Display panel and preparation method therefor

Abstract

Provided in the present invention are a display panel and a preparation method therefor. The display panel comprises: a light-emitting layer comprising a plurality of sub-pixels; a support column assembly comprising a first support column and a second support column, wherein the first support column is located on one side of the light-emitting layer, and the second support column is located on the side of the first support column facing away from the light-emitting layer; the projection of the first support column on the plane where the display panel is located is located within the projection of the second support column on the plane where the display panel is located; and the support column assembly is located between adjacent sub-pixels in the direction of the plane where the display panel is located; and a cathode layer comprising a first part and a second part that are separated from each other, wherein the first part is located on the same side of the light-emitting layer as the support column assembly, and the second part is located on the side of the second support column facing away from the first support column; and the first part comprises a plurality of through holes, and the through holes are formed at the bottom of the support column assembly. The present invention can isolate the cathode layer, form a full-surface mesh conduction, and reduce the lateral crosstalk current between the sub-pixels.

Description

Display panel and manufacturing method thereof TECHNICAL FIELD

[0001] The present application relates to the field of display panel structure, in particular to a display panel and a manufacturing method thereof. BACKGROUND

[0002] As a new generation of display technology, OLED (Organic Light Emitting Diode) display has the advantages of low power consumption, high color gamut, high brightness, high refresh rate, wide viewing angle, high response speed, etc. In particular, the advantage of high refresh rate makes OLED display more suitable for the display of mobile devices, so it is more and more widely used.

[0003] At present, the crosstalk of OLED products is serious at low gray scale, which causes the RGB three-color coordinates to deviate at low gray scale. The main reason for crosstalk is that the OLED three-color common layer and the cathode layer are deposited on the whole surface, and the cathode layer is a whole surface conduction. During the display process, the electric field transverse interference between adjacent sub-pixels causes the display panel to display distortion.

[0004] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present application, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art.

[0005] SUMMARY

[0006] Therefore, the present application provides a display panel and a manufacturing method thereof to at least solve the problem of the whole surface conduction of the cathode layer and the transverse crosstalk interference between sub-pixels causing the display panel to display distortion.

[0007] One aspect of the present application provides a display panel, comprising:

[0008] a light emitting layer comprising a plurality of sub-pixels;

[0009] a support column assembly comprising a first support column and a second support column, the first support column being located on one side of the light emitting layer, and the second support column being located on the side of the first support column away from the light emitting layer; a projection of the first support column on the plane of the display panel is contained in a projection of the second support column on the plane of the display panel; the support column assembly is located between adjacent sub-pixels in the direction of the plane of the display panel; and

[0010] a cathode layer comprising a first part and a second part separated from each other, the first part being located on the same side of the light emitting layer as the support column assembly, and the second part being located on the side of the second support column away from the first support column; the first part comprises a plurality of through holes, and the through holes are formed at the bottom of the support column assembly.

[0011] In some embodiments, the materials of the first support column and the second support column are different positive type first organic photoresist and positive type second organic photoresist respectively, the developing sensitivity of the first organic photoresist is greater than the second organic photoresist, and the exposed area of the first organic photoresist is equal to the second organic photoresist.

[0012] In some embodiments, the materials of the first support column and the second support column are the same positive type third organic photoresist, the developing sensitivity of the first support column is equal to the second support column, and the exposed area of the third organic photoresist of the first support column is greater than the second support column.

[0013] In some embodiments, the projection of the sub-pixel in the plane of the display panel is included in the projection of the cathode layer in the plane of the display panel.

[0014] The display panel further comprises a pixel definition layer located on the side of the first support column away from the second support column; the pixel definition layer comprises a plurality of pixel definition regions, and the sub-pixel is located in the pixel definition region.

[0015] In some embodiments, the sub-pixels include three types of red, green and blue, and in the direction of the plane of the display panel, at least part of the red sub-pixels and adjacent sub-pixels of other colors have the support column assembly.

[0016] In some embodiments, in the direction of the plane of the display panel, each red sub-pixel and adjacent sub-pixels of other colors have the support column assembly.

[0017] In some embodiments, in the direction of the plane of the display panel, green sub-pixels and adjacent blue sub-pixels also have the support column assembly.

[0018] In some embodiments, in the direction of the plane of the display panel, at least part of the green sub-pixels and adjacent sub-pixels of other colors have the support column assembly.

[0019] In some embodiments, in the direction of the plane of the display panel, at least part of the blue sub-pixels and adjacent sub-pixels of other colors have the support column assembly.

[0020] Another aspect of the present application also provides a preparation method of a display panel, for preparing the display panel described above, comprising the following steps:

[0021] coating the first organic photoresist;

[0022] coating the second organic photoresist on one side of the first organic photoresist;

[0023] exposing the first organic photoresist and the second organic photoresist using a first mask plate to control the area of the exposed region of the first organic photoresist to be equal to the second organic photoresist; wherein the materials of the first organic photoresist and the second organic photoresist are different positive organic photoresists respectively, and the development sensitivity of the first organic photoresist is greater than that of the second organic photoresist;

[0024] washing away the exposed regions of the first organic photoresist and the second organic photoresist using a developing solution, and solidifying to obtain the first support column and the second support column, which together form the support column assembly; wherein the projection of the first support column on the plane of the display panel is contained in the projection of the second support column on the plane of the display panel;

[0025] evaporating the sub-pixel between the support column assembly to form the light-emitting layer; and

[0026] evaporating the cathode layer on the side of the light-emitting layer close to the second support column; wherein the cathode layer comprises a first part and a second part separated from each other, the first part is formed on the same side of the light-emitting layer as the support column assembly, and the second part is formed on the side of the second support column away from the first support column; the first part comprises a plurality of through holes formed at the bottom of the support column assembly.

