Manufacturing method of display panel, mask plate and display panel

Abstract

The application discloses a manufacturing method of a display panel, a mask and the display panel. The manufacturing method of the display panel comprises the following steps: providing a substrate; controlling an evaporation source to emit light-emitting material particles towards the substrate; when the light-emitting material particles pass through the openings of the mask, controlling the exit speed of the light-emitting material particles by the mask, and increasing the exit speed of the light-emitting material particles of at least one opening; and forming a plurality of light-emitting layers on the substrate. The mask is provided with a plurality of openings, and the distances between at least two openings and the evaporation source are not equal. The exit speed of the light-emitting material particles is controlled by the mask, so that the film thickness of the evaporation of the evaporation source at different positions is controlled in a directional manner, and the uniformity of the film thickness is improved.

Description

Technical Field

[0001] This application relates to the field of display technology, and in particular to a display panel, a method for manufacturing the same, a photomask, and the display panel. Background Technology

[0002] In OLED (Organic Light-Emitting Diode) devices, the organic light-emitting unit (OLED) is the core component, which needs to be formed through a vapor deposition process. Different colored OLEDs require separate vapor deposition steps due to differences in materials, formation location, and size. Generally, the luminescent material of the OLED needs to be deposited using a photomask. The photomask is placed close to the substrate, and channels are created on the photomask to allow the luminescent material to pass through. Areas on the photomask without channels prevent the luminescent material from passing through, thus forming a patterned luminescent material.

[0003] In this case, because the evaporation material in the channel at different distances from the evaporation source travels a different path, the emission velocity of the evaporation material in different channels is different. When controlling the evaporation time to form the thickness of the light-emitting layer, the thickness of the light-emitting layer on the substrate that is farther from the evaporation source is different from the thickness of the light-emitting layer that is closer to the evaporation source. Summary of the Invention

[0004] The purpose of this application is to provide a method for manufacturing a display panel, a photomask, and a display panel. The photomask is used to control the emission velocity of light-emitting material particles, thereby achieving directional control of the film thickness deposited at different positions of the evaporation source, thus improving the uniformity of the film thickness.

[0005] This application discloses a method for manufacturing a display panel, including the following steps:

[0006] Provide a substrate;

[0007] The evaporation source is controlled to emit luminescent material particles toward the substrate.

[0008] When the luminescent material particles pass through the openings of the mask, the emission velocity of the luminescent material particles is controlled by the mask to increase the emission velocity of the luminescent material particles through at least one opening.

[0009] Multiple light-emitting layers are formed on the substrate.

[0010] The mask has multiple openings, and at least two of the openings are not equidistant from the evaporation source.

[0011] Optionally, the mask is provided with multiple heating structures, which are arranged around the opening; the step of controlling the emission velocity of the luminescent material particles through the mask to increase the emission velocity of the luminescent material particles at least one opening when the luminescent material particles pass through the mask includes:

[0012] Each of the heating structures is controlled to perform heating;

[0013] When the luminescent material particles pass through the openings in the mask, the luminescent material particles are heated to increase their moving speed.

[0014] After the luminescent material particles in the multiple openings are raised to a preset speed, they are emitted from the openings.

[0015] The light-emitting material particles emitted from the plurality of openings have the same emission velocity; the farther the opening is from the evaporation source, the higher the heating temperature of the heating structure corresponding to the opening.

[0016] Optionally, the area surrounding the opening of the heating structure is the heating area; the greater the distance between the heating structure and the evaporation source, the larger the area of ​​the heating area of ​​the heating structure.

[0017] Optionally, the step of providing a substrate includes:

[0018] Provide a substrate;

[0019] A bottom electrode and a pixel definition layer are sequentially formed on a substrate. The pixel definition layer is provided with multiple opening regions, and the bottom electrode is exposed from the opening regions.

[0020] The step of controlling the evaporation source to emit luminescent material particles toward the substrate includes:

[0021] Provide a mask;

[0022] Align the multiple openings on the mask with the multiple opening areas on the substrate one by one;

[0023] The evaporation source is controlled to emit luminescent material particles toward the substrate.

[0024] The step of forming multiple light-emitting layers on the substrate includes:

[0025] At each of the said opening regions, a light-emitting layer is formed on the bottom electrode; wherein the multiple light-emitting layers have the same thickness.

