LIQUID CRYSTAL DISPLAY AND MANUFACTURING METHOD THEREOF
This application claims priority to and the benefit of Korean Patent Application No. 10-2015-0083458 filed in the Korean Intellectual Property Office on Jun. 12, 2015, the disclosure of which is incorporated herein by reference in its entirety. The present disclosure relates generally to a liquid crystal display and a manufacturing method thereof. A liquid crystal display panel, which is one of the most common types of flat panel displays currently in use, includes two sheets of substrates with field generating electrodes such as a pixel electrode and a common electrode, and a liquid crystal layer interposed between the two substrates. The liquid crystal display generates electric fields in the liquid crystal layer by applying voltages to the field generating electrodes, determines the alignment of liquid crystal molecules of the liquid crystal layer by the generated electric fields, and controls polarization of incident light, thereby displaying images. A technique of forming a cavity in a pixel and filling the cavity with liquid crystal molecules to implement a liquid crystal display has been developed. Although two sheets of substrates are used in a conventional liquid crystal display, constituent elements are formed on one substrate, thereby reducing weight and thickness of the liquid crystal display. The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure, therefore it may contain information that does not form a prior art that is already known to a person of ordinary skill in the art. The present disclosure provides a display device manufactured by using one substrate. The present display device can be made to be slim and is adequate for a large-size display device. A liquid crystal display, according to an exemplary embodiment, includes: a substrate; a liquid crystal layer positioned on the substrate and formed with a plurality of microcavities including liquid crystal molecules; a roof layer positioned on the liquid crystal layer; a capping layer positioned on the roof layer; and a light source positioned on the capping layer and positioned between the plurality of microcavities. A light guide panel covering the light source and the capping layer may be further included. A diffuser sheet positioned between the light source and the light guide panel and a reflection sheet formed on the light guide panel may be further included. A light blocking member positioned between the capping layer and the light source may be further included. The light guide panel may be patterned at a position corresponding to the light source. A first diffuser sheet positioned between the light source and the light guide panel, and a second diffuser sheet formed on the light guide panel, may be further included. A thin film transistor positioned on the substrate, a pixel electrode connected to the thin film transistor, an upper insulating layer positioned on the roof layer, and a lower insulating layer positioned under the roof layer and facing the pixel electrode based on the microcavities may be further included. The light source may be formed along a liquid crystal inlet formed along a direction that a gate line connected to the thin film transistor extends. A manufacturing method of a liquid crystal display, according to an exemplary embodiment, includes: forming a thin film transistor on a substrate; forming a pixel electrode on the thin film transistor; forming a sacrificial layer on the pixel electrode; forming a roof layer on the sacrificial layer; removing the sacrificial layer to form a plurality of microcavities; injecting a liquid crystal material into the plurality of microcavities; forming a capping layer covering a liquid crystal inlet formed between the plurality of microcavities; and forming a light source positioned on the capping layer and disposed in a liquid crystal inlet formed between the plurality of microcavities. The method may further include forming a light guide panel covering the light source and the capping layer. The method may further include forming a diffuser sheet between the light source and the capping layer before forming the light guide panel. The method may further include forming a reflection sheet on the light guide panel after forming the light guide panel. The method may further include forming a first diffuser sheet on the light source and the capping layer before forming the light guide panel, and forming a second diffuser sheet on the light guide panel after forming the light guide panel. The method may further include forming a light blocking member positioned on the capping layer and facing the liquid crystal inlet formed between the plurality of microcavities after forming the capping layer. The liquid crystal inlet may be formed along a direction in which a gate line connected to the thin film transistor extends. As described above, according to an exemplary embodiment, in the display device manufactured by using one substrate, a light source is positioned between the plurality of microcavities including the liquid crystal molecules such that the thin film and the large size of the display device may be realized. The present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the present disclosure are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present disclosure. In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like reference numerals designate like elements throughout the specification. