CN117042510A

CN117042510A - Display panel, preparation method thereof and display device

Info

Publication number: CN117042510A
Application number: CN202310804922.7A
Authority: CN
Inventors: 杨盛际; 单庆山; 陈小川; 黄寅虎; 白枭; 吴斌; 袁涛; 李云龙; 张大成
Original assignee: BOE Technology Group Co Ltd; Yunnan Chuangshijie Optoelectronics Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Yunnan Chuangshijie Optoelectronics Technology Co Ltd
Priority date: 2023-06-30
Filing date: 2023-06-30
Publication date: 2023-11-10

Abstract

A display panel, comprising: a drive back plate; the first electrode layer comprises a plurality of first electrodes which are distributed at intervals; the pixel definition layer is provided with a plurality of pixel openings, and each first electrode is exposed at the pixel opening; a plurality of separation grooves are formed in one side, away from the driving backboard, of the pixel definition layer, and orthographic projection of the separation grooves on the driving backboard is not overlapped with orthographic projection of the first electrode on the driving backboard; the orthographic projection of the light-emitting layer on the driving backboard covers the pixel definition layer and the first electrode layer; the second electrode is positioned on one side of the light-emitting layer, which is far away from the driving backboard, and orthographic projection of the second electrode on the driving backboard covers the light-emitting layer; the auxiliary electrode is positioned on one side of the second electrode, which is far away from the driving backboard, is in contact with the second electrode and is electrically connected with the second electrode, the orthographic projection of the auxiliary electrode on the driving backboard is positioned in the orthographic projection area of the pixel definition layer on the driving backboard, and the orthographic projection of the auxiliary electrode on the driving backboard at least covers the separation groove.

Description

Display panel, preparation method thereof and display device

Technical Field

The embodiment of the disclosure belongs to the technical field of display, and particularly relates to a display panel, a preparation method thereof and a display device.

Background

Silicon-based OLED (Organic Light Emitting Diode) microdisplays possess very excellent display characteristics compared to DLP (Digital Light Porsessor) and LCOS (Liquid Crystal On Silicon) microdisplays. The silicon-based OLED has high brightness, rich colors, low driving voltage, high response speed and low power consumption, and has very excellent user experience; the silicon-based OLED is an all-solid-state device, has good anti-seismic performance and a wide working temperature range (within the range of-40 ℃ to 85 ℃), and is suitable for military and special applications; the self-luminous display device also belongs to a self-luminous device, does not need a backlight source, has a large visual angle range and a thin thickness, is beneficial to reducing the system volume, and is particularly suitable for a near-eye display system.

Disclosure of Invention

The embodiment of the disclosure provides a display panel, a preparation method thereof and a display device.

In a first aspect, an embodiment of the present disclosure provides a display panel, including:

a drive back plate;

the first electrode layer is arranged on one side surface of the driving backboard and comprises a plurality of first electrodes which are distributed at intervals;

the pixel definition layer is positioned on one side of the first electrode layer, which is away from the driving backboard, and is provided with a plurality of pixel openings, and each first electrode is exposed at the pixel opening; a plurality of separation grooves are further formed in one side, away from the driving backboard, of the pixel definition layer, and orthographic projection of the separation grooves on the driving backboard is not overlapped with orthographic projection of the first electrode on the driving backboard;

The light-emitting layer is positioned on one side of the pixel definition layer, which is away from the driving backboard, and the orthographic projection of the light-emitting layer on the driving backboard covers the pixel definition layer and the first electrode layer;

the second electrode is positioned on one side of the light-emitting layer, which is away from the driving backboard, and the orthographic projection of the second electrode on the driving backboard covers the light-emitting layer;

the auxiliary electrode is positioned on one side of the second electrode, which is far away from the driving backboard, is in contact with the second electrode and is electrically connected with the second electrode, the orthographic projection of the auxiliary electrode on the driving backboard is positioned in the orthographic projection area of the pixel definition layer on the driving backboard, and the orthographic projection of the auxiliary electrode on the driving backboard at least covers the separation groove.

In some embodiments, the auxiliary electrode includes a first portion and a second portion, the first portion and the second portion being integrally connected,

the second portion is located on opposite sides of the first portion,

the front projection of the first part on the driving backboard coincides with the front projection of the separation groove on the driving backboard,

the orthographic projection of the second portion on the driving back plate and the orthographic projection of the separation groove on the driving back plate are not overlapped,

The thickness of the first portion is greater than the thickness of the second portion.

In some embodiments, a surface of the first portion facing away from the drive backplate smoothly transitions with a surface of the second portion facing away from the drive backplate.

In some embodiments, a distance between a surface of the first portion facing away from the drive backplate and the drive backplate is greater than or equal to a distance between a surface of the second portion facing away from the drive backplate and the drive backplate.

In some embodiments, a surface of the second electrode facing away from the drive backplate smoothly transitions with a surface of the second portion facing away from the drive backplate.

In some embodiments, a distance between a surface of the second portion facing away from the drive backplate and the drive backplate is greater than or equal to a distance between a surface of the second electrode facing away from the drive backplate and the drive backplate.

In some embodiments, the thickness of the first portion is greater than the thickness of the second electrode,

the thickness of the second portion is less than the thickness of the second electrode.

In some embodiments, the ratio of the first portion thickness to the second electrode thickness ranges from 4:1 to 7:1,

The ratio of the second portion thickness to the second electrode thickness ranges from 1: 3-1: 2.

in some embodiments, an orthographic projection of the second portion on the drive backplate partially overlaps an orthographic projection of the first electrode on the drive backplate.

In some embodiments, an orthographic projection of the second portion on the drive backplate does not overlap with an orthographic projection of the first electrode on the drive backplate.

In some embodiments, the shortest distance between the orthographic projection edge of the auxiliary electrode on the driving back plate and the orthographic projection edge of the pixel opening adjacent thereto on the driving back plate ranges from 0.3 μm to 0.5 μm.

In some embodiments, the pixel defining layer includes a first insulating layer and a second insulating layer,

the first insulating layer and the second insulating layer are stacked away from the driving back plate in sequence,

the separation groove penetrates through the thickness of the second insulating layer, and the first insulating layer is exposed at the separation groove;

the second insulating layer comprises a first sub-layer, a second sub-layer and a third sub-layer, the first sub-layer, the second sub-layer and the third sub-layer are sequentially far away from the driving backboard and are overlapped,

The side surface of the second sub-layer serving as the groove wall of the separation groove is inwards contracted towards the direction close to the pixel opening relative to the side surfaces of the first sub-layer and the third sub-layer serving as the groove wall of the separation groove so as to form a suspension groove between the first sub-layer and the third sub-layer,

the light-emitting layer comprises a plurality of light-emitting sublayers which are sequentially stacked, and at least part of the light-emitting sublayers are disconnected at the suspended grooves.

In some embodiments, the depth of the suspension trench is the thickness of the second sub-layer,

the width of the suspension groove is the distance between the orthographic projection of the side surface of the second sub-layer serving as the groove wall of the separation groove on the driving back plate and the orthographic projection of the side surface of the third sub-layer serving as the groove wall of the separation groove on the driving back plate,

the thickness of the first portion is greater than the depth of the suspension channel,

the thickness of the first portion is greater than the width of the suspension channel.

In some embodiments, the thickness of the first portion is 1-2 times the depth of the suspension groove,

the thickness of the first part is 0.5-1 times of the width of the suspension groove.

In some embodiments, the thickness of the first insulating layer is less than the thickness of the first electrode layer,

The thickness of the first insulating layer is smaller than that of the second insulating layer.

In some embodiments, the sidewalls of the pixel openings are sloping surfaces that diverge in a direction away from the drive backplate,

the slope angle of the slope is not more than 90 degrees.

In some embodiments, the front projection of the auxiliary electrode on the driving back plate surrounds the front projection of the pixel opening on the driving back plate.

In some embodiments, the auxiliary electrode connection is mesh-shaped.

In a second aspect, an embodiment of the present disclosure further provides a display device, including the display panel described above.

In a third aspect, an embodiment of the present disclosure further provides a method for manufacturing a display panel, including:

preparing a driving backboard;

sequentially preparing a first electrode layer, a pixel definition layer, a light-emitting layer and a second electrode on one side of the driving backboard to form a substrate to be plated;

preparing an auxiliary electrode on one side of the second electrode, which is far away from the driving backboard;

the preparing of the auxiliary electrode includes:

forming an auxiliary electrode film layer on the light-absorbing heat-conducting substrate,

and the evaporation light source irradiates on one side of the light-absorbing heat-conducting substrate, which is far away from the auxiliary electrode film layer, and the auxiliary electrode film layer is evaporated on the substrate to be plated to form the pattern of the auxiliary electrode.

