KR20020088219A - Device for injecting liquid crystal material and method for manufacturing liquid crystal display using the same device - Google Patents

Abstract

PURPOSE: A liquid crystal injecting device and a fabricating method of an LCD by using the same are provided to control a cell gap for obtaining uniformity over the entire screen by dropping liquid crystal to a substrate by a target value or an amount in an available error range. CONSTITUTION: A liquid crystal display device includes a surface plate(100) to which a substrate(12) is loaded, a sensor(110) mounted to the surface plate for measuring a weight of the loaded substrate, a dispenser(27) for dropping liquid crystal, and a control part(120) for comparing the weight measured by the sensor with a set target value to control a dropping amount of the liquid crystal from the dispenser.

Description

TECHNICAL FIELD The liquid crystal injection device and the manufacturing method of the liquid crystal display device using the same {DEVICE FOR INJECTING LIQUID CRYSTAL MATERIAL AND METHOD FOR MANUFACTURING LIQUID CRYSTAL DISPLAY USING THE SAME DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal display device, and more particularly, to an apparatus capable of adjusting a dropping amount of a liquid crystal material in a liquid crystal cell process by a drop injection method, and a method for manufacturing a liquid crystal display device using the same.

In general, a manufacturing process of a liquid crystal display device includes an array substrate manufacturing process for forming a wiring pattern, a switching element (in an active matrix type), and the like on a glass substrate, and a liquid crystal material between an alignment process, a spacer arrangement, and an opposing glass substrate. It is classified into the liquid crystal cell process of encapsulation, and the module process of attaching a driver IC, mounting a back light, etc.

The liquid crystal cell process in the manufacturing process of the liquid crystal display device is a method of injecting a liquid crystal material, a drop injection method of dropping the liquid crystal material using the liquid crystal injection device and a vacuum injection method of injecting the liquid crystal material into the cell by the pressure difference and capillary phenomenon Etc. are used.

In the liquid crystal cell process by the double drop injection method, a frame is formed of an ultraviolet (UV) ultra-curable sealant around an array substrate on which a switching element such as a thin film transistor is formed, and then a drop injection device such as a dispenser is placed on the substrate surface in the frame. From the specified amount, a liquid crystal substance is added dropwise. Next, after dispersing the spacer on the color filter substrate facing the array substrate, the two substrates are aligned and bonded in vacuum. Next, the bonded substrate is irradiated with ultraviolet rays to cure the sealing material.

In the drop injection method, the thin film transistor array substrate and the color filter substrate are bonded in a vacuum, so that the cell gap is controlled by the amount of liquid crystal substance dropped in the cell. Therefore, in order to have a desired cell gap, an amount of liquid crystal material equal to the volume corresponding to the cell gap of the target value must be added dropwise.

However, it is not known whether the amount ejected from the dispenser is adjusted to the correct amount when the liquid crystal material is dropped. In addition, when bubbles are contained in the liquid crystal material, bubbles are ejected together by the volume of the liquid crystal material, so that the amount of the dropped liquid crystal material is smaller than the prescribed amount, resulting in a cell gap after bonding two substrates to be lower than the cell gap of the target value. The liquid crystal material containing such bubbles must proceed after defoaming, but it is impossible to completely remove the bubbles, and there is a need to deflate the liquid crystal material every time. If the liquid crystal material is completely degassed and then dropped, there is a hassle of checking each substrate whether the amount of the liquid crystal material emitted from the dispenser is accurately injected.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a method of uniformly adjusting the amount of liquid crystal material emitted from a liquid crystal injection device to uniformize a cell gap after bonding two substrates.

1A is a layout view of a substrate for a liquid crystal display device manufactured according to an embodiment of the present invention.

FIG. 1B is a cross-sectional view taken along the line П- П 'of FIG. 1A,

2 illustrates a liquid crystal injection device in which a liquid crystal material is dropped on a substrate for a liquid crystal display according to an exemplary embodiment of the present invention.

3 is a flow chart showing the operating principle of the liquid crystal injection device of FIG.

4A to 4C are diagrams illustrating a process of manufacturing a liquid crystal display substrate using the liquid crystal injection device of FIG. 2.

In order to solve this problem, a weight measuring sensor may be attached to a surface plate for loading a substrate, and the amount of liquid crystal material loaded in real time may be detected and measured by comparing the weight measurement value of the liquid crystal material from the sensor with the dropping target value of the liquid crystal material. Install the control unit.

