Organic light emitting diode display panel and its manufacturing method

Abstract

An organic light emitting diode display panel and a manufacturing method thereof, the organic light emitting diode display panel including a substrate, a thin film transistor element, an auxiliary electrode, a passivation layer, a planarization layer, and a light emitting element layer, the light emitting element layer including an anode layer, a light emitting functional layer, and a cathode layer, a first via hole penetrating the planarization layer and the passivation layer is defined above the auxiliary electrode, a notch is formed at a bottom of an inner wall of the first via hole and positioned between the auxiliary electrode and the planarization layer, and the cathode layer extends into the notch through the first via hole to contact the auxiliary electrode.

Description

[Technical field]

[0001] The present invention relates to the technical field of displays, and in particular to an organic light-emitting diode display panel and a method for manufacturing the organic light-emitting diode display panel. [Background technology]

[0002] An organic light-emitting diode (OLED) display panel structure includes a transparent anode layer, a light-emitting layer, and a metal cathode layer. In order to improve the transmittance of a top-emitting device, the metal cathode layer is usually thinned, which increases the wiring resistance of the metal cathode layer, causing a serious current drop (IR-drop) problem, and the brightness unevenness phenomenon of the OLED display panel becomes prominent, which seriously affects the display effect of the OLED display panel. In order to improve the brightness unevenness problem of the display of the OLED display panel, an auxiliary electrode connected to the thin metal cathode layer is generally provided. By providing this auxiliary electrode, the IR-drop problem can be improved, and the brightness uniformity of the OLED display panel can be improved to a certain extent. In this manner, in the method of connecting the auxiliary electrode to the thin metal cathode layer, a spacer is generally provided between the cathode layer and the auxiliary electrode. However, the volume occupancy of the spacer is large, which affects the thickness, aperture ratio, and sealing of the OLED display panel. In addition, the selectivity of the spacer material is low, and an additional manufacturing process is usually required, which complicates the manufacturing process of the OLED display panel and reduces the manufacturing efficiency. Summary of the Invention [Problem to be solved by the invention]

[0003] In order to improve the IR-drop problem, the conventional OLED display panel must be provided with an auxiliary electrode and a spacer. However, the volume occupancy of the spacer is large, which affects the thickness, aperture ratio, and sealing of the OLED display panel. There is a need to improve the above technical problems. [Means for solving the problem]

[0004] In order to solve the above technical problems, the present invention provides an organic light emitting diode display panel and a manufacturing method thereof. The present invention forms a notch between the planarization layer above the auxiliary electrode and the passivation layer, i.e., the planarization layer is used as a support structure for the notch, so that the cathode layer can be bonded to the auxiliary electrode at the notch, and it has been experimentally verified that the IR drop problem of the organic light emitting diode display panel is improved and the planarization layer does not collapse. In addition, the present invention uses a three-layer molybdenum titanium / copper / molybdenum titanium alloy structure for the auxiliary electrode and the signal input pad in the same layer as the auxiliary electrode, so that the signal input pad can be directly connected to the control unit without providing a support layer above the signal input pad, and one mask can be omitted.

[0005] The present invention provides an organic light emitting diode display panel including: a substrate; a thin film transistor element provided on the substrate, the thin film transistor element including an active layer, a gate layer, a source, and a drain; an auxiliary electrode provided in the same layer as the source and the drain; a passivation layer provided on the source, the drain, and the auxiliary electrode; a planarization layer provided on the passivation layer; and a light emitting element layer provided on the planarization layer, the light emitting element layer including an anode layer, a light emitting functional layer, and a cathode layer, wherein a first via hole penetrating the planarization layer and the passivation layer is defined above the auxiliary electrode, a notch is formed at a bottom of an inner wall of the first via hole and positioned between the auxiliary electrode and the planarization layer, and the cathode layer extends into the notch through the first via hole to contact the auxiliary electrode.

[0006] The organic light emitting diode display panel according to one embodiment of the present invention further includes a buffer layer provided between the substrate and the thin film transistor element, an interlayer dielectric layer provided on the buffer layer, and a signal input pad provided on the interlayer dielectric layer, and an opening is defined in the passivation layer above the signal input pad to expose the signal input pad.

