KR20060123915A - Method of manufacturing display substrate and display substrate using the same and display panel having the same - Google Patents

Abstract

A display substrate, a method for manufacturing the same, and a display panel having the same are provided to improve the brightness for a reflective area of the display panel and enhance the display quality of the display panel, by forming embossing patterns on an insulating layer in the reflective area. A switching element(TFT) is formed above a substrate(110), wherein the switching element is electrically connected to a gate line and a data line. An insulating layer(140) having a first pattern is formed above the switching element using a nozzle with a plurality of slits. A second pattern, in which embossing patterns are combined with the first pattern of the insulating layer, is formed on the insulating layer using an exposure mask with embossing patterns. A pixel electrode layer(150) is formed on the insulating layer, wherein the pixel electrode layer is electrically connected to the switching element. A reflective film(170) is formed on the pixel electrode layer.

Description

Method of manufacturing a display substrate, a display substrate and a display panel having the same by using the present invention TECHNICAL FIELD

1 is a cross-sectional view illustrating a display panel according to an exemplary embodiment of the present invention.

2 is a cross-sectional view schematically illustrating a display substrate according to a comparative example.

3A to 3E are diagrams schematically illustrating a method of manufacturing the display substrate illustrated in FIG. 2.

4 is a cross-sectional view schematically illustrating a display substrate according to an exemplary embodiment of the present invention.

5A through 5E are diagrams schematically illustrating a method of manufacturing the display substrate illustrated in FIG. 4.

6 is an exploded perspective view illustrating a display device according to an exemplary embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10: reflection-transmissive liquid crystal display panel 100: lower substrate

110, 410: transparent substrate 120, 420: TFT array layer

130, 430: passivation layer 140, 440: photosensitive insulating film

150 pixel electrode layer 160 buffer metal layer

170: reflecting film 180: planarization layer

200: liquid crystal layer 300: upper substrate

500. 600: PR nozzle part 510, 610: slit

520, 620: exposure mask 700: backlight assembly

The present invention relates to a method of manufacturing a display substrate, a display substrate and a display panel having the same, and more particularly, to a method of manufacturing a display substrate having improved display quality, a display substrate and a display panel having the same.

In general, the display device may be defined as a device that displays a predetermined image so that a user can recognize the data processed by the information processing device. Such display devices are widely used for small size, light weight, high resolution, and the like.

Liquid Crystal Display (Liquid Crystal Display) is one of the flat panel display device that displays the image using liquid crystal (Liquid Crystal), it is thinner and lighter than other flat panel display, and has the advantages of low driving voltage and low power consumption It is widely used throughout the industry.

The liquid crystal display device includes a liquid crystal display panel for converting a data signal to display an image. The liquid crystal display panel includes a lower substrate, an upper substrate facing the lower substrate, and a liquid crystal layer interposed between the lower substrate and the upper substrate to change light transmittance as an electrical signal is applied. The lower substrate is a substrate in which pixels consisting of a thin film transistor and a pixel electrode are formed in a matrix form, and the upper substrate is a substrate on which a common electrode facing the pixel electrode is formed.

The liquid crystal display panel further includes a color filter layer interposed between the lower substrate and the upper substrate. The color filter layer is composed of red, green, and blue color pixels (R, G, B).

The liquid crystal display panel included in the liquid crystal display may be classified into a reflection type and a transmission type according to a light source used.

The reflective liquid crystal display panel has an advantage of low power consumption because it receives natural light as a light source and reflects it. On the other hand, since it is influenced by the external environment, there is a disadvantage in that an image having high luminance cannot be obtained.

The transmissive liquid crystal display panel receives an artificial light from a light generating means provided inside the liquid crystal display as a light source and transmits the artificial light to obtain an image having high luminance. On the other hand, there is a disadvantage that the power consumption for driving the light generating means is large.

Accordingly, a reflection-transmissive liquid crystal display panel has been proposed to compensate for the disadvantages of the reflective and transmissive liquid crystal display panels, respectively, in order to obtain an image having a high luminance and to produce a liquid crystal display having low power consumption.