[0026] Optionally, the step of providing a substrate further includes:

[0027] A second heating structure is formed on the side of the pixel definition layer near the opening area;

[0028] The step of forming a light-emitting layer on the bottom electrode at each of the opening regions further includes:

[0029] The second heating structure is subjected to ultrasonic heating treatment, and the luminescent material particles are heated after the second heating structure is heated.

[0030] At each of the said opening locations, the luminescent material particles form a luminescent layer on the bottom electrode.

[0031] This application also discloses a photomask for the manufacturing method of the display panel as described above. The photomask includes a photomask body, a plurality of openings disposed on the photomask body, and a plurality of heating structures disposed on the plurality of openings. The heating structures are disposed around the openings.

[0032] Optionally, the heating structure includes a resistance heating device, an electromagnetic induction heating device, or a microwave heating device; the heating structure includes a heating element and a heat insulation layer, the heating element is arranged around the opening, and the heat insulation layer is arranged around the heating element; the mask body includes a first central region, which is used to correspond to the evaporation source during the light-emitting layer process; the area of ​​the opening covered by the heating element is the heating area, and the heating area of ​​the heating element is larger the further away from the first central region.

[0033] Optionally, the heating element is longer the further away from the first central region, and the direction of the length is parallel to the depth direction of the opening.

[0034] This application also discloses a display panel formed by the above-described display panel manufacturing method. The display panel includes a substrate, a pixel definition layer disposed on the substrate, and a plurality of light-emitting units. The pixel definition layer has a plurality of opening regions, and the plurality of light-emitting units are respectively disposed in the plurality of opening regions. Adjacent light-emitting units are separated by the pixel definition layer. The light-emitting unit includes a bottom electrode, a light-emitting layer, and a top electrode. The light-emitting layer is disposed between the bottom electrode and the top electrode, and the plurality of light-emitting layers have the same thickness.

[0035] Optionally, a second heating structure is formed on the side of the pixel definition layer near the opening region; wherein, the substrate includes a second central region, which is configured to correspond to the evaporation source during the light-emitting layer fabrication process; the area of ​​the second heating structure is larger the further away from the opening region from the second central region.

[0036] In this application, the emission velocity of luminescent material particles is controlled using a photomask. By increasing the emission velocity of these particles, a sufficiently thick luminescent layer is formed at openings at different distances from the evaporation source within the evaporation time. This allows for directional control of the film thickness at different locations. Furthermore, it ensures that the film thickness at different locations remains equal, thereby improving the uniformity of the film thickness. Attached Figure Description

[0037] The accompanying drawings, which form part of the specification, are used to provide a further understanding of the embodiments of this application and illustrate the implementation methods of this application, together with the textual description, to explain the principles of this application. Obviously, the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any creative effort. In the drawings:

[0038] Figure 1 This is a schematic diagram illustrating the steps of a method for manufacturing a display panel according to the first embodiment of this application;

[0039] Figure 2 This is a schematic diagram illustrating the fabrication of the display panel according to the first embodiment of this application;

[0040] Figure 3 This is a schematic diagram of the heating structure of this application;

[0041] Figure 4 This is a schematic diagram illustrating a method for manufacturing a display panel according to another embodiment of this application. Figure 5 This is a schematic diagram of the substrate of this application;

[0042] Figure 6 This is a top view schematic diagram of a photomask of this application;

[0043] Figure 7 This is a cross-sectional schematic diagram of the display panel of this application;

[0044] Figure 8 This is a top view of the display panel of this application.

[0045] Among them, 100 is a display panel; 110 is a substrate; 111 is a pixel definition layer; 112 is a second central area; 113 is an opening area; 120 is a light-emitting unit; 121 is a bottom electrode; 122 is a light-emitting layer; 123 is a top electrode; 130 is a second heating structure; 200 is a mask; 210 is a mask body; 211 is a first mask; 212 is a second mask; 213 is a first central area; 214 is a mesh; 220 is an opening; 230 is a heating structure; 231 is a heating element; 232 is a heat insulation layer; and 300 is an evaporation source. Detailed Implementation

[0046] It should be understood that the terminology, specific structural and functional details used herein are merely for describing particular embodiments and are representative. However, this application may be implemented in many alternative forms and should not be construed as being limited to the embodiments set forth herein.

