KR20070002753A - Transflective type liquid crystal display device and method for fabricating the same - Google Patents

Abstract

A transflective LCD and a manufacturing method thereof are provided to implement a single cell-gap mode and thus a dual cell gap by forming a planarization layer at a transmissive area and adding a voltage control layer to a reflective area when an embossed portion is formed. A gate line(112) and a data line(115) vertically intersect each other on a first substrate to define a pixel region including a reflective area and a transmissive area. A thin film transistor(TFT) is formed at an intersection of the gate line and the data line. A passivation layer is formed on an entire surface including the thin film transistor. A first transmissive electrode(150) is formed at the transmissive area of the pixel region. A reflective electrode(124) is formed at the reflective area of the pixel region. A voltage control layer is formed at the reflective area of the pixel region. A second transmissive electrode(117) is insulated from the first transmissive electrode and the reflective electrode, and includes a plurality of slits to form an in-plane electric field between the first transmissive electrode and the reflective electrode. A liquid crystal layer faces and is bonded with the first substrate, and has a uniform cell gap with the second substrate.

Description

Transflective Type Liquid Crystal Display Device And Method For Fabricating The Same}

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

2 is a pixel plan view of a transflective liquid crystal display device according to a first embodiment of the present invention.

3 is a cross-sectional view taken along line II ′ of FIG. 2.

4A to 4F are cross-sectional views of a transflective liquid crystal display device according to a first embodiment of the present invention.

5 is a pixel plan view of a transflective liquid crystal display device according to a second embodiment of the present invention.

6 is a cross-sectional view taken along line II-II ′ of FIG. 5.

7A to 7E are cross-sectional views of a transflective liquid crystal display device according to a second embodiment of the present invention.

* Explanation of symbols on the main parts of the drawings

111: TFT array substrate 112: gate wiring

115: data wiring 116: voltage regulation layer

117: second transmission electrode 118: interlayer insulating film

124: reflective electrode 150: first transmission electrode

160: uneven pattern 161: planarization layer

121: color filter array substrate 131: liquid crystal layer

The present invention relates to a liquid crystal display device, and more particularly, to a semi-transmissive liquid crystal display device which implements a single cell gap mode by simultaneously forming a flattening layer in a transmissive portion and an additional voltage adjusting layer in the reflective portion when embossing is formed in the reflective portion. will be.

Recently, researches on flat panel displays have been actively conducted. Among them, liquid crystal displays (LCDs), Feiled Emission Displays (FEDs), electroluminescence devices (ELDs), and plasma display panels (PDPs) have been in the spotlight.

Among the flat panel displays, the liquid crystal display device has a high contrast ratio, is suitable for gray scale display and moving image display, and has low power consumption.

The liquid crystal display may be classified into two types, a transmissive liquid crystal display device using a backlight as a light source and a reflective liquid crystal display device using external natural light without using the backlight as a light source. Although it is possible to realize a bright image, the power consumption is large, and the reflection type liquid crystal display device does not use a backlight, so power consumption is reduced. However, when the external natural light is dark, there is a limitation that it is impossible to use.

Therefore, in electronic devices such as clocks and calculators that require minimal power consumption, reflective liquid crystal display devices are often used, and transmissive liquid crystal display devices are commonly used in notebook computers that require high quality image display.

Recently, researches on semi-transmissive liquid crystal display devices, which have made up for the shortcomings of the reflective liquid crystal display device and the transmissive liquid crystal display device, have been actively conducted. It is possible to use both ways.

That is, when the external natural light is bright enough to enable the display function without using the backlight, the external light incident through the upper substrate is reflected by the reflective electrode to operate as a reflective liquid crystal display device, and when the external light is not bright, the backlight is used. The light of the backlight is incident on the liquid crystal layer through the opening of the reflective electrode to operate as a transmissive liquid crystal display device.

In this case, in order to maximize the efficiency of the reflector and the transmitter, a dual-cell gap scheme has been proposed in which the transmitter cell gap is about twice the reflector cell gap.

Recently, a method of applying a transverse electric field type liquid crystal display device in a transflective mode has been proposed. In this case, the electrode may be configured in a dual-cell gap method to maximize the efficiency of the transflective mode.

Hereinafter, a translucent liquid crystal display device according to the prior art will be described in detail with reference to the accompanying drawings.

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

A semi-transmissive liquid crystal display device in which one pixel area is divided into a reflection part R and a transmission part T, and the liquid crystal is driven by a transverse electric field, includes a thin film transistor array substrate having a plurality of wirings and a thin film transistor; A color filter array substrate facing the thin film transistor array substrate, and a liquid crystal layer encapsulated between the thin film transistor array substrate and the color filter array substrate.

