DISPLAY PANEL AND FABRICATION METHOD THEREOF, AND DISPLAY APPARATUS

A display panel, a fabrication method of the display panel, and a display apparatus are provided in the present disclosure. The display panel includes a substrate; a drive substrate on the substrate, where the drive substrate includes a first film layer; and the first film layer includes a first opening; and a light-emitting element on the drive substrate, where the light-emitting element is disposed corresponding to the first opening. The drive substrate further includes an auxiliary film layer; and the auxiliary film layer includes a thickened part, a thinned part, or a hollow part overlapped with the first opening.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority of Chinese Patent Application No. 202210911190.7, filed on Jul. 29, 2022, the content of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure generally relates to the field of display technology and, more particularly, relates to a display panel and a fabrication method thereof, and a display apparatus.

BACKGROUND

With continuous development of display technology, display panels have been widely used. However, the display panels in the existing technology still have certain technical problems that need to be solved urgently. For example, the reliability of the display panels needs to be improved.

SUMMARY

One aspect of the present disclosure provides a display panel. The display panel includes a substrate; a drive substrate on the substrate, where the drive substrate includes a first film layer; and the first film layer includes a first opening; and a light-emitting element on the drive substrate, where the light-emitting element is disposed corresponding to the first opening. The drive substrate further includes an auxiliary film layer; and the auxiliary film layer includes a thickened part, a thinned part, or a hollow part overlapped with the first opening.

Another aspect of the present disclosure provides a display apparatus including a display panel. The display panel includes a substrate; a drive substrate on the substrate, where the drive substrate includes a first film layer; and the first film layer includes a first opening; and a light-emitting element on the drive substrate, where the light-emitting element is disposed corresponding to the first opening. The drive substrate further includes an auxiliary film layer; and the auxiliary film layer includes a thickened part, a thinned part, or a hollow part overlapped with the first opening.

Another aspect of the present disclosure provides a fabrication method of a display apparatus. The method includes forming a first film layer of a drive substrate, where the first film layer includes a first opening; forming an auxiliary film layer, where the auxiliary film layer covers the first film layer and includes a hollow part overlapped with the first opening; forming a photoresist pattern, where the photoresist pattern is on a side of the auxiliary film layer away from the first film layer and includes a through hole overlapped with the first opening; forming an electrode layer, where the electrode layer includes a first electrode part and a second electrode part; the first electrode part covers the photoresist pattern; and the second electrode part includes a part in the first opening; removing the photoresist pattern and the first electrode part; providing a light-emitting element, and transporting the light-emitting element over the drive substrate, where the light-emitting element includes a main body part and a bonding electrode; and bonding the light-emitting element with the second electrode part, such that the bonding electrode and the second electrode part form an electrode of the light-emitting element.

Other aspects of the present disclosure may be understood by those skilled in the art in light of the description, the claims, and the drawings of the present disclosure.

DETAILED DESCRIPTION

In order to make above objectives, features and advantages of the present disclosure more clearly understood, the present disclosure is further described below with reference to the accompanying drawings and embodiments.

It should be noted that specific details are set forth in the following description in order to facilitate a thorough understanding of the present disclosure. However, the present disclosure may be implemented in various other ways different from those described herein, and those skilled in the art may make similar promotions without departing from the connotation of the present disclosure. Accordingly, the present disclosure is not limited by specific embodiments disclosed below.

The terms used in embodiments of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure. As used in embodiments of the present disclosure and the appended claims, the singular forms “a”, “said” and “the” are intended to include the plural forms as well, unless the context clearly dictates otherwise.

It should be noted that directional terms such as “up”, “down”, “left”, “right” described in embodiments of the present disclosure are described from the angles shown in the drawings and should not be understood as the limitation of the present disclosure. In addition, in the context, it also should be understood that when an element is referred to as being formed “on” or “under” another element, it may not only be directly formed “on” or “under” the other element, but also indirectly formed “on” or “under” another element through intermediate elements.

Furthermore, exemplary embodiments may be embodied in various forms and should not be understood as the limitation of embodiments set forth herein; rather, these embodiments are provided to make the present disclosure thorough and complete, and fully convey the concept of exemplary embodiments to those skilled in the art. Same reference numerals in the drawings denote same or similar structures, and thus their repeated descriptions are omitted. The terms expressing position and direction described in the present disclosure are all described by taking the accompanying drawings as an example, but changes may also be made as required, and the changes may all be included in the protection scope of the present disclosure. The drawings of the present disclosure are only used to illustrate relative positional relationship, and the layer thicknesses of some parts are drawn in an exaggerated manner to facilitate understanding. The layer thicknesses in the drawings may not represent proportional relationship of actual layer thicknesses. Also, embodiments of the present disclosure and the features of embodiments may be combined with each other without conflict. The drawings of various embodiments in the present disclosure use same reference numerals. In addition, similarities between various embodiments may not be repeated.

Referring toFIGS.1-2,FIG.1illustrates a top view of a display panel according to various embodiments of the present disclosure; andFIG.2illustrates an enlarged schematic of a local region of a display region inFIG.1.FIG.3illustrates a local cross-sectional view along a line AA′ inFIG.2.FIG.4illustrates another local cross-sectional view along a line AA′ inFIG.2.

Optionally, the display panel100may be divided into a display region AA and a non-display region NA surrounding the display region AA. It may be understood that the dotted box inFIG.1is used to indicate the boundary between the display region AA and the non-display region NA. The display region AA may be a region used by the display panel for displaying pictures, and normally may include a plurality of pixels sp arranged in an array. The pixel sp may include a light-emitting element (e.g., a diode) and a control element (e.g., a thin film transistor including a pixel drive circuit) which are corresponding to the pixel. The non-display region NA may surround the display region AA, and normally include peripheral drive elements, peripheral wirings, and a fan-out region.

Optionally, the display panel100may include a substrate210.

Optionally, the substrate210may be flexible or rigid. It should be noted that when a certain film layer is located “on” a certain reference film layer in embodiments of the present disclosure, it may be understood that the reference film layer is “on the side away from the substrate”; unless otherwise specified, “on” may only indicate a directional relationship and may not indicate that two film layers are necessarily adjacent or contacting film layers.

The drive substrate200may be on the side of the substrate210facing the display surface or the touch surface of the display panel100.

The drive substrate200may also include a drive circuit layer220, and the drive circuit layer220may be on the substrate210.FIG.4illustrates another local cross-sectional view along a line AA′ inFIG.2. In some optional embodiments,FIG.4may be used for describing the related structure of the drive circuit layer220inFIG.3.

Optionally, the drive circuit layer220may include structures such as thin film transistors TFT, capacitors C, wirings L, and the like.

In one embodiment, the film layers of the drive circuit layer220may include a buffer layer221, an active pattern222, a gate insulating layer223, a gate electrode224, an intermediate dielectric layer225, an interlayer dielectric layer226, a source electrode227s, a drain electrode227d, and a passivation layer228.

The buffer layer221may prevent impurities such as oxygen, moisture and the like from permeating from the substrate210and may planarize the substrate210. In addition, the buffer layer221may control the heat transport rate in the annealing process for the formation of the active pattern222. The buffer layer221may include a stacked structure including one or more inorganic materials such as silicon oxide, silicon nitride, silicon oxynitride, and the like.

The drive circuit layer220may include a plurality of thin film transistors TFT, and the thin film transistors may form a pixel circuit for light-emitting devices in the display layer.

A top-gate thin film transistor is taken as a structure example in embodiments of the present disclosure. The thin film transistor layer TFT may include the active pattern222on the substrate210. The active pattern222may include a silicon semiconductor or an oxide semiconductor.

The silicon semiconductor may include one or more of amorphous silicon, single crystal silicon, and polycrystalline silicon. Exemplarily, the active pattern222may include low temperature polycrystalline silicon.

When the active pattern222is made of a polycrystalline silicon material, the active pattern222may be formed by using a low temperature amorphous silicon technology, that is, an amorphous silicon material may be melted by the laser to form the polycrystalline silicon material. In addition, other manners such as rapid thermal annealing (RTA), solid phase crystallization (SPC), excimer laser annealing (ELA), metal induced crystallization (MIC), metal induced lateral crystallization (MILC), and/or continuous lateral solidification (SLS) may also be used.

The active pattern222may further include source and drain regions formed by doping N-type impurity ions or P-type impurity ions; and a channel region may be between the source and drain regions.

When the active pattern222includes an oxide semiconductor, the oxide semiconductor may include indium (In), zinc (Zn), gallium (Ga), tin (Sn), titanium (Ti), aluminum (Al), hafnium (Hf), Zirconium (Zr), Magnesium (Mg), and/or the like. The active pattern222may include binary compounds, ternary compounds or quaternary compounds. For example, the active pattern222may include indium gallium zinc oxide (IGZO), indium tin zinc oxide (ITZO), gallium zinc oxide (GaZnxOy), indium zinc oxide (IZO), zinc magnesium oxide (ZnMgxOy), zinc oxide (ZnOx), gallium oxide (GaOx), tin oxide (SnOx), indium oxide (InOx), indium gallium hafnium oxide (IGHO), tin aluminum zinc oxide (TAZO), indium gallium tin oxide (IGTO), and/or the like. Above-mentioned materials may be used alone or also be used in combination with each other. In exemplary implementation manners of the present disclosure, above-mentioned oxide semiconductor may be doped with lithium (Li), sodium (Na), manganese (Mn), nickel (Ni), palladium (Pd), copper (Cu), carbon (C), nitrogen (N), phosphorus (P), titanium (Ti), zirconium (Zr), vanadium (V), ruthenium (Ru), germanium (Ge), tin (Sn), fluorine (F), and/or the like.

