Display panel, display device, electronic equipment and manufacturing method

Abstract

The invention discloses a display panel, a display device, electronic equipment and a manufacturing method. The display panel comprises a cathode film layer, the cathode film layer comprises a first area and a second area, and the thickness of the second area is larger than that of the first area; the display panel comprises a sub-pixel area and a non-light-emitting area surrounding the sub-pixel area, the projection of the sub-pixel area on the cathode film layer in the thickness direction is located in the first area, and the projection of the non-light-emitting area on the cathode film layer in the thickness direction covers the second area. The sub-pixel region is arranged below the first region, and the projection of the first region in the thickness direction wraps the projection of the sub-pixel region in the thickness direction, so that more light emitted by the light-emitting layer can penetrate through the first region with smaller thickness, and the light transmittance of the corresponding region is improved. Meanwhile, the thickness of the second region far away from the light-emitting layer in the thickness direction is increased, so that the overall impedance of the cathode film layer is reduced, and the overall uniformity of the display panel is improved.

Description

Technical Field

[0001] The present application relates to the field of intelligent display, and in particular to a display panel, a display device, an electronic device and a manufacturing method. Background Art

[0002] Since current OLED devices mainly use a top emission structure, in which light is emitted from the OLED cathode. In this structure, in order to ensure the luminous efficiency of the OLED, the thickness of the OLED cathode is generally controlled to increase the transmittance of the anode (usually controlled between 40% and 60%) to achieve a better light-transmitting display effect.

[0003] However, after reducing the thickness of the cathode, the impedance of the cathode will increase significantly, causing the OLED display panel to display uneven brightness, affecting the user experience. Summary of the invention

[0004] The embodiments of the present application provide a display panel, a display device, an electronic device and a manufacturing method, which can reduce the impedance of the cathode film layer and improve the display uniformity.

[0005] According to a first aspect of an embodiment of the present application, a display panel is provided, the display panel comprising a cathode film layer, the cathode film layer comprising a first region and a second region, the thickness of the second region being greater than the thickness of the first region;

[0006] The display panel includes a sub-pixel area and a non-luminous area surrounding the sub-pixel area, the orthographic projection of the sub-pixel area on the cathode film layer along the thickness direction is located in the first area, and the orthographic projection of the non-luminous area on the cathode film layer along the thickness direction covers the second area.

[0007] Optionally, the cathode film layer includes a first metal layer and a second metal layer stacked in a thickness direction;

[0008] A hollow area is provided on the second metal layer, the orthographic projection of the hollow area on the cathode film layer along the thickness direction is located in the first area, and the orthographic projection of the hollow area on the cathode film layer along the thickness direction does not intersect with the second area.

[0009] Optionally, the second metal layer and the first metal layer are made of different materials, and the resistivity of the material of the second metal layer is smaller than the resistivity of the material of the first metal layer.

[0010] Optionally, a ratio of the thickness of the second metal layer to that of the first metal layer is greater than or equal to 0.25 and less than or equal to 1.5.

[0011] Optionally, the display panel further includes an anode layer and a light-emitting layer;

[0012] The light emitting layer is disposed between the anode layer and the cathode film layer, and the second metal layer is farther away from the anode layer than the first metal layer.

[0013] Optionally, an edge of the hollow area coincides with an edge of the first zone.

[0014] Optionally, the display panel further includes an anode layer;

[0015] The cathode film layer is an integrated structure, and along the thickness direction, the cathode film layer includes a first surface and a second surface that are arranged opposite to each other; the first surface or the second surface is close to the anode layer, and a groove is provided on the first surface that is concave toward the second surface along the thickness direction;

[0016] The orthographic projection of the groove on the cathode film layer along the thickness direction is located in the first region, and the orthographic projection of the groove on the cathode film layer along the thickness direction does not intersect with the second region.

[0017] Optionally, the ratio of the depth of the groove to the thickness of the cathode film layer in the area away from the groove is greater than or equal to 0.2 and less than or equal to 0.6.

[0018] Optionally, an edge of the groove coincides with an edge of the first region.

[0019] Optionally, the second surface is closer to the anode layer than the first surface.

[0020] Optionally, the display panel further includes an anode layer, a light-emitting layer and a light extraction layer, wherein the light extraction layer is used to improve light extraction efficiency;

[0021] The light emitting layer is arranged between the anode layer and the cathode film layer, and the light extraction layer is arranged at one end of the cathode film layer away from the anode layer.

[0022] Optionally, the display panel includes a pixel defining layer, the pixel defining layer is provided with an opening, and the area corresponding to the opening is the sub-pixel area;

[0023] The orthographic projection of the opening on the cathode film layer is smaller than the first region, and is surrounded by the first region.

[0024] Optionally, a minimum distance from an edge of an orthographic projection of the opening on the cathode film layer to an edge of the first region is less than or equal to 2 micrometers and greater than or equal to 10 micrometers.

