CN112201675B

CN112201675B - Display substrate and preparation method thereof

Info

Publication number: CN112201675B
Application number: CN202010970601.0A
Authority: CN
Inventors: 夏曾强; 周小康; 胡小叙; 艾经伟; 王虎
Original assignee: Yungu Guan Technology Co Ltd
Current assignee: Yungu Guan Technology Co Ltd
Priority date: 2020-09-15
Filing date: 2020-09-15
Publication date: 2022-09-27
Anticipated expiration: 2040-09-15
Also published as: CN112201675A

Abstract

The invention discloses a display substrate and a preparation method thereof, wherein the display substrate comprises a substrate and a pixel definition layer arranged on one side of the substrate, the pixel definition layer comprises a pixel definition area and a pixel area, and the display substrate further comprises: a separation layer formed on a side of the pixel defining region away from the substrate; the carrier function layer is formed on the surface of one side, away from the pixel defining layer, of the separation layer; the separating layer enables the carrier functional layer to form a discontinuous pattern structure on the pixel defining area and the surface of one side, far away from the substrate, of the pixel area.

Description

Display substrate and preparation method thereof

Technical Field

The invention relates to the technical field of display, in particular to a display substrate and a preparation method thereof.

Background

An Organic Light Emitting Diode (OLED) is an active Light Emitting display device, and has the advantages of self-luminescence, wide viewing angle, high contrast, low power consumption, and very high response speed. With the continuous development of display technology, OLED technology is increasingly applied to flexible display devices.

At present, an evaporation process combining an exposure Mask (CMM for short) and a Fine Metal Mask (FMM) is commonly used for preparing a charge transport layer in a traditional OLED self-luminous device, but a carrier function layer of the OLED device manufactured by the evaporation process has a cross talk (cross talk) condition between pixels, that is, when a certain pixel is lighted, other pixels around the lighted pixel have a weak luminescence condition. That is, charge carriers injected into a lit pixel may leak into other pixels in the vicinity through the carrier function layer.

In view of the foregoing, there is a need for a new OLED display substrate and a method for manufacturing the same, which can improve the lateral crosstalk of the pixels and simplify the manufacturing process.

Disclosure of Invention

The present invention is directed to a display panel capable of preventing or reducing crosstalk between charge transport layers and a method of manufacturing the same.

In order to achieve one of the above objects, an embodiment of the present invention provides a display substrate, which includes a substrate and a pixel definition layer disposed on one side of the substrate, where the pixel definition layer includes a pixel definition region and a pixel region, and the display substrate further includes: a separation layer formed on a side of the pixel defining region away from the substrate; the carrier function layer is formed on the surface of one side, away from the pixel defining layer, of the separation layer; wherein the separation layer causes the carrier function layer to form a discontinuous pattern structure on the pixel defining region and a surface of the pixel region on a side away from the substrate.

Alternatively, the material of the separation layer is a fluorine-containing substituent selected from an alkyl chain having 3 or more carbon atoms, a silane chain having 3 or more silicon atoms, or a mixture of both.

As an optional technical solution, a surface of one side of the pixel defining area, which is far away from the substrate, includes a first protrusion and a second protrusion, the first protrusion and the second protrusion are arranged at an interval, and a first recess is provided between the first protrusion and the second protrusion.

As an optional technical solution, a depth of the first concave portion in a direction perpendicular to the display substrate is 0.1 μm to 0.5 μm.

As an alternative solution, a cross-sectional shape of the first concave portion along a direction perpendicular to the display substrate includes at least one of a U shape, a rectangular shape, a V shape, a regular trapezoid shape, and an inverted trapezoid shape.

As an optional technical solution, the first protrusion and the second protrusion are respectively disposed around the pixel region, and the first recess is a groove disposed around the pixel region.

As an optional technical solution, the surface of one side of the pixel defining area, which is far away from the substrate, further includes at least one third protrusion, and the at least one third protrusion is disposed in the first recess, wherein a third protrusion surface of each third protrusion, which is far away from the substrate, is higher than a first protrusion surface of the first protrusion, which is far away from the substrate, and the third protrusion surface is higher than a second protrusion surface of the second protrusion, which is far away from the substrate.

The present invention further provides a method for manufacturing a display substrate, the display substrate including a substrate and a pixel defining layer disposed on one side of the substrate, the method comprising:

s1, patterning the pixel definition layer to form a plurality of pixel areas and a plurality of pixel definition areas, wherein the pixel areas are a plurality of openings, and each pixel definition area is arranged between any adjacent pixel areas;

s2, providing a separation layer solution, and immersing the pixel definition region into the separation layer solution, wherein the depth of the pixel definition region immersed under the liquid level of the separation layer solution is less than or equal to 0.1-1 μm; and

s3, turning over the display substrate in the S2, and drying the separation layer solution in vacuum to form a separation layer on the surface of one side, away from the substrate, of the pixel defining area; and

s4, forming a carrier function layer on the surface of one side, away from the substrate, of the pixel defining layer;

wherein the separation layer causes the carrier function layer to form a discontinuous pattern structure on the pixel defining region and a surface of the pixel region on a side away from the substrate.