[0047] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating relative importance or implying the number of technical features indicated. Therefore, unless otherwise stated, a feature specified as "first" or "second" may explicitly or implicitly include one or more of that feature; "multiple" means two or more. Furthermore, terms such as "upper," "lower," "left," "right," "vertical," and "horizontal," indicating orientation or positional relationships, are based on the orientation or relative positional relationships shown in the accompanying drawings and are only for the purpose of simplifying the description of this application, not indicating that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting this application. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0048] The present application will now be described in detail with reference to the accompanying drawings and optional embodiments.

[0049] Figure 1 This is a schematic diagram illustrating the steps of a method for manufacturing a display panel according to the first embodiment of this application. Figure 2 This is a schematic diagram of the manufacturing process of the display panel according to the first embodiment of this application. See also: Figures 1 to 2 As shown, this application discloses a method for manufacturing a display panel, including the following steps:

[0050] S10: Provides a substrate;

[0051] S20: Control the evaporation source to emit luminescent material particles toward the substrate;

[0052] S30: When the luminescent material particles pass through the opening of the mask, the emission speed of the luminescent material particles is controlled by the mask to increase the emission speed of the luminescent material particles through at least one opening.

[0053] S40: A plurality of light-emitting layers are formed on the substrate;

[0054] The mask has multiple openings, and at least two of the openings are not equidistant from the evaporation source.

[0055] In this application, the emission velocity of luminescent material particles is controlled using a photomask. By increasing the emission velocity of these particles, a sufficiently thick luminescent layer is formed at openings at different distances from the evaporation source within the evaporation time. This allows for directional control of the film thickness at different locations. Furthermore, it ensures that the film thickness at different locations remains equal, thereby improving the uniformity of the film thickness.

[0056] Specifically, step S10 also includes:

[0057] S101: A substrate is provided, which can be a flexible substrate or a non-flexible substrate. Before the fabrication process of the light-emitting unit, a pixel driving layer is generally formed on the substrate. This pixel driving layer typically has multiple thin-film transistors and various signal lines, thereby forming a pixel driving circuit that drives each light-emitting unit to emit light. After the pixel driving layer fabrication process is completed, the light-emitting unit fabrication process begins.

[0058] S102: A bottom electrode and a pixel definition layer are sequentially formed on a substrate. The pixel definition layer is provided with multiple opening regions, and the bottom electrode is exposed from the opening regions.

[0059] The light-emitting unit typically includes a bottom electrode, a light-emitting layer, and a top electrode. The light-emitting layer is located between the bottom and top electrodes. By applying different voltage signals to the bottom electrode, different brightness levels of the light-emitting layer are achieved. This bottom electrode is also typically connected to a pixel driving circuit located in the pixel driving layer, acquiring corresponding display signals via data lines.

[0060] It is understood that the main steps involved in the manufacturing method of the display panel in this application are the fabrication of the light-emitting layer. After the light-emitting layer is formed, the process also includes forming a top electrode, thereby forming multiple light-emitting units on the substrate. After completing the fabrication of the light-emitting units, a packaging process is often required to form the display panel. Other processes have not been specifically improved in this application and will not be described in detail here.

[0061] Step S20 includes:

[0062] S201: Provides a photomask;

[0063] S202: Align the multiple openings on the mask with the multiple opening areas on the substrate one by one;

[0064] S203: Control the evaporation source to emit luminescent material particles toward the substrate;

[0065] The photomask in this embodiment is generally a metal photomask, also known as a fine metal photomask. By setting multiple openings on the photomask, the vapor-deposited material emitted from the evaporation source can pass through the openings but cannot pass through the non-opening areas, thereby forming a patterned film layer. For example, the luminescent material particles in this embodiment, after passing through the openings, directly enter the opening area and form a luminescent layer on the bottom electrode. Moreover, the luminescent layer in each opening area is independently set and is a patterned luminescent layer.

[0066] Specifically, this application provides multiple heating structures on a photomask, which surround the opening, and uses these heating structures to control the emission velocity of the luminescent material particles within the corresponding opening.

[0067] The evaporation process used in this application for the light-emitting layer is vacuum evaporation. In a vacuum environment, the light-emitting material is heated, vaporized, and deposited onto a substrate to obtain a thin film material as the light-emitting layer. Generally, the quality of the light-emitting material determines the performance of the display panel, while the quality of the evaporation source determines the effectiveness of the light-emitting layer evaporation. Both play a decisive role in the yield, quality, and lifespan of the display panel.

