KR20060133766A - Black matrix and method for forming the black matrix of a substrate in a lcd, and a substrate and method for forming the substrate in the lcd - Google Patents

Abstract

A substrate for an LCD, a method for manufacturing the substrate, and a method for manufacturing the LCD are provided to increase the contact area between a spacer and a substrate, thereby reducing the stress applied to the spacer, by forming a black matrix to have a concave portion. A black matrix(215) is placed on a substrate(211). The black matrix has a first surface contacted with the substrate and a second surface opposite to the first surface, wherein the second surface is a larger area than the first surface. A transparent electrode(213) is placed on the black matrix. A spacer(23) is placed on the transparent electrode correspondingly to the black matrix. The second surface of the black matrix has a concave portion(216), and the spacer is placed on the concave portion of the black matrix.

Description

BLACK MATRIX AND METHOD FOR FORMING THE BLACK MATRIX OF A SUBSTRATE IN A LCD, AND A SUBSTRATE AND METHOD FOR FORMING THE SUBSTRATE IN THE LCD}

1 is a schematic cross-sectional view of a typical liquid crystal display device;

FIG. 2 is a cross-sectional view of a color filter substrate of the liquid crystal display of FIG. 1; FIG.

3 is a schematic view of a liquid crystal display according to an embodiment of the present invention;

4 is a schematic view of a color filter substrate of a liquid crystal display according to an exemplary embodiment of the present invention;

5 to 9 illustrate a method of forming a substrate of a liquid crystal display according to an exemplary embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

21: first substrate 25: second substrate

211 and 251: transparent substrate 213: common electrode

22, 216: recess 23: spacer

27: liquid crystal layer 215: black matrix

217: color filter array 253: pixel electrode

219: buffer film 29: exposure mask

293: shading pattern 297: slit pattern

The present invention relates to a liquid crystal display device, and more particularly, to a black matrix of a liquid crystal display device, a method of forming the same, and a substrate of the liquid crystal display device and a method of forming the same.

Recently, as the demand for portable electronic products such as notebook computers and mobile phones increases, the demand for thin and light flat panel displays (FPDs) increases. A flat panel display (FPD) is a display device that provides a thin and flat screen, and is typically used as a liquid crystal display device (LCD) or a large digital TV (TV) that is widely used as a computer monitor. Such as a plasma display (PDP) or an organic light emitting display (OELD) used in a mobile phone. Among flat panel displays, in particular, liquid crystal displays have been widely used in recent years because they are lighter, smaller in volume, and operate with smaller power than other display devices having the same screen size.

The liquid crystal display transmits an image by converting an input electric signal into visual information by using a characteristic in which light transmittance of a liquid crystal, which is an intermediate state material between a liquid and a crystal, changes according to an applied voltage. That is, a conventional liquid crystal display device is composed of two substrates provided with transparent electrodes and liquid crystal injected between the two substrates. Different voltages are applied to the two substrates to apply an electric field to the liquid crystal, and at this time, the light transmittance is changed as the arrangement of the liquid crystal molecules is changed.

1 is a schematic cross-sectional view of a typical liquid crystal display. Referring to FIG. 1, a typical liquid crystal display device includes a color filter substrate 1 and a transistor array substrate 2 bonded to upper and lower portions, and a liquid crystal layer 3 by liquid crystal injected between these substrates 1 and 2. It consists of. The color filter substrate 1 and the transistor array substrate 2 are provided with a common electrode 4 and a pixel electrode 5, respectively. A reference voltage is applied to the common electrode 4 and a data voltage is applied to the pixel electrode 5. When the reference voltage and the data voltage are applied to the common electrode 4 and the pixel electrode 5, respectively, the arrangement of the liquid crystal molecules is changed and thus the light transmittance of the light to the liquid crystal molecules is changed. Therefore, the electric signal input to the pixel electrode 5 is changed into visual information, and thus the image is transmitted.

The gap between the color filter substrate 1 and the transistor array substrate 2 is usually called a cell gap. Cell spacing affects the overall operating characteristics of the liquid crystal display, such as contrast ratio, viewing angle, and luminance uniformity, and should be kept constant. Therefore, the spacer 6 is formed between the color filter substrate 1 and the transistor array substrate 2 so as to keep the cell gap constant.