As an optional technical solution, the S1 further includes: s11: patterning the pixel defining area to form a first protrusion and a second protrusion which are arranged at intervals; the S2 further includes: s21: immersing the first bulges and the second bulges into the separating layer solution, wherein the depth of the first bulges and the second bulges immersed under the liquid surface of the separating layer solution is less than or equal to 0.1-1 mu m; wherein the first protrusion and the second protrusion include a first recess therebetween.

As an optional technical solution, the S1 further includes: s12: patterning the pixel defining area to form a first protrusion, a second protrusion and at least one third protrusion which are arranged at intervals, wherein the third protrusion surface of each third protrusion, which is far away from the substrate, is higher than the first protrusion surface of the first protrusion, which is far away from the substrate, and the second protrusion surface of the second protrusion, which is far away from the substrate; the S2 further includes: s22: and immersing the third protrusion into the separation layer solution, wherein the depth of the third protrusion immersed below the liquid level of the separation layer solution is less than or equal to 0.1-1 μm.

Compared with the prior art, the invention provides the display substrate and the preparation method thereof, wherein the separation layer is formed on the surface of one side, away from the substrate, of the pixel definition layer of the display substrate, and the separation layer enables the pixel definition region and the pixel region of the pixel definition layer to form the discontinuous carrier function layer, so that the transverse transmission of carriers in the carrier function layer between adjacent pixels is disconnected, and the problem of transverse crosstalk when the pixels are lightened is solved. Further, the structure of the protrusion of the pixel defining region is optimized, so that the separation layer is ensured not to flow into the pixel region, and the problem of abnormal filling of the light emitting layer in the pixel region due to the existence of the separation layer in the pixel region is avoided.

Drawings

Fig. 1 is a schematic cross-sectional view of a display substrate according to an embodiment of the invention.

Fig. 2 is a schematic partial top view of the uncoated functional layer of the display substrate of fig. 1.

Fig. 3A to 3H are schematic views illustrating a process of manufacturing the display substrate of fig. 1.

Fig. 4A to 4B are schematic views of a display substrate according to another embodiment of the invention.

Fig. 5A to 5B are schematic views of a display substrate according to another embodiment of the invention.

Fig. 6A to 6D are schematic cross-sectional views of a display substrate with a concave portion having different cross-sectional shapes according to another embodiment of the present invention.

Fig. 7 is a flowchart of a method for manufacturing a display panel according to the present invention.

Detailed Description

The present invention will be described in detail below with reference to specific embodiments shown in the drawings. These embodiments are not intended to limit the present invention, and structural, methodological, or functional changes made by those skilled in the art according to these embodiments are included in the scope of the present invention.

It is to be noted that, unless otherwise defined, all terms (including technical and scientific terms) used in the embodiments of the present invention have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

For example, the terms "first," "second," and the like as used in the description and in the claims of the present patent application do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "one side", "the other side" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only used for convenience of simplifying the description of the technical solution of the present invention, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present invention.

An OLED (organic light emitting diode) is an ultra-thin self-luminescent device, consisting of multiple layers of organic materials between two electrodes. The light emitting layer is sandwiched between the current carrier function layers and is positioned in the center of the device; the carrier function layer comprises a stack of: a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), an Electron Injection Layer (EIL), and/or an Electron Transport Layer (ETL).

In most conventional OLED device structures, commonly used red, green, and blue (RGB) light emitting units share a Hole Injection Layer (HIL). When a turn-on voltage is applied to one of the light emitting cells, the adjacent light emitting cells of the other or two colors may be lighted due to the high carrier mobility of the hole injection layer, thereby generating lateral Crosstalk (Crosstalk).

At present, in order to achieve the purpose of reducing lateral crosstalk (cross talk), a partition Design is often made on a Pixel Design Layer (PDL) of a display substrate, and the partition Design includes: forming a deep groove with high drop height on the pixel defining layer; or, etching the carrier function layer to physically separate or locally modify the charge transport layer. The partition design usually needs an evaporation process or a gas treatment process, so that the process requirement is high, and the number of photomask steps is increased, so that the preparation cost of the OLED display screen is increased. In addition, the addition of masks and gas treatment processes results in lower material utilization.

