Patent Publication Number: US-9429796-B2

Title: Liquid crystal display and method of manufacturing the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to, and the benefit of, Korean Patent Application No. 10-2013-0115351 filed in the Korean Intellectual Property Office on Sep. 27, 2013, the entire contents of which are incorporated herein by reference in their entirety. 
     BACKGROUND 
     1. Field 
     The present disclosure relates to a liquid crystal display and a manufacturing method thereof. 
     2. Description of the Related Technology 
     A liquid crystal display, one of flat panel display devices that are being widely used, includes two display panels, where field generating electrodes such as a pixel electrode and a common electrode are formed with a liquid crystal layer interposed therebetween. 
     The liquid crystal display generates an electric field in the liquid crystal layer by applying a voltage to the field generating electrodes to determine orientations of liquid crystal molecules of the liquid crystal layer and control polarization of incident light, thereby displaying an image. 
     A technology for forming a cavity in a unit of a pixel and filling the cavity with liquid crystals to implement a display has been developed as one of the liquid crystal displays. This technology includes manufacturing a display by forming a sacrificial layer with an organic material, and the like, forming a supporting member on the sacrificial layer, removing the sacrificial layer, and filling an empty space formed through the removal of the sacrificial layer with liquid crystals through a liquid crystal injection hole, instead of forming an upper panel on a lower panel. 
     In a larger-sized liquid crystal display, when filling the liquid crystals in each cavity, the liquid crystals may be not filled in a given region in the cavity. 
     The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. 
     SUMMARY OF CERTAIN INVENTIVE ASPECTS 
     The present disclosure provides a liquid crystal display in which a non-filled region of a liquid crystal is reduced, and a manufacturing method thereof 
     A liquid crystal display according to an embodiment includes: a substrate; a thin film transistor comprising one or more terminals and disposed on the substrate; a pixel electrode connected to one of the terminals of the thin film transistor; and a roof layer disposed to face the pixel electrode, wherein a microcavity is formed between the pixel electrode and the roof layer, the microcavity including a liquid crystal material, wherein a plurality of microcavities are disposed along a first row and a second row adjacent to each other, a trench is formed between the first row and the second row, and at least one bridge connecting the first row and the second row is disposed at the trench. 
     The trench may include a first region having a first cross-section and a second region having a second cross-section, the first cross-section being smaller than the second cross-section, and the first region corresponding to a portion in which the at least one bridge is disposed. 
     The at least one bridge may be disposed at a same layer as the roof layer. 
     The at least one bridge may comprise a same material as the roof layer. 
     A common electrode and a lower insulating layer both disposed between the microcavity and the roof layer may be further included, the lower insulating layer may be disposed on the common electrode, and the common electrode and the lower insulating layer may be extended to be disposed under the bridge. 
     A capping layer disposed on the roof layer may be further included, and the capping layer may fill the trench. 
     A light blocking member disposed on the substrate may be further included, the light blocking member may include a first light blocking member extending in the same direction as a gate line connected to the thin film transistor, and a second light blocking member extending in the same direction as a data line connected to the thin film transistor, wherein the at least one bridge may extend in the same direction as the second light blocking member and may overlap the second light blocking member. 
     The at least one bridge may be disposed at a same layer as the microcavity. 
     An insulating layer disposed between the thin film transistor and the pixel electrode may be further included, the insulating layer may include a convex part, and the convex part may form the at least one bridge. 
     A common electrode and a lower insulating layer disposed between the microcavity and the roof layer may be further included, wherein the lower insulating layer may be disposed on the common electrode. 
     A capping layer disposed on the roof layer may be further included, and the capping layer may fill the trench. 
     A manufacturing method of a liquid crystal display according to an embodiment includes: forming a thin film transistor comprising one or more terminals on a substrate; forming a pixel electrode connected to one of the terminals of the thin film transistor; forming a sacrificial layer on the pixel electrode; forming a roof layer on the sacrificial layer; patterning a lower insulating layer and a common electrode by using the roof layer as a mask; patterning the roof layer to form a trench; removing the sacrificial layer to form a plurality of microcavities having a liquid crystal injection hole; injecting a liquid crystal material into the plurality of microcavities; and forming a capping layer covering the liquid crystal injection hole on the roof layer, wherein the plurality of microcavities is disposed along a first row and a second row adjacent to each other, wherein a trench is formed between the first row and the second row, and wherein at least one bridge connecting the first row and the second row is disposed at the trench. 