FIG. 2 is a partial cross-sectional view of the color filter substrate 2 of the liquid crystal display of FIG. 1. As shown in the figure, the color filter substrate 2 comprises a transparent substrate 11; A black matrix 12 and a color filter 13 formed on the transparent substrate 11; A planarization film 14 formed on the black matrix 12 and the color filter 13; It consists of the transparent electrode 15 formed on the planarization film 14. The spacer 5 is a column spacer, which is formed in an aspect ratio display area that does not affect the aperture ratio of the liquid crystal display panel, and is formed on the black matrix 12. The general manufacturing process of such a typical color filter substrate will be briefly described as follows. First, a black matrix 12 made of a resin or a metal material for blocking unnecessary light is formed on a substrate 11 made of a transparent insulating material such as glass, and then a color filter is formed in an image display area between the black matrices. (13) is formed. In addition, a planarization film 14 is formed on the substrate 11 including the color filter 13 to prevent pigment ion elution and a transparent electrode 15 is formed. In this case, a spacer 5 for maintaining cell spacing is formed on the black matrix 12, which is the image non-display area, by using a photosensitive resist to expose, develop, and bake.

 As is well known, the stress σ is inversely proportional to the area A of the contact surface and proportional to the pressure P. Therefore, in order to minimize the stress applied to the spacer, it is required to increase the contact area between the spacer and the upper surface of the color filter substrate bonded thereto. In addition, in order to increase the bonding force between the spacer and the color filter substrate, it is also required to increase the contact area between the spacer and the upper surface of the color filter substrate bonded thereto. The smaller the contact area between the spacer and the color filter substrate, the greater the likelihood that the spacer will fall away from the color filter substrate and the stress the spacer receives. Deviation of the spacers and an increase in the stresses the spacers make it difficult to keep the cell gap constant.

  However, the black matrix 12 of the typical color filter substrate 2 of FIG. 2 has a flat upper surface, whereby the upper surface of the color filter substrate 2 to which the spacer 5 is coupled is also flattened. This makes the contact surface between the spacer 5 and the color filter substrate 2 flat, thus according to the typical color filter substrate 2 and its black matrix 12 structure, the spacer 5 and the color filter substrate 2 The contact area between them is bound to be limited.

The present invention has been devised in consideration of at least the above-described situation, and an object thereof is to provide a black matrix, a method of forming the same, a substrate of the liquid crystal display device using the same, and a method of forming the same.

Exemplary embodiments of the present invention for achieving the object of the present invention provides a method of forming a black matrix of a substrate for a liquid crystal display device. The black matrix forming method comprises: forming an opaque film and a photosensitive film for black matrix on a substrate; Exposing and developing the photosensitive film using an exposure mask having a light shielding portion, an exposure portion and a partial exposure portion having different exposure intensities to form a photosensitive film pattern; The etching of the opaque film may be performed by using the photoresist pattern as an etching mask.

In the method, the black matrix has recesses because the exposure intensities of the light blocking portion, the exposure portion, and the partial exposure portion are different from each other. For example, the exposure intensity is in the order of the light blocking portion, the exposure portion and the partial exposure portion. At this time, the black matrix has the concave portion at a position corresponding to the partial exposure portion.

Exemplary embodiments of the present invention for achieving the object of the present invention provides a method for forming a substrate for a liquid crystal display device. The forming method includes: forming a black matrix having recesses on a substrate; And forming a spacer at a position corresponding to the recess.

The concave portion may exhibit various shapes, for example, may be hemispherical.

In one embodiment of the method of forming a substrate for a liquid crystal display device, forming the black matrix having the concave portion comprises: forming an opaque film and a photosensitive film on the substrate; Exposing and developing the photosensitive film using an exposure mask having a light shielding portion, an exposure portion separated by the light shielding portion, and a partial exposure portion in the exposure portion to form a photosensitive film pattern; The etching of the opaque film may be performed by using the photoresist pattern as an etching mask.

In example embodiments, the method may further include forming a color filter and a transparent electrode before forming the spacer.

Exemplary embodiments of the present invention for achieving the object of the present invention provides a substrate for a liquid crystal display device. The substrate for a liquid crystal display device comprises: a black matrix on the substrate, the first surface in contact with the substrate and the second surface not in contact with the substrate, the second surface having a larger area than the first surface; A transparent electrode placed on the black matrix; And a spacer disposed on the transparent electrode so as to correspond to the black matrix.

