Double-sided display panel and manufacturing method

Abstract

The present invention discloses a double-sided display panel and a manufacturing method, wherein the manufacturing method comprises the following steps: manufacturing a thin film transistor on a substrate; manufacturing an insulating layer on the thin film transistor, and manufacturing a through hole connected to the thin film transistor on the insulating layer; manufacturing a first reflective layer on the insulating layer; manufacturing an anode on the insulating layer, and the anode covers the first reflective layer; manufacturing a pixel definition layer on the anode and the insulating layer, and manufacturing a through hole connected to the anode on the pixel definition layer; manufacturing an organic light-emitting layer in the through hole connected to the anode on the pixel definition layer; depositing a cathode material, and forming a cathode covering the organic light-emitting layer on the pixel definition layer and the organic light-emitting layer; and manufacturing a second reflective layer on the cathode in the organic light-emitting layer area. In the above technical solution, the synchronous display of the double-sided display panel and the double-sided asynchronous effect can be realized through a single substrate without sacrificing the picture resolution.

Description

Technical Field

[0001] The present invention relates to the technical field of display panels, and in particular to a double-sided display panel and a manufacturing method thereof. Background Art

[0002] With the popularity of flat panel display devices, it has become possible to make double-sided display devices. Double-sided display is a device that can display images on both sides of the display device. It has a wide range of applications, such as the communications industry, government windows, financial industry, transportation industry, airports, railway stations, subway stations, etc. It can be said that double-sided display has broad development prospects.

[0003] Traditional double-sided display devices are mostly two display panels placed opposite to each other, so that one display panel can be seen on each side. Although this achieves double-sided display, its essence is to stack two single-sided display panels. If two OLEDs are packaged together by mechanical connection, or two packaged single OLEDs are bonded together, it will inevitably bring disadvantages such as large space occupation and high power consumption.

[0004] Double-sided display devices can achieve double-sided display with only one display panel. Compared with traditional double-sided display devices, they have the advantages of thinner panels and lower power consumption, making it possible to use them in small electronic products. Summary of the invention

[0005] Therefore, it is necessary to provide a double-sided display panel and a manufacturing method to solve the problem of excessive thickness of the double-sided display panel.

[0006] To achieve the above object, the inventor provides a method for manufacturing a double-sided display panel, comprising the following steps:

[0007] Fabricating thin film transistors on a substrate;

[0008] An insulating layer covering the thin film transistor is formed on the thin film transistor, and a through hole connected to the thin film transistor is formed on the insulating layer;

[0009] A first reflective layer is formed on the insulating layer, and the first reflective layer is connected to the thin film transistor through a through hole on the insulating layer;

[0010] Depositing an anode material to form a transparent anode on the insulating layer, the anode covers the first reflective layer, and the anode also has a portion on the insulating layer;

[0011] A pixel definition layer is formed on the anode and the insulating layer, and a through hole connected to the anode is formed on the pixel definition layer;

[0012] An organic light emitting layer is fabricated in a through hole connected to the anode on the pixel definition layer;

[0013] Depositing cathode material to form a cathode covering the organic light-emitting layer on the pixel definition layer and the organic light-emitting layer, wherein the cathode is transparent;

[0014] A second reflective layer is formed on the cathode in the organic light emitting layer region, and the second reflective layer is located on one side of the first reflective layer.

[0015] Furthermore, when making a through hole connected to the anode on the pixel definition layer, the following steps are also included:

[0016] Two through holes connected to the anode are made on the pixel definition layer. The two through holes are not connected to each other. The bottom of one through hole is the anode on the first reflective layer, and the bottom of the other through hole is the anode on the insulating layer.

[0017] Furthermore, before depositing the anode material, the following steps are also included:

[0018] A window is made on the insulating layer on one side of the first reflective layer, the anode covers the window of the insulating layer and the first reflective layer, and the second reflective layer is at the window.

[0019] Furthermore, when the second reflective layer is formed on the cathode in the organic light-emitting layer area, the following steps are also included:

[0020] A second reflective layer is made on the cover plate, and then the side of the cover plate having the second reflective layer is covered on the cathode, so that the second reflective layer is connected to the cathode.

[0021] Furthermore, the insulating layer includes a passivation layer and a planarization layer, and the planarization layer is disposed on the passivation layer.