At this time, the liquid crystal layer 531 is composed of a dual-cell gap in which the liquid crystal layer cell gap of the transmission portion T is twice as large as the liquid crystal layer cell gap of the reflection portion R, as shown in FIG. 1.

As described above, in order to form the liquid crystal layer with a dual-cell gap, the reflective electrode 590 is formed to form the organic insulating film 518 only in the reflective portion R and reflects external light on the organic insulating film 518. Equipped. In the transmission part T, only a transmission electrode (not shown) is formed without an organic insulating layer. That is, the liquid crystal cell gap becomes a double step due to the step of the organic insulating film 518 of the reflecting portion R.

In this manner, the cell gap d of the transmission part and the cell gap d / 2 of the reflection part are formed in a ratio of about 2: 1 to match the on / off modes of the reflection part and the transmission part.

Specifically, the light incident to the reflector and the light incident to the transmissive part simultaneously reach the screen surface. Natural light incident to the reflector R from the outside reaches the screen surface by reciprocating the liquid crystal layer 531 from the top. Since the light incident from the backlight to the transmissive part T passes through the transmissive part liquid crystal layer, which is twice the reflector cell gap, and reaches the screen surface, it eventually reaches the screen surface.

On the other hand, the semi-transmissive liquid crystal display device having a double cell gap divided into a reflecting part and a transmitting part has an alignment film (not shown) for arranging molecules of the liquid crystal layer 531 in a predetermined direction on the inner surfaces of the TFT array substrate and the color filter array substrate. C) is further provided, and polarizing films 550 and 551 are further provided on the outer surfaces of the two substrates to adjust the optical axis of the light.

Further, QWP (Quater Wave Plate) films 562 and 563 are further provided between the liquid crystal layer 531 and the polarizing films 550 and 551 to delay the phase difference.

However, when only the QWP film is used, there is a disadvantage in that the reflectance is different for each wavelength, which means that when the colors of R, G, and B are reflected, their reflectances are different from each other, resulting in poor image quality.

In order to prevent this, there is further provided a half wave plate (HWP) film (561,564) between the polarizing film (550,551) and the QWP film (562,563) to have the effect of disposing a wideband QWP, thereby uniformizing the entire visible light wavelength Let it show one reflectance. As described above, in the case of the transflective liquid crystal display device, a polarizing film, a compensation film (QWP, HWP), a liquid crystal layer, a compensation film (HWP, QWP), it is generally composed of a laminated structure of the polarizing film.

However, the transflective liquid crystal display device according to the prior art as described above has the following problems.

That is, when the reflector cell gap is d / 2, the reflector R has a phase delay effect of 2 × d / 2 × Δn because external light reciprocates through the liquid crystal layer. Therefore, in order to optimize the light efficiency of the reflector, cell gap tuning should be performed at an optimum value near the transmittance cell gap, but it is not easy to accurately design the reflector cell gap to 1/2 of the transmittance cell gap.

When the cell gap of the reflector is not exactly matched, a difference in the form of the T-V curve (Transmittance-Voltage Curve) of the reflector and the transmitter occurs, and the brightness of the white display of the reflector is reduced.

In addition, when the difference between the reflecting portion and the transmitting portion is large, the alignment of the liquid crystal becomes incomplete in the step boundary, and thus there is a problem that the image quality deteriorates.

Accordingly, the present invention has been made to solve the above problems, and when the embossing is formed in the reflector, the planarization layer is formed at the same time and the voltage control layer is added to the reflector to form a single cell gap mode (single cell-gap mode). The purpose of the present invention is to provide a semi-transmissive liquid crystal display device and a method of manufacturing the same to solve the design and process difficulties for implementing the dual cell gap and to improve characteristics related to image quality such as contrast ratio (CR). have.

The semi-transmissive liquid crystal display device of the present invention for achieving the above object is a gate wiring and data wiring defining a pixel region consisting of a reflecting portion and a transmissive portion vertically intersecting on the first substrate, and the gate wiring and data wiring of the A thin film transistor formed at an intersection point, a protective film formed on the entire surface including the thin film transistor, a first transmission electrode formed at a transmission portion of the pixel region, a reflection electrode formed at a reflection portion of the pixel region, and the pixel And a liquid crystal layer having a single cell gap between the voltage regulating layer formed on the reflecting portion of the region and opposingly bonded to the first substrate and having a second cell therebetween.

In addition, a method of manufacturing a transflective liquid crystal display device for achieving another object of the present invention defines a pixel area divided into a reflecting part and a transmitting part by vertically forming a gate line and a data line on a first substrate, Forming a thin film transistor at an intersection point, forming a protective film on the entire surface including the thin film transistor, forming a first transmissive electrode on a predetermined portion including a transmissive part on the protective film, Forming a reflective electrode on the first transmission electrode, and bonding a second substrate to face the first substrate, and forming a liquid crystal layer having a single cell gap therebetween.

