cross-sectional area of the sealant pattern at any location on the reference cross-sectional area and the sealant pattern.

To this end, the first sensor 34 may detect a sealant pattern position where the relative spacing between the nozzle 56 and the surface of the substrate S exceeds an allowable range, that is, a defective portion of the sealant pattern. If it is determined that the cross-sectional area of the sealant pattern is defective by the first sensor 34 at the inspection position, the second sensor may scan a defective portion of the sealant pattern. Then, the controller may calculate the volume of the defective portion by calculating the cross-sectional area of the defective portion of the sealant pattern based on the data obtained from the second sensor and comparing it with the reference cross-sectional area. On the other hand, the second sensor may scan the sealant pattern at the sealant pattern position where defects occur very frequently.

The defect of the sealant pattern may be, for example, in the form shown in FIGS. 7 and 8.

The sealant pattern P1 illustrated in FIG. 7 has a defective portion E1 in which some portions are narrower in width than other portions. This phenomenon may occur when the gap between the nozzle 36 and the surface of the substrate S is larger than the set gap. In this case, the controller receives the cross-sectional area data measured by the second sensor at the defective portion E1 of the sealant pattern P1 to calculate the volume of the defective portion E1, in detail, the inner volume of the defective portion E1. do. Then, the controller calculates the amount of liquid crystal drop required for the inner volume of the defective portion E1 of the sealant pattern P1. That is, the controller calculates the amount of liquid crystal dropping that can compensate for the insufficient amount of the sealant corresponding to the decrease in the inner volume of the defective portion E1 of the sealant pattern P1.

As such, when data on the amount of liquid crystal compensating for the shortage of the sealant is obtained, the controller may provide the obtained data on the amount of liquid crystal dropping to a liquid crystal dropping device (not shown). The liquid crystal dropping device adjusts the amount of liquid crystal to be dropped more than the reference amount according to the data provided from the control unit of the sealant coating device, and then drops the liquid crystal in the space defined by the sealant pattern P1 on the substrate S. FIG. Therefore, it is possible to prevent the phenomenon that the liquid crystal layer defects due to the lack of liquid crystal between the two substrates in the LCD manufacturing.

Next, the sealant pattern P2 illustrated in FIG. 8 has a defective portion E2 in which some portions are wider than other portions. This phenomenon may occur when the gap between the nozzle 36 and the surface of the substrate S is smaller than the set gap. In this case, the controller receives the cross-sectional area data measured by the second sensor at the defective portion E2 of the sealant pattern P2 to calculate the inner volume of the defective portion E2. Next, the controller calculates a liquid crystal drop amount that can compensate for the excess amount of the sealant corresponding to the increase amount of the defective portion E2 of the sealant pattern P2.

As such, when data on the amount of liquid crystal dropping to compensate for the excess amount of the sealant is obtained, the controller may provide the obtained liquid crystal dropping amount to the liquid crystal dropping device. The liquid crystal dropping device adjusts the amount of liquid crystal to be lower than the reference amount according to the data provided from the control unit of the sealant coating device, and then drops the liquid crystal in the space defined by the sealant pattern P2 on the substrate S. FIG. Therefore, it is possible to prevent a phenomenon that the liquid crystal overflows out of the sealant pattern P2 in the process of bonding between the two substrates during LCD manufacturing. As a result, LCD failure can be prevented.

As another example, the control unit calculates data on the inner volume of the defective portion E1 (E2) of the sealant pattern P1 (P2) before calculating the liquid crystal drop amount that can compensate for the shortage or excess of the sealant. It is also possible to provide a liquid crystal dropping device.

In this case, the liquid crystal dropping apparatus may calculate the amount of liquid crystal drop required for the inner volume of the defective portion E1 (E2) of the sealant patterns P1 and P2 based on the provided calculation data. That is, the control unit of the liquid crystal dropping apparatus calculates the liquid crystal dropping amount which can compensate for the insufficient amount or the excess amount of the sealant corresponding to the inner volume reduction amount or the increase amount of the defective portion E1 (E2) of the sealant patterns P1 and P2. can do.

