KR20030055366A - Method Of Fabricating Liquid Crystal Display Device - Google Patents

Abstract

PURPOSE: A producing method of an LCD(Liquid Crystal Display Device) is provided to have a spacer of a wanted shape. CONSTITUTION: A spacer material on a nozzle of an ink-jet head is soft-baked. The soft-backed spacer material is loaded on a substrate. A spacer(58) is formed on the substrate by burning the spacer material. Thereby, the spacer is formed in the forming position exactly. Moreover, the cost is reduced and the declination is eliminated.

Description

Method of manufacturing liquid crystal display device {Method Of Fabricating Liquid Crystal Display Device}

The present invention relates to a liquid crystal display device, and more particularly to a method for manufacturing a liquid crystal display device having a spacer of a desired form.

In general, a liquid crystal display (LCD) displays an image by adjusting the light transmittance of the liquid crystal using an electric field. To this end, the liquid crystal display device includes a liquid crystal panel in which liquid crystal cells are arranged in a matrix, and a driving circuit for driving the liquid crystal panel. The liquid crystal panel includes pixel electrodes for applying an electric field to each of the liquid crystal cells and a reference electrode, that is, a common electrode. In general, the pixel electrode is formed for each liquid crystal cell on the lower substrate, while the common electrode is integrally formed on the front surface of the upper substrate. Each of the pixel electrodes is connected to a thin film transistor (hereinafter referred to as "TFT") used as a switching element. The liquid crystal cell is driven along with the common electrode in accordance with the data signal supplied through the TFT.

Referring to FIG. 1, a conventional LCD includes a black matrix 32, a color filter 30, a common electrode 28, a column spacer 26, and an upper alignment layer 34 that are sequentially formed on an upper substrate 11. Liquid crystal injected into the inner space provided by the upper plate, the lower plate consisting of the TFT and the pixel electrode 22 and the lower alignment layer 24 formed on the lower substrate 1, the upper plate and the lower plate and the column spacer 26 40.

In the upper plate, the black matrix 32 is formed in a matrix form on the upper substrate 11 to divide the surface of the upper substrate 11 into a plurality of cell regions in which the color filters 30 are to be formed, as well as optical interference between adjacent cells. It will act to prevent. The color filters 30 of red, green, and blue primary colors are sequentially formed on the upper substrate 11 on which the black matrix 32 is formed. The common electrode 28 to which the ground potential is supplied is formed on the upper substrate 11 on which the black matrix 32 and the color filter 30 are formed. The column spacer 26 is formed on the common electrode 28 to correspond to the black matrix 32. The column spacer 26 serves to provide a space for injecting the liquid crystal 40 between the upper and lower plates. An upper alignment layer 34 is formed to cover the column spacer 26 and the common electrode 28.

The TFT for switching the driving of the liquid crystal cell on the lower plate includes the gate electrode 6 connected to the gate line (not shown), the source electrode 8 connected to the data line (not shown), and the pixel electrode 22 through the contact hole. And a drain electrode 10 connected to it. Further, the TFT is formed by the gate insulating film 12 for insulating the gate electrode 6, the source electrode 8, and the drain electrode 10, and the source electrode 8 by the gate voltage supplied to the gate electrode 6; The semiconductor layers 14 and 16 are further provided to form a conductive channel between the drain electrodes 10. This TFT selectively supplies the data signal from the data line to the pixel electrode 22 in response to the gate signal from the gate line. The pixel electrode 22 is formed of a transparent conductive material having a high light transmittance and positioned in a cell region divided by a data line and a gate line. The pixel electrode 22 is formed on the passivation layer 18 coated on the entire surface of the lower substrate 1, and is electrically connected to the drain electrode 10 through a contact hole formed in the passivation layer 18. After applying the lower alignment layer 24 on the lower substrate 1 on which the pixel electrode 22 is formed, a rubbing process is performed to complete the lower plate.

Finally, the liquid crystal display device is completed by injecting and encapsulating the liquid crystal 40 into the liquid crystal space provided by the column spacer 26 after attaching the upper and lower plates separately prepared as described above.

