Driver substrate, display panel, manufacturing method thereof, and display device

Abstract

An embodiment of the present application provides a driving substrate, a display panel, a manufacturing method thereof, and a display device. By arranging the electrode structure for electrically connecting with the micro light-emitting diode in a double-layer manner, and a stepped layer is arranged between the first electrode layer and the second electrode layer. Among them, the first electrode layer includes a first comb-shaped electrode and a second comb-shaped electrode with comb-shaped parts arranged in an interleaved manner, the second electrode layer includes a third comb-shaped electrode and a fourth comb-shaped electrode with comb-shaped parts arranged in an interleaved manner, the third comb-shaped electrode is electrically connected to the first comb-shaped electrode, and the fourth comb-shaped electrode is electrically connected to the second comb-shaped electrode, the micro light-emitting diode can be limited within the range of the electrode structure, which is beneficial to improving the contact probability between the two poles of the micro light-emitting diode and the electrode structure, and the double-layer interleaved comb-shaped electrodes are beneficial to improving the probability of correctly connecting the micro light-emitting diode and the electrode structure, thereby effectively improving the lighting probability of the micro light-emitting diode.

Description

Technical Field

[0001] The present application relates to the field of display technologies. Specifically, the present application relates to a driving substrate, a display panel, a manufacturing method thereof, and a display device. Background Art

[0002] In a QNED display device, nanoscale LEDs (which can also be referred to as LED nanorods) are transported onto a driving substrate by a liquid transfer method, and then a color conversion layer is formed. Among them, by selecting the material of the color conversion layer, color display can be achieved under the excitation of the light emitted by the nanoscale LEDs.

[0003] Theoretically, QNED display devices have advantages such as long lifespan, high brightness, low power consumption, and non-combustion. However, due to the too small size of the nanoscale LEDs, they can only be transported by solution, such as printing. In this case, after the LED nanorods are ejected from the printing device, the electrode directions of the LED nanorods are disordered, but the electrode sizes and positions on the driving substrate are fixed. In this case, a large portion of the LED nanorods will not be lit, which not only reduces the display brightness but also wastes a large amount of nanoscale LEDs. Summary of the Invention

[0004] In view of the disadvantages of the existing methods, the present application provides a driving substrate, a display panel, a manufacturing method thereof, and a display device to solve the technical problem that a large number of LED nanorods in the existing QNED display device cannot be lit.

[0005] In a first aspect, an embodiment of the present application provides a driving substrate for driving micro light-emitting diodes, including a substrate and a plurality of first power lines, a plurality of second power lines, and a plurality of pixel circuits located on the substrate. Each pixel circuit drives at least one sub-pixel; the driving substrate further includes:

[0006] A plurality of electrode structures located on a side of the pixel circuit away from the substrate, and the electrode structures correspond to the sub-pixels one by one. The electrode structure includes a first electrode layer, a step layer, and a second electrode layer arranged in sequence in a direction away from the substrate;

[0007] A pixel defining layer is provided with a plurality of openings penetrating the pixel defining layer on a side away from the substrate. The orthographic projection of the edge of each electrode structure on the substrate covers the orthographic projection of one of the openings on the substrate;

[0008] The first electrode layer includes a first comb-shaped electrode and a second comb-shaped electrode with comb teeth arranged in an interleaved manner. The first comb-shaped electrode is electrically connected to the pixel circuit, and the second comb-shaped electrode is electrically connected to the first power line or the second power line;

[0009] The stepped layer includes a main step and a plurality of auxiliary steps connected to the main step and located within the opening. The main step corresponds to each sub-pixel one by one. The orthographic projection of each main step on the substrate covers the orthographic projections of the comb handles of the first comb-shaped electrode and the second comb-shaped electrode on the substrate. The extending direction of the auxiliary step intersects with the extending direction of the comb teeth of the first comb-shaped electrode, and the width of the opening is smaller than the width of the edge step;

[0010] The second electrode layer includes a third comb-shaped electrode and a fourth comb-shaped electrode with their comb teeth arranged in a staggered manner. The third comb-shaped electrode is electrically connected to the first comb-shaped electrode and the extending direction of its comb handle is the same as the extending direction of the comb teeth of the first comb-shaped electrode. The fourth comb-shaped electrode is electrically connected to the second comb-shaped electrode and the extending direction of its comb handle is the same as the extending direction of the comb teeth of the second comb-shaped electrode. The comb handles of the third comb-shaped electrode and the fourth comb-shaped electrode are both located on the main step, and the comb teeth of the third comb-shaped electrode and the fourth comb-shaped electrode are both located on the auxiliary step.

[0011] Optionally, the first electrode layer includes a first conductive layer and a second conductive layer located on the side of the first conductive layer away from the substrate. The melting point of the second conductive layer is lower than that of the first conductive layer; the second electrode layer includes a third conductive layer and a fourth conductive layer located on the side of the third conductive layer away from the substrate. The melting point of the fourth conductive layer is lower than that of the third conductive layer and lower than that of the first conductive layer.

[0012] Optionally, the driving substrate further includes:

[0013] A reflective layer, located between the substrate and the first conductive layer, includes a plurality of reflective units. The orthographic projection of the reflective unit on the substrate covers the orthographic projection of the opening on the substrate;

[0014] A fourth insulating layer, located between the reflective layer and the first electrode layer.

[0015] Optionally, the widths of the comb teeth portions of the first comb-shaped electrode, the second comb-shaped electrode, the third comb-shaped electrode, and the fourth comb-shaped electrode are equal; the length of the micro light-emitting diode is d, and the width of the comb teeth portion of the first comb-shaped electrode is d1, then 25% d - 0.1 μm ≤ d1 ≤ 25% d + 0.1 μm; the distance between the comb teeth portion of the first comb-shaped electrode and the comb teeth portion of the second comb-shaped electrode is equal to d2, the distance between the comb teeth portion of the third comb-shaped electrode and the comb teeth portion of the fourth comb-shaped electrode is equal to d2, and 80% d1 ≤ d2 ≤ 120% d1.