According to the present invention, a liquid crystal injection device for dropping a liquid crystal material on a substrate for a liquid crystal display device is loaded on the surface plate for loading the substrate for the liquid crystal display device, a sensor for measuring the weight of the loaded substrate, the liquid crystal material dropping And a control unit for comparing the weight measured by the sensor with a predetermined value and adjusting the amount of dropping of the liquid crystal material from the dispenser.

At this time, the display unit for displaying the weight measurement from the sensor may be further provided.

In this case, if the measured value is larger than the target value, the controller outputs a defective display to the display unit. If the measured value is smaller than the target value, the controller may control the dispenser to further drop the insufficient liquid crystal material.

In this case, the dispenser and the surface plate may be moved relative to each other.

Then, the liquid crystal injection apparatus and the method of manufacturing the liquid crystal display device using the same according to the embodiments of the present invention will be described in detail with reference to the accompanying drawings so that a person skilled in the art can easily practice the present invention. do.

First, a schematic structure of a liquid crystal display substrate manufactured according to an exemplary embodiment of the present invention will be described with reference to FIGS. 1A and 1B.

FIG. 1A is a layout view of a portion of an active matrix liquid crystal display substrate using a thin film transistor as a switching element, as viewed from the color filter substrate side, and FIG. 1B is a partial cross-sectional view taken along the line FF ′ of FIG. 1A.

On the array substrate 12 side of the liquid crystal display substrate 10, a plurality of pixel regions 26 arranged in a matrix are formed, and the plurality of pixel regions 26 form a display region 24 of an image. Although not shown in detail, thin film transistors (not shown) are formed in each pixel region 26. In this case, the gate electrode of the thin film transistor is connected to a gate line (not shown), and the drain electrode is connected to a data line (not shown). In addition, the source electrode of the thin film transistor is connected to a pixel electrode (not shown) formed in the pixel region 26. The plurality of data lines and the gate lines are connected to the driving circuit (not shown) through the terminal portion 14 formed on the outer periphery of the array substrate 12.

The color filter substrate 16 is provided with a color filter (not shown) of R (red), G (green), and B (blue) together with a common electrode (not shown). In addition, black matrixes 20 and 22 having a light shielding function are formed in the color filter substrate 16. The display unit black matrix 20 is provided to partition the plurality of pixel regions 26 in the display region 24 to prevent leakage of light at the boundary of the pixel region 26 and further includes a thin film transistor (not shown). Light shielding is used to prevent the occurrence of light leakage current. In addition, the edge part black matrix 22 is provided in order to shield unnecessary light outside the display area 24.

The color filter substrate 16 is formed smaller than the array substrate 12 by the area of the terminal portion 14, and is provided to face the array substrate 12 by sealing the liquid crystal material in a predetermined cell gap. At this time, the cell gap is kept constant and uniform by using a spacer (not shown) of a specific size. However, if the distribution density of the sealing pattern 18 or the liquid crystal material 28 on the substrate is not constant, the cell gap becomes inconsistent, resulting in non-uniform screens throughout the screen of the liquid crystal display. Therefore, it is desirable to make the sealing pattern and the distribution density of the liquid crystal uniform.

The array substrate 12 and the color filter substrate 16 are bonded by an ultraviolet curable sealant 18, and the region surrounded by the ultraviolet curable sealant 18 between the two substrates 12 and 16 is in a region. The liquid crystal material 28 is sealed. Here, the ultraviolet curable sealant 18 is an uncured sealant using a sealant 18 that can ensure non-mixability with the liquid crystal material 28 filled between the two substrates 12 and 16. 18 and the liquid crystal material 28 are contacted to prevent contamination.

In the layout of the substrate for the liquid crystal display device, a process equipment and a principle of operation of the equipment to have a uniform distribution density of the liquid crystal material, which is one of the methods of securing the uniformity and the reliability of the cell gap maintaining the distance between the two substrates, are also illustrated. It demonstrates with reference to 2 and FIG.

FIG. 2 illustrates a liquid crystal injection device for dropping a liquid crystal material on a substrate in a liquid crystal cell process by a drop injection method, and FIG. 3 is a flowchart illustrating an operating principle of the liquid crystal injection device of FIG. 2.

As shown in FIG. 2, the liquid crystal injection device includes a substrate 12, a dispenser 27, a surface plate 100, a sensor 110, a control unit 120, and a detection display unit 130.

