Display panel and preparation method thereof

Abstract

The application provides a display panel and a preparation method thereof. The display panel comprises a light-emitting layer, a first refractive layer and a second refractive layer. The first refractive layer is arranged on one side of the light-emitting layer and comprises at least one microlens. The width of the microlens at one end close to the light-emitting layer and at one end away from the light-emitting layer is smaller than the width of the microlens at a middle position. The second refractive layer is arranged on the side of the first refractive layer away from the light-emitting layer and covers the microlens. The anti-interference of the microlens to structural morphology fluctuation is improved by designing the microlens in the first refractive layer as a structure with narrow upper and lower ends and a wide middle part, so that the problems of non-standard technical performance of the microlens and large difference in the effect of the microlens between different panels caused by process fluctuation are solved.

Description

Technical Field

[0001] This invention relates to the field of display technology, and in particular to a display panel and its manufacturing method. Background Technology

[0002] Improving the light extraction efficiency of Organic Light-Emitting Diodes (OLEDs) is beneficial for further reducing overall power consumption and extending screen lifespan. Besides improving efficiency through material upgrades, adjusting the light extraction path of OLEDs to enhance light extraction efficiency is another feasible direction for reducing power consumption. Microlens array (MLA) technology enhances the direct-view light extraction by refracting or reflecting large-angle light to the facing light extraction angle, and is one of the effective means to improve the light extraction efficiency of OLEDs.

[0003] However, due to process limitations, current MLA products inevitably suffer from structural fluctuations and low uniformity, leading to differences in performance between different display panels and consequently a high defect rate in finished products. Summary of the Invention

[0004] The purpose of this invention is to provide a display panel and its manufacturing method to solve the problem of performance differences between different display panels caused by fluctuations and low uniformity of MLA structure in existing display technologies.

[0005] To achieve the above objectives, the present invention provides a display panel comprising a light-emitting layer, a first refractive layer, and a second refractive layer. The first refractive layer is disposed on one side of the light-emitting layer and includes at least one microlens. In a direction perpendicular to the light-emitting layer, the width of the microlens at the end near the light-emitting layer and the end away from the light-emitting layer is smaller than the width at the midpoint of the microlens. The second refractive layer is disposed on the side of the first refractive layer away from the light-emitting layer and covers the microlens.

[0006] Furthermore, the display panel further includes an isolation layer disposed between the microlens and the second refractive layer. Preferably, the refractive index of the isolation layer is greater than that of the first refractive layer and less than that of the second refractive layer. Preferably, the material of the isolation layer includes at least one of organic or inorganic materials.

[0007] Further, the microlens includes a bottom surface and a top surface. The bottom surface is located on the side of the microlens closer to the light-emitting layer. The top surface is parallel to the bottom surface and located on the side of the microlens away from the light-emitting layer. The width of the bottom surface is greater than or equal to the width of the top surface. Preferably, the cross-section of the microlens in the display panel stacking direction is hexagonal.

[0008] Furthermore, the light-emitting layer includes a plurality of light-emitting units, each of which includes at least one light-emitting device. The orthographic projection of the microlens onto the light-emitting layer does not overlap with the orthographic projection of the light-emitting unit onto the light-emitting layer. Preferably, the horizontal distance between the bottom surface and the adjacent light-emitting unit is less than or equal to the horizontal distance between the top surface and the adjacent light-emitting unit.

[0009] Further, the microlens includes a base and a raised portion. The base is disposed on one side of the light-emitting layer. The raised portion is disposed on the side of the base away from the light-emitting layer. The thickness of the base is less than or equal to the thickness of the raised portion. Preferably, the thickness of the base is 30%-50% of the thickness of the microlens. Preferably, the thickness of the raised portion is 50%-70% of the thickness of the microlens. Preferably, the thickness of the microlens is 2-4 micrometers.

[0010] Furthermore, the refractive index of the first refractive layer is less than the refractive index of the second refractive layer. Preferably, the refractive index of the first refractive layer is less than 1.6. Preferably, the refractive index of the second refractive layer is greater than or equal to 1.6.