[0025] Optionally, the display panel includes a plurality of pixels, each pixel includes a plurality of sub-pixel regions, and the number of the first regions is also plural;

[0026] The orthographic projection of one or more sub-pixel regions on the cathode film layer along the thickness direction is located in one of the first regions.

[0027] According to a second aspect of an embodiment of the present application, a display device is provided, comprising a display panel.

[0028] According to a third aspect of the embodiments of the present application, an electronic device is provided, wherein the display device includes a display panel.

[0029] According to a fourth aspect of the embodiments of the present application, a method for manufacturing a display panel is provided, the manufacturing method comprising:

[0030] forming an anode layer;

[0031] forming a functional film layer on the anode layer;

[0032] forming a cathode film layer at one end of the functional film layer away from the anode layer;

[0033] Among them, the cathode film layer includes a first area and a second area, the thickness of the second area is greater than the thickness of the first area; the orthographic projection of the sub-pixel area on the cathode film layer along the thickness direction is located in the first area, and the orthographic projection of the non-luminous area on the cathode film layer along the thickness direction covers the second area.

[0034] Optionally, the step of forming the cathode film layer includes:

[0035] forming a first metal layer on the functional film layer;

[0036] forming a second metal layer on the first metal layer, wherein a hollow area is provided on the second metal layer;

[0037] The orthographic projection of the hollow area on the cathode film layer along the thickness direction is located in the first area, and the orthographic projection of the hollow area on the cathode film layer along the thickness direction does not intersect with the second area.

[0038] Optionally, the step of forming the cathode film layer includes:

[0039] Depositing a cathode material layer on the functional film layer;

[0040] forming an inwardly recessed groove on a side of the cathode material layer away from the functional film layer to obtain a cathode film layer;

[0041] The orthographic projection of the groove on the cathode film layer along the thickness direction is located in the first region, and the orthographic projection of the groove on the cathode film layer along the thickness direction does not intersect with the second region.

[0042] The technical solution provided by this application may have the following beneficial effects:

[0043] In the above arrangement, the sub-pixel area is arranged below the first area, and the orthographic projection of the first area in the thickness direction wraps the orthographic projection of the sub-pixel area in the thickness direction H, so that the light emitted by the light-emitting layer can pass more through the first area with a thinner thickness, thereby improving the light transmittance of the corresponding area. At the same time, the thickness of the second area away from the light-emitting layer in the thickness direction is increased, thereby reducing the overall impedance of the cathode film layer, thereby improving the overall uniformity of the display panel.

[0044] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of the cross-sectional structure of a display panel in an embodiment of the present application.

[0046] Figure 2 It is a structural diagram of a part of the structure of a display panel in an embodiment of the present application.

[0047] Figure 3 is another schematic cross-sectional structure diagram of a display panel in an embodiment of the present application.

[0048] Figure 4 It is a structural schematic diagram of another part of the structure of the display panel in an embodiment of the present application.

[0049] Figure 5 is another schematic cross-sectional structure diagram of a display panel in an embodiment of the present application.

[0050] Figure 6 It is a schematic diagram of the cross-sectional structure of a display panel in another embodiment of the present application.

[0051] Figure 7 It is a schematic structural diagram of the cathode film layer in another embodiment of the present application.

[0052] Figure 8 It is a schematic structural diagram of the cathode film layer in yet another embodiment of the present application.

[0053] Fig. 9 It is a simplified flow chart of a method for manufacturing a display panel in one embodiment of the present application.

[0054] Fig.10 is another simplified flow chart of a method for manufacturing a display panel in an embodiment of the present application.

[0055] Fig.11 It is a simplified flow chart of a method for manufacturing a display panel in another embodiment of the present application.

[0056] Description of Reference Numerals

[0057] Display panel 10

[0058] Sub-pixel area 11

[0059] Non-luminous area 12

[0060] First sub-pixel 13

[0061] The second sub-pixel 14

[0062] The third sub-pixel 15

[0063] Pixel unit 16

[0064] Opening 17

[0065] Anode layer 100

[0066] Hole injection layer 200

[0067] Hole transport layer 300

[0068] Luminescent layer 400

[0069] Organic light emitting material layer 401

[0070] Electron transport layer 500

[0071] Electron injection layer 600

[0072] Cathode film layer 700

[0073] District 1 701

[0074] District 2 702

[0075] First surface 703

[0076] Second surface 704

[0077] First metal layer 710

[0078] Second metal layer 720

[0079] Hollow area 721

[0080] Groove 730

[0081] Light extraction layer 800

[0082] Buffer layer 900

[0083] Minimum distance d1

[0084] Thickness direction H DETAILED DESCRIPTION

[0085] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The methods described in the following exemplary embodiments do not represent all methods consistent with the present application. Instead, they are merely examples of devices consistent with some aspects of the present application as detailed in the appended claims.