[0027] Another aspect of the present application also provides another method for manufacturing a display panel, for manufacturing the display panel described above, comprising the following steps:

[0028] coating the third organic photoresist which is positive;

[0029] performing first exposure on the third organic photoresist using a second mask plate to manufacture the first support column;

[0030] coating the third organic photoresist which is positive on one side of the third organic photoresist after exposure;

[0031] performing second exposure on the third organic photoresist using a third mask plate to manufacture the second support column, to control the area of the second exposure region to be smaller than that of the first exposure region;

[0032] washing away the exposed regions of the third organic photoresist using a developing solution, and solidifying to obtain the first support column and the second support column, which together form the support column assembly; wherein the projection of the first support column on the plane of the display panel is contained in the projection of the second support column on the plane of the display panel;

[0033] evaporate the sub-pixels between the support column assemblies to form the light-emitting layer; and

[0034] evaporate the cathode layer on the side of the light-emitting layer close to the second support column; wherein the cathode layer comprises a first part and a second part separated from each other, the first part is formed on the same side of the light-emitting layer as the support column assembly, and the second part is formed on the side of the second support column away from the first support column; the first part comprises a plurality of through holes formed at the bottom of the support column assembly.

[0035] The present application has at least the following advantages compared with the prior art:

[0036] The display panel and the preparation method thereof have the advantages that the T-shaped support column assembly is designed to be wide at the top and narrow at the bottom, so that the cathode layer is formed in two separated parts during evaporation and preparation, a meshed full-area conduction is formed, the transverse crosstalk current between the sub-pixels is reduced, and the display effect of the display panel at low gray scale is improved.

[0037] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0038] The drawings incorporated into the specification and forming part of the specification, show embodiments consistent with the present application, and together with the specification, serve to explain the principles of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0039] Fig. 1 shows a schematic diagram of a display panel provided by the present application;

[0040] Fig. 2 shows a schematic diagram of the structure of the support column and the cathode layer of a display panel provided by the present application;

[0041] Fig. 3 shows a schematic diagram of the top view arrangement of the support column of a display panel of a first embodiment provided by the present application;

[0042] Fig. 4 shows a schematic diagram of the top view arrangement of the support column of a display panel of a second embodiment provided by the present application;

[0043] Fig. 5 shows a schematic diagram of the top view arrangement of the support column of a display panel of a third embodiment provided by the present application;

[0044] Fig. 6 shows a schematic diagram of the top view arrangement of the support column of a display panel of a fourth embodiment provided by the present application;

[0045] Fig. 7 shows a schematic diagram of the top view arrangement of the support column of a display panel of a fifth embodiment provided by the present application;

[0046] Fig. 8 shows a flow chart of a method for manufacturing a display panel according to a sixth embodiment of the present application;

[0047] Fig. 9 shows a schematic view of the display panel before step S110 in Fig. 8;

[0048] Fig. 10 shows a schematic view of the display panel after step S110 in Fig. 8;

[0049] Fig. 11 shows a schematic view of the display panel after step S120 in Fig. 8;

[0050] Fig. 12 shows a schematic view of the display panel after step S130 in Fig. 8;

[0051] Fig. 13 shows a schematic view of the display panel after step S140 in Fig. 8;

[0052] Fig. 14 shows a flow chart of a method for manufacturing a display panel according to a seventh embodiment of the present application;

[0053] Fig. 15 shows a schematic view of the display panel before step S210 in Fig. 14;

[0054] Fig. 16 shows a schematic view of the display panel after step S210 in Fig. 14;

[0055] Fig. 17 shows a schematic view of the display panel after step S220 in Fig. 14;

[0056] Fig. 18 shows a schematic view of the display panel after step S230 in Fig. 14;

[0057] Fig. 19 shows a schematic view of the display panel after step S240 in Fig. 14;

[0058] Fig. 20 shows a schematic view of the display panel after step S250 in Fig. 14.

[0059] Reference numerals:

[0060] 1 light emitting layer

[0061] 11 sub-pixel

[0062] 2 support post assembly

[0063] 21 first support post

[0064] 22 second support post

[0065] 23 first organic photoresist

[0066] 24 second organic photoresist

[0067] 25 third organic photoresist

[0068] 3 cathode layer

[0069] 31 first part

[0070] 32 second part

[0071] 4 pixel definition layer

[0072] 5 planarization layer

[0073] 61 first mask plate

[0074] 62 second mask plate

[0075] 63 third mask plate

[0076] 7 display panel DETAILED DESCRIPTION

[0077] Example embodiments now will be described more fully hereinafter with reference to the accompanying drawings. Example embodiments, may, however, be implemented in many different forms and should not be construed as limited to the implementations set forth herein; rather, these implementations are provided as non-limiting examples so that this disclosure will be thorough and complete, and will fully convey the scope of the example embodiments to those skilled in the art. Like reference numerals refer to like elements throughout the figures, and descriptions of the same elements will not be repeated.

