KR101343492B1 - Transflective liquid crystal display device and fabricating thereof - Google Patents

Abstract

Semi-transmissive liquid crystal display device and a method of manufacturing the same to form a light blocking metal in the step region during the array substrate manufacturing process in order to prevent light leakage caused by the step between the transmissive portion and the reflecting portion in the semi-permeable dual gap structure A method comprising: providing a first substrate on which a pixel region is defined; Forming a gate wiring on the first substrate and forming a light blocking metal on the same layer as the gate wiring by using the same material as the gate wiring; Forming a gate insulating film on the first substrate on which the gate wiring and the light blocking metal are formed; Forming an active layer and a data line on the first substrate on which the gate insulating film is formed; Forming a first passivation layer on the first substrate on which the active layer and the data pattern are formed; Forming and patterning an inorganic or organic insulating material on the first protective film, and depositing and patterning an opaque conductive material thereon to form a laminated structure of a lower layer of the insulating material and an upper layer of the opaque conductive material, Forming a reflecting plate whose upper layer surface has an uneven shape; Forming a second passivation layer on the first substrate on which the reflective plate is formed; Forming a pixel electrode on the second passivation layer corresponding to the pixel region with a transparent conductive material; Bonding the second substrate to the first substrate at a predetermined interval from the first substrate; And injecting a liquid crystal between the first substrate and the second substrate, wherein the reflective plate is positioned to correspond to the pixel area on the second passivation layer, and the rectangular area is removed to transmit light. It has a shape, the light blocking metal is positioned corresponding to the inner edge of the rectangular rim reflector is characterized in that to block the transmission of light.

Transflective, light blocking metal

Description

Transflective liquid crystal display device and its manufacturing method {TRANSFLECTIVE LIQUID CRYSTAL DISPLAY DEVICE AND FABRICATING THEREOF}

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

2 is a perspective view of first and second substrates of a transflective liquid crystal display according to the present invention;

3 is a cross-sectional view of the transflective liquid crystal display shown in FIG.

4 is a plan view of a unit pixel of the transflective liquid crystal display according to the present invention.

5A to 5E are views showing the manufacturing process along the cut plane III-III 'of the unit pixel shown in FIG.

Explanation of symbols on the main parts of the drawings

110: first substrate 111: light blocking metal

112a: gate electrode 114: gate insulating film

116: active layer 118a, 118b: ohmic contact layer

120a, 120b: source / drain electrodes

The present invention relates to a transflective liquid crystal display device and a method for manufacturing the same, and more particularly, to prevent light leakage caused by a step between a transmissive part and a reflective part in a transflective dual gap structure. It is concerned with further forming a gate metal in the stepped region.

In general, a liquid crystal display device bonds two substrates on which electric field generating electrodes are formed to face each other, injects a liquid crystal material between the two substrates, and then applies liquid crystals to the liquid crystal molecules by applying a voltage to the two electrodes. By moving, it is a device for expressing the image by adjusting the transmittance of light that varies accordingly. However, as mentioned above, the liquid crystal display device requires a separate light source because it is a light receiving device that cannot emit light by itself. Therefore, a backlight device is provided on the rear surface of the liquid crystal panel and the light emitted from the backlight is incident on the liquid crystal panel to adjust the amount of light according to the arrangement of the liquid crystals to display an image. In this case, the field generating electrode of the liquid crystal display device is formed of a transparent conductive material, the two substrates should also be made of a transparent substrate.

Such a liquid crystal display device corresponds to a transmission type liquid crystal display device. Since an artificial back light source such as a backlight is used, a bright image may be realized even in a dark external environment, but power consumption due to the backlight is increased.

It is nonetheless a reflection type liquid crystal display device designed to compensate for this disadvantage. This is a form in which light transmittance is adjusted according to the arrangement of liquid crystals by reflecting external natural or artificial light, which consumes less power than a transmissive liquid crystal display. However, since the reflective liquid crystal display device has a structure in which most of the light is dependent on external natural light or artificial light sources, the reflective liquid crystal display device consumes less power than the transmissive liquid crystal display device but cannot be used in a dark place.

