KR101288990B1 - Apparatus for protecting dispenser condensation and method for operating the same - Google Patents

Abstract

The present invention relates to an apparatus for preventing liquid condensation of a dispenser and a method for preventing liquid condensation. The present invention relates to an apparatus and an operation method for preventing liquid condensation from occurring at a nozzle end when a raw material such as liquid crystal or paste is applied to a glass substrate. will be. An embodiment of the present invention is a pressure control valve for adjusting the supply pressure to the inside of the syringe, a pressure head sensor to detect the pressure head of the raw material in the syringe, and the pressure control valve in accordance with the detected pressure head It includes a pressure control device for controlling. An embodiment of the present invention is to detect the pressure head of the raw material in the syringe, the process of calculating the residual pressure corresponding to the pressure head, and supplying the residual pressure to the inside of the syringe in the form of negative pressure Process.

Description

Apparatus for protecting dispenser condensation and method for operating the same}

The present invention relates to an apparatus for preventing liquid condensation of a dispenser and a method for preventing liquid condensation. The present invention relates to an apparatus and an operation method for preventing liquid condensation from occurring at a nozzle end when a raw material such as liquid crystal or paste is applied to a glass substrate. will be.

A liquid crystal display (LCD) forms a plurality of pixel patterns on one glass substrate, forms a color filter layer on the other opposite glass substrate, and then bonds the two glass substrates together, and joins the two glass substrates together. It is produced in such a way that the liquid crystal is injected into the space formed by the sealant by a predetermined method.

In the manufacturing process of the above-described liquid crystal display device, the paste is applied to the glass substrate in a predetermined pattern by the paste coating device.

A coating apparatus for applying a paste onto a flat glass substrate includes a dispenser including a stage on which an upper substrate and a lower substrate are placed, a syringe filled with a raw material (paste), and a nozzle for discharging the paste onto a glass substrate on the stage. It includes a sensor for measuring the gap (gap) between the glass substrate and the nozzle, a drive unit for lifting and lowering the dispenser, a transfer unit for moving the dispenser horizontally and a control unit for controlling the operation of the dispenser.

In order to form a pattern on the glass substrate using the coating apparatus, first, a gap between the glass substrate and the nozzle is measured using a sensor. The dispenser is raised or lowered to adjust the gap between the glass substrate and the nozzle. Thereafter, the dispenser is moved while discharging the raw material from the nozzle to form a paste pattern having a desired shape.

For example, when the paste pattern is formed at the edge of the glass substrate for a single panel, the paste pattern 20 has a shape as shown in FIG. As shown in FIG. 1, the paste pattern 20 has a shape surrounding the center of the glass substrate 10 at the upper edge of the glass substrate 10. Here, the paste pattern 20 is composed of a straight portion 23 having a uniform width and height of a portion located at the edge of the glass substrate 10 except for each corner. In addition, the paste pattern 20 is formed of curved portions 22 at portions located at each corner of the glass substrate 10 so as to have a uniform width and height throughout the paste pattern 20.

Therefore, the paste pattern 20 is formed by applying the starting point 21 to the starting point, turning the straight line 23 and the curved portion 22 to reach the end point 24 immediately before the starting point 21.

By the way, after the paste pattern application is completed, there is a waiting time to form the next paste pattern, at which time liquid droplets (drops) occur at the end of the nozzle. This is caused by the raw material at the bottom of the nozzle agglomerates by the pressure of the remaining amount of the syringe, a phenomenon that occurs over time regardless of the viscosity of the raw material.

Due to this liquid condensation, many raw materials are unintentionally applied at the beginning of the next paste pattern, resulting in a problem that the height of the paste pattern as a whole becomes uneven.

In order to prevent such liquid condensation, the remaining pressure is maintained at a fixed value, or a method of touching the nozzle end on the other side of the glass substrate to prevent the liquid from coming out of the nozzle is used. However, when the residual pressure is kept at a fixed value, liquid condensation still forms depending on the amount of liquid used, or conversely, liquid is sucked into the nozzle, and the method of bringing the nozzle end to the surface of the glass substrate contaminates the nozzle area. And further damage the nozzle.

The technical problem of the present invention is to prevent condensation from occurring at the end of the nozzle of the dispenser. In addition, the technical problem of the present invention is to control the pressure inside the syringe of the dispenser after applying the raw material and before applying the next raw material. In addition, the technical problem of the present invention is to control the pressure in the syringe in consideration of the remaining amount of raw material in the syringe.