     The trench may include a first region having a first cross-section and a second region having a second cross-section, wherein the first cross-section is smaller than the second cross-section, and wherein the first region may correspond to a portion in which the at least one bridge is disposed. 
     In the patterning of the roof layer, the roof layer may be configured to remain in a portion in which the at least one bridge is formed. 
     The at least one bridge may comprise a same material as the roof layer. 
     The method may further include injecting an alignment material into the plurality of microcavities, drying the alignment material, wherein a solid remains after the alignment material is dried and formed under the at least one bridge. 
     The method may further include forming a light blocking member on the substrate, the light blocking member may include a first light blocking member extending in the same direction as a gate line connected to the thin film transistor and a second light blocking member extending in the same direction as a data line connected to the thin film transistor, wherein the at least one bridge may extend in the same direction as the second light blocking member while overlapping the second light blocking member. 
     The method may further include forming an insulating layer between the thin film transistor and the pixel electrode, wherein the insulating layer may include a convex part, and the convex part forms the at least one bridge. 
     The method may further include forming a light blocking member on the substrate, wherein an upper surface of the light blocking member may be protruded corresponding to a portion in which the at least one bridge is disposed. 
     The method may further include forming a common electrode and a lower insulating layer disposed between the plurality of microcavities and the roof layer, wherein the lower insulating layer may be formed to be disposed on the common electrode. 
     According to an embodiment, the bridge is formed in the trench such that the liquid crystal being insufficiently filled in an arbitrary microcavity may be prevented. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a top plan view of a liquid crystal display according to an embodiment. 
         FIG. 2  is a cross-sectional view taken along the line II-II of  FIG. 1 . 
         FIG. 3  is a cross-sectional view taken along the line of  FIG. 1 . 
         FIG. 4  is a top plan view of a portion where a roof layer is disposed in  FIG. 1 . 
         FIG. 5  is a cross-sectional view taken along the line V-V of  FIG. 4 . 
         FIG. 6  is a perspective view of a bridge according to an embodiment in  FIG. 4  and  FIG. 5 . 
         FIG. 7  is a top plan view of a liquid crystal display according to a variation of the embodiment of  FIG. 4 . 
         FIG. 8  is a cross-sectional view of a liquid crystal display according to a variation of the embodiment of  FIG. 5  taken along the line V-V of  FIG. 4 . 
         FIG. 9  is a perspective view of a bridge according to an embodiment in  FIG. 8 . 
         FIG. 10  to  FIG. 22  are cross-sectional views to explain a manufacturing method of a liquid crystal display according to an embodiment. 
         FIG. 23  to  FIG. 28  are cross-sectional views to explain a manufacturing method of a liquid crystal display according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION OF CERTAIN INVENTIVE EMBODIMENTS 
     Hereinafter, certain embodiments of the present invention will be described in detail with reference to the accompanying drawings. As those skilled in the art would realize, the described embodiments may be modified in various ways, without departing from the spirit or scope of the present invention. On the contrary, embodiments introduced herein are provided to make disclosed contents thorough and complete, and sufficiently transfer the spirit of the present invention to those skilled in the art. 
     In the drawings, the thickness of layers, films, panels, regions, etc., may be exaggerated for clarity. It will be understood that when a layer is referred to as being “on” another layer or substrate, it can be directly on the other layer or substrate, or intervening elements may also be present. Like reference numerals generally designate like elements throughout the specification. 
       FIG. 1  is a top plan view of a liquid crystal display according to an embodiment.  FIG. 2  is a cross-sectional view taken along the line II-II of  FIG. 1 .  FIG. 3  is a cross-sectional view taken along the line III-III of  FIG. 1 . 
     Referring to  FIG. 1  to  FIG. 3 , a gate line  121  and a storage electrode line  131  are formed on a substrate  110  made of transparent glass or plastic. The gate line  121  includes a gate electrode  124 . The storage electrode line  131  is mainly extended in a horizontal direction, and transfers a predetermined voltage, such as a common voltage Vcom. The storage electrode line  131  includes a pair of vertical storage electrode portions  135   a  substantially extended to be perpendicular to the gate line  121 , and a horizontal storage electrode portion  135   b  connecting ends of the pair of vertical portions  135   a  to each other. The storage electrode portions  135   a  and  135   b  have a structure surrounding the pixel electrode  191 . 