[0078] The terms "first", "second", and the like, as used in the description, do not imply any order, quantity, or importance, but are used to distinguish different components. Also, in the description of the present disclosure, the terms "upper", "lower", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are used only to facilitate description, and thus cannot be understood as indicating or implying that a device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus cannot be understood as limiting the present disclosure.

[0079] It should be noted that the embodiments of the present disclosure and the features in different embodiments can be combined with each other without conflict.

[0080] The present application provides a display panel and a preparation method thereof. The display panel comprises a light-emitting layer comprising a plurality of sub-pixels, a support column assembly comprising a first support column and a second support column, the first support column being located on one side of the light-emitting layer, and the second support column being located on a side of the first support column away from the light-emitting layer, a projection of the first support column on a plane of the display panel being contained in a projection of the second support column on the plane of the display panel, the support column assembly being located between adjacent sub-pixels in a direction of the plane of the display panel, and a cathode layer located on the same side of the light-emitting layer as the support column assembly, the cathode layer comprising a plurality of through holes formed at a bottom of the support column assembly. The display panel and the preparation method thereof of the present application form two separated parts of the cathode layer by designing a T-shaped support column assembly which is wide at the top and narrow at the bottom, so as to isolate the cathode layer, form a meshed whole conduction, reduce the horizontal crosstalk current between the sub-pixels, and improve the display effect of the display panel at low gray scale.

[0081] The specific embodiments of the present application are further described in detail below with reference to the accompanying drawings.

[0082] FIG. 1 shows a schematic diagram of a display panel provided by the present application; and FIG. 2 shows a structural schematic diagram of a support column and a cathode layer of a display panel provided by the present application.

[0083] One aspect of the present application provides a display panel 7 comprising a planarization layer 5, a pixel definition layer 4, a light-emitting layer 1, a cathode layer 3, and a support column assembly 2.

[0084] In some embodiments, the planarization layer 5 is used to planarize the lower film layer structure of the display panel 7, so as to facilitate the preparation of the pixel definition layer 4 and the light-emitting layer 1.

[0085] In some embodiments, the pixel definition layer 4 is located on one side of the planarization layer 5. The pixel definition layer 4 forms a plurality of protrusions on the planarization layer 5, and the grooves between the protrusions form a plurality of pixel definition regions, so as to facilitate the evaporation preparation of the sub-pixels 11, and the sub-pixels 11 are located in the pixel definition regions.

[0086] In some embodiments, the light-emitting layer 1 comprises a plurality of sub-pixels 11. When the display panel 7 is an OLED display panel, the sub-pixels 11 are OLED materials, but are not limited thereto.

[0087] In some embodiments, the support column assembly 2 comprises a first support column 21 and a second support column 22, the first support column 21 is located on one side of the light-emitting layer 1, and the second support column 22 is located on the side of the first support column 21 away from the light-emitting layer 1. The projection of the first support column 21 on the plane where the display panel 7 is located is contained in the projection of the second support column 22 on the plane where the display panel 7 is located, so as to form a T-shaped support column assembly 2 with a wide top and a narrow bottom, so that the cathode layer 3 forms a through hole when it is prepared by evaporation. The support column assembly 2 is located between adjacent sub-pixels 11 in the direction of the plane where the display panel 7 is located, so as to isolate the whole surface conduction of the cathode layer 3, reduce the horizontal crosstalk current between the sub-pixels 11, and improve the display effect of the display panel 7 at low gray scale.

[0088] In some embodiments, the shape of a cross section of the support column assembly 2 perpendicular to the display panel 7 is T-shaped, but not limited thereto.

[0089] In some embodiments, the cathode layer 3 comprises a first part 31 and a second part 32 separated from each other. The first part 31 is located on the same side of the light-emitting layer 1 as the support column assembly 2. The second part 32 is located on the side of the second support column 22 away from the first support column 21. The first part 31 comprises a plurality of through holes formed at the bottom of the support column assembly 2. It can be understood that due to the existence of the T-shaped support column assembly 2 with a wide top and a narrow bottom, the cathode layer 3 will be separated into the first part 31 and the second part 32 as described above when it is prepared by evaporation. The first part 31 of the cathode layer 3 is electrically connected to the light-emitting layer 1, and the second part 32 is not electrically connected to the light-emitting layer 1 and the first part 31. The first part 31 of the cathode layer 3 forms a horizontal isolation region through the support column assembly 2 and the through holes, so as to isolate the whole surface conduction of the cathode layer 3, reduce the horizontal crosstalk current between the sub-pixels 11, and improve the display effect of the display panel 7 at low gray scale.

[0090] In some embodiments, the projection of the second part 32 of the cathode layer 3 on the planarization layer 5 contains the projection of the through holes on the planarization layer 5. That is, due to the existence of the T-shaped support column assembly 2 with a wide top and a narrow bottom, the first part 31 and the second part 32 of the cathode layer 3 that should be connected are separated.