In one embodiment of the substrate for the liquid crystal display device, the black matrix has a recessed portion on the second surface, and the spacer is disposed corresponding to the recessed portion.

In one embodiment of the substrate for a liquid crystal display device, the liquid crystal display may further include a buffer layer disposed between the transparent electrode and the black matrix.

Exemplary embodiments of the present invention for achieving the object of the present invention provides a substrate for a liquid crystal display device. The liquid crystal display substrate includes: a black matrix formed on the substrate at regular intervals and having recesses; A color filter array covering a substrate between the black matrices and covering a portion of the black matrix; A transparent electrode disposed on the black matrix and the color filter array; And a spacer disposed on the transparent electrode so as to correspond to the recess of the black matrix.

Exemplary embodiments of the present invention for achieving the object of the present invention provides a method of manufacturing a liquid crystal display device. A method of manufacturing the liquid crystal display device includes: providing a first substrate having a recessed portion on a surface thereof; Providing a second substrate; Forming a spacer in the recess; Bonding the first substrate and the second substrate through the spacers; And injecting a liquid crystal between the first substrate and the second substrate.

In the method of manufacturing the liquid crystal display device, providing the first substrate comprises: forming a black matrix having a recess corresponding to a recess of the first substrate on a transparent substrate; And forming a transparent electrode on the black matrix and the transparent substrate.

The above objects, other objects, features and advantages of the present invention will be readily understood through the following various embodiments related to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosure may be made thorough and complete, and to fully convey the spirit of the invention to those skilled in the art. Like numbers refer to like elements throughout.

 In the drawings, the thicknesses of layers and regions are exaggerated for clarity. In addition, where a layer is said to be "on" another layer or substrate, it may be formed directly on the other layer or substrate, or a third layer may be interposed therebetween. Like numbers refer to like elements throughout.

In addition, in various embodiments of the present specification, terms such as first, second, and third are used to describe various regions, films, substrates, and the like, but these regions, films, and substrates are defined by these terms. It should not be. In addition, these terms are only used to distinguish any given region, film, or substrate from other regions, film, or substrate.

The present invention relates to a liquid crystal display device, but may have various excellent characteristics provided by the present invention, but in particular, a color filter substrate and a method of forming the same, which can significantly lower the stress between the spacer and the color filter substrate and the stress applied to the spacer. To provide. One embodiment of the present invention in particular allows the upper surface of the color filter substrate to have recesses by adopting a black matrix structure with recesses, unlike conventional black matrices which typically have a flat upper surface. In other words, the concave portion of the black matrix is transferred to the upper surface of the color filter substrate engaging with the spacer. The concave portion can exhibit, for example, a hemispherical shape or the like, and the concave portion is not limited thereto. The recess may refer to any shape recessed to have a larger area relative to the flat surface.

3 is a schematic view of a liquid crystal display according to an exemplary embodiment of the present invention. According to an exemplary embodiment of the present invention, a liquid crystal display device includes a first substrate 21 and a second substrate 25, a liquid crystal layer 27 by liquid crystal injected between the two substrates 21 and 25, and two substrates. And a spacer 23 for keeping the gap between the 21 and 25 constant. According to the present invention, at least one of the two substrates of the liquid crystal display device, for example, the upper surface of the first substrate 21 has a recess 24. The recessed portion 24 may take a variety of forms and may be, for example, hemispherical. For example, the first substrate 21 may be a substrate on which the common electrode is formed, and the second substrate 25 may be a substrate on which the pixel electrode is formed. The first substrate 21 has a recess 22, and the spacer 23 is coupled to the recess 24. Therefore, according to the present invention, the contact surface between the spacer 23 and the substrate 21 is changed into a hemispherical shape so that the stress applied to the spacer 23 is reduced, and the bonding force between the spacer 23 and the first substrate 21 is increased. Exhibits an excellent effect.

The first substrate 21 includes a transparent substrate 211 and a transparent electrode 213 used as a common electrode. The second substrate 25 includes a transparent substrate 251 and a pixel electrode 253.