[0007] The organic light emitting diode display panel according to one embodiment of the present invention further includes a gate insulating layer provided between the gate layer and the active layer, and a light-shielding metal layer provided on the substrate corresponding to the active layer.

[0008] In an organic light emitting diode display panel according to one embodiment of the present invention, the anode layer contacts the source through a second via hole penetrating the planarization layer and the passivation layer, the source contacts the active layer through a third via hole penetrating the interlayer dielectric layer, and the source contacts the light-shielding metal layer through a fourth via hole penetrating the interlayer dielectric layer and the buffer layer.

[0009] The organic light emitting diode display panel according to one embodiment of the present invention further includes a first electrode disposed adjacent to the light-shielding metal layer and electrically connected to the light-shielding metal layer, and a second electrode disposed adjacent to the active layer and corresponding to the first electrode to form a storage capacitance.

[0010] In the organic light emitting diode display panel according to an embodiment of the present invention, the first electrode and the second electrode are made of indium gallium zinc oxide.

[0011] In the organic light emitting diode display panel according to an embodiment of the present invention, the planarization layer has a thickness of 1 to 4 micrometers.

[0012] In the organic light emitting diode display panel according to an embodiment of the present invention, the auxiliary electrodes and the signal input pads are made of a MoTi / Cu / MoTi alloy.

[0013] The present invention further provides another organic light emitting diode display panel including: a substrate; a thin film transistor element provided on the substrate, the thin film transistor element including an active layer, a gate layer, a source, and a drain; an auxiliary electrode provided in the same layer as the source and the drain; a passivation layer provided on the source, the drain, and the auxiliary electrode; a planarization layer provided on the passivation layer and having a thickness of 1 micrometer to 4 micrometers; and a light emitting element layer provided on the planarization layer, the light emitting element layer including an anode layer, a light emitting functional layer, and a cathode layer, wherein a first via hole penetrating the planarization layer and the passivation layer is defined above the auxiliary electrode, a notch is formed at a bottom of an inner wall of the first via hole and located between the auxiliary electrode and the planarization layer, the cathode layer extends into the notch through the first via hole and contacts the auxiliary electrode, the light emitting functional layer covers an area of ​​a portion of the auxiliary electrode corresponding to the first via hole, and the cathode layer covers an area of ​​another portion of the auxiliary electrode located in the notch.

[0014] The organic light emitting diode display panel according to an embodiment of the present invention further includes a buffer layer provided between the substrate and the thin film transistor element, and an interlayer dielectric layer provided on the buffer layer.

[0015] The organic light emitting diode display panel according to one embodiment of the present invention further includes a signal input pad provided on the interlayer dielectric layer, and an opening is defined in the passivation layer above the signal input pad to expose the signal input pad.

[0016] The organic light emitting diode display panel according to one embodiment of the present invention further includes a gate insulating layer provided between the gate layer and the active layer, and a light-shielding metal layer provided on the substrate corresponding to the active layer.

[0017] In an organic light emitting diode display panel according to one embodiment of the present invention, the anode layer contacts the source through a second via hole penetrating the planarization layer and the passivation layer, the source contacts the active layer through a third via hole penetrating the interlayer dielectric layer, and the source contacts the light-shielding metal layer through a fourth via hole penetrating the interlayer dielectric layer and the buffer layer.

[0018] The organic light emitting diode display panel according to one embodiment of the present invention further includes a first electrode disposed adjacent to the light-shielding metal layer and electrically connected to the light-shielding metal layer, and a second electrode disposed adjacent to the active layer and corresponding to the first electrode to form a storage capacitance.

[0019] In the organic light emitting diode display panel according to an embodiment of the present invention, the first electrode and the second electrode are made of indium gallium zinc oxide.

[0020] In the organic light emitting diode display panel according to an embodiment of the present invention, the auxiliary electrodes and the signal input pads are made of a MoTi / Cu / MoTi alloy.