An embodiment of the present invention is a pressure control valve for adjusting the supply pressure to the inside of the syringe, a pressure head sensor to detect the pressure head of the raw material in the syringe, and the pressure control valve in accordance with the detected pressure head It includes a pressure control device for controlling.

An embodiment of the present invention is to detect the pressure head of the raw material in the syringe, the process of calculating the residual pressure corresponding to the pressure head, and supplying the residual pressure to the inside of the syringe in the form of negative pressure Process.

The process of calculating the residual pressure, the correction constant value is a constant value showing the specific gravity of the raw material material in contrast to the specific gravity of water '1', the pressure value corresponding to 1mm of water is 0.0001 [kgf / cm ² ] The unit conversion constant value is 98.0665 which converts the pressure value kgf / cm ² unit into kPa unit, and H is the residual pressure [kPa] = correction constant value × water when the pressure head of the raw material in the syringe is used. It calculates by the pressure value [kgf / cm < ² > x unit conversion constant value x H [mm] corresponding to 1 mm.

An embodiment of the present invention provides a process for determining a pressure head of a raw material in a syringe, calculating a residual pressure corresponding to the pressure head, and supplying the residual pressure to the inside of the syringe in the form of a negative pressure. Process.

According to embodiment of this invention, generation | occurrence | production of liquid condensation can be prevented at the tip of the nozzle of a dispenser. In addition, by preventing the liquid condensation, it is not necessary to clean the nozzle at the end of each unit process, thereby improving work efficiency. In addition, it is possible to improve the nonuniformity of the application of the raw material due to the liquid condensation. In addition, it is possible to achieve quality improvement due to improved uniformity of the application of the raw material.

FIG. 1 is a view illustrating a paste pattern formed on an edge of a glass panel for a single panel.
2 is a perspective view of a paste coating device.
Figure 3 is a simplified view of the device for preventing the liquid condensation of the syringe nozzle according to an embodiment of the present invention.
4 is a flowchart illustrating a process of calculating a pressure value according to a pressure head of a raw material according to an embodiment of the present invention and adjusting the pressure in the syringe accordingly.
FIG. 5 is a view showing a state in which raw materials are aggregated along the inner wall of the cylinder due to the stress of the raw materials.
6 is a flowchart illustrating a process of adjusting the pressure in the syringe after extracting the residual pressure for each pressure head from the table according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It will be apparent to those skilled in the art that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know. Wherein like reference numerals refer to like elements throughout.

2 is a perspective view of a paste coating device.

In the following description, a paste coating device will be described as an example of a dispenser, but it will be apparent that the present invention can be applied to various raw material coating devices such as a liquid crystal coating device as well as a paste coating device.

According to an embodiment of the present invention, a coating apparatus may include: a nozzle 30 forming a paste pattern 20 by discharging a raw material onto a stage 30 on which a glass substrate is placed and a glass substrate 10 on the stage 30. 130 with a dispenser 100.

The substrate S may be any one of an upper substrate and a lower substrate used in the liquid crystal display panel. At this time, although not shown in the upper substrate, for example, a color filter and a common electrode are formed, and in the lower substrate, for example, a plurality of thin film transistors and a pixel electrode are formed. When the upper substrate and the lower substrate are bonded to each other to form a liquid crystal display panel, a plurality of patterns (P; patterns) made of a metal paste are formed on any one of the upper substrate and the lower substrate for energizing the upper substrate and the lower substrate. It is preferable. In the embodiment, silver (Ag) paste is used as a raw material stored in a syringe (syringe) of the dispenser and applied onto the glass substrate (S).

The dispenser 100 moves in the X-axis and Y-axis directions by the transfer unit to form a pattern P on the glass substrate S. FIG. At this time, the stage and the dispenser 100 are moved by using a driving means (driving motion) such as a motor and a rail. Of course, various other means can be used. The plurality of dispensers are moved through one driving means (driving motion), and these driving means are driven for all the dispensers simultaneously through the control of one transfer unit.

In the above, the dispenser 100 has been described as horizontally moving in the X-axis and Y-axis directions. However, the present invention is not limited thereto, and the stage may move in the X-axis and Y-axis directions to apply the raw material to the glass substrate 10. In addition, both the stage and the dispenser 100 may move in the X-axis and Y-axis directions to apply the raw material, and the stage may move in the one-axis direction and the dispenser 100 may move in the other axis direction. The coating substance may also be applied.