The invention provides a display substrate and a preparation process thereof.A separation layer is formed on a pixel definition region of a pixel definition layer, and a carrier function layer on the separation layer forms a discontinuous pattern structure on the pixel definition region and one side of the pixel region of the pixel definition layer, so that the aims of overcoming the transverse crosstalk between pixels and simplifying the preparation process are fulfilled.

As shown in fig. 1 and fig. 2, a display substrate 100 according to the present invention includes a substrate 10 and a pixel definition layer 30 disposed on one side of the substrate 10, wherein the pixel definition layer 30 is divided into a pixel definition region 32 and a pixel region 31; the separation layer 71 is formed on the side of the pixel defining region 31 away from the substrate 10; a carrier function layer (not shown) is formed on a surface of the separation layer 71 on a side away from the pixel defining layer 30; the separation layer 71 causes the carrier function layer to form a discontinuous pattern structure on the surfaces of the pixel defining region 32 and the pixel region 31 on the side away from the substrate 10.

In this embodiment, the material of the separation layer 71 is selected from a fluorine-containing substituent containing an alkyl chain of 3 or more carbon atoms, a fluorine-containing substituent containing a silane chain of 3 or more silicon atoms, or a mixture of the two. The fluorine-containing substituent may be a perfluoro substituent or a partial fluorine-containing substituent.

When a carrier functional layer is subsequently vapor-deposited on the surface of the pixel defining layer 30 on the side away from the substrate 10 by an evaporation process, due to the presence of the separation layer 71 having low surface energy, the layer of the carrier functional layer including the Hole Injection Layer (HIL) and/or the Hole Transport Layer (HTL) in the region where the separation layer 71 is located becomes discontinuous, i.e., the region of the Hole Injection Layer (HIL) and/or the Hole Transport Layer (HTL) corresponding to the separation layer 71 is interrupted and electrically isolated from each other; meanwhile, also because the separation layer 71 is disposed between any adjacent pixels, that is, the Hole Injection Layer (HIL) and/or the Hole Transport Layer (HTL) between any adjacent pixels are electrically isolated from each other by being disconnected from each other, when one pixel is lit, holes injected into the Hole Injection Layer (HIL) and/or the Hole Transport Layer (HTL) in a selected pixel cannot laterally migrate to the Hole Injection Layer (HIL) and/or the Hole Transport Layer (HTL) in an adjacent unselected pixel, and thus, a lateral crosstalk (crosstalk talk) phenomenon between pixels may be inhibited or reduced.

In the present invention, the problem of inter-pixel signal lateral crosstalk (cross talk) is caused by the occurrence of lateral leakage in the current carrier function layer in the OLED device, where "lateral" refers to a direction perpendicular to the layer direction of the light emitting function layer, that is, a direction from one electrode to the opposite electrode in one OLED device is a longitudinal direction, and an opposite direction parallel to the layer direction of the current carrier function layer is a lateral direction, with respect to the light emitting direction of the OLED device.

In the present embodiment, the carrier function layer is, for example, a Hole Injection Layer (HIL) and/or a Hole Transport Layer (HTL), and is preferably a Hole Injection Layer (HIL).

As shown in fig. 1, the display substrate 100 of the present invention is an OLED display substrate, and further includes a transistor array layer 20 composed of a plurality of transistors arranged in an array for controlling each OLED device between the substrate 10 and the pixel defining layer 30.

The pixel regions 31 of the pixel defining layer 30 are openings, the OLED light emitting device layer is disposed in the pixel regions 31, the pixel regions 31 are arranged in an array on the substrate 10, wherein a pixel defining region 32 is disposed between any adjacent pixel regions 31, or a pixel region 31 is defined between any adjacent pixel defining regions 32 at any interval.

In addition, the display substrate 100 further includes a first electrode (not shown) disposed between the transistor array layer 20 and the pixel defining layer 30 and corresponding to each of the pixel regions 31 on the substrate 10, at least a partial region of the first electrode being exposed from each of the pixel regions 31; an OLED light-emitting device layer (not shown) disposed on a side of the pixel defining layer 30 away from the substrate 10, the OLED light-emitting device layer including a plurality of stacked layers of a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), a light-emitting layer, an Electron Transport Layer (ETL), and an Electron Injection Layer (EIL), the light-emitting layer being sandwiched between the Hole Transport Layer (HTL) and the Electron Transport Layer (ETL), wherein at least one of the Hole Injection Layer (HIL) and/or the Hole Transport Layer (HTL) is disposed on a side surface of the pixel defining layer 30 away from the substrate 10; and a second electrode (not shown) disposed on a side of the OLED light emitting device layer away from the substrate, wherein if the first electrode is an anode, the second electrode is a cathode. In an embodiment, when the anode of each OLED device is made as separate electrodes spaced apart and not in contact with each other, the second electrode may be laid on the light emitting function layer in a whole layer for simplifying the process, that is, the cathode of each OLED device is an integrated structure connected together.