[0021] The present invention provides a method for manufacturing a thin film transistor device, comprising the steps of: providing a substrate; fabricating a thin film transistor element and an auxiliary electrode on the substrate; sequentially fabricating a passivation layer and a planarization layer on the thin film transistor element and the auxiliary electrode; defining a first via hole penetrating the planarization layer above the auxiliary electrode, and defining a second via hole penetrating the planarization layer and the passivation layer above a source of the thin film transistor element; fabricating an anode layer on the planarization layer, the anode layer contacting the source through the second via hole; and forming a notch between the auxiliary electrode and the planarization layer. fabricating a pixel definition layer on the planarization layer to define a light-emitting region and a notch formation region; fabricating a light-emitting functional layer on the substrate and allowing the light-emitting functional layer to cover only an area of ​​a portion of the auxiliary electrode corresponding to the first via hole in the first via hole; fabricating a cathode layer on the light-emitting functional layer and allowing the cathode layer to extend to cover another area of ​​the auxiliary electrode located in the notch.

[0022] In one embodiment of the present invention, a method for manufacturing an organic light emitting diode display panel includes manufacturing a cathode layer on the light emitting functional layer, and extending the cathode layer to cover an area of ​​the auxiliary electrode located in the notch by changing an evaporation angle of an evaporation source. Effect of the Invention

[0023] In the present invention, a notch is formed between the planarization layer above the auxiliary electrode and the passivation layer, that is, the planarization layer is used as a support structure for the notch, so that the cathode layer can contact the auxiliary electrode at the notch, and it has been experimentally verified that the IR Drop problem of the organic light-emitting diode display panel is improved and the planarization layer does not collapse. In addition, in the present invention, the auxiliary electrode and the signal input pad in the same layer as the auxiliary electrode are made to have a three-layer molybdenum titanium / copper / molybdenum titanium alloy structure, so that the signal input pad can be directly connected to the control unit without providing a pad to protect the signal input pad above the signal input pad, and one mask can be omitted. In addition, in the present invention, a storage capacitor is provided on the thin film transistor element side, and the source is connected to the active layer through a third via hole penetrating the interlayer dielectric layer, and the source is connected to the light-shielding metal layer through a fourth via hole penetrating the interlayer dielectric layer and the buffer layer, thereby conducting the first electrode and the source and drain of the thin film transistor element, and enhancing the effect of the storage capacitor. Therefore, the current stabilization of the organic light-emitting diode display panel can be further maintained. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a schematic cross-sectional view of an organic light-emitting diode display panel according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic cross-sectional view of an organic light-emitting diode display panel according to a second embodiment of the present invention. [Diagram 3] FIG. 3 is a diagram showing a flow of a method for manufacturing an organic light emitting diode display panel according to an embodiment of the present invention. [Figure 4] FIG. 4 is a flow diagram showing step 9 of the method for manufacturing the organic light emitting diode display panel of FIG. 3 according to the present invention. [Diagram 5] FIG. 5 is a SEM cross-sectional photograph of the organic light emitting diode display panel according to the first embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, an organic light emitting diode display panel and a manufacturing method of an organic light emitting diode display panel according to an embodiment of the present invention will be described in detail with reference to the drawings. It is clear that the described embodiments are not all embodiments, but only some embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments that can be obtained by a person skilled in the art without creative labor are all within the scope of protection of the present invention.

[0026] Hereinafter, in order to illustrate specific embodiments for carrying out the present invention, each embodiment will be described with reference to the attached drawings. Directional terms referred to in the present invention, such as [upper], [lower], [front], [rear], [left], [right], [inner], [outer], and "side" are merely directions with reference to the drawings. Therefore, directional terms are used to explain and understand the present invention, and are not intended to limit the present invention. In the drawings, the thickness of some layers and the number and dimensions of some components are exaggerated for clarity and ease of explanation. In other words, the number, dimensions, and thickness of each component shown in the drawings are arbitrarily shown, but the present invention is not limited thereto.