[0022] The inventor provides a double-sided display panel, comprising:

[0023] A thin film transistor is arranged on the substrate;

[0024] An insulating layer covering the thin film transistor is arranged on the thin film transistor, and a through hole connected to the thin film transistor is arranged on the insulating layer;

[0025] A first reflective layer is arranged on the insulating layer, and the first reflective layer is connected to the thin film transistor through a through hole on the insulating layer;

[0026] A transparent anode is arranged on the insulating layer, the anode covers the first reflective layer, and the anode also has a portion on the insulating layer;

[0027] A pixel definition layer is arranged on the anode and the insulating layer, and a through hole connected to the anode is arranged on the pixel definition layer;

[0028] An organic light emitting layer is arranged in a through hole connected to the anode on the pixel definition layer;

[0029] A cathode covering the organic light-emitting layer is arranged on the pixel definition layer and the organic light-emitting layer, and the cathode is transparent;

[0030] A second reflective layer is disposed on the cathode in the organic light emitting layer region, and the second reflective layer is located on one side of the first reflective layer.

[0031] Furthermore, there are two through holes connected to the anode on the pixel definition layer, and the two through holes are not connected to each other. The bottom of one through hole is the anode on the first reflective layer, and the bottom of the other through hole is the anode on the insulating layer.

[0032] Furthermore, a window is arranged on the insulating layer on one side of the first reflective layer, the anode covers the window of the insulating layer and the first reflective layer, and the second reflective layer is at the window.

[0033] Furthermore, a cover plate is included, the second reflective layer is arranged on the cover plate, and the side of the cover plate having the second reflective layer is covered on the cathode, so that the second reflective layer is connected to the cathode.

[0034] Furthermore, the insulating layer includes a passivation layer and a planarization layer, and the planarization layer is disposed on the passivation layer.

[0035] Different from the prior art, in the above technical solution, the first reflective layer and the organic light-emitting layer located on the first reflective layer area form a top light-emitting structure, and the second reflective layer and the organic light-emitting layer located under the second reflective layer area form a bottom light-emitting structure. The synchronous display of the double-sided display panel and the double-sided asynchronous effect can be achieved through a single substrate, which can simplify the manufacturing process of the double-sided display panel and reduce the production cost without sacrificing the picture resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a schematic cross-sectional structure diagram of manufacturing a gate on a substrate in Example 1;

[0037] Figure 2 This is a schematic cross-sectional structure diagram of manufacturing a first insulating layer on a substrate in Example 1;

[0038] Figure 3 This is a schematic cross-sectional structure diagram of manufacturing an active layer on a substrate in Example 1;

[0039] Figure 4 The cross-sectional structure diagram of manufacturing a source electrode and a drain electrode on a substrate in Example 1;

[0040] Figure 5 This is a schematic cross-sectional structure diagram of manufacturing a second insulating layer on a substrate in Example 1;

[0041] Figure 6 This is a schematic cross-sectional structure diagram of manufacturing a third insulating layer on a substrate in Example 1;

[0042] Figure 7 This is a schematic cross-sectional structure diagram of manufacturing a first reflective layer on a substrate in Example 1;

[0043] Figure 8 This is a schematic cross-sectional structure diagram of manufacturing an anode on a substrate in Example 1;

[0044] Fig. 9 This is a schematic cross-sectional structure diagram of manufacturing a pixel definition layer on a substrate in Example 1;

[0045] Fig.10 This is a schematic cross-sectional structure diagram of manufacturing an organic light-emitting layer on a substrate in Example 1;

[0046] Fig.11 This is a schematic cross-sectional structure diagram of manufacturing a cathode on a substrate in Example 1;

[0047] Fig.12 This is a schematic cross-sectional structure diagram of manufacturing a second reflective layer on a substrate in Example 1;

[0048] Fig.13 This is a schematic diagram of the structure of the top-lighting and bottom-lighting double-sided display panel according to the first embodiment; Fig.14 A schematic cross-sectional structure diagram of another embodiment in which the thickness of the second insulating layer is increased on the substrate; Fig.15 This is a schematic cross-sectional structure diagram of manufacturing two organic light-emitting layers on a substrate in Example 2;

[0049] Fig.16 This is a schematic cross-sectional structure diagram of manufacturing a window on a substrate in Example 3;

[0050] Fig.17 This is a schematic cross-sectional structure diagram of a fourth embodiment in which a second reflective layer is provided on the cover plate.

[0051] Description of reference numerals:

[0052] 1. Substrate;

[0053] 2. Gate material;

[0054] 21. A first gate;

[0055] 22. Second grid;

[0056] 3. The first insulating layer;

[0057] 4. Active layer materials;

[0058] 41. A first active layer;

[0059] 42. a second active layer;

[0060] 5. Source and drain materials;

[0061] 51. First source;

[0062] 52. a first drain;

[0063] 53. Second source;

[0064] 54. a second drain;

[0065] 6. Second insulation layer;

[0066] 7. The first reflective layer;

[0067] 8. Anode;

[0068] 9. Pixel definition layer;

[0069] 10. Organic light-emitting layer;

[0070] 11. Cathode;

[0071] 12. The second reflective layer;

[0072] 13. The third insulating layer;

[0073] 14. Cover plate. DETAILED DESCRIPTION

[0074] In order to explain the technical content, structural features, achieved objectives and effects of the technical solution in detail, the following is a detailed description in conjunction with specific embodiments and accompanying drawings.