With continued reference to fig. 1 and 2, a side of the pixel defining region 32 of the pixel defining layer 30 away from the substrate 10 includes a first protrusion 33 and a second protrusion 34 arranged at an interval, and a first recess 35 is included between the first protrusion 33 and the second protrusion 34. In the top view of fig. 2, the first concave portion 35 surrounds the groove structure of the pixel region 31, and the depth D1 (shown in fig. 3F) of the first concave portion 35 is 0.1 μm to 0.5 μm.

In this embodiment, the first concave portion 35 is a groove of a zigzag structure surrounding the pixel region 31, but not limited thereto. In other embodiments of the present invention, the first concave portion may be a groove structure of another shape, such as a ring shape, a prism shape, and the like, surrounding the pixel region in a top view.

As shown in fig. 1, the first recess 35 has a U-shaped cross section in a direction perpendicular to the substrate 10, but the shape is not limited thereto. As shown in fig. 6A to 6D, in other embodiments of the present invention, the pixel defining layer 3100 of the display substrate is patterned to form the pixel region 31 and the pixel defining region 320, and the cross-sectional shapes of the first

concave portions

3301, 3302, 3303, 3304 on the side of the pixel defining region 320 away from the substrate 10 in the direction perpendicular to the substrate are respectively rectangular, V-shaped, trapezoidal, and inverted trapezoidal.

When the cross section of the first recess 3203 is trapezoidal, during evaporation of a Hole Injection Layer (HIL) and/or a Hole Transport Layer (HTL) in a charge transport layer, since an opening at the upper portion of the trapezoid is small, a part of the Hole Injection Layer (HIL) and/or the Hole Transport Layer (HTL) is shielded by a first protruding surface of a first protrusion and a second protruding surface of a second protrusion at two sides of the first recess 3303 and cannot enter the trapezoid, and by combining with a separation layer (not shown) design in the trapezoid, a film layer including a carrier function layer of the Hole Injection Layer (HIL) and/or the Hole Transport Layer (HTL) at the pixel defining region 320 can be better separated, and thus the problem of lateral crosstalk between pixels is better solved.

As shown in fig. 1, the separation layer 71 completely covers the first protrusion surface of the first protrusion 33 away from the substrate 10, the second protrusion surface of the second protrusion 34 away from the substrate 10, and the first recess 35, which causes the carrier function layer to form a discontinuous pattern structure on the surface of the pixel defining layer 30 on the side away from the substrate 10.

In other embodiments of the present invention, the separation layer may also be a film layer structure covering a portion of the first convex surface, a portion of the second convex surface, and a portion of the first concave portion. That is, the discrete pattern structure is formed by forming the separation layer on the side of the pixel defining region of the pixel defining layer 30 away from the substrate.

As shown in fig. 3A to 3H, the preparation process of the display substrate 100 of the present invention is as follows:

firstly, providing a full-process backboard, wherein the full-process backboard comprises a substrate 10 and a transistor array layer 20, and an unpatterned pixel definition layer 30' is formed on the surface of one side, away from the substrate 10, of the transistor array layer 20;

secondly, coating a photoresist layer 40 on the surface of the unpatterned pixel definition layer 30' far away from the transistor array 20; providing a first mask 50, patterning the unpatterned pixel definition layer 30' to obtain a pixel region 31 and a pixel definition region 32;

then, providing a second photomask 60, patterning the side surface of the pixel defining region 32 away from the substrate 10 to obtain a first protrusion 33 and a second protrusion 34 which are spaced from each other, wherein a first concave portion 35 is formed between the first protrusion 33 and the second protrusion 34, and the depth D1 of the first concave portion 35 is 0.1 μm to 0.5 μm;

finally, preparing a separation layer solution 70, inverting the substrate 10, infiltrating the pixel defining region 32 into the separation layer solution 70, and controlling the distance D2 between the first protrusion surface of the first protrusion 33 and the second protrusion surface of the second protrusion 34 to be less than or equal to 0.1-1 μm below the liquid level of the separation layer solution 70; the substrate 10 is inverted, the functional layer is easily formed, and the separation layer solution 70 is vacuum-dried to form the separation layer 71. The separation layer 71 covers the first protrusion 33, the first recess 35, and the first protrusion 35. Preferably, the first convex surface is a side surface of the first protrusion 33 away from the substrate 10, and the second convex surface is a side surface of the second protrusion 34 away from the substrate 10.