[0016] Optionally, the widths of the comb handle portions of the first comb-shaped electrode, the second comb-shaped electrode, the third comb-shaped electrode, and the fourth comb-shaped electrode are equal; the width of the comb handle portion of the first comb-shaped electrode is equal to the width of the main step, and the width of the main step is 5 μm to 15 μm.

[0017] Optionally, the thickness of the step layer is h, 50% d ≤ h ≤ 75% d; the thickness of the pixel definition layer is 2 μm to 8 μm.

[0018] Optionally, the pixel circuit includes at least one driving signal output terminal, a first overlapping electrode, and a second overlapping electrode; the driving signal output terminal is configured to output a driving signal to one of the sub-pixels; the first overlapping electrode is electrically connected to the driving signal output terminal and the first comb-shaped electrode respectively; the second overlapping electrode is electrically connected to the first power line or the second power line and the second comb-shaped electrode respectively.

[0019] In a second aspect, an embodiment of the present application provides a display panel, which includes:

[0020] The above-mentioned driving substrate;

[0021] A light-emitting layer, including a plurality of light-emitting units located in the opening, and the light-emitting unit includes a plurality of randomly distributed micro light-emitting diodes located in the same opening. When the two poles of the micro light-emitting diode are electrically connected to the first electrode structure and the second electrode structure respectively, the micro light-emitting diode can be lit.

[0022] A color conversion layer, including a plurality of color conversion units, each of the color conversion units is located in one of the openings and on the side of the light-emitting layer away from the driving substrate, and the color conversion unit includes a first color conversion unit, a second color conversion unit, and a third color conversion unit.

[0023] In a third aspect, an embodiment of the present application provides a display device, which includes:

[0024] The above-mentioned display panel;

[0025] A driving chip, electrically connected to the display device, provides a first power voltage and a second power voltage to the display panel;

[0026] During the period of one frame of display screen, the voltages on the first power lines of odd rows and the second power lines of even rows are both the first power voltage, and the voltages on the second power lines of odd rows and the first power lines of even rows are both the second power voltage;

[0027] During the display periods of two consecutive frames, the voltage of the first power line of odd rows in the previous frame display period is the first power voltage, the voltage of the second power line of even rows is the second power voltage, the voltage of the first power line of odd rows in the next frame display period is the second power voltage, and the voltage of the second power line of even rows is the first power voltage.

[0028] In a fourth aspect, an embodiment of the present application provides a method for manufacturing a display panel, including:

[0029] Providing the above-mentioned driving substrate;

[0030] Depositing micro light-emitting diodes on the driving substrate by coating or spraying to form a light-emitting layer, the light-emitting layer includes a plurality of light-emitting units located in the openings, and each of the light-emitting units includes a plurality of randomly distributed micro light-emitting diodes located in each of the openings;

[0031] Heating the driving substrate to melt the upper surface of the electrode structure so that the two poles of the micro light-emitting diode are wrapped by the melted electrode structure;

[0032] After the electrode structure is cured and fixedly connected to the two poles of the micro light-emitting diode, a color conversion layer is formed by printing or patterning, the color conversion layer includes a plurality of color conversion units, each color conversion unit is located in one of the openings, and the color conversion unit includes a first color conversion unit, a second color conversion unit and a third color conversion unit.

[0033] The beneficial technical effects brought by the technical solution provided by the embodiment of the present application include:

[0034] 1) The driving substrate, display panel, and display device provided in this embodiment can limit the micro light-emitting diodes within the range of the electrode structure by arranging the electrode structure for electrically connecting to the micro light-emitting diodes in a double layer, and a stepped layer is arranged between the first electrode layer and the second electrode layer. Among them, the first electrode layer includes a first comb-shaped electrode and a second comb-shaped electrode with their comb-shaped parts arranged alternately, the second electrode layer includes a third comb-shaped electrode and a fourth comb-shaped electrode with their comb-shaped parts arranged alternately, the third comb-shaped electrode is electrically connected to the first comb-shaped electrode, and the fourth comb-shaped electrode is electrically connected to the second comb-shaped electrode. This can increase the contact probability between the two poles of the micro light-emitting diode and the electrode structure, and the double-layer alternating comb-shaped electrodes are beneficial to increasing the probability of correctly connecting the micro light-emitting diode to the electrode structure, thereby effectively increasing the lighting probability of the micro light-emitting diode.

[0035] 2) The driving substrate, display panel, and display device provided in this embodiment use time-division driving during driving. In two adjacent frames, the micro light-emitting diodes with the P pole connected to the first electrode structure and the N pole connected to the second electrode structure emit light in the previous frame, and the micro light-emitting diodes with the N pole connected to the first electrode structure and the P pole connected to the second electrode structure emit light in the next frame, so that the lighting probability of the micro light-emitting diodes exceeds 90%.

[0036] 3) The manufacturing method of the display panel provided in this embodiment is relatively simple, and the lighting probability of the micro light-emitting diodes in the formed display panel is high.

