CN109004106A - Display base plate and preparation method thereof, display device - Google Patents

Abstract

The invention provides a display substrate, a preparation method thereof, and a display device, which belong to the field of display technology. The display substrate of the present invention includes an isolation column located on a base, and the isolation column includes: a first isolation layer and a second isolation layer; wherein, the first isolation layer is located on a side of the second isolation layer away from the base; the second isolation layer and the second isolation layer The first isolation layer has a bottom surface close to the base and a top surface away from the base respectively; wherein, the top surface of the first isolation layer covers the bottom surface of the first isolation layer on the base orthographic projection of the base, and the top surface of the second isolation layer The orthographic projection of the surface on the substrate covers the orthographic projection of the bottom surface of the second isolation layer on the substrate, the orthographic projection of the bottom surface of the second isolation layer on the substrate covers the orthographic projection of the top surface of the first isolation layer on the substrate, and the orthographic projection of the top surface of the second isolation layer The area of the bottom surface is larger than the area of the top surface of the first isolation layer.

Description

Display substrate, manufacturing method thereof, and display device

technical field

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

Background technique

As shown in Figure 1, in the passive matrix OLED display substrate, in order to achieve the high resolution and colorization of the passive matrix OLED, and better solve the problems of low resolution of the cathode template and low device yield, an inverted trapezoidal cathode is proposed. The design of the spacer allows the natural breakage of the cathode layer by using the spacer to form multiple cathode patterns during the manufacturing process of the OLED device, thereby improving the product yield.

Among them, in order to give full play to the partition function of the inverted trapezoidal isolation column, there is a large gap between the top surface and the bottom surface of the isolation column. Due to the limited chamfer angle of the inverted trapezoidal isolation column formed by existing materials, it can only pass through the isolation column. The high design enhances its isolation function, which will limit the thinning of the display substrate.

Contents of the invention

The present invention aims to solve at least one of the technical problems in the prior art, and provides a display substrate capable of reducing the thickness of the display substrate and improving the isolation effect.

The technical solution adopted to solve the technical problem of the present invention is a display substrate, including an isolation column on the base, and the isolation column includes: a first isolation layer and a second isolation layer;

Wherein, the first isolation layer is located on the side of the second isolation layer away from the substrate;

The second isolation layer and the first isolation layer respectively have a bottom surface close to the base and a top surface far away from the base; wherein, the top surface of the first isolation layer covers all The orthographic projection of the bottom surface of the first isolation layer on the substrate, the orthographic projection of the top surface of the second isolation layer on the substrate covers the orthographic projection of the bottom surface of the second isolation layer on the substrate, the The orthographic projection of the bottom surface of the second isolation layer on the base covers the orthographic projection of the top surface of the first isolation layer on the substrate, and the area of the bottom surface of the second isolation layer is larger than that of the first isolation layer. The area of the top surface.

Preferably, the first isolation layer is made of the same material as the second isolation layer.

Further preferably, materials of the first isolation layer and the second isolation layer both include organic photoresist.

Preferably, the materials of the first isolation layer and the second isolation layer are different.

Further preferably, the material of the first isolation layer is a first negative photoresist; the material of the second isolation layer is a second negative photoresist; the light sensitivity of the first negative photoresist greater than the photosensitivity of the second negative-tone photoresist;

Or, the material of the first isolation layer is a first positive photoresist; the material of the second isolation layer is a second positive photoresist; the light sensitivity of the first positive photoresist is less than the Describe the photosensitivity of the second positive photoresist.

Preferably, the display substrate is an OLED display substrate.

The technical solution adopted to solve the technical problem of the present invention is a method for preparing a display substrate, comprising:

sequentially forming the patterns of the first isolation layer and the second isolation layer on the substrate through a patterning process;

Wherein, the second isolation layer and the first isolation layer respectively have a bottom surface close to the base and a top surface away from the base; wherein, the top surface of the first isolation layer covers the first isolation layer the bottom surface of the second isolation layer, the top surface of the second isolation layer covers the bottom surface of the second isolation layer, the bottom surface of the second isolation layer covers the top surface of the first isolation layer, and the bottom surface of the second isolation layer The area is greater than the area of the top surface of the first isolation layer.