Accordingly, a liquid crystal display device having both a reflection and a transmission has been proposed as a device capable of appropriately selecting and using two modes of reflection and transmission.

Next, a general transflective liquid crystal display device will be described in detail with reference to the accompanying drawings. 1 is a partial cross-sectional view of a general transflective liquid crystal display device. As shown in the figure, the first substrate 10 and the second substrate 30 are arranged at a predetermined interval. First, a gate electrode 12 is formed on the first substrate 10 below the gate. The insulating film 13 is formed. Of course, before the gate insulating layer 13 is formed, a gate wiring connected to the gate electrode 12 is further formed below.

Next, the active layer 14 and the ohmic contact layers 15a and 15b are sequentially formed on the gate insulating layer 13, and the source and drain electrodes 16a and 16b are formed again on the ohmic contact layers 15a and 15b. The source and drain electrodes 16a and 16b are formed together with the gate electrode 12 to form a thin film transistor. Of course, here as before, a data line (not shown) of a material such as the source and drain electrodes 16a and 16b is additionally formed on the gate insulating layer 13, and the data line is connected to the source electrode 16a and the gate The pixel area is defined by crossing the wiring.

Subsequently, a first passivation layer 17 made of an organic material is formed on the source and drain electrodes 16a and 16b to cover the thin film transistor. In addition, a reflective plate 18 made of an opaque conductive material is formed in the pixel area on the first passivation layer 17, and a second passivation layer 19 is formed thereon. Here, the second protective layer 19 has a contact hole 19a exposing the drain electrode 16b together with the first protective layer 17.

A pixel electrode 20 made of a transparent conductive material is formed in the pixel area on the second protective layer 19, and the pixel electrode 20 is connected to the drain electrode 16b through the contact hole 19a. . The pixel electrode 20 here serves as a transmission electrode, of course. When the above process is completed, the first alignment layer 21 is subsequently formed.

On the other hand, a black matrix 32 is first formed on the second substrate 30, and then red (R), green (G), and blue (B) color filters 33a and 33b are formed between the black matrices. ) Will be formed sequentially and repeatedly. Here, one color as well as color filters 33a and 33b correspond to one pixel electrode 20, and the black matrix 32 covers edges of the thin film transistor and the pixel electrode 20.

An overcoat layer 34 is formed on the color filters 33a and 33b to protect and planarize the color filters 33a and 33b, and acrylic and polyimide resins are usually used.

Next, a common electrode 35 made of a transparent conductive material is formed on the overcoat layer 34, and a second alignment layer 36 is formed on the common electrode 35.

The liquid crystal layer 40 is positioned between the first and second alignment layers 21 and 36. The liquid crystal used here is usually a twisted nematic liquid crystal, and the liquid crystal molecules of the liquid crystal layer 40 41 is arranged uniformly with a pretilt angle with respect to the substrate.

However, in such a conventional configuration, when the transflective liquid crystal display is driven in the transmissive mode, there is a problem that light leakage occurs at a portion corresponding to the boundary between the transmissive portion T and the reflective portion F. FIG. More precisely, when the alignment layer 36 is formed on the substrate 10 and the rubbing process is performed, light leakage occurs in the boundary region between the reflecting plate 18 and the transmission part T in the direction in which the rubbing process starts. do.

Accordingly, the present invention is to simultaneously pattern the gate metal on the portion corresponding to the boundary region of the reflecting plate 18 and the transmissive portion T when forming the gate electrode of the lower substrate in order to prevent light leakage in the boundary region as described above. have.