In the reflective-transmissive liquid crystal display panel, a method in which one pixel area is divided into a reflection area and a transmission area is designed. In this case, the transmissive region may guarantee a constant luminance by the light provided from the backlight assembly to the liquid crystal display panel. However, the reflecting region may have a reflectance changed according to the amount of external light or a path of incident light, thereby providing There is a problem that the luminance is lowered and, accordingly, the display quality of the liquid crystal display panel is lowered.

An object of the present invention for solving the above problems is to provide a method of manufacturing a display substrate that can improve the display quality by improving the brightness of the reflective region of the display panel.

Another object of the present invention is to provide a display substrate by the manufacturing method of the display substrate.

Another object of the present invention is to provide a display panel having the display substrate.

In order to achieve the above object, a method of manufacturing a display substrate according to an exemplary embodiment of the present invention includes forming a switching element connected to a gate line and a data line on a substrate, by using a nozzle having a plurality of slits on the switching element. Forming an insulating film having a first pattern, forming a second pattern obtained by synthesizing the embossed pattern on the first pattern using an exposure mask having an embossing pattern on the insulating film having the first pattern, and forming the second pattern Forming a pixel electrode layer electrically connected to the switching element on the patterned insulating layer, and forming a reflective film on the pixel electrode layer.

In this case, the sizes of the slits formed on the nozzle may be the same, or may be formed differently.

In addition, the intervals of the slits may be formed uniformly, or may be formed to have a random interval.

The first pattern includes a first region in which the insulating film is flat through the slit, and a second region in which a groove is formed adjacent to the first region.

The second pattern has a greater degree of bending of the embossing pattern formed in the second region than a degree of bending of the embossing pattern formed in the first region.

A display substrate for achieving another object of the present invention includes a switching element, a pixel electrode and a reflective film. The switching element is formed on a transparent substrate. The pixel electrode is connected to the switching element. The reflective film is formed on the pixel electrode and reflects light incident from the outside with a random embossing pattern.

The display substrate further includes an insulating film formed between the switching element and the pixel electrode, and the insulating film has the random embossing pattern.

The reflective film is formed in a partial region of the pixel electrode.

A display panel for achieving another object of the present invention includes an upper substrate and a lower substrate. The lower substrate is combined with the upper substrate to accommodate a liquid crystal layer and has a reflective film formed on an insulating film having a random embossing pattern to reflect front light.

The random embossing pattern includes random convex patterns and random concave patterns.

According to the manufacturing method of the display substrate, the display substrate and the display panel having the same, the reflective film is formed to have an irregular surface by an insulating film formed irregularly, and the reflectance can be increased to improve display quality.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view illustrating a display panel according to an exemplary embodiment of the present invention. In particular, a reflection-transmissive liquid crystal display panel is shown.

Referring to FIG. 1, the reflective-transmissive liquid crystal display panel 10 according to an embodiment of the present invention includes a lower substrate 100, a liquid crystal layer 200, and an upper substrate 300.

A thin film transistor (TFT) array layer 120 is formed on the lower substrate 100. The TFT formed in the TFT array layer 120 is defined by the gate electrode 121, the channel layer 123, the source electrode 124, and the drain electrode 125.

The gate electrode 121 extends from a gate wiring formed on the transparent substrate 110. In addition, the TFT array layer 120 includes the gate electrode 121 and a gate insulating layer 122 made of a material such as silicon nitride (SiNx) to cover the gate wiring and the gate electrode 121.

The gate wiring or the gate electrode 121 may be formed of an aluminum-based metal such as aluminum (Al) or an aluminum alloy, a silver-based metal such as silver (Ag) or a silver alloy, or a copper-based such as copper (Cu) or a copper alloy. Metal, molybdenum-based metals such as molybdenum (Mo) or molybdenum alloy, etc., made of a metal such as chromium (Cr), tantalum (Ta) or titanium (Ti).

The channel layer 123 covers the gate electrode 121, and includes a semiconductor layer such as a-Si and a semiconductor impurity layer such as n + a-Si formed on the semiconductor layer.

