KR19990080466A - Liquid Crystal Display and Manufacturing Method Thereof - Google Patents

Abstract

A thin film transistor is formed on the transparent lower insulating substrate, and an alignment film is coated thereon. A color filter is formed on the upper insulating substrate corresponding to the lower insulating substrate, and an ITO layer serving as a common electrode is formed on the entire surface. A black matrix is formed on the color filter, and the alignment film is coated on the entire surface. At this time, the black matrix has a height of 0.5 to 5.0 µm and is formed in contact with the surface of the thin film transistor portion. In addition, the black matrix is composed of an organic polymer photosensitive agent having a strength of 1.0kg / cm ² or more. Liquid crystal is injected between the upper and lower substrates.

As described above, in the liquid crystal display device requiring a thin cell spacing, the cell spacing may be uniformly and thinly formed by adjusting the height of the black matrix to form and maintain the cell spacing instead of the spacer.

Description

Liquid Crystal Display and Manufacturing Method Thereof

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device and a method for manufacturing the same, and more particularly, to a thin film transistor liquid crystal display device having a thin and uniform cell spacing and a method for manufacturing the same.

In general, a liquid crystal display device using a thin film transistor as a switching element performs a display function of controlling light transmission and blocking by changing an arrangement direction of liquid crystal molecules positioned between two substrates.

Next, a liquid crystal display according to the related art will be described with reference to the drawings.

1 is a cross-sectional view of a general liquid crystal display, and a structure of a liquid crystal display according to the prior art will be described with reference to FIG. 1.

The thin film transistor 2, the wiring electrode, and the like are formed on the transparent lower insulating substrate 1, and the color filter 5, the black matrix 6, and the like are formed on the upper substrate 4 corresponding to the lower substrate. The common electrode 7 is formed thereon. Alignment films 3 and 8 are applied to the upper substrate 4 and the lower substrate 1 to align the liquid crystals 10, and the two substrates 1 and 4 are bonded to each other at regular intervals. And are fixed to each other by the same, and a spacer 9 for maintaining a gap between the liquid crystal 10 and the two substrates is injected therebetween.

The manufacturing method of the liquid crystal display device having the above structure is as follows.

First, a thin film transistor substrate is manufactured by a conventional method. Next, after forming a color filter, a black matrix, etc. on a transparent insulation board | substrate, a common electrode and an orientation film are formed in order on it. Next, an adhesive for joining the above two substrates is printed on one substrate, and on another substrate, a spacer for distributing a constant gap between the two substrates is distributed. Next, after the two substrates are assembled to form a cell, a liquid crystal is injected into the cell by using a vacuum injection method.

On the other hand, in the liquid crystal display device using the TN mode, the response speed is proportional to the square of the cell spacing, so it is preferable to have a cell spacing of 3 μm or less, and to use an anti-ferroelectric liquid crystal having a pitch. In the liquid crystal display device, a cell spacing of 2 ± 0.5 μm is required in order to suppress the spiral structure and orient it horizontally.

However, in the liquid crystal display device according to the prior art, a typical cell spacing is about 5 to 10 μm, and among the spacers used to maintain the cell spacing, a size of about 3 μm is currently available as the smallest plastic or glass fiber spacer. There is a situation.

In addition, in the manufacturing method of the liquid crystal display device as in the prior art, when the spacers are scattered on the substrate, the spacers are likely to aggregate into one place, and even if the spacers are uniformly distributed, the spacers may be pushed and moved during the liquid crystal injection, resulting in uniform It is difficult to get cell spacing.

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display device having a thin and uniform cell spacing and a method of manufacturing the same.

1 is a cross-sectional view of a liquid crystal display device according to the prior art,

2 is a cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention.

3 is a plan view illustrating a position where cell spacing is measured in a liquid crystal display according to an exemplary embodiment of the present invention.

In order to solve this problem, the present invention forms a color filter on the upper substrate, and then deposits an ITO layer for the common electrode thereon. Form a black matrix on it. In this case, the black matrix is preferably formed of an organic polymer having a strength of 1.0 kg / cm ² or more, and may be formed at a height of 0.5 to 5.0 μm, that is, when a thin cell gap is to be formed, The height can be made low. In addition, since the black matrix is in contact with the thin film transistor and forms a cell gap, it is preferable to determine the height of the black matrix in consideration of the step difference of the thin film transistor formed on the lower substrate. After assembling the upper substrate thus formed and the lower substrate manufactured by a conventional method, the liquid crystal is injected between the two substrates.

As such, the cell gap may be uniformly formed and maintained using the black matrix without using the spacer, and the thin cell gap may be formed by adjusting the height of the black matrix.

Then, embodiments of the present invention will be described in detail with reference to the drawings so that those skilled in the art can easily implement the present invention.

FIG. 2 is a cross-sectional view of a liquid crystal display according to an exemplary embodiment of the present invention. First, a structure of a liquid crystal display according to an exemplary embodiment of the present invention will be described with reference to FIG. 2.

The gate electrode 11 is formed on the transparent lower insulating substrate 20, and the gate insulating film 22 is formed thereon. The semiconductor layer 23 is formed on the gate insulating film 22 at the position corresponding to the gate electrode 21, and the source and drain electrodes 24 and 25 are separated on both sides of the gate electrode 21. It is. A passivation film 26 having a contact hole is formed thereon, and a pixel electrode 27 is formed thereon connected to the drain electrode 25 through the contact hole. The alignment film 28 is formed over the entire surface.