[0075] See also Figures 1 to 17 , this embodiment provides a method for manufacturing a double-sided display panel, which can be manufactured on a substrate, and the substrate can be glass, transparent plastic, metal foil, etc. commonly used in existing process technology. The manufacturing method includes the following steps: first, a thin film transistor (TFT) is manufactured on the substrate, and the TFT can be a top gate structure, a bottom gate structure, a BCE structure, an ESL structure (with an etching barrier layer on the active layer) or other structures. Here, the manufacturing of two BCE structure TFTs is used as an example for explanation; specifically, a photoresist can be coated on the substrate 1, and the photoresist is patterned, that is, the photoresist is exposed and developed, so that the first gate of the TFT to be manufactured and the area of ​​the second gate to be manufactured are opened. Then, the gate material 2 is plated, which can be one or more metals with good conductivity such as aluminum, molybdenum, titanium, nickel, copper, silver, chromium, etc., and alloys. Then, a first gate 21 is formed in the area where the first gate is to be manufactured, and a second gate 22 is formed in the area where the second gate is to be manufactured, and finally the photoresist is removed. The first gate 21 serves as the gate of one TFT, and the second gate 22 serves as the gate of another TFT.

[0076] It should be noted that if one TFT is to be manufactured, only one gate electrode is required, and if multiple TFTs are to be manufactured, multiple gate electrodes of the TFTs are required. The same is true for the source electrodes and drain electrodes of multiple TFTs, which will not be described in detail below.

[0077] See also Figure 2 In the first embodiment, after the gate is manufactured, a first insulating layer with an insulating function is manufactured on the gate: specifically, an insulating material such as nitride (silicon nitride, etc.), oxide (silicon oxide, silicon dioxide) or other insulating materials can be plated on the substrate 1 to form a first insulating layer 3 on the substrate 1. The first insulating layer 3 with an insulating function covers the first gate 21 and the second gate 22, and can prevent the first gate 21 and the second gate 22 from contacting with other metal electrodes.

[0078] See also Figure 2 In the first embodiment, in order to form a connection between two TFTs, a through hole connected to the gate can be made on the first insulating layer above the gate of one TFT, and then the source or drain of another TFT can be connected to the gate of one TFT through the through hole connected to the gate on the first insulating layer, so that the connection between the two TFTs can be formed.

[0079] See also Figure 3 In the first embodiment, after the first insulating layer is made, an active layer is made on the first insulating layer above each gate. Specifically, a photoresist can be coated on the substrate 1, and the photoresist is patterned, that is, the photoresist is exposed and developed to open the area where the first active layer and the second active layer are to be made. Then, an active layer material 4 is plated, and the active layer material 4 can be polysilicon, oxide semiconductor, graphene, carbon nanotube, organic semiconductor, etc., and a first active layer 41 is formed on the first insulating layer 3 above the first gate 21, and a second active layer 42 is formed on the first insulating layer 3 above the second gate 21. After the first active layer 41 and the second active layer 42 are made, the photoresist is removed.

[0080] See also Figure 4In the first embodiment, after the active layer is made, the first source and the first drain of one TFT and the second source and the second drain of another TFT are made at the same time; specifically, a photoresist can be coated on the substrate 1, and the photoresist can be patterned, that is, the photoresist is exposed and developed, so that the regions where the first source, the first drain, the second source and the second drain are to be made are opened. Then the source and drain material 5 is deposited, and the source and drain material 5 can be one or more metals with good conductivity such as aluminum, molybdenum, titanium, nickel, copper, silver, chromium, etc., and alloys. After the source and drain material 5 is deposited, a first source 51 is formed on one side of the first active layer 41, a first drain 52 is formed on the other side of the first active layer 41, a second source 53 is formed on one side of the second active layer 42, and a second drain 54 is formed on the other side of the second active layer 43. The first gate 21, the first source 51 and the first drain 52 form a TFT, and the second gate 22, the second source 53 and the second drain 54 form another TFT. Among them, the second source 53 can be connected to the first gate 21 through a through hole on the first insulating layer 3 connected to the first gate 21, or the second drain 54 can be connected to the first gate 21 through a through hole on the first insulating layer 3 connected to the first gate 21, so that the connection between the two TFTs can be realized.