In addition, although not shown, the dispenser includes a distance sensor (not shown). The distance sensor is spaced apart from the nozzle 130 to measure a gap between the nozzle 130 of the dispenser 100 and the glass substrate 10. The distance sensor includes a light emitting unit (not shown) for outputting distance measuring light toward the glass substrate 10 and a light receiving unit (not shown) for receiving the light emitted from the light emitting unit (not shown). At this time, the light receiving unit (not shown) of the light emitting unit (not shown) is made of a body, it is preferably disposed spaced a predetermined distance. Then, the dispenser 100 is moved up and down using the measured value measured from the distance sensor to adjust the gap between the glass substrate 10 and the nozzle 130 to be 40 μm, for example.

By the way, after the paste pattern application is completed, there is a waiting time for forming the next paste pattern, at which time liquid droplets (drops) occur at the end of the nozzle 130. The raw material at the bottom of the nozzle is agglomerated by the pressure of the remaining amount of the syringe.

In order to prevent the liquid condensation at the nozzle end, an embodiment of the present invention checks the remaining amount of raw material in the syringe remaining after applying the paste, and maintains the internal pressure of the syringe to prevent liquid condensation according to the remaining amount. Perform control. It demonstrates with FIG.

Figure 3 is a simplified view of the device for preventing the liquid condensation of the syringe nozzle according to an embodiment of the present invention.

The syringe 120 filled with the raw material is mounted on the head unit 120 constituting the dispenser 100, and the nozzle 130 is mounted under the syringe. The raw material filled in the syringe 120 is discharged to the outside through the nozzle 130, thereby forming a paste pattern on the glass substrate 10 placed on the stage.

A pressure supply tank 200 for providing pressure in the syringe is provided, and a pressure supply pipe 450 for connecting the pressure supply tank 200 and the syringe 110 is provided. The pressure supply pipe 450 is provided with a pressure control valve 400 for adjusting the pressure of the gas supplied from the pressure supply tank 200 to the syringe 110.

The pressure supply tank 200 is provided with a VACUMM module 210 for supplying a vacuum pressure, ATM module 220 for supplying atmospheric pressure, CDA module 230 for supplying compressed air as a unit module. Each unit module is connected in parallel to the gas supply line through each valve, allowing the syringe to be maintained at atmospheric, vacuum, and specific pressure levels. For reference, the CDA (Clean Dryer Air) module is a module for supplying the optimum compressed air to remove the contamination (dust, oil, moisture, etc.) contained in the compressed air within the reference value, and N2 gas pressure control and Together is the most used pressure supply.

The syringe 110 is provided with a pressure head sensor 111. The pressure head sensor 111 detects the pressure head of the raw material remaining in the syringe after applying the raw material. The pressure head sensor may be provided inside or outside the syringe.

Although the pressure head sensor 111 is used as a method for detecting the pressure head of the raw material, various methods may be applied without being limited thereto. For example, a discharge time may be applied to the capacity of the raw material discharged through the nozzle of the syringe. The pressure head can be calculated based on the total discharged capacity calculated by multiplying by.

The said pressure head is a unit which shows the magnitude | size of the pressure which flow water has as a height, and displays a magnitude of pressure as a height of water. That is, if the pressure is the unit volume weight of ρkg / m ² water is γkg / m ³ , there is a relationship of the pressure head h = p / γ, and the pressure head is expressed in units of this length. For example, a pressure head of 10 m corresponds to about 1 kg / cm.

The pressure control device 300 controls and adjusts the pressure in the syringe to a negative pressure in consideration of the pressure head of the raw material detected through the syringe 111. In the paste pattern application, the raw material in the syringe is initially filled, and after the paste pattern operation, the raw material in the syringe is discharged so that the pressure of the raw material in the syringe is different from the initial state. That is, the difference in pressure head will generate | occur | produce in a syringe after the state before paste application and after paste application.

Therefore, before the paste is applied, the raw material is filled with the initial pressure in the syringe, while after the paste is applied, it is different from the initial pressure. Therefore, if the negative pressure is maintained with reference to the pressure head in the initial state, liquid condensation occurs at the nozzle end.

Therefore, in the embodiment of the present invention, the pressure in the syringe is adjusted to a negative pressure in consideration of such a pressure head difference in consideration of the fact that the raw material in the syringe is discharged due to the paste coating to generate a pressure head difference in the syringe. The valve is controlled to prevent condensation at the tip of the nozzle. Hereinafter, the negative pressure means that the pressure inside the syringe is a pressure state in a negative ('-') direction from a vacuum state, and refers to a pressure force pulling into the inside of the syringe and not outside the nozzle.