Optionally, the gate insulating layer223may be on the active pattern222. The gate insulating layer223may include an inorganic layer such as silicon oxide or silicon nitride and may be a single layer or multiple layers.

Optionally, the gate electrode224may be on the gate insulating layer223. The gate electrode224may a single layer or multiple layers including gold (Au), silver (Ag), copper (Cu), nickel (Ni), platinum (Pt), palladium (Pd), aluminum (Al), molybdenum (MO), or chromium (Cr), or may be an alloy such as an aluminum (Al): neodymium (Nd) alloy and a molybdenum (MO): tungsten (W) alloy.

The intermediate dielectric layer225may cover the gate electrode224and be disposed on the gate insulating layer223. The intermediate dielectric layer225may include a stacked structure including one or more inorganic materials such as silicon oxide, silicon nitride, silicon oxynitride and the like. Exemplarily, the intermediate dielectric layer225may include silicon nitride.

The interlayer dielectric layer226may be disposed on the intermediate dielectric layer225. The interlayer dielectric layer226may include a stacked structure including one or more inorganic materials such as silicon oxide, silicon nitride, silicon oxynitride and the like.

The source electrode227smay be in contact with the source region222sof the active pattern222, and the drain electrode227dmay be in contact with the drain region222dof the active pattern222. The source electrode227sand the drain electrode227dmay be formed in a same process; and both the source electrode227sand the drain electrode227dmay be in a same film layer. In one embodiment, the first contact hole CH1exposing a part of the source region222sand the second contact hole CH2exposing a part of the drain region222dmay be formed through the gate insulating layer223, the intermediate dielectric layer225and the interlayer dielectric layer226, respectively. The source electrode227smay in contact with the upper surface of the source region222sthrough the first contact hole CH1, and the drain electrode227dmay in contact with the upper surface of the drain region222dthrough the second contact hole CH2. The source electrode227sand the drain electrode227dmay be made of metals such as aluminum (Al), silver (Ag), chromium (Cr), titanium (Ti), tantalum (Ta), molybdenum (Mo) and the like, alloys thereof, nitrides thereof, conductive metal oxides, transparent conductive materials, and/or the like. In one embodiment, the source electrode227sand the drain electrode227dmay include a Ti/Ai/Ti metal stacked structure.

The passivation layer228may cover the source electrode227sand the drain electrode227dand may be disposed on the interlayer dielectric layer226. The passivation layer228may include a stacked structure including one or more inorganic materials such as silicon oxide, silicon nitride, silicon oxynitride and the like. In one embodiment, the passivation layer228may include silicon nitride.

The capacitor C may include the first electrode plate CP1and the second electrode plate CP2which are opposite with each other. The capacitor C may be used to maintain the node potential in the drive circuit. The first electrode plate CP1may be between the gate insulating layer223and the intermediate dielectric layer225. The first electrode plate CP1may be in a same film layer as the gate electrode224and formed of a same material as the gate electrode224. The second plate CP2may be between the intermediate dielectric layer225and the interlayer dielectric layer226. The second plate CP2may be made of a material including metals such as aluminum (Al), silver (Ag), chromium (Cr), titanium (Ti), tantalum (Ta) and molybdenum (Mo), alloys thereof, nitrides thereof, conductive metal oxides, transparent conductive materials, and the like. In one embodiment, the second plate CP2may include molybdenum (Mo).

The wiring L may be used to provide various signals. InFIG.4, the wiring L may be between the interlayer dielectric layer226and the passivation layer228as an example. The wiring L may be in a same film layer as the source electrode227sand the drain electrode227dand made of a same material as the source electrode227sand the drain electrode227d. According to the types and requirements of the signals transmitted by the wiring L, the wiring L may be in another film layer or multiple film layers. For example, the wiring L and the gate electrode224may be in a same film layer, or the wiring L and the second plate CP2may be in a same film layer, and so on.

It may be understood that the drive circuit layer220may include a drive circuit; and the drive circuit may be used to drive a light-emitting element300to emit light. In one embodiment, the drive circuit may include a pixel circuit; and the pixel circuit may be electrically connected to the light-emitting element300for drive the light-emitting element300to emit light.

Referring toFIGS.3-4, the drive substrate200may further include the planarization layer230. The planarization layer230may be on the drive circuit layer220and used to form a flat surface on the drive circuit layer220. In one embodiment, the planarization layer230may be on the passivation layer228; and a side of the planarization layer230away from the passivation layer228may have a substantially flat upper surface. The planarization layer230may include an organic material such as photoresist, polyacrylate-based resin, polyimide-based resin, polyamide-based resin, siloxane-based resin, acrylic-based resin, epoxy-based resin, and/or the like.

Optionally, in some embodiments, the planarization layer230may include at least two layers; and other conductive layers or other metal layers may be disposed between two planarization layers230to play a transition role or a bridge role for electrically connection the thin film transistor TFT and the light-emitting element300.

The drive circuit layer220may be formed by a film stacking manner. In the drive circuit layer220, patterns of the thin film transistor TFT including the active pattern222, the gate electrode224, the source electrode227sand the drain electrode227dand other patterns such as the capacitor C and the wiring L may make the upper surface of the drive circuit layer220uneven. In addition, the through holes (such as the first contact hole CH1, the second contact hole CH2and the like) passing through the film layer may also bring the problem of unevenness on the upper surface of the drive circuit layer220. The upper surface of the drive circuit layer220may be the upper surface of the passivation layer228. By disposing the planarization layer230, a flat surface may be provided for the components to be formed subsequently.

It should be noted that, in some optional embodiments of the present disclosure, the auxiliary film layer280may reuse the planarization layer230.

Referring toFIG.4, the drive substrate200may further include a connection part240. The connection part240may be disposed on the planarization layer230. The connection part240may include the first connection part241and the second connection part242. The first connection part241may be electrically connected to the thin film transistor TFT in the drive circuit layer220, and the second connection part242may be electrically connected to the power line. In one embodiment, the first connection part241may be electrically connected to the drain electrode227dof the thin film transistor TFT through the contact hole CH. The contact hole CH may pass through the planarization layer230and the passivation layer228and may expose a part of the drain electrode227dof the thin film transistor TFT. The connection part240may be made of metals such as aluminum (Al), silver (Ag), chromium (Cr), titanium (Ti), tantalum (Ta), molybdenum (Mo) and the like, and include alloys thereof, nitrides thereof, conductive metal oxides, transparent conductive materials, and/or the like. In one embodiment, the connection part240may include a Ti/Ai/Ti metal stack structure. The material of the connection part240may be same as the materials of the source electrode227sand the drain electrode227d.

In order to fully utilize the metal film layer, the metal film layer where the connection part240is located may also include other metal components, such as power lines, signal lines, electrical blocking components, light-blocking components, and/or the like.

Optionally, the drive substrate200may further include the first film layer250; and the first film layer250may include the first opening OP1. As shown inFIGS.3and4, the first film layer250of the drive substrate200may be on the side of the drive circuit layer220away from the substrate210, that is, the drive circuit layer220may be between the first film layer250and the substrate210. The planarization layer230may be between the first film layer250and the drive circuit layer220. The connection part240may be between the planarization layer230and the first film layer250.

Optionally, the display panel100may further include the light-emitting element300on the drive substrate200; and the light-emitting element may be disposed corresponding to the first opening OP1.

That is, the first opening OP1may define the light-emitting element300, and the light-emitting element300may be at least partially in the first opening OP1. In other words, along the first direction X, the first film layer250may be at least partially between two adjacent light-emitting elements300, where the first direction X is a direction in parallel with the plane of the display panel100.

Optionally, the light-emitting element300may be a light-emitting diode, for example, an inorganic light-emitting diode. The size of the light-emitting element300may be less than 200 microns. In one embodiment, the size of the light-emitting element300may be less than 100 microns, 50 microns, or the like.

FIG.6illustrates an enlarged schematic of a local region of a light-emitting element and a local region of display panel according to various embodiments of the present disclosure; andFIG.7illustrates another enlarged schematic of a local region of a light-emitting element and a local region of display panel according to various embodiments of the present disclosure. Only some film layers in the drive substrate200are illustrated inFIGS.6and7.

The light-emitting element300may include a main body part310and a connection electrode320. The main body part310may include an N-type semiconductor layer311, a P-type semiconductor layer312, and an active layer313therebetween.

The main body part310of the light-emitting element300may be understood as a part of the light-emitting element300other than the connection electrode320.

The material of the main body part310of the light-emitting element300may include, but may not be limited to, compound semiconductors such as gallium nitride (GaN), aluminum indium gallium phosphide (AlInGaP), aluminum gallium arsenide (AlGaAs); and/or gallium arsenide phosphide (GaAsP).

The connection electrode320may include the first electrode321and the second electrode322. The first electrode321may be electrically connected to the P-type semiconductor layer312, the second electrode322may be electrically connected to the N-type semiconductor layer311, the first electrode321may be a positive electrode, and the second electrode322may be a negative electrode.

The connection electrode320may be made of a material including an alloy or solid solution of metals such as gold (Au), tin (Sn), nickel (Ni), titanium (Ti), aluminum (Al), silver (Ag), and indium (In). In one embodiment, the connection electrode320may include a gold-indium alloy.