[0081] See also Figure 5 In the first embodiment, after the source and drain electrodes are manufactured, a second insulating layer with an insulating function is manufactured on the source, drain and active layer; specifically, an insulating material such as nitride (silicon nitride, etc.), oxide (silicon oxide, silicon dioxide) or other insulating materials can be plated on the substrate 1 to form a second insulating layer 6 on the source, drain and active layer. The second insulating layer 6 covers the first source electrode, the second source electrode, the first drain electrode, the second drain electrode, the first active layer and the second active layer and protects them, so that the first source electrode, the second source electrode, the first drain electrode, the second drain electrode, the first active layer and the second active layer are not interfered by other film layers.

[0082] See also Figure 6 In the first embodiment, a third insulating layer is formed on the second insulating layer. The third insulating layer 13 can fill the uneven substrate and is also called a flat layer. The material of the third insulating layer 13 can be the same as that of the second insulating layer, such as nitride (silicon nitride, etc.), oxide (silicon oxide, silicon dioxide), polyimide or other insulating materials. Then, a first reflective layer and a pixel definition layer can be formed on the third insulating layer 13.

[0083] Alternatively, when making the second insulating layer, by increasing the thickness of the second insulating layer, it can act as a third insulating layer to flatten the uneven multiple film layers on the substrate. In this way, there is no need to make a third insulating layer, which can save a photomask and a film layer, and save production costs. Then, the first reflective layer and the pixel definition layer and other film layers can be made on the second insulating layer.

[0084] See also Figure 6 In the first embodiment, after the source and drain electrodes are made, a through hole connected to the drain electrode is made on the third insulating layer, and the through hole connected to the drain electrode on the third insulating layer is used as a connection point with the first reflective layer; specifically, a photoresist may be coated on the substrate, and then the photoresist is exposed and developed to open the portion where the through hole is to be made. Then, the third insulating layer is etched to the first drain electrode using the photoresist as a mask, and a through hole connected to the first drain electrode is formed on the third insulating layer. The through hole allows the drain electrode to be connected to the first reflective layer, thereby further allowing a connection to be formed between the subsequently made organic light-emitting layer and the TFT. Of course, if the thickness of the second insulating layer is increased, a through hole connected to the drain electrode can be made on the second insulating layer.

[0085] See also Figure 7 In the first embodiment, a first reflective layer is then formed on the third insulating layer. The first reflective layer can better reflect the light emitted by the organic light-emitting layer to the direction of the cover plate to form top emission. Specifically, a photoresist can be coated on the substrate and patterned, that is, the photoresist is exposed and developed so that the area where the first reflective layer is to be formed is opened. Then the first reflective layer material is plated to form a first reflective layer 7 on the third insulating layer 13. The first reflective layer 7 is located in the through hole of the third insulating layer 13 and on the surface of the third insulating layer 13. The first reflective layer 7 is connected to the first drain electrode 52 through the through hole on the third insulating layer 13, thereby forming a connection between the anode covered on the first reflective layer 7 and the TFT. After the first reflective layer 7 is made, the photoresist is removed. The first reflective layer material can be one or more metals with good conductivity such as aluminum, molybdenum, titanium, nickel, copper, silver, chromium, and alloys. These metals have high reflectivity and can reflect light, reflecting the light emitted from the organic light-emitting layer to the direction of the cover plate to form top emission. Of course, the first reflective layer does not need to be made, because the organic light-emitting layer can originally send light to the cover plate.

[0086] See also Figure 8In the first embodiment, an anode is then made on the third insulating layer: specifically, a photoresist may be coated on the substrate, and the photoresist may be patterned, that is, exposed and developed to open the area where the anode is to be made. Then, an anode material is deposited to form a transparent anode 8 on the third insulating layer, and the anode 8 covers the first reflective layer 7 on the third insulating layer 13, and finally the photoresist is removed. The anode material may be an indium tin oxide (ITO) thin film material and carbon nanotubes, etc., which may allow the transparent anode 8 to be penetrated by light from the organic light-emitting layer. Preferably, the anode has a portion that exceeds the TFT in the vertical direction, and the portion of the anode that exceeds the TFT is used to form a bottom light-emitting structure with the organic light-emitting layer on this portion.