For reference, it is difficult to implement negative pressure through a single pressure control module such as a general vacuum module, a CDA module, and a pressure gauge module. This is because the conventional pressure regulation module is difficult to control as a single sound pressure as a single module. Accordingly, embodiments of the present invention are configured to provide a negative pressure by combining a plurality of pressure regulation modules. For example, the pressure control device can be implemented to provide a desired negative pressure inside the syringe by supplying (fixing) the vacuum pressure through a single vacuum module and adjusting and providing the CDA amount of a single CDA module. have.

4 is a flowchart illustrating a process of calculating a pressure value according to a pressure head of a raw material according to an embodiment of the present invention and adjusting the pressure in the syringe accordingly.

First, when the raw material is applied and then enters the standby mode, it has a process of detecting the pressure head (residual height) of the raw material filled in the cylinder (S41). As a method for detecting the pressure head in the syringe of the raw material, various known methods may be applied. For example, a sensor for measuring the pressure head may be used. Alternatively, after determining the total discharged amount calculated by multiplying the discharge time by the discharge time per hour of the raw material discharged through the nozzle of the syringe, it is possible to determine the pressure head by subtracting the consumption from the total capacity of the syringe.

After detecting the pressure head (S41), the pressure head in the determined length unit is converted into the residual pressure in the pressure value unit (S42). The calculation formula is as follows.

[Formula 1]

Residual pressure [kPa] = Correction constant value × Pressure value corresponding to 1 mm of water [kgf / cm ² ] × Unit conversion constant value × H [mm]

In the above description, the correction constant value is a constant value indicating the specific gravity of the raw material material when the specific gravity of water is '1', and the pressure value corresponding to 1 mm of water is 0.0001 [kgf / cm ² ], and the unit conversion constant value is It is 98.0665 which converts the pressure value kgf / cm <^2> into kPa unit, and H is the head of the raw material pressure head in a syringe. Therefore, the residual pressure can be calculated by the correction constant value × 0.0001 × 98.0665 × H. In the above, the residual pressure refers to the pressure that the residual raw material material discharged from the cylinder exerts downward in the cylinder.

When the pressure head is converted and calculated as the residual pressure as described above, the calculated residual pressure is supplied to the inside of the syringe as the syringe adjustment pressure in the form of negative pressure (S43). For example, when the residual pressure in the syringe is calculated to be 0.5 [kPa], the inside of the syringe is supplied as a syringe adjustment pressure of -0.5 [kPa]. Since the inside of the syringe is provided with a negative pressure in the form of negative pressure as opposed to the residual pressure, the raw material is not discharged from the nozzle, and no liquid condensation occurs at the nozzle end.

The negative pressure is released during the standby mode and the negative pressure is released when the paste pattern is applied again, so that the raw material is discharged through the nozzle through proper positive pressure control.

For reference, since the residual pressure in the syringe is calculated to have a positive shape and the opposite pressure of the syringe control pressure has a type of 0 to -2 [kPa] negative pressure, the general vacuum module, CDA module, and pressure It is difficult to achieve negative pressure through a single pressure control module, such as a gauge gauge module. This is because the conventional pressure regulation module is difficult to control as a single sound pressure as a single module. Accordingly, embodiments of the present invention are configured to provide a negative pressure by combining a plurality of pressure regulation modules. For example, the pressure control device may be implemented to provide a desired negative pressure by constantly supplying (fixing) the vacuum pressure through a single vacuum module and adjusting and providing the CDA amount of a single CDA module.

On the other hand, after calculating the residual pressure in the syringe that changes according to the residual amount in the raw material, as shown in FIG. 4, providing the syringe adjustment pressure in the form of negative pressure, which is the opposite of the residual pressure, has a low viscosity It can be applied accurately to raw materials to prevent liquid buildup.

However, in the case of a raw material having a high viscosity, as shown in FIG. 5, raw material may be aggregated along the inner wall of the cylinder 110 due to the stress of the raw material. In this case, the pressure head (remaining height) in the cylinder of the detected raw material is not the actual pressure head.

In consideration of this point, the residual pressure value for each residual head height is supplied to the inside of the cylinder in the form of negative pressure without calculating the residual pressure value for each pressure head as shown in FIG. 4. A description with FIG. 6 is as follows.

6 is a flowchart illustrating a process of adjusting the pressure in the syringe after extracting the residual pressure for each pressure head from the table according to an embodiment of the present invention.

First, there is a process of detecting the pressure head (residual height) generated by the remaining amount of the raw material filled in the cylinder (S61).

After detecting the pressure head, the negative pressure to be applied to the pressure inside the syringe according to the detected pressure head is extracted (S63).

The negative pressure is extracted from the negative pressure table for each pressure head to which the negative pressure is assigned according to the pressure head of the raw material in the syringe (S63). The negative pressure table for each pressure head is a database table in which the negative pressure when no condensation occurs at the nozzle end is experimentally stored for each pressure head. Hereinafter, an example of the negative pressure table for each pressure head is described in [Table 1].

