Multiple overhangs against enhanced pixel encapsulation

Abstract

Embodiments described herein relate to a device comprising a substrate, a plurality of protruding structures, and a plurality of subpixels. The plurality of protruding structures include a first structure, a second structure disposed on the upper surface of the first structure, an adjacent first protrusion, a third structure disposed on the second structure, and an adjacent second protrusion. Each first protrusion is defined by a first protrusion extension of the second structure that extends laterally past the upper surface of the first structure. Each subpixel includes an anode, an organic light-emitting diode (OLED) material disposed on the anode, and a cathode disposed on the OLED material.

Description

Technical Field

[0001] The embodiments described herein generally relate to displays. More particularly, the embodiments described herein relate to sub-pixel circuits that may be utilized within a display, such as an organic light emitting diode (OLED) display, and methods of forming the sub-pixel circuits.

Background Art

[0002] Input devices including display devices may be used within various electronic systems. An organic light emitting diode (OLED) is a light emitting diode (LED) in which a light emitting electroluminescent layer is a film of an organic compound, and the film emits light in response to an electric current. When the emitted light passes through a transparent or translucent bottom electrode and a substrate on which a panel is manufactured, the OLED device is classified as a bottom-emitting device. A top-emitting device is classified based on whether the light emitted from the OLED device passes through a lid added after the manufacture of the device. OLEDs are currently used to fabricate display devices of many electronic devices. Today's electronic device manufacturers are pushing to reduce the size of these display devices while simultaneously providing higher resolutions than just a few years ago.

[0003] The patterning of OLED pixels is currently based on a process that limits panel size, pixel resolution, and substrate size. Instead of using a fine metal mask to pattern pixels, photolithography should be used. Currently, in the patterning of OLED pixels, it is necessary to strip the organic material after the patterning process. When stripped, the organic material causes particle problems that degrade OLED performance. Therefore, in the art, there is a need for sub-pixel circuits and methods of forming sub-pixel circuits that increase the number of pixels per inch and provide improved OLED performance.

Summary of the Invention

[0004] In one embodiment, a device is provided. This device includes a substrate, a plurality of protruding structures, and a plurality of subpixels. The plurality of protruding structures include a first structure, a second structure positioned on the upper surface of the first structure, an adjacent first protrusion, a third structure positioned on the second structure, and an adjacent second protrusion. Each first protrusion is defined by a first protruding extension of the second structure that extends laterally past the upper surface of the first structure. Each subpixel includes an anode, an organic light-emitting diode (OLED) material positioned on the anode, and a cathode positioned on the OLED material.

[0005] In another embodiment, a device is provided which includes a substrate, a plurality of protruding structures disposed on the substrate, and a plurality of subpixels. Each protruding structure includes a first structure, a second structure disposed on the upper surface of the first structure, an adjacent first protrusion, and an adjacent second protrusion. The second structure includes an internal plane, a top surface, an upper sidewall formed between the internal plane and the top surface, a bottom surface, and a lower sidewall formed between the internal plane and the bottom surface. Each first protrusion is defined by a first protruding extension of the second structure that extends laterally past the top surface of the first structure. Each second protrusion is formed by the upper sidewall. Each subpixel includes an anode, an organic light-emitting diode (OLED) material disposed on the anode, and a cathode disposed on the OLED material.

[0006] In another embodiment, a method is provided. This method includes depositing a first structural layer and a second structural layer on a substrate. Removing the resist-exposed portion of the second structural layer to form a second structure and a third structure. Removing the resist-exposed portion of the first structural layer to form a first structure. Removing the resist from the third structure. Depositing organic light-emitting diode (OLED) material, a cathode, and an encapsulation layer.

[0007] A more detailed description of the disclosure outlined above can be obtained by referring to embodiments, some of which are shown in the accompanying drawings, so that the features of the disclosure listed above can be understood in detail. However, it should be noted that the accompanying drawings show only exemplary embodiments and should not be considered limiting to the scope of the disclosure, and other equally valid embodiments may be accepted. [Brief explanation of the drawing]