[0087] See also Fig. 9 , Fig.10 and Fig.13 In the first embodiment, after the anode is manufactured, a pixel definition layer 9 is manufactured on the third insulating layer 13 and the anode 8. Then, a through hole connected to the anode 8 is manufactured on the pixel definition layer 9. The through hole connected to the anode 8 on the pixel definition layer 9 is used as a connection point between the anode 8 and the organic light-emitting layer 10. Then, an organic light-emitting layer 10 of RGB pixels is manufactured in the through hole connected to the anode 8 in the pixel definition layer 9. The organic light-emitting layer 10 includes a hole injection layer HIL, a hole transport layer HTL, an organic light-emitting layer EM, an electron transport layer ETL, and an electron injection layer EIL. The first reflective layer 7 and the organic light-emitting layer 10 located on the first reflective layer region form a top emission structure. The top emission structure can realize the top emission function of a double-sided display panel, such as Fig.14 shown.

[0088] See also Fig.11 In the first embodiment, a cathode is then made on the pixel definition layer and the organic light emitting layer; specifically, a photoresist can be coated on the substrate, and the photoresist is patterned, that is, the area where the cathode is to be made is opened by exposure and development. Then, the cathode material is evaporated to form a cathode 11 covering the organic light emitting layer on the pixel definition layer 9 and the organic light emitting layer 10, and finally the photoresist is removed. The cathode material can be a material with similar properties such as magnesium-silver alloy to form a transparent cathode 11, which allows the light emitted by the organic light emitting layer 10 and the light reflected by the second reflective layer 12 to pass through.

[0089] See also Fig.12 and Fig.13In the first embodiment, after the cathode is manufactured, a second reflective layer is manufactured on the cathode, and the second reflective layer can reflect light to form bottom luminescence; specifically, a photoresist can be coated on the substrate, and the photoresist can be patterned, that is, the photoresist is exposed and developed to open the area where the second reflective layer is to be manufactured. Then the second reflective layer material is plated to form a second reflective layer 12 on the cathode 11. The second reflective layer 12 is located on the cathode in the area of ​​the organic light-emitting layer 10, and finally the photoresist is removed. The second reflective layer material can be one or more metals with excellent conductivity, such as aluminum, molybdenum, titanium, nickel, copper, silver, chromium, and alloys. These metals have high reflectivity, so that the second reflective layer 12 can reflect light, and reflect the light from the organic light-emitting layer 10 to the direction of the substrate, forming bottom luminescence, such as Fig.14 As shown. The second reflective layer 12 and the organic light-emitting layer 10 located under the second reflective layer region form a bottom light-emitting structure. The bottom light-emitting structure can realize the bottom light-emitting function of the double-sided display panel. Preferably, the second reflective layer 12 is located on one side (outside) of the first reflective layer 7, so that the light reflected by the second reflective layer 12 and the first reflective layer 7 does not interfere with each other.

[0090] In the first embodiment, a cover plate 14 may be finally placed on the second reflective layer 12 and the cathode 11 and a packaging process may be performed.

[0091] In order to allow the reflective layer (the first reflective layer and the second reflective layer) to better reflect the light of the organic light-emitting layer, in Example 2 and Example 3, corresponding improvements are made on the basis of Example 1. In Example 2 and Example 3, only different processes are described, and the various processes behind the different processes are still the same as in Example 1, so they will not be repeated.

[0092] See also Fig.15 In the second embodiment, in order to reduce the mutual interference between the two light emission modes of top emission and bottom emission, two organic light emitting layers are made, and there is a gap between the two organic light emitting layers; specifically, two through holes connected to the anode 10 can be made on the pixel definition layer 9, the bottom of one through hole connected to the anode 10 is the anode 10 on the first reflective layer 7, and the bottom of the other through hole connected to the anode 10 is the anode 10 on the third insulating layer 13. Then, the first organic light emitting layer 10 is made in the through hole on the pixel definition layer 9 whose bottom is the anode on the first reflective layer, and the second organic light emitting layer 10 is made in the through hole on the pixel definition layer 9 whose bottom is the anode on the third insulating layer. Then, the second reflective layer 12 can be made on the area of ​​the second organic light emitting layer 10. In this way, the interference of reflected light can be better avoided between the second reflective layer 12 and the first reflective layer 7, which is conducive to improving the display effect.

[0093] See also Fig.16In the third embodiment, in order to reduce the thickness of the bottom emitting light penetrating the film layer, a window can be made on the third insulating layer where the pixel definition layer is located in the second reflective layer area, and the bottom of the window can be the second insulating layer or the first insulating layer. The cross-sectional shape of the window can be circular, square, or fan-shaped. After that, the anode material, cathode material, and second reflective layer material can be plated in sequence, so that the bottom emitting structure is arranged in the window, closer to the substrate. In this way, the thickness of the film layer through which the light reflected by the bottom emitting structure penetrates can be reduced, and the luminous efficiency can be further improved.