Preferably, the step of sequentially forming the patterns of the first isolation layer and the second isolation layer on the substrate through a patterning process specifically includes:

Forming a film layer of a first isolation layer on the substrate, and forming a pattern of the first isolation layer on the substrate through a patterning process;

A second isolation layer film layer is formed on the substrate on which the first isolation layer is formed, and the second isolation layer is formed through a patterning process.

Preferably, the step of sequentially forming the patterns of the first isolation layer and the second isolation layer on the substrate through a patterning process specifically includes:

sequentially forming a first isolation layer film layer and a second isolation layer film layer on the substrate, and forming a pattern including the first isolation layer and the second isolation layer through a patterning process;

Wherein, the material of the first isolation layer is a first negative photoresist; the material of the second isolation layer is a second negative photoresist; the light sensitivity of the first negative photoresist is greater than the Describe the photosensitivity of the second negative photoresist;

Or, the material of the first isolation layer is a first positive photoresist; the material of the second isolation layer is a second positive photoresist; the light sensitivity of the first positive photoresist is less than the Describe the photosensitivity of the second positive photoresist.

Preferably, the display substrate is an OLED display substrate;

After the step of sequentially forming the patterns of the first isolation layer and the second isolation layer on the substrate through a patterning process, it also includes: forming a pattern of a cathode layer on the substrate through an evaporation process, and the cathode layer is formed on the second isolation layer. The edge position of the layer is naturally broken and divided into multiple cathode patterns.

The technical solution adopted to solve the technical problem of the present invention is a display device, including: any one of the above-mentioned display substrates.

Description of drawings

FIG. 1 is a schematic structural diagram of an existing display substrate;

Figure 2 is a schematic structural view of a display substrate according to an embodiment of the present invention

FIG. 3 is a schematic diagram of an implementation manner of forming spacers in a method for preparing a display substrate according to an embodiment of the present invention;

4 is a schematic diagram of another embodiment of forming spacers in the method for preparing a display substrate according to an embodiment of the present invention;

5 is a schematic diagram of forming a light-emitting layer and a cathode in a method for preparing a display substrate according to an embodiment of the present invention;

Wherein the reference signs are: 1. base; 2. anode pattern; 3. isolation post; 31. first isolation layer; 32. second isolation layer; 33. first isolation layer film; 34. second isolation layer film layer; 4, light-emitting layer; 5, cathode pattern.

Detailed ways

In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Example 1:

As shown in Figure 2, this embodiment provides a display substrate, which is particularly suitable for OLED (Organic Light-Emitting Diode; organic electroluminescent diode) display substrate, specifically, it can be an active OLED display substrate, or it can be a passive OLED Displays the substrate. Hereinafter, the present embodiment will be specifically described by taking an OLED display substrate as an example. The display substrate in this embodiment includes a substrate 1, on which a plurality of rows of anode patterns 2 are arranged, and a plurality of rows of spacer columns 3 are arranged above the layer where the anode pattern 2 is located, and a light-emitting layer and a cathode are sequentially arranged above the layer where the spacer column 3 is located. layer, and the luminescent layer and the cathode layer are broken at the edge of the spacer 3, forming a multi-column cathode pattern 5 spaced apart from the spacer 3, and each overlapping position of the multi-row anode pattern 2 and the multi-column cathode pattern 5 defines multiple OLED unit, the light emitting layer 4 is located between the cathode 5 and the anode pattern 2.

In particular, the isolation column 3 in this embodiment includes: a first isolation layer 31 and a second isolation layer 32 . Wherein, the first isolation layer 31 is located on the side of the second isolation layer 32 away from the base 1; the second isolation layer 32 and the first isolation layer 31 respectively have a bottom surface close to the base 1 and a top surface away from the base 1; wherein, the first The orthographic projection of the top surface of the isolation layer 31 on the substrate 1 covers the orthographic projection of the bottom surface of the first isolation layer 31 on the substrate 1, and the top surface of the second isolation layer 32 covers the bottom surface of the second isolation layer 32 on the orthographic projection of the substrate 1. Orthographic projection of the substrate 1, the orthographic projection of the bottom surface of the second isolation layer 32 on the substrate 1 covers the orthographic projection of the top surface of the first isolation layer 31 on the substrate 1, and the area of the bottom surface of the second isolation layer 32 is larger than that of the first isolation layer The area of the top surface of 31.