[0011] Furthermore, the display panel further includes a transition layer disposed between the light-emitting layer and the first refractive layer. Preferably, the material of the transition layer includes at least one of organic and inorganic materials.

[0012] The present invention also provides a method for manufacturing a display panel, comprising the following steps: forming a first refractive layer on one side of a light-emitting layer; forming a microlens in the first refractive layer by a patterning process, wherein the width of the microlens at one end near the light-emitting layer and the other end away from the light-emitting layer is smaller than the width at the middle position of the microlens; and forming a second refractive layer on the side of the first refractive layer away from the light-emitting layer.

[0013] Furthermore, the method for fabricating the display panel further includes: forming an isolation layer on the surface of the microlens. Preferably, the step of forming the isolation layer on the surface of the microlens includes: depositing the material of the isolation layer on the surface of the lens layer using a chemical vapor deposition process, an atomic layer deposition process, or a sol-gel process. Preferably, the material of the isolation layer includes one of organic materials or inorganic materials.

[0014] Furthermore, the patterning process used in forming the microlens in the first refractive layer includes at least one of dry etching, wet etching, or photolithography. Preferably, the photolithography process is digital maskless photolithography.

[0015] Advantages of the present invention: The display panel and its manufacturing method of the present invention improve the anti-interference ability of the microlens to structural morphology fluctuations by setting the microlens in the first refractive layer to a structure with smaller widths at both ends and larger widths in the middle in the display panel stacking direction. This solves the problems of substandard microlens technical performance caused by process fluctuations and large differences in the effect of microlenses between different panels. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the layered structure of the display panel in an embodiment of the present invention;

[0018] Figure 2 This is an enlarged schematic diagram of the cross-sectional structure of the microlens in an embodiment of the present invention;

[0019] Figure 3 This is a schematic flowchart of the display panel manufacturing method in an embodiment of the present invention;

[0020] Figure 4 This is a schematic diagram of the layered structure of the display panel after the transition layer is formed in an embodiment of the present invention;

[0021] Figure 5 This is a schematic diagram of the layered structure of the display panel after the first refractive layer is formed in an embodiment of the present invention;

[0022] Figure 6 This is a schematic diagram of the layered structure of the display panel after the first refractive layer is patterned for the first time in an embodiment of the present invention;

[0023] Figure 7 This is a schematic diagram of the layered structure of the display panel after the first refractive layer is patterned a second time in an embodiment of the present invention;

[0024] Figure 8 This is a schematic diagram of the layered structure of the display panel after the isolation layer is formed in an embodiment of the present invention.

[0025] The components in the diagram are shown below:

[0026] Display panel 1; Light-emitting layer 10;

[0027] Light-emitting unit 11; Transition layer 20;

[0028] First refractive layer 30; Microlens 31;

[0029] Base 311; Elevated section 312;

[0030] Bottom surface 313 of the microlens; Top surface 314 of the microlens;

[0031] Isolation layer 40; Second refractive layer 50. Detailed Implementation

[0032] The following description, with reference to the accompanying drawings, illustrates preferred embodiments of the present invention, demonstrating its implementability. These embodiments provide a complete overview of the invention for those skilled in the art, making its technical content clearer and easier to understand. The present invention can be embodied in many different forms of embodiments, and the scope of protection of the present invention is not limited to the embodiments mentioned herein.

[0033] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. The dimensions and thicknesses of each component shown in the drawings are arbitrary, and the present invention does not limit the dimensions and thicknesses of each component. To make the illustrations clearer, the thickness of components is appropriately exaggerated in some places in the drawings.