In this case, the liquid crystal is further provided with a second transmission electrode which is insulated from the first transmission electrode and the reflection electrode by an interlayer insulating film, and includes a plurality of slits to form a transverse electric field between the first transmission electrode and the reflection electrode. The liquid crystal layer is driven by driving a layer or further including a common electrode on an inner surface of the second substrate.

As described above, the transflective liquid crystal display device according to the present invention is characterized in that the liquid crystal cell gap of the reflecting portion R and the liquid crystal cell gap of the transmissive portion T are realized as a single cell gap, and thus the phase delay of the reflecting portion and the transmitting portion is implemented. In order to make the same, a voltage regulating layer is additionally provided to the reflector.

In the case where the uneven pattern is formed in the reflective part R, a flattening layer having the same level as that of the uneven pattern is formed in the transmissive part T to make the level of the transmissive part and the reflective part uniform.

In this way, by configuring the transflective liquid crystal display element in the single cell gap mode, the contrast ratio decrease due to the difference in the TV curve shape between the reflecting portion and the transmitting portion due to the dual cell gap is improved, and the step boundary portion due to the step between the reflecting portion and the transmitting portion is improved. Can improve image quality nonuniformity.

A transflective liquid crystal display device and a method of manufacturing the same according to the present invention having the above characteristics will be described in detail with reference to the accompanying drawings.

The following description mainly relates to a thin film transistor substrate.

First embodiment

FIG. 2 is a pixel plan view of a transflective liquid crystal display device according to a first exemplary embodiment of the present invention, FIG. 3 is a cross-sectional view taken along line II ′ of FIG. 2, and FIGS. 4A to 4F are first views of the present invention. The process cross section of the transflective liquid crystal display element by an Example.

As shown in FIGS. 2 and 3, the transflective liquid crystal display device according to the first embodiment of the present invention comprises a first transmissive electrode through which the Vcom voltage flows and a second transmissive electrode through which the pixel voltage flows over the reflective electrode. The transverse electric field is formed between the slits of the second transmission electrode, and the liquid crystal cell gap of the reflection part R and the liquid crystal cell gap of the transmission part T are implemented as a single cell gap. An additional adjustment layer 116 is provided. When the uneven pattern 160 is formed in the reflective part R, the planarization layer 161 having the same level as that of the uneven pattern is formed in the transmissive part T. At this time, the concave-convex pattern (not shown) may be formed in the same manner as the reflecting portion without forming the planarization layer in the transmissive portion.

Here, the TFT array substrate 111 includes a gate wiring 112 and a data wiring 115 that vertically intersect to define a unit pixel region, a thin film transistor TFT formed at an intersection point of the gate wiring and the data wiring; A first transmission electrode 150 formed in the transmission part T of the unit pixel region, a reflection electrode 124 and a voltage regulating layer 116 sequentially formed in the reflection part R of the unit pixel region, An interlayer insulating layer 118 formed on the entire surface including the voltage regulating layer 116 and a second transmission electrode 117 formed on the interlayer insulating layer 118 and including a plurality of slits are formed.

At this time, the first transverse electric field formed between the first transmission electrode 150 and the second transmissive electrode 117 and the second transverse electric field formed between the reflective electrode 124 and the second transmissive electrode 117. The first transmission electrode 150 is integrally connected to the first transmission electrode of an adjacent unit pixel region to receive the Vcom voltage from the outside of the active region, and the reflection electrode 124 is the first transmission electrode 150. It is formed on the first transmission electrode and directly receives the Vcom voltage, and the second transmission electrode 117 is connected to the drain electrode 115b of the thin film transistor to receive the pixel voltage.

That is, the transflective liquid crystal display device according to the first embodiment of the present invention is driven by a transverse electric field. When there is no external light source, the first transmission electrode 150 and the second transmission electrode ( It is driven in the transmissive mode by the first transverse electric field between the 117, and when there is an external light source, by the second transverse electric field between the reflecting electrode 124 and the second transmissive electrode 117 of the reflector R. It is driven in reflection mode.

In this case, the transverse electric field may be formed by applying the pixel voltage by contacting the first transmission electrode and the reflection electrode to the drain electrode and applying the Vcom voltage to the second transmission electrode having a plurality of slits.

A gate insulating film (not shown) is formed between the gate wiring and the data wiring to insulate the two layers, and a protective film (not shown) is formed on the entire surface including the thin film transistor, and the thin film transistor is formed on the gate wiring. A gate electrode 112a formed simultaneously with the gate electrode, a gate insulating film formed on the gate electrode, a semiconductor layer (not shown) formed on the gate insulating film over the gate electrode, and a source / drain electrode 115a formed simultaneously with the data line. It consists of a laminated film of 115b).