As shown in FIG. 2, the isolation column 3 in this embodiment includes a first isolation layer 31 and a second isolation layer 32, the first isolation layer 31 is closer to the substrate 1 than the second isolation layer 32, and the second isolation layer 32 covers the first isolation layer 32. An isolation layer 31, and the area of the second isolation layer 32 is larger than the area of the first isolation layer 31, that is, the junction of the bottom surface of the second isolation layer 32 and the top surface of the first isolation layer 31 forms a fault structure, and at the same isolation width (the width of the top surface of the isolation column 3), the width of the bottom surface of the isolation column 3 can be smaller. Wherein, the specific size (for example, area difference) of the first isolation layer 31 and the second isolation layer 32 can be specifically set according to the actual partition effect requirements, and is not limited here.

When the cathode pattern 5 is prepared on the substrate 1 formed with the isolation column 3, the cathode layer can be better separated to form a plurality of cathode patterns 5, and the above-mentioned fault structure can be used to slow down the climbing of the edge of the cathode pattern 5 to the isolation column. 3, thereby improving the yield of the cathode pattern 5 and improving the display effect of the display substrate. At the same time, the isolation column 3 with a single-layer inverted trapezoidal structure in the prior art not only has special requirements for the material of the isolation column 3 , but also needs to meet a certain height to realize the inverted trapezoidal structure, which will undoubtedly increase the difficulty of preparing the isolation column 3 . In this embodiment, the isolation column 3 is formed by two layers of isolation layers, and the shape of the isolation column 3 is no longer limited to an inverted trapezoid, as long as the upper part is larger and the lower part is small. For example, the isolation column 3 in this embodiment can be " T " shape, the height of each spacer layer and the whole spacer column 3 has no restriction at this moment, that is to say the height of the spacer column 3 in the present embodiment can be lower with respect to the spacer column 3 in the prior art, thereby helps In order to show the lightness and thinning of the substrate, and can significantly reduce the difficulty of manufacturing the spacer column 3 . Of course, the height of the isolation column 3 is controllable, and it can be specifically set according to actual needs. Further, since the isolation column 3 of this embodiment can make the display substrate lighter and thinner while having a good partition effect, it is not necessary to integrate the inverted trapezoidal isolation column 3 in the prior art, in order to increase the size of the isolation column 3 The chamfering and research and development of new materials, which can save research and development costs.

As an embodiment of this embodiment, preferably, the materials of the first isolation layer 31 and the second isolation layer 32 are different. Specifically, the material of the first isolation layer 31 is a first negative photoresist; the material of the second isolation layer 32 is a second negative photoresist; the light sensitivity of the first negative photoresist is greater than that of the second negative photoresist. The light sensitivity of the photoresist. Or, the material of the first isolation layer 31 is a first positive photoresist; the material of the second isolation layer 32 is a second positive photoresist; the photosensitivity of the first positive photoresist is less than that of the second positive photoresist. The light sensitivity of the resist. The advantage of designing such a structure is that when preparing the isolation column 3, two layers of photoresist film layers can be coated to utilize the different light sensitivities of the two materials, and a double layer can be formed through a single patterning process. The structural isolation column 3 is used to simplify the preparation process of the display substrate.

As another embodiment of this embodiment, the first isolation layer 31 and the second isolation layer 32 are made of the same material. Specifically, both materials include organic photoresist, such as positive photoresist and negative photoresist. When the first isolation layer 31 and the second isolation layer 32 are made of the same material, they should be formed step by step, first forming the lower first isolation layer 31 , and then forming the upper second isolation layer 32 .

It can be understood that the isolation columns 3 in the display substrate in this embodiment are not limited to the above-mentioned first isolation layer 31 and second isolation layer 32, but may also include multiple isolation layers such as the third isolation layer and the fourth isolation layer. structure, in which, as long as the projection of the isolation layer far away from the base 1 on the base 1 of the isolation column 3 covers the projection on the base 1 of the isolation layer close to the base 1, and the area is larger, so as to achieve a good isolation of the cathode 5 effect.