The process of vacuum drying to form the separation layer 71 generally includes: transferring the substrate 10 into an equipment cavity with temperature control and vacuum control, controlling the temperature in the equipment cavity to be 50-200 ℃, and controlling the pressure to be 10 DEG C ^-3 ~10 ^-5 pa, the solvent in the separation layer solution 70 is rapidly volatilized by heating and vacuuming, and a separation layer 71 is formed in the pixel defining region 32 of the pixel defining layer 30.

As can be seen from the above process for manufacturing the display substrate 100, in the present invention, the first protrusion 33 and the second protrusion 34 are formed on the surface of the pixel defining layer 30 away from the substrate 10 by a patterning process (dry etching process), and the depth of the first recess 35 between the first protrusion 33 and the second protrusion 34 is only 0.1 μm to 0.5 μm, so that the depth of the first recess 35 is smaller than that of the existing deep groove structure, and the formation is easier. In addition, the separation layer 71 is formed on the sides of the first protrusion 33, the first recess 35 and the second protrusion 34 away from the substrate 10 by using a solution immersion method, so that the method has the advantages of simple process, easy control and high material utilization rate.

For the purpose of simplifying the manufacturing process, the first mask 50 and the second mask 60 may be combined into a mask process in the manufacturing process of the display substrate 100, such as a half-tone (half-tone) photomask mask, that is, the pixel defining region 32 and the first protrusion 33, the first recess 35 and the second protrusion 34 on the side of the pixel defining region 32 away from the substrate 10 are formed simultaneously by one-step etching, wherein two opposite sidewalls of the first recess 35 are the first protrusion 33 and the second protrusion 34 arranged at an interval.

It should be noted that, in the preparation process of the display substrate 100, after the pixel defining region 32 is soaked with the separation layer solution 70 and turned over, the separation layer solution 70 on the portion of the surface of the first protrusion 33 adjacent to the first recess 35 and the separation layer solution 70 on the portion of the surface of the second protrusion 34 adjacent to the first recess 35 respectively flow into the first recess 35, and the separation layer solution 70 on the portion of the surface of the first protrusion 33 adjacent to the pixel region 31 and the separation layer solution 70 on the portion of the surface of the second protrusion 34 adjacent to the pixel region 31 respectively flow toward the pixel region 31, so that when a light emitting layer is formed in the pixel region 31 by ink jet printing, the light emitting layer cannot be well filled in the pixel region 31.

Further, the present invention also overcomes the problem that the above-mentioned separation layer solution 70 flows from the first projection surface of the first projection 33 and the second projection surface of the second projection 34 toward the pixel region 31 by improving the projection structure of the pixel defining region 32 of the above-mentioned display substrate 100 on the side away from the substrate 10.

As shown in fig. 4A and 4B, in another embodiment of the present invention, a display substrate 200 is provided, the display substrate 200 includes a substrate 10, a transistor array layer 20, and a pixel defining layer 210 disposed from bottom to top, the pixel defining layer 210 includes pixel regions 201 and pixel defining regions 202, a pixel defining region 202 is disposed between any adjacent pixel regions 201, a side of the pixel defining region 202 away from the substrate 10 includes first protrusions 203 and second protrusions 204 disposed at intervals, a first concave portion 205 is disposed between the first protrusions 203 and the second protrusions 204 disposed at intervals, at least one third protrusion 206 is disposed in the first concave portion 205, wherein a third protrusion surface of each third protrusion 206 away from the substrate 10 is higher than a first protrusion surface of the first protrusion 203 away from the substrate 10 and a second protrusion surface of the second protrusion 204 away from the substrate 10. Preferably, the first convex surface is a side surface of the first protrusion 203 away from the substrate 10, and the second convex surface is a side surface of the second protrusion 204 away from the substrate 10; the third convex surface is a side surface of the third protrusion 206 away from the substrate 10.

Preferably, the height H2 of each third bump 206 is greater than the height H1 of the first bump 203 (or the height H1 of the second bump 204), and the difference between H2 and H1 is greater than or equal to 0.1 μm to 1 μm. The height H2 of each third protrusion 206 is the maximum vertical distance from the third protrusion surface of the third protrusion 206 away from the substrate 10 to the bottom of the first recess 205; the height H1 of the first protrusion 203 (or the second protrusion 204) refers to the maximum perpendicular distance from the first protrusion face (or the second protrusion face) of the first protrusion 203 (or the second protrusion 204) away from the substrate 10 to the bottom of the first recess 205.

When the height difference between the third protrusions 206 and the first protrusions 203 (or the second protrusions 204) is between 0.1 μm and 1 μm, the display substrate 200 is inverted and immersed in the separation layer material solution, the depth of the third protrusions 206 immersed below the liquid surface of the separation layer solution is controlled to be 0.1 μm to 1 μm, and at this time, the first protrusions 203 and the second protrusions 204 do not contact the separation layer solution, respectively.