[0027] Please refer to FIG. 1. FIG. 1 is a schematic cross-sectional view of an organic light-emitting diode display panel according to a first embodiment of the present invention. As shown in FIG. 1, an organic light-emitting diode display panel 10 according to a first embodiment of the present invention includes a substrate 100, a thin film transistor element 301, an auxiliary electrode 401, a passivation layer 400, a planarization layer 500, a pixel definition layer 600, and a light-emitting element layer (701, 702, 703). A thin film transistor element 301 is disposed on the substrate 100, and the thin film transistor element 301 includes an active layer 3011, a gate layer 3013, a source 3014, and a drain 3015. An auxiliary electrode 401 is disposed in the same layer as the source 3014 and the drain 3015. A passivation layer 400 is disposed on the source 3014, the drain 3015, and the auxiliary electrode 401. A planarization layer 500 is disposed on the passivation layer 400. A pixel definition layer 600 is disposed on the planarization layer 500. A light emitting element layer (701, 702, 703) is provided on the planarization layer 500 and the pixel definition layer 600. The light emitting element layer (701, 702, 703) includes an anode layer 701, a light emitting functional layer 702, and a cathode layer 703. A first via hole H1 penetrating the planarization layer 500 and the passivation layer 400 is defined above the auxiliary electrode 401, and a notch U located between the auxiliary electrode 401 and the planarization layer 500 is formed at the bottom of the inner wall of the first via hole H1. The cathode layer 703 extends into the notch U through the first via hole H1 and contacts the auxiliary electrode 401. Specifically, the substrate 100 is a light transmissive substrate made of a glass material. Specifically, the constituent material of the passivation layer 400 may be silicon nitride or silicon oxide, and the thickness may be 2000 angstroms to 2500 angstroms. Specifically, the material of the planarization layer 500 may be a polymer adhesive, and the thickness of the planarization layer 500 may be 1 micrometer to 4 micrometers. Specifically, the material of the active layer 3011 may be indium gallium zinc oxide (IGZO).

[0028] Preferably, the organic light emitting diode display panel 10 further includes a buffer layer 200, an interlayer dielectric layer 300, and a signal input pad 402. The interlayer dielectric layer 300 is disposed on the buffer layer 200, and the signal input pad 402 is disposed on the interlayer dielectric layer 300. In order to expose the signal input pad 402, the passivation layer 400 defines an opening 403 above the signal input pad 402. Specifically, the signal input pad 402 is bonded to a control unit such as a flexible circuit board (chip on film, COF) when the module is bonded, and transmits a signal into the organic light emitting diode display panel 10 through the external COF. That is, the signal input pad 402 plays a role of connecting the COF and the organic light emitting diode display panel 10 and inputting a signal to the organic light emitting diode display panel 10.

[0029] A buffer layer 200 is provided between the substrate 100 and the thin film transistor element 301. An interlayer dielectric layer 300 is provided on the buffer layer 200. Preferably, the planarization layer 500 has a thickness of 1 micrometer to 4 micrometers.

[0030] Preferably, the organic light emitting diode display panel 10 further includes a gate insulating layer 3012 disposed between the gate layer 3013 and the active layer 3011 , and a light-shielding metal layer 201 disposed on the substrate 100 corresponding to the active layer 3011 .

[0031] Specifically, the buffer layer 200 may be selected from materials having a buffer function, such as rubber, white rubber, silicone rubber, or thermally conductive rubber. Specifically, in order to obtain a relatively flat surface, the interlayer dielectric layer 300 is formed by chemical vapor deposition (CVD) or spin coating, and the material includes an organic material (e.g., polyimide) or an inorganic material (e.g., silicon oxide, phosphosilicate glass, and borosilicate glass). Preferably, the constituent material of the signal input pad 402 may be a molybdenum titanium / copper / molybdenum titanium alloy. In this embodiment, the signal input pad uses a three-layer molybdenum titanium / copper / molybdenum titanium alloy structure, so that the signal input pad can be directly connected to the control unit without providing a support layer above the signal input pad, and one mask can be omitted, which can reduce the manufacturing cost.

