Display panel and display device
By setting an ink buffer structure on the bottom electrode, the problem of ink climbing during inkjet printing is solved, and the effect of preventing pollution and improving trust is achieved.
Patent Information
- Application Number
- CN202510153060.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-11
- Publication Date
- 2025-05-30
AI Technical Summary
Before inkjet printing to form film, ink climbing is likely to form an edge of the pixel definition layer, causing ink to overflow into adjacent pixel areas, causing pollution problems.
By providing an ink buffer structure on the side of the bottom electrode close to the pixel definition layer, ink is blocked from flowing to the pixel definition layer, and ink is prevented from climbing slopes. The buffer structure may be a buffer dam or buffer channel, which is realized by adjusting the shape or structure of the bottom electrode.
It effectively prevents ink from climbing up the pixel definition layer, reduces pollution, improves the reliability of the display panel, and ensures the effective luminous area of the luminous emitting unit.
Smart Images
Figure CN120076586A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of display technologies, and particularly to a display panel and a display device. Background Art
[0002] Organic light emitting diodes (OLEDs) have become increasingly mature in mass production technology due to advantages such as surface light sources, cold light, energy saving, fast response, flexibility, ultra-thinness, and low cost. Usually, the light-emitting unit of an OLED is composed of thin films of three light-emitting colors, RGB. During the preparation of the three-color light-emitting thin films, a patterning process is required. Inkjet printing, as a non-contact patterning technology, can directly pattern by ejecting ink droplets to designated positions on a substrate. The hole injection layer, hole transport layer, and light-emitting layer are often formed by printing, and then the electron transport layer, cathode, etc. are prepared by a non-metal mask patterning method.
[0003] However, before inkjet printing to form a film, it is usually necessary to prepare openings with a pixel definition layer (PDL) to form sub-pixel regions. Ink is likely to form a slope at the edge part of the pixel definition layer, and in severe cases, it even overflows to adjacent pixels, resulting in contamination problems. Summary of the Invention
[0004] The purpose of the present application is to provide a display panel and a display device. By providing an ink buffer structure, when inkjet printing is performed on the light-emitting layer using the ink buffer structure, ink is prevented from climbing up onto the pixel definition layer, thereby improving the reliability of the display panel.
[0005] The present application discloses a display panel, including a substrate, a plurality of pixel definition layers, and a plurality of light-emitting units. The plurality of pixel definition layers are formed on the substrate, and sub-pixel regions are formed between adjacent two pixel definition layers; the plurality of light-emitting units are respectively disposed in the plurality of sub-pixel regions; wherein, the light-emitting unit includes a bottom electrode and a light-emitting functional layer, the bottom electrode is disposed on the substrate, and the light-emitting functional layer is configured to be formed on the bottom electrode by inkjet printing; an ink buffer structure is formed on at least one side of the bottom electrode close to the pixel definition layer, and the ink buffer structure is configured to prevent ink from climbing up onto the pixel definition layer when inkjet printing is performed on the light-emitting functional layer.
[0006] Optionally, the ink buffer structure includes a buffer dam, the bottom electrode extends towards the pixel definition layer to form the buffer dam, and the surface of the buffer dam away from the substrate is higher than the surface of the bottom electrode away from the substrate; the buffer dam is configured to prevent ink from climbing up onto the pixel definition layer when inkjet printing is performed on the light-emitting functional layer.
[0007] Optionally, the display panel further includes a pixel driving layer and a planarization layer. The pixel driving layer is disposed on the substrate, and the planarization layer is disposed on the pixel driving layer. The planarization layer is provided with a protrusion, which is disposed between the pixel defining layer and the bottom electrode. And under the orthographic projection on the substrate, the protrusion overlaps with the buffer dam. Wherein, the buffer dam and the bottom electrode are formed in a synchronous process, and the protrusion is used to make the surface of the buffer dam away from the substrate higher than the surface of the bottom electrode away from the substrate.
[0008] Optionally, the height difference between the surface of the buffer dam away from the substrate and the surface of the bottom electrode away from the substrate is between 0.5 μm and 1 μm.