[0086] The terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit this application. Unless otherwise defined, the technical terms or scientific terms used in this application should be understood by people with ordinary skills in the field of this application. The words "first", "second" and similar words used in the specification and claims of this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, similar words such as "one" or "one" do not indicate a quantitative limit, but indicate that there is at least one, and if only "one" is referred to, it will be separately described. "Multiple" or "several" means two or more. Unless otherwise specified, similar words such as "front", "rear", "lower" and / or "upper" are only for the convenience of explanation, and are not limited to one position or one spatial orientation. Similar words such as "include" or "comprise" mean that the elements or objects appearing in front of "include" or "comprise" cover the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. "Connected" or "connected" and similar words are not limited to physical or mechanical connections, and may include electrical connections, whether direct or indirect. The singular forms "a", "said" and "the" used in this specification and the appended claims are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0087] The embodiments of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the features of the following embodiments can be combined with each other.

[0088] like Figure 1As shown, the present application discloses a display panel 10, which can be applied to a display device capable of intelligent display. The display device can be applied to electronic devices (e.g., mobile phones, computers, tablets, etc.). The display panel 10 can be an active light-emitting display panel, such as an organic light emitting diode (OLED) display panel, an active-matrix organic light emitting diode (AMOLED) display panel, a passive-matrix organic light emitting diode (Passive Matrix OLED) display panel, a quantum dot organic light emitting diode (QLED) display panel, etc. It should be noted that the OLED display panel 10 is used as an example for exemplary description in the present application.

[0089] Along the thickness direction, the display panel 10 includes, from bottom to top, an anode layer 100 (Anode), a hole injection layer 200 (Hole Inject Layer, HIL for short), a hole transport layer 300 (Hole Transport Layer, HTL for short), an emitting layer 400 (Emitting Layer; EML), an electron transport layer 500 (Electron Transport Layer, ETL for short), an electron injection layer 600 (Electron Inject Layer, EIL for short) and a cathode film layer 700. It should be noted that the hole injection layer 200, the hole transport layer 300, the emitting layer 400, the electron transport layer 500 and the electron injection layer 600 can be collectively referred to as a functional film layer.

[0090] When the voltages on the anode layer 100 and the cathode film layer 700 are different, a potential difference is formed on the functional film layer between the two, and electrons are injected from the cathode film layer 700 into the electron injection layer 600, and further migrate to the light-emitting layer 400 through the electron transport layer 500. Holes are injected from the anode layer 100 into the hole injection layer 200, and the holes migrate to the light-emitting layer 400 through the hole transport layer 300. At this time, the holes and electrons meet in the light-emitting layer 400, forming excitons and exciting the light-emitting molecules forming the light-emitting layer 400. After the light-emitting molecules are excited, they emit visible light through radiation relaxation.

[0091] Of course, in other embodiments, an electron blocking layer (EBL) and a hole blocking layer (HBL) may also be included, wherein the electron blocking layer is disposed between the hole transport layer 300 and the light emitting layer 400, and the hole blocking layer is disposed between the light emitting layer 400 and the electron transport layer 500.

[0092] It should be noted that the display panel 10 includes a plurality of pixel units 16. In the present embodiment, each pixel unit includes at least three sub-pixels, namely a first sub-pixel 13, a second sub-pixel 14 and a third sub-pixel 15. The first sub-pixel is used to emit red light, the second sub-pixel is used to emit green light, and the third sub-pixel is used to emit blue light. Of course, in other embodiments, the sub-pixels may also emit other light, and the color combination and the number of sub-pixels may be adjusted according to actual conditions.

[0093] like Figure 2 As shown, in this embodiment, the display panel 10 includes a sub-pixel region 11 and a non-luminous region 12 surrounding the sub-pixel region 11. It should be noted that the sub-pixel region 11 is a region having a luminous layer 400, that is, a region that can perform self-luminous display. The sub-pixel region 11 and the non-luminous region 12 together constitute a display area (AA area, refer to Figure 5 and Figure 6 As shown), the non-luminescent area 12 should not be understood as the non-display area (non-AA area) of the display panel 10.

[0094] Combination Figure 3 As shown, the display panel 10 also includes, from bottom to top, a glass substrate layer 21 (Glass), a sacrificial layer 22, an organic layer 23 (PI), a silicon oxide layer 24, a buffer layer 25 (Barrier), a first gate insulating layer 26 (GI1), a dielectric layer 27 (GI2), an interlayer dielectric layer 28 (ILD), a second gate insulating layer 29 (GI3), a planar layer 30 (PLN), a pixel defining layer 31 (PDL) and a support column 32 (PS). In addition, the display panel 10 also includes a bottom shielding metal layer 33 (BSM), a polysilicon layer 34 (poly), a first gate metal layer 35 (GE1), a capacitor top plate electrode layer 36 (GE2), an indium gallium zinc oxide layer 37 (IGZO), a second gate metal layer 38 (GE3), a first source and drain metal layer 39 (SD1), a second source and drain metal layer 40 (SD2) and a third source and drain metal layer 41 (SD3). The connection relationship between each film layer is as shown in FIG. Figure 3 shown.

