Patent Publication Number: US-2019171053-A1

Title: Liquid crystal display panel and manufacturing method thereof

Description:
RELATED APPLICATIONS 
     The present application is a continuation of International Application Number PCT/CN2018/071301, filed Jan. 4, 2018, and claims the priority of China Application No. 201711250079.3, filed Dec. 1, 2017. 
    
    
     FIELD OF THE DISCLOSURE 
     The disclosure relates to the field of display technology, and in particular to a liquid crystal display panel and a manufacturing method thereof. 
     BACKGROUND 
     Liquid crystal display (LCD) has many advantages such as thin body, energy saving, no radiation and has been widely used. The working principle of a liquid crystal display mainly lies in that liquid crystal molecules are arranged in two parallel substrates, and there are many vertical and horizontal small electric wires in the middle of the two substrates. The liquid crystal molecules can be controlled by changing the electric field intensity of the liquid crystal molecules light intensity to display the image. 
     The photo spacers are formed between the two substrates. In the curved/flexible display panel, when the two substrates are curved or bent into a curved structure, the photo spacer is easily separated from the substrate to which it is connected, so that light leakage and color shift phenomenon easily occur. 
     SUMMARY 
     To solve the above problems, the disclosure provides a liquid crystal display panel and a manufacturing method thereof. 
     A liquid crystal display panel includes a first substrate and a second substrate disposed opposite to the first substrate. The liquid crystal display panel further includes a polymer wall formed on the first substrate, and the polymer wall is located between the first substrate and the second substrate. The liquid crystal display panel is a curved display panel or a flexible display panel. 
     Further, the polymer wall is made of a black photo spacer, and the polymer wall includes a photo spacer region and a black matrix region disposed in connection with the photo spacer region. 
     Further, the photo spacer region includes a main photo spacer region and an auxiliary photo spacer region, and the main photo spacer region is connected between the second substrate and the first substrate. The auxiliary photo spacer region is disposed on the first substrate, and a gap is formed between the auxiliary photo spacer region and the second substrate. 
     Further, the first substrate includes a bottom surface disposed on a side of the first substrate away from the second substrate, the bottom surface extends along a first direction and a second direction to form a plane, and the first direction and the second direction is vertical, the polymer wall extends along the first direction, and the liquid crystal display panel may be bent along the second direction. 
     Further, the liquid crystal display panel further includes a plurality of data line regions arranged at intervals, each of the data line regions extends along a first direction, a number of the polymer wall is plural, and each of the polymer walls is disposed on one of the data line regions. 
     Further, the liquid crystal display panel further includes a plurality of gate line regions arranged at intervals, each of the gate line regions extends along a second direction, and a number of the polymer wall is plural, each of the polymer walls is disposed on one of the gate line regions. 
     Further, the first substrate is an array substrate, and the second substrate is a color filter substrate. 
     Further, the first substrate is a color filter substrate, and the second substrate is an array substrate. 
     A manufacturing method of a liquid crystal display panel is provided, the liquid crystal display panel is a curved display panel or a flexible display panel, and the manufacturing method includes the following steps: 
     forming a polymer wall on a first substrate; and 
     assembling the first substrate and a second substrate into a cell. 
     Further, the polymer wall is made of a black photo spacer and integrally formed on the first substrate by a selective ultraviolet exposure process, and the polymer wall includes a photo spacer region and a black matrix region disposed in connection with the photo spacer region. 
     Further, the step of assembling the first substrate and a second substrate into a cell precedes the step of forming a black photo spacer on a first substrate, and an interlayer material of a black photo spacer photosensitive monomer is disposed between the first substrate and the second substrate. 
     In the liquid crystal display panel and the manufacturing method thereof according to the disclosure, a polymer wall is formed between the first substrate and the second substrate. Since the connection area between the polymer wall and the first substrate is relatively large; the connection strength between the polymer wall and the first substrate is strengthened to prevent the polymer wall from being easily detached from the first substrate, thereby avoiding the light leakage and color shift phenomenon. In addition, the black photo spacer technology is used to form the polymer walls of different heights on the first substrate through a single process, the polymer wall has the dual functions of a photo spacer and a black matrix; thereby reducing the cost and enhancing the light blocking effect and contrast. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       To describe the technical solutions in the embodiments of the disclosure more clearly, the following briefly introduces the accompanying drawings required for describing the embodiments. Apparently, the accompanying drawings in the following description show merely some embodiments of the disclosure, those of ordinary skill in the art may also derive other drawings from these accompanying drawings without creative efforts. 