[0032] In this embodiment, a notch U is formed between the planarization layer 500 above the auxiliary electrode 401 and the passivation layer 400, i.e., the planarization layer 500 is directly used as a support structure for the notch U, so that the cathode layer 703 can be bonded to the auxiliary electrode 401 at the notch U, which improves the IR Drop problem of the organic light emitting diode display panel and prevents the planarization layer 500 from collapsing.

[0033] Please refer to FIG. 2. FIG. 2 is a schematic cross-sectional view of an organic light-emitting diode display panel according to a second embodiment of the present invention. As shown in FIG. 2, the organic light-emitting diode display panel 10' according to the second embodiment of the present invention includes a substrate 100, a thin film transistor element 301, an auxiliary electrode 401, a passivation layer 400, a planarization layer 500, and a light-emitting element layer (701, 702, 703). The thin film transistor element 301 is disposed on the substrate 100, and the thin film transistor element 301 includes an active layer 3011, a gate layer 3013, a source 3014, and a drain 3015. The auxiliary electrode 401 is disposed in the same layer as the source 3014 and the drain 3015. The passivation layer 400 is disposed on the source 3014, the drain 3015, and the auxiliary electrode 401. The planarization layer 500 is disposed on the passivation layer 400. A light-emitting element layer (701, 702, 703) is provided on the planarization layer 500, and the light-emitting element layer (701, 702, 703) includes an anode layer 701, a light-emitting functional layer 702, and a cathode layer 703. A first via hole H1 penetrating the planarization layer 500 and the passivation layer 400 is defined above the auxiliary electrode 401, and a notch U located between the auxiliary electrode 401 and the planarization layer 500 is formed at the bottom of the inner wall of the first via hole H1. The cathode layer 703 extends into the notch U through the first via hole H1 and contacts the auxiliary electrode 401, the light-emitting functional layer 702 covers an area of ​​a portion of the first via hole H1 that corresponds to the first via hole H1 of the auxiliary electrode 401, and the cathode layer 703 covers the area of ​​the other portion located within the notch U of the auxiliary electrode 401.

[0034] Specifically, the substrate 100 is a light-transmitting substrate made of a glass material. Specifically, the passivation layer 400 may be made of silicon nitride or silicon oxide and may have a thickness of 2000 angstroms to 2500 angstroms. Specifically, the planarization layer 500 may be made of a polymer adhesive and may have a thickness of 1 micrometer to 4 micrometers. Specifically, the active layer 3011 may be made of indium gallium zinc oxide (IGZO).

[0035] Preferably, the organic light-emitting diode display panel 10' further includes a gate insulating layer 3012 provided between the gate layer 3013 and the active layer 3011, and a light-shielding metal layer 201 provided on the substrate 100 corresponding to the active layer 3011. Preferably, the organic light-emitting diode display panel 10' further includes a buffer layer 200, an interlayer dielectric layer 300, and a signal input pad 402. The interlayer dielectric layer 300 is provided on the buffer layer 200, and the signal input pad 402 is provided on the interlayer dielectric layer 300. An opening 403 is defined in the passivation layer 400 above the signal input pad 402 to expose the signal input pad 402. Specifically, the signal input pad 402 is bonded to a control unit such as a flexible circuit board (chip on film, COF) during module bonding, and a signal is transmitted into the organic light-emitting diode display panel 10' through the external COF. That is, the signal input pad 402 connects the COF and the organic light emitting diode display panel 10' to input a signal to the organic light emitting diode display panel 10'. The buffer layer 200 is provided between the substrate 100 and the thin film transistor element 301. The interlayer dielectric layer 300 is provided on the buffer layer 200. Preferably, the planarization layer 500 has a thickness of 1 to 4 micrometers.

[0036] Compared with the organic light emitting diode display panel 10 according to the first embodiment of the present invention, the organic light emitting diode display panel 10' according to the second embodiment of the present invention further includes a first electrode 202 disposed adjacent to the light-shielding metal layer 201 and electrically connected to the light-shielding metal layer 201, and a second electrode 302 disposed adjacent to the active layer 3011 and corresponding to the first electrode 202 to form a storage capacitance C.

[0037] Preferably, the first electrode 202 and the second electrode 302 are made of indium gallium zinc oxide.