In some embodiments, preparing the auxiliary electrode comprises:

forming a light absorbing layer on a transparent substrate;

forming a light-heat conducting layer on one side of the light absorbing layer, which is away from the transparent substrate;

forming the auxiliary electrode film layer on one side of the light-heat conducting layer, which is far away from the transparent substrate;

a liquid crystal shading and light transmitting layer is arranged on one side of the transparent substrate, which is far away from the auxiliary electrode film layer;

the substrate to be plated is arranged on one side of the auxiliary electrode film layer, which is far away from the transparent substrate, and the substrate to be plated is arranged opposite to the auxiliary electrode film layer, the vapor plating light source is arranged on one side of the liquid crystal shading light-transmitting layer, which is far away from the transparent substrate, and light emitted by the vapor plating light source passes through a light-transmitting area in the liquid crystal shading light-transmitting layer, so that the auxiliary electrode film layer corresponding to the light-transmitting area is evaporated and vapor plated to the corresponding area of the substrate to be plated.

The invention has the beneficial effects that: according to the display panel provided by the embodiment of the disclosure, on one hand, the impedance of the second electrode can be reduced by arranging the auxiliary electrode which is in contact with and is electrically connected with the second electrode, so that the driving voltage loss of the light-emitting unit caused by the larger impedance of the second electrode is reduced, the display brightness of the light-emitting unit at different positions of the display panel is enabled to be uniform, and the display effect of the display panel is improved; on the other hand, by arranging the auxiliary electrode at least at the position corresponding to the separation groove in the pixel definition layer, the depth morphology difference of the separation groove and the suspension groove in the pixel definition layer of the OLED display panel in the related art can be repaired and improved, so that the puncture difference of the second electrode in different OLED display panels is repaired and improved, the display color cast of the OLED display panels at different positions on the same silicon wafer is improved or eliminated, the display picture colors of the OLED display panels at different positions on the same silicon wafer tend to be consistent, and the quality difference of the display panels in the same batch is reduced.

According to the display device provided by the embodiment of the disclosure, by adopting the display panel in the embodiment, on one hand, the display brightness of different positions of the display device tends to be uniform, and the display effect of the display device is improved; on the other hand, the display color cast of the display device of the same batch is improved or eliminated, and the quality difference of the display device of the same batch is reduced.

Drawings

The accompanying drawings are included to provide a further understanding of embodiments of the disclosure, and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure, without limitation to the disclosure. The above and other features and advantages will become more readily apparent to those skilled in the art by describing in detail exemplary embodiments with reference to the attached drawings, in which:

FIG. 1a is a partial cross-sectional view of one embodiment of a related art silicon-based OLED display panel.

FIG. 1b is a schematic diagram of an OLED display panel located at different positions on the same silicon wafer.

Fig. 1c is a circuit diagram of a pixel circuit in a silicon-based OLED display panel.

Fig. 1d is an equivalent circuit diagram of the pixel circuit in fig. 1 c.

FIG. 1e is a schematic diagram of the display brightness of a central region in a display area of an OLED display panel according to the related art;

Fig. 2a is a partial cross-sectional view of one implementation of a display panel in an embodiment of the disclosure.

Fig. 2b is an enlarged view of a portion a of fig. 2 a.

Fig. 2c is another enlarged partial view of the portion a of fig. 2 a.

Fig. 2d is a schematic structural diagram of a light emitting unit in a display panel according to an embodiment of the disclosure.

Fig. 2e is a partial cross-sectional view of a portion of a film layer in a display panel according to an embodiment of the disclosure.

Fig. 2f is a partial top view of a display panel in an embodiment of the disclosure.

Fig. 3a is a graph showing contrast of brightness effect by setting the center position and the edge position of the display area of the auxiliary electrode display panel in the embodiment of the present disclosure.

Fig. 3b is a diagram showing actual display effect of the display panel by providing the auxiliary electrode in the embodiment of the disclosure.

Fig. 4a is a schematic view illustrating the preparation of a display panel according to an embodiment of the disclosure.

Fig. 4b is a schematic diagram illustrating a specific manufacturing process of the display panel according to an embodiment of the disclosure.

Fig. 4c is a schematic diagram illustrating the vapor deposition of auxiliary electrodes at different positions by adjusting the position of the light-transmitting region of the liquid crystal light-shielding and transmitting layer in the embodiment of the disclosure.

Detailed Description

In order to enable those skilled in the art to better understand the technical solutions of the embodiments of the present disclosure, a display panel, a manufacturing method thereof and a display device provided by the embodiments of the present disclosure are described in further detail below with reference to the accompanying drawings and detailed description.

Embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments shown may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

The embodiments of the present disclosure are not limited to the embodiments shown in the drawings, but include modifications of the configuration formed based on the manufacturing process. Thus, the regions illustrated in the figures have schematic properties and the shapes of the regions illustrated in the figures illustrate specific shapes of the regions, but are not intended to be limiting.

The same reference numerals in the drawings denote the same or similar structures, and thus detailed descriptions thereof will be omitted. Furthermore, the drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale.

The terms "a," "an," "the," "said" and "at least one" are used to indicate the presence of one or more elements/components/etc.; the terms "comprising" and "having" are intended to be inclusive and mean that there may be additional elements/components/etc. in addition to the listed elements/components/etc.; the terms "first," "second," and "third," etc. are used merely as labels, and do not limit the number of their objects.

The silicon-based OLED micro-display uses monocrystalline silicon as a substrate, integrates a CMOS drive circuit, and is a micro-display technology combining a semiconductor and an OLED. The pixel point of the silicon-based OLED is directly placed on the silicon wafer, the pixel size can be smaller, and the pixel density is higher, so that one of the advantages of the silicon-based OLED in the micro-display field is that the extremely high pixel density can be achieved by extremely small physical size, and the ultra-high PPI (resolution ratio) can be realized.

A silicon-based OLED generally has a plurality of OLED display panels fabricated on a silicon wafer, so as to realize mass production of the silicon-based OLED display panels.

In the related art, a silicon-based OLED display panel includes a driving back plate and a light emitting layer, wherein: the light emitting layer is disposed on one side of the driving back plate and includes a plurality of light emitting units, the light emitting units may include one or more light emitting devices connected in series, the light emitting devices may be organic light emitting diodes, and may include a first electrode (anode), a light emitting layer, and a second electrode (cathode) sequentially stacked in a direction away from the driving back plate, and the light emitting layer may be driven to emit light by applying an electrical signal to the first electrode and the second electrode, and specific light emitting principles of the light emitting devices will not be described herein.

In addition, the light-emitting layers of the light-emitting devices can be formed through direct evaporation through a fine mask (FMM), and the light-emitting layers of the light-emitting devices are distributed at intervals and emit light independently, so that color display is realized. But it is difficult to achieve high PPI (pixel density) due to limitations of fine reticle manufacturing processes. Therefore, color display can be realized by matching monochromatic light or white light with a color film, namely, each light-emitting device shares the same continuous light-emitting layer, the light-emitting layer can emit white light or other monochromatic light, the color film layer is provided with a plurality of light-filtering parts which are in one-to-one correspondence with the light-emitting units, one light-filtering part and the corresponding light-emitting units can form one sub-pixel, the plurality of sub-pixels form one pixel, the colors of light rays which can be transmitted by different light-filtering parts can be different, and the light-emitting colors of different sub-pixels can be different. The same pixel includes a plurality of sub-pixels having different colors, for example, a pixel may include three sub-pixels having red, green, and blue emission colors, respectively. Thereby, color display can be realized by a plurality of pixels.

However, if the light emitting layer has a continuous overall structure, electric leakage is likely to occur between the light emitting unit and the surrounding light emitting units, resulting in cross color. Each light emitting unit may include a plurality of light emitting devices connected in series, each light emitting device of the same light emitting unit shares a first electrode and a second electrode, a plurality of light emitting sublayers are provided between the first electrode and the second electrode, and at least two adjacent two light emitting sublayers may be connected in series through a charge generating layer. Positive charges (holes) can be transferred between two adjacent light emitting units through the charge generating layer, for example, when the light emitting unit corresponding to the red filtering portion in the color film layer emits light, the light emitting unit corresponding to the green filtering portion in the color film layer emits light due to the influence of electric leakage, so that the light emitting purity of a single pixel is reduced, and the color gamut of the whole display panel is reduced.