[0091] In some embodiments, the materials of the first support column 21 and the second support column 22 are different positive type first organic photoresist 23 and positive type second organic photoresist 24, respectively. The development sensitivity of the first organic photoresist 23 is greater than that of the second organic photoresist 24, and the exposure area of the first organic photoresist 23 is equal to that of the second organic photoresist 24, so as to form the T-shaped support column assembly 2 with a wide top and a narrow bottom.

[0092] In some embodiments, the first support column 21 and the second support column 22 are made of the same positive third organic photoresist 25, the first support column 21 has the same development sensitivity as the second support column 22, and the third organic photoresist 25 of the first support column 21 has a larger exposed area than the second support column 22, so as to form a T-shaped support column assembly 2 with a wide top and a narrow bottom.

[0093] In some embodiments, the projection of the sub-pixel 11 on the plane of the display panel 7 is contained in the projection of the cathode layer 3 on the plane of the display panel 7, so that the through hole is arranged between the sub-pixels 11 to interrupt the whole surface conduction of the cathode layer 3, reduce the horizontal crosstalk current between the sub-pixels 11, and improve the display effect of the display panel 7 at low gray scale.

[0094] In some embodiments, the support column assembly 2 is separated from the sub-pixel 11 based on the projection of the planarization layer 5, so that the through hole is arranged between the sub-pixels 11 to interrupt the whole surface conduction of the cathode layer 3, reduce the horizontal crosstalk current between the sub-pixels 11, and improve the display effect of the display panel 7 at low gray scale.

[0095] FIG. 3 shows a top view of the arrangement of the support columns of the display panel according to the first embodiment of the present application; FIG. 4 shows a top view of the arrangement of the support columns of the display panel according to the second embodiment of the present application; FIG. 5 shows a top view of the arrangement of the support columns of the display panel according to the third embodiment of the present application; FIG. 6 shows a top view of the arrangement of the support columns of the display panel according to the fourth embodiment of the present application; and FIG. 7 shows a top view of the arrangement of the support columns of the display panel according to the fifth embodiment of the present application.

[0096] Referring to FIGS. 3 to 7, the present application provides top view structural diagrams of the support column assembly 2 and the sub-pixel 11 of the display panel 7 according to five embodiments, but the five embodiments are only exemplary and do not represent that the present application only includes the five embodiments, as long as the following general description is met.

[0097] In some embodiments, the sub-pixels 11 include three types of red, green and blue. In the direction of the plane where the display panel is located, at least some of the red sub-pixels 11 have the support column assembly 2 between adjacent sub-pixels 11 of other colors. In the direction of the plane where the display panel is located, each of the red sub-pixels 11 has the support column assembly 2 between adjacent sub-pixels 11 of other colors. In the direction of the plane where the display panel is located, the green sub-pixels 11 also have the support column assembly 2 between adjacent blue sub-pixels 11. In the direction of the plane where the display panel is located, at least some of the green sub-pixels 11 have the support column assembly 2 between adjacent sub-pixels 11 of other colors; in the direction of the plane where the display panel is located, at least some of the blue sub-pixels 11 have the support column assembly 2 between adjacent sub-pixels 11 of other colors. The above is only a general description, and the following will be described with specific embodiments.

[0098] [First embodiment]

[0099] Referring to FIG. 3, in this embodiment, half of the red sub-pixels 11 have the support column assembly 2 between adjacent sub-pixels 11 of other colors, wherein two support column assemblies 2 surround one red sub-pixel 11. Half of the blue sub-pixels 11 have the support column assembly 2 between adjacent sub-pixels 11 of other colors, wherein two support column assemblies 2 surround one blue sub-pixel 11. Half of the green sub-pixels 11 have the support column assembly 2 between adjacent sub-pixels 11 of other colors, wherein two support column assemblies 2 surround one green sub-pixel 11. In each row of pixel arrangement, the support column assembly 2 surrounds the red sub-pixel 11, the blue sub-pixel 11 and the green sub-pixel 11 in turn. Specifically, each of the above-mentioned sub-pixels 11 surrounded by the support column assembly 2 is surrounded by the support column assembly 2 on four sides. The distribution of the support column assembly 2 allows the cathode layer 3 to form a through hole when prepared by evaporation, so as to interrupt the whole surface conduction of the cathode layer 3, reduce the horizontal crosstalk current between the sub-pixels 11, and improve the display effect of the display panel 7 at low gray scale.

[0100] [Second embodiment]

[0101] Referring to FIG. 4, in this embodiment, only the red sub-pixels 11 have the support column assembly 2 between adjacent sub-pixels 11 of other colors, wherein two support column assemblies 2 surround one red sub-pixel 11. The blue sub-pixels 11 and the green sub-pixels 11 are not provided with the support column assembly 2. Specifically, each of the above-mentioned red sub-pixels 11 surrounded by the support column assembly 2 is surrounded by the support column assembly 2 on four sides. Since the red sub-pixel 11 is a sub-pixel for high bright gray scale, the horizontal crosstalk at low gray scale is serious, so only the red sub-pixel 11 is interrupted to improve the display effect of the display panel 7 at low gray scale. At the same time, the number of through holes of the cathode layer 3 is reduced, and the structural strength of the cathode layer 3 is improved.