[0009] Optionally, the ink buffer structure includes a buffer channel. An extension portion is provided in the extending direction of the bottom electrode towards the pixel defining layer. The surface of the extension portion away from the substrate is lower than the surface of the bottom electrode away from the substrate. The pixel defining layer, the extension portion and the side surface of the bottom electrode higher than the extension portion form the buffer channel, which is used to prevent ink from climbing onto the pixel defining layer when inkjet printing is performed on the light-emitting functional layer.
[0010] Optionally, the display panel further includes a pixel driving layer and a planarization layer. The pixel driving layer is disposed on the substrate, and the planarization layer is disposed on the pixel driving layer. The planarization layer is provided with a groove, which overlaps with the extension portion under the orthographic projection on the substrate. The bottom electrode and the extension portion are formed in a synchronous process, and the groove is used to make the surface of the extension portion away from the substrate lower than the surface of the bottom electrode away from the substrate.
[0011] Optionally, the width of the buffer channel is between 0.5 μm and 1 μm.
[0012] Optionally, the sub-pixel region includes any one of a red sub-pixel region, a green sub-pixel region or a blue sub-pixel region. An ink buffer structure is provided between two adjacent sub-pixel regions of different colors. No ink buffer structure is provided between two adjacent sub-pixel regions of the same color.
[0013] Optionally, a receiving groove is further provided on the pixel defining layer, which is used to store ink when the ink flows over the pixel defining layer towards the adjacent sub-pixel region during inkjet printing of the light-emitting functional layer.
[0014] The present application also discloses a display device, including a driving circuit and the above-mentioned display panel, wherein the driving circuit is used to drive the display panel to display.
[0015] In the present application, when the bottom electrode is formed, an ink buffer structure is provided on one side of the bottom electrode close to the pixel defining layer. The ink buffer structure mainly blocks the ink flow towards the pixel defining layer to reduce the ink climbing problem caused by the hydrophilicity between the ink and the pixel defining layer. Compared with the solution of directly converting the pixel defining layer into a hydrophobic material to prevent ink climbing, the present application improves the shape or structure of the bottom electrode, thereby avoiding the need for complex material improvement of the pixel defining layer and the reduction of the effective light-emitting area of the light-emitting unit caused by the improvement of the pixel defining layer. In the present application, the bottom electrode extends towards the pixel defining layer to form an ink buffer structure, and the ink buffer structure can actually still drive the upper light-emitting functional layer to emit light, so as to ensure the effective light-emitting area of the light-emitting unit while preventing ink climbing. Description of the Drawings
[0016] The accompanying drawings included are used to provide a further understanding of the embodiments of the present application, which form a part of the specification, are used to illustrate the embodiments of the present application, and are used to explain the principles of the present application together with the written description. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts. In the drawings:
[0017] Figure 1 is a schematic diagram of the display panel of the present application;
[0018] Figure 2 is a schematic diagram of the display panel of the first embodiment of the present application;
[0019] Figure 3 is Figure 2 a partial enlarged schematic diagram of;
[0020] Figure 4 is a schematic diagram of the display panel of the second embodiment of the present application;
[0021] Figure 5 is Figure 4 a partial enlarged schematic diagram of;
[0022] Figure 6 is a schematic diagram of the display panel of the third embodiment of the present application;
[0023] Figure 7 is Figure 6 a partial enlarged schematic diagram of;
[0024] Figure 8 is a top view schematic diagram of the display panel of the present application;
[0025] Figure 9Schematic diagram of a display panel according to another embodiment of the present application;
[0026] Figure 10 Schematic diagram of a display device according to the present application.
[0027] Wherein, 100 is the display panel; 101 is the sub-pixel area; 101R is the red sub-pixel area; 101G is the green sub-pixel area; 101B is the blue sub-pixel area; 110 is the substrate; 111 is the pixel driving layer; 112 is the pixel defining layer; 1121 is the accommodating groove; 120 is the planarization layer; 121 is the protrusion; 122 is the groove; 130 is the light-emitting unit; 131 is the bottom electrode; 1311 is the extension; 1312 is the wiring segment; 132 is the light-emitting functional layer; 140 is the ink buffer structure; 141 is the buffer dam; 142 is the buffer channel; 200 is the display device; 210 is the driving circuit. Detailed implementation manners
[0028] It should be understood that the terms, the specific structures and functional details disclosed herein are only for the purpose of describing specific embodiments, which are representative, but the present application can be specifically implemented in many alternative forms and should not be construed as being limited only to the embodiments set forth herein.