[0037] The additional aspects and advantages of this application will be partially given in the following description, and these will become obvious from the following description, or will be understood through the practice of this application. Description of the Drawings

[0038] The above-mentioned and / or additional aspects and advantages of this application will become obvious and easy to understand from the following description of the embodiments in conjunction with the drawings, where:

[0039] Figure 1 is a partial top view schematic diagram of a driving substrate provided in an embodiment of this application;

[0040] Figure 2 is a top view schematic diagram of the electrode structure in the driving substrate provided in an embodiment of this application;

[0041] Figure 3 is a partial cross-sectional schematic diagram of a driving substrate provided in an embodiment of this application;

[0042] Figure 4 is a top view schematic diagram of the stepped layer in the driving substrate provided in an embodiment of this application;

[0043] Figure 5 is a partial cross-sectional schematic diagram of another driving substrate provided in an embodiment of this application;

[0044] Figure 6 It is a circuit diagram of a pixel circuit in a driving substrate provided by an embodiment of the present application;

[0045] Figure 7 It is a cross-sectional schematic diagram of a pixel circuit provided by an embodiment of the present application;

[0046] Figure 8 It is a structural schematic diagram of a first electrode layer in a driving substrate provided by an embodiment of the present application;

[0047] Figure 9 It is a structural schematic diagram of a second electrode layer in a driving substrate provided by an embodiment of the present application;

[0048] Figure 10 It is a partial cross-sectional schematic diagram of a display panel provided by an embodiment of the present application;

[0049] Figure 11 It is a connection schematic diagram of a micro light-emitting diode and an electrode structure in a side view angle in a display panel provided by an embodiment of the present application;

[0050] Figure 12 It is a connection schematic diagram of a micro light-emitting diode and an electrode structure in a top view angle in a display panel provided by an embodiment of the present application;

[0051] Figure 13 It is a schematic diagram of a frame structure of a display device provided by an embodiment of the present application;

[0052] Figure 14 It is a schematic flow chart of a manufacturing method of a display panel provided by an embodiment of the present application.

[0053] 1 - Substrate substrate;

[0054] 2 - Pixel circuit; 201 - Buffer layer; 202 - Active layer; 2021 - Source region; 2022 - Channel region; 2023 - Drain region; 203 - First gate insulating layer; 204 - Second gate insulating layer; 205 - First insulating layer; 206 - Second insulating layer; 207 - Third insulating layer; 208 - First overlapping electrode; 209 - Second overlapping electrode;

[0055] 3 - Electrode structure; 31 - First electrode layer; 311 - First comb-shaped electrode; 3111 - First comb handle part; 3112 - First comb tooth part; 312 - Second comb-shaped electrode; 3121 - Second comb handle part; 3122 - Second comb tooth part; 32 - Step layer; 321 - Main step; 322 - Auxiliary step; 33 - Second electrode layer; 331 - Third comb-shaped electrode; 3311 - Third comb handle part; 3312 - Third comb tooth part; 332 - Fourth comb-shaped electrode; 3321 - Fourth comb handle part; 3322 - Fourth comb tooth part;

[0056] 4-pixel definition layer; 401-opening;

[0057] 5-reflection layer;

[0058] 6- fourth insulating layer;

[0059] 7-light-emitting layer; 71-light-emitting unit; 711-micro light-emitting diode;

[0060] 8-color conversion layer; 81-first color conversion unit; 82-second color conversion unit; 83-third color conversion unit;

[0061] 10-first power line; 20-second power line; 30-data line. DETAILED DESCRIPTION

[0062] The following describes the embodiments of the present application in conjunction with the accompanying drawings. It should be understood that the embodiments described below in conjunction with the accompanying drawings are exemplary descriptions for explaining the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions of the embodiments of the present application.

[0063] Those skilled in the art will understand that, unless otherwise stated, the singular forms "a," "an," "said," and "the" used herein may also include the plural forms. It should be further understood that the term "comprising" used in the specification of this application refers to the presence of the described features, integers, steps, operations, elements, and / or components, but does not exclude the implementation of other features, information, data, steps, operations, elements, components, and / or combinations thereof supported by the technical field. It should be understood that when we refer to an element as being "connected" or "coupled" to another element, the element may be directly connected or coupled to the other element, or it may refer to the element and the other element establishing a connection relationship through an intermediate element. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein refers to at least one of the items defined by the term, for example, "A and / or B" may be implemented as "A," or as "B," or as "A and B."

[0064] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0065] First, several terms involved in this application are introduced and explained:

[0066] QNED display device: where "Q" refers to quantum dot materials, which are not used for light emission but for color conversion; "N" refers to nanoscale. "NED" is a nanoscale light-emitting diode, that is, a nanoscale LED or an LED nanorod, which is a rod-shaped LED with a length between several hundred nanometers and several thousand nanometers. The QNED display device is a display device that combines nanoscale LEDs and quantum dot technology, where the nanoscale LEDs are used as light-emitting devices, and different quantum dot materials emit different colors of light under the light emitted by the nanoscale LEDs.

[0067] Theoretically, the QNED display device has the advantages of long lifespan, high brightness, low power consumption, and flame retardancy. However, due to the too-small size of the nanoscale LEDs, they can only be transported in a solution-based manner, such as by printing. In this case, after the LED nanorods are ejected from the printing device, the electrode directions of the LED nanorods are disordered, while the electrode sizes and positions on the driving substrate are fixed. In this situation, a large portion of the LED nanorods will not be lit, which not only reduces the display brightness but also wastes a large amount of nanoscale LEDs.

[0068] The driving substrate, display panel, its manufacturing method, and display device provided in this application aim to solve the above technical problems in the prior art.

[0069] The following uses specific embodiments to elaborate in detail on the technical solutions of this application and how the technical solutions of this application solve the above technical problems. It should be noted that the following embodiments can refer to, draw on, or combine with each other. For the same terms, similar features, and similar implementation steps in different embodiments, they will not be described repeatedly.

[0070] This embodiment provides a driving substrate for driving micro light-emitting diodes. The following combines Figures 1 to 9 to describe the driving substrate provided in this embodiment.

[0071] As Figure 1 and Figure 3 shown, the driving substrate provided in this embodiment includes a substrate 1 and a plurality of first power lines 10, a plurality of second power lines 20, and a plurality of pixel circuits 2 located on the substrate 1. Each pixel circuit 2 drives at least one sub-pixel.