On the other hand, the concave-convex pattern 160 may be further formed only in the reflecting portion, and convex-concave occurs in the reflective electrode 124 along the curved surface of the concave-convex pattern. The reflective unevenness of the reflective electrode serves to widen the viewing angle by locally changing the reflection angle of the external natural light when the external natural light is used as the light source. In this case, the reflective electrode 124 may be formed to be limited to only the reflective region of the unit pixel region, and may be formed to overlap the gate wiring, the data wiring, and the thin film transistor to prevent light leakage.

As described above, when the uneven pattern is formed in the reflective part R, the flattening layer 161 is further provided in the transmissive part to eliminate the step difference between the transmissive part and the reflective part. The concave-convex pattern may be formed in the transmissive portion similarly to the concave-convex pattern of the reflecting portion without forming the planarization layer.

The semi-transmissive liquid crystal display device has a single cell gap mode by forming a flattening layer in the transmissive part to make the level difference of the transmissive part of the reflecting part the same when the uneven pattern is formed in the reflecting part. Therefore, the difference in the shape of the T-V curve due to the step difference between the reflecting unit and the transmitting unit may be minimized, thereby preventing the brightness of the white display of the reflecting unit from decreasing, thereby improving the contrast ratio. The deterioration of image quality at the step boundary is also improved by eliminating the step between the reflecting part and the transmitting part.

In this case, the voltage adjusting layer 116 is further provided in the reflecting unit so that the phase difference between the image reaching the screen surface in the reflecting unit and the transmitting unit is the same. By inserting the voltage adjusting layer, the reflector driving voltage is reduced. That is, the voltage adjusting layer makes the phase difference d2 × Δn of the reflecting part equal to 1/2 of the phase difference d1 × Δn of the transmitting part, and the effective thickness T _{eff of the} voltage adjusting layer or the dielectric constant of the voltage adjusting layer. Adjust the reflector driving voltage accordingly. The voltage regulating layer may be formed using a photoresist or photoacryl, and the like, and a voltage regulating layer having a dielectric constant in the range of 3 to 7 may be used.

The TFT array substrate 111 is opposed to the color filter array substrate 121 on which the color filter layer (not shown) is formed, and the liquid crystal layer 131 is provided therebetween, and the pattern of the TFT array substrate is a reflector. The liquid crystal layer 131 also has a single cell gap because of a uniform step in the transmissive part.

Hereinafter, a manufacturing method of the TFT array substrate will be described.

First, as shown in FIG. 4A, a protective film (not shown) is formed on a TFT array substrate 111 on which gate wirings, data wirings, and thin film transistors are already formed, and BCB (Benzocyclobutene) and acrylic resin ( Organic insulation such as acryl resin) is applied or silicon nitride (SiNx) or silicon oxide (SiOx) is deposited and patterned by a photolithography process to form irregularities pattern 160 having a predetermined interval on the reflecting portion R, and a transmissive portion ( The planarization layer 161 is formed in T). The flattening layer is for uniformizing the step between the reflecting portion and the transmissive portion, and the uneven pattern may be formed in the same manner as the reflecting portion without forming the flattening layer on the transmissive portion.

Next, a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO) is deposited on the entire surface including the uneven pattern 160 and the planarization layer 161 to form the first transmission electrode material layer 150a. Form.

Subsequently, a reflective electrode metal layer 124a having excellent reflectance characteristics, such as aluminum (Al), copper (Cu), and chromium (Cr), is deposited on the entire surface including the first transmission electrode material layer 150a, and FIG. 4B. As shown in Fig. 3, photoresist 116 is applied thereon. In this case, in addition to the photoresist, photoacryl may be used, and the photoresist remaining in the reflecting unit in a later process becomes a voltage regulating layer.

Subsequently, the photoresist is diffracted and developed using a diffraction exposure mask 190 to form a double-stage photoresist 116, as shown in FIG. 4C. At this time, a low stepped photoresist is formed in the transmissive portion of the pixel region, a high stepped photoresist is formed in the reflective portion of the pixel region, and the photoresist is removed in a region other than the pixel region. The step of the transmissive portion and the reflecting portion is the thickness of the voltage adjusting layer.

Specifically, the photoresist 116 is coated on a substrate with a uniform thickness, and the photoresist is patterned to have a double step after diffraction exposure by applying a diffraction exposure mask thereon.