[0068] Taking luminescent materials as an example, during the evaporation process, the movement of the evaporated luminescent material particles exhibits a clear directionality. Furthermore, the directionality of this particle movement significantly impacts the uniformity of the deposited thin film. Currently, evaporation sources can be broadly categorized into point evaporation sources and surface evaporation sources. Generally, evaporation sources that are relatively far from the substrate and have a small size can be considered point evaporation sources. Surface evaporation sources consist of a small hole with a very small diameter at the top of a high-temperature crucible. Inside the crucible, the vapor pressure of the luminescent material is approximately equal to its equilibrium vapor pressure, while outside the crucible, a high vacuum is maintained. Due to its smaller effective evaporation area, surface evaporation sources have a lower evaporation rate, but their evaporation beam exhibits better directionality.

[0069] In this embodiment, the luminescent material particles emitted by the defined evaporation source are uniformly distributed, meaning that the number of luminescent material particles reaching each opening is equal. However, due to the different distances between the multiple openings and the evaporation source, on the one hand, the greater the distance, the greater the velocity attenuation of the luminescent material particles; on the other hand, the longer the distance, the longer the time it takes for the luminescent material particles to reach the evaporation source. Within the same time frame, the openings farther from the evaporation source will have less luminescent material passing through, ultimately resulting in a thinner luminescent layer. Therefore, this application controls the velocity of the luminescent material particles so that, when the luminescent material particles emitted by the evaporation source are uniformly distributed, the luminescent material particles emitted from the mask at different positions have the same velocity, opening the evaporation source within the same time frame, thus ensuring that the film thickness at different positions is the same.

[0070] However, in reality, the luminescent material particles emitted from the evaporation source are not completely uniform. When the uniformity is poor, the emission velocity of the luminescent material particles at locations with lower emission levels can be controlled to increase, even exceeding, the emission velocity at other opening locations. This results in a higher emission velocity at locations with lower emission levels, leading to a film thickness per unit time comparable to that formed by openings with relatively lower emission velocities, thereby improving the uniformity of the luminescent layer.

[0071] Specifically, step S30 includes:

[0072] S301: Control the multiple heating structures to perform heating respectively;

[0073] S302: When the luminescent material particles pass through the opening of the mask, the luminescent material particles are heated to increase their moving speed;

[0074] S303: The luminescent material particles in the plurality of openings are raised to a preset speed and then emitted from the openings.

[0075] In this embodiment, the heating structure is mainly used to heat the openings, causing the temperature inside the openings to rise. Increased temperature leads to faster gas molecule movement, thereby increasing gas velocity and flow rate. Conversely, decreased temperature reduces gas velocity and flow rate. Therefore, by raising the temperature inside the openings, the emission velocity of the luminescent material particles is controlled. Utilizing the different gas flow rates at different temperatures, the thickness of the vapor-deposited film at different locations within the same time frame is controlled, thus directionally controlling the film thickness deposited at different locations by the evaporation source, improving the uniformity and consistency of the film thickness. Taking the fabrication process of the luminescent layer as an example, the luminescent material particles represent the aforementioned vapor-deposited gas. Ideally, the emission velocity of the luminescent material particles from multiple openings within the mask is the same, thereby ensuring consistent luminescent layer thickness in each opening region within the same vapor deposition time.

[0076] Specifically, the greater the distance between the opening and the evaporation source, the higher the heating temperature of the heating structure corresponding to the opening. Generally, the farther the opening is from the evaporation source, the farther the luminescent material particles travel, and the faster they need to travel. This embodiment designs the heating temperature at different locations through the heating structure, so that the intensity of acceleration of the luminescent material particles in different openings varies, ultimately achieving uniform thickness of the luminescent layer.

[0077] In one specific embodiment, considering the complexity of controlling the heating structures within different openings to reach different temperatures, the method involves individual control of each heating structure within each opening, leading to significant practical control difficulties. Therefore, in this embodiment, all heating structures can be controlled uniformly by varying the heating area at different locations, thereby enabling individual temperature control within each opening.