[0094] See also Fig.17 Alternatively, in the fourth embodiment, the second reflective layer 12 may be disposed on the cover plate 14, the second reflective layer 12 being above the anode on the third insulating layer and located on the side of the cover plate close to the substrate. The side of the cover plate with the second reflective layer is covered on the cathode, so that the second reflective layer is connected to the cathode. The same effect of reflecting light can be achieved, and at the same time, since the second reflective layer 12 is disposed on the cover plate 14, the number of process steps after the evaporation of the organic light-emitting layer is reduced, and the damage to the light-emitting layer by the process is further reduced, so as to improve the yield of the display panel.

[0095] The double-sided display panel of the above technical solution has two light-emitting structures in each RGB sub-pixel, namely, top-emitting and bottom-emitting structures. The top-emitting OLED device and the bottom-emitting OLED device are controlled by thin film transistors. The synchronous display of the double-sided display panel and the double-sided asynchronous effect can be achieved through a single array substrate, which can simplify the manufacturing process of the double-sided display panel, reduce the production cost, and do not sacrifice the picture resolution.

[0096] This embodiment provides a double-sided display panel, which is manufactured by the above manufacturing method. Figures 1 to 17 The double-sided display panel includes: a substrate 1 which can be glass, transparent plastic, metal foil, etc. commonly used in existing manufacturing processes. Figure 1 , a TFT gate is arranged on the substrate, wherein the TFT may be a top gate structure, a bottom gate structure, a BCE structure, an ESL structure (with an etching stopper layer on the active layer) or other structures. The gate may be one or more of the metals with good conductivity such as aluminum, molybdenum, titanium, nickel, copper, silver, chromium, and alloys. Please refer to Figure 2 A first insulating layer covering the gate is arranged on the gate. The first insulating layer may be made of nitride (silicon nitride, etc.), oxide (silicon oxide, silicon dioxide) or other insulating materials. The first insulating layer with insulating function covers the gate to prevent the gate from contacting other metal electrodes.

[0097] See also Figure 3In the first embodiment, an active layer of the TFT is disposed on the first insulating layer in the gate region. The active layer material may be polysilicon, oxide semiconductor, graphene, carbon nanotube, organic semiconductor, etc.

[0098] See also Figure 4 In the first embodiment, a source electrode is arranged on one side of the active layer, and a drain electrode is arranged on the other side of the active layer, and the gate electrode, the source electrode and the drain electrode constitute a TFT. Among them, the source and the drain electrode can be one or more metals with good conductivity such as aluminum, molybdenum, titanium, nickel, copper, silver, chromium, and alloys. One TFT can be arranged on the substrate, and multiple TFTs can also be arranged. The drawings in the present application show that two TFTs are arranged on the substrate, one TFT includes a first gate electrode, a first source electrode and a first drain electrode, and the other TFT includes a second gate electrode, a second source electrode and a second drain electrode.

[0099] See also Figure 4 In the first embodiment, if multiple TFTs are to be connected, a through hole connected to the gate is provided on the first insulating layer in the gate region of one TFT, and then the source or drain of another TFT is connected to the gate of one TFT through the hole in the first insulating layer above the gate of one TFT. For example, a through hole connected to the first gate is provided on the first insulating layer in the first gate region, and the second source or the second drain is connected to the first gate through the hole in the first insulating layer above the first gate, so that the two TFTs are connected.

[0100] See also Figure 5 In the first embodiment, a second insulating layer covering the source electrode, the drain electrode and the active layer is provided on the source electrode, the drain electrode and the active layer. The second insulating layer is made of nitride (silicon nitride, etc.), oxide (silicon oxide, silicon dioxide) or other insulating materials. A through hole connected to the drain electrode (first drain electrode) is provided on the second insulating layer as a connection point between the first reflective layer and the drain electrode.

[0101] See also Figure 6 In the first embodiment, a third insulating layer is formed on the second insulating layer. The third insulating layer 13 can make the substrate uneven due to multiple processes. The third insulating layer 13 is also called a flat layer. The material of the third insulating layer 13 can be the same as that of the second insulating layer, such as nitride (silicon nitride, etc.), oxide (silicon oxide, silicon dioxide), polyimide or other insulating materials.

[0102] See also Fig.14 In some embodiments, by increasing the thickness of the second insulating layer, it can act as a third insulating layer to flatten the uneven layers on the substrate. This eliminates the need to provide a third insulating layer, saving costs.

[0103] See also Figure 7In the first embodiment, a first reflective layer is provided on the third insulating layer, and the first reflective layer is connected to the first drain electrode through a through hole on the third insulating layer connected to the first drain electrode. The material of the first reflective layer can be one or more metals with good conductivity such as aluminum, molybdenum, titanium, nickel, copper, silver, chromium, and alloys. These metals have high reflectivity and can reflect light, reflecting the light from the organic light-emitting layer to the direction of the cover plate to form top emission.