It should be noted here that when the display substrate is a passive OLED display substrate, the light-emitting layer and the cathode group are sequentially formed by evaporation process after the above-mentioned spacers are formed. Since the above-mentioned spacers 3 have a good partition effect, the passive The finished product yield of the source OLED device. At the same time, when the passive OLED display substrate is a bottom emission display substrate, in the case of the same resolution (same width of the top surface of the spacer column 3, same pixel size), since the bottom surface of the spacer column 3 in this embodiment can be smaller, so that the aperture ratio of the display substrate can be increased.

When the display substrate is an active OLED display substrate, a plurality of gate lines and a plurality of data lines on the substrate, and the intersecting arrangement of the gate lines and data lines define a plurality of pixel units; each pixel unit includes a pixel driving structure and OLED device; the OLED device includes an anode pattern, a light-emitting layer, and a cathode arranged on the substrate in sequence; the anode pattern is connected to the drain of the thin film transistor in the pixel driving structure; a pixel defining layer is formed above the anode pattern, and the pixel defining layer At least part of the retaining wall is provided with the above-mentioned isolation columns, and the luminescent layer and the cathode are sequentially formed by evaporation process after the isolation columns are formed.

In the display substrate provided in this embodiment, the integrated inverted trapezoidal spacer in the prior art is replaced by a double-layer spacer structure with a large top and a small bottom, which can better play a role in the preparation of organic light-emitting layers, cathodes and other structures. In addition, the height of the isolation columns in this embodiment can be lower than that of the isolation columns in the prior art, thereby helping to reduce the thickness of the display substrate.

Example 2:

As shown in FIGS. 3 to 5 , this embodiment provides a method for preparing a display substrate, which can be used to prepare the display substrate provided in Embodiment 1. Wherein, the display substrate may be an OLED display substrate, such as a passive OLED display substrate, an active OLED display substrate, and the following takes the passive OLED display substrate as an example for specific description.

The basic preparation method shown in this embodiment specifically includes the following steps:

S1. Form a plurality of rows of anode patterns 2 on the substrate 1 through a patterning process.

Wherein, the substrate is supported by transparent materials such as glass, and has been pre-cleaned. In this step, by using a half tone mask (Half Tone Mask, referred to as HTM) or a gray tone mask (Gray Tone Mask, referred to as GTM), through the patterning process (film formation, exposure, development, wet etching or dry method) Etching) formed anode pattern 2.

S2 , forming a plurality of columns of isolation columns 3 on the substrate 1 formed with the anode pattern 2 through a patterning process.

As shown in FIGS. 3 and 4 , wherein the spacer column 3 includes a first spacer layer 31 and a second spacer layer 32 , the second spacer layer 32 and the first spacer layer 31 have a bottom surface close to the base 1 and a top away from the base 1 respectively. Surface; Wherein, the top surface of the first isolation layer 31 covers the bottom surface of the first isolation layer 31, the top surface of the second isolation layer 32 covers the bottom surface of the second isolation layer 32, and the bottom surface of the second isolation layer 32 covers the first isolation layer 31, and the area of the bottom surface of the second isolation layer 32 is larger than the area of the top surface of the first isolation layer 31.

Specifically, the isolation column 3 in this embodiment (that is, step S2 ) can be formed through the following two implementation methods.

As shown in Figure 3, as one of the implementation manners, step S2 specifically includes the following steps:

S21 , forming a first isolation layer on the substrate 1 , and forming a pattern of the first isolation layer 31 on the substrate 1 through a patterning process.

Specifically, a first isolation layer film layer (not shown in FIG. 3 ) can be formed on the substrate 1 by spin coating, etc., and multiple columns of the first isolation layer 31 can be formed on the substrate 1 through patterning processes such as exposure and development. graphics. Wherein, the material of the first isolation layer 31 may be photoresist, specifically positive photoresist or negative photoresist.

S22 , forming a second isolation layer (not shown in FIG. 3 ) on the substrate 1 formed with the first isolation layer 31 , and forming the second isolation layer 32 through a patterning process.