     A gate insulating layer  140  is formed on the gate line  121  and the storage electrode line  131 . A semiconductor layer  151  disposed under a data line  171 , and a semiconductor layer  154  disposed under a source/drain electrode and at a channel portion of a thin film transistor Q, are formed on the gate insulating layer  140 . 
     A plurality of ohmic contacts may be formed on each of the semiconductor layers  151  and  154 , and between the data line  171  and the source/drain electrode, but they are omitted in the drawings. 
     Data conductors  171 ,  173 , and  175  including a source electrode  173 , a data line  171  connected with the source electrode  173 , and a drain electrode  175  are formed on each of the semiconductor layers  151  and  154  and the gate insulating layer  140 . 
     The gate electrode  124 , the source electrode  173 , and the drain electrode  175  form a thin film transistor Q together with the semiconductor layer  154 , and a channel of the thin film transistor Q is formed on a portion of the semiconductor layer  154  between the source electrode  173  and the drain electrode  175 . 
     A first interlayer insulating layer  180   a  is formed on the data conductors  171 ,  173 , and  175  and an exposed portion of the semiconductor layer  154 . The first interlayer insulating layer  180   a  may include an inorganic insulating material, such as, for example, a silicon nitride (SiNx) and a silicon oxide (SiOx), or an organic insulating material. 
     A color filter  230  and a light blocking member  220  are formed on the first interlayer insulating layer  180   a.    
     The light blocking member  220  has a lattice structure having an opening corresponding to a region for displaying an image, and is formed of a material that prevents light from being transmitted. The color filter  230  is formed at the opening of the light blocking member  220 . The light blocking member  220  includes a first light blocking member  220   a  formed in a direction parallel to the gate line  121  and a second light blocking member  220   b  formed in a direction parallel to the data line  171 . 
     The color filter  230  may display one of primary colors, such as, for example, three primary colors including red, green, and blue. However, the colors are not limited to the three primary colors including red, green, and blue, and the color filter  230  may also display one among a cyan-based color, a magenta-based color, a yellow-based color, and a white-based color. The color filter  230  may be formed of a material displaying different colors for each adjacent pixel. 
     A second interlayer insulating layer  180   b  covering the color filter  230  and the light blocking member  220  is formed on the color filter  230  and the light blocking member  220 . The second interlayer insulating layer  180   b  may include an inorganic insulating material, such as, for example, a silicon nitride (SiNx) and a silicon oxide (SiOx), or an organic insulating material. Contrary to the illustration in the cross-sectional view of  FIG. 2 , in a case where a step is generated due to a difference in thickness between the color filter  230  and the light blocking member  220 , the second interlayer insulating layer  180   b  includes an organic insulating material, so that it is possible to decrease or eliminate the step. 
     The color filter  230 , the light blocking member  220 , and the interlayer insulating layers  180   a  and  180   b  have a contact hole  185  exposing the drain electrode  175 . 
     A pixel electrode  191  is disposed on the second interlayer insulating layer  180   b . The pixel electrode  191  may be formed of a transparent conductive material, such as ITO or IZO. 
     An entire shape of the pixel electrode  191  is a quadrangle, and includes a cross-shaped stem portion including a transverse stem portion  191   a  and a longitudinal stem portion  191   b  crossing the transverse stem portion  191   a . Further, the pixel electrode  191  has four sub-regions because of the transverse stem  191   a  and the longitudinal stem  191   b , and each of the sub-regions includes a plurality of fine branches  191   c . In one embodiment, the pixel electrode  191  further includes an outer stem enclosing the outer portion. 
     The fine branch portions  191   c  of the pixel electrode  191  form an angle of about 40 degrees to about 45 degrees with the gate line  121  or the transverse stem  191   a . Further, the minute branches of two adjacent subregions may be perpendicular to each other. In addition, a width of the fine branch  191   c  may become gradually larger or intervals between the fine branches  191   c  may be different from each other. 
     The pixel electrode  191  includes an extended portion  197  connected at a lower end of the longitudinal stem  191   b  and having a wider area than that of the longitudinal stem  191   b , and is physically and electrically connected with the drain electrode  175  through the contact hole  185  at the extended portion  197 , and receives a data voltage from the drain electrode  175 . 