[0038] Preferably, the anode layer 701 contacts the source 3014 through a second via hole H2 that penetrates the planarization layer 500 and the passivation layer 400, the source 3014 contacts the active layer 3011 through a third via hole H3 that penetrates the interlayer dielectric layer 300, and the source 3014 contacts the light-shielding metal layer 201 through a fourth via hole H4 that penetrates the interlayer dielectric layer 300 and the buffer layer 200.

[0039] In this embodiment, a notch U is formed between the planarization layer 500 above the auxiliary electrode 401 and the passivation layer 400, i.e., the planarization layer 500 is used as a support structure for the notch U, so that the cathode layer 703 can be bonded to the auxiliary electrode 401 at the notch U, thereby improving the problem of IR Drop in the organic light-emitting diode display panel. Also, in this embodiment, a storage capacitor C is provided on the thin film transistor element 301 side, and the source is connected to the active layer through a third via hole penetrating the interlayer dielectric layer, and the source is connected to the light-shielding metal layer through a fourth via hole penetrating the interlayer dielectric layer and the buffer layer, thereby conducting the first electrode (provided in the same layer as the light-shielding metal layer and conducting) and the source / drain of the thin film transistor element 301, thereby enhancing the effect of the storage capacitor. In this embodiment, a storage capacitor is provided on the side of the adjacent thin film transistor element, and the source is connected to the active layer through a third via hole penetrating the interlayer dielectric layer, and the source is connected to the light-shielding metal layer through a fourth via hole penetrating the interlayer dielectric layer and the buffer layer, thereby electrically connecting the first electrode and the source and drain of the thin film transistor element, thereby enhancing the effect of the storage capacitor, and further maintaining the current stabilization of the organic light emitting diode display panel.

[0040] Please refer to Fig. 3. Fig. 3 is a diagram showing a flow of a method for manufacturing an organic light emitting diode display panel according to an embodiment of the present invention. As shown in Fig. 3, the flow of the method for manufacturing an organic light emitting diode display panel according to an embodiment of the present invention includes step S1 of providing a substrate, step S2 of manufacturing a thin film transistor element and an auxiliary electrode on the substrate, step S3 of sequentially manufacturing a passivation layer and a planarization layer on the thin film transistor element and the auxiliary electrode, step S4 of defining a first via hole penetrating the planarization layer above the auxiliary electrode and defining a second via hole penetrating the planarization layer and the passivation layer above the source of the thin film transistor element, step S5 of manufacturing an anode layer on the planarization layer, and step S6 of contacting the anode layer with the source through the second via hole. 5, step S6 of wet etching the passivation layer in the first via hole to form a notch between the auxiliary electrode and the planarization layer, step S7 of fabricating a pixel definition layer on the planarization layer to define a light-emitting area LA and a notch area UA (as shown in FIG. 1 ), step S8 of fabricating a light-emitting functional layer on the substrate and causing the light-emitting functional layer to cover only the area of ​​a portion of the auxiliary electrode in the first via hole corresponding to the first via hole, and step S9 of fabricating a cathode layer on the light-emitting functional layer and allowing the cathode layer to extend to cover the area of ​​the other portion located in the notch of the auxiliary electrode.

[0041] Specifically, in step S6, the passivation layer in the first via hole is wet-etched with hydrofluoric acid (HF) so as to form a notch between the auxiliary electrode and the planarization layer. During the etching, the other areas except for the notch forming area are protected by resist and are not affected by the etching solution.

[0042] Specifically, in step S7, a pixel definition layer is fabricated on the planarization layer to define the light-emitting area and the notch formation area, and the resist of the pixel definition layer in the notch formation area below the planarization layer can be removed by an exposure and development process.

[0043] Specifically, in step S8, the light-emitting functional layer is formed by a deposition method, and the deposition angle of the deposition source is controlled so that the light-emitting functional layer covers only the area of ​​the portion of the first via hole that corresponds to the first via hole of the auxiliary electrode.