The first electrode321and the second electrode322may both be on a same side of the main body part310. For example, the first electrode321and the second electrode322may be both on the side of the N-type semiconductor layer311adjacent to the P-type semiconductor layer312. In the film layer structure of the display panel, both the first electrode321and the second electrode322may be on the side of the main body part310facing the drive substrate200. When transporting the light-emitting element300to the drive substrate200, it is convenient to realize the electrical connection between the light-emitting element300and the drive substrate200by a thermocompression manner. For example, the bonding between the light-emitting element300and the drive substrate200may be realized by a eutectic manner.

The main body part310may further include an insulating layer314. The insulating layer314may cover the N-type semiconductor layer311, the P-type semiconductor layer312and the active layer313in the main body part. Through holes may be formed in the insulating layer314to expose a part of the N-type semiconductor layer311and a part of the P-type semiconductor layer312, respectively. At the through holes of the insulating layer314, the first electrode321may be electrically connected to the P-type semiconductor layer312, and the second electrode322may be electrically connected to the N-type semiconductor layer311.

The main body part310may further include a Bragg reflection layer. The Bragg reflection layer may be on the side of the P-type semiconductor layer312away from the N-type semiconductor layer311to improve the light extraction efficiency of the light-emitting element300by reflecting light.

As shown inFIG.7, the main body part310of the light-emitting element300may further include a transparent electrode315. The transparent electrode315may be between the first electrode321and the P-type semiconductor layer312. The material of the transparent electrode315may be indium tin oxide (ITO), which may be used to adjust the current density distribution in different regions of the light-emitting element300.

As shown inFIG.7, the upper surface of the light-emitting element300may be provided with micro-patterns. For example, rough patterns may be provided on the upper surface of the N-type semiconductor layer311to improve the light extraction efficiency of the light-emitting element300.

Referring toFIGS.3-4and6-7, optionally, the first opening OP1of the first film layer250may expose the connection part240; the connection electrode320of the light-emitting element300may include the first part320ain the first opening OP1; the connection electrode320of the light-emitting element300may be in contact with and electrically connected to the connection part240; and the first part320aof the connection electrode320of the light-emitting element300may be in contact with and electrically connected to the connection part240.

Optionally, the connection electrode320may fill the first opening OP1of the first film layer250. The first part320aof the connection electrode320may fill the first opening OP1of the first film layer250. For example, the lower surface320bof the connection electrode320may be in contact with the connection part240.

The upper surface of the connection part240may be roughened to increase the adhesion between the connection part240and the first part320aof the connection electrode320.

The thickness of the first film layer250may be adjusted to improve the reliability between the light-emitting element300and the drive substrate200.

The connection electrode320may further include the second part320cbetween the first part320aand the main body part310of the light-emitting element300.1

FIGS.6and7illustrate the first part320aand the second part320cof the first electrode321. The first part320aand the second part320cof the second electrode322may be divided in a same manner. That is, the second electrode322may include the first part320ain the first opening OP1of the first film layer250and the second part320cbetween the first part320aand the main body part310of the light-emitting element300.

In the existing technology, the electrode of the light-emitting element may be directly disposed on the metal connection electrode; one end of the metal connection electrode may be connected to a lower thin film transistor through a via in the film layer between the metal connection electrode and the thin film transistor; and the electrode of the light-emitting element may be at the other end of the metal connection electrode. In order to avoid that the position of disposing the via affects the bonding process of the light-emitting element due to the uneven surface caused by the metal connection electrode, a certain distance may need to be reserved between the end of the metal connection electrode at the position of the via and the end of the electrode where the light-emitting element is disposed. Therefore, the length of the metal connection electrode may be long, and the metal connection electrode may increase the reflectivity of the display panel and affect the display effect. In the present disclosure, by disposing the connection electrode320of the light-emitting element300at the first opening OP1of the first film layer250, the reflectivity of the display panel may be reduced, and the display effect of the display panel may be improved.

In embodiments of the present disclosure, the shape of the first opening OP1of the first film layer250may be a rectangle as an example. The shape of the first opening OP1of the first film layer250may also include other suitable shapes such as a circle.

Optionally, in some embodiments of the present disclosure, as shown inFIG.4, the first electrode321of the light-emitting element300may be electrically connected to the first connection part241and may be electrically connected to the drain electrode227dof the thin film transistor TFT through the first connection part241. The first connection part241may be connected to the thin film transistor TFT through the contact hole CH passing through the planarization layer230and the passivation layer228. The part of the first connection part241located in the contact hole CH may not have a flat surface, and the part of the first connection part241exposed by the first opening OP1of the first film layer250may need to have a relatively flat surface, which may be beneficial for bonding of the light-emitting element300. Along the direction perpendicular to the plane of the display panel100, the contact hole CH may not be overlapped with the first opening OP1of the first film layer250, which may avoid the influence of the contact hole CH on the flat part of the first connection part241. The distance between the part of the first connection part241in the contact hole CH and the part of the first connection part241exposed by the first opening OP1may be configured as requirements.

Referring to related drawings of the present disclosure, optionally, the second electrode322of the light-emitting element300may be electrically connected to the second connection part242and may also be connected to the power line through the second connection part242.

Optionally, the first film layer250may include an organic material. Optionally, the first film layer250may be an organic layer. For example, the first film layer250may include photoresist, polyacrylate-based resin, polyimide-based resin, polyamide-based resin, siloxane-based resin, acrylic-based resin, epoxy-based resin, and the like. Through such design, on the one hand, the first opening OP1with a certain depth may be provided to reduce the thickness requirement of the photoresist layer for subsequent patterning of relevant film layers (the photoresist layer mentioned here is described below), thereby reducing process difficulty; on the other hand, the organic first film layer250may continue to provide a flat surface above the connection part240, which may be beneficial for smooth eutectic process between the second electrode part520and a bonding electrode330(the process refers to following drawings related to above-mentioned structure and is also described below), thereby improving electrode bonding reliability.

Optionally, referring toFIG.8,FIG.8illustrates another local cross-sectional view along a line AA′ inFIG.2; and the cross section is perpendicular to the plane where the display panel is located.

The first film layer250may include a negative photoresist. The inventors had found that, for the first film layer250formed by using the negative photoresist, during the exposure process, the exposure amount at different thickness positions may be different along the thickness direction. The farther away from the exposure source is, the smaller the exposure is. During the development process, the position where the exposure amount is insufficient may also be easily removed, so that inclined sidewalls may be formed in the first opening OP1of the first film layer250.

Optionally, the first film layer250may be provided with the first opening OP1, and along the direction from the first film layer250to the light-emitting element300, the sidewall OPW of the first opening OP1may be inclined toward the inside of the first opening OP1. That is, the area of the top surface of the first opening OP1(adjacent to the main body part310of the light-emitting element300) may be smaller than the area of the bottom surface of the first opening OP1(adjacent to the connection part240).

The connection electrode320of the light-emitting element300may include the first part320afilling the first opening OP1, which may cooperate with the inclined configuration of the sidewall OPW of the first opening OP1. Therefore, the ability of the drive substrate200to fix the light-emitting element300may be improved, and the occurrence probability of the light-emitting element300falling off from the drive substrate200may be reduced.

Moreover, in some optional processes, the material of the photoresist layer for subsequent patterning of relevant film layers may also be a negative photoresist. In the case where the photoresist layers of the first film layer250and subsequent patterning related film layers are all made of a negative photoresist, a mask (such as a same mask) having a same pattern of the light-blocking region may be used to form the first film layer250and related photoresist pattern, which may save the cost of mask production.

Referring to any cross-sectional views in the present disclosure, optionally, the first film layer250may include a light-absorbing material. The first film layer250may be used for blocking light and reduce the reflectivity of the display panel by absorbing external ambient light. For example, the first film layer250may include black pigment, that is, the first film layer250may be a black layer. In one embodiment, the first film layer250may be black photoresist.

Optionally, all other parts of the first film layer250may block light except the position where the opening (e.g., the first openings OP1) is disposed. It may be understood that, in some other optional embodiments of the present disclosure, the first film layer may further include other openings as required, such as the second opening OP2described below; and the position corresponding to the second opening OP2may also be excluded.

Through one embodiment, on the one hand, the first film layer250may greatly reduce the problem of high reflectivity of the display panel caused by the metal components in the drive circuit layer220; on another hand, the first film layer250may also reduce the influence of the external ambient light on the performance of the elements in the drive circuit layer220, for example, avoid the problem that the external ambient light is incident on the thin film transistor and causes the thin film transistor TFT to generate light leakage; and on another hand, the first film layer250may absorb the light emitted from the light-emitting element300downward (i.e., toward the substrate210), thereby preventing such light from being reflected by other components toward the display surface side of the display panel to affect the display effect.

It should be noted that, in some optional embodiments of the present disclosure, above-mentioned embodiments may be combined. For example, the first film layer250may be a negative photoresist and also include a light-absorbing material. In other words, the first film layer may be an organic material, and/or the first film layer may be a negative material, and/or the first film layer may include a light-absorbing material. The following non-contradictory embodiments after combination still belong to the solutions described in present disclosure, which may not be described in detail in the present disclosure.

Referring to the drawings related to the cross-sections of the display panel and corresponding top views of the cross-sectional views in the present disclosure, the drive substrate200may further include the auxiliary film layer280. The auxiliary film layer280may be on one side of the first film layer250along the third direction Z, where the third direction Z is a direction perpendicular to the plane where the display panel100is located.