The diffraction exposure mask is divided into three regions: a transparent region, a translucent region, and a light shielding region. In the transparent region, the light transmittance is 100%, and the light blocking region has a light blocking layer 190a, so the light transmittance is 0%. In the translucent region, the translucent layer 190b is formed so that the light transmittance is 0% or more and 100% or less.

Therefore, the remaining thickness of the diffracted exposure and developed photoresist is also divided into three regions: a full exposure portion corresponding to the transparent region of the diffraction exposure mask, a full non-exposure portion corresponding to the light shielding region, and a diffraction exposure portion corresponding to the translucent region. . As such, the diffractive photoresist is completely removed only in the fully exposed portion, formed thinner than other portions in the diffractive exposure portion, and remains intact only in the completely non-exposed portion.

In this case, the diffractive exposure portion corresponds to the transmission portion of the pixel region, the completely non-exposure portion corresponds to the reflection portion of the pixel region, and the complete exposure portion corresponds to the region other than the transmission portion and the reflection portion.

As described above, after the photoresist is formed in a double step, as shown in FIG. 4D, the first transparent electrode material layer 150a and the reflective electrode metal layer 124a of the fully exposed portion are formed using the photoresist as a mask. ) To form a first transmissive electrode 150, and then ash the photoresist until the reflective electrode metal layer 124a of the transmissive portion T is exposed to the outside. The metal layer for the reflective electrode of the transmission part is wet etched using HF (Hydrofluoric Acid), BOE (Buffered Oxide Etchant), NH ₄ F or a mixture thereof. As a result, the voltage adjusting layer 116 and the reflecting electrode 124 are completed in the reflecting portion, and the reflecting electrode has a rough surface due to the uneven pattern, thereby preventing mirror reflection of external light and securing a viewing angle.

As such, since the voltage regulation layer formation and the reflective electrode patterning process may be performed by one photo etching process, a separate photo etching process may not be added. Further, by using the diffraction exposure mask, the patterning process of the transmission electrode can also be performed at the same time as the voltage regulation layer forming process and the reflecting electrode patterning process. Of course, the transmission electrode patterning process may be performed by a separate photo etching process without using a diffraction exposure mask.

In this case, the first transmission electrode may be limited to the transmission part or may be formed on the entire pixel region including the transmission part. The driving voltage of the voltage adjusting layer is adjusted according to its effective thickness or dielectric constant. In addition, since the reflective electrode that transmits the Vcom signal is formed in the area of half of the pixel area, the resistance can be lowered to solve the problem of poor image quality such as horizontal crosstalk or greenish due to Vcom signal distortion. have.

Thereafter, as shown in FIG. 4E, organic insulation such as BCB (Benzocyclobutene), acrylic resin (acryl resin), or the like is applied to the entire surface including the voltage regulating layer 116 or silicon nitride (SiNx) or silicon oxide (SiOx). Is deposited to form an interlayer insulating film 118. In this case, the interlayer insulating film of the reflector R may be removed to minimize the decrease of the reflector driving voltage.

Finally, as illustrated in FIG. 4F, a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO) is deposited and patterned on the entire surface including the interlayer insulating layer 118 to include a plurality of slits. The second transmission electrode 124 is formed.

In this case, the second transmission electrode 124 is formed to be parallel to the first transmission electrode 117 in the transmission part T to form a horizontal first horizontal electric field driving the transmission mode, and the reflection part R At the reflective electrode 120 to form a second horizontal electric field in a horizontal direction to drive the reflection mode.

Meanwhile, the first transmission electrode 150 or the reflection electrode 124 is integrally formed with the first transmission electrode or the reflection electrode of the adjacent pixel region so that a common voltage is applied from the outside of the active region, and the second transmission electrode Reference numeral 117 contacts the drain electrode through the contact hole from which the passivation layer and the interlayer insulating layer on the drain electrode of the thin film transistor are removed so that the pixel voltage is applied. However, the pixel electrode may be applied by contacting the first transmission electrode and the reflection electrode to the drain electrode, and the second transmission electrode may be integrally formed with the second transmission electrode of the adjacent pixel region to apply the Vcom voltage. .

Subsequently, although not shown, the color filter array substrate on which the color filter layer is formed is bonded to face the TFT array substrate, and a liquid crystal layer is formed between the two substrates to complete a transverse electric field type liquid crystal display device having a single cell gap.

Second embodiment

FIG. 5 is a pixel plan view of a transflective liquid crystal display device according to a second exemplary embodiment of the present invention, FIG. 6 is a cross-sectional view taken along line II-II 'of FIG. 5, and FIGS. 7A to 7E are second views of the present invention. The process cross section of the transflective liquid crystal display element by an Example.