The color filter 30 is formed on the transparent upper insulating substrate 29 corresponding to the lower substrate 20, and the ITO layer 31, which is a common electrode, is formed thereon. The black matrix 32 that prevents light leakage between the color filters 30 is formed of an acrylic polymer or a BCB (benzo cyclobutane) polymer, which is an organic material having an intensity of 1.0 kg / cm ² or more, and is 0.5 to It may have a height of 5.0 μm, more specifically 1.0 to 2.0 μm. The alignment film 33 which is a polyimide-type polymer is apply | coated on it. At this time, the alignment film 33 is rubbed.

In the above structure, the alignment layer 33 formed on the black matrix 32 is in contact with the alignment layer 28 of the thin film transistor portion, and a ferroelectric liquid crystal 34 is injected between the two substrates. At this time, the liquid crystal may be other liquid crystal in addition to the ferroelectric liquid crystal.

In the liquid crystal display having such a structure, by forming a black matrix serving as a spacer on the common electrode of the color filter substrate by adjusting the height, a thin cell gap can be maintained uniformly without using a separate spacer, and thus the antiferroelectric liquid crystal The pitch can be suppressed and oriented.

Then, the manufacturing method of the liquid crystal display device which has the above structure is demonstrated.

First, a gate wiring including a gate electrode or the like is formed on a transparent lower insulating substrate, a gate insulating film is stacked thereon, and then a semiconductor layer including an amorphous silicon layer and a doped amorphous silicon layer is sequentially stacked, and then a semiconductor layer. Pattern. A metal layer is formed thereon, and then patterned to form a source electrode, a drain electrode, and a data line separated on both sides with respect to the gate electrode. Subsequently, the doped amorphous silicon layer that is not covered by the source and drain electrodes is etched, the passivation layer is stacked, and the passivation layer is etched to form a contact hole for exposing a part of the drain electrode. Next, after the ITO layer is formed, the pixel electrode is patterned to form a pixel electrode connected to the drain electrode through the contact hole. The alignment film is applied thereon using a polyimide polymer.

Next, red, green, and blue color filters are patterned and formed on the transparent upper insulating substrate, and then an ITO layer is stacked thereon to form a common electrode. The black matrix is formed thereon so as to be positioned between the color filters, wherein the black matrix is formed of an organic polymer having low reflectivity, and the height of the thin film transistor which forms a cell gap together with the black matrix when assembling the upper and lower substrates. In consideration of this, to form a height of 0.5 ~ 5.0μm. That is, since the step of the thin film transistor is 1 μm or less, the step is formed at a height excluding the step of the thin film transistor from the cell gap to be formed. Next, the alignment film of a polyimide system is apply | coated on it. Next, the formed upper and lower substrates are assembled so that the black matrix portion is in contact with the thin film transistor portion of the lower substrate and assembled using a gap agent that supports the cell gap, and then liquid crystal is injected between the two substrates.

As such, after forming the common electrode in the upper substrate manufacturing process so that the black matrix can be used instead of the spacer in the liquid crystal display, a black matrix is formed thereon, and the height of the black matrix is adjusted to decrease the cell gap. Can be formed.

FIG. 2 is a plan view showing a position at which cell spacing is measured in the liquid crystal display manufactured by the above method.

After manufacturing three liquid crystal display devices using the same 1.5μm black matrix, the cell spacing at each corner portion (A, B, C, D) and the center portion (E) of the panel was measured. Same as

1 time Episode 2 3rd time Average A 1.145 1.147 1.140 1.144 B 1.146 1.148 1.147 1.147 C 1.135 1.136 1.141 1.137 D 1.142 1.145 1.143 1.143 E 1.136 1.135 1.136 1.136

As can be seen from Table 1, the cell spacing in each part of the liquid crystal display device manufactured using the 1.5 m black matrix was measured within a good range of 1.14 ± 0.01 m.

As mentioned above, by forming a black matrix on the common electrode of the color filter substrate so that the black matrix can be used instead of the spacer, by adjusting and forming the height of the black matrix, it is possible to maintain a thin cell gap evenly without using the spacer. In addition, it is possible not only to effectively implement a mode using an antiferroelectric liquid crystal, but also to obtain a fast response speed when applied to a liquid crystal display using a TN mode.

Claims (12)

A thin film transistor formed on the transparent lower insulating substrate, A first alignment layer coated on the thin film transistor, An upper insulating substrate corresponding to the lower insulating substrate, A color filter formed on the upper insulating substrate, A common electrode formed on the color filter, A black matrix positioned between the color filters and formed on the common electrode; A second alignment layer coated on the black matrix; Including; And a second alignment layer on the black matrix and the second alignment layer on the thin film transistor. In claim 1, The black matrix is a liquid crystal display device made of an organic polymer. In claim 2, The organic polymer is an acrylic or BCB-based liquid crystal display device. In claim 3, The height of the black matrix is 0.5 to 5.0μm liquid crystal display device. In claim 4, The black matrix has a strength of 1.0 kg / cm ² or more. In claim 5, And the liquid crystal is an antiferroelectric material. In claim 6, The alignment film is a polyimide-based liquid crystal display device. In claim 7, A liquid crystal display device in which liquid crystal is injected between the upper and lower substrates. Applying a first alignment layer to the first substrate, Forming a color filter on the second substrate, Forming a transparent conductive film on the color filter, Forming a black matrix on the transparent conductive film, Forming a second alignment layer on the black matrix, Assembling the first substrate and the second substrate using the black matrix as a gap agent. Method of manufacturing a liquid crystal display comprising a. In claim 9, And the black matrix is formed of an organic polymer. In claim 10, The black matrix is a manufacturing method of a liquid crystal display device to form a height of 0.5 to 5.0μm. In claim 11, The manufacturing method of the liquid crystal display device which uses a polyimide-type polymer as said oriented film.