[0102] [Third embodiment]

[0103] Referring to FIG. 5, in the present embodiment, all the sub-pixels 11 have support column assemblies 2 between adjacent sub-pixels 11 of other colors, wherein two support column assemblies 2 semi-enclose one sub-pixel 11. Specifically, each of the sub-pixels 11 enclosed by the support column assemblies 2 has three aspects enclosed by the support column assemblies 2, and each of the sub-pixels 11 has two directions not enclosed. When arranged in an array, this embodiment can also make each two sub-pixels 11 be laterally partitioned, so as to improve the display effect of the display panel 7 at low gray scale.

[0104] [Fourth embodiment]

[0105] Referring to FIG. 6, in the present embodiment, all the sub-pixels 11 have support column assemblies 2 between adjacent sub-pixels 11 of other colors, wherein two support column assemblies 2 semi-enclose one sub-pixel 11. The difference from the third embodiment is that the shapes of the two support column assemblies 2 are different, and the degrees of semi-enclosing the sub-pixels 11 are different. Specifically, each of the sub-pixels 11 enclosed by the support column assemblies 2 has two aspects enclosed by the support column assemblies 2, and each of the sub-pixels 11 has two directions not enclosed. The present embodiment and the third embodiment can both make each two sub-pixels 11 be laterally partitioned when arranged in an array, so as to improve the display effect of the display panel 7 at low gray scale. Meanwhile, compared with the third embodiment, since the support column assemblies 2 are reused between each two adjacent sub-pixels 11, the total area of the through holes of the cathode layer 3 can be reduced, and the structural strength of the cathode layer 3 can be improved.

[0106] [Fifth embodiment]

[0107] Referring to FIG. 7, in the present embodiment, on the basis of the second embodiment that only all the red sub-pixels 11 have support column assemblies 2 between adjacent sub-pixels 11 of other colors, that is, only all the red sub-pixels 11 are surrounded by support column assemblies 2 on four sides, support column assemblies 2 are further arranged between the blue sub-pixels 11 and the green sub-pixels 11, and the support column assemblies 2 are reused for the blue sub-pixels 11 and the green sub-pixels 11, so as to further partition the whole surface conduction of the cathode layer 3, reduce the lateral crosstalk current between the sub-pixels 11, and improve the display effect of the display panel 7 at low gray scale.

[0108] The display panel 7 of the present application can make the cathode layer 3 form two separated parts when prepared by evaporation, so as to partition the whole surface conduction of the cathode layer 3, form a mesh surface conduction, reduce the lateral crosstalk current between the sub-pixels 11, and improve the display effect of the display panel 7 at low gray scale.

[0109] [Sixth embodiment]

[0110] FIG. 8 shows a flow chart of a method for manufacturing a display panel according to a sixth embodiment of the present application; FIG. 9 shows a schematic view of a display panel before step S110 in FIG. 8; FIG. 10 shows a schematic view of a display panel after step S110 in FIG. 8; FIG. 11 shows a schematic view of a display panel after step S120 in FIG. 8; FIG. 12 shows a schematic view of a display panel after step S130 in FIG. 8; and FIG. 13 shows a schematic view of a display panel after step S140 in FIG. 8.

[0111] Referring to FIGS. 8 to 13, based on the same inventive concept, another aspect of the present application provides a method for manufacturing a display panel, which is used to manufacture the display panel 7 described above, and includes the following steps:

[0112] S110, coating a first organic photoresist 23;

[0113] S120, coating a second organic photoresist 24 on one side of the first organic photoresist 23;

[0114] S130, exposing the first organic photoresist 23 and the second organic photoresist 24 using a first mask plate 61 to control the area of the exposed region of the first organic photoresist 23 to be equal to that of the second organic photoresist 24; wherein the materials of the first organic photoresist 23 and the second organic photoresist 24 are different positive organic photoresists, and the developing sensitivity of the first organic photoresist 23 is greater than that of the second organic photoresist 24;

[0115] S140, washing away the exposed regions of the first organic photoresist 23 and the second organic photoresist 24 using a developing solution, and solidifying to obtain the first support column 21 and the second support column 22, which together form the support column assembly 2; wherein the projection of the first support column 21 on the plane of the display panel is included in the projection of the second support column 22 on the plane of the display panel.

[0116] S150, evaporating the sub-pixel 11 between the support column assembly 2 to form the light-emitting layer 1; and

[0117] S160, evaporating the cathode layer 3 on the side of the light-emitting layer 1 close to the second support column 22; wherein the cathode layer 3 includes a first portion 31 and a second portion 32 separated from each other, the first portion 31 is formed on the same side of the light-emitting layer 1 as the support column assembly 2, and the second portion 32 is formed on the side of the second support column 22 away from the first support column 21; the first portion 31 includes a plurality of through holes formed at the bottom of the support column assembly 2.

[0118] It is worth noting that S110-S160 are merely labels of steps, which are used for subsequent reference and avoiding repeated writing, and are not used for limiting the implementation order of each step of the method. In other embodiments, the above steps of the method can also be written in a different order, and are not limited thereto. The subsequent step labels in the present application all have the same meaning, and the repeated parts will not be described again.