[0095] Among them, there are multiple organic layers 23 (PI), and a silicon oxide layer 24 for increasing viscosity is arranged between the multiple organic layers 23 (PI). A silicon oxide layer is also arranged between the organic layer 23 (PI) and the buffer layer 25. There are also multiple interlayer dielectric layers 28 (ILD), which are arranged according to actual conditions. It should be noted that the material of the pixel defining layer 31 (PDL) and the support column 32 (PS) is the same, and can be prepared by the same arrangement. Of course, they can also be prepared by different steps. For example, the pixel defining layer 31 (PDL) is obtained first, and then the support column 32 (PS) is obtained.

[0096] like Figure 3 As shown, if necessary, combined Figure 2 and Figure 4 As shown. After the flat layer 30 is prepared, the anode layer 100 is formed on the flat layer 30. Then, a pixel defining layer 31 is formed on the anode layer 100 and the flat layer 30, and then an opening 17 is formed on the pixel defining layer 31 by a patterning process. In other words, it can be understood that the pixel defining layer 31 is provided with an opening 17. Subsequently, an organic light-emitting material layer 401 is formed thereon, and at least part of the organic light-emitting material layer 401 enters the opening 17 to serve as the light-emitting layer 400. In other words, the opening 17 limits the range of the sub-pixel area 11, that is, the area corresponding to the opening 17 is the sub-pixel area 11.

[0097] The following is a brief description of the materials that can be used for each film layer:

[0098] The anode layer 100 may be one or more of a metal material, a conductive metal oxide material, and a conductive carbon material; wherein the metal material includes but is not limited to one or more of Al, Ag, Cu, Mo, Au or alloys thereof; the conductive metal oxide material includes but is not limited to one or more of ITO, IZO, AZO; the conductive carbon material includes but is not limited to one or more of carbon nanotubes, graphene, graphene oxide, etc.

[0099] The material of the hole injection layer 200 can be selected from organic materials with hole transport capability, including but not limited to one or more of polydiphenylamine, polyvinyl carbazole, doped graphene, undoped graphene and C60. The material of the hole transport layer 300 can be selected from inorganic materials with hole transport capability, for example, including but not limited to one or a combination of NiO, NiOx, WOx, MoOx, VOx, and CrOx.

[0100] The material of the electron transport layer 500 can be selected from inorganic materials with electron transport capability, for example, the electron transport material can be a metal oxide or a metal composite oxide. Among them, metal oxides such as ZnO, Al2O3, TiO2, ZrO2, SnO2, Nb2O5, In2O3, etc., metal composite oxides such as ZnMgO, etc. The material of the electron injection layer 600 can be one of metals or metal compounds.

[0101] The material of the cathode film layer 700 is usually an alloy of magnesium (Mg) and silver (Ag). Among them, the component magnesium (Mg) can be used to adjust the work function, that is, to increase the electron injection ability of the cathode film layer 700. The component silver (Ag) is used to improve the conductivity of the cathode film layer 700 and reduce the overall resistance value.

[0102] Since it is necessary to ensure high luminous efficiency, it is necessary to limit the thickness of the cathode film layer 700 to ensure that a sufficient amount of light generated by the light-emitting layer 400 can pass through the cathode film layer 700. However, when the thickness of the cathode film layer 700 is low, the impedance of the cathode film layer 700 will increase significantly. Once the impedance of the cathode film layer 700 increases, the RC loading (resistance and capacitance load) in the display panel 10 will increase, resulting in a significant delay in signal transmission. Therefore, it will cause the display brightness of the display panel 10 to be uneven. The luminous power consumption of the display panel 10 will increase significantly, and the display panel 10 will have a problem of high power consumption.

[0103] In order to solve the above problems, the inventors have conducted the following research:

[0104] Combination Figure 5 and Figure 6 As shown, if necessary, combined Figure 2 and Figure 4 As shown, the cathode film layer 700 includes a first area 701 and a second area 702, and the thickness of the second area 702 is greater than the thickness of the first area 701. The orthographic projection of the sub-pixel area 11 along the thickness direction H on the cathode film layer 700 is located in the first area 701, and the orthographic projection of the non-luminous area 12 along the thickness direction on the cathode film layer 700 covers the second area 702.

[0105] In the above arrangement, the thickness of the first area 701 in the cathode film layer 700 is relatively thin, and the corresponding light transmittance of the first area 701 is relatively high. When light is irradiated on the first area 701, a large portion of the light can penetrate the first area 701 and be emitted outward. The sub-pixel area 11 is arranged below the first area 701, that is, the light-emitting layer 400 is arranged below the first area 701, and the orthographic projection of the first area 701 along the thickness direction wraps the orthographic projection of the sub-pixel area 11 (the area where the light-emitting layer 400 is located) along the thickness direction H, so that the light emitted by the light-emitting layer 400 can pass more through the first area 701 with a relatively thin thickness, thereby improving the light transmittance of the corresponding area. At the same time, the thickness of the second area 702 away from the light-emitting layer 400 along the thickness direction is increased, thereby reducing the overall impedance of the cathode film layer 700, thereby improving the overall display uniformity of the display panel 10 and reducing the power consumption of the display panel 10.