[0072] As Figure 2 and Figure 3As shown in the figure, the driving substrate provided in this embodiment further includes a plurality of electrode structures 3 and a pixel definition layer 4. The electrode structures 3 are located on the side of the pixel circuit 2 away from the substrate, and the electrode structures 3 correspond to the sub-pixels one by one. The electrode structure 3 includes a first electrode layer 31, a step layer 32, and a second electrode layer 33 arranged in sequence in the direction away from the substrate 1. The pixel definition layer 4 is located on the side of the electrode structure 3 away from the substrate 1, includes openings and a plurality of openings 401 penetrating the pixel definition layer 4. The orthographic projection of the edge of each electrode structure 3 on the substrate 1 covers the orthographic projection of an opening 401 on the substrate 1.

[0073] As Figure 2 shown in the figure, the first electrode layer 31 includes a first comb-shaped electrode 311 and a second comb-shaped electrode 312 with their comb teeth arranged staggeredly. The first comb-shaped electrode 311 is electrically connected to the pixel circuit 2, and the second comb-shaped electrode 312 is electrically connected to the first power line 10 or the second power line 20.

[0074] As Figures 2 to 4 shown in the figure, the step layer 32 includes a main step 321 and a plurality of auxiliary steps 322 connected to the main step 321 and located within the opening 401. The main step 321 corresponds to the sub-pixels one by one. The orthographic projection of each main step 321 on the substrate 1 covers the orthographic projection of the comb handle parts of the first comb-shaped electrode 311 and the second comb-shaped electrode 312 on the substrate 1. The extending direction of the auxiliary step 322 intersects with the extending direction of the comb teeth of the first comb-shaped electrode 311. The width of the opening is smaller than the width of the edge step;

[0075] As Figures 2 to 4 shown in the figure, the second electrode layer 33 includes a third comb-shaped electrode 331 and a fourth comb-shaped electrode 332 with their comb teeth arranged staggeredly. The third comb-shaped electrode 331 is electrically connected to the first comb-shaped electrode 311 and the extending direction of its comb handle is the same as the extending direction of the comb teeth of the first comb-shaped electrode 311. The fourth comb-shaped electrode 332 is electrically connected to the second comb-shaped electrode 312 and the extending direction of its comb handle is the same as the extending direction of the comb teeth of the second comb-shaped electrode 312. The comb handle parts of the third comb-shaped electrode 331 and the fourth comb-shaped electrode 332 are both located on the main step 321. The comb teeth parts of the third comb-shaped electrode 331 and the fourth comb-shaped electrode 332 are both located on the auxiliary step 322.

[0076] As Figure 2 shown in the figure, the third comb-shaped electrode 331 is electrically connected to the first comb-shaped electrode 311 through a first via h1, and the fourth comb-shaped electrode 332 is electrically connected to the second comb-shaped electrode 312 through a second via h2.

[0077] As Figure 2As shown, for ease of explanation, in the following embodiments, the handle portion of the first comb-shaped electrode 311 is referred to as the first handle portion 3111, and the tooth portion of the first comb-shaped electrode 311 is referred to as the first tooth portion 3112; the handle portion of the second comb-shaped electrode 312 is referred to as the second handle portion 3121, and the tooth portion of the second comb-shaped electrode 312 is referred to as the second tooth portion 3122; the handle portion of the third comb-shaped electrode 331 is referred to as the third handle portion 3311, and the tooth portion of the third comb-shaped electrode 331 is referred to as the third tooth portion 3312; the handle portion of the fourth comb-shaped electrode 332 is referred to as the fourth handle portion 3321, and the tooth portion of the fourth comb-shaped electrode 332 is referred to as the fourth tooth portion 3322.

[0078] Please refer to Figure 11 and Figure 12 , when the two poles (P pole and N pole) of the micro light-emitting diode are electrically connected to the first electrode structure 3 or the second electrode structure 3 respectively, the micro light-emitting diode can be lit. Specifically, the first electrode structure 3 includes the first comb-shaped electrode 311 and the third comb-shaped electrode 331, and the second electrode structure 3 includes the second comb-shaped electrode 312 and the fourth comb-shaped electrode 332.

[0079] In the driving substrate provided in this embodiment, by arranging the electrode structure 3 for electrically connecting with the micro light-emitting diode in a double layer, and a step layer 32 is arranged between the first electrode layer 31 and the second electrode layer 33. Among them, the first electrode layer 31 includes the first comb-shaped electrode 311 and the second comb-shaped electrode 312 with staggered tooth portions, the second electrode layer 33 includes the third comb-shaped electrode 331 and the fourth comb-shaped electrode 332 with staggered tooth portions, the third comb-shaped electrode 331 is electrically connected to the first comb-shaped electrode 311, and the fourth comb-shaped electrode 332 is electrically connected to the second comb-shaped electrode 312, the micro light-emitting diode can be limited within the range of the electrode structure 3. This is beneficial to increasing the contact probability between the two poles of the micro light-emitting diode and the electrode structure, and the double-layer staggered comb-shaped electrodes are beneficial to increasing the probability of correct connection between the micro light-emitting diode and the electrode structure, thereby effectively increasing the lighting probability of the micro light-emitting diode.

[0080] As Figure 3 shown, in the driving substrate provided in this embodiment, the widths of the first tooth portion 3112, the second tooth portion 3122, the third tooth portion 3312, and the fourth tooth portion 3322 are equal; the length of the micro light-emitting diode is d, and the width of the first tooth portion 3112 is d1, then 25% d - 0.1 μm ≤ d1 ≤ 25% d + 0.1 μm; the distance between the first tooth portion 3112 and the second tooth portion 3122 is equal to d2, the distance between the third tooth portion 3312 and the fourth tooth portion 3322 is equal to d2, and 80% d1 ≤ d2 ≤ 120% d1.

[0081] As Figure 3As shown, the widths of the first comb handle portion 3111, the second comb handle portion 3121, the third comb handle portion 3311, and the fourth comb handle portion 3321 are equal; the width of the first comb handle portion 3111 is equal to the width of the main step 321, and the width of the main step 321 is 5 μm to 15 μm.