Optionally, the auxiliary film layer280may include a part overlapped with the first film layer250, but the auxiliary film layer280may have a structural change at the first opening OP1of the first film layer250. The structural change mentioned here refers to the film thickness change of the auxiliary film layer280along the third direction Z. It should also be noted that the thickness mentioned here includes the case where the thickness is zero. In other words, the auxiliary film layer280may include a first part overlapped with the first film layer250, and further include a second part overlapped with the first opening OP1of the first film layer250. There may be a level difference between the first part and the second part.

It should be noted that the “overlap” of two structures described in one embodiment may be understood as the “overlap” of the orthographic projections of two structures on the substrate210(i.e., the orthographic projections along the third direction Z).

Through embodiments of the present disclosure, a thickness difference may be between the first opening and the non-first opening corresponding to the auxiliary film layer, so that the drive substrate at the first opening may be more easily bonded with the light-emitting element than the region of the non-first opening in terms of film structure. Therefore, through the auxiliary film layer provided in one embodiment, the reliability of aligning and bonding of the light-emitting element and the drive substrate at the first opening may be improved, which may be more convenient and stable to align and bond the light-emitting element corresponding to the first opening and the drive substrate.

Optionally, the auxiliary film layer280may be adjacent to the first film layer250. Optionally, the auxiliary film layer280may be in contact with the first film layer250. In such way, the structural change of the auxiliary film layer280may be more directly reflected in the first opening OP1of the first film layer250, which may desirably assist and enhance aligning and bonding the light-emitting element and the drive substrate and improve the bonding stability.

Optionally, the auxiliary film layer280may include a thickened part, and/or a thinned part, and/or a hollow part overlapped with the first opening OP1.

Optionally, the auxiliary film layer280having a thinned part or a hollow part corresponding to the first opening OP1is shown inFIG.3orFIG.5, whereFIG.5illustrates another local cross-sectional view along a line AA′ inFIG.2, and the cross section is perpendicular to the plane where the display panel is located. Optionally, the auxiliary film layer280may include a hollow part281-aoverlapped with the first opening OP1as shown inFIG.4; and the auxiliary film layer280may also include a thinned part282-boverlapped with the first opening OP1as shown inFIG.5. The thickness of the auxiliary film layer280at the thinned part or the hollow part may be lost to compensate for the depth of the first opening, which may better guide the light-emitting element to be aligned, better limit the light-emitting element after the alignment and improve alignment stability of the light-emitting element and the drive substrate.

Optionally, when the auxiliary film layer280has a thickened part corresponding to the first opening OP1, the light-emitting element may be raised by the thickened part to improve alignment convenience, which may be described in detail below.

As shown inFIG.3,5or27, the auxiliary film layer280may include the first auxiliary layer281on the side of the first film layer250away from the substrate210; and/or, the auxiliary film layer280may include the second auxiliary layer282on the side of the first film layer250facing the substrate210.

Optionally, as shown inFIG.5, the auxiliary film layer280may include the second auxiliary layer282on the side of the first film layer250facing the substrate210. Optionally, the second auxiliary layer282may reuse above-mentioned planarization layer230.

Optionally, the second auxiliary layer282may include a plurality of sub-layers, for example, the first sub-layer2821and the second sub-layer2822stacked in sequence along the direction of the substrate210toward the first film layer250.

Optionally, the second auxiliary layer282may include the thinned part282-b. For example, the thinned part282-bof the second auxiliary layer282may be formed by a groove with an opening facing the light-emitting element300.

Optionally, when the second auxiliary layer282includes a plurality of sublayers, the groove may be formed at least in an outer sublayer on the side of the second auxiliary layer282facing the light-emitting element, for example, in the second sublayer2822inFIG.5. The groove may be a groove that does not pass through the second auxiliary layer282or the second sub-layer2822or may be a groove that passes through the second auxiliary layer282or may be a groove that passes through the second sublayer2822and extends to other sublayers, such as a groove that extends to the first sublayer2821and does not pass through the second auxiliary layer282.

Optionally, the thinned part282-bof the second auxiliary layer282may include a groove with an opening facing the light-emitting element300; and the thinned part282-bof the second auxiliary layer282may be formed by etching when the connection part240is patterned to form the patterns of the first connection part241and the second connection part242.

Optionally, when the connection part240is patterned to form the patterns of the first connection part241and the second connection part242, the region between the first connection part241and the second connection part242that are electrically connected to a same light-emitting element300correspondingly may be over-etched, and the thinned part282-bof the second auxiliary layer282may also be formed.

In some optional embodiments of the present disclosure, the auxiliary film layer may include both the first auxiliary film layer and the second auxiliary layer, and the two layers may cooperate and complement with each other, thereby further improving the reliability of the display panel. Some optional examples may also be illustrated in the present disclosure.

Optionally, referring toFIGS.3-4, the auxiliary film layer280may include the first auxiliary film layer281on the side of the first film layer250away from the substrate210.

Through such design, the first auxiliary layer281may have a sufficient thickness to perform differentiated design in the region that needs to be hollowed or needs to be changed. Moreover, the reliability of the film layer may be improved, and the fabrication process may be simplified.

The fabrication method of the display panel provided by the present disclosure is described hereinafter.

FIG.9illustrates a flowchart of a fabrication method of a display panel according to various embodiments of the present disclosure.

The following describes the fabrication method of the display panel provided by embodiments of the present disclosure with reference toFIGS.9to21.

FIG.10illustrates a local top view of a drive substrate according to various embodiments of the present disclosure.FIG.11illustrates a local cross-sectional view along a line BB′ inFIG.10.FIG.12illustrates another local cross-sectional view along a line BB′ inFIG.10.FIGS.11and12respectively illustrate two examples of drive substrates. Subsequent process steps are described using the drive substrate inFIG.12as an example. It should be noted that subsequent process steps are also applicable to the drive substrate shown inFIG.11.

First, in S101, the first film layer250of the drive substrate200may be formed, and the first opening OP1may be formed in the first film layer250.

As shown inFIGS.11and12, the drive substrate200may include the substrate210, a wire layer260, an insulating layer270, the connection part240and the first film layer250.

The wire layer260may be located on the substrate210and may include a plurality of signal lines for transmitting drive signals.FIG.11takes the drive substrate200including one wire layer260as an example. In other embodiments, the circuit layer250may include multiple layers to meet the requirements of the number and location of signal lines.

The insulating layer270may cover the wire layer260.

The connection part240may be disposed on the insulating layer270and electrically connected to the wire layer260through the contact hole CH disposed in the insulating layer270.

The first film layer250may be on the upper side of the drive substrate200. The first opening OP1may be formed in the first film layer250. The first opening OP1may expose the connection part240and may be used to receive a part of the electrode layer formed subsequently.

As shown inFIGS.11and12, the drive substrate200may include the substrate21, the drive circuit layer220, the planarization layer230and the first film layer250. For the drive substrate200inFIG.12, reference may be made to the drive substrate200inFIG.4and its related description, and same parts may not be described in detail.

The first opening OP1of the first film layer250may be used to receive a part of the electrode layer formed subsequently.

It should be noted that, in order to illustrate the structures closely related to each step more clearly, some reference numerals may be omitted in relevant drawings of subsequent process steps, and reference may be made to other relevant drawings in present disclosure for the omitted reference numerals.

At S102, the auxiliary film layer280may be formed. The auxiliary film layer280may cover the first film layer250and include the hollow part281-aoverlapped with the first opening OP1.

FIG.13illustrates a cross-sectional view of a display panel in another fabrication process along a line BB′ inFIG.10.

Optionally, the auxiliary film layer280may be the first auxiliary layer281. Regarding the auxiliary film layer in one embodiment, in case that there is no conflict, reference may be made to the description of the first auxiliary layer281in other embodiments of the present disclosure, which may not be described in detail herein.

Optionally, the first film layer250may be provided with the first opening OP1; the auxiliary film layer280(i.e., the first auxiliary layer281) may be provided with the hollow part281-a; and the first opening OP1and the hollow part281-amay be overlapped with each other.

Optionally, the connection electrode320may include a part disposed in the first opening OP1and the hollow part281-a.

Optionally, the auxiliary film layer280may cover the upper surface of the first film layer250and the sidewall of the first opening OP1of the first film layer250, that is, the auxiliary film layer280may surround the exposed surface of the first film layer250.

Optionally, the part of the connection electrode320of the light-emitting element300in the first opening OP1may be in contact with the auxiliary film layer280.

FIG.14illustrates a local top view after forming a photoresist layer on a drive substrate; andFIG.15illustrates a cross-sectional view along a line CC′ inFIG.14.

At S103, a photoresist pattern410may be formed. The photoresist pattern410may be on the side of the auxiliary film layer280away from the first film layer250and have a through hole420overlapped with the first opening OP1.

Optionally, the photoresist pattern410may be formed. The photoresist layer400may be on one side of the first film layer250.

Optionally, the photoresist layer400may be provided first. The photoresist layer400may be disposed on the upper surface of the drive substrate200as an entire layer. For example, the photoresist layer400may be disposed on the first film layer250; and the photoresist layer400may be in contact with the first film layer250and fill the first opening OP1of the first film layer250.

The photoresist pattern410may be formed. The photoresist pattern410may have the through hole420overlapped with the first opening OP1.