[0078] The area surrounding the opening of the heating structure is the heating area; the greater the distance between the heating structure and the evaporation source, the larger the area of ​​the heating area of ​​the heating structure.

[0079] In this embodiment, by controlling the area of ​​the heating region, on the one hand, a larger heating area is used to heat the luminescent material particles, resulting in a greater temperature increase. On the other hand, increasing the heating area also increases the heating time of the luminescent material particles as they pass through the opening, thereby increasing the particle velocity. Furthermore, by controlling the area of ​​the heating structures at different locations to be different, multiple heating structures can be controlled simultaneously or individually. Multiple heating structures can be connected in parallel and controlled by a single heating control signal. When the luminescent layer process is completed, the power is cut off to shut down the heating structure.

[0080] Figure 3 This is a schematic diagram of the heating structure of this application, see below. Figure 3 As shown, in this embodiment, the heating temperature in each opening is the same, but the channel length of the heating temperature is different, and the acceleration time is also different, thereby achieving individual acceleration in multiple openings.

[0081] Furthermore, the heating structure is arranged around the opening, with varying lengths L at different opening positions. The length of this heating structure is parallel to the direction of emission of the luminescent material particles, i.e., parallel to the depth direction of the opening. By completely surrounding the opening but not fully covering its sides, the heating temperature within the opening is made more uniform, and the heating area at different locations can be varied by controlling the length L of the heating structure.

[0082] Of course, in another embodiment, the heating structure corresponding to each opening can be individually controllable. By making the heating structure completely cover the opening, the heating structure can be controlled to heat to different temperatures, so that the opening farther away from the evaporation source has a relatively large heating temperature, and the opening closer to the evaporation source has a relatively small heating temperature, thereby accelerating the luminescent material particles inside the opening.

[0083] It is understandable that in order to accelerate the luminescent material particles, the heating temperature generally needs to be higher than the ambient temperature when the luminescent material particles move from the evaporation source into the mask opening, thereby increasing the emission speed of the luminescent material particles by raising the temperature of the opening.

[0084] Specifically, the steps in S40 include:

[0085] S401: At each of the said opening regions, a light-emitting layer is formed on the bottom electrode; wherein the multiple light-emitting layers have the same thickness.

[0086] Taking a display panel with three primary colors as an example, a single pixel typically contains three sub-pixels, composed of red, green, and blue light-emitting units. Each color of light-emitting unit corresponds to a sub-pixel of that color, such as red, green, and blue sub-pixels. The difference in manufacturing process between different colored light-emitting units lies in the materials used in the light-emitting layer. For example, a red light-emitting unit generally requires a red light-emitting material to form the light-emitting layer to emit red light. Similarly, a green light-emitting unit uses a green light-emitting material, and a blue light-emitting unit uses a blue light-emitting material.

[0087] For display panels with equal sub-pixel areas, a single photomask can be used to form the light-emitting parts of each light-emitting unit. This means multiple openings are formed on the photomask, the number of which equals one-third the number of sub-pixels. Specifically, these openings correspond to multiple red sub-pixels, multiple green sub-pixels, or multiple blue sub-pixels. In the process, red light-emitting units are first formed using the photomask. Then, the photomask is moved so that its channels correspond to green sub-pixel areas, thus forming green light-emitting units. The photomask is moved again so that its channels correspond to blue sub-pixel areas, thus forming blue light-emitting units. This process is repeated three times to form red, green, and blue light-emitting units respectively.

[0088] For display panels with subpixel areas of varying sizes, it is generally necessary to set separate masks for subpixels of different colors. For example, a red pixel mask with a channel the size of the red subpixel arrangement is set for the red subpixel position. Similarly, a green pixel mask is set for the green subpixel, and a blue pixel mask is set for the blue subpixel.

[0089] Figure 4 This is a schematic diagram illustrating a method for manufacturing a display panel according to another embodiment of this application. Figure 5 This is a schematic diagram of the substrate of this application, see below. Figures 4 to 5As shown, based on the above embodiment, a heating step is further added to improve the uniformity of the film layer in each opening area, thereby balancing the particle quantity differences caused by uneven heating in the middle and edges of each opening. The method for manufacturing the display panel includes the following steps:

[0090] S101: Provides a substrate;

[0091] S102: A bottom electrode and a pixel definition layer are sequentially formed on a substrate, wherein the pixel definition layer is provided with a plurality of opening regions, and the bottom electrode is exposed from the opening regions;

[0092] S103: A second heating structure is formed on the side of the pixel definition layer near the opening area;

[0093] S20: Control the evaporation source to emit luminescent material particles toward the substrate;

[0094] S30: When the luminescent material particles pass through the opening of the mask, the emission speed of the luminescent material particles is controlled by the mask to increase the emission speed of the luminescent material particles through at least one opening.