The source electrode 124 covers a portion of the channel layer 123. The drain electrode 125 covers a portion of the channel layer 123 and is spaced apart from the source electrode 124 by a predetermined interval.

The source electrode 124 or the drain electrode 125 may be formed of an aluminum-based metal such as aluminum (Al) or an aluminum alloy, or a silver-based metal such as silver (Ag) or a silver alloy, such as copper (Cu) or a copper alloy. It is made of a copper-based metal, molybdenum-based metals such as molybdenum (Mo) or molybdenum alloy, and a metal such as chromium (Cr), tantalum (Ta) or titanium (Ti).

In addition, the gate electrode 121 or the source electrode 124 may be formed as a single layer or a double layer. When formed as the single layer, it may be formed of a metal such as aluminum (Al), aluminum (Al) -neodymium (Nd) alloy, copper (Cu), etc., and when formed as the double layer, chromium (Cr) and molybdenum Materials having excellent physical / chemical properties, such as (Mo) or molybdenum alloy films, are formed in the lower layer, and materials having low resistivity, such as aluminum (Al) or aluminum alloy, are formed in the upper layer.

The lower substrate 100 further includes a passivation layer 130, a photosensitive insulating layer 140, and a pixel electrode layer 150.

The passivation layer 130 may cover the TFT to expose a portion of the drain electrode 125 and to protect the channel layer 123 between the source electrode 124 and the drain electrode 125.

The photosensitive insulating layer 140 has an embossed pattern having a plurality of irregularities formed on a surface thereof and exposes a portion of the drain electrode 125 while covering the passivation layer 130. A detailed description of the embossing pattern will be described in detail with reference to FIGS. 2 to 5E.

The pixel electrode layer 150 covers the photosensitive insulating layer 140 and the transmission area TA and is electrically connected to each other via the drain electrode 125 and the contact hole CNT of the TFT. Here, the transmission area TA is an area for displaying an image using the back light transmitted from the back of the liquid crystal display panel 10.

In addition, the lower substrate 100 may further include a buffer metal layer 160, a reflective film 170, and a planarization layer 180.

The buffer metal layer 160 is formed to reduce contact resistance with the pixel electrode layer 150 of indium tin oxide (ITO) or indium zinc oxide (IZO) components, and the reflective region RA of the lower substrate 100. It is formed correspondingly. The buffer metal layer 160 includes molybdenum tungsten (MoW). The reflection area RA is an area for displaying an image using front light provided from the front surface of the liquid crystal display panel 10.

In FIG. 1, the buffer metal layer 160 covering the pixel electrode layer 150 corresponding to the reflective region RA is employed. However, the lower substrate 100 may be formed by omitting the buffer metal layer 160. have.

The reflective film 170 is formed in the reflective area RA of the liquid crystal display panel 10 while covering the TFT on the buffer metal layer 160.

Since the pixel electrode layer 150, the buffer metal layer 160, and the reflective film 170 are formed on the photosensitive insulating layer 140, the pixel electrode layer 150, the buffer metal layer 160, and the reflective layer 170 are formed to have an embossing pattern corresponding to the embossing pattern formed on the photosensitive insulating layer 140.

The planarization layer 180 is formed on the reflective film 170 and has a flat surface while covering the reflective area RA and the transmission area TA. The planarization layer 180 is preferably made of a material having excellent light transmittance, such as the photosensitive insulating layer 140 for transmitting light.

The photosensitive insulating layer 140 is preferably made of a material having a material transmittance of 90% or more in the visible light region, and the material of the photosensitive insulating layer 140 and the material of the planarization layer 180 are preferably the same. The thickness of the planarization layer 180 is sufficient to planarize the embossing pattern of the reflective film 170.

Meanwhile, the upper substrate 300 includes a light blocking layer (not shown) that partitions a unit pixel region on the transparent substrate 310, a color pixel layer 320 formed in the unit pixel region, and the color pixel layer 320. The over coating layer 330 formed thereon and the common electrode layer 340 formed on the over coating layer 330 are included. The color pixel layer 320 and the light blocking layer may be formed on the lower substrate 100.