[0044] Please refer to Fig. 4. Fig. 4 is a diagram showing the flow of step 9 of the method for manufacturing the organic light-emitting diode display panel of Fig. 3 according to the present invention. As shown in Fig. 4 (also see Fig. 2), in step S9, the cathode layer of the organic light-emitting diode display panel 10' is formed by a deposition method, and the deposition angle of the deposition source S is controlled to make the cathode layer extend to cover the area PA of the portion located within the notch U of the auxiliary electrode 401.

[0045] Finally, please refer to FIG. 5. FIG. 5 is a scanning electron microscope (SEM) cross-sectional photograph of the organic light-emitting diode display panel according to the first embodiment of the present invention. As shown in FIG. 5, in the first and second embodiments of the present invention, a notch U is formed between the planarization layer 500 above the auxiliary electrode 401 and the passivation layer 400, that is, the planarization layer 500 is directly used as a support structure for the notch U, so that the cathode layer (not shown in the photograph) can be bonded to the auxiliary electrode at the notch U, improving the IR Drop problem of the organic light-emitting diode display panel, and it has been experimentally verified that the planarization layer 500 does not collapse.

[0046] As described above, the above embodiment of the present invention forms a notch between the planarization layer above the auxiliary electrode and the passivation layer, i.e., by using the planarization layer as a support structure for the notch, the cathode layer can contact the auxiliary electrode at the notch, and it has been experimentally verified that the IR Drop problem of the organic light-emitting diode display panel is improved and the planarization layer does not collapse. In addition, the present invention uses a three-layer molybdenum titanium / copper / molybdenum titanium alloy structure for the auxiliary electrode and the signal input pad in the same layer as the auxiliary electrode, so that the signal input pad can be directly connected to the control unit without providing a pad to protect the signal input pad above the signal input pad, and one mask can be omitted. In addition, the present invention provides a storage capacitance on the thin film transistor element side, connects the source to the active layer through a third via hole penetrating the interlayer dielectric layer, and connects the source to the light-shielding metal layer through a fourth via hole penetrating the interlayer dielectric layer and the buffer layer, thereby conducting the first electrode and the source-drain of the thin film transistor element, and enhancing the effect of the storage capacitance. Therefore, the current stabilization of the organic light-emitting diode display panel can be further maintained.

[0047] It should be noted that the above is merely a preferred embodiment of the present invention, and those skilled in the art may make further improvements and modifications without departing from the spirit of the present invention, and these improvements and modifications should also be considered as within the protection scope of the present invention.

Claims

1. A substrate; a thin film transistor element provided on the substrate, the thin film transistor element including an active layer, a gate layer, a source layer, and a drain layer; an auxiliary electrode provided in the same layer as the source and the drain; a passivation layer provided on the source, drain and auxiliary electrodes; a planarization layer disposed on the passivation layer; a pixel definition layer disposed on the planarization layer; a light-emitting element layer including an anode layer, a light-emitting functional layer, and a cathode layer; a first via hole penetrating the planarization layer and the passivation layer is defined above the auxiliary electrode, a notch is formed at a bottom of an inner wall of the first via hole between the auxiliary electrode and the planarization layer, the light emitting element layer is provided above the first via hole, and an edge of the planarization layer protrudes beyond an edge of the pixel definition layer at the notch; The cathode layer extends into the notch through the first via hole and contacts the auxiliary electrode.

2. a buffer layer provided between the substrate and the thin film transistor element; an interlayer dielectric layer disposed on the buffer layer; a signal input pad disposed on the interlevel dielectric layer; 2. The organic light emitting diode display panel of claim 1, wherein the passivation layer defines an opening above the signal input pad to expose the signal input pad.

3. a gate insulating layer provided between the gate layer and the active layer; The organic light emitting diode display panel of claim 2 , further comprising: a light-shielding metal layer disposed on the substrate in correspondence with the active layer.

4. 4. The organic light-emitting diode display panel of claim 3, wherein the anode layer contacts the source through a second via hole penetrating the planarization layer and the passivation layer, the source contacts the active layer through a third via hole penetrating the interlayer dielectric layer, and the source contacts the light-shielding metal layer through a fourth via hole penetrating the interlayer dielectric layer and the buffer layer.