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. Throughout the specification, components denoted by the same reference numerals are the same components. Referring to A gate insulating layer 140 is formed on the gate line 121 and the storage electrode line 131. A semiconductor layer 151 positioned at a lower portion of a data line 171, and a semiconductor layer 154 positioned at a lower portion of 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 this is omitted in the drawings. Data conductors 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. Here, the data line 171 may have a function of a light blocking member for preventing light leakage, and a width of the data line 171 may be equal to or wider than a width of a partition wall part PWP. The gate electrode 124, the source electrode 173, and the drain electrode 175 form the thin film transistor Q together with the semiconductor layer 154, and a channel of the thin film transistor Q is formed on the portion of the semiconductor layer 154 between the source electrode 173 and the drain electrode 175. A first interlayer insulating layer 180 A color filter 230 is formed on the first interlayer insulating layer 180 A second interlayer insulating layer 180 A contact hole 185 exposing the drain electrode 175 is formed in the color filter 230 and the interlayer insulating layers 180 The fine branch parts 191 The pixel electrode 191 includes an extension part 197 connected to the pixel electrode 191 at a lower end of the vertical stem part 191 The descriptions of the color filter 230, the thin film transistor Q and the pixel electrode 191 stated herein are only an example, and a position of the color filter 230, a structure of the film transistor Q, and a design of the pixel electrode 191 are not limited to the structures described in the present exemplary embodiment, but may be modified 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 may include at least one of generally used materials as a liquid crystal alignment layer such as polyamic acid, polysiloxane, or polyimide. An upper alignment layer 21 is provided 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. The microcavity 305 forms a liquid crystal layer. A liquid crystal material 310 including liquid crystal molecules is injected into the microcavity 305, and the microcavity 305 has an inlet part 307. A plurality of microcavities 305 may be formed along a column direction of the pixel electrode 191, that is, the vertical direction. In the present exemplary embodiment, the alignment material forming the alignment layers 11 and 21 and the liquid crystal material 310 including the liquid crystal molecules may be injected into the microcavity 305 using a capillary force. In the present exemplary embodiment, the lower alignment layer 11 and the upper alignment layer 21 are merely differentiated depending on a position, and may be connected to each other as shown in The microcavity 305 is partitioned in a vertical direction by the liquid crystal injecting parts 307FP positioned at portions overlapped with the gate line 121 to form the plurality of microcavities 305. The plurality of microcavities 305 may be formed along the column direction of the pixel electrode 191, that is, the vertical direction. The liquid crystal injecting parts 307FP are formed in a region where a trench is formed in the manufacturing process of the liquid crystal display according to an exemplary embodiment. In the final structure, as shown in In addition, the microcavity 305 is divided in the horizontal direction by a partition wall part PWP that will be described later, thereby forming the plurality of microcavities 305. The plurality of microcavities 305 may be formed along the row direction of the pixel electrode 191, in other words, the horizontal direction in which the gate line 121 extends. The formed microcavities 305 may respectively correspond to one or more pixel areas, and the pixel areas may correspond to a region displaying an image. A common electrode 270 and a lower insulating layer 350 are positioned 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 an inclination direction in which the liquid crystal molecules 310 positioned at the microcavity 305 between the two electrodes. The common electrode 270 and the pixel electrode 191 form a capacitor 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 the present exemplary embodiment, it is described that the common electrode 270 is formed on the microcavity 305, but in another exemplary embodiment, the common electrode 270 is formed under the microcavity 305, so that liquid crystal display can be driven in a coplanar electrode (CE) mode. A roof layer 360 is disposed on the lower insulating layer 350. The roof layer 360 serves as a support to form the microcavity 305, which is a space between the pixel electrode 191 and the common electrode 270. The roof layer 360 may include silicon oxycarbide (SiOC), a photoresist, or other organic materials. An upper insulating layer 370 is disposed on the roof layer 360. The upper insulating layer 370 may contact the upper surface of the roof layer 360. As shown in The capping layer 390 is disposed on the upper insulating layer 370. The capping layer 390 includes an organic material or an inorganic material. The capping layer 390 may be disposed in the liquid crystal injecting part 307FP as well as on the upper insulating layer 370. In