Herein, the manufacturing method of the display panel 10 in which the photosensitive insulating layer 140 is formed is as follows.

2 is a cross-sectional view schematically illustrating a display panel according to a comparative example, and FIGS. 3A to 3E are diagrams schematically illustrating a method of manufacturing the display panel shown in FIG. 2. In particular, the formation process of the photosensitive insulating film shown in FIG. 2 is shown.

2, the TFT array layer 420, the passivation layer 430, and the photosensitive insulating layer 440 are sequentially formed on the lower substrate 400 of the display panel according to the comparative example.

The TFT array layer 420 and the passivation layer 430 are formed in the same manner as the TFT array layer 120 and the passivation layer 130 shown in FIG. 1, and a detailed description thereof will be omitted.

In addition, a pixel electrode layer, a buffer metal layer, and a reflective layer are formed on the photosensitive insulating layer 440 on the lower substrate 400 in the same manner as shown in FIG. 1. Therefore, detailed description thereof will be omitted.

The photosensitive insulating layer 440 has an embossed pattern having irregularities on the surface thereof. This means that a reflective film (not shown) formed in a shape corresponding to that of the photosensitive insulating film 440 has the embossed pattern.

The reflective film having the embossed pattern may reflect light incident at various angles, thereby improving the reflectance of the reflective region RA in which the reflective film is formed. This may improve the luminance of the reflective area RA and may improve display quality of the liquid crystal display panel.

Referring to Figures 2 to 3E, the manufacturing method of the photosensitive insulating film according to the comparative example is as follows.

After forming the thin film transistor (TFT) array layer 420 on the transparent substrate 410 included in the lower substrate 400, and after forming the passivation layer 430 on the TFT array layer 420 An insulating film 440 is coated.

The photosensitive insulating layer 440 is formed by a photo resist process. First, a liquid PR reacting when light of a specific wavelength band is irradiated is coated on the transparent substrate 410 through the PR slit 510.

As shown in FIG. 3A, the PR slit 510 has a predetermined width and is formed in the length direction of the PR nozzle 500. The liquid PR is sprayed through the PR slit 510, and a PR coating is made on the entire surface of the transparent substrate 410 with a uniform thickness (FIG. 3B).

Thereafter, an exposure mask 520 is disposed on the PR-coated transparent substrate 410, and an exposure process of irradiating light is performed (FIG. 3C). In this case, an embossing pattern having a predetermined shape is formed in the exposure mask 520 to form irregularities in the photosensitive insulating layer 440. Therefore, a constant light is irradiated to the PR of the area corresponding to the embossing pattern.

The area irradiated with light through the exposure process performed on the coated PR is removed through the development process (FIG. 3D). Since the embossing pattern having a predetermined shape is formed in the exposure mask 520, the PR having the developing process is provided with irregularities having a predetermined shape corresponding to the embossing pattern formed in the exposure mask 520.

The photosensitive insulating film 440 having an embossed pattern having a predetermined shape is formed by performing a baking process to reinforce the structure of the PR weakened in the developing process in the PR having the developing process (FIG. 3E).

In this case, since the embossed pattern formed on the photosensitive insulating layer 440 is formed in a certain shape, the pattern of the embossed pattern is formed regularly. That is, an embossing pattern having irregularities of the same size and shape is formed.

In the liquid crystal display panel having the photosensitive insulating film 440 formed by the above method, the reflective film in the reflective region is formed in the embossing pattern along the irregularities and the reflectance is improved compared to the liquid crystal display panel having the photosensitive insulating film in which the unevenness is not formed. Luminance improvement can be obtained. However, the embossing pattern that is regularly formed, that is, the embossing pattern having irregularities having the same shape and size, has a low luminance improvement due to the monotonous shape.

4 is a cross-sectional view schematically illustrating a display panel according to an exemplary embodiment of the present invention, and FIGS. 5A to 5E are schematic views illustrating a manufacturing method of the display panel shown in FIG. 4. admit. In particular, a method of forming the photosensitive insulating film shown in FIG. 4 is shown.