[0029] In the description of the present application, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating relative importance or implicitly indicating the number of the indicated technical features. Thus, unless otherwise specified, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features; the meaning of "plurality" is two or more. In addition, the terms indicating the orientation or positional relationship such as "upper", "lower", "left", "right", "vertical", "horizontal", etc. are described based on the orientation or relative positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, rather than indicating that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation to the present application. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.
[0030] The present application will be described in detail below with reference to the accompanying drawings and optional embodiments.
[0031] Figure 1 Schematic diagram of the display panel according to the present application, see Figure 1As shown in the figure, the present application discloses a display panel. The display panel 100 includes a substrate 110, a plurality of pixel definition layers 112, and a plurality of light-emitting units 130. The plurality of pixel definition layers 112 are formed on the substrate 110, and a sub-pixel region 101 is formed between two adjacent pixel definition layers 112. The plurality of light-emitting units 130 are respectively disposed in the plurality of sub-pixel regions 101. Among them, the light-emitting unit 130 includes a bottom electrode 131 and a light-emitting functional layer 132. The bottom electrode 131 is disposed on the substrate 110, and the light-emitting functional layer 132 is formed on the bottom electrode 131 by inkjet printing. An ink buffer structure 140 is formed on at least one side of the bottom electrode 131 close to the pixel definition layer 112. The ink buffer structure 140 is used to prevent ink from climbing onto the pixel definition layer 112 during inkjet printing of the light-emitting functional layer 132.
[0032] In the present application, when the bottom electrode 131 is formed, an ink buffer structure 140 is provided on one side of the bottom electrode 131 close to the pixel definition layer 112. The ink buffer structure 140 mainly blocks the ink flow to the pixel definition layer 112 to reduce the ink climbing problem caused by the hydrophilicity between the ink and the pixel definition layer 112. Compared with the solution of directly converting the pixel definition layer 112 into a hydrophobic material to prevent ink climbing, the present application improves the shape or structure of the bottom electrode 131, thereby avoiding the need for complex material improvement of the pixel definition layer 112 and avoiding the reduction of the effective light-emitting area of the light-emitting unit 130 caused by the improvement of the pixel definition layer 112. In the present application, the bottom electrode 131 extends towards the pixel definition layer 112 to form the ink buffer structure 140. The ink buffer structure 140 can actually still drive the upper light-emitting functional layer 132 to emit light, so as to ensure the effective light-emitting area of the light-emitting unit 130 while preventing ink climbing.
[0033] Specifically, the light-emitting functional layer 132 generally includes a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, an electron injection layer, etc. arranged in layers in sequence. Of course, the above order can also be inverted. In this embodiment, the hole injection layer is mainly taken as the film layer closest to the bottom electrode 131 for illustration, but it is not limited that the layer closest to the bottom electrode 131 in the light-emitting functional layer 132 is the hole injection layer.
[0034] For the bottom electrode 131, which is generally the anode of the display panel 100, the manufacturing process is completed before the formation of the pixel definition layer 112. When the pixel definition layer 112 forms an opening to define the sub-pixel region 101, the bottom electrode 131 is exposed from the opening, that is, the position of the sub-pixel region 101. Of course, the pixel definition layer 112 generally covers a small amount of the bottom electrode 131. In the direction where the pixel definition layer 112 extends upward from the bottom electrode 131, since there is a certain affinity between the pixel definition layer 112 and the ink, when the ink is at the edge of the pixel definition layer 112, it is easy to climb on the pixel definition layer 112. And when the hole injection layer with the best conductivity in the light-emitting functional layer 132 climbs up higher, it may cause leakage at the position where the film of the edge of the hole injection layer is thinner, affecting the reliability of the OLED display. In this application, by improving the edge part of the bottom electrode 131 and setting up the ink buffer structure 140, the climbing of the ink is prevented.