[0034] Furthermore, the following descriptions of the embodiments of the invention are made with reference to the accompanying illustrations, illustrating specific embodiments in which the invention can be implemented. Directional terms used in this invention, such as "upper," "lower," "front," "rear," "left," "right," "inner," "outer," and "side," are merely directional references to the accompanying drawings. Therefore, the use of directional terms is for better and clearer explanation and understanding of the invention, and does not indicate or imply that the referred device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] When a component is described as being "on" another component, the component may be placed directly on the other component; alternatively, there may be an intermediate component on which the component is placed, and the intermediate component is placed on the other component. When a component is described as being "installed to" or "connected to" another component, both can be understood as being directly "installed" or "connected" to, or as being indirectly "installed to" or "connected to" another component via an intermediate component.

[0036] In related display technologies, MLA (Micro Lens Array) technology is used to improve the light utilization rate of display panels and enhance the brightness of the display panel when viewed directly. However, the final efficiency improvement of MLA products is highly correlated with their structure. Throughout the display panel, subtle differences in exposure energy, etching solution concentration, and other factors inevitably lead to fluctuations in the structure of the MLA, such as the taper angle. This can easily cause performance instability between different display panels in the same production batch, resulting in a high number of defective products.

[0037] To solve the above-mentioned technical problems, this embodiment of the invention provides a display panel 1, such as... Figure 1 As shown, the display panel 1 includes a light-emitting layer 10, a transition layer 20, a first refractive layer 30, and a second refractive layer 50.

[0038] The light-emitting layer 10 includes multiple light-emitting units 11, and each light-emitting unit 11 includes at least one light-emitting device. This light-emitting device can be one of the following: OLED (Organic Light Emitting Diode), QLED (Quantum Dot Light Emitting Diodes), Mimi-LED (Submillimeter Light Emitting Diode), or Micro-LED (Micro Light Emitting Diode). The light-emitting device converts electrical energy into light energy, thereby providing a light source for the display panel 1, enabling the display panel 1 to display images.

[0039] The transition layer 20 is disposed on the light-emitting surface of the light-emitting layer 10, and its material includes one or more of organic and inorganic materials. Specifically, the transition layer 20 can be an encapsulation functional layer or an insulating functional layer for protecting the light-emitting layer 10, and it can be prepared by TFE (Thin Film Encapsulation) process, deposition process, coating process, and other preparation processes.

[0040] The first refractive layer 30 is disposed on the side of the transition layer 20 away from the light-emitting layer 10, and includes at least one microlens 31. The orthographic projection of the microlens 31 onto the transition layer 20 does not overlap with the orthographic projection of the light-emitting unit 11 onto the transition layer 20. In this embodiment of the invention, the microlens 31 is a single-layer film, which can be formed by creating through holes in the first refractive layer 30 corresponding to the light-emitting unit 11. In other embodiments of the invention, the first refractive layer 30 may include multiple microlenses 31, which may be arranged around the light-emitting unit 11.

[0041] like Figure 2As shown, each microlens 31 has a bottom surface 313 and a top surface 314. The bottom surface 313 is located on the side of the microlens 31 closest to the light-emitting layer 10 and is in contact with the transition layer 20. The top surface 314 is located on the side of the microlens 31 furthest from the light-emitting layer 10 and is parallel to the bottom surface 313. The width of the bottom surface 313 and the width of the top surface 314 of the microlens 31 are smaller than the width at the middle position of the microlens 31. That is, the width of the end of the microlens 31 closest to the light-emitting layer 10 and the end furthest from the light-emitting layer 10 is smaller than the width at its middle position. In this structure, the taper angle of the microlens 31 (i.e., the angle between the bottom surface 313 and the adjacent side surface of the microlens 31) is relatively large, providing excellent resistance to fluctuations in structural morphology. This effectively solves the problems of substandard performance of the microlens 31 caused by process fluctuations and significant differences between different display panels 1 in the same batch. Furthermore, the horizontal distance L1 between the bottom surface 313 of the microlens 31 and the adjacent light-emitting unit 11 is less than or equal to the horizontal distance L2 between its top surface 314 and the adjacent light-emitting unit 11, that is, the width of the bottom surface 313 of the microlens 31 is greater than or equal to the width of its top surface 314, thereby increasing the contact area between the microlens 31 and the transition layer 20, and thus improving the structural stability of the microlens 31. Preferably, the cross-section of the microlens 31 in the stacking direction of the display panel 1 is hexagonal.