In the related art, as shown in fig. 1a, a partial cross-sectional view of an embodiment of a related art silicon-based OLED display panel is shown, wherein the display panel may include a driving back plane BP, a first electrode layer FE, a pixel defining layer PDL, a light emitting layer OL, and a second electrode CAT, wherein: the first electrode layer FE is disposed on a side surface of the driving back plate BP, and includes a plurality of first electrodes ANO distributed at intervals. The pixel defining layer PDL and the first electrode layer FE are disposed on the same side of the driving back plate BP, and expose each first electrode ANO; the pixel definition layer PDL includes a first insulating layer PBR and a second insulating layer PCL stacked in a direction away from the driving back plate BP, the first insulating layer PBR having a thickness smaller than the first electrode layer FE and being located outside the first electrode ANO; the second insulating layer PCL is provided with a separation groove SES located outside the first electrode ANO, and a suspension groove CUS1 is provided on a side wall of the separation groove SES. The light emitting layer OL covers the second insulating layer PCL and the first electrode layer FE. The second electrode CAT covers the light emitting layer OL.

As shown in fig. 1a, any first electrode ANO of the silicon-based OLED display panel and its corresponding light-emitting layer OL and second electrode CAT may form a light-emitting unit SUP, and the pixel defining layer PDL may separate each light-emitting unit SUP to define the range of each light-emitting unit SUP. Because the sidewall of the separation groove SES is provided with the suspension groove CUS1, the light-emitting layer OL is difficult to continuously form in the suspension groove CUS1 even if the light-emitting layer OL is sunken into the separation groove SES, i.e. at least part of the film layer of the light-emitting layer OL can be disconnected in the suspension groove CUS1, thereby reducing the risk of mutual electric leakage between adjacent light-emitting units SUP and improving cross color.

In some embodiments, as shown in fig. 1a, the driving back plate BP may include a pixel region and a peripheral region, and the peripheral region is located outside the pixel region and may be disposed around the pixel region. The driving back plate BP is used to form a driving circuit for driving the light emitting units SUP to emit light, and the driving circuit may include a pixel circuit and a peripheral circuit, wherein: the number of the pixel circuits and the light emitting units SUP may be plural, and at least a part of the pixel circuits are located in the pixel region, and the pixel circuits may be nTmC pixel circuits, for example, pixel circuits such as 2T1C, 4T1C, etc., as long as the light emitting units SUP can be driven to emit light, and the structure thereof is not particularly limited. The number of pixel circuits is the same as the number of first electrodes ANO and is connected to the first electrodes ANO in a one-to-one correspondence so as to control the respective light emitting units SUP to emit light, respectively. Where nTmC denotes that one pixel circuit includes n transistors (denoted by the letter "T") and m capacitors (denoted by the letter "C"). Of course, the same pixel circuit may also drive a plurality of light emitting units SUP.

The peripheral circuit is located in the peripheral area and connected with the pixel circuit. The peripheral circuit may include a light emission control circuit, a gate driving circuit, a source driving circuit, and the like, and may further include a power supply circuit connected to the second electrode CAT for inputting a power supply signal to the second electrode CAT. The peripheral circuit may input signals to the first electrode ANO and the second electrode CAT through the pixel circuit, thereby causing the light emitting unit SUP to emit light.

In some embodiments, as shown in fig. 1a, the driving back plate BP may include a substrate SU, the substrate SU may be a silicon substrate, the driving circuit may be formed on the silicon substrate through a semiconductor process, for example, the pixel circuit and the peripheral circuit may each include a plurality of transistors, and a well region WL may be formed in the silicon substrate through a doping process, where the well region WL has two doped regions DR that are spaced apart. Taking a well WL as an example: the GATE electrode GATE is arranged on one side of the driving backboard BP, the orthographic projection of the GATE electrode GATE on the driving backboard BP is positioned between two doped regions DR, the well region WL and the GATE electrode GATE can form a transistor, the doped regions DR of the well region WL are respectively a first pole and a second pole of the transistor, and the well region WL between the two doped regions DR is a channel region of the transistor.

The driving back plate BP may further include at least one trace layer TL and a flat layer PLN, the trace layer TL is disposed on one side of the substrate SU, the flat layer PLN covers the trace layer TL, and at least one trace layer TL is connected to each doped region DR.

For example: as shown in fig. 1a, the number of the trace layers TL is two, and the trace layers TL are located in the flat layer PLN, for example, the trace layers TL include a first trace layer TL1 and a second trace layer TL2, the first trace layer TL1 is disposed on one side of the substrate SU, and a portion of the flat layer PLN is disposed between the first trace layer TL and the substrate SU. The second trace layer TL2 is disposed on a side of the first trace layer TL1 facing away from the substrate SU, and is separated from the first trace layer TL1 by a portion of the planar layer PLN, and at least a portion of the area of the second trace layer TL2 is connected to the first trace layer TL 1.

Each trace layer TL may be formed by a sputtering process. The material of the planar layer PLN may be silicon oxide, silicon oxynitride or silicon nitride, which is formed layer by layer through a plurality of deposition and polishing processes, that is, the planar layer PLN may be formed by stacking a plurality of insulating film layers.

As shown in fig. 1a, the light emitting units SUP of the display panel are distributed on the side of the driving back plate BP, for example, the light emitting units SUP are disposed on the surface of the flat layer PLN facing away from the substrate SU. Each light emitting unit SUP may include a first electrode ANO, a second electrode CAT, and a light emitting layer OL disposed between the first electrode ANO and the second electrode CAT, where the first electrode ANO and the second electrode CAT may be connected to the trace layer TL, and a driving signal is applied to the first electrode ANO through the driving back plate BP, and a power signal is applied to the second electrode CAT, so as to drive the light emitting layer OL to emit light.

In order to realize color display, each light emitting unit SUP can emit light rays with the same color, and the color display is realized by matching with a color film layer CF positioned on one side of the second electrode CAT away from the driving back plate BP.

In some embodiments of the present disclosure, as shown in fig. 1a, a plurality of light emitting units SUP may be formed by a first electrode layer FE, a pixel defining layer PDL, a light emitting layer OL, and a second electrode CAT, wherein: the first electrode layer FE is disposed on a side of the driving back plate BP, for example, the first electrode layer FE is disposed on a surface of the planar layer PLN facing away from the substrate SU. The first electrode layer FE may include a plurality of first electrodes ANO distributed at intervals, where a front projection of each first electrode ANO on the driving back plate BP is located in a pixel area and connected to a pixel circuit, and one first electrode ANO is connected to one pixel circuit.

The first electrode layer FE may have a single-layer or multi-layer structure, and the material thereof is not particularly limited herein. For example:

as shown in fig. 1a, in some embodiments of the present disclosure, the first electrode ANO may include a first conductive layer ANO1, a second conductive layer ANO2, and a third conductive layer ANO3 sequentially stacked in a direction away from the driving back plate BP, wherein: the first conductive layer ANO1 and the third conductive layer ANO3 may be made of metal, metal oxide, or the like, for example, titanium nitride, or the like, and may be made of the same material or different materials. The second conductive layer ANO2 may be made of a metal material different from that of the first and third conductive layers ANO1 and ANO3, and has a lower resistivity than the first and third conductive layers ANO1 and ANO3, and for example, the material of the second conductive layer ANO2 may be aluminum.

In other embodiments of the present disclosure, the first electrode ANO may further include a fourth conductive layer, which may be disposed on a surface of the third conductive layer facing away from the driving back plate BP, and the fourth conductive layer may be made of a transparent conductive material such as ITO (indium tin oxide).

As shown in fig. 1a, the pixel defining layer PDL and the first electrode layer FE are disposed on the same surface of the driving back plate BP, i.e. the surface of the flat layer PLN facing away from the substrate SU, and the pixel defining layer PDL exposes each first electrode ANO. Specifically, the pixel defining layer PDL may be provided with a plurality of pixel openings PO exposing the respective first electrodes ANO.

The orthographic projection of any pixel opening PO on the driving back plate BP may be located within the exposed first electrode ANO thereof, that is, the pixel opening PO is not larger than the exposed first electrode ANO thereof, for example: the boundary of the pixel opening PO is located inside the boundary of the exposed first electrode ANO, i.e., the area of the pixel opening PO is smaller than the area of the exposed first electrode ANO.

The shape of the pixel opening PO may be a polygon such as a rectangle, a pentagon, a hexagon, etc., but is not necessarily a regular polygon, and the shape of the pixel opening PO may be another shape such as an ellipse, etc., and is not particularly limited herein.

As shown in fig. 1a, the light emitting layer OL covers the pixel defining layer PDL and the first electrode ANO, and the region where the light emitting layer OL and the first electrode ANO are stacked is used to form the light emitting units SUP, that is, the light emitting units SUP may share the same light emitting layer OL, and the portions of the light emitting layer OL stacked on different first electrodes ANO belong to different light emitting units SUP. Further, since the light emitting layer OL is shared by the light emitting units SUP, the light emitting colors of the different light emitting units SUP are the same.