In the transflective liquid crystal display device according to the second embodiment of the present invention, as shown in FIGS. 5 and 6, the reflective electrode and the transmissive electrode of the TFT array substrate and the color filter array substrate facing the TFT array substrate are common. A vertical electric field is formed between the electrodes to control the alignment of the liquid crystal layer. The liquid crystal cell gap of the reflector R and the liquid crystal cell gap of the transmissive part T are implemented as a single cell gap. An additional voltage adjusting layer 16 is provided. When the uneven pattern 60 is formed in the reflecting portion R, the planarization layer 61 having the same level as that of the uneven pattern is formed in the transmissive portion T. At this time, the concave-convex pattern (not shown) may be formed in the same manner as the reflecting portion without forming the planarization layer in the transmissive portion.

Here, as shown in Figs. 5 and 6, the TFT array substrate 11 includes a gate wiring 12 and a data wiring 15 defining a unit pixel region by vertical crossing, and the gate wiring and data wiring. The thin film transistor TFT formed at the intersection point, the transmissive electrode 50 formed in the transmissive portion T of the unit pixel region, and the reflective electrode 24 formed sequentially in the reflecting portion R of the unit pixel region. ) And the voltage regulation layer 16 is formed.

In this case, the transmission electrode 50 and the reflection electrode 24 are directly and indirectly contacted with the drain electrode 15b of the thin film transistor to receive the pixel voltage at the same time. In the drawing, a pixel voltage is simultaneously applied by forming a transmissive electrode in all regions of the transmissive part and the reflecting part, and defining the reflecting electrode on the transmissive electrode.

A gate insulating film (not shown) is formed between the gate wiring and the data wiring to insulate the two layers, and a protective film (not shown) is formed on the entire surface including the thin film transistor, and the thin film transistor is a gate electrode 12a. ), A gate insulating film, a semiconductor layer (not shown), and a stacked film of source / drain electrodes 15a and 115b.

Meanwhile, the uneven pattern 60 may be further formed only in the reflecting portion. The uneven pattern 60 may be formed along the curved surface of the uneven pattern to cause unevenness of the reflecting electrode, and the reflecting electrode 24 may be formed in the reflecting region of the unit pixel region. In addition to forming only limited, it may be formed so as to overlap with the gate wiring, data wiring and the thin film transistor to prevent light leakage.

As described above, when the uneven pattern is formed in the reflecting portion R, the flattening layer 61 is further provided in the transmitting portion in order to eliminate the step difference between the transmitting portion and the reflecting portion. The concave-convex pattern may be formed in the transmissive portion similarly to the concave-convex pattern of the reflecting portion without forming the planarization layer.

When the semi-transmissive liquid crystal display device forms a concave-convex pattern on the reflecting portion, a flattening layer is formed on the transmissive portion to realize the single cell gap mode by making the level difference of the transmissive portion of the reflecting portion the same. Therefore, the difference in the shape of the T-V curve due to the step difference between the reflecting unit and the transmitting unit is minimized, thereby preventing the brightness of the white display of the reflecting unit from being reduced, thereby improving the contrast ratio. The deterioration of image quality at the step boundary is improved by eliminating the step between the reflecting part and the transmitting part.

At this time, the voltage adjusting layer 16 is further provided in the reflecting unit so that the phase difference of the image reaching the surface of the screen from the reflecting unit and the transmitting unit is the same. By inserting the voltage adjusting layer, the reflector driving voltage is reduced. That is, the phase difference d2 × Δn of the reflector is equal to 1/2 the phase difference d1 × Δn of the transmissive part, which is dependent on the effective thickness Teff of the voltage adjusting layer or the dielectric constant of the voltage adjusting layer. Use the adjustable one to select the voltage control layer. The voltage regulating layer may be formed using a photoresist or photoacryl.

The TFT array substrate 11 is bonded to the color filter array substrate 21 having the common electrode 24 and the color filter layer (not shown) formed on the front surface thereof, and the liquid crystal layer 31 is provided therebetween. Since the pattern of the TFT array substrate has uniform steps in the reflecting portion and the transmitting portion, the liquid crystal layer also becomes a single cell gap.

Hereinafter, a manufacturing method of the TFT array substrate will be described.

First, as shown in FIG. 7A, a protective film (not shown) is formed on a TFT array substrate 11 on which gate wirings, data wirings, and thin film transistors are already formed, and BCB (Benzocyclobutene) and acrylic resin ( Applying organic insulation such as acryl resin, or depositing silicon nitride (SiNx), silicon oxide (SiOx) and patterning by photolithography process to form irregularities at regular intervals in the reflecting portion (R), and to the transmissive portion (T) The planarization layer 61 is formed. The flattening layer is for uniformizing the step between the reflecting portion and the transmissive portion, and the uneven pattern may be formed in the same manner as the reflecting portion without forming the flattening layer on the transmissive portion.