[0035] Figure 2 is a schematic diagram of the display panel of the first embodiment of this application, Figure 3 is Figure 2 a partial enlarged schematic diagram of, see Figures 2 to 3 As shown, in this embodiment, the ink buffer structure 140 includes a buffer dam 141. The bottom electrode 131 extends upward on the pixel definition layer 112 to form the buffer dam 141. The surface of the buffer dam 141 on the side away from the substrate 110 is higher than the surface of the bottom electrode 131 on the side away from the substrate 110; the buffer dam 141 is used to prevent the ink from climbing onto the pixel definition layer 112 when the light-emitting functional layer 132 is inkjet printed.
[0036] In this embodiment, mainly a buffer dam 141 is formed at the position where the bottom electrode 131 of the pixel definition layer 112 contacts. The buffer dam 141 blocks the ink when the ink levels out towards the edge, reducing the ink flowing towards the pixel definition layer 112, thereby achieving diversion buffering to reduce the climbing height of the ink. Secondly, the buffer dam 141 also increases the distance for the ink to reach the pixel definition layer 112, thereby improving the climbing height of the ink, making the light-emitting functional layer 132 to be printed into a film smoother, and thus improving the optical effect. It can be understood that there is no overlap between the main part of the bottom electrode 131 of this application and the pixel definition layer 112. There is mainly partial overlap between the buffer dam 141 and the pixel definition layer 112.
[0037] Specifically, the formation of the buffer dam 141 includes various methods. For example, through a patterned deposition process, the buffer dam 141 and the bottom electrode 131 with different thicknesses are formed, so that the upper surface of the buffer dam 141 is higher than that of the bottom electrode 131. For example, by depositing the metal material of the bottom electrode 131 multiple times, the buffer dam 141 with a thicker thickness and the bottom electrode 131 with a thinner thickness are formed, so that the upper surface of the buffer dam 141 is higher than the upper surface of the bottom electrode 131. However, since the thickness of the buffer dam 141 is greater than that of the bottom electrode 131, it is easy to cause a difference in the light emission of the light-emitting functional layer 132 in the area where the buffer dam 141 is located and the light-emitting functional layer 132 in the area where the bottom electrode 131 is located.
[0038] In one embodiment, the film layer under the bottom electrode 131 can be adjusted to make the film layer heights of the bottom electrode 131 and the upper surface of the buffer dam 141 different. Specifically, the display panel 100 further includes a pixel driving layer 111 and a planarization layer 120. The pixel driving layer 111 is disposed on the substrate 110, and the planarization layer 120 is disposed on the pixel driving layer 111. The planarization layer 120 is provided with a protrusion 121. The protrusion 121 is disposed between the pixel definition layer 112 and the bottom electrode 131, and in the orthographic projection on the substrate 110, the protrusion 121 overlaps with the buffer dam 141. Among them, the buffer dam 141 and the bottom electrode 131 are processed synchronously, and the protrusion 121 is used to make the surface of the buffer dam 141 on the side away from the substrate 110 (subsequently referred to as the upper surface) higher than the surface of the bottom electrode 131 on the side away from the substrate 110.
[0039] In this embodiment, the main reason for the height difference on the upper surface between the buffer dam 141 and the bottom electrode 131 is achieved by the flat layer 120 provided under the bottom electrode 131. Through the patterning process of the flat layer 120, the upper surface of the film layer corresponding to the area where the buffer dam 141 is located is higher, while the upper surface of the film layer corresponding to the area where the bottom electrode 131 is located is slightly lower, so that a film layer step is formed between the buffer dam 141 and the bottom electrode 131. Thus, when forming the bottom electrode 131 and the buffer dam 141, only one deposition patterning process is required to form the bottom electrode 131 and the buffer dam 141 with the same thickness, and the upper surface heights of the two film layers are different. Without additional processes, only through the deposition patterning process, the buffer dam 141 and the bottom electrode 131 with a film layer step can be formed. Of course, when forming the protrusion 121 of the flat layer 120, the side surface of the protrusion 121 does not need to be perpendicular to the substrate 110. The side surface of the protrusion 121 close to the bottom electrode 131 has a certain inclination angle, so that at the junction between the buffer dam 141 and the bottom electrode 131, instead of forming a film layer step with a large angle, a gradually transitional film layer surface is formed. The gradually transitional buffer dam 141 and bottom electrode 131 have a more uniform film thickness for the light-emitting functional layer 132 or the hole transport layer, making the light emission of the light-emitting functional layer 132 more uniform. Specifically, at the junction between the buffer dam 141 and the bottom electrode 131, there is a transition part, and the transition part has a film layer surface with a certain inclination angle, so as to smoothly connect the upper surface of the buffer dam 141 and the upper surface of the bottom electrode 131, thereby ensuring that the film layer interface between the buffer dam 141 and the bottom electrode 131 is smoother.