As shown in fig. 1a, the second electrode CAT covers the light emitting layer OL, and the orthographic projection of the second electrode CAT on the driving back plate BP can cover the pixel region and extend into the peripheral region. The individual light emitting units SUP may share the same second electrode CAT. The light emitting layer OL may be controlled to emit light by controlling the voltage of the power signal input to the second electrode CAT and the driving signal input to the first electrode ANO.

As shown in fig. 1a, the display panel may further include a color film CF, which may be disposed on a side of the second electrode CAT facing away from the driving back plate BP, and includes a plurality of filter portions CFU, where each of the first electrodes ANO and each of the filter portions CFU are disposed opposite to each other in a direction perpendicular to the driving back plate BP, that is, an orthographic projection of one of the filter portions CFU on the driving back plate BP is at least partially overlapped with one of the first electrodes ANO. Each filter CFU includes at least three color filter CFU, for example, a red-light-transmissive filter CFU, a green-light-transmissive filter CFU, and a blue-light-transmissive filter CFU. After the light emitted by each light emitting unit SUP passes through the filtering function of the filtering part CFU, monochromatic light with different colors can be obtained, so as to realize color display, wherein one filtering part CFU and the corresponding light emitting unit SUP can form a sub-pixel, the color of any sub-pixel light is the color of the light transmitted by the filtering part CFU, a plurality of sub-pixels can form a pixel, and the light emitting colors of the sub-pixels of the same pixel are different.

The color film layer CF may further include a light shielding portion separating the filter portion CFU, where the light shielding portion is opaque and shields a region between the two light emitting units SUP. The filter part CFU can be directly arranged at intervals with the filter part CFU by adopting a shading material; alternatively, as shown in fig. 1a, in some embodiments of the present disclosure, adjacent filter portions CFU may be stacked in a region corresponding to between two adjacent light emitting units SUP, and the colors of the light transmitted by the two light emitting units are different, so that the stacked region is opaque.

In addition, in some embodiments of the present disclosure, in order to enhance the brightness of the picture, the color film CF may further include a transparent portion disposed opposite to the light emitting unit SUP in a direction perpendicular to the substrate on the basis that the light emitting layer OL emits white light, so that the color film CF may further transmit the white light and the brightness may be enhanced by the white light.

In order to improve the light extraction efficiency, the side of the second electrode CAT facing away from the driving back plate BP may be covered with a light extraction layer to improve the brightness, and further, the surface of the second electrode CAT facing away from the driving back plate BP may be directly covered with the light extraction layer.

In order to facilitate connection of the second electrode CAT to the driving circuit, in some embodiments of the present disclosure, the first electrode layer FE further includes a transfer ring, where an orthographic projection of the transfer ring on the driving back plate BP is located in the peripheral area, and the transfer ring may be connected to the peripheral circuit and surrounds the pixel area. The second electrode CAT may be connected to the adapter ring such that the second electrode CAT may be connected to the peripheral circuit through the adapter ring so that the peripheral circuit applies a driving signal to the second electrode CAT. The pattern of the transfer ring may be the same as the pattern of the first electrode ANO in the pixel region so as to improve the uniformity of the pattern of the first electrode layer FE.

In some embodiments of the present disclosure, as shown in fig. 1a, the display panel of the present disclosure may further include a first encapsulation layer TFE1, which may be disposed on a side of the second electrode CAT facing away from the driving back plate BP, and between the color film layer CF and the second electrode CAT, for blocking corrosion of external water and oxygen. The first encapsulation layer TFE1 may have a single-layer or multi-layer structure, for example, the first encapsulation layer TFE1 may include a first encapsulation sub-layer, a second encapsulation sub-layer, and a third encapsulation sub-layer sequentially stacked in a direction away from the driving back plate BP, wherein materials of the first encapsulation sub-layer and the second encapsulation sub-layer may be inorganic insulating materials such as silicon nitride, silicon oxide, and the second encapsulation sub-layer may be formed by an ALD (Atomic layer deposition ) process; the material of the third encapsulation sub-layer may be an organic material, which may be formed using an MLD (Molecular Layer Deposition ) process. Of course, other structures of the first encapsulation layer TFE1 may be adopted, and the structure of the first encapsulation layer TFE1 is not particularly limited herein.

In addition, in some embodiments of the present disclosure, as shown in fig. 1a, the display panel of the present disclosure may further include a second encapsulation layer TFE2, which may cover a surface of the color film layer CF facing away from the driving back plate BP, so as to achieve planarization, facilitate covering of the transparent cover plate, and may improve the encapsulation effect, and further block water and oxygen. The second encapsulation layer may have a single-layer or multi-layer structure, and may include inorganic materials such as silicon nitride and silicon oxide, or may include organic materials, and the structure of the second encapsulation layer is not particularly limited.

In addition, the display panel may further include a transparent cover plate, which may cover a side of the second encapsulation layer TFE2 facing away from the driving back plate BP, and the transparent cover plate may have a single-layer or multi-layer structure, and the material thereof is not particularly limited herein.

In the related art, since the second insulating layer PCL is relatively thin at the position of the suspended groove CUS1 in the isolation groove SES, the second electrode CAT is easily penetrated at the position to contact with the light emitting layer OL (such as the charge generation layer CGL in the light emitting layer OL), resulting in leakage and cross color phenomena at low gray scale. FIG. 1b is a schematic diagram of an OLED display panel located at different positions on the same silicon wafer; due to the limitation of the preparation process, the depth morphology of the separation grooves SES is different between different OLED display panels positioned at the center position and the edge position of the same silicon wafer, so that the penetration of the second electrode CAT in the different OLED display panels is different, and the display picture of the silicon-based OLED display panel positioned at the center position of the same silicon wafer is bluish, and the display picture of the silicon-based OLED display panel positioned at the edge position of the same silicon wafer is yellowish.

In addition, in the related art, in order to ensure a high PPI display effect of the silicon-based OLED display panel, a voltage driving manner is generally adopted in a pixel circuit for driving a sub-pixel (i.e., a light emitting unit) to emit light in the silicon-based OLED display panel, where a driving voltage between a first electrode and a second electrode of the light emitting unit is controlled to realize a gray level, and the voltage driving manner has a high limitation and requirement on a voltage drop between the first electrode (i.e., an anode) and the second electrode (i.e., a cathode) due to a high self-impedance of the second electrode (i.e., a cathode) of a large-size product, and the voltage drop between the first electrode (i.e., an anode) and the second electrode (i.e., a cathode) is increased due to a high self-impedance of the second electrode (i.e., a cathode), which may cause non-uniformity of display brightness of the light emitting unit at different positions of the silicon-based OLED display panel and affect a display effect.

As shown in fig. 1c and 1d, fig. 1c is a circuit diagram of a pixel circuit in a silicon-based OLED display panel, and fig. 1d is an equivalent circuit diagram of the pixel circuit in fig. 1 c; the driving principle of the pixel circuit in the silicon-based OLED display panel is as follows: the source electrode of the driving transistor DTFT in the pixel circuit is used for realizing different gray scale display of the OLED light-emitting unit EL, the precondition of the source electrode following is that a large resistor is connected in series in a closed loop formed by the driving transistor DTFT and the OLED light-emitting unit EL, so that the current flowing through the OLED light-emitting unit EL is in the nA-pA level, and the voltage of the source electrode s of the driving transistor DTFT is changed along with the change of the voltage of the grid electrode b due to the fact that the resistance of the OLED light-emitting unit EL is in the MΩ level, so that the voltage of the drain electrode a of the driving transistor DTFT is changed along with the change of the voltage of the grid electrode b, and the voltage difference VEL between the voltage Va of the drain electrode a (namely the anode voltage of the OLED light-emitting unit EL) and the cathode voltage Vss of the OLED light-emitting unit EL enables the OLED light-emitting unit EL to generate different brightness gray scales.

FIG. 1e is a schematic diagram showing the display brightness of a B region in a display area of an OLED display panel according to the related art; if the cathode voltage of the OLED light emitting unit in the OLED display panel is inputted from the lower edge S1, the cathode voltage drop along the long side direction Y of the display area AA in fig. 1e is the largest according to the voltage driving principle, so that the voltage drop and the voltage loss caused by the impedance of the cathode in the position of the center position area P of the display area AA in the long side direction Y of the display area AA in fig. 1e are the largest, and the brightness of the OLED light emitting unit in the position of the center position area P of the display area AA in the long side direction Y of the display area AA is the lowest, so that the impedance of the cathode of the whole OLED light emitting unit in the display area AA needs to be lowered.