Next, after forming the contact hole by removing the protective layer on the drain electrode, a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO) on the entire surface including the uneven pattern 60 and the planarization layer 61. The material is deposited to form a material layer 50a for the transmissive electrode.

Subsequently, a reflective electrode metal layer 24a having excellent reflectance characteristics, such as aluminum (Al), copper (Cu), and chromium (Cr), is deposited on the entire surface including the transmissive electrode material layer 50a, as shown in FIG. 4B. As described above, the photoresist 16 is applied thereon at a constant thickness. At this time, photoacryl can be used other than a photoresist.

Subsequently, by diffraction exposure and development of the photoresist using a diffraction exposure mask 90, as shown in Fig. 7C, a double-stage photoresist 16 is formed. At this time, the photoresist of the transmissive part has a low step, the photoresist of the reflective part has a high step, and the photoresist at the edge of the pixel region other than the transmissive part and the reflecting part is completely removed. It becomes the thickness of a control layer.

Subsequently, the transmissive electrode material layer and the reflective electrode metal layer are etched using the photoresist as a mask to form a transmissive electrode, and as shown in FIG. 7D, until the reflective electrode metal layer is exposed to the outside. The photoresist is ashed, and the metal layer for the reflective electrode is wet-etched using the ashed photoresist as a mask. As a result, the voltage adjusting layer 16 and the reflecting electrode 24 are completed in the reflecting portion, and the reflecting electrode has a rough surface due to the uneven pattern, thereby preventing mirror reflection of external light and securing a viewing angle.

As such, since the voltage regulation layer formation and the reflective electrode patterning process may be performed by one photo etching process, a separate photo etching process may not be added. At this time, the driving voltage of the reflector is adjusted according to the effective thickness or dielectric constant of the voltage adjusting layer.

Subsequently, as shown in FIG. 7E, an organic insulation such as BCB (Benzocyclobutene), an acrylic resin (acryl resin), or the like is applied to the entire surface including the voltage regulating layer 16 or silicon nitride (SiNx) or silicon oxide (SiOx). May be deposited to form an interlayer insulating film 18. In this case, the interlayer insulating film of the reflector R may be removed to minimize the decrease of the reflector driving voltage.

Subsequently, although not shown, a color filter array substrate having a common electrode and a color filter layer formed thereon is bonded to face the TFT array substrate, and a liquid crystal layer is formed between the two substrates to complete a transverse electric field type liquid crystal display device having a single cell gap. do.

On the other hand, the present invention described above is not limited to the above-described embodiment and the accompanying drawings, it is possible that various substitutions, modifications and changes within the scope without departing from the technical spirit of the present invention. It will be apparent to those of ordinary skill in Esau.

The transflective liquid crystal display device and the method of manufacturing the same according to the present invention as described above have the following effects.

First, when embossing the reflective part, the planarization layer is formed simultaneously in the transmissive part, and the voltage control layer is added to the reflective part to realize the single cell gap mode, thereby implementing a dual cell gap. Can be solved. In addition, it is possible to prevent rubbing defects from occurring due to the difference between the reflecting portion and the transmitting portion, thereby improving image quality unevenness in the step boundary portion.

Second, by configuring the transflective liquid crystal display device in the single cell gap mode, it is possible to reduce the contrast ratio due to the difference in the T-V curve shape between the reflecting part and the transmitting part due to the dual cell gap.

Third, since the reflective electrode that transmits the Vcom signal is formed in half the area of the pixel area, the resistance can be lowered to solve the problem of poor image quality such as horizontal crosstalk and greenish due to Vcom signal distortion. have.

Claims (25)