     The description of the aforementioned thin film transistor Q and pixel electrode  191  is one example, and a structure of the thin film transistor and a design of the pixel electrode may be modified in order to improve side visibility. 
     A lower alignment layer  11  is formed on the pixel electrode  191 , and the lower alignment layer  11  may be a vertical alignment layer. The lower alignment layer  11 , which is a liquid crystal alignment layer, may be formed of any one among generally used materials such as, for example, polyamic acid, polysiloxane, or a polyimide. 
     An upper alignment layer  21  is disposed at a portion facing the lower alignment layer  11 , and a microcavity  305  is formed between the lower alignment layer  11  and the upper alignment layer  21 . A liquid crystal material including liquid crystal molecules  310  is injected into the microcavity  305  through a liquid crystal injection hole  307 . The microcavity  305  may be formed along a column direction of the pixel electrode  191 , or, a vertical direction. In one embodiment, an alignment material forming the alignment layers  11  and  21  and the liquid crystal material including the liquid crystal molecules  310  may be injected into the microcavity  305  by using capillary force. It may be described that the microcavity  305  is a space of the pixel electrode  191  and a common electrode  270 , and the alignment layers  11  and  21  are formed in the microcavity  305 . 
     The microcavity  305  is divided in a vertical direction by a plurality of trenches  307 FP disposed at a portion overlapping the gate line  121 , and a plurality of microcavities  305  may be formed along the direction in which the gate line  121  is extended. Each of the plurality of formed microcavities  305  may correspond to a pixel area, and the pixel areas may correspond to a region displaying an image. 
     The common electrode  270  and a lower insulating layer  350  are disposed on the upper alignment layer  21 . The common electrode  270  receives the common voltage, and generates an electric field together with the pixel electrode  191  to which the data voltage is applied to determine a direction in which the liquid crystal molecules  310  disposed at the microcavity  305  between the two electrodes are inclined. The common electrode  270  forms a capacitor with the pixel electrode  191  to maintain the received voltage even after the thin film transistor is turned off. The lower insulating layer  350  may be formed of a silicon nitride (SiNx) or a silicon oxide (SiOx). 
     In one embodiment, it is described that the common electrode  270  is formed on the microcavity  305 , but in another embodiment, the common electrode  270  is formed under the microcavity  305 , so that liquid crystal driving according to a coplanar electrode (CE) mode is possible. 
     A roof layer  360  is disposed on the lower insulating layer  350 . The roof layer  360  serves to make a support so that the microcavity  305 , which is a space between the pixel electrode  191  and the common electrode  270 , is formed. The roof layer  360  may include a photoresist or other organic materials. 
     The roof layer  360  according to one embodiment will be described in detail with reference to  FIG. 4  to  FIG. 6 . 
       FIG. 4  is a top plan view of a portion where a roof layer is disposed in  FIG. 1 .  FIG. 5  is a cross-sectional view taken along the line V-V of  FIG. 4 .  FIG. 6  is a perspective view of a bridge according to an embodiment in  FIG. 4  and  FIG. 5 . 
     Referring to  FIG. 4  and  FIG. 5 , in one embodiment, a plurality of microcavities  305  are disposed according to a first row A and a second row B, and the trench  307 FP is formed between the first row A and the second row B. In one embodiment, at least one bridge  361  connecting the first row A and the second row B is disposed at the trench  307 FP. The roof layer  360  is elongated according to the first row A and the second row B, and is formed to connect the first row A and the second row B thereby forming the bridge  361 . At this time, the bridge  361  may be formed with the same material as the roof layer  360  and may be disposed at a same layer as the roof layer  360 . 
     Referring to  FIG. 6 , a first region X of the trench  307 FP corresponding to the portion where the bridge  361  is disposed has a first cross-section, and a second region Y of the trench  307 FP except for the first region X has a second cross-section. The first cross-section is smaller than the second cross-section. 
     As shown in  FIG. 5 , the common electrode  270  and the lower insulating layer  350  disposed between the microcavity  305  and the roof layer  360  are extended, and may be disposed under the roof layer  360  forming the bridge  361 . 
     In one embodiment, the bridge  361  may extend in the same direction as the second light blocking member  220   b  while overlapping the second light blocking member  220   b . However, this structure is not limited, and the bridge  361  may be formed with an oblique shape. 