[0082] As Figure 3 shown, the thickness of the step layer 32 is h, 50% d ≤ h ≤ 75d; the thickness of the pixel definition layer 4 is 2 μm to 8 μm.

[0083] In a specific embodiment, the length of the micro light-emitting diode is 2 μm. At this time, the width d1 of the first comb tooth portion 3112 is 0.3 μm to 0.5 μm, the distance d2 between the first comb tooth portion 3112 and the second comb tooth portion 3122 is 0.3 μm to 0.5 μm, and the thickness of the step layer 32 is 1 μm to 1.5 μm.

[0084] As Figure 5 shown, the driving substrate provided in this embodiment further includes a reflective layer 5 and a fourth insulating layer 6. The reflective layer 5 is located between the substrate 1 and the first conductive layer, and includes a plurality of reflective units. The orthographic projection of the reflective units on the substrate 1 covers the orthographic projection of the opening 401 on the substrate 1; the insulating layer is located between the reflective layer 5 and the first electrode layer 31.

[0085] Specifically, the reflective layer 5 is made of a metal with a relatively high reflectivity such as silver or aluminum, and the thickness is about The distance between adjacent reflective units is 3 μm to 10 μm. By providing the reflective layer 5, the light irradiated on the reflective layer 5 can be reflected, thereby improving the display brightness.

[0086] Specifically, the fourth insulating layer 6 is used to prevent the electrode structure 3 from being connected to the reflective layer 5. The material of the fourth insulating layer 6 is SiO2 or SiN with a relatively high transmittance, and the thickness is 100 nm to 300 nm.

[0087] As Figure 8 and Figure 9 shown, in the driving substrate provided in this embodiment, the first electrode layer 31 includes a first conductive layer 3101 and a second conductive layer 3102 located on the side of the first conductive layer 3101 away from the substrate 1. The melting point of the second conductive layer 3102 is lower than that of the first conductive layer 3101; the second electrode layer 33 includes a third conductive layer 3301 and a fourth conductive layer 3302 located on the side of the third conductive layer 3301 away from the substrate 1. The melting point of the fourth conductive layer 3302 is lower than that of the third conductive layer 3301 and lower than that of the first conductive layer 3101.

[0088] Specifically, as Figure 8As shown, the thickness of the first conductive layer 3101 is 200 nm to 500 nm. The material of the first conductive layer 3101 includes aluminum and molybdenum. For example, a molybdenum / aluminum / molybdenum laminated structure is adopted, and this molybdenum / aluminum / molybdenum laminated structure has good electrical conductivity.

[0089] Specifically, as Figure 8 shown, the thickness of the second conductive layer 3102 is about 100 nm, and a copper-tin composite material with a relatively low melting point is used, so that the driving substrate can be heated at a relatively low temperature to be melted. The melted second conductive layer 3102 can wrap the two poles of the micro light-emitting diode, realizing a stable connection between the micro light-emitting diode and the electrode structure 3. Of course, the second conductive layer 3102 can also be made of tin.

[0090] Specifically, as Figure 9 shown, the thickness of the third conductive layer 3301 is 200 nm to 500 nm. The material of the first conductive layer 3301 includes aluminum and molybdenum. For example, a molybdenum / aluminum / molybdenum laminated structure is adopted, and this molybdenum / aluminum / molybdenum laminated structure has good electrical conductivity.

[0091] Specifically, as Figure 9 shown, the thickness of the fourth conductive layer 3302 is about 100 nm, and a copper-tin composite material with a relatively low melting point is used, so that the driving substrate can be heated at a relatively low temperature to be melted. The melted fourth conductive layer 3302 can wrap the two poles of the micro light-emitting diode, realizing a stable connection between the micro light-emitting diode and the electrode structure 3. Of course, the fourth conductive layer 3302 can also be made of tin.

[0092] In the driving substrate provided in this embodiment, the pixel circuit 2 can adopt various structures. Generally, the pixel circuit 2 of the OLED can be applied to the driving substrate provided in this embodiment. For example, the pixel circuit 2 as Figure 6 shown can be adopted. This pixel circuit 2 is used to drive 3 sub-pixels, and the above 3 sub-pixels are represented by D1, D2, and D3 respectively.

[0093] As Figure 6 shown, in this pixel circuit 2, the first power line 10, the second power line 20, and the data line 30 are shared, and the transistors T1-T5 and the storage capacitor C are shared by multiple sub-pixels. Among them, T1 is an initialization transistor, T2 is a writing transistor, T3 is a driving transistor, T4 is a compensation transistor, and T5 is a first light-emitting control transistor. The transistors T6-T8 are the second light-emitting control transistors corresponding to D1, D2, and D3 respectively.

[0094] As Figure 3 and Figure 7As shown, the pixel circuit 2 includes at least one driving signal output terminal, a first overlapping electrode 208, and a second overlapping electrode 209. The driving signal output terminal is used to output a driving signal to a sub-pixel. The first overlapping electrode 208 is electrically connected to the driving signal output terminal and the first comb-shaped electrode 311 respectively. The second overlapping electrode 209 is electrically connected to the first power supply line 10 or the second power supply line 20 and the second comb-shaped electrode 332 respectively.

[0095] Specifically, as Figure 7 shown, the pixel electrode includes a buffer layer 201, an active layer 202, a first gate insulating layer 203, a first gate layer, a second gate insulating layer 204, a second gate layer, a first insulating layer 205, a first source-drain electrode layer (including S1 and D1), a second insulating layer 206, a second source-drain electrode layer (including a data line 30, SD2, and the second power supply line 20), and a third insulating layer 207 that are located on the substrate 1 and stacked in sequence in a direction away from the substrate 1.

[0096] Specifically, as Figure 7 shown, the active layer 202 includes a source region 2021, a drain region 2023, and a channel region 2022 located between the source region 2021 and the drain region 2023. S1 serves as a source electrode and is connected to the source region 2021. D1 serves as a drain electrode and is connected to the drain region 2023. The data line 30 is connected to S1. D2 serves as an overlapping electrode and is connected to D1. The first gate layer includes a gate G1, and the second gate layer includes a gate line G2.