this case, the capping layer 390 may cover the inlet part 307 of the microcavity 305 exposed by the liquid crystal injecting part 307FP. In the present exemplary embodiment, the capping layer 390 extends from the upper insulating layer 370, thereby forming a recessed structure in the liquid crystal injecting parts 307FP. Although the present exemplary embodiment describes the case in which the liquid crystal material is removed from the liquid crystal injecting part 307FP, the liquid material remaining after being injected into the microcavity 305 may remain in the liquid crystal injecting part 307FP. In the present exemplary embodiment, as shown in In the present exemplary embodiment, as shown in In the present exemplary embodiment, as shown in A light guide panel 600 is positioned on the light source 510 and the capping layer 390. The light guide panel 600 guides the light emitted from the light source 510 to be uniformly transmitted to a viewer. In this case, the light guide panel 600 may be a material including an acryl extrusion and is generally manufactured of a poly(methyl methacrylate) (PMMA) material having high light transmittance. In addition, a poly(methacrylstyrene) (MS) material having excellent heat resistance and moisture resistance compared to the PMMA may be used. The light guide panel 600 may be a wedge type plate or a flat type plate, but it is not limited thereto. In the present exemplary embodiment, a diffuser sheet 531 for scattering the light emitted from the light source 510 and irradiated through the light guide panel 600 may be further included. In this case, the diffuser sheet 531 is positioned on a path of the light in a space between the light source 510 and the light guide panel 600. The material of the diffuser sheet 531 may include at least one among a transparent silicon, a polycarbonate, and an acryl resin (PMMA). The diffuser sheet 531 may be made of a soft material, and the exemplary embodiment discloses, for example, a silicon material, and the like, but is not limited thereto, and any material that enables a light cycle may be used. In the present exemplary embodiment, a reflection sheet 520 may be further included to prevent the light emitted from the light source 510 from escaping to the outside of the display device. The reflection sheet 520 reflects the light leaked in the opposite side of the display device so as to prevent the light emitted from the light source 510 from escaping to the outside, thereby changing the light path in a direction of the display device. When the light emitted from the light source 510 is emitted to the upper surface of the light guide panel 600, the reflection sheet 520 reflects the light to return to the light guide panel 600. Referring to When forming a curved display device in which the light source 510 is formed under the substrate 110, the thickness of the display device may be increased. The increase in the thickness may apply an increased tension force to the display device that may cause a damage to the display device may. Further, an edge type display device in which the light source is disposed on an edge of the light guide panel 600 is difficult to apply to a large-sized display. The display device according to an exemplary embodiment does not form the light source 510 under the substrate 110, but forms the light source 510 to be positioned between the microcavities 305 formed on the substrate 110 allowing the thickness of the display device to be reduced. Further, the reduced tension force applied to the display device makes the display device adequate to apply to a large-sized display. Although not shown, a polarizer may be formed between the capping layer 390 and the light guide panel 600. Next, another exemplary embodiment including other constituent elements will be described with reference to Next, the liquid crystal display according to an exemplary embodiment as a modified exemplary embodiment will be described with reference to The diffuser sheets 531 and 532 may include at least one of a transparent silicon, polycarbonate, and an acryl resin (PMMA) material. The diffuser sheet 531 may be made of a soft material, and the exemplary embodiment discloses, for example, a silicon material and the like, but is not limited thereto and any material that enables a light cycle may be used. The liquid crystal display according to the present exemplary embodiment is formed with the diffuser sheets 531 and 532 on and under the light guide panel 600. Accordingly, the light emitted from the light source 510 is not only transmitted under the liquid crystal display through the liquid crystal layer and the color filter 230 along the first diffuser sheet 531 formed under the light guide panel 600, but is also transmitted on the liquid crystal display along the second diffuser sheet 532 formed on the light guide panel 600. In the present exemplary embodiment, a viewer may view the display device in a direction from the lower side of the substrate 110 toward the upper side and a direction from the upper side of the substrate 100 toward the lower side. Referring to Hereafter, an exemplary embodiment manufacturing the above described liquid crystal display will be described with reference to Referring to Next, a pixel electrode 191 is formed on the second interlayer insulating layer 180 Referring to Referring to Referring to Referring to Next, a liquid crystal material is injected to the liquid