     Referring to  FIG. 2 ,  FIG. 3 , and  FIG. 5 , an upper insulating layer  370  is disposed on the roof layer  360 . The upper insulating layer  370  may contact an upper surface of the roof layer  360 . The upper insulating layer  370  may be formed of, for example, a silicon nitride (SiNx) or a silicon oxide (SiOx). 
     A capping layer  390  is disposed on the upper insulating layer  370 . The capping layer  390  covers a liquid crystal injection hole  307  of the microcavity  305  exposed by the trench  307 FP while filling the trench  307 FP. The capping layer  390  may be made of, for example, a thermosetting resin, silicon oxycarbide (SiOC), or graphene. As shown in  FIG. 5 , the capping layer  390  may fill the lower end of the bridge  361 . 
     An overcoat layer (not illustrated) formed of an inorganic or organic material may be disposed on the capping layer  390 . The overcoat layer serves to protect the liquid crystal molecules  310  injected into the microcavity  305  from an external impact, and to planarize the layer. 
     In one embodiment, a partition wall forming portion (PWP) is formed between the microcavity  305  adjacent in the horizontal direction, as shown in  FIG. 3 . The partition wall forming portion (PWP) may be formed according to the extending direction of the data line  171 , and may be covered by the roof layer  360 . The partition wall forming portion PWP is filled with the lower insulating layer  350 , the common electrode  270 , the upper insulating layer  370 , and the roof layer  360 , and the structure forms a partition wall so that the microcavity  305  may be divided or defined. 
     A polarizer (not shown) is disposed on the lower and upper insulating layers  350  and  370  of the substrate  110 . The polarizer may include, for example, a polarizing element generating polarized light and a tri-acetyl-cellulose (TAC) layer for securing durability, and in various embodiments, directions of transmissive axes of an upper polarizer and a lower polarizer may be perpendicular or parallel to each other. 
       FIG. 7  is a top plan view of a liquid crystal display according to a variation of the embodiment of  FIG. 4 . 
     The embodiment of  FIG. 7  is mostly the same as the embodiment of  FIG. 4 , except for the formation position of the bridge  361 . Referring to  FIG. 7 , the bridge  361  is disposed between the microcavity  305  of the first row A and the second row B. Except for this difference, the complete description of the embodiment of  FIG. 4  may be applied to embodiment of  FIG. 7 . 
       FIG. 8  is a cross-sectional view of a liquid crystal display according to a variation of the embodiment of  FIG. 5  taken along the line V-V of  FIG. 4 .  FIG. 9  is a perspective view of a bridge according to an embodiment in  FIG. 8 . 
     The embodiment of  FIG. 8  and  FIG. 9  is mostly the same as the embodiment of  FIG. 5  and  FIG. 6 , except for the formation position of the bridge. Referring to  FIG. 8  and  FIG. 9 , the bridge  361  is disposed at substantially a same layer as the microcavity  305 . In one embodiment, the bridge  361  is formed by a convex part formed by a step of the second interlayer insulating layer  180   b . The step of the second interlayer insulating layer  180   b  may be formed by a step of the underlying first light blocking member  220   a.    
     Referring to  FIG. 9 , the first region X of the trench  307 FP corresponding to the portion where the bridge  361  is disposed has a first cross-section, and the second region Y of the trench  307 FP except for the first region X has a second cross-section. The first cross-section is smaller than the second cross-section. 
     In one embodiment, the upper end of the bridge  361  may be filled by the capping layer  390 . Except for this difference, the complete description of the embodiment of  FIG. 5  and  FIG. 6  may be applied to the present embodiment. 
     Next, an embodiment of manufacturing the liquid crystal display will be described with reference to  FIG. 10  to  FIG. 22 . 
       FIG. 10  to  FIG. 22  are cross-sectional views to explain a manufacturing method of a liquid crystal display according to an embodiment.  FIGS. 10, 13, 15, 17, 18, and 21  sequentially show the cross-sectional view taken along the line II-II of  FIG. 1 .  FIGS. 11 and 19  sequentially show the cross-sectional view taken along the line of  FIG. 1 .  FIGS. 12, 14, 16, 20, and 22  sequentially show the cross-sectional view taken along the line V-V of  FIG. 4 . 