[0008] [Figure 1A] This is a schematic cross-sectional view of a subpixel circuit according to an embodiment. [Figure 1B] This is a schematic cross-sectional view of a protruding subpixel circuit structure according to an embodiment. [Figure 1C] This is a schematic cross-sectional view of a subpixel circuit according to an embodiment. [Figure 1D] This is a schematic cross-sectional view of a protruding subpixel circuit structure according to an embodiment. [Figure 2] This is a schematic cross-sectional view of a protruding subpixel circuit structure according to an embodiment. [Figure 3] This is a schematic cross-sectional view of a protruding subpixel circuit structure according to an embodiment. [Figure 4] This is a schematic cross-sectional view of a protruding subpixel circuit structure according to an embodiment. [Figure 5] This is a schematic cross-sectional view of a protruding subpixel circuit structure according to an embodiment. [Figure 6] This is a schematic cross-sectional view of a protruding subpixel circuit structure according to an embodiment. [Figure 7] This is a flowchart of method 700 for forming a subpixel circuit. [Figure 8A] This is a schematic cross-sectional view of a substrate during a method for forming a subpixel circuit. [Figure 8B] This is a schematic cross-sectional view of a substrate during a method for forming a subpixel circuit. [Figure 8C]This is a schematic cross-sectional view of a substrate during a method for forming a subpixel circuit. [Figure 8D] This is a schematic cross-sectional view of a substrate during a method for forming a subpixel circuit. [Modes for carrying out the invention]

[0009] For ease of understanding, the same reference numerals are used to indicate identical elements common to the figures where possible. Elements disclosed in one embodiment are intended to be usefully utilized in other embodiments unless otherwise specified.

[0010] The embodiments described herein generally relate to displays. More specifically, the embodiments described herein relate to subpixel circuits that may be used in displays such as organic light-emitting diode (OLED) displays, and methods for forming subpixel circuits. In various embodiments, these subpixels use advanced protruding structures to enhance the functionality of the display.

[0011] Each of the embodiments of a subpixel circuit described herein includes a plurality of subpixels, each of which is defined by an adjacent protruding structure that is permanently present in the subpixel circuit. The figure shows two subpixels, each defined by an adjacent protruding structure, but the subpixel circuits of the embodiments described herein include a plurality of subpixels, such as two or more subpixels. Each subpixel has an OLED material configured to emit white, red, green, blue, or other colored light when energized. For example, the OLED material of the first subpixel emits red light when energized, the OLED material of the second subpixel emits green light when energized, and the OLED material of the third subpixel emits blue light when energized.

[0012] These protrusions are permanently present in the subpixel circuit and include at least a second structure positioned on top of the first structure. Adjacent protrusion structures defining each subpixel in the subpixel circuit of the display define the formation of the subpixel circuit using deposition and define that the protrusion structures remain in place after the subpixel circuit is formed. Deposition is used to deposit the OLED material and cathode (including the hole injection layer (HIL), hole transport layer (HTL), light emission layer (EML), and electron transport layer (ETL)). In some examples, encapsulation layers may be positioned by deposition. In embodiments including one or more capping layers, the capping layers are positioned between the cathode and the encapsulation layer. The encapsulation layer for each subpixel is positioned on top of the cathode.

[0013] Figure 1A is a schematic cross-sectional view of the first subpixel circuit 100A. Figure 1B is a schematic cross-sectional view of the protruding structure 110 of the first subpixel circuit 100A. The first subpixel circuit 100A includes a substrate 102. A metal-containing layer 104 may be patterned on the substrate 102, and the metal-containing layer 104 is defined by adjacent pixel structures (PS) 126A disposed on the substrate 102. In one embodiment, the PS 126A is disposed on the substrate 102. In one embodiment, the metal-containing layer 104 is pre-patterned on the substrate 102. For example, the substrate 102 is pre-patterned with an indium tin oxide (ITO) metal-containing layer 104. The metal-containing layer 104 is configured to act as the anode of each subpixel. In one embodiment, the metal-containing layer 104 is a layer stack of a first transparent conductive oxide (TCO) layer, a second metal-containing layer disposed on the first TCO layer, and a third TCO layer disposed on the second metal-containing layer. The metal-containing layer 104 includes, but is not limited to, chromium, titanium, gold, silver, copper, aluminum, ITO, combinations thereof, or other suitable conductive materials.

[0014] Multiple PS126A are arranged on a substrate 102. A PS126A comprises one of the following: an organic material, an organic material with an inorganic coating on which an inorganic coating is placed. The organic material of the PS126A includes, but is not limited to, polyimide. The inorganic material of the PS126A includes, but is not limited to, silicon oxide (SiO2), silicon nitride (Si3N4), silicon oxynitride (Si2N2O), magnesium fluoride (MgF2), or a combination thereof. Adjacent PS126A define their respective subpixels and expose the anode (i.e., the metal-containing layer 104) of their respective subpixel circuits 100.

[0015] The first subpixel circuit 100A has a plurality of subpixels 106, including at least a first subpixel 108A and a second subpixel 108B. While these figures show the first subpixel 108A and the second subpixel 108B, the first subpixel circuit 100A in the embodiments described herein may include two or more subpixels 106, such as third and fourth subpixels. Each subpixel 106 has an OLED material configured to emit white, red, green, blue, or other colored light when energized. For example, the OLED material of the first subpixel 108A emits red light when energized, the OLED material of the second subpixel 108B emits green light when energized, the OLED material of the third subpixel emits blue light when energized, and the OLED material of the fourth subpixel emits another colored light when energized.