Taking the 0.71"OLED display panel as an example, if a single-layer light emitting device (i.e. an OLED light emitting device is formed by stacking a hole transport layer, a light emitting layer and an electron transport layer) is used, when the brightness reaches 2000nit, the current density will reach 100mA/cm ² If the OLED light-emitting unit adopts a Top emission (Top EM) light-emitting mode, and the cathode is an entire cathode made of IZO (indium doped zinc oxide) material, the impedance of the cathode can reach rs=40 ohms each side, the voltage loss is close to 2V, and the gray scale which can be realized by the data signal voltage for driving the OLED light-emitting unit to emit light cannot be satisfied under the premise of a limited data signal voltage range. In the case of a large size silicon-based OLED display panel, the voltage loss due to cathode resistance is more significant, e.g., a 1.3 "OLED display panel is equivalent to a cathode voltage loss of approximately 4 071" OLED display panels.

Against this background, there is a need to minimize the cathode resistance of the OLED light emitting cells in a silicon-based OLED display panel.

In order to solve the foregoing problems in the related art, in a first aspect, an embodiment of the present disclosure provides a display panel, referring to fig. 2a, which is a partial cross-sectional view of an implementation of the display panel in the embodiment of the present disclosure, including: driving the backboard BP; the first electrode layer FE is arranged on one side surface of the driving backboard BP and comprises a plurality of first electrodes ANO which are distributed at intervals; the pixel definition layer PDL is positioned on one side of the first electrode layer FE, which is far away from the driving backboard BP, and is provided with a plurality of pixel openings PO, and each first electrode ANO is exposed at the pixel opening PO; a plurality of separation grooves SES are further formed in one side, away from the driving backboard BP, of the pixel definition layer PDL, and orthographic projection of the separation grooves SES on the driving backboard BP is not overlapped with orthographic projection of the first electrode ANO on the driving backboard BP; the light-emitting layer OL is positioned on one side of the pixel definition layer PDL, which is far away from the driving back plate BP, and the orthographic projection of the light-emitting layer OL on the driving back plate BP covers the pixel definition layer PDL and the first electrode layer FE; the second electrode CAT is positioned at one side of the luminous layer OL, which is far away from the driving backboard BP, and the orthographic projection of the second electrode CAT on the driving backboard BP covers the luminous layer OL; the auxiliary electrode FZ is located at a side of the second electrode CAT facing away from the driving back plate BP, is in contact with and electrically connected with the second electrode CAT, the orthographic projection of the auxiliary electrode FZ on the driving back plate BP is located in the orthographic projection area of the pixel defining layer PDL on the driving back plate BP, and the orthographic projection of the auxiliary electrode FZ on the driving back plate BP at least covers the separation groove SES.

In the display panel of this embodiment, any one of the first electrodes ANO, the corresponding light-emitting layer OL and the second electrode CAT may form a light-emitting unit SUP, and the pixel defining layer PDL may separate the light-emitting units SUP to define the range of each light-emitting unit SUP. The first electrode ANO may serve as an anode of the light emitting unit SUP and the second electrode CAT may serve as a cathode of the light emitting unit SUP.

On the one hand, by arranging the auxiliary electrode FZ in contact with and electrically connected with the second electrode CAT, the impedance of the second electrode CAT can be reduced, so that the driving voltage loss of the light emitting unit SUP caused by the larger impedance of the second electrode CAT is reduced, the display brightness of the light emitting unit SUP at different positions of the display panel tends to be uniform, and the display effect of the display panel is improved; on the other hand, by arranging the auxiliary electrode FZ at least at the position corresponding to the separation groove SES in the pixel definition layer PDL, the depth morphology difference of the separation groove and the suspension groove in the pixel definition layer of the OLED display panel in the related art can be repaired and improved, so that the puncture difference of the second electrode CAT in different OLED display panels is repaired and improved, the display color shift of the OLED display panels at different positions on the same silicon wafer is improved or eliminated, the display picture colors of the OLED display panels at different positions on the same silicon wafer tend to be consistent, and the quality difference of the display panels in the same batch is reduced.

In some embodiments, referring to FIG. 2b, there is shown an enlarged partial view of portion A of FIG. 2 a; the auxiliary electrode FZ comprises a first part FZ1 and a second part FZ2, the first part FZ1 and the second part FZ2 are connected into a whole, the second part FZ2 is positioned on two opposite sides of the first part FZ1, the front projection of the first part FZ1 on the driving backboard BP coincides with the front projection of the separation groove SES on the driving backboard BP, the front projection of the second part FZ2 on the driving backboard BP does not overlap with the front projection of the separation groove SES on the driving backboard BP, and the thickness of the first part FZ1 is larger than that of the second part FZ 2.

In some embodiments, referring to fig. 2b, the surface of the first portion FZ1 facing away from the driving back plate BP smoothly transitions with the surface of the second portion FZ2 facing away from the driving back plate BP. The sharp corners are avoided on the sides of the second electrode CAT and the auxiliary electrode FZ facing away from the driving back plate BP.

In some embodiments, referring to fig. 2b, a distance h1 between a surface of the first portion FZ1 facing away from the driving back plate BP and the driving back plate BP is greater than or equal to a distance h2 between a surface of the second portion FZ2 facing away from the driving back plate BP and the driving back plate BP. I.e. the surface of the first portion FZ1 facing away from the driving back plate BP is higher than the surface of the second portion FZ2 facing away from the driving back plate BP, or the surface of the first portion FZ1 facing away from the driving back plate BP is flush with the surface of the second portion FZ2 facing away from the driving back plate BP; by the arrangement, on one hand, depth morphology differences of separation grooves and suspension grooves in pixel definition layers of the OLED display panels in the related art can be repaired and improved, so that puncture differences of the second electrodes CAT in different OLED display panels are repaired and improved, display color cast of the OLED display panels at different positions on the same silicon wafer is improved or eliminated, display picture colors of the OLED display panels at different positions on the same silicon wafer tend to be consistent, on the other hand, the surface of one side of the auxiliary electrode FZ, which is far away from the driving backboard BP, and the surface of one side of the second electrode CAT, which is far away from the driving backboard BP, are basically leveled or tend to be leveled, and sharp edges and corners are prevented from being formed on one sides of the second electrode CAT and the auxiliary electrode FZ, which are far away from the driving backboard BP.

In some embodiments, referring to fig. 2b, the surface of the second electrode CAT facing away from the driving backplate BP smoothly transitions with the surface of the second portion FZ2 facing away from the driving backplate BP. By the arrangement, the surface of one side of the auxiliary electrode FZ, which is far away from the driving backboard BP, is basically leveled or tends to be leveled with the surface of one side of the second electrode CAT, which is far away from the driving backboard BP, so that sharp edges and corners are prevented from being formed on one side of the second electrode CAT and the auxiliary electrode FZ, which is far away from the driving backboard BP.

In some embodiments, referring to fig. 2b, a distance h2 between a surface of the second portion FZ2 facing away from the driving backplate BP and the driving backplate BP is greater than or equal to a distance h3 between a surface of the second electrode CAT facing away from the driving backplate BP and the driving backplate BP. By the arrangement, the surface of one side of the auxiliary electrode FZ, which is far away from the driving backboard BP, is basically leveled or tends to be leveled with the surface of one side of the second electrode CAT, which is far away from the driving backboard BP, so that sharp edges and corners are prevented from being formed on one side of the second electrode CAT and the auxiliary electrode FZ, which is far away from the driving backboard BP.

In some embodiments, referring to fig. 2b, the thickness of the first portion FZ1 is greater than the thickness of the second electrode CAT, and the thickness of the second portion FZ2 is less than the thickness of the second electrode CAT. By the arrangement, on one hand, depth morphology differences of separation grooves and suspension grooves in pixel definition layers of the OLED display panels in the related art can be repaired and improved, so that puncture differences of the second electrodes CAT in different OLED display panels are repaired and improved, display color cast of the OLED display panels at different positions on the same silicon wafer is improved or eliminated, display picture colors of the OLED display panels at different positions on the same silicon wafer tend to be consistent, on the other hand, the surface of one side of the auxiliary electrode FZ, which is far away from the driving backboard BP, and the surface of one side of the second electrode CAT, which is far away from the driving backboard BP, are basically leveled or tend to be leveled, and sharp edges and corners are prevented from being formed on one sides of the second electrode CAT and the auxiliary electrode FZ, which are far away from the driving backboard BP.