[0042] Specifically, such as Figure 2As shown, the microlens 31 includes a base 311 and a raised portion 312. The base 311 is disposed on the surface of the transition layer 20 away from the light-emitting layer 10, and its surface away from the raised portion 312 is the bottom surface 313 of the microlens 31, with a cross-section that is wider at the top and narrower at the bottom in the stacking direction of the display panel 1. The raised portion 312 is disposed on the side of the base 311 away from the light-emitting layer 10, and its surface away from the base 311 is the top surface 314 of the microlens 31, with a cross-section that is narrower at the top and wider at the bottom in the stacking direction of the display panel 1. Preferably, the cross-section of the base 311 is an inverted trapezoid, and the cross-section of the raised portion 312 is a regular trapezoid. Wherein, the thickness h1 of the base 311 is less than or equal to the thickness h2 of the raised portion 312. Compared with the raised portion 312, the larger bottom width and smaller thickness of the base 311 can increase the overall structural stability of the microlens 31 and reduce the patterning difficulty of the first refractive layer 30, while reducing the impact of microlens 31 structural changes on the focusing effect of MLA technology. Preferably, the thickness h1 of the base 311 is 30%-50% of the thickness h of the microlens 31, and the thickness h2 of the raised portion 312 is 50%-70% of the thickness h of the microlens 31; for example, the thickness h1 of the base 311 is 35% or 45% of the thickness h of the microlens 31, and the thickness h2 of the raised portion 312 is 55% or 65% of the thickness h of the microlens 31. Furthermore, the thickness h of the microlens 31 is 2-4 micrometers; for example, the thickness h of the microlens 31 can be 2.5 micrometers or 3 micrometers, the thickness h1 of its base 311 can be 1.25 micrometers or 1.5 micrometers, and the thickness h2 of its raised portion 312 can be 1.25 micrometers or 2.1 micrometers.

[0043] The second refractive layer 50 is disposed on the side of the first refractive layer 30 away from the light-emitting layer 10 and covers the microlens 31. In an embodiment of the invention, the second refractive layer 50 fills the through-holes in the first refractive layer 30 and covers the surface of the microlens 31 facing away from the light-emitting layer 10. In another embodiment of the invention having multiple microlenses 31, the second refractive layer 50 fills the gaps between adjacent microlenses 31 and covers the exposed surface of each microlens 31.

[0044] Both the first refractive layer 30 and the second refractive layer 50 are made of organic or inorganic materials with high light transmittance (greater than 80%). At least a portion of the light emitted by the light-emitting unit 11 passes through the interface between the first refractive layer 30 and the second refractive layer 50. Because the refractive index of the first refractive layer 30 is less than that of the second refractive layer 50, refraction and total internal reflection occur at the interface between the two layers. This reduces the exit angle of the large-angle light emitted by the light-emitting unit 11, adjusting the large-angle light towards a viewing angle parallel to the stacking direction of the display panel 1, thereby achieving a light-focusing effect, reducing light loss, and increasing the viewing brightness of the display panel 1. Further, the refractive index of the first refractive layer 30 is less than 1.6, and the refractive index of the second refractive layer 50 is greater than or equal to 1.6; for example, the refractive index of the first refractive layer 30 is 1.5 or 1.55, and the refractive index of the second refractive layer 50 is 1.7 or 2.0.

[0045] Furthermore, the display panel 1 also includes an insulating layer 40. For example... Figure 1 As shown, an isolation layer 40 is disposed between the microlens 31 and the second refractive layer 50. It can be an organic or inorganic material, such as silicon oxide, oxynitride, or aluminum oxide. Specifically, the isolation layer 40 is made of a material that is immiscible with both the first refractive layer 30 and the second refractive layer 50. For example, when both the first and second refractive layers 30 and 50 are inorganic materials, the isolation layer 40 can be an organic layer; when both the first and second refractive layers 30 and 50 are organic materials, the isolation layer 40 can be an inorganic material. The isolation layer 40 separates the first refractive layer 30 and the second refractive layer 50, preventing them from becoming miscible due to the same or similar materials, thereby protecting the structure of the microlens 31 in the first refractive layer 30. Furthermore, the refractive index of the isolation layer 40 is greater than that of the first refractive layer 30 and less than that of the second refractive layer 50.