And achieving such an object can be further embodied by the present invention. That is, the transflective liquid crystal display according to the present invention comprises: a first substrate; A gate line and a data line formed on the first substrate and defining a pixel area perpendicular to each other; A thin film transistor connected to the gate line and the data line; A rectangular frame shaped reflector positioned to correspond to the pixel region, the center region of which is removed to transmit light; A pixel electrode on the reflective plate corresponding to the pixel area and made of a transparent conductive material; A light blocking metal positioned to correspond to an inner edge of the quadrangular reflector, and formed of the same material as the gate wiring on the same layer as the gate wiring to block light transmission; And a second substrate bonded to the first substrate by being spaced apart from each other by a predetermined distance, wherein the reflecting plate has a laminated structure of a lower layer of an insulating material and an upper layer of an opaque conductive material, while the upper layer has a concave-convex shape. It is done.

In addition, a method of manufacturing a transflective liquid crystal display device may include providing a first substrate on which a pixel region is defined; Forming a gate wiring on the first substrate and forming a light blocking metal on the same layer as the gate wiring by using the same material as the gate wiring; Forming a gate insulating film on the first substrate on which the gate wiring and the light blocking metal are formed; Forming an active layer and a data line on the first substrate on which the gate insulating film is formed; Forming a first passivation layer on the first substrate on which the active layer and the data pattern are formed; Forming and patterning an inorganic or organic insulating material on the first protective film, and depositing and patterning an opaque conductive material thereon to form a laminated structure of a lower layer of the insulating material and an upper layer of the opaque conductive material, Forming a reflecting plate whose upper layer surface has an uneven shape; Forming a second passivation layer on the first substrate on which the reflective plate is formed; Forming a pixel electrode on the second passivation layer corresponding to the pixel region with a transparent conductive material; Bonding the second substrate to the first substrate at a predetermined interval from the first substrate; And injecting a liquid crystal between the first substrate and the second substrate, wherein the reflective plate is positioned to correspond to the pixel area on the second passivation layer, and the rectangular area is removed to transmit light. It has a shape, the light blocking metal is positioned corresponding to the inner edge of the rectangular rim reflector is characterized in that to block the transmission of light.

Then, with respect to the above configuration and manufacturing method will be described in detail with reference to the drawings. 2 is a perspective view of a first substrate and a second substrate of the transflective liquid crystal display according to the present invention, in which R, G, and B are one dot. As shown in the drawing, a reflector F having a reflector formed below and corresponding to the pixel region P is formed on the first substrate 110, and a transmissive part T from which a conductive material of the reflector is partially removed is formed. Further, on the second substrate 130, a color filter 133a formed between the black matrix 132 and the black matrix 132, an overcoat layer 134, a common electrode 135, and the like formed thereon are formed. . Of course, the upper portion includes a first alignment layer 136.

3 is a cross-sectional view illustrating the bonding of the first substrate and the second substrate shown in FIG. 2. As can be seen in the figure, the first substrate 110 and the second substrate 131 are arranged at a predetermined interval, the gate electrode 112a and the gate wiring (not shown) on the first substrate 110 below the Is formed on the same layer so as to block the transmission of light from the inside or the outside, corresponding to the boundary between the reflecting portion F and the transmissive portion T, which is formed to correspond to the pixel region in the future. The light blocking metal 112b is formed. Of course, the light blocking metal 112b is preferably formed of a material such as aluminum (Al) or molybdenum (Mo) as the same material as the gate wiring.

On the gate electrode 112a and the light blocking metal 112b, a gate insulating film 114 made of a silicon nitride film SiNx or a silicon oxide film SiOx is formed.

Next, the active layer 116 and the ohmic contact layers 118a and 118b are sequentially formed on the gate insulating layer 114, and the source and drain electrodes 120a and 120b are again formed on the ohmic contact layers 118a and 118b. The source and drain electrodes 120a and 120b together with the gate electrode 112a form a thin film transistor. Here, of course, as before, a data line (not shown) of a material such as the source and drain electrodes 120a and 120b is additionally formed on the gate insulating layer 114, and the data line is connected to the source electrode 120a and the gate The pixel area is defined by crossing the wiring.