After the immersion process is completed and the display substrate 200 is turned over, the separation layer solution flows along the third protrusion surface of the third protrusion 206 toward the first recess 205, and the separation layer solution flows into the first recess 205 and is blocked by the first protrusion 203 and the second protrusion 204, and does not flow toward the pixel region 201, so that the problem that the light emitting layer is abnormally filled in the open hole due to the flow of the separation layer solution toward the pixel region is solved.

Finally, the separation layer solution covered in the third projections 206 and the first recesses 205 is vacuum-dried to form a separation layer 271.

In the present embodiment, the number of the at least one third protrusion 206 in the first recess 205 may be one or more. When the first recess 205 is a zigzag groove structure disposed around the pixel region 201, the plurality of third protrusions 206 may be arranged in a row along a direction parallel to the first and

second protrusions

203 and 204.

In the display substrate 200, the pixel region 201 and the pixel defining region 202 in the pixel definition 210 are obtained through a first patterning process, the third protrusion 206, the first recess 205, the first protrusion 203 and the second protrusion 204 are obtained through a second patterning process, and the third patterning process is used for supporting the third protrusion, wherein the second patterning process is, for example, a dry etching process.

In other embodiments of the present invention, a third protrusion and a first recess are obtained by a second patterning process, and then the sidewalls on both sides of the first recess are etched by the third patterning process to form a corresponding first protrusion and a corresponding second protrusion. The third patterning process is, for example, a dry etching process.

As shown in fig. 5A and 5B, in a further embodiment of the invention, a display substrate 300 is provided, the display substrate 300 includes a substrate 10, a transistor array layer 20, and a pixel definition layer 310 disposed from bottom to top, the pixel definition layer 310 includes a pixel region 301 and a pixel definition region 302, the pixel definition region 302 is disposed between any adjacent pixel regions 301, a surface of the pixel definition region 302 on a side away from the substrate 10 includes a first protrusion 303, a second protrusion 304, a third protrusion 306, and a fourth protrusion 307, that is, the third protrusion 306 and the fourth protrusion 307 are disposed in a first recess 305 between the first protrusion 303 and the second protrusion 304 disposed at an interval, and the third protrusion 306 and the fourth protrusion 307 include a second recess 308 therebetween.

Preferably, the difference between the height H3 of the third bump 306 (or the fourth bump 307) and the height H4 of the first bump 303 (or the second bump 304) is 0.1 μm to 1 μm. In the present embodiment, the height of the third protrusion 306 is the same as the height of the fourth protrusion 307; the height of the first protrusion 303 is the same as that of the second protrusion 304, but not limited thereto. In other embodiments of the present invention, the height of the third protrusion is different from the height of the fourth protrusion; the height of the first protrusion is different from the height of the second protrusion.

In the present embodiment, the height H3 of the third protrusion 306 (or the fourth protrusion 307) refers to the maximum vertical distance from the third protrusion surface (or the fourth protrusion surface) of the third protrusion 306 (or the fourth protrusion 307) away from the substrate 10 to the bottom of the first recess 305, and the height H4 of the first protrusion 303 (or the second protrusion 304) refers to the maximum vertical distance from the first protrusion surface (or the second protrusion surface) of the first protrusion 303 (or the second protrusion 304) away from the substrate 10 to the bottom of the first recess 305.

When the difference value between the height H3 of the third bulges 306 (or the fourth bulges 307) and the height H4 of the first bulges 303 (or the second bulges 304) is between 0.1 mu m and 1 mu m, the display substrate 300 is inverted and immersed in the separation layer solution, the depth of the third bulges 306 (or the fourth bulges 307) immersed under the liquid surface of the separation layer solution is controlled to be between 0.1 mu m and 1 mu m, and at the moment, the first bulge surfaces of the first bulges 303 far away from the substrate 10 and the second bulge surfaces of the second bulges 304 far away from the substrate 10 are not contacted with the separation layer solution.

After the immersion process is completed and the display substrate 300 is turned over, the separation layer solution flows toward the first concave portion 305 and the second concave portion 308 along the third convex surface of the third protrusion 306 and the fourth convex surface of the fourth protrusion 307, and the separation layer solution is blocked by the first protrusion 303 and the second protrusion 304 and does not flow toward the pixel region 301, thereby overcoming the problem that the above-mentioned separation layer solution flows toward the pixel region, resulting in abnormal filling of the light emitting layer in the pixel region.