FIG. 4 is an extract of a portion of the lower substrate shown in FIG. 1. Therefore, the same components as those of the lower substrate shown in FIG. 1 will be used.

That is, the lower substrate 100 is sequentially disposed on the transparent substrate 110, the TFT array layer 120, the passivation layer 130, the photosensitive insulating layer 140, the pixel electrode layer 150, the buffer metal layer 160, and the reflective film ( 170 and the planarization layer 180 are formed. Therefore, detailed description thereof will be omitted.

An embossing pattern having irregularities having irregular shapes is formed in the photosensitive insulating layer 140. This means that a reflective film (not shown) formed in a shape corresponding to that of the photosensitive insulating layer 140 has the embossing pattern. The reflective film having the embossed pattern may reflect light incident at various angles, thereby improving the reflectance of the reflective region RA in which the reflective film is formed. This can improve the luminance of the reflective area RA and improve the display quality of the liquid crystal display panel.

In addition, as the irregular reflective film is formed as compared to the reflective region RA of the liquid crystal display panel illustrated in FIG. 2, the luminance characteristic of the reflective region may be improved by reflecting front light incident at more various angles.

4 to 5E, the method of manufacturing the photosensitive insulating layer 140 will be described below.

After forming the thin film transistor (TFT) array layer 120 on the transparent substrate 110 included in the lower substrate 100, and forming the passivation layer 130 on the TFT array layer 120, a photosensitive insulating film ( 140).

The photosensitive insulating layer 140 is formed by a photo resist process. First, when light of a specific wavelength band is irradiated, the liquid PR reacting is coated on the transparent substrate 110 through a PR nozzle (nozzle, 600).

As shown in FIG. 5A, a plurality of PR slits 610 having a predetermined width and length are formed in the PR nozzle 600. The PR slits 610 may be formed to have the same size or may be formed to have different sizes. Similarly, the intervals between adjacent slits among the slits 610 may be formed at equal intervals or may be formed at differential intervals.

Liquid PR is sprayed through the PR nozzle 600 in which the slits 610 are formed, and PR coating is performed on the transparent substrate 110 at a position corresponding to the slits 610. At this time, on the transparent substrate 110 corresponding to the distance between the slits 610 adjacent to each other, the liquid PR injected in a position corresponding to the slits 610 flows to have a groove 611 of irregular depth. The first pattern is formed (FIG. 5B).

That is, the liquid PR is injected to a position corresponding to the slits 610 so that the PR of the liquid flows to a position corresponding to the interval between the slits 610 in a state in which the PR coating is made to have a uniform height. The first pattern of the photosensitive insulating layer 140 having different heights is formed.

Subsequently, an exposure mask 620 is disposed on the PR-coated transparent substrate 410, and an exposure process of irradiating light is performed (FIG. 5C). At this time, since the embossing pattern (not shown) having a predetermined shape is formed in the exposure mask 620, light of a constant amount of light is irradiated to the PR of the region corresponding to the embossing pattern.

The area irradiated with light through the exposure process performed on the coated PR is removed through the development process (FIG. 5D). In this case, irregularities having a shape corresponding to the embossing pattern are formed in the PR by the embossing pattern formed on the exposure mask 620.

That is, a region in which light is irradiated selectively by the embossing pattern of the exposure mask 620 on the first pattern of the PR having the grooves 611 is removed, thereby synthesizing the first pattern and the embossing pattern. A pattern is formed. The second pattern has a groove 612 having a depth deeper than the periphery when the embossing pattern corresponds to the groove 611.

A photosensitive insulating film 140 having an embossed pattern having irregular irregularities is formed by performing a baking process to strengthen the structure of the PR weakened in the developing process on the PR on which the developing process is performed (FIG. 5E). ).

The embossing pattern of the photosensitive insulating layer 140 formed by the above method may form an embossing pattern increased more than twice as much as the embossing pattern illustrated in FIG. 2. Since the embossed pattern formed in the reflective region RA has a random shape, the reflective film formed on the photosensitive insulating layer 140 also has a random shape.