A gate wiring and a data wiring defining a pixel region composed of a reflecting portion and a transmitting portion vertically intersecting on the first substrate; A thin film transistor formed at an intersection point of the gate line and the data line; A protective film formed on the entire surface including the thin film transistor, A first transmission electrode formed in the transmission portion of the pixel region; A reflective electrode formed on the reflective portion of the pixel region; A voltage regulating layer formed on the reflecting portion of the pixel region; A second transmission electrode insulated from the first transmission electrode and the reflection electrode by an interlayer insulating film, the second transmission electrode including a plurality of slits to form a transverse electric field between the first transmission electrode and the reflection electrode; And a liquid crystal layer bonded to the first substrate and having a single cell gap between the first substrate and the second substrate. The method of claim 1, A semi-transmissive liquid crystal display device, characterized in that the uneven pattern is further provided in the reflecting portion of the pixel region. The method of claim 2, The transflective liquid crystal display device further comprising a flattening layer or an uneven pattern having the same level as that of the uneven pattern of the reflecting portion in the transmissive portion of the pixel region. The method of claim 1, The voltage regulating layer is a transflective liquid crystal display device, characterized in that formed using a photoacrylic resin, photoresist. The method of claim 1, The liquid crystal layer phase retardation of the reflective part and the transmissive part is controlled by the thickness and the dielectric constant of the voltage adjusting layer. The method of claim 1, And a pixel voltage is applied to the reflective electrode and the first transmission electrode and a Vcom voltage is applied to the second transmission electrode. The method of claim 1, A transflective liquid crystal display device, wherein a Vcom signal is applied to the reflective electrode and the first transmission electrode and a pixel voltage is applied to the second transmission electrode. The method of claim 1, And the interlayer insulating film is provided over the entire surface of the substrate or limited to the transmissive portion of the pixel region. A gate wiring and a data wiring defining a pixel region composed of a reflecting portion and a transmitting portion vertically intersecting on the first substrate; A thin film transistor formed at an intersection point of the gate line and the data line; A protective film formed on the entire surface including the thin film transistor, A transmissive electrode formed in the transmissive part of the pixel region and contacting the drain electrode of the thin film transistor; A reflection electrode formed in the reflection portion of the pixel region and contacting the drain electrode or the transmission electrode of the thin film transistor; A voltage regulating layer formed on the reflecting portion of the pixel region; A second substrate opposed to the first substrate and provided with a common electrode on an inner surface thereof; A semi-transmissive liquid crystal display device comprising a liquid crystal layer having a single cell gap formed between the first substrate and the second substrate. The method of claim 9, A semi-transmissive liquid crystal display device, characterized in that the uneven pattern is further provided in the reflecting portion of the pixel region. The method of claim 10, The transflective liquid crystal display device further comprising a flattening layer or an uneven pattern having the same level as that of the uneven pattern of the reflecting portion in the transmissive portion of the pixel region. The method of claim 9, The voltage regulating layer is a transflective liquid crystal display device, characterized in that formed using a photoacrylic resin, photoresist. The method of claim 9, The liquid crystal layer phase retardation of the reflective part and the transmissive part is controlled by the thickness and the dielectric constant of the voltage adjusting layer. The method of claim 9, A transflective liquid crystal display device further comprising an interlayer insulating film on the entire surface of the substrate including the reflective electrode or an interlayer insulating film in addition to the transmissive portion of the pixel region. Forming a pixel region divided into a reflection part and a transmission part by vertically forming a gate line and a data line on the first substrate, and forming a thin film transistor at an intersection point of the two lines; Forming a protective film on the entire surface including the thin film transistor; Forming a first transmission electrode on a predetermined portion including the transmission part on the passivation layer; Forming a reflective electrode on the first transmissive electrode only in the reflective part; A method of manufacturing a transflective liquid crystal display device, comprising bonding a second substrate to face the first substrate and forming a liquid crystal layer with a single cell gap therebetween. The method of claim 15, After forming the reflective electrode, Forming an interlayer insulating film on the reflective electrode; And forming a second transmission electrode on the interlayer insulating layer to form a transverse electric field together with the first transmission electrode and the reflection electrode. The method of claim 16, The first transmissive electrode is contacted with the drain electrode of the thin film transistor through the passivation layer, and the second transmissive electrode is integrally formed with the second transmissive electrode of the adjacent pixel region. Manufacturing method. The method of claim 16, The method of manufacturing a transflective liquid crystal display device, wherein the second transmission electrode is contacted with a drain electrode of the thin film transistor, and the first transmission electrode is integrally formed with a first transmission electrode of an adjacent pixel region. The method of claim 16, The method of manufacturing a transflective liquid crystal display device, characterized in that the interlayer insulating film on the voltage control layer is removed or not removed. The method of claim 15, And forming a common electrode on the inner surface of the second substrate together with the first transmission electrode and the reflection electrode to form an electric field. The method of claim 20, And the first transmission electrode contacts the drain electrode of the thin film transistor through a contact hole formed by removing the passivation layer. The method of claim 15, Forming a voltage adjusting layer on the reflective electrode; Forming the reflective electrode is a method of manufacturing a transflective liquid crystal display device, characterized in that at the same time in the same mask process. The method of claim 22, A method of manufacturing a transflective liquid crystal display device, characterized in that a diffraction exposure mask is used in the mask process. The method of claim 15, A method of manufacturing a transflective liquid crystal display device further comprising the step of forming an uneven pattern on the reflecting portion before forming the passivation layer. The method of claim 24, A method of manufacturing a transflective liquid crystal display device, wherein at the time of forming the uneven pattern, the planarization layer or the uneven pattern is formed simultaneously in the transmission portion.

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