[0097] Specifically, as Figure 7 shown, the first overlapping electrode and the second overlapping electrode are located on a side of the third insulating layer 207 away from the substrate 1. The first overlapping electrode is connected to the overlapping electrode SD2, and the second overlapping electrode is connected to the second power supply line 20.

[0098] It should be noted that the driving substrate provided in this embodiment may also include only one gate layer and one source-drain electrode layer.

[0099] Based on the same inventive concept, this embodiment also provides a display panel. As Figures 10 to 12 shown, the display panel includes the driving substrate in the above embodiment and has the effective effects of the driving substrate in the above embodiment, which will not be elaborated here.

[0100] As Figures 10 to 12As shown in the figure, the display panel provided in this embodiment further includes a light-emitting layer 7 and a color conversion layer 8. The light-emitting layer 7 includes a plurality of light-emitting units 71 located within the openings. The light-emitting unit 71 includes a plurality of randomly distributed micro light-emitting diodes 711 located within the same opening. When the two poles of the micro light-emitting diode 711 are electrically connected to the first electrode structure 3 and the second electrode structure 3 respectively, the micro light-emitting diode 711 can be lit. The color conversion layer 8 includes a plurality of color conversion units. Each color conversion unit is located within one opening and on the side of the light-emitting layer 7 away from the driving substrate. The color conversion unit includes a first color conversion unit 81, a second color conversion unit 82, and a third color conversion unit 83.

[0101] Specifically, the micro light-emitting diode 711 uses stable and long-life blue or ultraviolet gallium nitride (GaN) LED nanorods.

[0102] Specifically, the first color conversion unit 81, the second color conversion unit 82, and the third color conversion unit 83 all use quantum dot materials, and the quantum dot materials used by the first color conversion unit 81, the second color conversion unit 82, and the third color conversion unit 83 are different.

[0103] Specifically, as Figure 12 and Figure 13 shown in the figure, there are mainly three distribution methods of the micro light-emitting diodes 711. The first is that both poles of the micro light-emitting diode 711 are lapped on the second electrode layer 33. The second is that both poles of the micro light-emitting diode 711 are lapped on the first electrode layer 31. The third is that one pole of the micro light-emitting diode 711 is lapped on the first electrode layer 31 and the other pole is lapped on the second electrode layer 33.

[0104] Based on the sizes of the micro light-emitting diode 711 and the electrode structure 3, for the first and second cases, the probabilities that the two poles of the micro light-emitting diode 711 are lapped on the first electrode structure 3 and the second electrode structure 3 respectively are close to 100%.

[0105] Based on the sizes of the micro light-emitting diode 711 and the electrode structure 3, for the third case, if one pole of the micro light-emitting diode 711 is lapped on the third comb-shaped electrode 331, the other pole of the micro light-emitting diode 711 may be lapped on the first comb tooth portion 3112 (cannot be lit), the third comb tooth portion 3312 (can be lit), or the gap between the first comb tooth portion 3112 and the third comb tooth portion 3312 (cannot be lit); if one pole of the micro light-emitting diode 711 is lapped on the fourth comb-shaped electrode 332, the other pole of the micro light-emitting diode 711 may be lapped on the first comb tooth portion 3112 (can be lit), the third comb tooth portion 3312 (cannot be lit), or the gap between the first comb tooth portion 3112 and the third comb tooth portion 3312 (cannot be lit). Therefore, in this case, there is still a certain probability that the micro light-emitting diode 711 can be lit.

[0106] As can be seen from the above analysis, in the display panel provided in this embodiment, the probability that the micro light-emitting diode 711 can be lit is significantly improved.

[0107] Based on the same inventive concept, this embodiment also provides a display device, as Figure 13 shown, the display device of the transistor in this embodiment includes the display panel in the above embodiment, and has the beneficial effects of the display panel in the above embodiment, which will not be elaborated here.

[0108] Such as Figure 13 shown, the display device provided in this embodiment further includes a driving chip, and it is determined that the chip is electrically connected to the display device and is used to provide a first power supply voltage and a second power supply voltage to the display panel. During the period of one frame of display picture, the voltages on the first power supply lines 10 of odd rows and the second power supply lines 20 of even rows are both the first power supply voltage, and the voltages on the second power supply lines 20 of odd rows and the first power supply lines 10 of even rows are both the second power supply voltage; during the display periods of two consecutive frames of pictures, the voltage of the first power supply line 10 of odd rows in the previous display period is the first power supply voltage, the voltage of the second power supply line 20 of even rows is the second power supply voltage, the voltage of the first power supply line 10 of odd rows in the subsequent display period is the second power supply voltage, and the voltage of the second power supply line 20 of even rows is the first power supply voltage.

[0109] In the display device provided in this embodiment, time-division driving is adopted. Therefore, in two adjacent frames, the micro light-emitting diodes with the P pole connected to the first electrode structure 3 and the N pole connected to the second electrode structure 3 emit light in the previous frame, and the micro light-emitting diodes with the N pole connected to the first electrode structure 3 and the P pole connected to the second electrode structure 3 emit light in the subsequent frame, so that the probability that the micro light-emitting diode 711 is lit exceeds 90%.

[0110] Based on the same inventive concept, this embodiment also provides a manufacturing method of a display panel, as Figure 14 shown, and in combination with Figures 11 - 12 , the manufacturing method of the display panel includes:

[0111] S1: Provide the above-mentioned driving substrate.

[0112] S2: Deposit the micro light-emitting diodes 711 on the driving substrate by means of coating or spraying to form a light-emitting layer 7, and the light-emitting layer 7 includes a plurality of light-emitting units 71 located in the openings 401, wherein the light-emitting unit 71 includes a plurality of randomly distributed micro light-emitting diodes 711 located in the same opening 401.