A manufacturing process of the upper plate having such a configuration will be described with reference to FIGS. 2A to 2G.

First, a black matrix 32 is formed as shown in FIG. 2A by depositing an opaque metal such as opaque resin or chromium on the upper substrate 11 and patterning the same. By absorbing the white light source on the upper substrate 11 on which the black matrix 32 is formed to transmit only a light having a specific wavelength (red, green, or blue), a material is patterned and then patterned, as shown in FIG. 2B. Color filters 30A, 30B, 30C are formed. The common electrode 28 is formed as shown in FIG. 2C by depositing a transparent metal layer on the upper substrate 11 on which the black matrix 32 and the color filters 30A, 30B, and 30C are formed.

Referring to FIG. 2D, a material mixed with a solvent, a binder, a monomer, and a photoinitiator is printed and dried on the upper substrate 11 on which the common electrode 28 is formed. The paste 26a in which the photoinitiator is mixed is formed.

Referring to FIG. 2E, ultraviolet light is selectively irradiated onto the paste 26a by using a photomask 38 having a blocking portion 38a and a transmitting portion 38b on the upper substrate 11 having the paste 26a formed thereon. Exposure. At this time, when light is irradiated through the photomask 38, photoinitiators are decomposed to form radicals. This radical polymerizes the bonds of monomers distributed between the binders to maintain the viscosity of the exposed paste 26a.

Referring to Fig. 2F, paste 26a is developed with a developer. At this time, the paste 26a is left without the unexposed paste and the exposed paste. When the remaining paste 26a is fired, a column spacer 26 having a length of about 4.5 mu m is formed.

Referring to FIG. 2G, the polyimide is entirely coated on the upper substrate 11 on which the column spacer 26 is formed to form the upper alignment layer 34.

The column spacer 26 of the conventional liquid crystal display device occupies 2% of the area of the upper substrate 11. The column spacer 26 is completely printed on the upper substrate 11 on which the color filters 30A, 30B, and 30C are formed to undergo exposure, development, and baking processes. Accordingly, there is a problem in that loss of material, loss of time, and the like occur. In addition, when the upper alignment layer 34 is formed on the transparent electrode 28, there is a problem in that disclination occurs.

In order to solve this problem, a spacer is formed using an inkjet. However, a spacer formed by using an inkjet is difficult to obtain a desired shape when dropping the spacer material, there is a problem that the accuracy of the spacer formation position is inferior.

Accordingly, an object of the present invention is to provide a method of manufacturing a liquid crystal display device having a spacer of a desired shape.

1 is a cross-sectional view showing a conventional liquid crystal display device.

2A to 2G are sectional views showing the manufacturing process of the upper plate shown in FIG.

3A to 3H are cross-sectional views illustrating a manufacturing process of a top plate of a liquid crystal display device according to the present invention.

<Explanation of symbols for main parts of drawing>

11,41: upper substrate 26, 58: spacer

28,58: common electrode 30,60: color filter

32,62: Black matrix 34,64: Upper alignment layer

In order to achieve the above object, the manufacturing method of the liquid crystal display device according to the present invention comprises the steps of soft-baking the spacer material formed on the inkjet head nozzle, the step of seating the soft-baked spacer material on the substrate, Firing to form spacers on the substrate.

The soft baking is characterized in that it is carried out at a temperature of 200 ℃ or less.

The firing temperature is characterized in that less than 200 ~ 250 ℃.

The diameter of the nozzle is characterized in that 5 ~ 50㎛.

The diameter of the spacer material formed on the nozzle is characterized in that 10 ~ 50㎛.

The method of manufacturing the liquid crystal display device includes forming a black matrix on a substrate, forming a color filter on the substrate, forming a common electrode on the color filter, and forming an alignment layer on the common electrode. Characterized in that it comprises a step.

The inkjet head nozzle may be aligned to a region corresponding to the black matrix.

Other objects and features of the present invention in addition to the above objects will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 3A to 3H.

3A to 3H are cross-sectional views illustrating a spacer forming method according to the present invention.