[0095] S401: The second heating structure is subjected to ultrasonic heating treatment, and the luminescent material particles are heated after the second heating structure is heated.

[0096] S402: At each of the said opening regions, the luminescent material particles form a luminescent layer on the bottom electrode;

[0097] S403: Forms a light-emitting unit.

[0098] In this embodiment, based on the previous embodiment, since the temperature range within a single opening is prone to unevenness between the middle and edge regions, the light-emitting layer film in each opening area is relatively uneven. To address this, this embodiment also provides a second heating structure. This second heating structure is formed using a microwave-absorbing material. By damping vibration or internal friction under the action of ultrasound, the mechanical energy of the ultrasound is converted into heat energy to generate heat, which heats the light-emitting material particles passing through the opening area, thereby balancing the differences in film thickness at different locations, and thus making the light-emitting layer film in each opening area more uniform.

[0099] In steps S20 to S30, the same as in the above embodiments can be used, or any embodiment can be selected for implementation. It is understood that the ultrasonic frequency provided by the second heating structure and the control provided by the heating structure can be adjusted according to actual conditions. In actual testing, by changing the heating area of ​​the heating structure at different positions, parameters for a more uniform luminescent film can be adjusted.

[0100] Figure 6This is a top view schematic diagram of a photomask of this application, combined with... Figure 2 , 3 and Figure 6 As shown, this application discloses a mask 200 used in the above-described method for manufacturing a display panel. Specifically, the mask 200 includes a mask body 210, a plurality of openings 220 disposed on the mask body 210, and a plurality of heating structures 230 disposed on the plurality of openings 220; the heating structures 230 are disposed around the openings 220.

[0101] In this embodiment, by setting multiple heating structures 230 on the mask body 210, with each heating structure 230 surrounding each opening 220, the luminescent material particles inside the opening 220 are heated by the heating structures 230, thereby increasing the emission speed of the luminescent material particles.

[0102] The heating structure 230 includes resistance heating devices, electromagnetic induction heating devices, or microwave heating devices.

[0103] Specifically, the heating structure 230 includes a heating element 231 and a heat insulation layer 232. The heating element 231 is disposed around the opening 220, and the heat insulation layer 232 is disposed around the heating element 231. In this embodiment, the heat insulation layer 232 is used to prevent temperature interference between adjacent openings 220, so that the temperature in each opening 220 can only be controlled by the heating element 231 disposed around the opening 220.

[0104] The mask body 210 includes a first central region 213, which is configured to correspond with the evaporation source 300 during the light-emitting layer process. The area covered by the heating element 231 and the opening 220 is the heating area, and the heating area of ​​the heating element 231 is larger the further away from the first central region 213 it is.

[0105] In this embodiment, TS (Target-Source Distance) in the evaporation source 300 refers to the distance from the evaporation source 300 to the mask 200. The TS distance is generally between 400nm and 800nm. When the TS distance is small, the utilization rate of the luminescent material particles is high, the pixel PPI is small, but the film uniformity is poor, and the SD (Shadow Distance) is large. When the TS distance is large, the film uniformity changes, the SD becomes smaller, but the material utilization rate is low, and the PPI is large. Different distances and positions from the same evaporation source 300 to each opening 220 will result in differences in the thickness of the vapor-deposited film, which can seriously affect the luminescence lifespan and the lifespan of the display panel.

[0106] Therefore, in this embodiment, by making the heating area of ​​the heating element 231 that is further away from the first central region 213 larger, the heating area of ​​the opening 220 that is further away from the evaporation source 300 is larger, that is, the heating channel is longer, so that the luminescent material particles have a stronger acceleration ability when passing through, thereby increasing the thickness of the luminescent layer in the opening area corresponding to the opening 220.