[0119] Referring to FIGS. 9-11, in the above steps S110 and S120, the materials for preparing the first support column 21 and the second support column 22 can be different positive type first organic photoresist 23 and positive type second organic photoresist 24, such as Toray DL series positive type organic photoresist. Among them, the development sensitivity of the first organic photoresist 23 is greater than that of the second organic photoresist 24, and the exposure area of the first organic photoresist 23 is equal to that of the second organic photoresist 24, so as to form a T-shaped support column assembly 2 with a wide upper part and a narrow lower part. The exposed part of the positive type organic photoresist dissolves in the developing solution, while the unexposed part does not dissolve in the developing solution.

[0120] Referring to FIG. 12, in the above step S130, during exposure, the positive type first organic photoresist 23 and the positive type second organic photoresist 24 are located below the first mask plate 61, and the light source is irradiated from the first mask plate 61 to the bottom. The first mask plate 61 is provided with a shield at the position where the support column assembly 2 is needed to be formed, and the shape of the shield can be designed according to the shape of the support column assembly 2. For details, reference can be made to the embodiments in FIGS. 3-7, or the shape of the support column assembly 2 in other embodiments. Since the development sensitivity of the first organic photoresist 23 is greater than that of the second organic photoresist 24, and the exposed part of the positive type organic photoresist dissolves in the developing solution, while the unexposed part does not dissolve in the developing solution, the unexposed area is left. Further, in the unexposed area, the width of the remaining second organic photoresist 24 is greater than that of the remaining first organic photoresist 23, thereby forming a T-shaped support column assembly 2 with a wide upper part and a narrow lower part. In other embodiments, negative type organic photoresist or other preparation methods can also be used, as long as a T-shaped support column assembly 2 with a wide upper part and a narrow lower part is finally formed.

[0121] Referring to FIG. 13, in the above step S140, since the exposed part of the positive type organic photoresist dissolves in the developing solution, while the unexposed part does not dissolve in the developing solution, the exposed areas of the first organic photoresist 23 and the second organic photoresist 24 are washed away using the developing solution, so as to finally form a T-shaped support column assembly 2 with a wide upper part and a narrow lower part, and form a through hole in the cathode layer 3 during evaporation preparation.

[0122] In step S150, the sub-pixels 11 are evaporated between the support column assemblies 2 to form the light-emitting layer 1. The light-emitting layer 1 includes a plurality of sub-pixels 11. When the display panel 7 is an OLED display panel, the sub-pixels 11 are OLED materials, but are not limited thereto. Before the light-emitting layer 1 is prepared, a pixel definition layer 4 is also prepared, which is located on one side of the planarization layer 5. The pixel definition layer 4 forms a plurality of protrusions on the planarization layer 5, and the grooves between the protrusions form a plurality of pixel definition areas, so as to facilitate the evaporation preparation of the sub-pixels 11, which are located in the pixel definition areas.

[0123] In step S160, since the cathode layer 3 is prepared by evaporation, when the support column assembly 2 is in the T-shaped structure with the upper part wider and the lower part narrower, the cathode layer 3 cannot be completely connected at the support column assembly 2, forming the first part 31 and the second part 32 separated from each other, and further forming a through hole at the bottom of the support column assembly 2 to block the whole surface conduction of the cathode layer 3, form a mesh surface conduction, reduce the horizontal crosstalk current between the sub-pixels 11, and improve the display effect of the display panel 7 at low gray scale.

[0124] Other aspects of the method embodiment can refer to the above-mentioned display panel 7 embodiment, and repeated parts will not be described herein.

[0125]

Seventh Embodiment

[0126] FIG. 14 shows a flowchart of a preparation method of a display panel according to a seventh embodiment of the present application; FIG. 15 shows a structural schematic diagram of the display panel before step S210 in FIG. 14; FIG. 16 shows a structural schematic diagram of the display panel after step S210 in FIG. 14; FIG. 17 shows a structural schematic diagram of the display panel after step S220 in FIG. 14; FIG. 18 shows a structural schematic diagram of the display panel after step S230 in FIG. 14; FIG. 19 shows a structural schematic diagram of the display panel after step S240 in FIG. 14; and FIG. 20 shows a structural schematic diagram of the display panel after step S250 in FIG. 14.

[0127] Referring to FIGS. 14 to 20, based on the same inventive concept, another aspect of the present application further provides another preparation method of a display panel, which is used to prepare the above-mentioned display panel 7, and includes the following steps:

[0128] S210, coating a third organic photoresist 25 of a positive type;

[0129] S220, performing first exposure on the third organic photoresist 25 by using a second mask plate 62, so as to prepare the first support column 21;

[0130] S230, coating the third organic photoresist 25 of a positive type on one side of the exposed third organic photoresist 25 again;

[0131] S240, using the third mask plate 63 to perform second exposure on the third organic photoresist 25 to prepare the second support column 22, so as to control the area of the second exposure region to be less than the area of the first exposure region;

[0132] S250, using a developing solution to wash away the exposed region of the third organic photoresist 25, and solidifying to obtain the first support column 21 and the second support column 22, which together form the support column assembly 2; wherein the projection of the first support column 21 on the plane of the display panel is contained in the projection of the second support column 22 on the plane of the display panel;

[0133] S260, evaporating the sub-pixel 11 between the support column assembly 2 to form the light-emitting layer 1; and

[0134] S270, evaporating the cathode layer 3 on the side of the light-emitting layer 1 close to the second support column 22; wherein the cathode layer 3 includes a first part 31 and a second part 32 separated from each other, the first part 31 is formed on the same side of the light-emitting layer 1 as the support column assembly 2, and the second part 32 is formed on the side of the second support column 22 away from the first support column 21; the first part 31 includes a plurality of through holes formed at the bottom of the support column assembly 2.