[0113] S3: Heat the driving substrate to melt the upper surface of the electrode structure 3 so that the two poles of the micro light-emitting diode 711 are wrapped by the melted electrode structure 3.

[0114] Specifically, heating is performed at a temperature that can melt the second conductive layer in the first electrode layer 31 and the fourth conductive layer in the second electrode layer 33, while the first conductive layer in the first electrode layer 31 and the third conductive layer in the second electrode layer 33 cannot be melted, so that the melted second conductive layer and the fourth conductive layer wrap the corresponding electrodes (P electrode and N electrode) of the micro light-emitting diode 711. To facilitate determining the heating temperature, the melting points of the second electrode layer 33 and the fourth electrode layer are the same.

[0115] S4: After the electrode structure 3 is cured and fixedly connected to the two poles of the micro light-emitting diode 711, a color conversion layer is formed by printing or patterning. The color conversion layer includes a plurality of color conversion units. Each color conversion unit is located in an opening 401, and the color conversion unit includes a first color conversion unit 81, a second color conversion unit 82, and a third color conversion unit 83.

[0116] The manufacturing method of the display panel provided in this embodiment is relatively simple, and the lighting probability of the micro light-emitting diodes 711 in the formed display panel is high.

[0117] Applying the embodiments of the present application can at least achieve the following beneficial effects:

[0118] 1) For the driving substrate, display panel, and display device provided in this embodiment, by arranging the electrode structure for electrically connecting to the micro light-emitting diode in a double layer, and a step layer is arranged between the first electrode layer and the second electrode layer. Among them, the first electrode layer includes a first comb-shaped electrode and a second comb-shaped electrode with their comb teeth arranged in a staggered manner, the second electrode layer includes a third comb-shaped electrode and a fourth comb-shaped electrode with their comb teeth arranged in a staggered manner, the third comb-shaped electrode is electrically connected to the first comb-shaped electrode, and the fourth comb-shaped electrode is electrically connected to the second comb-shaped electrode. The micro light-emitting diode can be limited within the range of the electrode structure, which is beneficial to increasing the contact probability between the two poles of the micro light-emitting diode and the electrode structure. Moreover, the double-layer staggered comb-shaped electrodes are beneficial to increasing the probability of correctly connecting the micro light-emitting diode and the electrode structure, thereby effectively increasing the lighting probability of the micro light-emitting diode.

[0119] 2) For the driving substrate, display panel, and display device provided in this embodiment, time-division driving is adopted during driving. In two adjacent frames, the micro light-emitting diodes with the P electrode connected to the first electrode structure and the N electrode connected to the second electrode structure emit light in the previous frame, and the micro light-emitting diodes with the N electrode connected to the first electrode structure and the P electrode connected to the second electrode structure emit light in the next frame, so that the lighting probability of the micro light-emitting diode exceeds 90%.

[0120] 3) The manufacturing method of the display panel provided in this embodiment is relatively simple, and the lighting probability of the micro light-emitting diodes in the formed display panel is high.

[0121] Those skilled in the art can understand that the various operations, methods, steps, measures, and solutions in the processes discussed in this application can be alternated, changed, combined, or deleted. Further, other steps, measures, and solutions in the various operations, methods, and processes discussed in this application can also be alternated, changed, rearranged, decomposed, combined, or deleted. Further, those in the prior art that have steps, measures, and solutions in the various operations, methods, and processes disclosed in this application can also be alternated, changed, rearranged, decomposed, combined, or deleted.

[0122] In the description of this application, the directions or positional relationships indicated by the words "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are exemplary directions or positional relationships based on the drawings, and are for the convenience of describing or simplifying the embodiments of this application, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application.

[0123] The terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, unless otherwise stated, the meaning of "a plurality" is two or more.

[0124] In the description of this specification, specific features, structures, materials, or characteristics can be combined in a suitable manner in any one or more embodiments or examples.

[0125] It should be understood that although the steps in the flowcharts of the drawings are shown sequentially in the direction of the arrows, the implementation order of these steps is not limited to the order indicated by the arrows. Unless clearly stated herein, in some implementation scenarios of the embodiments of this application, the steps in each process can be executed in other orders according to requirements. Moreover, some or all of the steps in each flowchart may include multiple sub-steps or multiple stages based on the actual implementation scenario. Some or all of these sub-steps or stages can be executed at the same time or at different times. In the scenario where the execution times are different, the execution order of these sub-steps or stages can be flexibly configured according to requirements, and the embodiments of this application do not limit this.

[0126] The above is only part of the implementation methods of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the technical concept of the solution of the present application, other similar implementation methods based on the technical ideas of the present application also fall within the protection scope of the embodiments of the present application.

Claims

1. A driving substrate for driving micro light-emitting diodes, comprising a substrate and a plurality of first power lines, a plurality of second power lines, a plurality of data lines and a plurality of pixel circuits located on the substrate, each pixel circuit driving at least one sub-pixel, characterized in that, The driving substrate further includes: A plurality of electrode structures located on a side of the pixel circuit away from the substrate, and the electrode structures correspond to the sub-pixels one by one. The electrode structure includes a first electrode layer, a step layer, and a second electrode layer arranged in sequence in a direction away from the substrate substrate; A pixel definition layer located on a side of the electrode structure away from the substrate substrate, provided with a plurality of openings penetrating through the pixel definition layer, and the orthographic projection of the edge of each electrode structure on the substrate substrate covers the orthographic projection of one of the openings on the substrate substrate; The first electrode layer includes a first comb-shaped electrode and a second comb-shaped electrode with comb teeth arranged in a staggered manner. The first comb-shaped electrode is electrically connected to the pixel circuit, and the second comb-shaped electrode is electrically connected to the first power line or the second power line; The step layer includes a main step and a plurality of auxiliary steps connected to the main step and located within the opening. The main step corresponds to the sub-pixel one by one. The orthographic projection of each main step on the substrate substrate covers the orthographic projection of the comb handle portion of the first comb-shaped electrode and the comb handle portion of the second comb-shaped electrode on the substrate substrate. The extending direction of the auxiliary step intersects with the extending direction of the comb teeth portion of the first comb-shaped electrode, and the width of the opening is smaller than the width of the edge step; The second electrode layer includes a third comb-shaped electrode and a fourth comb-shaped electrode with comb teeth arranged in a staggered manner. The third comb-shaped electrode is electrically connected to the first comb-shaped electrode and the extending direction of the comb handle portion is the same as the extending direction of the comb teeth portion of the first comb-shaped electrode. The fourth comb-shaped electrode is electrically connected to the second comb-shaped electrode and the extending direction of the comb handle portion is the same as the extending direction of the comb teeth portion of the second comb-shaped electrode. The comb handle portions of the third comb-shaped electrode and the fourth comb-shaped electrode are both located on the main step, and the comb teeth portions of the third comb-shaped electrode and the fourth comb-shaped electrode are both located on the auxiliary step.