[0104] See also Figure 8 In the first embodiment, a transparent anode is arranged on the second insulating layer, and the anode also covers the first reflective layer. The anode material can be an indium tin oxide (ITO) thin film material and a carbon nanotube, etc., so that the transparent anode can be penetrated by the light of the organic light-emitting layer. Preferably, the anode has a portion that exceeds the TFT in the vertical direction, and the portion of the anode that exceeds the TFT is used to form a bottom light-emitting structure with the organic light-emitting layer on this portion.

[0105] See also Fig. 9 In the first embodiment, a pixel definition layer is disposed on the anode and the second insulating layer. A through hole connected to the anode is disposed on the pixel definition layer, and the through hole is used as a connection point between the anode and the organic light emitting layer.

[0106] See also Fig.10 In the first embodiment, an organic light-emitting layer of RGB is arranged in the through hole connected to the anode on the pixel definition layer, and the organic light-emitting layer includes a hole injection layer HIL, a hole transport layer HTL, an organic light-emitting layer EM, an electron transport layer ETL, and an electron injection layer EIL. The first reflective layer and the organic light-emitting layer located on the first reflective layer region form a top-emitting structure, and the top-emitting structure can realize the top-emitting function of the double-sided display panel.

[0107] See also Fig.11 In the first embodiment, a cathode covering the organic light emitting layer is disposed on the pixel definition layer and the organic light emitting layer. The cathode can be made of a material having similar properties such as magnesium-silver alloy, so that the cathode can be transparent, and the transparent cathode can allow the light emitted by the organic light emitting layer and the light reflected by the second reflective layer to pass through.

[0108] See also Fig.12In the first embodiment, a second reflective layer is provided on the cathode in the organic light-emitting layer region. The second reflective layer material may be one or more metals with excellent conductivity such as aluminum, molybdenum, titanium, nickel, copper, silver, chromium, and alloys. These metals have high reflectivity, so that the second reflective layer can reflect light, and reflect the light from the organic light-emitting layer to the direction of the substrate to form bottom light emission. The second reflective layer and the organic light-emitting layer located under the second reflective layer region form a bottom light-emitting structure. The bottom light-emitting structure can realize the bottom light-emitting function of the double-sided display panel. Preferably, the second reflective layer is located on one side (outside) of the first reflective layer, so that the light reflected by the second reflective layer and the first reflective layer 7 does not interfere with each other.

[0109] In the first embodiment, a cover plate may be placed on the second reflective layer and the cathode, and a packaging process may be performed.

[0110] In order to allow the reflective layer (the first reflective layer and the second reflective layer) to better reflect the light of the organic light-emitting layer, in Example 2 and Example 3, corresponding improvements are made on the basis of Example 1. In Example 2 and Example 3, only different processes are described, and the various processes behind the different processes are still the same as in Example 1, so they will not be repeated.

[0111] See also Fig.15 In the second embodiment, in order to reduce the mutual interference between the two light-emitting modes of top emission and bottom emission, two organic light-emitting layers are provided, and there is a gap between the two organic light-emitting layers; specifically, two through holes connected to the anode 10 may be provided on the pixel definition layer 9, the bottom of one through hole connected to the anode 10 is the anode 10 on the first reflective layer 7, and the bottom of the other through hole connected to the anode 10 is the anode 10 on the third insulating layer 13. Then, the first organic light-emitting layer 10 is provided in the through hole on the pixel definition layer 9 whose bottom is the anode on the first reflective layer, and the second organic light-emitting layer 10 is provided in the through hole on the pixel definition layer 9 whose bottom is the anode on the third insulating layer. Then, the second reflective layer 12 may be provided on the region of the second organic light-emitting layer 10. In this way, the interference of reflected light can be better avoided between the second reflective layer 12 and the first reflective layer 7, which is conducive to improving the display effect.

[0112] See also Fig.16 In the third embodiment, in order to reduce the thickness of the bottom emitting light penetrating the film layer, a window is provided on the third insulating layer (the third insulating layer on the side of the first reflecting layer) in the area where the pixel definition layer is located in the second reflecting layer, and the bottom of the window can be the third insulating layer, the first insulating layer or the second insulating layer. Then, an anode, a cathode and a second reflecting layer can be provided in and outside the window, so that the bottom emitting structure is provided in the window, closer to the substrate. In this way, the thickness of the film layer through which the light reflected by the bottom emitting structure penetrates can be reduced, and the luminous efficiency can be further improved.