         FIG. 1  is a schematic view of a liquid crystal display panel; 
         FIG. 2  is a partial cross-sectional view of a liquid crystal display panel according to an embodiment of the disclosure; 
         FIG. 3  is a schematic view of a portion of a liquid crystal display panel; 
         FIG. 4  is a partial cross-sectional view of a liquid crystal display panel; 
         FIG. 5  is a schematic view of another portion of a liquid crystal display panel; 
         FIG. 6  is a flowchart of a manufacturing method of a liquid crystal panel provided by the disclosure; and 
         FIG. 7  is a flowchart of another manufacturing method of a liquid crystal display panel provided by the disclosure. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The following sections offer a clear, complete description of this disclosure in combination with the embodiments and accompanying drawings. Obviously, the embodiments described herein are only a part of, but not all of the embodiments of this disclosure. In view of the embodiments described herein, any other embodiment obtained by those of ordinary skill in the art skilled in this art without offering creative effort is included in a scope claimed by this disclosure. 
     Referring to  FIG. 1 , the disclosure provides a liquid crystal display panel  100 . The liquid crystal display panel  100  extends into a flat plate shape along a first direction X and a second direction Y perpendicular to the first direction X. The liquid crystal display panel  100  is a flexible display panel. The liquid crystal display panel  100  may be bent along the second direction Y. In an embodiment, the liquid crystal display panel  100  is a curved display panel, and the curved display panel is curved along a second direction Y to form a curved surface. 
     Referring to  FIG. 2 , the liquid crystal display panel  100  includes a first substrate  20  and a second substrate  40  disposed opposite to the first substrate  20 , and a polymer wall  30  formed on the first substrate  20 . The polymer wall  30  is interlayered between the second substrate  40  and the first substrate  20 . Certainly, a structure such as a liquid crystal layer (not shown) is further disposed between the first substrate  20  and the second substrate  40 . To save space, details are not described herein again. 
     The polymer wall  30  is a black photo spacer (BPS). The polymer wall  30  plays a dual role of a black matrix (BM) and a photo spacer (PS), The BPS is made of a black photosensitive resin or other organic materials. In the present embodiment, the polymer wall  30  is formed on the first substrate  20  by a selective exposure and development using the black photosensitive resin or other organic materials. In other words, the polymer wall  30  including the photo spacer region  31  and the black matrix region  33  is formed on the first substrate  20  through a process. 
     The polymer wall  30  extends along the first direction X. Further, a length of the polymer wall  30  extending along the first direction X is much larger than a length of the polymer wall  30  extending along the second direction Y. The liquid crystal display panel  100  can be bent along the second direction Y and the polymer wall  30  extends along the first direction X. Since the polymer wall  30  has a larger connection area with the first substrate  20 , the polymer wall  30  can be prevented from being detached from the first substrate  20  or sliding on the first substrate  20  during the bending. 
     Further, in the present embodiment, the first substrate  20  is an array substrate and the second substrate  40  is a color filter substrate. 
     The first substrate  20  includes a base substrate  21 , an electrode layer  22 , a color resist layer  23 , and a protective layer  24 . The base substrate  21  includes a bottom surface  211 , a bottom surface  211  is disposed on a side of the substrate  21  away from the second substrate  40 . The bottom surface  211  extends into a plane along the first direction X and the second direction Y. The electrode layer  22  is disposed on a side of the base substrate  21  away from the bottom surface  211 . The color resist layer  23  is disposed on the electrode layer  22 . The color resist layer  23  includes a plurality of color resists  231 . The protective layer  24  covers the color resist layer  23  and the electrode layer  22 . In the present embodiment, the material of the protective layer  24  is made of organic material. The material of the protective layer  24  may also be made of an inorganic material such as silicon oxide (SiO) or silicon nitride (SiN). In the present embodiment, the substrate  21  is made of a flexible material, which can be a plastic or polymer material such as PI/PET/TAC/PEN/PDMS. 
     The polymer wall  30  is disposed on the protective layer  24  and extends along a first direction X. The vertical distance of the photo spacer region  31  from the top surface of the first substrate  20  to the bottom surface  211  is a first vertical distance, and the vertical distance of the black matrix region  33  away from the top surface of the first substrate  20  to the bottom surface  211  is a second vertical distance, and the first vertical distance is smaller than the second vertical distance. A gap is formed between the top surface of the black matrix region  33  and the second substrate  40  (not shown). The photo spacer region  31  includes a main photo spacer region  311  and an auxiliary photo spacer region  313 . 