Subsequently, a first passivation layer 122 made of an organic material is formed on the source and drain electrodes 120a and 120b to cover the thin film transistor. In addition, an uneven reflective plate 124 made of an opaque conductive material is formed at a portion corresponding to the pixel region on the first passivation layer 122. When the plane is substantially viewed, an etching process is performed in the center region. Through the above conductive material is removed. As a result, the concave-convex reflection plate 124 has a rectangular frame shape. This will be discussed later.

The second protective layer 126 is formed on the uneven reflective plate 124 again. The second protective layer 126 has a contact hole 121 exposing the drain electrode 120b together with the first protective layer 122.

A pixel electrode 128 made of a transparent conductive material is formed in the pixel area on the second protective layer 126, and the pixel electrode 128 is connected to the drain electrode 120b through the contact hole 121. . Of course, the pixel electrode 128 here serves as a transmission electrode. When the above process is completed, the first alignment layer 129 is subsequently formed.

On the other hand, a black matrix 130 is first formed on the second substrate 131, and then red (R), green (G), and blue (B) color filters are formed between the black matrices 130. 133a and 133b are sequentially formed repeatedly. Here, one color as well as the color filters 133a and 133b correspond to one pixel electrode 128, and the black matrix 130 covers edges of the thin film transistor and the pixel electrode 128.

An overcoat layer 134 is formed on the color filters 133a and 133b to protect and planarize the color filters 133a and 133b, and acrylic and polyimide resins are commonly used.

Next, a common electrode 135 made of a transparent conductive material is formed on the overcoat layer 134, and a second alignment layer 136 is formed on the common electrode 135.

The liquid crystal layer 140 is positioned between the first and second alignment layers 129 and 136. The liquid crystal used here is usually a twisted nematic liquid crystal, and the liquid crystal molecules of the liquid crystal layer 140 141 is arranged uniformly with a pretilt angle with respect to the substrate.

4 is a plan view of the cross-sectional view of FIG. 3 showing a unit pixel. Although briefly mentioned above, the reflecting portion F having the uneven reflective plate 124 formed at the lower side at the position corresponding to the pixel region P and the conductive portion of the uneven reflective plate 124 at the center thereof are formed. The transmissive part T from which the material is removed is formed, and as a whole, the reflecting plate 124 corresponding to the pixel area P has a rectangular frame shape. In addition, the light blocking metal 112b according to the present invention is formed on the reflective part F and the transmitting part T in a downward direction corresponding to the boundary part, which means that light leaks from an internal light source in the transmission mode. It will play the role of blocking.

Now, a method of manufacturing a transflective liquid crystal display device according to the present invention based on such a configuration will be described. First, as shown in FIG. 5A, a gate metal material 112 is deposited on a first substrate 110 such as a glass substrate or a quartz substrate by sputtering, and a photoresist 113 is formed on the gate metal material ( It is then applied onto 112 and then exposed using photo mask 115. Of course, the gate metal material 112 herein is preferably a metal material such as Al or Mo mentioned above.

Then, through development and etching, the gate electrode 112a and the light blocking metal 112b are formed as shown in FIG. 5B. Here, the light blocking metal 112b is the same material as the gate wiring (not shown), and the reflection part F from the external light corresponding to the pixel area to be formed later and the transmission part T from the internal light such as the backlight are shown. It is preferably formed at the boundary of.

As shown in FIG. 5C, a gate insulating layer 114 is formed on the gate electrode 112a and the light blocking metal 112b, and a semiconductor made of amorphous silicon is formed on the gate insulating layer 114. An ohmic contact layer made of n + amorphous silicon doped with a layer and phosphorus (P) is successively deposited and then patterned to form the active layer 116 of the thin film transistor.

Subsequently, a metal material is entirely deposited on the ohmic contact layer and the gate insulating layer 114, and then patterned to form source and drain electrodes 120a and 120b of the thin film transistor.