2. The driving substrate according to claim 1, wherein The first electrode layer includes a first conductive layer and a second conductive layer located on a side of the first conductive layer away from the substrate substrate, and the melting point of the second conductive layer is lower than the melting point of the first conductive layer; The second electrode layer includes a third conductive layer and a fourth conductive layer located on a side of the third conductive layer away from the substrate substrate, and the melting point of the fourth conductive layer is lower than the melting point of the third conductive layer and lower than the melting point of the first conductive layer.

3. The driving substrate according to claim 2, wherein It further includes: A reflective layer located between the substrate substrate and the first conductive layer, including a plurality of reflective units, and the orthographic projection of the reflective unit on the substrate substrate covers the orthographic projection of the opening on the substrate substrate; A fourth insulating layer located between the reflective layer and the first electrode layer.

4. The driving substrate according to any one of claims 1-3, characterized in that, The widths of the comb teeth portions of the first comb-shaped electrode, the second comb-shaped electrode, the third comb-shaped electrode, and the fourth comb-shaped electrode are equal; The length of the micro light-emitting diode is d, and the width of the comb teeth portion of the first comb-shaped electrode is d1, then 25% d - 0.1 μm ≤ d1 ≤ 25% d + 0.1 μm; The distance between the comb teeth portions of the first comb-shaped electrode and the comb teeth portions of the second comb-shaped electrode is equal to d2, and the distance between the comb teeth portions of the third comb-shaped electrode and the comb teeth portions of the fourth comb-shaped electrode is equal to d2, where 80% d1 ≤ d2 ≤ 120% d1.

5. The driving substrate according to claim 4, characterized in that The widths of the shanks of the first comb-shaped electrode, the second comb-shaped electrode, the third comb-shaped electrode, and the fourth comb-shaped electrode are equal; The width of the shank of the first comb-shaped electrode is equal to the width of the main step, and the width of the main step is 5 μm to 15 μm.

6. The driving substrate according to claim 5, wherein The thickness of the step layer is h, where 50% d ≤ h ≤ 75% d; The thickness of the pixel definition layer is 2 μm to 8 μm.

7. The driving substrate according to claim 6, characterized in that, The pixel circuit includes at least one driving signal output terminal, a first overlapping electrode, and a second overlapping electrode; The driving signal output terminal is configured to output a driving signal to one of the sub-pixels; The first overlapping electrode is electrically connected to the driving signal output terminal and the first comb-shaped electrode respectively; The second overlapping electrode is electrically connected to the first power supply line or the second power supply line and the second comb respectively.

8. A display panel, characterized in that, Comprising: The driving substrate according to any one of claims 1-7; A light-emitting layer, including a plurality of light-emitting units located in the opening, where the light-emitting units include a plurality of randomly distributed micro light-emitting diodes located in the same opening, and the electrode structure includes a first electrode structure and a second electrode structure. When the two poles of the micro light-emitting diode are electrically connected to the first electrode structure and the second electrode structure respectively, the micro light-emitting diode can be lit; A color conversion layer, including a plurality of color conversion units, each of the color conversion units is located in one of the openings and on the side of the light-emitting layer away from the driving substrate, and the color conversion units include a first color conversion unit, a second color conversion unit, and a third color conversion unit.

9. A display device, characterized in that, Comprising: The display panel according to claim 8; A driving chip, electrically connected to the display device, and the driving chip provides a first power supply voltage and a second power supply voltage to the display panel; Within the period of one frame of display picture, the voltages on the first power supply lines of the odd rows and the second power supply lines of the even rows are both the first power supply voltage, and the voltages on the second power supply lines of the odd rows and the first power supply lines of the even rows are both the second power supply voltage; Within the display periods of two consecutive frames of pictures, the voltage of the first power supply line of the odd rows in the previous frame display period is the first power supply voltage, the voltage of the second power supply line of the even rows is the second power supply voltage, the voltage of the first power supply line of the odd rows in the next frame display period is the second power supply voltage, and the voltage of the second power supply line of the even rows is the first power supply voltage.

10. A method for manufacturing a display panel, characterized in that, Comprising: Providing the driving substrate according to any one of claims 1-7; Depositing micro light-emitting diodes on the driving substrate by means of coating or spraying to form a light-emitting layer, where the light-emitting layer includes a plurality of light-emitting units located in the opening, and the light-emitting units include a plurality of randomly distributed micro light-emitting diodes located in the same opening; Heat the driving substrate to melt the upper surface of the electrode structure, so that the two poles of the micro light-emitting diode are wrapped by the melted electrode structure; After the electrode structure is cured and fixedly connected to the two poles of the micro light-emitting diode, a color conversion layer is formed by printing or patterning. The color conversion layer includes a plurality of color conversion units. Each color conversion unit is located in one of the openings, and the color conversion unit includes a first color conversion unit, a second color conversion unit, and a third color conversion unit.

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