     The main photo spacer region  311  is connected between the second substrate  40  and the protective layer  24  to support the cell thickness, Since both ends of the main photo spacer region  311  are firmly connected between the second substrate  40  and the protective layer  24 , no sliding occurs at both ends of the main photo spacer region  311  when the liquid crystal display panel  100  is bent, which can effectively limit the shift caused by the motion of the liquid crystal. Further, since the main photo spacer region  311  is not easily offset, the light leakage and the color shift phenomenon induced by pressing are effectively avoided. 
     The auxiliary photo spacer region  313  is disposed on the protective layer  24 , and a gap (not shown) is formed between the top surface of the auxiliary photo spacer region  313  away from the protective layer  24  and the second substrate  40  to prevent the liquid crystal display panel  100  from being damaged by extrusion. The auxiliary photo spacer region  313  also prevents light leakage. 
     The polymer wall  30  has a multistage structure, and in the vertical distance from the top surface of the polymer wall  30  away from the first substrate  20  to the bottom surface  211  from high to low in order are the main photo spacer region  311 , the auxiliary photo spacer region  313 , and the black matrix region  33 . 
     Referring to  FIG. 3 , the number of the polymer wall  30  is plural, and the length of each of the polymer walls  30  along the first direction X is different. It can be understood that the extending lengths of the plurality of polymer walls  30  along the first direction X can be set to be the same, which is set according to actual needs. 
     The liquid crystal display  100  further includes a plurality of data line (DL) regions  41  arranged at intervals. Each of the DL regions  41  extends along the first direction X. The number of the polymer wall  30  is plural, and each of the polymer walls  30  are disposed in one of the DL regions  41 . 
     The plurality of polymer walls  30  includes a first polymer wall  301 , a second polymer wall  302 , a third polymer wall  303 , and a fourth polymer wall  304 . The first polymer wall  301 , the second polymer wall  302 , the third polymer wall  303 , and the fourth polymer wall  304  are arranged in ascending order along the first direction X. In some embodiments, the number of the first polymer wall  301 , the second polymer wall  302 , the third polymer wall  303 , and the fourth polymer wall  304  are plural, and the plurality of polymer walls  30  is periodically arranged along the second direction in accordance with the first polymer wall  301 , a second polymer wall  302 , a third polymer wall  303  and fourth polymer wall  304  in the order. It is understood that the plurality of polymer walls  30  may include a plurality of polymer walls of different lengths, and the plurality of polymer walls  30  may be arranged differently. 
     Further, the liquid crystal display panel  100  further includes a plurality of subpixel regions  105  and a plurality of gate line (GL) regions  43 . Each of the DL regions  41  extends along the first direction X. The plurality of DL regions  41  are spaced along the second direction Y. The plurality of GL regions  43  extends along the second direction Y, and the plurality of GL regions  43  are spaced along the first direction X. The DL regions  41  and the GL regions  43  are disposed to cross and surround a subpixel region  105 . The liquid crystal display panel  100  is disposed with a color resist  231  in the sub-pixel region  105 . The liquid crystal display panel  100  is disposed with data lines (not shown) in the DL region  41 . The liquid crystal display panel  100  is disposed with gate lines (not shown) in the GL region  43 . The polymer wall  30  is formed in the DL region  41  and has a dual function of a photo spacer and a black matrix. The black matrix layer does not need to be formed by a multiple process, so that the thickness from the top surface of the polymer wall  30  to the bottom surface  211  in the DL region  41  is reduced, conducive to the flow and diffusion of polyimide (PI) solution and liquid crystal molecules. 
     In an embodiment, the polymer wall  30  extends along the second direction Y, that is, the polymer wall  30  is disposed in the GL region  43 . That is, the liquid crystal display panel  100  includes a plurality of GL regions  43  disposed at intervals, and each of the GL region  43  extends along the second direction Y, and the number of the polymer walls  30  is plural, and each of the polymer walls  30  is disposed in one of the GL regions  43 . 
     Further, referring to  FIG. 2  again, the first substrate  20  forms a protrusion on a position corresponding to the color resist layer  23 , thereby forming a step structure of the first substrate  20 . The color resist layer  23  and the protective layer  24  are stacked in the third direction Z. The color resist region  101  and the non-color resist region  103  of the liquid crystal display panel  100  are formed by the color resist layer  23 . The color resist region  101  corresponds to a region where the color filter layer  23  is disposed on the first substrate  20  and the non-color resist region  103  corresponds to a region where the color filter layer  23  is not disposed on the first substrate  20 . A protrusion will be formed at a position of the color resist region  101  corresponding to the protective layer  24 . 