[0016] Each subpixel 106 includes an overhang structure 110. The overhang structure 110 is resident in the first subpixel circuit 100A. The overhang structure 110 defines each subpixel 106 of the first subpixel circuit 100A. Each overhang structure 110 further includes an adjacent first overhang 117 and an adjacent second overhang 109. The adjacent first overhang is defined by a first overhang extension portion 117A of a second structure 110B (shown in FIG. 1B) that extends laterally past the upper surface 105 of the first structure 110A. The first structure 110A is disposed on the upper surfaces 103 of a plurality of adjacent PS126A (shown in FIG. 1B). The adjacent second overhang 109 extends laterally past the upper surface 115 of the second structure 110B and is defined by a second overhang extension portion 109A of a third structure 110C (shown in FIG. 1B). The third structure 110C is disposed on the second structure 110B.

[0017] In one embodiment, the second structure 110B and the third structure 110C include a non-conductive inorganic material, and the first structure 110A includes a conductive inorganic material. The conductive material of the first structure 110A includes aluminum (Al), aluminum neodymium (AlNd), molybdenum (Mo), molybdenum tungsten (MoW), copper (Cu), or a combination thereof. The inorganic materials of the second structure 110B and the third structure 110C include titanium (Ti), silicon nitride (Si3N4), silicon oxide (SiO2), silicon oxynitride (Si2N2O), or a combination thereof. The overhang structure 110 can stay in place. That is, the overhang structure 110 is resident. In one embodiment, the first structure 110A includes a metal-containing material. In one example, the metal-containing material is a transparent conductive oxide (TCO) material. The TCO material includes, but is not limited to, indium zinc oxide (IZO), indium tin oxide (ITO), indium gallium zinc oxide (IGZO), or a combination thereof. In another embodiment, the first structure 110A, the second structure 110B, and the third structure 110C include a conductive material.

[0018] The adjacent first overhang 117 is defined by a first overhang extension portion 117A. To form the first overhang extension portion 117A, at least the bottom surface 107 of the second structure 110B is wider than the top surface 105 of the first structure 110A. The first overhang extension portion 117A of the second structure 110B forms the first overhang 117, enabling the second structure 110B to shadow the first structure 110A. The shadowing of the first overhang 117 defines the deposition of the OLED material 112 and the cathode 114. The OLED material 112 may include one or more of HIL, HTL, EML, and ETL. The OLED material is disposed in contact with the metal-containing layer 104 on the metal-containing layer 104. The OLED material 112 is disposed under the adjacent first overhang 117. The cathode 114 includes a conductive material such as a metal. For example, the cathode 114 includes, but is not limited to, silver, magnesium, chromium, titanium, aluminum, ITO, or a combination thereof. The cathode 114 is disposed on the OLED material 112 and on the sidewalls of the second structure 110B of the overhang structure 110.

[0019] The adjacent second overhang 109 is defined by a second overhang extension portion 109A of the third structure 110C. To form the second overhang extension portion 109A of the second overhang 109, at least the bottom surface 121 of the third structure 110C is wider than the top surface 115 of the second structure 110B. The third structure 110C is disposed on the top surface 115 of the second structure 110B. The second overhang extension portion 109A of the third structure 110C forms the second overhang 109, enabling the third structure 110C to shadow the second structure 110B. The shadowing of the second overhang 109 defines the deposition of each of the OLED material 112 and the cathode 114. Each of the OLED material 112 and the cathode 114 is disposed under the second overhang 109.

[0020] The cathode 114 includes a conductive material such as a metal. For example, the cathode 114 includes, but is not limited to, silver, magnesium, chromium, titanium, aluminum, ITO, or a combination thereof. In one embodiment, the material of the cathode 114 is different from the material of the first structure 110A, the second structure 110B, and the third structure 110C. In some embodiments, the OLED material 112 and the cathode 114 are located on the side wall 111 of the first structure 110A. The OLED material 112 and the cathode 114 are not located on the side wall 123 of the second structure 110B or on the side wall 124 of the third structure 110C.

[0021] Each subpixel 106 includes an encapsulation layer 116. The encapsulation layer 116 may be a local passivation layer or equivalent. The encapsulation layer 116 of each subpixel is located on the cathode 114 (and OLED material 112), and the encapsulation layer 116 extends beneath at least a portion of each of the first protrusion 117 and the second protrusion 109. The encapsulation layer 116 comprises a non-conductive inorganic material, such as a silicon-containing material. This silicon-containing material may include a material containing Si3N4.