The sensor 110 is installed on the surface plate 100 for loading the substrate 12 to measure the weight of the liquid crystal material dropped from the dispenser 27. Here, the surface plate 100 and the dispenser 27 can move relative to each other. The detection display unit 130 displays a drop amount of the liquid crystal material measured by the sensor 110 in numerical value so that the presenter can know. The controller 120 compares the weight measurement value of the liquid crystal material measured by the sensor 110 with the dropping target value of the liquid crystal material to adjust the amount of dropping of the liquid crystal material. At this time, when the difference between the weight measurement value and the dropping target value is 0 or within a predetermined error range, the dropping of the liquid crystal material is stopped.

Here, the measurement of the amount of liquid crystal substance using the sensor 110 includes a method of measuring volume and a method of measuring weight. Among these two methods, in order to accurately measure the amount of liquid crystal when bubbles are included in the liquid crystal material, a method of measuring weight is easier and more accurate than a method of measuring volume. And since liquid crystals have different specific gravity, it is possible to convert the amount of liquid crystal corresponding to a desired volume into weight using specific gravity.

The operating principle of the device for controlling the amount of such liquid crystal substance is described.

As shown in FIG. 3, first, an initial setting value is input (step 200). That is, the initial weight of the liquid crystal material ( ), The number of test drops ), Total loads ( ), And the target value ( ). Here, the initial weight of the liquid crystal material ( ) And the target value of the liquid crystal dropping amount ( ) Can be obtained as

= Specific gravity of liquid crystal material Active area Cell gap thickness of the target value ( )

The dispenser 27 then drops the liquid crystal material 28 onto the substrate 12 surface (step 210). At this time, the weight sensor 110 mounted in the surface plate 100 on which the substrate 12 is loaded measures the weight of the substrate 12 before the liquid crystal material is loaded. Next, the liquid crystal dropping amount is measured (step 220). That is, the sensor 110 measures the weight after the liquid crystal material has been repeatedly deposited on the substrate 12, and the value measured by the sensor 110 is displayed by the detection display unit 130 as a numerical value so that the presenter can check. . At this time, the weight of the liquid crystal material ( ) Is obtained by subtracting the weight of the substrate 12 before the liquid crystal material is dropped from the weight of the substrate 12 after the liquid crystal material is dropped.

Next, the set value and the measured value are compared (step 230). That is, the control unit 120 mounted on the dispenser 27 controls the target amount of liquid crystal material ( Weight of liquid crystal material ( Value obtained by subtracting Value It is determined whether is in a specified error range that satisfies Equation 3 below.

The 0.05 value here is a factor that can change depending on the process.

When Equation 3 is satisfied, the dropping process of the liquid crystal material is finished, and the two substrates are aligned and bonded (step 240).

if, Does not satisfy Equation 3 It is determined whether has a value greater than zero (step 250). That is, the liquid crystal material is the target value ( ) Or less than It is to judge whether it was loaded more than).

If the liquid crystal material contains bubbles, the target value ( Less than), i.e. If the value of is greater than 0, the control unit 120 The additional dropping pressure and the additional dropping time at which as many liquid crystal substances can be loaded are calculated.

Next, the controller 120 controls feedback of the dispenser 27 to drop the liquid crystal material with the additional dropping pressure and the additional dropping time (step 260).

On the other hand, the measured value of the liquid crystal substance dropped on the substrate 12 ( ) Is your target value ( ), That is, If is less than 0, the dispenser 27 is considered to have a problem in the reproducibility or precision of the dispenser 27 (step 270). At this time, the detection display unit 130 indicates that the dispenser 27 is defective.

This method can feed the dispenser 27 by detecting the weight in real time each time by the sensor 110 whenever the liquid crystal material is dropped, or measure the weight by the sensor 110 after all the dropping of the liquid crystal material is finished. The dispenser 27 can then be fed back.

As described above, the amount of the liquid crystal material 28 dropped may be adjusted by feeding back the weight value measured by the sensor 110 and comparing the numerical amount with the controller 120 so that the amount of the liquid crystal material dropped may fall within a target value or an error range. It can be adjusted accurately. In addition, even if the liquid crystal material 28 is not completely defoamed, the weight can be measured for each substrate, so that the correct amount of liquid crystal can be dropped. In addition, when there is a problem in the reproducibility or precision of the dispenser 27, the dispenser 27 can be inspected at any time. Therefore, the accurate dropping amount of the liquid crystal material 28 can adjust the cell gap after bonding the two substrates 12 and 16 to improve the uniformity and reliability of the entire screen.