[0135] Referring to FIGS. 15-16, in the above step S210, the material for preparing the first support column 21 can be a positive third organic photoresist 25, such as Toray DL series positive organic photoresist.

[0136] Referring to FIG. 17, in the above step S220, during the first exposure, the positive third organic photoresist 25 for preparing the first support column 21 is located below the second mask plate 62, and the light source is irradiated from the upper side of the second mask plate 62 to the lower side. The second mask plate 62 is provided with a shielding at the position where the first support column 21 is to be formed, and the shape of the shielding can be designed according to the shape of the first support column 21. For details, reference can be made to the embodiments in FIGS. 3-7, or the shape of the support column assembly 2 of other embodiments. Since the exposed part of the positive organic photoresist dissolves in the developing solution, and the unexposed part does not dissolve in the developing solution, the unexposed region is left after the developing solution is used for cleaning.

[0137] Referring to FIG. 18, in the above step S230, the material for preparing the second support column 22 can be the same positive third organic photoresist 25 as the first support column 21. In this way, the developing sensitivity of the first support column 21 is equal to that of the second support column 22.

[0138] Referring to FIG. 19, in the step S240, the third positive photoresist 25 for preparing the second support column 22 is located below the third mask plate 63, and the light source is irradiated from the top of the third mask plate 63. The third mask plate 63 is provided with a shielding part at the position where the second support column 22 is to be formed. The shape of the shielding part can be designed according to the shape of the second support column 22. For example, the shape of the support column assembly 2 can refer to the embodiments shown in FIGS. 3 to 7, or other embodiments. Since the exposed part of the positive photoresist is dissolved in the developing solution, and the unexposed part is not dissolved in the developing solution, the unexposed part is left after the developing solution is used to clean the exposed part. Since the area of the shielding part in the first exposure is smaller than that in the second exposure, the width of the second support column 22 formed finally is greater than that of the first support column 21.

[0139] Referring to FIG. 20, in the step S250, since the exposed part of the positive photoresist is dissolved in the developing solution, and the unexposed part is not dissolved in the developing solution, the third photoresist 25 used for preparing the first support column 21 and the second support column 22 is washed away by the developing solution, so as to obtain the first support column 21 and the second support column 22, and finally form the T-shaped support column assembly 2 with the width of the top being greater than that of the bottom.

[0140] In the step S260, the sub-pixels 11 are evaporated between the support column assemblies 2 to form the light-emitting layer 1. The light-emitting layer 1 includes a plurality of sub-pixels 11. When the display panel 7 is an OLED display panel, the sub-pixels 11 are OLED materials, but are not limited thereto. Before the light-emitting layer 1 is prepared, the pixel definition layer 4 is also prepared, and the pixel definition layer 4 is located on one side of the planarization layer 5. The pixel definition layer 4 forms a plurality of protrusions on the planarization layer 5, and the grooves between the protrusions form a plurality of pixel definition areas, so as to facilitate the evaporation preparation of the sub-pixels 11, and the sub-pixels 11 are located in the pixel definition areas.

[0141] In the step S270, since the cathode layer 3 is prepared by evaporation, when the support column assembly 2 is in the T-shaped form with the width of the top being greater than that of the bottom, the cathode layer 3 cannot be completely connected at the support column assembly 2, and a through hole is formed at the bottom of the support column assembly 2, so as to cut off the whole surface conduction of the cathode layer 3, reduce the transverse crosstalk current between the sub-pixels 11, and improve the display effect of the display panel 7 at low gray scale.

[0142] Other aspects of the method embodiment can refer to the above-mentioned embodiments of the display panel 7. The repeated parts will not be described again.

[0143] The preparation method of the display panel of the present application forms two separated parts of the cathode layer 3 during the evaporation preparation by designing the T-shaped support column assembly 2 which is wide at the top and narrow at the bottom, so as to interrupt the whole surface conduction of the cathode layer 3, form the netted surface conduction, reduce the horizontal crosstalk current between the sub-pixels 11, and improve the display effect of the display panel 7 at low gray scale.

[0144] In summary, the display panel and the preparation method thereof of the present application form two separated parts of the cathode layer during the evaporation preparation by designing the T-shaped support column assembly which is wide at the top and narrow at the bottom, so as to interrupt the cathode layer, form the netted whole surface conduction, reduce the horizontal crosstalk current between the sub-pixels, and improve the display effect of the display panel at low gray scale.