[0046] This invention also provides a method for preparing a display panel 1, used to prepare such a panel. Figure 1 The process of manufacturing the display panel 1 shown is as follows: Figure 3 As shown, it includes steps S10-S50.

[0047] Step S10) A transition layer 20 is formed on one side of the light-emitting layer 10:

[0048] One or more organic or inorganic materials are prepared on the light-emitting surface of the light-emitting layer 10 using techniques such as TFE process, deposition process, or coating process to form a light-emitting layer 10. Figure 4 The transition layer 20 shown.

[0049] Step S20) A first refractive layer 30 is formed on one side of the light-emitting layer 10:

[0050] A low-refractive-index material with a refractive index lower than 1.6 is coated onto the transition layer 20, away from the light-emitting layer 10, using a coating or deposition process, to form a layer such as... Figure 5 The first refractive layer 30 shown is illustrated.

[0051] Step S30) Forming microlenses 31 in the first refractive layer 30 using a patterning process:

[0052] The first refractive layer 30 is patterned for the first time using dry etching, wet etching, or photolithography to form a shape such as... Figure 6 The microlens 31 shown has a trapezoidal cross-section. The first refractive layer 30 is then patterned a second time using dry etching, wet etching, or photolithography to reduce the width of the bottom surface 313 of the trapezoidal microlens 31, thereby forming a structure as shown. Figure 7 The cross-section shown is a hexagonal microlens 31.

[0053] In another embodiment of the present invention, a microlens 31 with a hexagonal cross-section can be formed in the first refractive layer 30 by a single photolithography process. Preferably, the photolithography process is digital maskless photolithography.

[0054] Step S40) Forming an isolation layer 40 on the surface of the microlens 31:

[0055] An inorganic or organic material is deposited on the surface of the microlens 31 using a deposition or coating process, and the material covering the transition layer 20 is removed using a patterning process, thereby forming a microlens 31. Figure 8 The isolation layer 40 shown. Preferably, the deposition process used in this step can be one of the following: chemical vapor deposition (CVD), atomic layer deposition (ALD), sol-gel process, etc.

[0056] Step S50) Forming a second refractive layer 50 on the side of the first refractive layer 30 away from the light-emitting layer 10:

[0057] A high refractive index material with a refractive index greater than or equal to 1.6 is applied to the side of the first refractive layer 30 away from the light-emitting layer 10 using inkjet printing, coating, or deposition processes. This high refractive index material then fills the through-holes or gaps in the first refractive layer 30 to form a structure resembling... Figure 1 The second refractive layer 50 is shown in the figure.

[0058] In this embodiment of the invention, the microlenses in the first refractive layer are improved by having a structure with smaller widths at both ends and a larger width in the middle along the stacking direction of the display panel. This enhances the microlens' resistance to structural morphology fluctuations, thereby solving the problems of substandard microlens performance caused by process variations and significant differences in microlens performance between different display panels. This promotes uniform and stable performance across different display panels within the same batch, reducing the defect rate on the production line. Simultaneously, this embodiment of the invention also uses an isolation layer to protect the structure of the microlenses in the first refractive layer, preventing mutual solubility between the first and second refractive layers due to their similar materials.