     The photo spacer region  31  is correspondingly disposed on the color resist region  101 , a plane of the step difference layer having the highest step height corresponds to the main photo spacer region  311 , and the other positions of the step difference layer corresponds to the black matrix region  33 . 
     A region where two adjacent color resists  231  are connected to each other and a step difference is not formed between the two adjacent color resists  231  is called a first color filter region, the vertical distance of the two color resists  231  away from the top surface  21  to the bottom surface  211  is the same. The main photo spacer region  311  formed in the first color resist region not only has the function of supporting the cell thickness but also prevents the motion of the liquid crystal. In the manufacture of the liquid crystal display panel  100 , exposure and development are performed through a photomask having a different light transmittance, thereby forming a multistage polymer wall  30  on the first substrate  20 . The polymer wall  30  includes a main photo spacer region  311 , an auxiliary spacer region  313 , and a black matrix region  33 . 
     Of course, the polymer wall  30  can be fabricated by utilizing the multistage structure of the first substrate  20 . For example, referring to  FIG. 4 , a color resist  231  is partially stacked on the adjacent color resist  231  between two adjacent color resistors  231  to form a step difference layer structure, and this area is referred to as a second color resist region. The main photo spacer region  311  having a certain height is formed on the second color resist region. 
     It may be understood that the first substrate  20  may be a color filter substrate, and the second substrate  40  may be an array substrate. 
     It can be understood that the first direction X is not limited to perpendicular to the second direction Y, the third direction Z is not limited to perpendicular to the first direction X, and the third direction Z is not limited to perpendicular to the second direction Y. 
     Referring to  FIG. 5 , the liquid crystal display panel  100  further includes a plurality of spacer structures  50 , the spacer structures  50  are formed on the first substrate  20 , the spacer structures  50  extends along the third direction Z into a pillar shape; the height of the spacer structures  50  extending along the third direction Z may be set to be different to function as the main photo spacer region, the auxiliary photo spacer region, and the black matrix region, respectively. 
     Referring to  FIG. 6 , the disclosure further provides a manufacturing method of a liquid crystal display panel  100 , including the following steps: 
     S 101 : forming a polymer wall  30  on the first substrate  20 . 
     The polymer wall  30  is made of a black photo spacer and integrally formed on the first substrate  20  by a selective ultraviolet exposure process. The polymer wall  30  includes a photo spacer region  31  and a black matrix region  33  disposed in connection with the photo spacer region  31 . 
     Further, the photo spacer region  31  includes a main photo spacer region  311  and an auxiliary photo spacer region  313 . 
     S 102 : assembling the second substrate  40  and the first substrate  20  into a cell to form a liquid crystal display panel  100 , and the polymer wall  30  is disposed between the first substrate  20  and the second substrate  40 . 
     In the present embodiment, the first substrate  20  is an array substrate, and the second substrate  40  is a color filter substrate. 
     Referring to  FIG. 7 , another embodiment of the disclosure further provides a manufacturing method of a liquid crystal display panel  100 , including the following steps: 
     S 201 : assembling the first substrate  20  and the second substrate  40  into a cell. 
     Specifically, an interlayer material of a black spacer photosensitive monomer is disposed between the first substrate  20  and the second substrate  40 . 
     S 202 : forming a polymer wall  30  on a side of the first substrate  20  facing the second substrate  40 . 
     The polymer wall  30  serves as a dual function of a photo spacer and a black matrix. The polymer wall  30  includes a photo spacer region and a black matrix region. 
     Specifically, the interlayer material containing the black photo spacer is selectively exposed, the film thickness varies in different transmittance regions, and a black photo spacer material is coated on the first substrate to be exposed and developed to form a black spacer having a multistage structure. 
     In the liquid crystal display panel  100  and the manufacturing method thereof according to the disclosure, the polymer wall  30  is formed between the first substrate  20  and the second substrate  40 . Since the connection area between the polymer wall  30  and the first substrate  20  is relatively large, the connection strength between the polymer wall  30  and the first substrate  20  is strengthened so as to prevent the polymer wall  30  from being easily separated from the first substrate  20 , thereby avoiding the light leakage and color shift phenomenon. In addition, the black photo spacer technology is used to form the polymer walls  30  of different heights on the first substrate  20  through a single process, the polymer walls  30  have the dual functions of the photo spacer and the black matrix, thereby reducing the cost and enhancing the light blocking effect and contrast. 
     The above is only the preferred embodiments of the disclosure, and certainly cannot be used to limit the scope of the disclosure. Those skilled in the art may understand that all or part of the processes of the above embodiments may be implemented, and equivalent changes made according to the claims of the disclosure are still within the scope of the disclosure.