     Referring to  FIG. 1  and  FIG. 10  to  FIG. 12 , to form a switching element on a substrate  110 , a gate line  121  extending in the horizontal direction, a gate insulating layer  140  on the gate line  121 , semiconductor layers  151  and  154  on the gate insulating layer  140 , and a source electrode  173  and a drain electrode  175  are formed. A data line  171  connected to the source electrode  173  may be formed to be extended in the longitudinal direction while intersecting the gate line  121 . 
     A first interlayer insulating layer  180   a  is formed on the data conductor including the source electrode  173 , the drain electrode  175 , and the data line  171 , and on the exposed semiconductor layer  154 . 
     A color filter  230  is formed on the first interlayer insulating layer  180   a  at a position corresponding to the pixel area, and a light blocking member  220  is formed between the color filters  230 . 
     A second interlayer insulating layer  180   b  is formed on the color filter  230  and the light blocking member  220  while covering the color filter  230  and the light blocking member  220 , and the second interlayer insulating layer  180   b  has a contact hole  185  to electrically and physically connect the pixel electrode  191  and the drain electrode  175 . 
     Next, a pixel electrode  191  is formed on the second interlayer insulating layer  180   b , and a sacrificial layer  300  is formed on the pixel electrode  191 . As shown in  FIG. 11 , an open part (OPN) is formed in the sacrificial layer  300  according to the direction parallel to the data line  171 . The common electrode  270 , the lower insulating layer  350 , the roof layer  360 , and the upper insulating layer  370  are filled in the open part (OPN), thereby forming the partition forming portion (PWP). 
     Referring to  FIG. 13  and  FIG. 14 , the common electrode  270 , the lower insulating layer  350 , and the roof layer  360  are sequentially formed on the sacrificial layer  300 . The roof layer  360  is located between pixel areas neighboring in a vertical direction by exposure and development processes, and may be removed from an area corresponding to the light blocking member  220 . The roof layer  360  exposes the lower insulating layer  350  to the outside in the area corresponding to the light blocking member  220 . In one embodiment, the portion of the roof layer  360  corresponding to the portion where the bridge  361  is formed is not removed but is maintained. When removing the roof layer  360  in the region corresponding to the first light blocking member  220   a  by the exposure and developing process, a method using a blocking mask covering the portion where the bridge  361  is formed may be applied. 
     Referring to  FIG. 15  and  FIG. 16 , the upper insulating layer  370  covering the roof layer  360  and the exposed lower insulating layer  350  is formed. 
     Referring to  FIG. 17 , the upper insulating layer  370 , the lower insulating layer  350 , and the common electrode  270  are dry etched by using an etching mask. In  FIG. 17 , each side of the upper insulating layer  370 , the roof layer  360 , the lower insulating layer  350 , and the common electrode  270  are shown to be disposed on the same line, however the upper insulating layer  370  may cover the side of the roof layer  360  by controlling a boundary of the etching mask. 
     The trench  307 FP is formed by partially removing the upper insulating layer  370 , the lower insulating layer  350 , and the common electrode  270 . As shown in  FIG. 17 , the sacrificial layer  300  is exposed. 
     Referring to  FIG. 18  to  FIG. 20 , the sacrificial layer  300  exposed through the trench  307 FP is removed by an O 2  ashing process or a wet etching method. The microcavity  305  having the liquid crystal injection hole  307  is formed. The microcavity  305  is in a state of an empty space according to the removal of the sacrificial layer  300 . As shown in  FIG. 20 , the bridge  361  is formed and the sacrificial layer  300  is removed under the bridge  361  such that the trench  307 FP′ having a relatively smaller cross-section is formed. 
     Referring to  FIG. 21  and  FIG. 22 , an alignment material is injected through the liquid crystal injection hole  307  to form the alignment layers  11  and  21  on the pixel electrode  191  and the common electrode  270 . A bake process is performed after the alignment material including solids and a solvent is injected through the liquid crystal injection hole  307 . The solids are accumulated to the portion of the trench  307 FP′ having the relatively smaller cross-section and disposed under the bridge  361 , thereby having a function of supporting the bridge  361 . 
     Next, a liquid crystal material including the liquid crystal molecules  310  is injected into the microcavity  305  through the liquid crystal injection hole  307  by using an inkjet method and the like. At this time, by an influence of a surface tension and a capillary force according to the bridge  361  according to an embodiment, in one trench  307 FP, the liquid crystals may be prevented from being concentrated or disconnected in the space between the microcavity  305  disposed at the upper end and the microcavity  305  disposed at the lower end. 