In some embodiments, referring to fig. 2b, the ratio of the first portion FZ1 thickness to the second electrode CAT thickness ranges from 4:1 to 7:1, the ratio of the thickness of the second portion FZ2 to the thickness of the second electrode CAT ranges from 1: 3-1: 2. the first part FZ1 with the thickness is more beneficial to filling the separation groove SES in the pixel definition layer PDL, and is also more beneficial to repairing and improving the puncture difference of the second electrode CAT in different OLED display panels, so that the display color cast of the OLED display panels at different positions on the same silicon wafer is improved or eliminated; the second portion FZ2 of this thickness is more advantageous in making a side surface of the auxiliary electrode FZ facing away from the driving back plate BP substantially flush or tends to be flat with a side surface of the second electrode CAT facing away from the driving back plate BP, so that a sharp corner is more advantageously avoided on a side of the second electrode CAT and the auxiliary electrode FZ facing away from the driving back plate BP.

In some embodiments, referring to fig. 2b, the orthographic projection of the second portion FZ2 on the driving backplate BP partially overlaps the orthographic projection of the first electrode ANO on the driving backplate BP. Since the auxiliary electrode FZ is made of a metal material with low resistivity, the auxiliary electrode FZ can shield light, and the orthographic projection of the second portion FZ2 and the first electrode ANO is partially overlapped, so that a color mixing phenomenon between adjacent light emitting units SUP which are relatively close to each other can be improved or avoided, for example, light emitted by one light emitting unit SUP of the two adjacent light emitting units SUP enters a red color resistor, light emitted by the other light emitting unit SUP enters a green color resistor, and if light entering the red color resistor enters the green color resistor at the same time, poor color mixing of the two adjacent light emitting units SUP can be caused.

In some embodiments, referring to FIG. 2c, another partial enlarged view of portion A of FIG. 2 a; the orthographic projection of the second portion FZ2 on the driving back plate BP does not overlap with the orthographic projection of the first electrode ANO on the driving back plate BP. By this arrangement, the color mixing phenomenon between the adjacent light emitting units SUP which are far apart can be improved or avoided as well.

In some embodiments, referring to fig. 2a, the shortest distance s between the forward projection edge of the auxiliary electrode FZ on the driving back plate BP and the forward projection edge of the pixel opening PO adjacent thereto on the driving back plate BP ranges from 0.3 to 0.5 μm. By this arrangement, on the one hand, the light emission rate of the light emitting units SUP can be ensured, and on the other hand, the color mixing phenomenon between the adjacent light emitting units SUP can be improved or avoided.

In some embodiments, referring to fig. 2a, the pixel defining layer PDL comprises a first insulating layer PBR and a second insulating layer PCL, which are stacked sequentially away from the driving back plate BP, the separation groove SES penetrates the thickness of the second insulating layer PCL, the first insulating layer PBR being exposed at the separation groove SES. By arranging the first insulating layer PBR, the depth of the separation groove SES can be limited, and the separation groove SES is prevented from extending into the driving back plate BP, namely, the depth of the separation groove SES is limited by the first insulating layer PBR, which is beneficial to improving the uniformity of the structures of different driving back plates BP.

In some embodiments, referring to fig. 2a, the second insulating layer PCL includes a first sub-layer CL1, a second sub-layer CL2 and a third sub-layer CL3, the first sub-layer CL1, the second sub-layer CL2 and the third sub-layer CL3 are stacked sequentially away from the driving back plate BP, a side of the second sub-layer CL2 serving as a groove wall of the separation groove SES is retracted relative to a side of the first sub-layer CL1 and the third sub-layer CL3 serving as a groove wall of the separation groove SES toward a direction approaching the pixel opening PO to form a suspension groove CUS1 between the first sub-layer CL1 and the third sub-layer CL3, the light emitting layer OL includes a plurality of light emitting sub-layers OLP stacked sequentially, and at least a part of the light emitting sub-layers OLP are disconnected at the suspension groove CUS 1.

In some embodiments, referring to fig. 2a and 2d, fig. 2d is a schematic structural diagram of a light emitting unit in a display panel according to an embodiment of the disclosure. The light emitting units SUP may include a plurality of light emitting devices LD connected in series, each light emitting unit SUP includes a first electrode ANO, a second electrode CAT, and a plurality of light emitting sublayers OLP between the first electrode ANO and the second electrode CAT, and each light emitting device LD of the same light emitting unit SUP may share the same first electrode ANO and the same second electrode CAT, that is, the same light emitting unit SUP may have only one first electrode ANO and one second electrode CAT.

For example: referring to fig. 2a and 2d, the light emitting layer OL may include a plurality of light emitting sub-layers OLP connected in series in a direction away from the driving back plate BP, at least one light emitting sub-layer OLP being connected in series with an adjacent light emitting sub-layer OLP through a charge generation layer CGL. When an electrical signal is applied to the first electrode ANO and the second electrode CAT, each light emitting sub-layer OLP can emit light, and different light emitting sub-layers OLP can be used to emit light of different colors.

In some embodiments, referring to fig. 2d, any light emitting sub-layer OLP may include a hole injection layer HIL, a hole transport layer HTL, a light emitting material layer EML, an electron transport layer ETL, and an electron injection layer EIL distributed in a direction away from the driving back plate BP, and specific light emitting principles will not be described in detail herein, wherein: the number of the hole injection layer HIL, the hole transport layer HTL, the electron transport layer ETL, and the electron injection layer EIL is not particularly limited herein, and adjacent light emitting sub-layers OLP may share one or more of the hole injection layer HIL, the hole transport layer HTL, the electron transport layer ETL, and the electron injection layer EIL. Meanwhile, a charge generation layer CGL may be disposed between at least two adjacent light emitting sub-layers OLP, thereby connecting the two light emitting sub-layers OLP in series.

In some embodiments, referring to fig. 2d, the light emitting layer OL may include three light emitting sub-layers OLP with different colors, namely a first light emitting sub-layer OLPr emitting red light, a second light emitting sub-layer OLPg emitting green light, and a third light emitting sub-layer OLPb emitting blue light, so that the light emitting layer OL emits white light when the first light emitting sub-layer OLPr, the second light emitting sub-layer OLPg, and the third light emitting sub-layer OLPb can emit light at the same time. The first light emitting sub-layer OLPr and the second light emitting sub-layer OLPg share the hole injection layer HIL, the hole transport layer HTL1, the electron transport layer ETL2 and the electron injection layer EIL, and the light emitting material layer G-EML of the second light emitting sub-layer OLPg is disposed on the surface of the light emitting material layer R-EML of the first light emitting sub-layer OLPr facing away from the driving back plate BP, so that the first light emitting sub-layer OLPr and the second light emitting sub-layer OLPg are directly connected in series without providing a special charge generation layer. The surface of the second light emitting sub-layer OLPg facing away from the driving back plate BP may be provided with a charge generation layer CGL. The third light emitting sub-layer OLPb shares the electron injection layer EIL with the first light emitting sub-layer OLPr and the second light emitting sub-layer OLPg, the hole injection layer HIL2 of the third light emitting sub-layer OLPb is disposed on the surface of the charge generation layer CGL facing away from the driving back plate BP, and one sides of the hole transport layer HTL2 and the hole transport layer HTL3 of the third light emitting sub-layer OLPb are laminated on one side of the charge generation layer CGL facing away from the driving back plate BP, so that the third light emitting sub-layer OLPb can be serially connected with the second light emitting sub-layer OLPg and the first light emitting sub-layer OLPr through the charge generation layer CGL. In addition, a hole first insulating layer HBL may be disposed between the electron transport layer hyt of the third light emitting sub-layer OLPb and the light emitting material layer BEML.

The above-mentioned light emitting layer OL structure in fig. 2d is only illustrative, and does not limit the film layer, and may include only two light emitting sub-layers OLP, or more, or only one light emitting sub-layer OLP, so long as the color display can be realized by matching with the color film layer CF.

In some embodiments, since the light emitting units SUP share the light emitting layer OL, carriers (e.g. holes) of the light emitting units SUP may move to other light emitting units SUP through the film layer such as the charge generation layer CGL, especially to adjacent light emitting units SUP, that is, electric leakage occurs, which affects the purity of light emission, resulting in color crosstalk. Therefore, referring to fig. 2a, by providing the separation groove SES in the second insulating layer PCL and providing the suspension groove CUS1 between the first sub-layer CL1 and the third sub-layer CL3 of the second insulating layer PCL, it is difficult for at least part of the light emitting sub-layer OLP in the light emitting layer OL to be continuous at the suspension groove CUS1, i.e., at least part of the light emitting sub-layer OLP in the light emitting layer OL is disconnected at the suspension groove CUS1, thereby preventing carriers from moving between the light emitting units SUP and further avoiding cross color due to electric leakage.