[0106] The orthographic projection of the opening 17 on the cathode film layer 700 is smaller than the first area 701, and is surrounded by the first area 701. In the above arrangement, the light emitted by the light-emitting layer 400 located in the opening 17 can be emitted as much as possible from the first area 701 and outward, avoiding excessive influence on the normally emitted light due to the excessive size of the second area 702 with lower light transmittance. Through the above arrangement, a better display effect of the display panel 10 can be guaranteed.

[0107] In this embodiment, the minimum distance d1 from the edge of the orthographic projection of the opening 17 on the cathode film layer 700 to the edge of the first area 701 is less than or equal to 2 micrometers, and greater than or equal to 10 micrometers. By limiting the minimum value of the minimum distance d1, it is avoided that the second area 702 blocks too much light emitted by the light-emitting layer 400 due to the edge of the opening 17 and the edge of the first area 701 being too close. By limiting the maximum value of the minimum distance d1, it is avoided that the impedance of the cathode film layer 700 is affected due to the space of the second area 702 being too small. At the same time, the second area 702 can also play a role in avoiding the crosstalk problem of the light emitted by the adjacent sub-pixel area 11 to a certain extent.

[0108] The number of the first zone 701 is multiple. Figure 7 As shown, the number of the first regions 701 may be the same as the number of the sub-pixels, and the positive projection of the sub-pixel on the cathode film layer 700 along the thickness direction is located in one of the first regions 701. Figure 4 As shown, the positive projections of the plurality of sub-pixels on the cathode film layer 700 along the thickness direction may also be located in a first area 701. Figure 7 As shown, the shapes of the second area 702 and the light emitting area can be adapted to the shape of the sub-pixel area 11. Figure 4 As shown, the second area 702 can also be bent. Figure 8As shown, the second area 702 may be a regularly arranged mesh structure, and the first area 701 may be a regularly arranged block structure.

[0109] like Figure 5 As shown, in one embodiment, the cathode film layer 700 includes a first metal layer 710 and a second metal layer 720 stacked in the thickness direction. A hollow region 721 is provided on the second metal layer 720, and the orthographic projection of the hollow region 721 on the cathode film layer 700 along the thickness direction H is located in the first area 701, and the orthographic projection of the hollow region 721 on the cathode film layer 700 along the thickness direction H does not intersect with the second area 702. It should be noted that, in this embodiment, the hollow region 721 on the second metal layer 720 is a through hole structure along the thickness direction. Of course, in other embodiments, the hollow region 721 may also be an inwardly concave sink structure.

[0110] By designing the cathode film layer 700 as a two-layer stacked structure and providing a hollow area 721 on one of the layers, the thickness of a part of the cathode film layer 700 is reduced, thereby improving the light transmittance of the area. At the same time, the thickness of another part of the cathode film layer 700 is ensured, thereby reducing the overall impedance value of the cathode film layer 700, thereby improving the uniformity of the overall display of the display panel 10 and reducing the power consumption of the display panel 10.

[0111] In this embodiment, the edge of the hollow area 721 coincides with the edge of the first area 701 .

[0112] In this embodiment, the materials of the second metal layer 720 and the first metal layer 710 are different. The resistivity of the material of the second metal layer 720 is less than the resistivity of the material of the first metal layer 710. Based on the above analysis, it can be seen that the light transmittance and electron injection ability of the second metal layer 720 will not have a significant impact on the light-emitting layer 400. Therefore, in the selection of the material of the second metal layer 720, more attention can be paid to its conductive performance by selecting a material with a lower resistance value. Through the above arrangement, the overall impedance value of the cathode film layer 700 can be further reduced, thereby improving the uniformity of the overall display of the display panel 10 and reducing the power consumption of the display panel 10.

[0113] The material of the second metal layer 720 includes, but is not limited to, gold, silver, copper and a mixture thereof.

[0114] As an optional example, in order to better balance the transmittance, electron injection capability and impedance issues, the inventors conducted a large number of experiments on the ratio (h1 / h2) of the thickness h1 of the second metal layer 720 to the thickness h2 of the first metal layer 710.