[0040] Of course, in different types of display panels 100, there may be other film layers under the bottom electrode 131 and on the pixel driving layer 111. In this embodiment, only the flat layer 120 is used as an example for illustration, and it is not limited that the above scheme of setting the protrusion 121 under the bottom electrode 131 to raise the upper surface height of the buffer dam 141 can only be implemented on the flat layer 120. The advantage of this embodiment is that by improving the film layer under the bottom electrode 131 in the sub-pixel region 101, the driving electrode on the side of the light-emitting unit 130 close to the substrate 110 is formed with a structure of the bottom electrode 131 and the buffer dam 141, where the bottom electrode 131 and the buffer dam 141 are directly connected, and the bottom electrode 131 and the buffer dam 141 together form the driving electrode for driving the light-emitting functional layer 132.
[0041] Specifically, the height difference between the surface of the buffer dam 141 away from the substrate 110 and the surface of the bottom electrode 131 away from the substrate 110 is between 0.5um and 1um.
[0042] In this embodiment, the gap between the upper surface of the buffer dam 141 and the upper surface of the bottom electrode 131 should not be too small or too large. When the gap between the buffer dam 141 and the upper surface of the bottom electrode 131 is small, it cannot prevent the ink from flowing towards the pixel defining layer 112, or the amount of ink blocked from flowing towards the pixel defining layer 112 is small, resulting in a weaker effect of preventing the ink from climbing. When the gap between the upper surface of the buffer dam 141 and the upper surface of the bottom electrode 131 is large, on the one hand, in the case of setting a transition part, when it is necessary to ensure smooth transition, the width of the transition part becomes too wide, squeezing the area of the bottom electrode 131. On the other hand, in the case of not setting a transition part, the larger the film layer step difference between the buffer dam 141 and the bottom electrode 131, the greater the difference in the driving effect on the light-emitting functional layer 132, resulting in a poor overall light-emitting effect of the light-emitting unit 130. Therefore, in this embodiment, by limiting the height difference of the above-mentioned film layer to be between 0.5 um and 1 um, the above phenomenon is better improved, and the light-emitting effect of the light-emitting unit 130 is enhanced.
[0043] In another embodiment, in addition to the method of setting the protrusion 121 on the flat layer 120, the flat layer 120 can also be provided with a groove 122 in the area where the bottom electrode 131 is located. By sinking the bottom electrode 131, a height difference between the upper surfaces of the buffer dam 141 and the bottom electrode 131 is achieved. In other words, the upper surface of the flat layer 120 at the position of the pixel defining layer 112 and the buffer dam 141 is set higher than the upper surface of the position where the bottom electrode 131 is located, so as to achieve the effect of raising the pixel defining layer 112, and further reducing the phenomenon that the ink may cross the pixel defining layer 112.
[0044] Figure 4 It is a schematic diagram of the display panel of the second embodiment of the present application. Figure 5 is Figure 4 a partial enlarged schematic diagram of, see Figures 4 to 5 As shown, the ink buffer structure 140 in this embodiment is a buffer channel 142, which is different from the buffer dam 141 in that a buffer channel 142 is provided near the pixel defining layer 112 for retaining ink to prevent too much ink from climbing along the pixel defining layer 112.
[0045] Specifically, the ink buffer structure 140 includes a buffer channel 142. An extension portion 1311 is provided on the bottom electrode 131 in the extending direction of the pixel defining layer 112. The surface of the extension portion 1311 on the side away from the substrate 110 is lower than the surface of the bottom electrode 131 on the side away from the substrate 110. The buffer channel 142 is formed by the pixel defining layer 112, the extension portion 1311, and the side surface of the bottom electrode 131 higher than the extension portion 1311. The buffer channel 142 is used to prevent the ink from climbing up onto the pixel defining layer 112 during the inkjet printing of the light-emitting functional layer 132.