In some embodiments, referring to fig. 2b and 2c, the depth L of the suspension groove CUS1 is the thickness of the second sub-layer CL2, the width M of the suspension groove CUS1 is the distance between the orthographic projection of the side of the second sub-layer CL2 as the groove wall of the separation groove SES on the driving back plate BP and the orthographic projection of the side of the third sub-layer CL3 as the groove wall of the separation groove SES on the driving back plate BP, the thickness of the first portion FZ1 is greater than the depth L of the suspension groove CUS1, and the thickness of the first portion FZ1 is greater than the width M of the suspension groove CUS 1.

In some embodiments, the thickness of the first portion FZ1 is 1 to 2 times the depth L of the suspended groove CUS1, and the thickness of the first portion FZ1 is 0.5 to 1 times the width M of the suspended groove CUS 1. The thickness of the first portion FZ1 is too large relative to the depth L of the suspension groove CUS1, which is easy to cause poor packaging of the light emitting units SUP, and at the same time, too large depth L of the suspension groove CUS1 can cause severe penetration leakage of the second electrode CAT (i.e., cathode), and too small depth L of the suspension groove CUS1 can easily cause crosstalk of light emission between adjacent light emitting units SUP; in addition, the thickness of the first portion FZ1 is too large relative to the width M of the suspended groove CUS1, so that the upper wall (i.e., the third sub-layer CL 3) of the suspended groove CUS1 is easily crushed, and thus, the above-mentioned ratio setting can ensure good packaging of the light emitting units SUP, improve or avoid the penetration leakage phenomenon of the second electrode CAT (i.e., the cathode) and the light emitting crosstalk phenomenon between adjacent light emitting units SUP, and prevent the auxiliary electrode FZ from crushing the upper wall (i.e., the third sub-layer CL 3) of the suspended groove CUS 1.

In some embodiments, referring to fig. 2b and 2c, the thickness of the first insulating layer PBR is less than the thickness of the first electrode layer FE, and the thickness of the first insulating layer PBR is less than the thickness of the second insulating layer PCL. This provides sufficient recess space for the separation groove SES in the second insulating layer PCL.

For example, for the first electrode ANO including the first conductive layer ANO1, the second conductive layer ANO2, and the third conductive layer ANO3, the thickness of the first insulating layer PBR may be greater than the thickness of the first conductive layer ANO1, but less than the sum of the thicknesses of the second conductive layer ANO2 and the first conductive layer ANO1, that is, the surface of the first insulating layer PBR facing away from the driving back plate BP is located between the surface of the second conductive layer ANO2 facing away from the driving back plate BP and the first conductive layer ANO 1. The material of the first insulating layer PBR may be an inorganic insulating material such as silicon oxide or silicon nitride, but may be other insulating materials. In addition, the first insulating layer PBR may contact with the sidewall of the first electrode ANO, and since the material of the first insulating layer PBR is an insulating material, the first insulating layer PBR is not electrically connected with the first electrode ANO, so that a short circuit between adjacent first electrodes ANO is avoided.

In some embodiments, referring to fig. 2a, the second insulating layer PCL may be laminated on the surface of the first insulating layer PBR facing away from the driving back plate BP, and each first electrode ANO is exposed, and the sum of the thicknesses of the second insulating layer PCL and the first insulating layer PBR may be greater than the thickness of the first electrode layer FE.

In some embodiments, referring to fig. 2e, which is a partial cross-sectional view of a portion of a film layer in a display panel according to an embodiment of the disclosure, sidewalls of the pixel openings PO are slopes that expand in a direction away from the driving back plate BP, that is, a distance between the sidewalls of the pixel openings PO gradually increases in a direction away from the driving back plate BP, and a slope angle θ of the slopes is not greater than 90 °. In addition, the side walls of the separation groove SES may be slopes expanding in a direction away from the driving back plate BP, that is, the distance between the side walls of the separation groove SES gradually increases in a direction away from the driving back plate BP, and the slope angle α of the side walls of the separation groove SES is less than or equal to 90 °.

In some embodiments, referring to fig. 2e, a partial region of the second insulating layer PCL may extend onto the surface of the first electrode ANO facing away from the driving backplate BP, but not entirely cover the first electrode ANO. Accordingly, the second insulating layer PCL may include a cut-off portion PDLc and an extension portion PDLe, where the cut-off portion PDLc may be located outside the first electrode ANO, and the extension portion PDLe is located on a surface of the first electrode ANO facing away from the driving back plane BP, and there is an overlapping area between the pixel defining layer PDL and the orthographic projection of the first electrode ANO on the driving back plane BP. The pixel opening PO may be formed in the extension portion PDLe to expose the first electrode ANO. Because the thickness of the first electrode ANO is greater than that of the first insulating layer PBR, when the second insulating layer PCL extends from the cut-off portion PDLc to the extension portion PDLe, a climbing is required, that is, the surface of the extension portion PDLe facing away from the first electrode ANO is located at the side of the surface of the cut-off portion PDLc facing away from the driving back plate BP.

In some embodiments, the second insulating layer PCL may also include no extension portion PDLe, but only a truncated portion PDLc, which may separate the respective first electrodes ANO, that is, the boundaries of projection of the truncated portion PDLc and the first insulating layer PBR on the driving back plate BP may coincide. The pixel opening PO may be a through hole penetrating the cutoff portion PDLc and the first insulating layer PBR, and there is no overlapping area between the pixel defining layer PDL and the orthographic projection of the first electrode ANO on the driving back plate BP.

In some embodiments, referring to fig. 2f, a partial top view of a display panel in an embodiment of the present disclosure; the orthographic projection of the auxiliary electrode FZ on the driving back plate BP surrounds the orthographic projection of the pixel opening PO on the driving back plate BP.

In some embodiments, referring to fig. 2f, the second insulating layer PCL is provided with a separation groove SES, and the separation groove SES is located outside the first electrodes ANO, which may be an annular groove surrounding the first electrodes ANO, and each first electrode ANO may surround a separation groove SES. The separation grooves SES surrounded by the adjacent two first electrodes ANO may share a partial area, so that only one separation groove SES may exist between the adjacent two first electrodes ANO. Of course, the separation grooves SES surrounding the adjacent two first electrodes ANO may be formed independently, and there is no shared portion.

In some embodiments, referring to fig. 2f, the auxiliary electrode FZ is connected in a mesh. The auxiliary electrode FZ is made of a metal material with low resistivity such as Mo, AL, ti, etc., the second electrode CAT is made of an indium doped zinc oxide (IZO) material, and the impedance of the second electrode CAT (i.e., the cathode) can be reduced to the greatest extent by connecting the auxiliary electrode FZ and the second electrode CAT in parallel, so that the driving voltage loss of the light emitting unit SUP caused by the larger impedance of the second electrode CAT is reduced, the display brightness of the light emitting unit SUP at different positions of the display panel tends to be uniform, and the display effect of the display panel is improved.

In some embodiments, referring to fig. 3a, which is a graph showing the contrast of the display brightness effect by setting the center position and the edge position of the display area of the display panel with the auxiliary electrode in the embodiments of the disclosure, fig. 3b, which is a graph showing the actual display effect of the display panel with the auxiliary electrode in the embodiments of the disclosure, it can be seen from fig. 3a and 3b that when the voltage of the second electrode (i.e. the cathode) of the display panel is input from the peripheral edge of the display area, the brightness of the edge area of the display panel can be reduced and the uniformity of the overall brightness of the display area can reach more than 80% by setting the auxiliary electrode.

Other structures of the display panel in the embodiment of the present disclosure are the same as those of the display panel in fig. 1a, and will not be repeated here.

Based on the above structure of the display panel, the embodiment of the present disclosure further provides a method for manufacturing the display panel, and referring to fig. 4a, a schematic diagram of manufacturing the display panel in the embodiment of the present disclosure is shown; the preparation method comprises the following steps: step S01: and preparing a driving backboard.

Step S02: a first electrode layer, a pixel definition layer, a light emitting layer and a second electrode are sequentially prepared on one side of the driving backboard to form the substrate 1 to be plated.

Step S03: an auxiliary electrode FZ is prepared on the side of the second electrode facing away from the drive backplate.

Wherein, preparing the auxiliary electrode FZ includes: the auxiliary electrode film layer 2 is formed on the light-absorbing and heat-conducting substrate 3.

The vapor deposition light source 4 irradiates on one side of the light absorption and heat conduction substrate 3, which is far away from the auxiliary electrode film layer 2, and vapor deposition of the auxiliary electrode film layer 2 on the substrate 1 to be plated is carried out to form a pattern of an auxiliary electrode FZ.