According to an embodiment of the present invention, the recess 24 of the first substrate 21 is due to the black matrix. This will be described with reference to FIG. 4. 4 schematically shows a first substrate 21 according to an embodiment of the present invention.

Referring to FIG. 4, the first substrate 21 according to an embodiment of the present invention is formed on the substrate 211 at a predetermined interval and has a black matrix 215 having a recess 216 and a black matrix 215. The color filter array 217 covering the substrate between and covering a part of the black matrix, the transparent electrode 213 disposed on the black matrix 215 and the color filter array 217, and the concave of the black matrix 215 The spacer 23 may be disposed on the transparent electrode 213 to correspond to the portion 216. Typically, the substrate on which the color filter array 217 is formed is called a color filter substrate. Therefore, unless otherwise specified in the embodiments to be described later, the color filter substrate referred to refers to the substrate on which the color filter array is formed.

The black matrix 215 is formed of a resin or the like, and has a recess 216 at the center thereof, for example. The recess 216 of the black matrix 215 is transferred to the transparent electrode 213, and the spacer 23 is coupled to the recess 22 of the transparent electrode 213.

The transparent electrode 213 may be formed of a transparent conductive film such as tin indium oxide (ITO) or zinc indium oxide (IZO), and a buffer film 219 may be further disposed thereunder. The buffer film 219 is made of a material such as polyimide.

The color filter array 217 is a color layer 217R of a red layer / green layer / blue layer (or three primary colors of yellow (Y), magenta (M), and cyan (C)), which is used to realize color, and implements color. , 217G, 217B are alternately arranged for each pixel area.

As shown in FIG. 4, the color filter array 217 is mainly formed on the upper substrate (color filter array substrate) 21 of the two substrates bonded on the upper and lower sides of the liquid crystal. However, the color filter array 217 may be arranged to be inconsistent with the pixel area due to a mis-assembly between two substrates. To prevent this, the color filter array is disposed on the transistor array substrate (reference numeral 25 in FIG. 3). It may be formed in. The presence of the color filter array on the substrate 21 does not affect the formation of the recess 216 of the black matrix 215 and thus the recess 22 of the substrate 21.

A method of forming the color filter array substrate illustrated in FIG. 4 according to an embodiment of the present invention will now be described with reference to FIGS. 5 to 9. Only the black matrix having a hemispherical shape in the concave portion will be described in an exemplary embodiment.

First, FIGS. 5 to 7 will be described with reference to a method of forming a black matrix. Referring to FIG. 5, an opaque film 215A for forming a black matrix is formed on the substrate 211. The substrate 211 is made of a transparent insulating material. The black matrix opaque film 215A may be formed of a metal such as chromium and its oxide, a metal oxide, or an organic material. A photoresist film 216A, for example, is formed on the black matrix opaque film 215A as a photosensitive film.

An exposure process and a development process are performed on the substrate 211 on which the opaque film 215A for the black matrix and the photosensitive film 218A are formed by using the exposure mask 29, and the concave portion 218r as shown in FIG. A photosensitive film pattern 218 having a shape is formed.

The exposure mask 211 includes a light blocking pattern 293 and a slit pattern 297 made of a material that blocks light transmission, such as chromium, on a transparent substrate 291 such as quartz. Light is not transmitted through the light shielding pattern 293 to form a light shielding area. An exposure area 295 through which light is transmitted is formed between the light shielding patterns 293. The slit pattern 297 is formed in the light transmission region 295 and forms a partial exposure region.

The degree of light transmission through the light shielding pattern 293, the slit pattern 297 and the light transmission region 295 occurs, and the transmission intensity is the light transmission region 295, the slit pattern 297 and the light shielding pattern ( 293) in order. Instead of the slit pattern 297, a half-tone exposure may be used that applies a single pattern to the partial exposure area as a material having a higher light transmittance than the light shielding pattern 293.

The portion of the photosensitive film 218A corresponding to the light transmissive region 295 is exposed to high concentration of light and remains after development without being removed. However, since the portion of the photosensitive film 218A corresponding to the light shielding region that is the light shielding pattern 293 is not exposed, it is removed after development. On the other hand, a portion of the photosensitive film 218A corresponding to the partial exposure region, which is the slit pattern 297, is exposed to light having a lower concentration than the exposure region 295, and remains a certain thickness. As a result, the photosensitive pattern 218 has a recess 218r in a portion corresponding to the slit pattern 297.