[0115] The inventors found that when the ratio of the thickness h1 of the second metal layer 720 to the thickness h2 of the first metal layer 710 is greater than or equal to 0.25, and the ratio is less than or equal to 1.5. When the ratio h1 / h2 is within the above range, since the thickness of the second metal layer 720 is maintained within a suitable range, the overall blocking of the cathode film layer 700 can be greatly reduced, thereby improving the uniformity of the overall display of the display panel 10 and reducing the power consumption of the display panel 10. At the same time, it can be avoided that the thickness of the first metal layer 710 is too high to affect the transmittance, so as to ensure the display effect. In addition, it can also be ensured that the first metal layer 710 with a strong electron injection ability has a sufficient thickness to ensure the display effect.

[0116] In order to better ensure the display effect and ensure that the overall thickness of the cathode film layer 700 is within a reasonable range, the ratio of the thickness h1 of the second metal layer 720 to the thickness h2 of the first metal layer 710 can be controlled within a range of 0.5 to 1. In the display panel 10 designed by the inventor, the thickness of the second metal layer 720 can be controlled within a range of 5 nm to 10 nm, and the thickness of the first metal layer 710 can be controlled within a range of 5 nm to 20 nm.

[0117] As an optional example, the second metal layer 720 is farther away from the anode layer 100 than the first metal layer 710. Since the second metal layer 720 has a hollow area 721, it is disposed on the side of the first metal layer 710 away from the anode layer 100, which can better ensure the flatness of the film layer between the cathode film layer 700 and the anode layer 100, thereby improving the display effect.

[0118] In actual production work, it is necessary to form a hole injection layer 200, a hole transport layer 300, a light-emitting layer 400, an electron transport layer 500, an electron injection layer 600 and a first metal layer 710 on the anode layer 100 by vacuum thermal evaporation in sequence. Afterwards, a second metal layer 720 is formed on the first metal layer 710 in a direction away from the anode layer 100. It should be noted that the first metal layer 710 having a hollow area 721 can be directly formed, or a metal material layer with a flat front surface is first formed, and then a hollow area 721 is formed thereon by etching and other processes, and the first metal layer 710 is obtained. The method of forming the first metal layer 710 includes but is not limited to: vacuum thermal evaporation, electron beam evaporation, imprinting, inkjet printing, etc.

[0119] In the above-mentioned embodiments, the second metal layer 720 and the first metal layer 710 are different film layers formed in different steps. Therefore, the selection of materials can be adjusted according to different design requirements corresponding to different regions. In the selection of the material of the first metal layer 710, more attention should be paid to the ability of electron injection. In the selection of the reinforced material, more attention should be paid to the ability of conductive performance. By using the materials of different film layers and the thickness of different film layers. To adjust the electron injection ability of the cathode film layer 700 located in the sub-pixel area 11 partial structure, and the conductivity of the cathode film layer 700 located in the non-luminous area 12 structure. At the same time, by adjusting the ratio of the thickness of the second metal layer 720 to the first metal layer 710, the transmittance of the cathode film layer 700 located in the sub-pixel area 11 partial structure, and the impedance of the cathode film layer 700 as a whole are balanced.

[0120] Of course, in other embodiments, the second metal layer 720 and the first metal layer 710 may be an integral structure. In other words, the cathode film layer 700 is an integrally formed structure, and the entire structure is made of the same material. As shown below:

[0121] like Figure 6 As shown, the cathode film layer 700 is an integral structure. Along the thickness direction H, the cathode film layer 700 includes a first surface 703 and a second surface 704 arranged opposite to each other. The first surface 703 or the second surface 704 is close to the anode layer 100, and a groove 730 is provided on the first surface 703, which is recessed toward the second surface 704 along the thickness direction H. The orthographic projection of the groove 730 on the cathode film layer 700 along the thickness direction H is located in the first area 701, and the orthographic projection of the groove 730 on the cathode film layer 700 along the thickness direction H does not intersect with the second area 702. The cathode film layer 700 is designed as an integral structure, and the thickness of a part of the cathode film layer 700 only needs to be thinned by etching and other processes to form the groove 730. The thickness of the area (first area 701) where the groove 730 is provided is relatively low, which can improve the light transmittance of the area. The thickness of the area (second area 702) away from the groove 730 is relatively high, which can reduce the overall impedance of the cathode film layer 700.

[0122] In this embodiment, the edge of the groove 730 coincides with the edge of the first area 701. In addition, the second surface 704 is closer to the anode layer 100 than the first surface 703. In other words, the end surface of the cathode film layer 700 away from the anode layer 100 is recessed downward to form a groove. Through the above arrangement, the flatness of the film layer between the cathode film layer 700 and the anode layer 100 can be better guaranteed, thereby improving the display effect.

[0123] As an optional example, in order to better balance the transmittance, electron injection capability and impedance issues, the inventors conducted a large number of experiments on the ratio (h3 / h4) of the depth h3 of the groove 730 and the thickness h4 of the cathode film layer 700 away from the groove 730.