Therefore, when the photosensitive insulating layer 140 is formed according to the manufacturing method of the display panel according to the exemplary embodiment of the present invention, the reflectance of the display panel having the photosensitive insulating layer shown in FIG. The overall brightness of the liquid crystal display panel can be improved.

6 is an exploded perspective view illustrating a display device according to an exemplary embodiment of the present invention.

Referring to FIG. 6, the liquid crystal display device 1000 according to the exemplary embodiment includes a liquid crystal display panel 10 and a backlight assembly 700.

Since the liquid crystal display panel 10 has the same configuration as the liquid crystal display panel described with reference to FIGS. 1 and 4 to 5e, detailed descriptions thereof will be omitted.

The backlight assembly 700 includes a lamp unit 710, a light guide plate 720, a diffusion sheet 730, a light collecting sheet 740, and a reflecting plate 750.

The lamp unit 710 includes a lamp 711 for generating light and a lamp cover 712 for covering the lamp 711 and reflecting the light in the direction of the light guide plate 720.

The light guide plate 720 has a rectangular plate shape to guide the light provided from the lamp unit 710 toward the display panel 10. The lamp unit 710 is disposed adjacent to any one side of the plurality of side surfaces of the light guide plate 720 to receive the light.

Light incident on the light guide plate 720 is emitted in an upper surface of the light guide plate 320 of the light guide plate 720, that is, in a direction disposed on the liquid crystal display panel 10.

The diffusion sheet 730 is provided on the light guide plate 720 to diffuse the light emitted from the light guide plate 720 to improve the uniformity of the brightness of the light emitted from the light guide plate 720.

The light collecting sheet 740 is provided on the diffusion sheet 730 to collect light diffused by the diffusion sheet 730.

The light collecting sheet 740 has a plurality of first prism patterns extending in a first direction D1 to collect the light, and a first prism sheet 741 and a second direction different from the first direction D1. A plurality of second prism patterns extending to (D2) are formed to form a second prism sheet 742 that condenses the light.

The reflective plate 750 is provided under the light guide plate 720 to reflect the light leaked from the lower surface of the light guide plate 720 toward the light guide plate 720. Thus, the reflector plate 750 improves the light efficiency of the backlight assembly 700.

According to the present invention as described above, by forming an irregular embossing pattern in the reflective region of the display panel, it is possible to improve the display quality of the display panel while improving the luminance of the reflective region.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (12)

Forming a switching element connected to the gate wiring and the data wiring on the substrate; Forming an insulating film having a first pattern by using a nozzle having a plurality of slits on the switching element; Forming a second pattern obtained by synthesizing the embossed pattern on the first pattern by using an exposure mask having an embossed pattern on the insulating layer having the first pattern; Forming a pixel electrode layer electrically connected to the switching element on the insulating layer on which the second pattern is formed; And And forming a reflective film on the pixel electrode layer. The method of claim 1, wherein the slits have the same size. The method of claim 1, wherein the slits have different sizes. The method of claim 1, wherein the intervals of the slits are uniform. The method of claim 1, wherein the intervals of the slits are random. The display substrate of claim 1, wherein the first pattern comprises a first region in which the insulating layer is flat through the slit, and a second region in which a groove is formed adjacent to the first region. Way. The method of claim 6, wherein the second pattern has a greater degree of bending of the embossing pattern formed in the second region than a degree of bending of the embossing pattern formed in the first region. A switching element formed on the transparent substrate; A pixel electrode connected to the switching element; And And a reflective film formed on the pixel electrode and reflecting light incident from the outside with a random embossing pattern. The semiconductor device of claim 8, further comprising an insulating film formed between the switching element and the pixel electrode. And the insulating film has the random embossing pattern. The display substrate of claim 8, wherein the reflective film is formed in a portion of the pixel electrode. An upper substrate; And And a lower substrate coupled to the upper substrate to accommodate a liquid crystal layer and having a reflective film formed on an insulating film having a random embossing pattern to reflect front light. The display panel of claim 11, wherein the random embossing pattern comprises random convex patterns and random concave patterns.

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