5. a first electrode provided adjacent to the light-shielding metal layer and electrically connected to the light-shielding metal layer; 5. The organic light emitting diode display panel of claim 4, further comprising: a second electrode disposed adjacent to the active layer and corresponding to the first electrode to form a storage capacitance.

6. 6. The organic light emitting diode display panel of claim 5, wherein the first electrode and the second electrode are made of indium gallium zinc oxide.

7. 2. The organic light-emitting diode display panel according to claim 1, wherein the thickness of the planarization layer is from 1 to 4 micrometers.

8. 3. The organic light-emitting diode display panel according to claim 2, wherein the auxiliary electrodes and the signal input pads are made of a molybdenum titanium / copper / molybdenum titanium alloy.

9. the thickness of the planarization layer is between 1 micrometer and 4 micrometers; 2. The organic light-emitting diode display panel of claim 1, wherein the light-emitting functional layer covers an area of ​​the auxiliary electrode corresponding to the first via hole, and the cathode layer covers an area of ​​the auxiliary electrode other than the area of ​​the auxiliary electrode corresponding to the first via hole located in the notch of the auxiliary electrode.

10. a buffer layer provided between the substrate and the thin film transistor element; 10. The organic light emitting diode display panel of claim 9, further comprising: an interlayer dielectric layer disposed on the buffer layer.

11. a signal input pad disposed on the interlevel dielectric layer; 11. The organic light emitting diode display panel of claim 10, wherein the passivation layer defines an opening above the signal input pad to expose the signal input pad.

12. a gate insulating layer provided between the gate layer and the active layer; The organic light emitting diode display panel of claim 11, further comprising: a light-shielding metal layer disposed on the substrate corresponding to the active layer.

13. 13. The organic light-emitting diode display panel of claim 12, wherein the anode layer contacts the source through a second via hole penetrating the planarization layer and the passivation layer, the source contacts the active layer through a third via hole penetrating the interlayer dielectric layer, and the source contacts the light-shielding metal layer through a fourth via hole penetrating the interlayer dielectric layer and the buffer layer.

14. a first electrode provided adjacent to the light-shielding metal layer and electrically connected to the light-shielding metal layer; The organic light emitting diode display panel of claim 13, further comprising: a second electrode disposed adjacent to the active layer and corresponding to the first electrode to form a storage capacitance.

15. 15. The organic light emitting diode display panel of claim 14, wherein the first electrode and the second electrode are made of indium gallium zinc oxide.

16. 10. The organic light-emitting diode display panel of claim 9, wherein the auxiliary electrode is made of a molybdenum titanium / copper / molybdenum titanium alloy.

17. Providing a substrate; fabricating a thin film transistor element and an auxiliary electrode on the substrate; sequentially fabricating a passivation layer and a planarization layer on the thin film transistor element and the auxiliary electrode; defining a first via hole penetrating the planarization layer above the auxiliary electrode, and defining a second via hole penetrating the planarization layer and the passivation layer above a source of the thin film transistor element; fabricating an anode layer on the planarization layer, the anode layer contacting the source through the second via hole; wet etching the passivation layer in the first via hole to form a notch between the auxiliary electrode and the planarization layer; fabricating a pixel definition layer on the planarization layer to define a light emitting area and a cutout forming area, the edges of the planarization layer protruding beyond the edges of the pixel definition layer at the cutout; fabricating a light emitting device layer above the first via hole; Producing a light emitting functional layer on the substrate, and allowing the light emitting functional layer to cover only an area of ​​the auxiliary electrode corresponding to the first via hole in the first via hole; fabricating a cathode layer on the light-emitting functional layer and extending the cathode layer to cover an area of ​​the auxiliary electrode other than an area of ​​a portion of the auxiliary electrode located in the notch and corresponding to the first via hole; and extending the cathode layer into the notch through the first via hole to contact the auxiliary electrode.

18. 18. The method of claim 17, wherein the step of extending the cathode layer to cover an area of ​​the portion of the auxiliary electrode located in the notch is performed by changing a deposition angle of a deposition source.

Images