[0124] The inventors found that when the ratio of the depth h3 of the groove 730 and the thickness h4 of the cathode film layer 700 away from the groove 730 is greater than or equal to 0.2, and less than or equal to 0.6, firstly, it can be ensured that the groove 730 has a sufficient depth, so that the first area 701 has a good light transmittance to improve the light extraction efficiency. Secondly, it can be ensured that the thickness of the area where the groove 730 is provided is within a suitable range, and the first area 701 has sufficient electron injection ability to ensure the display effect. In addition, it is ensured that the thickness of the area where the groove 730 is not provided is within a suitable range to effectively reduce the overall blocking of the cathode film layer 700, thereby improving the uniformity of the overall display of the display panel 10 and reducing the power consumption of the display panel 10.

[0125] As an alternative example, combining Figure 5 and Figure 6 As shown, the display panel 10 further includes a light extraction layer 800 (capping layer, referred to as CPL) and a buffer layer 900 (prime). The light extraction layer 800 is used to improve the light extraction efficiency. The light extraction layer 800 is disposed at one end of the cathode film layer 700 away from the anode layer 100. The buffer layer 900 is disposed between the light emitting layer 400 and the hole transport layer 300. In some embodiments, the buffer layer 900 and the electron blocking layer can be selected alternatively.

[0126] In the above configuration, the light extraction layer 800 is disposed at one end of the cathode film layer 700 away from the anode layer 100. Figure 5 In a corresponding embodiment, the light extraction layer 800 is disposed on the second metal layer 720, and a portion of the structure of the light extraction layer 800 enters the hollow region 721. Figure 6 In the corresponding embodiment, the light extraction layer 800 is disposed at one end of the cathode film layer 700 where the groove 730 is opened, and part of the structure of the light extraction layer 800 enters the groove 730. Through the above arrangement, not only the light extraction efficiency can be improved, but also the surface flatness can be further improved.

[0127] like Fig. 9 As shown, the present application also discloses a method for manufacturing a display panel 10, the manufacturing method comprising:

[0128] Step 1000 : forming an anode layer 100 .

[0129] Step 2000: forming functional film layers on the anode layer 100 , that is, sequentially forming a hole injection layer 200 , a hole transport layer 300 , a buffer layer 900 , a light emitting layer 400 , an electron transport layer 500 and an electron injection layer 600 on the anode layer 100 .

[0130] Step 3000 : forming a cathode film layer 700 at one end of the functional film layer away from the anode layer 100 .

[0131] The cathode film layer 700 includes a first region 701 and a second region 702 , the thickness of the second region 702 is greater than the thickness of the first region 701 ; the orthographic projection of the sub-pixel region 11 on the cathode film layer 700 along the thickness direction is located in the first region 701 .

[0132] The display panel 10 obtained through the above steps can ensure that the first area 701 has a high transmittance and the light emitted by the sub-pixel area 11 has a high light extraction efficiency; it can also ensure that the second area 702 has a large thickness to reduce the blocking of the cathode film layer 700 and improve the display effect.

[0133] In different embodiments, the steps of forming the cathode film layer 700 are different.

[0134] Combination Figure 5 and Fig.10 In the embodiment shown, the steps of forming the cathode film layer 700 include:

[0135] Step 3100 ′: forming a first metal layer 710 on the functional film layer.

[0136] Step 3200 ′: forming a second metal layer 720 on the first metal layer 710 , and a hollow region 721 is disposed on the second metal layer 720 .

[0137] The orthographic projection of the hollow area 721 along the thickness direction H on the cathode film layer 700 is located in the first area 701 , and the orthographic projection of the hollow area 721 along the thickness direction H on the cathode film layer 700 does not intersect with the second area 702 .

[0138] In the above configuration, the cathode film layer 700 is divided into two different layers, which facilitates the control of the thickness of the first area 701 and the second area 702. At the same time, the performance of the second area 702 and the first area 701 can be adjusted by controlling the materials of different film layers.

[0139] Combination Figure 6 and Fig.11 In the embodiment shown, the steps of forming the cathode film layer 700 include:

[0140] Step 3100 ”: depositing a cathode material layer on the functional film layer.

[0141] Step 3200 ”: forming an inwardly recessed groove on a side of the cathode material layer away from the functional film layer to obtain a cathode film layer 700 .

[0142] The orthographic projection of the groove 730 on the cathode film layer 700 along the thickness direction H is located in the first region 701 , and the orthographic projection of the groove 730 on the cathode film layer 700 along the thickness direction H does not intersect with the second region 702 .

[0143] In the above arrangement, the cathode film layer 700 is arranged as an integrated structure, which can not only meet the functions but also simplify the process steps.

[0144] The above is only a preferred embodiment of the present application and does not constitute any form of limitation to the present application. Although the present application has been disclosed as a preferred embodiment as above, it is not intended to limit the present application. Any technician familiar with the profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present application. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still falls within the scope of the technical solution of the present application.