Referring to FIG. 3A, an opaque metal layer is deposited on the upper substrate 41. The opaque metal layer is made of opaque resin or chromium (Cr). Subsequently, the black matrix 62 is formed by patterning the opaque metal layer by a photolithography process including an etching process.

Referring to FIG. 3B, a color of three primary colors is formed by applying a material that absorbs a white light source and transmits only a light having a specific wavelength (red, green, or blue) on the upper substrate 41 on which the black matrix 62 is formed. Filters 60A, 60B, 60C are formed.

Referring to FIG. 3C, the transparent electrode 58 is formed by depositing a transparent metal layer on the upper substrate 41 on which the black matrix 62 and the color filters 60A, 60B, and 60C are formed. The transparent electrode 58 is an indium-tin-oxide, indium-zinc-oxide, or indium-tin-zinc-oxide, which is a transparent metal layer. ) And the like.

Referring to FIG. 3D, an upper alignment layer 64 is formed on the upper substrate 41 on which the transparent electrode 58 is formed. The upper alignment film 64 is formed by applying a polyimide to perform a rubbing process.

Referring to FIG. 3E, an inkjet 52 is aligned on an area corresponding to the black matrix 62 of the upper substrate 41 on which the upper alignment layer 64 is formed. On the nozzle 54 of the inkjet head 52, a spacer material 56 having a predetermined viscosity and not dropping is formed. At this time, the spacer material 56 is softbaked at a temperature of 200 ° C. or less to remove the solvent contained in the spacer material 56.

Here, the nozzle 54 has a built-in elastic ball or hydraulic device to adjust the amount of the spacer material 56 that is released in one contact. The outlet of this nozzle 54 is formed to have a diameter of 5㎛ ~ 50㎛. The spacer material 56 which is suspended on the nozzle 54 is formed to have a diameter of 10 μm to 50 μm.

Referring to FIG. 3F, the inkjet head 52 is lowered toward the upper substrate 41 on which the upper alignment layer 64 is formed so that the spacer material 56 from which the solvent is removed is in contact with the upper alignment layer 64. The spacer material 56 is soft baked so that the height, diameter, shape, etc. of the spacer can be formed in a desired shape, and the position can be accurately aligned.

Referring to FIG. 3G, the inkjet head 52 is raised after forming the spacer material 56 to contact the upper alignment layer 64. At this time, the inkjet head 52 is raised to more effectively control the height of the spacer material 56.

Referring to FIG. 3H, the spacer material 56 formed on the upper alignment layer 64 is fired at a temperature relatively higher than the soft baking temperature to form the spacer 58. The firing temperature is preferably 200 to 250 ° C.

As described above, the manufacturing method of the liquid crystal display device according to the present invention soft-bakes the spacer material before dropping the spacer material. By contacting the substrate with the inkjet head nozzle on which the soft-baked spacer material is formed, a spacer having a shape such as a desired height and width is formed, and is accurately formed at the spacer formation position.

In addition, the manufacturing process is simpler than that of the column spacer, thereby reducing the cost. In addition, since it is formed on the rubbed alignment layer, the disclination phenomenon can be eliminated.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (7)

Softbaking the spacer material formed on the inkjet head nozzle; Depositing the soft baked spacer material on a substrate; Calcining the spacer material to form a spacer on the substrate. The method of claim 1, The soft baking is carried out at a temperature of less than 200 ℃ manufacturing method of the liquid crystal display device. The method of claim 1, The firing temperature is a manufacturing method of the liquid crystal display device, characterized in that less than 200 ~ 250 ℃. The method of claim 1, The nozzle has a diameter of 5 ~ 50㎛ manufacturing method of the liquid crystal display device. The method of claim 1, The diameter of the spacer material formed on the nozzle is a method of manufacturing a liquid crystal display device, characterized in that 10 ~ 50㎛. The method of claim 1, Forming a black matrix on the substrate; Forming a color filter on the substrate; Forming a common electrode on the color filter; And forming an alignment layer on the common electrode. The method of claim 6, And the ink jet head nozzle is aligned to a region corresponding to the black matrix.