Step S22 is similar to step S21 and will not be described in detail here. It should be noted here that, wherein, the area of the bottom surface of the second isolation layer 32 is larger than the area of the top surface of the first isolation layer 31, so as to realize the isolation column 3 formed by the first isolation layer 31 and the second isolation layer 32. Good masking effect. Wherein, the materials of the first isolation layer 31 and the second isolation layer 32 in step S21 and step S22 may be the same or different.

As shown in Figure 4, as another implementation manner, step S2 specifically includes the following steps:

A first isolation layer film layer 33 and a second isolation layer film layer 34 are sequentially formed on the substrate 1, and a pattern including the first isolation layer 31 and the second isolation layer 32 is formed through a patterning process.

Specifically, the first isolation layer film layer 33 and the second isolation layer film layer 34 can be formed on the substrate 1 by spin coating, etc., and multiple columns including the first isolation layer layer are formed on the substrate 1 at a time through patterning processes such as exposure and development. Figures of the isolation layer 31 and the second isolation layer 32.

Wherein, the material of the first isolation layer 31 (that is, the first isolation layer film layer 33) is the first negative photoresist; the material of the second isolation layer 32 (that is, the second isolation layer film layer 34) is the second Negative photoresist; the photosensitivity of the first negative photoresist is greater than the photosensitivity of the second negative photoresist; or, the material of the first isolation layer 31 is the first positive photoresist; the second isolation layer The material at 32 is the second positive photoresist; the light sensitivity of the first positive photoresist is smaller than the light sensitivity of the second positive photoresist. That is, through the arrangement of the above-mentioned two kinds of material film layers with different light sensitivities, after exposure and development, the required structure of spacer columns 3 with a large top and a small bottom can be formed, so as to realize the separation between the first spacer layer 31 and the second spacer layer. 32 constitutes a good shielding effect of the isolation column 3. At the same time, forming the isolation column 3 with a double-layer structure through a single patterning process can simplify the manufacturing process of the display substrate.

S3, forming multiple rows of organic light-emitting layers 4 and cathode patterns 5 on the substrate 1 through an evaporation process.

As shown in FIG. 5 , in this step, the organic light-emitting layer 4 and the cathode pattern 5 can be formed by a vacuum evaporation process. Specifically, the raw material to be formed into a thin film can be formed in a heated evaporation container in a vacuum environment, and its atoms or molecules are vaporized and escaped from the surface to form a vapor flow, which is incident on the surface of the substrate 1 to form a solid thin film. Wherein, the spacer column 3 has been formed in the step S2. Since the spacer column 3 is a double-layer structure with a large upper part and a smaller lower part, it can play a good role in separating the organic light-emitting layer material and the cathode layer material in the step S3. The edge positions of the two isolation layers 32 are naturally disconnected and divided into multiple rows of strip-shaped organic layers and cathode patterns 5 . Wherein, multiple rows of anode patterns 2 and multiple columns of cathode patterns 5 overlap to define a plurality of OLED units, and the light emitting layer 4 is located between the cathodes 5 and the anode patterns 2, thereby realizing a pixel array.

It should be noted here that when using the preparation method provided in this embodiment to prepare an active OLED display substrate, the anode pattern 2 should be a whole-layer structure, and a pixel defining layer is formed above the anode pattern 2, and the accommodating portion of the pixel defining layer A bare organic light-emitting material is formed. The isolation column 3 is formed on a part of the retaining wall of the pixel definition layer, and the formation steps can refer to the above-mentioned step S2 for details. When forming the cathode, the cathode layer is naturally broken at the edge of the second isolation layer to form a plurality of block-shaped cathode patterns, and each cathode pattern can correspond to a plurality of rows and/or columns of accommodating parts of the pixel defining layer (that is, a plurality of pixel units).

Example 3:

This embodiment provides a display device, including the display substrate provided in Embodiment 1.

That is to say, the display substrate provided in Embodiment 1 and other structures can be used to form a display device with a display function. Specifically, the display device can be any product or component with a display function such as an organic light emitting diode (OLED) display panel, electronic paper, mobile phone, tablet computer, television, monitor, notebook computer, digital photo frame, and navigator.