Claims

1. A display panel, characterized in that: The display panel includes a cathode film layer, the cathode film layer includes a first area and a second area, and the thickness of the second area is greater than the thickness of the first area; The display panel includes a sub-pixel area and a non-luminous area surrounding the sub-pixel area, the orthographic projection of the sub-pixel area on the cathode film layer along the thickness direction is located in the first area, and the orthographic projection of the non-luminous area on the cathode film layer along the thickness direction covers the second area.

2. The display panel according to claim 1, wherein: The cathode film layer comprises a first metal layer and a second metal layer stacked in a thickness direction; A hollow area is provided on the second metal layer, the orthographic projection of the hollow area on the cathode film layer along the thickness direction is located in the first area, and the orthographic projection of the hollow area on the cathode film layer along the thickness direction does not intersect with the second area.

3. The display panel according to claim 2, wherein: The second metal layer and the first metal layer are made of different materials, and the resistivity of the material of the second metal layer is lower than the resistivity of the material of the first metal layer.

4. The display panel according to claim 2, wherein: A ratio of the thickness of the second metal layer to the thickness of the first metal layer is greater than or equal to 0.25 and less than or equal to 1.

5.

5. The display panel according to claim 2, wherein: The display panel also includes an anode layer and a light-emitting layer; The light emitting layer is disposed between the anode layer and the cathode film layer, and the second metal layer is farther away from the anode layer than the first metal layer.

6. The display panel according to claim 2, wherein: The edge of the hollow area coincides with the edge of the first zone.

7. The display panel according to claim 1, wherein: The display panel also includes an anode layer; The cathode film layer is an integrated structure, and along the thickness direction, the cathode film layer includes a first surface and a second surface that are arranged opposite to each other; the first surface or the second surface is close to the anode layer, and a groove is provided on the first surface that is concave toward the second surface along the thickness direction; The orthographic projection of the groove on the cathode film layer along the thickness direction is located in the first region, and the orthographic projection of the groove on the cathode film layer along the thickness direction does not intersect with the second region.

8. The display panel according to claim 7, wherein: The ratio of the depth of the groove to the thickness of the cathode film layer away from the groove is greater than or equal to 0.2 and less than or equal to 0.

6.

9. The display panel according to claim 7, wherein: The edge of the groove coincides with the edge of the first region.

10. The display panel according to claim 7, wherein: The second surface is closer to the anode layer than the first surface.

11. The display panel according to claim 1, wherein: The display panel further comprises an anode layer, a light emitting layer and a light extraction layer, wherein the light extraction layer is used to improve light extraction efficiency; The light emitting layer is arranged between the anode layer and the cathode film layer, and the light extraction layer is arranged at one end of the cathode film layer away from the anode layer.

12. The display panel according to claim 1, wherein: The display panel comprises a pixel defining layer, the pixel defining layer is provided with an opening, and the area corresponding to the opening is the sub-pixel area; The orthographic projection of the opening on the cathode film layer is smaller than the first region, and is surrounded by the first region.

13. The display panel according to claim 12, wherein: The minimum distance from the edge of the orthographic projection of the opening on the cathode film layer to the edge of the first region is less than or equal to 2 micrometers and greater than or equal to 10 micrometers.

14. The display panel according to claim 1, wherein: The display panel includes a plurality of pixels, each pixel includes a plurality of sub-pixel regions, and the number of the first regions is also a plurality; The orthographic projection of one or more sub-pixel regions on the cathode film layer along the thickness direction is located in one of the first regions.

15. A display device, characterized in that: The display device comprises the display panel according to any one of claims 1 to 14.

16. An electronic device, characterized in that: The display device comprises the display panel according to claim 15.

17. A method for manufacturing a display panel, characterized in that: The production method comprises: forming an anode layer; forming a functional film layer on the anode layer; forming a cathode film layer at one end of the functional film layer away from the anode layer; Wherein, the cathode film layer includes a first area and a second area, the thickness of the second area is greater than the thickness of the first area; the display panel includes a sub-pixel area and a non-luminous area surrounding the sub-pixel area, the orthographic projection of the sub-pixel area on the cathode film layer along the thickness direction is located in the first area, and the orthographic projection of the non-luminous area on the cathode film layer along the thickness direction covers the second area.

18. The method for manufacturing a display panel according to claim 17, wherein: The steps of forming the cathode film layer include: forming a first metal layer on the functional film layer; forming a second metal layer on the first metal layer, wherein a hollow area is provided on the second metal layer; The orthographic projection of the hollow area on the cathode film layer along the thickness direction is located in the first area, and the orthographic projection of the hollow area on the cathode film layer along the thickness direction does not intersect with the second area.

19. The method for manufacturing a display panel according to claim 17, wherein: The steps of forming the cathode film layer include: Depositing a cathode material layer on the functional film layer; forming an inwardly recessed groove on a side of the cathode material layer away from the functional film layer to obtain a cathode film layer; The orthographic projection of the groove on the cathode film layer along the thickness direction is located in the first region, and the orthographic projection of the groove on the cathode film layer along the thickness direction does not intersect with the second region.

Images