FIG.16illustrates a structural schematic of patterning a photoresist layer to form a photoresist pattern.

Optionally, the photoresist layer400may be patterned by exposure and development to form the photoresist pattern410.

For example, a mask may be placed above the photoresist layer400, and light may selectively expose the photoresist layer400through the mask, so that the exposed region of the photoresist layer400may become a soluble substance; or the exposed region of the photoresist layer400may be changed into an insoluble substance, and the soluble substance in the photoresist layer400may be removed by developing to form the photoresist pattern410.

The material of the photoresist layer400may be a negative photoresist, the exposed region of the photoresist layer400may become insoluble and may be retained in the developing process, while the non-exposed region of the photoresist layer400part may be removed.

FIG.17illustrates a structural schematic after forming an electrode layer.

At S104, an electrode layer500may be formed. The electrode layer500may include the first electrode part510and the second electrode part520; the first electrode part510may cover the photoresist pattern410; and the second electrode part520may include a part in the first opening OP1and the hollow part281-a.

The electrode layer500may be formed on the photoresist pattern410by an evaporation or physical vapor deposition manner. The electrode layer500may include the first electrode part510and the second electrode part520. The first electrode part510may cover the photoresist pattern410(i.e., the remaining part of the photoresist layer400during development), and the second electrode part520may include a part in the first opening OP1of the first film layer250.

Since the photoresist pattern410has the through hole420, and the through hole420is overlapped with the first opening OP1of the first film layer250, when the electrode layer500is formed by a vapor deposition or physical vapor deposition manner, the electrode layer500may not only include the part on the photoresist pattern410, but also include the part in the first opening OP1of the first film layer250. In addition, by using a negative photoresist for the photoresist layer400, a sidewall inclined toward the center of the through hole420may be formed at the through hole420of the photoresist pattern410, such that the second electrode part520and the first electrode part510of the electrode layer500may be easily disconnected at the through hole420.

FIG.18illustrates a structural schematic after removing a photoresist pattern.

At S105, the photoresist pattern410and the first electrode part510may be removed.

Optionally, the second electrode part520may include a part in the first opening OP1of the first film layer250. The thickness of the second electrode part520may be greater than the depth of the first opening OP1. That is, the second electrode part520may further include a part protruding from the upper surface of the first film layer250.

Optionally, the second electrode part520may include a part in the hollow part281-a. The second electrode part520may further include a part protruding from the hollow part281-a, or in other words, the second electrode part520may further include a part protruding from the upper surface of the first auxiliary film layer281.

After removing the photoresist pattern410and the first electrode part510on the photoresist pattern410in the structure shown inFIG.17, the structure shown inFIG.18may be obtained.

The photoresist pattern410and the first electrode part510may be removed using a removal solution. The sidewall410of the photoresist pattern410is inclined, so that a gap may be between the sidewall410and the second electrode part520, which may facilitate the inflow of the removal solution (as shown by the dashed arrow inFIG.17). Therefore, the photoresist pattern410and the first electrode part510thereon may be removed smoothly.

FIG.19illustrates a schematic of transporting a light-emitting element.

At S106, the light-emitting element300amay be provided, and the light-emitting element300amay be transported to the top of the drive substrate200, where the light-emitting element300amay include a main body part310and a bonding electrode330.

A transport device600may transport the light-emitting element300aabove the drive substrate200. The light-emitting element300amay be additionally formed by processes such as epitaxial growth on the source substrate, patterning and the like, and may be placed above the drive substrate200by a transport manner.

The light-emitting element300amay include the main body part310and the bonding electrode330. The structure of the main body part310may be referred toFIGS.6-7and related descriptions, and also be referred toFIG.19; and same parts may not be described in detail.

The bonding electrode330may include the first bonding electrode331and the second bonding electrode332. The first bonding electrode331may be electrically connected to the P-type semiconductor layer312, and the second bonding electrode332may be electrically connected to the N-type semiconductor layer311.

The bonding electrode330may include a single-layer metal layer such as gold (Au) and indium (In), or a multi-layer metal layer stacked structure. In one embodiment, the bonding electrode330may include an indium (In) film layer.

The transport device600may include a transport head, a transport substrate, and the like. In one embodiment, the transport device600may be a stamp, and the stamp may pick up a plurality of light-emitting elements300athrough van der Waals force and release the light-emitting elements300at specific positions to complete the transport of the light-emitting elements300a.

FIG.20illustrates a structural schematic of a bonding process of a light-emitting element and a drive substrate.

At S107, the light-emitting element300amay be bonded with the second electrode part520, so that the bonding electrode330and the second electrode part520may form the connection electrode320of the light-emitting element300.

The bonding electrode330of the light-emitting element300amay be in contact with the second electrode part520on the drive substrate200, and a eutectic reaction may occur at a certain temperature. The bonding electrode330and the second electrode part520may be crystallized into a crystal mixture (eutectic), that is, the connection electrode320(the first electrode321and the second electrode322) of the light-emitting element300inFIG.20may be formed. In one embodiment, the second electrode part520may include gold (Au), the bonding electrode330may include indium (In), and the connection electrode320of the light-emitting element300formed by the eutectic reaction between the second electrode part520and the bonding electrode330may be a gold indium alloy.

During the bonding process, the second electrode part520may be melted and pressed, which may easily cause flow. By disposing the second electrode part520in the first opening OP1, the range of its flow to the surroundings may be reduced, so that the first electrode321and the second electrode322which are formed may be not in contact with each other to be short-circuited.

Another embodiment of the fabrication method of the display panel provided by embodiments of the present disclosure is described with reference toFIGS.9and21.FIG.21illustrates another schematic of transporting a light-emitting element.

S101-S103and S105may be same as described above, and the processes of S104, S106and S107are described as follows.

At S104, the electrode layer500may be formed. The electrode layer500may include the first electrode part510and the second electrode part520; the first electrode part510may cover the photoresist pattern410; and the second electrode part520may include a part in the first opening OP1.

In S104, the electrode layer500may include the first metal and the second metal which are stacked with each other. For example, the first metal may be gold (Au), and the second metal may be indium (In).

At S106, the light-emitting element300bmay be provided. The light-emitting element300bmay be transported to the top of the drive substrate200, where the light-emitting element300bmay include the main body part310.

At S107, the light-emitting element300bmay be bonded with the second electrode part520, so that the second electrode part520may form the connection electrode320of the light-emitting element300.

In S107, the first metal and the second metal, which are stacked with each other, in the second electrode part520may undergo eutectic reaction to form a gold-indium alloy, which may be used as the connection electrode320of the light-emitting element300. Meanwhile, during the bonding process, the main body part310of the light-emitting element300bmay also be in contact with the second electrode part520and form a fixed electrical connection.

The inventors had found that during the process of removing the photoresist pattern410and the first electrode part510by using the removal solution, the removal solution may also flow into the gap between the sidewall of the photoresist pattern410and the second electrode part520.

If the structure of the first auxiliary layer281is not provided, the first film layer250may be exposed at the gap, and the removal solution may be in contact with the first film layer250at the gap, which may result in that the black photoresist including the first film layer250is discolored to be failed.

The first auxiliary layer281may be provided. The first auxiliary layer281may cover the exposed surface of the first film layer250to isolate the first film layer250from the removal solution. In such way, when removing the photoresist pattern410, the removal solution may be prevented from contacting with the first film layer250and being corroded by the removal solution, thereby preventing the first film layer250from discoloration and failure.

Optionally, the first auxiliary layer281may be made of a material that is resistant to the influence of the removal solution.

Optionally, the density of the first auxiliary layer281may be higher than the density of the first film layer. For example, the first auxiliary layer281may be made of a molecular-level film material. Through such design, the ability of the first auxiliary layer281to protect the first film layer against the influence of the removal solution may be improved.

Optionally, the first auxiliary layer281may be overlapped with at least a part of the sidewalls of the first opening OP1.

It may be understood that the “overlapped” direction mentioned in one embodiment is a direction perpendicular to the plane where the sidewall of the first opening OP1is located. Optionally, the auxiliary film layer280may cover the upper surface of the first film layer250and the sidewall of the first opening OP1of the first film layer250, that is, the auxiliary film layer280may surround the exposed surface of the first film layer250. That is, the first auxiliary layer281may cover the sidewall of the first opening OP1. In one embodiment, the effect of the first auxiliary layer281in preventing the removal solution from invading the first film layer250may be further improved.

Optionally, as shown inFIG.10, the first auxiliary layer281may include the hollow part281-a; and the hollow part281-amay be within the coverage range of the first opening OP1. Optionally, the part of the connection electrode320of the light-emitting element300in the first opening OP1may be in contact with the auxiliary film layer280. That is, the first auxiliary layer281may be in contact with the film layer on the side of the exposed first film layer250, exposed by the first opening OP1, away from the first auxiliary layer281, such that the first film layer250may be encapsulated by the film layers on adjacent two sides of the first film layer250at the first opening OP1. In such way, the effect of the first auxiliary layer281in preventing the removal solution from invading the first film layer250may be further improved.

Optionally, in some embodiments, the first auxiliary layer may be a positive photoresist.

Optionally, the first auxiliary layer281may include an organic material.

On one hand, optionally, the first auxiliary layer281may include an organic material such as acrylic, polyimide (PI) or benzocyclobutene (BCB); the first auxiliary layer281may have a planarization function, which may continue to provide a flat surface on the first film layer to facilitate subsequent processes. For example, in some embodiments, the eutectic process between the second electrode part and the bonding electrode may be facilitated to proceed smoothly, and the reliability of electrode bonding may be improved.