[0046] The method adopted in this embodiment is different from that in the previous embodiment. Specifically, at the junction position between the bottom electrode 131 and the pixel defining layer 112, a buffer channel 142 is formed by using the bottom electrode 131 and the extension portion 1311 formed by the bottom electrode 131 extending towards the pixel defining layer 112. When the ink flows towards the pixel defining layer 112, the buffer channel 142 stores the ink, reducing the amount of ink climbing up onto the pixel defining layer 112, thereby achieving diversion buffering and reducing the climbing height of the ink. Generally, ink generally includes a solvent and a solute. The solvent generally evaporates during the curing stage, leaving behind the solute. The solute is generally the material of different light-emitting functional layers 132, thereby forming multiple film layers such as a hole injection layer, a hole transport layer, an electron blocking layer, and a light-emitting layer. And mainly there is an affinity between the solvent and the pixel defining layer 112. After the solvent contacts the pixel defining layer 112, it climbs upwards and pushes the solute to a higher position of the pixel defining layer 112. After the solvent volatilizes, the solute closer to the pixel defining layer 112 has a higher height, thus forming the coffee ring effect. In this embodiment, a certain accommodation space is provided at the edge position of the pixel defining layer 112 close to the bottom electrode 131. When the ink flows towards the pixel defining layer 112, due to the greater depth at this position, the ink liquid level is often lower than the ink liquid level at the bottom electrode 131 position. Therefore, the height of the climbing solvent will not exceed the ink liquid level on the bottom electrode 131 by much, thereby improving the coffee ring effect.
[0047] Specifically, there are various ways to form the buffer channel 142, which mainly involves the improvement of the bottom electrode 131, such that the bottom electrode 131 and the extension portion 1311 form the buffer channel 142. It can be like the manufacturing process of the bottom electrode 131 and the buffer dam 141. By multiple depositions combined with a patterning process, the bottom electrode 131 and the extension portion 1311 with different thicknesses are formed, thereby forming the buffer channel 142.
[0048] Of course, in one embodiment, the film layer under the bottom electrode 131 and the extension portion 1311 can also be adjusted to achieve a film layer step difference between the upper surface of the bottom electrode 131 and the upper surface of the extension portion 1311. Specifically, the display panel 100 further includes a pixel driving layer 111 and a planarization layer 120. The pixel driving layer 111 is disposed on the substrate 110, and the planarization layer 120 is disposed on the pixel driving layer 111. The planarization layer 120 is provided with a groove 122. Under the orthographic projection of the substrate 110, the groove 122 overlaps with the extension portion 1311. The bottom electrode 131 and the extension portion 1311 are formed by the same process. The groove 122 is used to make the surface of the extension portion 1311 away from the substrate 110 lower than the surface of the bottom electrode 131 away from the substrate 110.
[0049] In this embodiment, the bottom electrode 131 can be formed in the same process as the extension portion 1311. Through the action of the underlying planarization layer 120, when the bottom electrode 131 and the extension portion 1311 have the same thickness, a film layer step difference appears between the upper surface of the bottom electrode 131 and the upper surface of the extension portion 1311, so as to form a recess, that is, a buffer channel 142, at the position of the extension portion 1311. The bottom surface of the buffer channel 142 is the upper surface of the extension portion 1311. One side of the side surface of the buffer channel 142 is the pixel definition layer 112, and the other side is the transition region between the bottom electrode 131 and the extension portion 1311.
[0050] Specifically, in this embodiment, a transition portion in the previous embodiment can also be added between the extension portion 1311 and the bottom electrode 131. The transition portion is the same as the substrate in the above embodiment and will not be elaborated further in this embodiment.
[0051] Specifically, the width of the buffer channel 142 is between 0.5 μm and 1 μm. Similarly, the width of the buffer channel 142 also affects the degree of ink diversion. When the width of the buffer channel 142 is too wide or too narrow, the ink diversion effect of the buffer channel 142 is not obvious. By limiting the width to be between 0.5 μm and 1 μm, the above phenomenon is better improved, and the light-emitting effect of the light-emitting unit 130 is enhanced.
[0052] Of course, in the above first and second embodiments, the pixel definition layer 112 can be further improved to better adapt to the above ink buffer structure 140. For example, a stepped structure is provided on one side of the pixel definition layer 112 close to the bottom electrode 131 to make it difficult for the ink to climb.