Thereafter, the ohmic contact layer exposed on the source and drain electrodes 120a and 120b is removed by an etching operation, and the exposed semiconductor layer is disposed on the source and drain 120a and 120b electrodes and the gate insulating layer 114. A first protective film 122 made of an inorganic material such as SiNx or SiO2, or an organic material such as benzocyclobutene (BCB) or acrylic, is formed on the first protective film 122 on the drain electrode 120b of the thin film transistor. It is removed by etching using a mask pattern to form contact holes (not shown).

In addition, as shown in FIG. 5D, the uneven reflective plate 124 is formed on the first passivation layer 122 formed at the portion corresponding to the pixel region. In other words, the uneven reflective plate 124 has two consecutive layers. It is formed as. In other words, an inorganic material such as SiNx or SiO 2 or an organic material such as BCB or acrylic is formed on the first protective film 122 and then patterned. An opaque metal layer such as a neodymium is deposited and then patterned to form a reflecting portion F in which the conductive material of the reflecting plate 124 is formed and a transmitting portion T from which the conductive material is removed, based on the unit pixel.

In addition, when the process of forming the reflective plate 124 is completed, the second passivation layer 126 and the pixel electrode 128 are subsequently formed, wherein the second passivation layer 126 is made of the same material as the first passivation layer 122. The pixel electrode 128 forms a reflective electrode formed on the reflective part F and a transmissive electrode formed on the transmissive part T. FIG.

However, in relation to the transflective liquid crystal display device and a method of manufacturing the same, a pixel area based on red (R), green (G), and blue (B) subpixels has been defined as an embodiment. The present invention further provides a semi-transmissive W + (White Pluse) liquid crystal display device defining a pixel area based on red (R), green (G), blue (B), and white (sub) pixels, and a manufacturing method thereof. Anything can be applied in relation to this.

Therefore, the transflective liquid crystal display device and the manufacturing method thereof according to the present invention, in the liquid crystal display device using the transflective mode, forms a light blocking metal again corresponding to the boundary of the reflecting portion and the transmissive portion corresponding to the pixel region; Above all, this process can be seen that the scope of the right extends to the liquid crystal display device formed on the same layer as the process of forming the gate electrode and the gate wiring.

As a result of the configuration up to now, the transflective liquid crystal display according to the present invention prevents light leakage occurring at the boundary between the reflecting portion F and the transmissive portion T formed on the lower side corresponding to the pixel region, thereby providing a high-quality liquid crystal display apparatus. Could be implemented.

Claims (6)

delete delete delete delete Providing a first substrate on which a pixel region is defined; Forming a gate wiring on the first substrate and forming a light blocking metal on the same layer as the gate wiring by using the same material as the gate wiring; Forming a gate insulating film on the first substrate on which the gate wiring and the light blocking metal are formed; Forming an active layer and a data line on the first substrate on which the gate insulating film is formed; Forming a first passivation layer on the first substrate on which the active layer and the data pattern are formed; Forming and patterning an inorganic or organic insulating material on the first protective film, and depositing and patterning an opaque conductive material thereon to form a laminated structure of a lower layer of the insulating material and an upper layer of the opaque conductive material, Forming a reflecting plate whose upper layer surface has an uneven shape; Forming a second passivation layer on the first substrate on which the reflective plate is formed; Forming a pixel electrode on the second passivation layer corresponding to the pixel region with a transparent conductive material; Bonding the second substrate to the first substrate at a predetermined interval from the first substrate; And Injecting liquid crystal between the first substrate and the second substrate, The reflective plate is positioned corresponding to the pixel area on the second passivation layer, and has a rectangular frame shape through which the area is removed to transmit light. The light blocking metal is positioned to correspond to the inner edge of the rectangular frame having a semi-transmissive liquid crystal display device, characterized in that the transmission of light. The method of claim 5, wherein the lower layer of the reflector is formed of an inorganic material of silicon nitride film (SiNx) or silicon oxide film (SiO ₂ ), or an organic material of benzocyclobutene (BCB) or acrylic, and the upper layer of the reflector is made of Al or AlNd. A method of manufacturing a transflective liquid crystal display device, characterized in that it is formed using an opaque metal layer of (Aluminum-Neodymium).

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