Pressure head [mm] Negative pressure [kPa] 10 -8 8 -6 6 -4 ...
...
... ...
...
...

As shown in [Table 1], when the pressure head according to the remaining amount of the raw material in the syringe is 10 [mm], no crushing occurs when the inside of the syringe is maintained at a negative pressure of -8 [kPa]. It can be seen. This is a value determined by a number of experiments, which is tabulated and managed.

Therefore, when the determined pressure head is 10 [mm], the negative pressure of -8 [kPa] assigned thereto is extracted from the negative pressure table for each pressure head, and is supplied to the inside of the syringe with the extracted negative pressure value ( S63) Condensation at the tip of the nozzle can be prevented.

On the other hand, if the identified pressure head is a value that does not exist in the negative pressure table for each pressure head, the negative pressure is calculated and used in consideration of the pressure head difference. That is, when the detected pressure head value does not exist in the negative pressure table for each pressure head, the two negative pressures assigned to the pressure heads adjacent to the detected pressure heads are extracted, and the median value of the two negative pressures is extracted. To be supplied into the syringe.

For example, if the identified pressure head is 9 [mm], the negative pressure assigned to the adjacent pressure head 10 [mm] is -8 [kPa] and the negative pressure assigned to the adjacent pressure head 8 [mm]. Control is performed to maintain the internal pressure of the syringe as a negative pressure value of -7 [kPa] which is a median value of -6 [kPa].

Although the present invention has been described with reference to the accompanying drawings and the preferred embodiments described above, the present invention is not limited thereto but is limited by the following claims. Accordingly, those skilled in the art will appreciate that various modifications and changes may be made thereto without departing from the spirit of the following claims.

100: dispenser 110: syringe
120: head unit 130: nozzle
200: pressure supply tank 300: pressure control device
400: pressure regulating valve

Claims (10)

A pressure regulating valve for adjusting a supply pressure into the syringe;
A pressure head sensor for detecting a pressure head of a syringe raw material;
A pressure control device that calculates a residual pressure corresponding to the detected pressure head, and controls the pressure regulating valve such that a negative pressure of the residual pressure is supplied into the syringe;
Liquid accumulation prevention device of the dispenser comprising a. delete The apparatus of claim 1, wherein the pressure regulating valve adjusts the amount of compressed air supplied while maintaining the vacuum pressure to supply a negative pressure to the inside of the syringe. Detecting the pressure head of the raw material in the syringe;
Calculating a residual pressure corresponding to the pressure head;
Supplying the residual pressure into the syringe in the form of a negative pressure;
Method of preventing liquid condensation comprising a. The method of claim 4, wherein the detecting of the pressure head comprises determining the total discharged amount calculated by multiplying the discharge time by the discharge time per hour of the raw material discharged through the nozzle of the syringe, and then using the total amount of the syringe. A method for preventing liquid formation of a dispenser that calculates a pressure head by subtracting it. The method of claim 4, wherein the calculating of the residual pressure
The correction constant value is a constant value indicating the specific gravity of the raw material when the specific gravity of water is '1'. The pressure value corresponding to 1 mm of water is 0.0001 [kgf / cm ² ], and the unit conversion constant value is the pressure value. It is 98.0665 which converts the unit of kgf / cm <^2> into kPa unit, and H is the pressure head of the raw material in a syringe,
Residual pressure [kPa] = Correction constant value × Pressure value [kgf / cm ² ] corresponding to 1 mm of water × Unit conversion constant value × H [mm] The liquid prevention method of the condensation computed. Detecting the pressure head of the raw material in the syringe;
Extracting a negative pressure assigned to the pressure head;
Supplying the extracted negative pressure into the syringe;
And extracting the negative pressure assigned to the pressure head, extracting the negative pressure assigned to the pressure head from the negative pressure table for each pressure head, in which a value of the negative pressure where liquid does not occur for each pressure head is set. How to prevent dripping of the dispenser. delete The method according to claim 7, wherein if the value of the detected pressure head is not present in the negative pressure table for each pressure head, two negative pressures are extracted by extracting two negative pressures assigned to the pressure heads adjacent to the detected pressure heads. A method for preventing liquid formation of the dispenser to be supplied to the inside of the syringe at an intermediate value of. The dispenser according to any one of claims 4 to 7, wherein the supply of the negative pressure into the syringe is performed during a waiting time after the application of the raw material is applied and before the next application. How to prevent clumping of blood.

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