[0053] Figure 6 is a schematic diagram of the display panel according to the third embodiment of the present application, Figure 7 is Figure 6 a partial enlarged schematic diagram of, see Figures 6 to 7As shown, based on the first and second embodiments, the two are combined.
[0054] Specifically, a buffer dam 141 is disposed at the edge of the bottom electrode 131 , an extension portion 1311 is disposed on one side of the buffer dam 141 close to the pixel definition layer 112 , and the bottom electrode 131 , the buffer dam 141 and the extension portion 1311 are electrically connected to form a driving electrode.
[0055] In the present application, the planar layer 120 can also be used to realize the combination of the bottom electrode 131, the buffer dam 141 and the buffer channel 142. The buffer dam 141 blocks the ink when it flows to the edge, so that the ink flowing to the pixel definition layer 112 is reduced, thereby realizing the flow diversion buffer. The buffer channel 142 is also provided on the outside of the buffer dam 141 to further reduce the height of the ink climbing, thereby achieving a better effect.
[0056] It is understandable that the buffer dam 141 or buffer channel 142 or the combination of the buffer dam 141 and buffer channel 142 added in the present application can alleviate the phenomenon of ink climbing to the pixel definition layer 112 to a certain extent. The driving electrode on one side of the light-emitting functional layer 132 may have a slight difference in light emission at the position of the buffer dam 141 and buffer channel 142, but it can be ignored. By setting the buffer dam 141 and buffer channel 142, the effective light-emitting area of the light-emitting functional layer 132 can be greatly increased.
[0057] Figure 8 is a top view schematic diagram of the display panel of the present application, see Figure 8 As shown, the sub-pixel area 101 includes any one of the red sub-pixel area 101R, the green sub-pixel area 101G or the blue sub-pixel area 101B; an ink buffer structure 140 is arranged between two adjacent sub-pixel areas 101 of different colors; and no ink buffer structure 140 is arranged between two adjacent sub-pixel areas 101 of the same color.
[0058] In this embodiment, the buffer dam 141, buffer zone or a combination of the buffer dam 141 and the buffer channel 142 are provided between the sub-pixel regions 101 of different colors. Since the ink of the sub-pixel region 101 of the same color will not cause color mixing even if it goes over the pixel definition layer 112 and enters the adjacent sub-pixel region 101, when the colors of the adjacent sub-pixel regions 101 are the same, it is not necessary to provide the ink buffer structure 140, thereby increasing the aperture ratio of the sub-pixel region 101 at this position.
[0059] Among them, on the bottom electrode 131 of the sub-pixel region 101, a wiring segment 1312 is further provided. The wiring segment 1312 is mainly used to connect the thin-film transistor that drives the light-emitting unit 130. When an ink buffer structure 140 is provided on the side of the wiring segment 1312, the wiring segment extends below the pixel definition layer 112.
[0060] Figure 9 is a schematic diagram of a display panel according to another embodiment of the present application. Refer to Figure 9 As shown, between sub-pixels of different colors, a receiving groove 1121 is further provided on the pixel definition layer 112. The receiving groove 1121 is used to store the ink when the ink flows across the pixel definition layer 112 towards the adjacent sub-pixel region 101 during inkjet printing of the light-emitting functional layer 132.
[0061] In this embodiment, by providing the receiving groove 1121 on the pixel definition layer 112, when the ink may overflow the pixel definition layer 112, the ink is blocked again to prevent the ink from entering the adjacent sub-pixel region 101 and causing contamination. Generally, the proportion of the solvent in the ink that may cross is relatively high and can be removed in the subsequent curing process, while a small amount of the solvent forms in the receiving groove 1121 and does not affect the adjacent sub-pixel region 101. The depth, width, etc. of the receiving groove 1121 can be selected according to the actual situation or test situation.
[0062] Figure 10 is a schematic diagram of a display device of the present application. Refer to Figure 10 As shown, the present application also discloses a display device. The display device 200 includes a driving circuit 210 and any one of the display panels 100 in the above embodiments. Among them, the driving circuit 210 is used to drive the display panel 100 to display.