Next, a method of manufacturing the liquid crystal display according to the exemplary embodiment of the present invention by applying the above-described apparatus for adjusting the dropping amount of the liquid crystal material will be described with reference to FIGS. 3A to 3C.

Since the manufacturing method of the liquid crystal display device relates to a liquid crystal cell process including applying a sealing material to the substrate, which can ensure non-mixability with the liquid crystal material, the wiring pattern and the switching element (active matrix type) And the module process for attaching the driver IC, attaching the back light, etc. are the same as in the prior art, and the description thereof will be omitted.

As shown in FIG. 3A, the spacer 30 is spread on the color filter substrate 16 by a wet method or a dry method from a spacer spreading device (not shown). The wet method is a method in which a spacer is mixed with a solvent and sprayed, and the dry method is a method in which air or N2 gas is used for spraying. A sealing pattern 18 of ultraviolet (UV) curable material is formed in a frame shape around the array substrate 12 on which switching elements such as thin film transistors are formed. Here, the substrate scattering the spacer 30 or forming the sealing pattern 18 may be changed, and the spacer 30 and the sealing pattern 18 may be formed on one substrate.

Next, the liquid crystal material 28 is dropped from the dispenser 27 on the substrate surface in the frame using the above-described liquid crystal injection device. In this case, the liquid crystal material 28 is uniformly distributed on the substrate 12 even if the liquid crystal material 28 is not completely defoamed.

Next, as shown in FIG. 3B, the color filter substrate 16 in which the spacers are scattered is positioned in the vacuum chamber and bonded to the array substrate 12 on which the sealing pattern 18 is formed by a pressing process. Here, the liquid crystal material 28, which has not been defoamed in the previous step, is defoamed by adjusting the time of stay in the vacuum chamber. Next, when the bonded substrate is restored to the atmosphere, the liquid crystal material 28 between the bonded array substrate 12 and the color filter substrate 16 diffuses by atmospheric pressure.

Next, as shown in FIG. 3C, the ultraviolet ray light 34 is irradiated and cured along the arrow 36 to the sealing pattern 18 while the ultraviolet ray light source 32 is moved.

Although not shown, the liquid crystal display substrate having been subjected to the above-described process is cut and separated in units of substrates. After inspecting each separated board | substrate and selecting only good goods, a polarizing plate is attached and a liquid crystal cell process is complete | finished.

In the liquid crystal cell process by the drop injection method according to the embodiment of the present invention, when the liquid crystal material 28 is dropped, a predetermined amount of the liquid crystal material 28 may be dropped by using the liquid crystal injection device of the liquid crystal material 28. The cell gap after bonding two board | substrates 12 and 16 can be made uniform.

As described above, according to the present invention, a weighing sensor is attached to the base plate on which the substrate is loaded to measure a loading amount of the liquid crystal material in real time. The liquid crystal material may be adjusted and dropped by the controller so as to be within the same target value or error range. Therefore, the cell gap can be adjusted to improve uniformity over the entire screen and to ensure reliability.

Claims (6)

In the liquid crystal injection device in which a liquid crystal substance is dropped on a substrate for a liquid crystal display device, A surface plate for loading the substrate for the liquid crystal display device; A sensor installed on the surface plate and measuring the weight of the loaded substrate, A dispenser for dropping the liquid crystal material, Control unit for adjusting the amount of liquid crystal material dropping from the dispenser by comparing the weight measured by the sensor with a predetermined target value Liquid crystal injection apparatus comprising a. In claim 1, And a display unit for displaying the weight measurement from the sensor. The method of claim 1 or 2, And the control unit outputs a defective display to the display unit when the measured value is greater than the target value, and controls the dispenser to further drop the insufficient liquid crystal material when the measured value is smaller than the target value. In claim 1, And the dispenser and the surface plate can move relative to each other. Applying a sealant on top of either substrate, Dropping a liquid crystal material on one of the two substrates; In the manufacturing method of the liquid crystal display device comprising the step of aligning and bonding the two substrates, The dropping of the liquid crystal material may further include controlling the amount of liquid crystal dropped in real time by measuring the weight of the dropped liquid crystal material. In claim 5, The controlling of the liquid crystal amount may include controlling feedback of the liquid crystal material to be added dropwise if the measured value of the liquid crystal material dropped is smaller than a predetermined target value.