It can be understood that, the above embodiments are only exemplary embodiments adopted for illustrating the principle of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims (11)

1. A display substrate, comprising spacer posts positioned on the base, characterized in that, The isolation column includes: a first isolation layer and a second isolation layer; Wherein, the first isolation layer is located on the side of the second isolation layer away from the substrate; The second isolation layer and the first isolation layer respectively have a bottom surface close to the base and a top surface far away from the base; wherein, the top surface of the first isolation layer covers all The orthographic projection of the bottom surface of the first isolation layer on the substrate, the orthographic projection of the top surface of the second isolation layer on the substrate covers the orthographic projection of the bottom surface of the second isolation layer on the substrate, the The orthographic projection of the bottom surface of the second isolation layer on the base covers the orthographic projection of the top surface of the first isolation layer on the substrate, and the area of the bottom surface of the second isolation layer is larger than that of the first isolation layer. The area of the top surface. 2. The display substrate according to claim 1, characterized in that, The first isolation layer is made of the same material as the second isolation layer. 3. The display substrate according to claim 2, characterized in that, Materials of the first isolation layer and the second isolation layer both include organic photoresist. 4. The display substrate according to claim 1, characterized in that, The material of the first isolation layer is different from that of the second isolation layer. 5. The display substrate according to claim 4, characterized in that, The material of the first isolation layer is a first negative photoresist; the material of the second isolation layer is a second negative photoresist; the light sensitivity of the first negative photoresist is greater than that of the first negative photoresist The light sensitivity of the double negative photoresist; Or, the material of the first isolation layer is a first positive photoresist; the material of the second isolation layer is a second positive photoresist; the light sensitivity of the first positive photoresist is less than the Describe the photosensitivity of the second positive photoresist. 6. The display substrate according to claim 1, characterized in that, The display substrate is an OLED display substrate. 7. A method for preparing a display substrate, comprising: sequentially forming the patterns of the first isolation layer and the second isolation layer on the substrate through a patterning process; Wherein, the second isolation layer and the first isolation layer respectively have a bottom surface close to the base and a top surface away from the base; wherein, the top surface of the first isolation layer covers the first isolation layer the bottom surface of the second isolation layer, the top surface of the second isolation layer covers the bottom surface of the second isolation layer, the bottom surface of the second isolation layer covers the top surface of the first isolation layer, and the bottom surface of the second isolation layer The area is greater than the area of the top surface of the first isolation layer. 8. The method for preparing a display substrate according to claim 7, wherein the step of sequentially forming the graphics of the first isolation layer and the second isolation layer on the substrate through a patterning process specifically comprises: Forming a film layer of a first isolation layer on the substrate, and forming a pattern of the first isolation layer on the substrate through a patterning process; A second isolation layer film layer is formed on the substrate on which the first isolation layer is formed, and the second isolation layer is formed through a patterning process. 9. The method for preparing a display substrate according to claim 7, wherein the step of sequentially forming the graphics of the first isolation layer and the second isolation layer on the substrate through a patterning process specifically comprises: sequentially forming a first isolation layer film layer and a second isolation layer film layer on the substrate, and forming a pattern including the first isolation layer and the second isolation layer through a patterning process; Wherein, the material of the first isolation layer is a first negative photoresist; the material of the second isolation layer is a second negative photoresist; the light sensitivity of the first negative photoresist is greater than the Describe the photosensitivity of the second negative photoresist; Or, the material of the first isolation layer is a first positive photoresist; the material of the second isolation layer is a second positive photoresist; the light sensitivity of the first positive photoresist is less than the Describe the photosensitivity of the second positive photoresist. 10. The method for preparing a display substrate according to claim 7, characterized in that, The display substrate is an OLED display substrate; After the step of sequentially forming the patterns of the first isolation layer and the second isolation layer on the substrate through a patterning process, it also includes: forming a pattern of a cathode layer on the substrate through an evaporation process, and the cathode layer is formed on the second isolation layer. The edge position of the layer is naturally broken and divided into multiple cathode patterns. 11. A display device, characterized in that it comprises: The display substrate according to any one of claims 1 to 6.