[0145] The above is the further detailed description of the present application in combination with the specific optional embodiments, and cannot be deemed as the limitation of the specific implementation of the present application to these descriptions. For the ordinary skilled in the art to which the present application belongs, some simple deductions or replacements can be made without departing from the concept of the present application, and all of them shall be deemed as the protection scope of the present application.

Claims

1. A display panel, characterized in that: include: a light-emitting layer comprising a plurality of sub-pixels; A support column assembly includes a first support column and a second support column, wherein the first support column is located on one side of the light-emitting layer, and the second support column is located on a side of the first support column away from the light-emitting layer; The projection of the first support column on the plane where the display panel is located is included in the projection of the second support column on the plane where the display panel is located; the support column assembly is located between adjacent sub-pixels in the direction of the plane where the display panel is located; as well as The cathode layer includes a first part and a second part separated from each other, the first part is located on the same side of the light-emitting layer as the support column assembly, and the second part is located on the side of the second support column away from the first support column; the first part includes a plurality of through holes, and the through holes are formed at the bottom of the support column assembly.

2. The display panel according to claim 1, wherein: The materials of the first supporting column and the second supporting column are different positive first organic photoresist and positive second organic photoresist respectively. The development sensitivity of the first organic photoresist is greater than that of the second organic photoresist, and the exposure area of ​​the first organic photoresist is equal to that of the second organic photoresist.

3. The display panel according to claim 1, wherein: The first support column and the second support column are made of the same positive third organic photoresist, the development sensitivity of the first support column is equal to that of the second support column, and the exposure area of ​​the third organic photoresist of the first support column is larger than that of the second support column.

4. The display panel according to claim 1, wherein: The projection of the sub-pixel on the plane where the display panel is located includes the projection of the cathode layer on the plane where the display panel is located; The display panel further includes a pixel definition layer located on a side of the first support column away from the second support column; the pixel definition layer includes a plurality of pixel definition areas, and the sub-pixels are located in the pixel definition areas.

5. The display panel according to claim 1, wherein: The sub-pixels include three types: red, green and blue. In the direction of the plane where the display panel is located, the support column assembly is provided between at least some of the red sub-pixels and adjacent sub-pixels of other colors.

6. The display panel according to claim 5, wherein: In the direction of the plane where the display panel is located, the support column assembly is provided between each red sub-pixel and adjacent sub-pixels of other colors.

7. The display panel according to claim 6, wherein: In the direction of the plane where the display panel is located, the green sub-pixel and the adjacent blue sub-pixel also have the supporting column assembly.

8. The display panel according to claim 5, wherein: In the direction of the plane where the display panel is located, the support column assembly is provided between at least part of the green sub-pixels and adjacent sub-pixels of other colors; In the direction of the plane where the display panel is located, the support column assembly is located between at least part of the blue sub-pixels and adjacent sub-pixels of other colors.

9. A method for preparing a display panel, for preparing the display panel according to claim 2, characterized in that: The following steps are involved: applying the first organic photoresist; coating the second organic photoresist on one side of the first organic photoresist; exposing the first organic photoresist and the second organic photoresist using a first mask to control the exposure area of ​​the first organic photoresist to be equal to the area of ​​the second organic photoresist; wherein the first organic photoresist and the second organic photoresist are made of different positive organic photoresists, and the development sensitivity of the first organic photoresist is greater than that of the second organic photoresist; Using a developer to wash away the exposed areas of the first organic photoresist and the second organic photoresist, and curing to obtain the first support column and the second support column, which together form the support column assembly; wherein the projection of the first support column on the plane where the display panel is located is included in the projection of the second support column on the plane where the display panel is located; Vapor-depositing the sub-pixels between the support column assemblies to form the light-emitting layer; and The cathode layer is evaporated on the side of the light-emitting layer close to the second support column; wherein the cathode layer includes a first part and a second part separated from each other, the first part is formed on the same side of the light-emitting layer as the support column assembly, and the second part is formed on the side of the second support column away from the first support column; the first part includes a plurality of through holes, and the through holes are formed at the bottom of the support column assembly.

10. A method for preparing a display panel, for preparing the display panel according to claim 3, characterized in that: The following steps are involved: Applying the third positive organic photoresist; performing a first exposure on the third organic photoresist using a second mask to prepare the first support pillar; Re-coating the positive type third organic photoresist on one side of the exposed third organic photoresist; Expose the third organic photoresist for a second time using a third mask to prepare the second support pillar, so as to control the area of ​​the second exposure region to be smaller than the area of ​​the first exposure region; Washing away the exposed area of ​​the third organic photoresist with a developer, and curing the first support column and the second support column to obtain the first support column and the second support column, which together form the support column assembly; wherein the projection of the first support column on the plane where the display panel is located is included in the projection of the second support column on the plane where the display panel is located; Vapor-depositing the sub-pixels between the support column assemblies to form the light-emitting layer; and The cathode layer is evaporated on the side of the light-emitting layer close to the second support column; wherein the cathode layer includes a first part and a second part separated from each other, the first part is formed on the same side of the light-emitting layer as the support column assembly, and the second part is formed on the side of the second support column away from the first support column; the first part includes a plurality of through holes, and the through holes are formed at the bottom of the support column assembly.

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