Finally, the separation layer solution covered in the third projection 306, the fourth projection 307, the first concave portion 305, and the second concave portion 308 is vacuum-dried to form a separation layer 371.

In addition, in the present embodiment, the first concave portion 305 and the second concave portion 308 are respectively provided around the pixel region 301, wherein the second concave portion 308 is located inside the first concave portion 305.

In the preparation process of the display substrate 300, the pixel region 301 and the pixel defining region 302 in the pixel defining layer 310 are obtained by a first patterning process, and the first recess 305, the third protrusion 306, the third protrusion 307 and the second recess 308 are obtained by a second patterning process; by patterning the support for the third time, the sidewall outside the first recess 305 is etched, forming the first protrusion 303 and the second protrusion 304.

The present invention also provides a method for manufacturing a display substrate, which is used to manufacture the

display panels

100, 200, and 300.

The preparation method of the display substrate provided by the invention comprises the following steps,

s1, providing a back plate comprising the substrate 10 and the unpatterned pixel defining layer 30 ', and coating a photoresist layer 40 on a surface of the unpatterned pixel defining layer 30' away from the substrate; providing a first mask 50, patterning the pixel defining layer, and forming a plurality of pixel regions 31 and a plurality of pixel defining regions 32, wherein the pixel regions 31 are open holes, and each pixel defining region 32 is disposed between any adjacent pixel regions 31;

s2, providing a separation layer solution 70, and infiltrating the pixel definition areas 32 into the separation layer solution 70, wherein the depth of the pixel definition areas 32 immersed under the liquid level of the separation layer solution 70 is less than or equal to 0.1-1 μm;

s3, turning over the display substrate in S2, vacuum-drying the separation layer solution 70, and forming a separation layer 71 on a surface of the pixel defining region 32 on a side away from the substrate; and

s4, forming a carrier function layer on the surface of the pixel defining layer 30 on the side away from the substrate 10;

the separation layer 71 causes the carrier function layer to form a discontinuous pattern structure on the surfaces of the pixel defining region 32 and the pixel region 31 on the side away from the substrate 10.

When the above-described manufacturing method is used to manufacture the display substrate 100 as shown in fig. 1,

s1 further includes: s11, patterning one side of the pixel defining area 32, which is far away from the substrate 10, to form a first protrusion 33 and a second protrusion 34 which are arranged at intervals, wherein a first concave 35 is included between the first protrusion 33 and the second protrusion 34;

s2 further includes: s21, immersing the first bulges and the second bulges into the separating layer solution, wherein the depth of the first bulges and the second bulges immersed under the liquid level of the separating layer solution is less than or equal to 0.1-1 μm;

when the above-described manufacturing method is used to manufacture the display substrate 200 as shown in fig. 4B,

s1 further includes: s12, patterning the pixel defining area 202 to form a first protrusion 203, a second protrusion 204 and at least one third protrusion 206 which are arranged at intervals, wherein the third protrusion surface of each third protrusion 206 far away from the substrate 10 is higher than the first protrusion surface of the first protrusion 203 far away from the substrate 10 and the second protrusion surface of the second protrusion 204 far away from the substrate 10;

s2 further includes: s22, immersing the third protrusion 206 into the separation layer solution 70, wherein the depth of the third protrusion 206 immersed under the liquid surface of the separation layer solution 70 is less than or equal to 0.1-1 μm.

In this embodiment, a first recess 205 is provided between the first protrusion 203 and the second protrusion 204, and at least one third protrusion 206 is disposed in the first recess 205. Preferably, the first recess 205 is a groove structure surrounding the pixel region 201.

When the above-described manufacturing method is used to manufacture the display substrate 300 as shown in fig. 5B,

s1 further includes: s13, patterning the pixel defining region 302 to form a first bump 303, a second bump 304, a third bump 306 and a fourth bump 307 which are arranged at intervals, wherein a third bump surface (or a fourth bump surface) of the third bump 306 (or the fourth bump 307) far away from the substrate 10 is higher than a first bump surface of the first bump 203 far away from the substrate 10 and a second bump surface of the second bump 204 far away from the substrate 10;

s2 further includes: s23, immersing the third protrusion 306 (or the fourth protrusion 307) into the separation layer solution 70, wherein the depth of the third protrusion 306 (or the fourth protrusion 307) immersed under the liquid surface of the separation layer solution 70 is less than or equal to 0.1-1 μm.

In this embodiment, the first protrusion 303 and the second protrusion 304 have a first recess 305 therebetween, and the third protrusion 306 and the fourth protrusion 307 have a second recess 308 therebetween. Preferably, the first concave portion 305 and the second concave portion 308 are groove structures surrounding the pixel region 201, respectively, wherein the second concave portion 308 is located inside the first concave portion 305, that is, the second concave portion 308 is closer to the pixel region 301.