[0107] Specifically, the size of the heating area in this embodiment is achieved by adjusting the length of the heating element 231. The heating element 231 is longer the further away from the first central region 213, and the direction of this length is parallel to the depth direction of the opening 220. Specifically, taking the opening 220 as a circular channel as an example, the heating element 231 surrounding the channel of the opening 220 is a hollow cylinder, and the height of the cylinder is the length of the heating element 231 mentioned in this application. By controlling the length of the heating element 231, the length of the heated channel increases when the luminescent material particles pass through the opening 220, thereby increasing the emission velocity of the heated luminescent material particles.

[0108] The depth of the aperture 220 is related to the thickness of the mask 200. When the mask 200 is thin, the depth of the aperture 220 is also limited, resulting in a limited heating area for the heating element 231. In this case, the thickness of the mask 200 can be increased to improve the depth of the aperture 220.

[0109] In one embodiment, the mask body 210 includes a first mask 211 and a second mask 212, with a gap between them. Multiple mesh openings 214 are formed on both the first and second masks 211 and 212, respectively. The shape of the mesh openings 214 is not limited and can be changed according to the actual pixel design, thereby forming an opening 220 channel through which luminescent material particles pass. A heating element 231 is arranged around the opening 220 channel, sandwiched between the first and second masks 211 and 212. By controlling the size of the gap, the depth of the opening 220 channel, i.e., the channel depth through which luminescent material particles pass, is controlled.

[0110] Figure 7 This is a cross-sectional schematic diagram of the display panel of this application. Figure 8 This is a top view of the display panel 100 of this application, see below. Figures 2 to 8 As shown, this application also discloses a display panel 100, which can be formed using the manufacturing method of the display panel 100 in any of the above embodiments.

[0111] The display panel 100 includes a substrate 110, a pixel definition layer 111 disposed on the substrate 110, and a plurality of light-emitting units 120. The pixel definition layer 111 is provided with a plurality of opening areas 113, and the plurality of light-emitting units 120 are respectively disposed in the plurality of opening areas 113. Two adjacent light-emitting units 120 are separated by the pixel definition layer 111. The light-emitting unit 120 includes a bottom electrode 121, a light-emitting layer 122, and a top electrode 123. The light-emitting layer 122 is disposed between the bottom electrode 121 and the top electrode 123, and the plurality of light-emitting layers 122 have the same thickness.

[0112] In this application, by controlling the emission velocity of luminescent material particles using a photomask, and thereby increasing the emission velocity of the luminescent material particles, a sufficiently thick luminescent layer 122 is formed in the openings at different distances from the evaporation source within the evaporation time. This achieves directional control of the film thickness at different locations of the evaporation source. Furthermore, it ensures that the film thickness at different locations remains equal, thereby improving the uniformity of the film thickness.

[0113] In a specific embodiment corresponding to the use of the second heating structure 130 described above, the second heating structure 130 is formed on the side of the pixel definition layer 111 near the opening area 113. The second heating structure 130 is formed of a wave-absorbing material. The second heating structure is formed of a wave-absorbing material, which converts the mechanical energy of the ultrasonic wave into heat energy by damping vibration or internal friction under the action of ultrasonic waves to generate heat, thereby heating the light-emitting material particles passing through the opening area 113, thereby balancing the difference in film thickness at different positions, and making the light-emitting layer 122 film layer in each opening area 113 more uniform.

[0114] The substrate 110 includes a second central region 112, which is configured to correspond to the evaporation source during the fabrication of the light-emitting layer 122. The area of ​​the second heating structure 130 is larger the further away from the opening region 113 from the second central region 112. In this embodiment, the second heating structure 130 can be used in conjunction with the aforementioned heating structure. During testing, by changing the area of ​​the second heating structure 130 at different positions, the heating area of ​​the heating structure, or the heating temperature, parameters that make the corresponding light-emitting layer 122 film more uniform can be adjusted.

[0115] It should be noted that the inventive concept of this application can form many embodiments, but due to the limited space of the application documents, they cannot all be listed. Therefore, without conflict, the embodiments described above or the technical features can be arbitrarily combined to form new embodiments. After the embodiments or technical features are combined, the original technical effect will be enhanced.

[0116] The above description, in conjunction with specific optional embodiments, provides a further detailed explanation of this application and should not be construed as limiting the specific implementation of this application to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of this application, and all such modifications or substitutions should be considered within the scope of protection of this application.