[0063] It should be noted that the inventive concept of the present application can form a very large number of embodiments. However, due to the limited space of the application documents, it is impossible to list them all. Therefore, on the premise of no conflict, the above-described embodiments or technical features can be combined arbitrarily to form new embodiments. After the combination of each embodiment or technical feature, the original technical effect will be enhanced.
[0064] The above content is a further detailed description of the present application in combination with specific optional implementation manners. It cannot be determined that the specific implementation of the present application is only limited to these descriptions. For those of ordinary skill in the technical field to which the present application belongs, without departing from the concept of the present application, several simple deductions or substitutions can be made, and all should be regarded as belonging to the protection scope of the present application.
Claims
1. A display panel, characterized in that: include: substrate substrate; A plurality of pixel definition layers are formed on the base substrate, and a sub-pixel region is formed between two adjacent pixel definition layers; as well as A plurality of light-emitting units are respectively arranged in a plurality of sub-pixel areas; Wherein, the light-emitting unit comprises a bottom electrode and a light-emitting functional layer, the bottom electrode is arranged on the base substrate, and the light-emitting functional layer is used to be formed on the bottom electrode by inkjet printing; An ink buffer structure is formed on at least one side of the bottom electrode close to the pixel definition layer, and the ink buffer structure is used to prevent ink from climbing onto the pixel definition layer when the light-emitting functional layer is inkjet printed.
2. The display panel according to claim 1, characterized in that: The ink buffer structure comprises a buffer dam, the bottom electrode extends toward the pixel definition layer to form the buffer dam, and the surface of the buffer dam away from the substrate is higher than the surface of the bottom electrode away from the substrate; The buffer dam is used to prevent ink from climbing onto the pixel definition layer when inkjet printing is performed on the light-emitting functional layer.
3. The display panel according to claim 2, characterized in that: The display panel further comprises a pixel driving layer and a planar layer, wherein the pixel driving layer is arranged on the base substrate, and the planar layer is arranged on the pixel driving layer; The flat layer is provided with a protrusion, the protrusion is provided between the pixel definition layer and the bottom electrode, and under the orthographic projection of the base substrate, the protrusion overlaps with the buffer dam; The buffer dam and the bottom electrode are manufactured synchronously, and the protrusion is used to make the surface of the buffer dam away from the substrate higher than the surface of the bottom electrode away from the substrate.
4. The display panel according to claim 3, characterized in that: A height difference between a surface of the buffer dam away from the substrate and a surface of the bottom electrode away from the substrate is between 0.5 um and 1 um.
5. The display panel according to claim 1, characterized in that: The ink buffer structure includes a buffer channel, and the bottom electrode is provided with an extension portion in the direction in which the pixel definition layer is extended, and the surface of the extension portion away from the substrate is lower than the surface of the bottom electrode away from the substrate; the pixel definition layer, the extension portion and the side of the bottom electrode higher than the extension portion form the buffer channel, and the buffer channel is used to prevent ink from climbing up the pixel definition layer when inkjet printing is performed on the light-emitting functional layer.
6. The display panel according to claim 5, characterized in that: The display panel further comprises a pixel driving layer and a planar layer, wherein the pixel driving layer is arranged on the base substrate, and the planar layer is arranged on the pixel driving layer; The flat layer is provided with a groove, and under the orthographic projection of the base substrate, the groove overlaps with the extension portion; The bottom electrode and the extension portion are processed synchronously, and the groove is used to make the surface of the extension portion away from the substrate lower than the surface of the bottom electrode away from the substrate.
7. The display panel according to claim 6, characterized in that: The width of the buffer channel is between 0.5um and 1um.
8. The display panel according to claim 1, characterized in that: The sub-pixel region includes any one of a red sub-pixel region, a green sub-pixel region or a blue sub-pixel region; An ink buffer structure is provided between two adjacent sub-pixel areas of different colors; No ink buffer structure is provided between two adjacent sub-pixel areas of the same color.
9. The display panel according to claim 1, characterized in that: The pixel definition layer is also provided with a receiving groove, and the receiving groove is used to store the ink when the ink flows over the pixel definition layer toward the adjacent sub-pixel area during inkjet printing of the light-emitting functional layer.
10. A display device, characterized in that: It comprises a driving circuit and the display panel according to any one of claims 1 to 9, wherein the driving circuit is used to drive the display panel to display.