     Next, the capping layer  390  covering the liquid crystal injection hole  307  and filling the trench  307 FP is formed on the upper insulating layer  370 , thereby forming the liquid crystal display shown in  FIG. 1  to  FIG. 5 . 
     The capping layer  390  may be formed by pushing a capping material from one side edge to the other side edge on the substrate  110  by using a bar coater, and simultaneously hardening it by using ultraviolet rays. At this time, the capping material goes into the trench  307 FP′ having the relatively large cross-section under the bridge  361  such that the liquid crystal material remaining on the roof layer  360  by overflow of the liquid crystal material and then consequent light leakage being generated may be prevented. 
       FIG. 23  to  FIG. 28  are cross-sectional views to illustrate a manufacturing method of a liquid crystal display according to an embodiment. 
     The embodiment described with reference to  FIG. 23  to  FIG. 28  is almost the same as the embodiment described with reference to  FIG. 10  to  FIG. 22 . However, the formation position of the bridge  361  is different, and this difference will be mainly described. 
     Referring to  FIG. 23 , the first light blocking member  220   a  is formed to partially have a step and the second interlayer insulating layer  180   b  is formed thereon. The second interlayer insulating layer  180   b  has a convex part caused by the step of the first light blocking member  220   a . The sacrificial layer  300  is formed on the pixel electrode  191   b  and the convex part of the second interlayer insulating layer  180   b.    
     Referring to  FIG. 24 , the common electrode  270 , the lower insulating layer  350 , and the roof layer  360  are sequentially formed on the sacrificial layer  300 . The roof layer  360  may be removed in the region corresponding to the first light blocking member  220   a  disposed between the pixel areas adjacent in the vertical direction by an exposure and development process. The roof layer  360  exposes the lower insulating layer  350  in the region corresponding to the first light blocking member  220   a.    
     Referring to  FIG. 25 , the upper insulating layer  370  covering the roof layer  360  and the exposed lower insulating layer  350  is formed. 
     Referring to  FIG. 26 , the upper insulating layer  370 , the lower insulating layer  350 , and the common electrode  270  are dry etched by using an etching mask. The trench  307 FP is formed by partially removing the upper insulating layer  370 , the lower insulating layer  350 , and the common electrode  270 . At this time, as shown in  FIG. 26 , the sacrificial layer  300  exposed. 
     Referring to  FIG. 27 , the sacrificial layer  300  exposed through the trench  307 FP is removed by an O 2  ashing process or a wet etching method. The sacrificial layer  300  is removed and the microcavity  305  of the empty state is formed. As shown in  FIG. 27 , the bridge  361  is formed and the convex part of the second interlayer insulating layer  180   b  resultantly remains as the bridge  361 . However, the method of forming the second interlayer insulating layer  180   b  as the bridge  361  is not limited, and a separate structure may be formed on the second interlayer insulating layer  180   b  to form the bridge  361 . 
     Referring to  FIG. 28 , an alignment material is injected through the liquid crystal injection hole  307  to form the alignment layers  11  and  21  on the pixel electrode  191  and the common electrode  270 . The bake process is performed after the alignment material including solids and a solvent is injected through the liquid crystal injection hole  307 . 
     Next, the liquid crystal material including the liquid crystal molecules  310  is injected into the microcavity  305  through the liquid crystal injection hole  307  by using an inkjet method and the like. By an influence of a surface tension and a capillary force according to the bridge  361  according to one embodiment, in one trench  307 FP, the liquid crystal may be prevented from being concentrated or disconnected in the space between the microcavity  305  disposed at the upper end and the microcavity  305  disposed at the lower end. Also, the bridge  361  according to one embodiment forms a threshold such that the liquid crystal material in the trench  370 FP is not over a predetermined amount thereby controlling speed of liquid crystal injection. 
     Next, the capping layer  390  covering the liquid crystal injection hole  307  and filling the trench  307 FP is formed on the upper insulating layer  370 , thereby forming the liquid crystal display shown in  FIG. 8 . 
     Except for the described difference, the complete description of the embodiment of  FIG. 10  to  FIG. 22  may be applied to the present embodiment. 
     While this invention has been described in connection with certain embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.