Claims

1. A method for manufacturing a display panel, characterized in that, Including the following steps: Provide a substrate; The evaporation source is controlled to emit luminescent material particles toward the substrate. When the luminescent material particles pass through the openings of the mask, the emission velocity of the luminescent material particles is controlled by the mask to increase the emission velocity of the luminescent material particles through at least one opening. Multiple light-emitting layers are formed on the substrate. The photomask has multiple openings, and at least two of the openings are not equidistant from the evaporation source. The mask is provided with multiple heating structures, which are arranged around the opening; The step of controlling the emission velocity of the luminescent material particles through the mask when the luminescent material particles pass through the mask, and increasing the emission velocity of the luminescent material particles through at least one opening, includes: Each of the heating structures is controlled to perform heating; When the luminescent material particles pass through the openings in the mask, the luminescent material particles are heated to increase their moving speed. After the luminescent material particles in the multiple openings are raised to a preset speed, they are emitted from the openings. The light-emitting material particles emitted from the plurality of openings have the same emission velocity; the farther the opening is from the evaporation source, the higher the heating temperature of the heating structure corresponding to the opening.

2. The method for manufacturing a display panel according to claim 1, characterized in that, The area surrounding the opening is the heating zone; The greater the distance between the heating structure and the evaporation source, the larger the area of ​​the heating region of the heating structure.

3. The method for manufacturing a display panel according to claim 1, characterized in that, The step of providing a substrate includes: Provide a substrate; A bottom electrode and a pixel definition layer are sequentially formed on a substrate. The pixel definition layer is provided with multiple opening regions, and the bottom electrode is exposed from the opening regions. The step of controlling the evaporation source to emit luminescent material particles toward the substrate includes: Provide a mask; Align the multiple openings on the mask with the multiple opening areas on the substrate one by one; The evaporation source is controlled to emit luminescent material particles toward the substrate. The step of forming multiple light-emitting layers on the substrate includes: At each of the said opening regions, a light-emitting layer is formed on the bottom electrode; wherein the multiple light-emitting layers have the same thickness.

4. The method for manufacturing a display panel according to claim 3, characterized in that, The step of providing a substrate further includes: A second heating structure is formed on the side of the pixel definition layer near the opening area; The step of forming a light-emitting layer on the bottom electrode at each of the opening regions further includes: The second heating structure is subjected to ultrasonic heating treatment, and the luminescent material particles are heated after the second heating structure is heated. At each of the said opening locations, the luminescent material particles form a luminescent layer on the bottom electrode.

5. A photomask, characterized in that, The method for manufacturing a display panel as described in any one of claims 1 to 4, wherein the mask includes a mask body, a plurality of openings disposed on the mask body, and a plurality of heating structures disposed in the plurality of openings; the heating structures are disposed around the openings.

6. The photomask according to claim 5, characterized in that, The heating structure includes a resistance heating device, an electromagnetic induction heating device, or a microwave heating device; The heating structure includes a heating element and a heat insulation layer, wherein the heating element is disposed around the opening and the heat insulation layer is disposed around the heating element; The mask body includes a first central region, which is configured to correspond with the evaporation source during the light-emitting layer fabrication process; The area covered by the heating element and the opening is the heating area, and the heating area of ​​the heating element is larger the further away from the first central area.

7. The photomask according to claim 6, characterized in that, The heating element is longer the further away from the first central area, and the direction of the length is parallel to the depth direction of the opening.

8. A display panel, characterized in that, The display panel is formed by the manufacturing method of the display panel as described in any one of claims 1-4. The display panel includes a substrate, a pixel definition layer disposed on the substrate, and a plurality of light-emitting units. The pixel definition layer is provided with a plurality of opening areas, and the plurality of light-emitting units are respectively disposed in the plurality of opening areas. Two adjacent light-emitting units are separated by the pixel definition layer. The light-emitting unit includes a bottom electrode, a light-emitting layer, and a top electrode. The light-emitting layer is disposed between the bottom electrode and the top electrode, and the multiple light-emitting layers have the same thickness.

9. The display panel according to claim 8, characterized in that, A second heating structure is formed on the side of the pixel definition layer near the opening area; The substrate includes a second central region, which is configured to correspond to the evaporation source during the light-emitting layer fabrication process; the area of ​​the second heating structure is larger the further away from the opening region of the second central region.

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