[0059] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A display panel, characterized in that, include: Emissive layer; A first refractive layer is disposed on one side of the light-emitting layer, and includes at least one microlens. In the direction perpendicular to the light-emitting layer, the width of the microlens at the end closest to the light-emitting layer and the end furthest from the light-emitting layer is smaller than the width at the middle position of the microlens. The second refractive layer is disposed on the side of the first refractive layer away from the light-emitting layer and covers the microlens; An isolation layer is disposed between the microlens and the second refractive layer, and the material of the isolation layer includes a material that is immiscible with both the first refractive layer and the second refractive layer; The microlens includes: The base is located on one side of the light-emitting layer; The raised portion is located on the side of the base away from the light-emitting layer; The thickness of the base portion is less than or equal to the thickness of the raised portion, and the thickness of the base portion is 30%-50% of the thickness of the microlens, while the thickness of the raised portion is 50%-70% of the thickness of the microlens.

2. The display panel as described in claim 1, characterized in that, The refractive index of the isolation layer is greater than that of the first refractive layer and less than that of the second refractive layer.

3. The display panel as described in claim 1, characterized in that, The material of the isolation layer includes at least one of organic or inorganic materials.

4. The display panel as described in claim 1, characterized in that, The microlens includes: One bottom surface is located on the side of the microlens near the light-emitting layer; A top surface, parallel to the bottom surface, and located on the side of the microlens away from the light-emitting layer; The width of the bottom surface is greater than or equal to the width of the top surface.

5. The display panel as described in claim 4, characterized in that, The microlens has a hexagonal cross-section in the direction of the display panel stacking.

6. The display panel as described in claim 4, characterized in that, The light-emitting layer includes a plurality of light-emitting units, and each light-emitting unit includes at least one light-emitting device; The orthographic projection of the microlens onto the light-emitting layer does not overlap with the orthographic projection of the light-emitting unit onto the light-emitting layer.

7. The display panel as described in claim 6, characterized in that, The horizontal distance between the bottom surface and the adjacent light-emitting unit is less than or equal to the horizontal distance between the top surface and the adjacent light-emitting unit.

8. The display panel as described in claim 1, characterized in that, The thickness of the microlens is 2-4 micrometers.

9. The display panel as claimed in claim 1, characterized in that, The refractive index of the first refractive layer is less than that of the second refractive layer.

10. The display panel as claimed in claim 9, characterized in that, The refractive index of the first refractive layer is less than 1.6; The refractive index of the second refractive layer is greater than or equal to 1.

6.

11. The display panel as claimed in claim 1, characterized in that, Also includes: A transition layer is disposed between the light-emitting layer and the first refractive layer.

12. The display panel as claimed in claim 11, characterized in that, The material of the transition layer includes at least one of organic and inorganic materials.

13. A method for manufacturing a display panel, characterized in that, include: A first refractive layer is formed on one side of the light-emitting layer; A microlens is formed in the first refractive layer by a patterning process. The width of the microlens at the end near the light-emitting layer and the end away from the light-emitting layer is smaller than the width at the middle position of the microlens. A second refractive layer is formed on the side of the first refractive layer away from the light-emitting layer; An isolation layer is formed on the surface of the microlens, and the material of the isolation layer includes a material that is immiscible with both the first refractive layer and the second refractive layer. The step of forming a microlens in the first refractive layer by patterning includes: The first refractive layer is patterned to form a raised portion located on one side of the light-emitting layer; The first refractive layer is patterned to form a base located on the side of the raised portion near the light-emitting layer; The thickness of the base portion is less than or equal to the thickness of the raised portion, and the thickness of the base portion is 30%-50% of the thickness of the microlens, while the thickness of the raised portion is 50%-70% of the thickness of the microlens.

14. The method for manufacturing a display panel as described in claim 13, characterized in that, The step of forming the isolation layer on the surface of the microlens includes: depositing the material of the isolation layer on the surface of the microlens by chemical vapor deposition, atomic layer deposition, or sol-gel process.

15. The method for manufacturing a display panel as described in claim 13, characterized in that, The material of the isolation layer includes either organic or inorganic materials.

16. The method for manufacturing a display panel as described in claim 13, characterized in that, The patterning process used in the step of forming the microlens in the first refractive layer includes at least one of dry etching, wet etching, or photolithography. The photolithography process is a digital maskless photolithography process.

Images