On the other hand, as shown inFIG.22,FIG.22illustrates another cross-sectional view along a line AA′ inFIG.2; and the cross-section is perpendicular to the plane where the display panel is located.

Optionally, the display panel may further include an encapsulation layer700. The encapsulation layer700may be used to encapsulate the light-emitting element300. The encapsulation layer700may include an encapsulation adhesive710. The encapsulation adhesive710may cover the drive substrate200and the light-emitting element300.

The inventors had further found that, in one embodiment that the first film layer250includes a light-absorbing material, the first film layer250may reduce the reflectivity of the display panel. After the first auxiliary layer281is added, the interface between the first auxiliary layer281and the encapsulation adhesive710may be newly added in the display panel. The newly added interface may easily cause the problem of increased reflectivity, which may hinder the realization of the purpose of reducing the reflectivity of the display panel by using the first film layer250.

Based on above, a silicon oxide layer may be included in the first auxiliary layer281. The refractive index of the silicon oxide layer may be similar to the refractive index of the material of the encapsulation layer700. For example, the refractive index of the silicon oxide layer may be similar to the refractive index of the encapsulation adhesive710, which may reduce the interface reflection between the first auxiliary layer281and the encapsulation adhesive710and reduce reflectivity increase problem caused by large refractive index difference.

That is, after trying to use inorganic materials to fabricate the first auxiliary layer, it had been found that in order to ensure the light extraction effect, if the first auxiliary layer is made of an inorganic material, SiO2which has a refractive index similar to the refractive index of glass may need to be used.

However, the inventors had further found that the bonding ability of SiO2and the first film layer formed by an organic material may be poor, that is, if a silicon oxide layer is directly deposited on the first film layer250, the silicon oxide layer may be easily cracked and peeled off. It is necessary to add a silicon nitride layer between the silicon oxide layer and the first film layer250, and the silicon nitride layer may play a transition role between the silicon oxide layer and the first film layer250, which may improve film layer bonding ability between the silicon oxide layer of the first auxiliary layer281and the first film layer250and prevent film layer separation.

Therefore, the first auxiliary layer formed by the inorganic layer may need two sub-layers, which may increase fabrication cost.

In addition, the inorganic layer may need to be formed by a CVD (chemical vapor deposition) manner, and then dry-etched to form a desired pattern, for example, form above-mentioned hollow part. Therefore, the first auxiliary layer formed by the silicon oxide layer and the silicon nitride layer may need at least two CVD film formations. However, in embodiments of the present disclosure, the first auxiliary layer formed by an organic material may only need photolithography to form a patterned film layer, which may simplify technological process and reduce cost.

In addition, the silicon oxide layer and the silicon nitride layer may be limited by material process, which may cause cavity pollution when the film pattern is formed. Through the present disclosure, the cavity pollution caused by above film patterning may be avoided, which may greatly improve production yield.

On the other hand, optionally, the auxiliary film layer and the photoresist pattern may be formed by using a same mask because the first auxiliary layer formed by an organic material may only need photolithography to form a patterned film layer. The mask of the photoresist layer for subsequent patterning of related film layers may be reused; that is, the mask with a same light-blocking region pattern (such as a same mask) may be used to save the cost of mask production. For example, the first auxiliary layer and the photoresist pattern410may be formed using a same mask.

In addition, optionally, the display panel may include the second auxiliary layer282provided in present disclosure; and the second auxiliary layer282may be a film layer formed by an organic material. The first auxiliary layer281may be in contact with the second auxiliary layer281on the side of the first film layer250, exposed by the first opening OP1, away from the first auxiliary layer281, such that the first film layer250may be encapsulated by the organic film layers on adjacent two sides of the first film layer250at the first opening OP1. In addition, the first auxiliary layer281and the second auxiliary layer281formed by the organic film layer may have better bonding performance, which may further improve the effect of blocking the removal solution from invading the first film layer250.

Optionally, in some embodiments, the first auxiliary layer may be a positive photoresist.

Optionally, the thickness of the first film layer250is d2 and the thickness of the first auxiliary layer281is d1; and the sum of the thickness d2 of the first film layer250and the thickness d1 of the first auxiliary layer281is H, that is, H=d1+d2.

It should be noted that d1 refers to the thickness of the part of the first auxiliary layer281covering the first auxiliary layer281; and the thickness direction is the third direction Z.

Optionally, the sum of the thickness of the first film layer250and the thickness of the first auxiliary layer281may satisfy H≤4 μm.

In such way, the opening formed by the first opening and the hollow part may be avoided from being excessively deep, and the light-emitting element may be avoided from not being electrically connected to the electrode240(i.e., the connection part240) on the drive substrate.

Optionally, the drive substrate may include a plurality of electrodes exposed by the first opening; and the plurality of electrodes may respectively correspond to different hollow parts.

For example, the electrode240may be the connection part240described above (the electrode and the connection part share a same label240in present disclosure). The connection part240may include the first connection part241and the second connection part242. The first connection part241and the second connection part242may form the plurality of electrodes. The first connection part241and the second connection part242may correspond to different hollow parts281-arespectively.

Optionally, a same first opening OP1may correspond to multiple hollow parts281-a.

Optionally, the electrodes exposed by a same first opening OP1may correspond to different hollow parts281-arespectively. That is, the first connection part241and the second connection part242corresponding to a same light-emitting element300may correspond to different hollow parts281-arespectively.

Optionally, the second electrode part520may include a part in the hollow part281-aof the first auxiliary layer281.

Optionally, the second electrode part520may further include a part protruding from the hollow part281-a; or in other words, the second electrode part520may further include a part protruding from the upper surface of the first auxiliary film layer281.

Through one embodiment, on one hand, the exposed electrode and the second electrode part520may be defined by the hollow part formed by the auxiliary film layer280. On the other hand, optionally, the first film layer250includes a light-absorbing material. The first film layer250may be used for blocking light and play a role in reducing the reflectivity of the display panel by absorbing external ambient light. Optionally, the first film layer250may be doped with black nanoparticles.

Optionally, the first auxiliary layer281may be a light-transmitting material.

Optionally, the resolution of the first auxiliary layer281may be higher than the resolution of the first film layer250, so that patterning accuracy of the first auxiliary layer may be improved.

Since the first film layer is a light-absorbing material or a light-blocking material, it is normally doped with black nanoparticles. Therefore, its patterning precision may be low, and it is difficult to precisely define the openings having a one-to-one correspondence with the electrodes. In one embodiment, the first auxiliary layer281may be patterned to form a more precise opening pattern, which may improve the alignment reliability between the light-emitting element and the drive substrate. That is, the first auxiliary layer281may remain around the electrode to form a groove, and the eutectic layer may sink to the organic film formed by the first auxiliary layer281, which may reduce falling off problem of the light-emitting element.

Optionally, the density of the first auxiliary layer281may be higher than the density of the first film layer250.

Optionally, the density of the first auxiliary layer281may be higher than the density of the second auxiliary layer282.

As shown inFIGS.6-7orFIGS.22-33, the accompanying drawings related to the method are combined.FIGS.22-23illustrate other cross-sectional views along a line AA′ inFIG.2respectively. The cross-section is perpendicular to the plane where the display panel is located.

Optionally, the drive substrate200may include a plurality of electrodes240exposed by the first openings OP1; and the first auxiliary layer281may include separation elements288between the electrodes240.

In one embodiment, the short circuit problem caused by the metal of the eutectic layer flowing to the surroundings under a high temperature external pressure state may be avoided.

For example, the electrode240may be the connection part240described above.

Optionally, one first opening OP1may expose a plurality of electrodes240, that is, at least two electrodes240may be exposed by a same first opening OP1. The “expose” mentioned here may be understood as the orthographic projection of at least two electrodes240on the substrate may be overlapped with the orthographic projection of a same first opening OP1on the substrate.

Optionally, at least two electrodes240exposed by a same first opening OP1may be electrically connected to a same light-emitting element300.

Optionally, the connection part240may include the first connection part241and the second connection part242. The first connection part241and the second connection part242may form the plurality of electrodes240. The first connection part241and the second connection part242corresponding to a same light-emitting element300may correspond to different hollow parts281-arespectively.

As shown inFIGS.22-23, the distance from the top surface of the separation element288to the electrode is L, where L≤4 μm. According to one embodiment, during the photolithography of the first auxiliary layer281, the first auxiliary layer281may be remained between the electrodes240corresponding to the light-emitting element300, and only the electrode240may be exposed. After the photolithography of the first auxiliary layer281, the height between the upper surface of the first auxiliary layer281between the electrodes240and the upper surface of the electrode240may satisfy L≤2 μm. At this point, it may avoid that the separation element may be in contact with the light-emitting element when the light-emitting element and the drive substrate are aligned and bonded, thereby ensuring that the separation element may not affect the bonding of the light-emitting element when the separation element is used to prevent short-circuit.

Optionally, L≤2 μm, the compatibility of light-emitting elements of various sizes may be fully ensured.

It should be noted that the “top surface” mentioned in present disclosure refers to the surface of the side of the structure facing the light-emitting surface of the display panel100. For example, the electrode separation element288includes two opposite surfaces along the third direction Z, two surfaces may be the bottom surface facing the substrate210and the top surface facing the light-emitting element300, respectively. The top surface of the electrode240may be similar to above description, which may not be described in detail herein.