crystal injecting parts 307FP by using an inkjet process. The liquid crystal material including the liquid crystal molecule 310 may enter into the microcavities 305 through the inlet part 307 by a capillary force, or the like. Referring to Referring to Next, the light source 510 is formed at a position corresponding to the liquid crystal injecting parts 307FP in which the trench 308 is formed between the microcavities 305 adjacent in the horizontal direction. In the present exemplary embodiment, the light source 510 may be formed on the light blocking member 220. When forming a curved display device in which the light source 510 is formed under the substrate 110, the thickness of the display device may be increased. The increase in the thickness may apply an increased tension force to the display device that may cause a damage to the display device. Further, an edge type display device in which the light source is disposed on an edge side of the light guide panel 600 is difficult to apply to the large-sized display. The manufacturing method of the liquid crystal display according to an exemplary embodiment positions the light source 510 between the microcavities 305 formed on the substrate 110 allowing the thickness of the liquid crystal display to be reduced. The reduce tension force applied to the display device makes the display device adequate to apply to the large-sized display. The liquid crystal display described in While the present disclosure has been described in connection with exemplary embodiments, it is to be understood that the present disclosure 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 present disclosure. A liquid crystal display according to an exemplary embodiment includes: a substrate; a liquid crystal layer positioned on the substrate and formed with a plurality of microcavities including liquid crystal molecules; a roof layer positioned on the liquid crystal layer; a capping layer positioned on the roof layer; and a light source positioned on the capping layer and positioned between the plurality of microcavities. 1. A liquid crystal display comprising:
a substrate; a liquid crystal layer positioned on the substrate and formed with a plurality of microcavities including liquid crystal molecules; a roof layer positioned on the liquid crystal layer; a capping layer positioned on the roof layer; and a light source positioned on the capping layer and positioned between the plurality of microcavities. 2. The liquid crystal display of a light guide panel covering the light source and the capping layer. 3. The liquid crystal display of a diffuser sheet positioned between the light source and the light guide panel; and a reflection sheet formed on the light guide panel. 4. The liquid crystal display of a light blocking member positioned between the capping layer and the light source. 5. The liquid crystal display of 6. The liquid crystal display of a first diffuser sheet positioned between the light source and the light guide panel; and a second diffuser sheet formed on the light guide panel. 7. The liquid crystal display of a thin film transistor positioned on the substrate; a pixel electrode connected to the thin film transistor; an upper insulating layer positioned on the roof layer; and a lower insulating layer positioned under the roof layer and facing the pixel electrode based on the microcavities. 8. The liquid crystal display of the light source is formed along a liquid crystal inlet formed along a direction that a gate line connected to the thin film transistor extends. 9. A method for manufacturing a liquid crystal display comprising:
forming a thin film transistor on a substrate; forming a pixel electrode on the thin film transistor; forming a sacrificial layer on the pixel electrode; forming a roof layer on the sacrificial layer; removing the sacrificial layer to form a plurality of microcavities; injecting a liquid crystal material into the plurality of microcavities; forming a capping layer covering a liquid crystal inlet formed between the plurality of microcavities; and forming a light source positioned on the capping layer and disposed in a liquid crystal inlet formed between the plurality of microcavities. 10. The method of 11. The method of forming a diffuser sheet between the light source and the capping layer before forming the light guide panel. 12. The method of forming a reflection sheet on the light guide panel after forming the light guide panel. 13. The method of forming a first diffuser sheet on the light source and the capping layer before forming the light guide panel; and forming a second diffuser sheet on the light guide panel after forming the light guide panel. 14. The method of forming a light blocking member positioned on the capping layer and facing the liquid crystal inlet formed between the plurality of microcavities after forming the capping layer. 15. The method of the liquid crystal inlet is formed along a direction in which a gate line connected to the thin film transistor extends.RELATED APPLICATIONS
BACKGROUND
1. Field
2. Description of the Related Art
SUMMARY
BRIEF DESCRIPTION OF THE DRAWINGS
DETAILED DESCRIPTION
DESCRIPTION OF SYMBOLS
220 light blocking member 300 sacrificial layer 305 microcavity 307 inlet part 307FP liquid crystal injecting parts 308 trench 360 roof layer 390 capping layer 510 light source 600 light guide 531, 532 diffuser sheet 520 reflection sheet




