Subsequently, the liquid crystal dropping device compares the calculated liquid crystal dropping amount with the reference amount, adjusts the amount of liquid crystal to be dropped, and then controls to drop the liquid crystal in the space defined by the sealant patterns P1 and P2 on the substrate S. have.

On the other hand, it is preferable that the liquid crystal dropping device is controlled to drop the liquid crystal in view of the shape of the defective portion of the sealant patterns P1 and P2. That is, the defective portion E2 of the sealant pattern P2 illustrated in FIG. 8 protrudes into the sealant pattern P2 as it becomes wider than other portions. Without considering the shape of the defective portion E2 of the sealant pattern P2, when the liquid crystal dropping device drops the liquid crystal into the sealant pattern P2, the liquid crystal may flow out of the sealant pattern P2. Therefore, when the defective portion of the sealant pattern P2 becomes wider than other portions, the liquid crystal dropping apparatus needs to be controlled so that the liquid crystal does not flow out of the sealant pattern P2 at the defective portion E2.

Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely exemplary, and any person skilled in the art to which the present invention pertains may have various modifications and equivalent other embodiments. Will understand. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

1 is a perspective view showing a dispensing head of a conventional sealant coating device.

2 and 3 are views for explaining a method of inspecting a sealant pattern formed on a substrate by a sensor provided in a head block of a conventional sealant coating device.

4 is a perspective view illustrating a sealant coating apparatus to which a liquid crystal dropping amount determining method based on a sealant coating state according to an embodiment of the present invention is applied.

FIG. 5 is a front view showing a state where the sealant is applied by the dispensing head of the sealant applying device shown in FIG. 4. FIG.

6 is a flowchart illustrating a method for determining a liquid crystal drop amount based on a sealant coating state according to an embodiment of the present invention.

FIG. 7 is a view illustrating a defective state in which a portion of the sealant pattern is narrower than other portions of the sealant pattern. FIG.

FIG. 8 is a view illustrating a defective state in which a portion of the sealant pattern is wider than other portions of the sealant pattern. FIG.

<Explanation of symbols for each major part of drawing>

10: main body 30: dispensing head

34: First sensor 36..Nozzle

40: stage 50: head support

E1, E2..Defective area L..Liquid crystal

P, P1, P2..Sealer pattern S..substrate

Claims (4)

A method for determining a liquid crystal dropping amount to be dropped onto a substrate coated with a sealant pattern in a predetermined pattern by a sealant coating device, Detecting a defective portion of the coated sealant pattern and calculating a defective portion volume of the sealant pattern; Providing the calculated defective area volume to a liquid crystal dropping device; And Compensating for the liquid crystal dropping amount more or less than a predetermined reference amount based on the calculated defective area volume by the liquid crystal dropping device; Liquid crystal dropping amount determination method based on the sealant coating state containing a. The method according to claim 1, The defective portion of the sealant pattern is detected by the use of a first sensor, and the defective portion volume of the sealant pattern is calculated by the use of a second sensor. The method of claim 2, The sealant volume of the sealant pattern is calculated by calculating a cross-sectional area of the defective portion of the sealant pattern based on the data obtained from the second sensor, and then comparing the calculated cross-sectional area with a reference cross-sectional area. Liquid crystal dropping determination method based on the coating state. A liquid crystal dropping device receiving volume data on a defective portion of a sealant pattern applied in a predetermined pattern on a substrate; Calculating, by the liquid crystal dropping device, a liquid crystal dropping amount more or less than a predetermined reference amount based on the volume data of the defective portion; And Dropping liquid crystal into the space defined by the sealant pattern on the substrate by the liquid crystal dropping device using the calculated liquid crystal dropping amount; Liquid crystal dropping amount determination method based on the sealant coating state containing a.

Images