As shown inFIGS.22-23, optionally, the thickness h of the separation element may be greater than the thickness d1 of the first auxiliary layer281in the upper region of the first film layer. In such way, the separation element may sufficiently block the overflow of the eutectic layer.

Optionally, a part of the first auxiliary layer281on the first film layer250and the separation element288may be made of a same material and a same process.

Optionally, a part of the first auxiliary layer281on the first film layer250may be continuous with the separation element288.

The inventors had found that the position of the part of the first auxiliary layer281on the first film layer250may be higher than the position of the part of the first auxiliary layer281in the first opening OP1, the first auxiliary layer281may be fluid since it is an organic material, and a same material may have a high material thickness at low position. Therefore, the separation element with a higher thickness may be fabricated through a same process. It may be understood that the high position mentioned here may also be farther from the substrate along the third direction Z.

As shown inFIGS.22-23, optionally, the sum of the thicknesses of the first film layer and the first auxiliary layer is H, and the thickness of the separation element is h, where h≤½*H.

That is, the top of the separation element288of the first auxiliary layer281may be lower than the top of the non-separation element region of the first auxiliary layer281. In some embodiments, as shown inFIG.22, the separation element thickness h refers to the distance h1 from the bottom surface to the top surface of the separation element288along the third direction Z. In some embodiments, as shown inFIG.23, the separation element thickness h refers to the distance h2 from the top surface of the separation element288to the top surface of the electrode.

In one embodiment, the separation element may be prevented from pushing up the light-emitting element when the separation element can sufficiently block the flow of the eutectic layer; and the separation element may be avoided to be in contact with the light-emitting element when the light-emitting element and the drive substrate are aligned and bonded, which may ensure that the separation element may not affect the bonding of the light-emitting element when the separation element is used to prevent short-circuit.

Optionally, the thickness of the first film layer250is d2, and the thickness of the first auxiliary layer281is d1; and the sum of the thickness d2 of the first film layer250and the thickness h1 of the first auxiliary layer281is H, and H=d1+d2. It should be noted that d1 refers to the thickness of the part of the first auxiliary layer281covering the first auxiliary layer281, that is, the non-separation element region of the first auxiliary layer281, where the thickness direction is the third direction Z.

Optionally, the sum H of the thickness of the first film layer250and the thickness of the first auxiliary layer281may satisfy H≤4 μm.

In one embodiment, the opening formed by the first opening and the hollow part may be prevented from being excessively deep, so that the light-emitting element cannot be electrically connected to the electrode240(i.e., the connection part240) on the drive substrate.

FIG.24illustrates another cross-sectional view along a line AA′ inFIG.2. The cross section is perpendicular to the plane where the display panel is located.

Optionally, the width of the separation element is D, where D≤5 μm. The direction of the width is the direction pointing from the electrode adjacent to one side of the separation element to the electrode adjacent to the other side of the separation element, that is, the direction in parallel with the connection direction of the electrodes240on two adjacent sides of the separation element288.

Optionally, the distance between the electrodes240corresponding to a same light-emitting element300may be 3-4 μm apart.

Optionally, the width of the separation element may be greater than the distance between the electrodes240corresponding to a same light-emitting element300.

According to embodiments of the present disclosure, the size of the separation element may need to be matched with the electrode configuration. Considering the aspects of increasing the pixel density or reducing the space occupied by the electrodes, the distance between the electrodes may normally not be excessively large, which may require the accuracy of the separation element to meet requirements. However, for above-mentioned first film layer that needs to improve the display effect, it may not satisfy requirements that the material can meet requirements of improving the display effect and also have a high resolution. Therefore, in embodiments of the present disclosure, above-mentioned first auxiliary layer may be used to form the separation element that meets the requirements. Meanwhile, the first auxiliary layer may not only have other functions mentioned above, but also meet required design precision size. In one embodiment, it also provides a size design of the first auxiliary layer that may meet fabrication condition constraints of the first auxiliary layer and also match electrode sizes. Therefore, the reliability of the display panel may be improved without increasing process difficulty.

FIG.25illustrates another cross-sectional view along a line AA′ inFIG.2. The cross section is perpendicular to the plane where the display panel is located.

The second auxiliary layer282may include the thinned part282-b; and the separation element288may be overlapped with the thinned part282-b. The thinned part282-bmay refer to relevant introductions of above-mentioned embodiments.

Optionally, the first auxiliary layer281and the second auxiliary layer282may be in contact with each other in the first opening OP1, which may refer to description of above-mentioned embodiments regarding the encapsulation of the first film layer250by above two layers.

Optionally, the separation element288may be at least partially filled in the groove formed by the thinned part282-b.

Optionally, the top surface of the separation element288may extend beyond the groove formed by the thinned part282-band may be sandwiched between the connection electrodes of two light-emitting elements.

In one embodiment, the first auxiliary layer281and the second auxiliary layer282may be used to cooperate with each other, which may avoid that the height of the separation element288may be too high to push up the light-emitting element.

Optionally, the first auxiliary layer281may form the separation element288; the first auxiliary layer281may be an organic film layer; and the first auxiliary layer281formed by the organic film layer and the separation element288may satisfy some advantages in above-mentioned embodiments. However, in one embodiment, the risk of pushing up the light-emitting element due to the fact that the thickness of the organic film layer itself is normally larger than the thickness of the inorganic layer may be avoided. In addition, the thinned part282-bmay guide the organic material having fluidity during the fabrication process to form the separation element288more easily to the position needed.

Optionally, the formation of the thinned part282-bmay refer to above description, so that the height of the separation element288may be controllable without adding an additional process. Therefore, the first auxiliary layer281may be fabricated without being too concerned about height limit, so that the first auxiliary layer281may have a certain height to meet other design requirements.

FIG.26illustrates a local top view of a drive substrate according to various embodiments of the present disclosure.FIG.27illustrates a cross-sectional view of a display panel according to various embodiments of the present disclosure. The cross section is perpendicular to the plane where the display panel is located.

The second auxiliary layer282may include a thickened part282-c; and the thickened part282-cmay be in the first opening OP1.

Optionally, the projection of the thickened part282-calong the direction perpendicular to the plane where the display panel is located, that is, the third direction Z, may be in the first opening OP1.

Optionally, the protrusion formed by the thickened part282-cmay protrude toward the inside of the first opening OP1to form the effect of being accommodated by the first opening OP1. Therefore, the first opening may be overlapped with the thickened part282-calong the direction parallel to the plane of the display panel.

Optionally, the drive substrate200may include a plurality of electrodes240exposed by the first opening OP1; and at least a part of the electrodes240may be on the thickened part282-c.

In one embodiment, the second auxiliary layer at the bottom of the light-emitting element may be raised, and the electrode may also be raised after the electrode is deposited above the second auxiliary layer. Since the electrode is raised, there is no need to be concerned that the organic first film layer or the first auxiliary layer is too high to cause the light-emitting element to be unable to be aligned, and there is no need to limit the height of the first film layer (because the first film layer may need to meet some above-mentioned other requirements, such as the light-blocking film layer may need to be configured to meet a certain thickness). Therefore, in one embodiment, it may be beneficial for improving the bonding yield of the light-emitting elements.

Optionally, the second auxiliary layer282may include the thickened part282-c. The thickened parts282-cmay be in one-to-one correspondence with at least a part of the light-emitting elements300.

That is, the electrode corresponding to one light-emitting element (optionally, may include the electrode (i.e., a redundant electrode Pre) of a backup light-emitting element in a redundant configuration region corresponding to the light-emitting element) may be raised by one thickened part282-c.

FIG.28illustrates a local top view of a drive substrate according to various embodiments of the present disclosure.

Optionally, the second auxiliary layer282may include thickened parts282-c. At least a part of the thickened parts282-ccorresponding to different light-emitting elements300may be continuous. That is, one thickened part282-cmay simultaneously raise the electrodes240of the plurality of light-emitting elements300.

Optionally, one pixel SP may correspond to one thickening part282-c. That is, the electrode240of the light-emitting element300in a same pixel SP may be overlapped with a same thickened part282-calong the third direction Z, and may be in contact with the thickened part282-cand raised by the thickened part282-c. The introduction of the pixel SP may refer to following or other embodiments of the present disclosure.

Optionally, some optional embodiments of the present disclosure may refer to the drawings related to the light-transmitting region and the non-light-transmitting region of the display panel provided in the present disclosure.

The display panel may include the light-transmitting region and the non-light-transmitting region; the non-light-transmitting region may include a light-emitting element configuration region; the first film layer may further include a second opening; and the second opening may define a pixel light-transmitting region.

FIG.28illustrates a local top view of a drive substrate according to various embodiments of the present disclosure.FIGS.29-30respectively illustrate other enlarged schematics of local regions of a display panel inFIG.1.FIG.31illustrates a cross-sectional view along a line DD′ inFIG.29orFIG.30. The parts inFIGS.29-31that are same as above-mentioned drawings may refer to above-mention description, which may not be described in detail herein.

The display panel may include a pixel light-transmitting region PTA and a non-light-transmitting region PNTA; and the non-light-transmitting region PNTA may include a light-emitting element configuration region.