In summary, the present invention provides a display substrate and a method for manufacturing the same, wherein a separation layer is formed on a surface of a pixel defining layer of the display substrate, the surface being away from the substrate, and the separation layer enables a discontinuous carrier function layer to be formed on a pixel defining region and a pixel region of the pixel defining layer, so as to disconnect a lateral charge transmission in the carrier function layer between adjacent pixels, thereby overcoming a lateral crosstalk problem when the pixels are lit. Further, the structure of the protrusion of the pixel defining region is optimized, so that the separation layer is ensured not to flow into the pixel region, and the problem of abnormal filling of the light emitting layer in the pixel region due to the existence of the separation layer in the pixel region is avoided.

It should be understood that although the present description refers to embodiments, not every embodiment contains only a single technical solution, and such description is for clarity only, and those skilled in the art should make the description as a whole, and the technical solutions in the embodiments can also be combined appropriately to form other embodiments understood by those skilled in the art.

The above-listed detailed description is merely a detailed description of possible embodiments of the present invention, and it is not intended to limit the scope of the invention, and equivalent embodiments or modifications made without departing from the technical spirit of the present invention are intended to be included within the scope of the present invention.

Claims

1. A display substrate comprises a substrate and a pixel definition layer arranged on one side of the substrate, wherein the pixel definition layer comprises a pixel definition area and a pixel area, and the display substrate is characterized by further comprising:

a separation layer formed on a side of the pixel defining region away from the substrate; and

the carrier function layer is formed on the surface of one side, away from the pixel defining layer, of the separation layer;

wherein the separation layer causes the carrier function layer to form a discontinuous pattern structure on the pixel defining region and a surface of one side of the pixel region away from the substrate; and further, the transverse transmission of carriers in the carrier functional layer between adjacent pixels is cut off.

2. The display substrate according to claim 1, wherein a material of the separation layer is selected from a fluorine-containing substituent having an alkyl chain of 3 or more carbon atoms, a fluorine-containing substituent having a silane chain of 3 or more silicon atoms, and a mixture of the two.

3. The display substrate according to claim 1, wherein a surface of the pixel defining region on a side away from the substrate comprises a first protrusion and a second protrusion, the first protrusion and the second protrusion are spaced apart from each other, and a first recess is formed between the first protrusion and the second protrusion.

4. The display substrate according to claim 3, wherein a depth of the first concave portion in a direction perpendicular to the display substrate is 0.1 μm to 0.5 μm.

5. The display substrate according to claim 3, wherein a cross-sectional shape of the first recess in a direction perpendicular to the display substrate includes at least one of a U-shape, a rectangular shape, a V-shape, a regular trapezoid, and an inverted trapezoid.

6. The display substrate according to claim 3, wherein the first protrusion and the second protrusion are respectively disposed around the pixel region, and the first recess is a groove disposed around the pixel region.

7. The display substrate according to claim 3, wherein a side surface of the pixel defining area away from the substrate further comprises at least one third protrusion disposed in the first recess, wherein a third protrusion surface of each third protrusion away from the substrate is higher than a first protrusion surface of the first protrusion away from the substrate, and the third protrusion surface is higher than a second protrusion surface of the second protrusion away from the substrate.

8. A preparation method of a display substrate, wherein the display substrate comprises a substrate and a pixel definition layer arranged on one side of the substrate, is characterized by comprising the following steps:

s2, providing a separation layer solution, and immersing the pixel definition region into the separation layer solution, wherein the depth of the pixel definition region immersed under the liquid level of the separation layer solution is 0.1-1 μm; and

9. The method of manufacturing a display substrate according to claim 8,

the S1 further includes:

s11: patterning the pixel defining area to form a first protrusion and a second protrusion which are arranged at intervals;

the S2 further includes:

s21: immersing the first bulges and the second bulges into the separating layer solution, wherein the depth of the first bulges and the second bulges immersed under the liquid surface of the separating layer solution is 0.1-1 mu m;

wherein the first protrusion and the second protrusion include a first recess therebetween.

10. The method of manufacturing a display substrate according to claim 8,

the S1 further includes:

s12: patterning the pixel defining area to form a first protrusion, a second protrusion and at least one third protrusion which are arranged at intervals, wherein the third protrusion surface of each third protrusion, which is far away from the substrate, is higher than the first protrusion surface of the first protrusion, which is far away from the substrate, and the second protrusion surface of the second protrusion, which is far away from the substrate;

the S2 further includes:

s22: and immersing the third protrusion into the separation layer solution, wherein the depth of the third protrusion immersed below the liquid level of the separation layer solution is 0.1-1 μm.