In some embodiments, referring to fig. 4b, a schematic diagram of a specific manufacturing process of a display panel in an embodiment of the disclosure; wherein, preparing the auxiliary electrode FZ includes: step S031: a light absorbing layer 31 is formed on the transparent substrate 30.

In this step, the light absorbing layer 31 may be prepared by a conventional process such as a coating process. The light absorbing layer 31 absorbs light strongly.

Step S032: a light-heat conductive layer 32 is formed on a side of the light absorbing layer 31 facing away from the transparent substrate 30.

In this step, the light and heat conductive layer 32. Can be prepared by conventional processes such as coating processes. The light-heat conductive layer 32 has a good vertical heat conduction effect.

Step S033: an auxiliary electrode film layer 2 is formed on a side of the light-heat conductive layer 32 facing away from the transparent substrate 30.

In this step, a high-conductivity metal material is formed on the side of the light-heat conductive layer 32 facing away from the transparent substrate 30 by a conventional process such as coating, evaporation, sputtering, or printing.

Step S034: a liquid crystal light-shielding and transmitting layer 33 is provided on the side of the transparent substrate 30 facing away from the auxiliary electrode film layer 2.

In this step, the liquid crystal light-shielding and light-transmitting layer 33 controls the deflection direction of the liquid crystal in the liquid crystal light-shielding and light-transmitting layer 33 by the active driving electrode, so as to realize the light-transmitting and light-shielding functions of the liquid crystal in different areas of the liquid crystal light-shielding and light-transmitting layer 33.

Step S035: the substrate 1 to be plated is arranged on one side of the auxiliary electrode film layer 2, which is far away from the transparent base 30, and the substrate 1 to be plated is arranged opposite to the auxiliary electrode film layer 2, the vapor deposition light source 4 is arranged on one side of the liquid crystal shading light-transmitting layer 33, which is far away from the transparent base 30, and the light emitted by the vapor deposition light source 4 passes through the light-transmitting region in the liquid crystal shading light-transmitting layer 33, so that the auxiliary electrode film layer 2 corresponding to the light-transmitting region is evaporated and vapor deposited to the corresponding region of the substrate 1 to be plated, thereby forming the pattern of the auxiliary electrode FZ on the substrate 1 to be plated.

In this step, the vapor deposition light source 4 may be a UV light (ultraviolet light) source or a laser light source. The light emitted by the vapor deposition light source 4 passes through the light transmission area in the liquid crystal shading light transmission layer 33, so that the metal material corresponding to the light transmission area is evaporated and vapor deposited to the corresponding position on the substrate 1 to be plated according to the vertical direction.

Referring to fig. 4c, a schematic diagram of vapor deposition of auxiliary electrodes at different positions is implemented by adjusting the position of the light-transmitting region of the liquid crystal light-shielding and light-transmitting layer in the embodiment of the disclosure; the driving position of the liquid crystal shading and transmitting layer is adjusted, namely the positions of the transmitting area and the shading area of the liquid crystal shading and transmitting layer are changed, the whole auxiliary electrode film layer can be entirely used for forming the patterns of the auxiliary electrode on the substrate to be plated, so that the auxiliary electrode patterning is realized, the material waste is reduced to the greatest extent, and meanwhile, the preparation process difficulty of the auxiliary electrode is also reduced. For example, in fig. 4c, the evaporation of the auxiliary electrodes at the evaporation positions 1, 2 and 3 on the substrate 1 to be plated may be achieved by adjusting the driving position of the liquid crystal light-shielding and transmitting layer, and evaporating the auxiliary electrode film layers at different positions on the transparent substrate to be plated to three evaporation positions on the substrate 1 in sequence after three evaporation. The distribution mode of the auxiliary electrode can be adjusted theoretically, and the full utilization of the auxiliary electrode film layer on the transparent substrate is realized by adjusting the driving position of the liquid crystal shading and light transmitting layer and setting the evaporation times, so that the maximum utilization rate of materials is realized, and the material cost is saved.

In the embodiment of the present disclosure, the driving backboard and the preparation of each film layer on the driving backboard all adopt the conventional process, and are not described here again.

According to the display panel provided by the embodiment of the disclosure, on one hand, the impedance of the second electrode can be reduced by arranging the auxiliary electrode which is in contact with and is electrically connected with the second electrode, so that the driving voltage loss of the light-emitting unit caused by the larger impedance of the second electrode is reduced, the display brightness of the light-emitting unit at different positions of the display panel is enabled to be uniform, and the display effect of the display panel is improved; on the other hand, by arranging the auxiliary electrode at least at the position corresponding to the separation groove in the pixel definition layer, the depth morphology difference of the separation groove and the suspension groove in the pixel definition layer of the OLED display panel in the related art can be repaired and improved, so that the puncture difference of the second electrode in different OLED display panels is repaired and improved, the display color cast of the OLED display panels at different positions on the same silicon wafer is improved or eliminated, the display picture colors of the OLED display panels at different positions on the same silicon wafer tend to be consistent, and the quality difference of the display panels in the same batch is reduced.

In a second aspect, embodiments of the present disclosure further provide a display device including the display panel in the foregoing embodiments.

By adopting the display panel in the embodiment, on one hand, the display brightness of different positions of the display device tends to be uniform, and the display effect of the display device is improved; on the other hand, the display color cast of the display device of the same batch is improved or eliminated, and the quality difference of the display device of the same batch is reduced.

The display device provided by the embodiment of the disclosure can be any product or component with a display function, such as an OLED panel, an OLED television, an OLED billboard, a display, a mobile phone, a navigator and the like.

It is to be understood that the above embodiments are merely exemplary embodiments employed to illustrate the principles of the present disclosure, however, the present disclosure is not limited thereto. Various modifications and improvements may be made by those skilled in the art without departing from the spirit and substance of the disclosure, and are also considered to be within the scope of the disclosure.

Claims

1. A display panel, comprising:

a drive back plate;

2. The display panel of claim 1, wherein the auxiliary electrode comprises a first portion and a second portion, the first portion and the second portion being integrally connected,

the second portion is located on opposite sides of the first portion,

3. The display panel of claim 2, wherein a surface of the first portion facing away from the drive backplate smoothly transitions with a surface of the second portion facing away from the drive backplate.

4. A display panel according to claim 3, wherein the distance between the surface of the first portion facing away from the drive backplate and the drive backplate is greater than or equal to the distance between the surface of the second portion facing away from the drive backplate and the drive backplate.

5. A display panel according to claim 3, wherein a surface of the second electrode facing away from the driving backplate smoothly transitions with a surface of the second portion facing away from the driving backplate.

6. The display panel of claim 5, wherein a distance between a surface of the second portion facing away from the drive backplate and the drive backplate is greater than or equal to a distance between a surface of the second electrode facing away from the drive backplate and the drive backplate.

7. The display panel according to any one of claims 2-4, wherein a thickness of the first portion is greater than a thickness of the second electrode,

8. The display panel of claim 7, wherein a ratio of the first portion thickness to the second electrode thickness ranges from 4:1 to 7:1,

9. the display panel of claim 2, wherein an orthographic projection of the second portion on the driving backplate partially overlaps an orthographic projection of the first electrode on the driving backplate.

10. The display panel of claim 2, wherein an orthographic projection of the second portion on the driving backplate does not overlap with an orthographic projection of the first electrode on the driving backplate.

11. The display panel according to claim 1, wherein a shortest distance between an orthographic projection edge of the auxiliary electrode on the driving back plate and an orthographic projection edge of the pixel opening adjacent thereto on the driving back plate ranges from 0.3 to 0.5 μm.

12. The display panel of claim 2, wherein the pixel defining layer comprises a first insulating layer and a second insulating layer,

13. The display panel of claim 12, wherein the depth of the suspension trench is the thickness of the second sub-layer,

14. The display panel of claim 13, wherein the thickness of the first portion is 1-2 times the depth of the suspension groove,

15. The display panel of claim 12, wherein the first insulating layer has a thickness less than a thickness of the first electrode layer,

16. The display panel of claim 1, wherein the sidewalls of the pixel openings are sloping surfaces that diverge in a direction away from the drive backplate,

the slope angle of the slope is not more than 90 degrees.

17. The display panel of claim 1, wherein an orthographic projection of the auxiliary electrode on the driving backplate surrounds an orthographic projection of the pixel opening on the driving backplate.

18. The display panel of claim 17, wherein the auxiliary electrode connection is mesh-shaped.

19. A display device comprising the display panel of any one of claims 1-18.

20. A method of manufacturing a display panel, comprising:

Preparing a driving backboard;

the preparing of the auxiliary electrode includes:

21. The method of manufacturing a display panel according to claim 20, wherein manufacturing the auxiliary electrode comprises:

forming a light absorbing layer on a transparent substrate;