The light-emitting element configuration region may be the region for bonding the light-emitting elements300. As shown inFIG.29, the light-emitting element configuration region may include regions for respectively configuring a blue light-emitting element PB, a green light-emitting element PG, and a red light-emitting element PR. In addition, as shown inFIG.30, the light-emitting element configuration region may include regions for respectively configuring the blue light-emitting element PB, the green light-emitting element PG, and the red light-emitting element PR, and include the redundant electrode Pre. When the bonded light-emitting element300fails, normal light-emitting element300may be re-bonded in the redundant electrode Pre for repair (the light-emitting element for subsequent repair is temporarily referred to as a backup light-emitting element in other embodiments of the present disclosure). Two connection parts240in the redundant electrode Pre may be respectively connected to two connection parts240in adjacent light-emitting element configuration region respectively.

The blue light-emitting element PB, the green light-emitting element PG, and the red light-emitting element PR may be used to form the pixel SP.

The first film layer250may include a light-absorbing material and transmit light through the openings. The first film layer250may be provided with the first opening OP1and the second opening OP2; the first opening OP1may define the light-emitting element configuration region; and the second opening OP2may define the pixel light-transmitting region PTA.

The planarization layer230(optionally, the second auxiliary layer282) may be provided with the fourth opening. The fourth opening may be overlapped with the pixel light-transmitting region PTA, and the first film layer250may cover the sidewall of the fourth opening of the planarization layer230for blocking light and reducing reflection.

The first auxiliary layer281may cover the sidewall of the first opening OP1and the sidewall of the second opening OP2of the first film layer250.

The first auxiliary layer281may be provided with the fifth opening. The fifth opening may be in the pixel light-transmitting region PTA, and the shape of the fifth opening may be a rectangle with four corners removed, for example, a rounded rectangle. By using such solution, it may improve the situation of holes in the first organic layer or holes in the first auxiliary layer caused by the high-level difference at the edge of the pixel light-transmitting region PTA, as well as other issues including the leakage of the removal solution, over-etching of four corners, and the like.

Optionally, in some optional embodiments of the present disclosure which may refer to relevant drawings related to the encapsulation layer700provided in the present disclosure, the drive substrate200may include the redundant electrode Pre. Since the eutectic process does not occur, the redundant electrode Pre may be the second electrode part520. In one embodiment, the redundant electrode Pre may include gold (Au).

Optionally, in some optional embodiments of the present disclosure which may refer to relevant drawings related to the encapsulation layer700provided in the present disclosure, the display panel may further include the encapsulation layer700. The encapsulation layer700may include an encapsulation adhesive710and a cover plate720. The encapsulation adhesive710may cover the drive substrate200and be used to encapsulate the light-emitting element300. The encapsulation adhesive710may cover the side surface of the light-emitting element300and may also cover the upper surface of the light-emitting element300.

It should be noted that, in other drawings that do not illustrate the encapsulation layer700, the encapsulation layer700may also be disposed above the drive substrate of the display panel, and specific structure of the encapsulation layer700may be referred to related drawings.

Optionally, in some optional embodiments of the present disclosure which may refer to relevant drawings related to the encapsulation layer700provided in the present disclosure, the display panel may further include a black matrix800. The black matrix800may be on the side of the encapsulation adhesive710away from the drive substrate200. The black matrix800may be provided with the first light-transmitting hole810and the second light-transmitting hole820; the first light-transmitting hole810may be in the light-emitting element configuration region; and the second light-transmitting hole820may be in the pixel light-transmitting region PTA. The black matrix800may be in a mesh shape; and the first light-transmitting hole810and the second light-transmitting hole820may be meshes. The black matrix800may reduce the reflectivity of the display panel while reducing the crosstalk between the light-emitting elements300.

Along the second direction, the distance between the edge of the first light-transmitting hole810and the light-emitting element300may be less than the distance between the edge of the first opening OP1and the light-emitting element300, where the second direction is in parallel with the plane of the display panel. With such configuration, the problem of high reflectivity caused by the connection part240in the first opening OP1may be further improved.

Optionally, in some optional embodiments of the present disclosure which may refer to relevant drawings related to the encapsulation layer700provided in the present disclosure, the encapsulation layer700of the display panel may further include an adhesive layer730; and the adhesive layer730may be between the encapsulation adhesive710and the cover plate720.

Optionally, in some optional embodiments of the present disclosure which may refer to relevant drawings related to the encapsulation layer700provided in the present disclosure, the display panel may further include a color resist900covering the light-emitting element300, which is configured to filter light and improve light purity.

Optionally, in some optional embodiments of the present disclosure which may refer to relevant drawings related to the encapsulation layer700provided in the present disclosure, the drive substrate may further include the redundant electrode Pre. Since the eutectic process does not occur, the redundant electrode Pre may be the second electrode part520. In one embodiment, the redundant electrode Pre may include gold (Au), and the color resist900may cover the redundant electrode Pre, thereby reducing the influence of the redundant electrode Pre on the reflectivity of the display panel.

The color resistors900may include a blue color resistor910, a green color resistor920and a red color resistor930; and the light-emitting elements300may include a blue light-emitting element PB, a green light-emitting element PG and a red light-emitting element PR. The blue color resist910may cover the blue light-emitting element PB, the green color resist920may cover the green light-emitting element PG, and the red color resist930may cover the red light-emitting element PR. In other embodiments, the red color resistance may not be disposed. On one hand, the light extraction efficiency of the red light-emitting element may be low, and the addition of the red color resistance may further reduce the light extraction efficiency of the light-emitting element. On the other hand, most of the wavelength bands of the light reflected by the redundant electrode Pre or the connection part240may be wavelength bands of reddish light, even if the red color resist is disposed, the anti-reflection effect may be extremely limited.

FIGS.32-38illustrate local enlarged top views and related cross-sectional views of a display panel, respectively.

Optionally, the drive substrate may include a plurality of electrodes240exposed by the first opening OP1; and the electrode240may have the groove204. That is, a concave-convex structure may be formed on the upper surface of the electrode240.

In one embodiment, since the eutectic layer flows under the action of high temperature and external force when the light-emitting element is bonded, the electrode may be patterned, and the adhesion between the eutectic layer and the electrode may be increased through the patterning of the electrode and the concave-convex structure on the side of the electrode.

Optionally, the opening of the groove204may face the light-emitting element300.

It should be noted that the dotted box in the drawings represents the region where the light-emitting element or the backup light-emitting element is disposed; and two electrodes240may correspond to a same light-emitting element300, which may refer to specific description above.

FIGS.35to38illustrate the cross-sectional views along the cross-section line at position {circle around (1)} and the cross-section line at position {circle around (2)}; and also illustrate different groove modes, that is, hollow grooves and non-hollow grooves. The cross-section direction is perpendicular to the plane direction of the display panel.

Optionally, the groove204may be a groove which passes through a part of the electrode240or a groove which does not pass through the electrode240. The passing-through direction is a direction perpendicular to the plane of the display panel.

As shown inFIG.36, the groove204may be a non-passing-through groove204.

Optionally, as shown inFIGS.33and35-38, at least a part of the groove204may pass through the edge of the electrode240. That is, the pattern of the orthographic projection of the groove on the substrate may include an opening connected to the outside of the electrode. In other words, there is a notch in the outer contour of the electrode. In one embodiment, an opening may be designed on the outside of the electrode, which may guide the eutectic layer to flow toward the outside of the light-emitting element, and lead out the overflowing eutectic layer, which may avoid short circuit between the cathode and anode of the light-emitting element.

Optionally, in the electrode240corresponding to a same light-emitting element300, the electrode240may include a first edge A facing away from the other electrode240, and the groove204may pass through a part of the first edge A. The inventors had found that if the light-emitting element is bonded and then undergoes a high-temperature process, the eutectic layer may reflow, resulting in an increase in dark spots. In one embodiment, no drainage opening may be designed between the cathode and anode electrodes of the LED (light-emitting diode), and only a drainage opening may be designed around the LED. In such way, the overflowing eutectic layer may be controlled to be led out, and the overflowing eutectic layer of different electrodes may be guided along the direction away from the other electrode, which may further optimize the effect of preventing short circuit.

Optionally, as shown inFIG.34, the connection positions between the grooves204and the light-emitting element300may not be overlapped with each other.

Optionally, at least a part of the grooves204may be between the redundant configuration region and the light-emitting element300. In such way, the fabrication of subsequent backup light-emitting element that affects the redundant configuration region may be prevented from being affected by the eutectic layer of the light-emitting element fabricated previously.

The present disclosure also provides a display apparatus including the display panel provided by the present disclosure.FIG.39illustrates a schematic of a display apparatus according to various embodiments of the present disclosure. The display apparatus1000may include the display panel100provided by any one of above embodiments of the present disclosure. Embodiment ofFIG.39only takes a mobile phone as an example to describe the display apparatus1000. It may be understood that the display apparatus provided by embodiments of the present disclosure may be a computer, a TV, a vehicle-mounted display apparatus, or other display apparatus having a display function, which may not be limited by the present disclosure. The display apparatus provided by embodiments of the present disclosure may have the beneficial effects of the display panel provided by embodiments of the present disclosure, which may refer to description of the display panel in above-mentioned embodiments and may not be described in detail in one embodiment.

The reliability of the display panel may be improved through the present disclosure.

The above is a further detailed description of the present disclosure in conjunction with optional embodiments, and the implementation of the present disclosure may not be limited to such description. For those skilled in the art, without departing from the concept of the present disclosure, certain simple deductions or substitutions may be made which should be regarded as the protection scope of the present disclosure.