The photosensitive film described herein is described as an example of a negative photosensitive film in which a portion not receiving light is removed. However, a positive photosensitive film may be used in which the lighted portion is removed. In this case, the exposure mask may have a slit pattern in the light blocking area, and the exposure area may be formed outside the light blocking area.

Referring to FIG. 7, the black matrix 215 having the recess 216 is formed by etching the opaque film 215A for the black matrix using the photosensitive pattern 218 as an etching mask. According to this embodiment, the black matrix 215 having the concave portion 216 is formed in one photographic process.

Referring to FIG. 8, the color filter array 217 is formed in a well known manner. The color filter array 217 is formed at a position corresponding to the pixel electrode to implement color. The buffer film 219 and the common electrode 213 made of a transparent material are formed on the color filter array 217 and the black matrix 215. The recess 216 of the black matrix 215 is transferred to the transparent electrode 213 so that the transparent electrode 213 also includes the recess 22.

Referring to FIG. 9, a spacer 23 is formed in the recess 22 of the transparent electrode 213. The spacer 23 may be formed by, for example, applying a photolithography process of coating, exposing, developing, and etching an organic material having high strength.

After fabricating the substrate on which the pixel electrode is formed, the substrate is bonded to the above-described black matrix formed substrate, and then the liquid crystal is injected and sealed to complete the liquid crystal display device.

The above-described embodiments are intended to illustrate the best state in carrying out the present invention, the use of other inventions such as the present invention in other state known in the art, and the specific fields of application and uses of the invention. Various changes are possible. Accordingly, the detailed description of the invention is not intended to limit the invention to the disclosed embodiments. Also, the appended claims should be construed as including other embodiments.

According to the present invention, the black matrix has recesses, so that the contact area between the spacer and the substrate is increased, so that the stress applied to the spacer is reduced and the possibility of the spacer being released from the substrate is lowered. Therefore, the cell gap can be kept constant in the liquid crystal display device, thereby forming a reliable liquid crystal display device.

Claims (10)

A black matrix disposed on a substrate and having a first surface in contact with the substrate and a second surface not in contact with the substrate, wherein the second surface has a larger area than the first surface; A transparent electrode on the black matrix; And, And a spacer disposed on the transparent electrode so as to correspond to the black matrix. The method of claim 1, And the black matrix has a concave portion on the second surface, and the spacer is disposed corresponding to the concave portion of the black matrix. The method according to claim 1 or 2, And a buffer layer disposed between the transparent electrode and the black matrix. A black matrix formed on the substrate at regular intervals and having recesses; A color filter array covering a substrate between the black matrices and a portion of the black matrix; A transparent electrode disposed on the black matrix and the color filter array; And, And a spacer disposed on the transparent electrode so as to correspond to the recess of the black matrix. Forming an opaque film and a photosensitive film for black matrices on the substrate; Exposing and developing the photosensitive film using an exposure mask having a light shielding portion, an exposure portion and a partial exposure portion having different exposure intensities to form a photosensitive film pattern; And, And etching the opaque film using the photoresist pattern using an etch mask. Forming a black matrix having recesses on the substrate; And, And forming a spacer at a position corresponding to the recessed portion. The method of claim 6, Forming the black matrix with the recess is: Forming an opaque film and a photosensitive film on the substrate; The photosensitive film is exposed and developed using an exposure mask including a light shielding portion, an exposure portion separated by the light shielding portion, and a partial exposure portion having an exposure intensity between the light shielding portion and the exposure portion in the exposure portion. To form; And, And etching the opaque film by using the photoresist pattern as an etch mask. The method according to claim 6 or 7, And forming a color filter and a transparent electrode prior to forming the spacers. Providing a first substrate having a recess; Providing a second substrate; Forming a spacer in the recess; Bonding the first substrate and the second substrate through the spacers; And, And injecting a liquid crystal between the first substrate and the second substrate. The method of claim 9, Providing a first substrate having the recess is: Forming a black matrix having a recess corresponding to the recess of the first substrate on the transparent substrate; And, And forming a transparent electrode on the black matrix and the transparent substrate.

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