[0113] See also Fig.17 In the fourth embodiment, the second reflective layer 12 can also be arranged on the cover plate 14. The second reflective layer 12 is above the anode on the third insulating layer and is located on the side of the cover plate close to the substrate. The side of the cover plate with the second reflective layer is covered on the cathode so that the second reflective layer is connected to the cathode. The same effect of reflecting light can be achieved. At the same time, since the second reflective layer 12 is arranged on the cover plate 14, the number of process steps after the organic light-emitting layer is evaporated is reduced, and the damage to the light-emitting layer by the process is further reduced, so as to improve the yield of the display panel.

[0114] It should be noted that, although the above embodiments have been described in this article, the patent protection scope of the present invention is not limited thereby. Therefore, based on the innovative concept of the present invention, changes and modifications made to the embodiments described herein, or equivalent structures or equivalent process changes made using the contents of the present invention specification and drawings, directly or indirectly applying the above technical solutions to other related technical fields, are all included in the patent protection scope of the present invention.

Claims

1. A method for manufacturing a double-sided display panel, characterized in that: The steps include: Fabricating thin film transistors on a substrate; An insulating layer covering the thin film transistor is formed on the thin film transistor, and a through hole connected to the thin film transistor is formed on the insulating layer; A first reflective layer is formed on the insulating layer, and the first reflective layer is connected to the thin film transistor through a through hole on the insulating layer; Depositing an anode material to form a transparent anode on the insulating layer, the anode covers the first reflective layer, and the anode also has a portion on the insulating layer; A pixel definition layer is formed on the anode and the insulating layer, and a through hole connected to the anode is formed on the pixel definition layer; An organic light emitting layer is fabricated in a through hole connected to the anode on the pixel definition layer; Depositing cathode material to form a cathode covering the organic light-emitting layer on the pixel definition layer and the organic light-emitting layer, wherein the cathode is transparent; Forming a second reflective layer on the cathode in the organic light-emitting layer region, wherein the second reflective layer is located on one side of the first reflective layer; When making a through hole connected to the anode on the pixel definition layer, the following steps are also included: Two through holes connected to the anode are made on the pixel definition layer, the two through holes are not connected, the bottom of one through hole is the anode on the first reflective layer, and the bottom of the other through hole is the anode on the insulating layer; Before depositing the anode material, the following steps are also included: A window is made on the insulating layer on one side of the first reflective layer, the anode covers the window of the insulating layer and the first reflective layer, and the second reflective layer is at the window.

2. The method for manufacturing a double-sided display panel according to claim 1, characterized in that: When the second reflective layer is formed on the cathode in the organic light-emitting layer region, the following steps are also included: A second reflective layer is made on the cover plate, and then the side of the cover plate having the second reflective layer is covered on the cathode, so that the second reflective layer is connected to the cathode.

3. The method for manufacturing a double-sided display panel according to claim 1, characterized in that: The insulating layer includes a passivation layer and a planarization layer, and the planarization layer is disposed on the passivation layer.

4. A double-sided display panel, characterized in that: include: A thin film transistor is arranged on the substrate; An insulating layer covering the thin film transistor is arranged on the thin film transistor, and a through hole connected to the thin film transistor is arranged on the insulating layer; A first reflective layer is arranged on the insulating layer, and the first reflective layer is connected to the thin film transistor through a through hole on the insulating layer; A transparent anode is arranged on the insulating layer, the anode covers the first reflective layer, and the anode also has a portion on the insulating layer; A pixel definition layer is arranged on the anode and the insulating layer, and a through hole connected to the anode is arranged on the pixel definition layer; An organic light emitting layer is arranged in a through hole connected to the anode on the pixel definition layer; A cathode covering the organic light-emitting layer is arranged on the pixel definition layer and the organic light-emitting layer, and the cathode is transparent; A second reflective layer is disposed on the cathode of the organic light-emitting layer region, and the second reflective layer is located on one side of the first reflective layer; There are two through holes connected to the anode on the pixel definition layer, the two through holes are not connected, the bottom of one through hole is the anode on the first reflective layer, and the bottom of the other through hole is the anode on the insulating layer; A window is arranged on the insulating layer on one side of the first reflective layer, the anode covers the window of the insulating layer and the first reflective layer, and the second reflective layer is at the window.

5. The double-sided display panel according to claim 4, characterized in that: A cover plate is also included, the second reflective layer is arranged on the cover plate, and the side of the cover plate having the second reflective layer is covered on the cathode, so that the second reflective layer is connected to the cathode.

6. The double-sided display panel according to claim 4, characterized in that: The insulating layer includes a passivation layer and a planarization layer, and the planarization layer is disposed on the passivation layer.

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