[0022] In embodiments including one or more capping layers, the capping layers are positioned between the cathode 114 and the encapsulation layer 116. For example, a first capping layer and a second capping layer are positioned between the cathode 114 and the encapsulation layer 116. Each of the embodiments described herein may include one or more capping layers positioned between the cathode 114 and the encapsulation layer 116. The first capping layer may contain an organic material. The second capping layer may contain an inorganic material such as lithium fluoride. The first and second capping layers may be deposited by vapor deposition. In another embodiment, the first subpixel circuit 100A further includes at least one broad-area passivation layer 120 positioned on the protruding structure 110 and the encapsulation layer 116. In yet another embodiment, the subpixel includes an intermediate passivation layer positioned on each of the protruding structures 110 of the subpixel 106 and between the encapsulation layer 116 and the broad-area passivation layer 120.

[0023] The encapsulation layer 116 is located within the adjacent second protrusion 109. Therefore, the adjacent second protrusion 109 stipulates a reduction in moisture intrusion into the protrusion structure 110. Due to the contact between the encapsulation layer 116 and the second structure 110B, the adjacent second protrusion 109 forms a more complex moisture intrusion pathway. When moisture intrudes into the protrusion structure 110, the encapsulation layer 116 within the adjacent second protrusion 109 forms a barrier between the moisture and the second structure 110B, thereby preventing moisture from intruding into the adjacent first protrusion 117.

[0024] Figure 1C is a schematic cross-sectional view of a second subpixel circuit 100B according to an embodiment. Figure 1D is a schematic cross-sectional view of a second subpixel circuit 100B according to an embodiment. The second subpixel circuit 100B includes a substrate 102. A base layer 125 may be patterned on the substrate 102. The base layer 125 includes, but is not limited to, a CMOS layer. A metal-containing layer 104 (e.g., an anode) may be patterned on the base layer 125, and the metal-containing layer 104 is defined by adjacent pixel structures (PS) 126B disposed on the substrate 102. In one embodiment, the metal-containing layer 104 is pre-patterned on the base layer 125. For example, the base layer 125 is pre-patterned with an indium tin oxide (ITO) metal-containing layer 104. The metal-containing layer 104 may be disposed on the substrate 102. The metal-containing layer 104 is configured to act as the anode of each subpixel. In one embodiment, the metal-containing layer 104 is a layer stack of a first transparent conductive oxide (TCO) layer, a second metal-containing layer disposed on the first TCO layer, and a third TCO layer disposed on the second metal-containing layer. The metal-containing layer 104 includes, but is not limited to, chromium, titanium, gold, silver, copper, aluminum, ITO, combinations thereof, or other suitable conductive materials.

[0025] PS126B is placed on the substrate 102. PS126B may also be placed on the base layer 125. PS126B comprises one of the following: an organic material, an organic material with an inorganic coating placed thereon, or an inorganic material. The organic material of PS126B includes, but is not limited to, polyimide. The inorganic material of PS126B includes, but is not limited to, silicon oxide (SiO2), silicon nitride (Si3N4), silicon oxynitride (Si2N2O), magnesium fluoride (MgF2), or a combination thereof. Adjacent PS126B define their respective subpixels and expose the metal-containing layer 104 of their respective second subpixel circuits 100B.

[0026] The second subpixel circuit 100B has a plurality of subpixel lines (e.g., a first subpixel line 106A and a second subpixel line 106B). These subpixel lines are adjacent to each other along the pixel plane. Each subpixel line contains at least two subpixels. For example, the first subpixel line 106A contains a first subpixel 108A and a second subpixel (not shown), and the second subpixel line 106B contains a third subpixel 108C and a fourth subpixel (not shown). Figure 1A shows the first subpixel line 106A and the second subpixel line 106B, but the second subpixel circuit 100B in the embodiments described herein may contain two or more subpixel lines, such as a third subpixel line and a fourth subpixel. Each subpixel line has an OLED material configured to emit white, red, green, blue, or other colored light when energized. For example, the OLED material in the first subpixel line 106A emits red light when energized, the OLED material in the second subpixel line 106B emits green light when energized, the OLED material in the third subpixel line emits blue light when energized, and the OLED material in the fourth subpixel emits light of a different color when energized. The OLED materials within a single pixel line may be configured to emit light of the same color when energized. For example, the OLED materials in the first subpixel 108A and the second subpixel of the first subpixel line 106A emit red light when energized, and the OLED materials in the third subpixel 108C and the fourth subpixel of the second subpixel line 106B emit green light when energized.

[0027] Each subpixel line includes an adjacent protruding structure 110, and adjacent subpixel lines share the adjacent protruding structure 110. The protruding structures 110 are permanently located in the second subpixel circuit 100B. The protruding structures 110 further define each subpixel line in the second subpixel circuit 100B. Each protruding structure 110 includes adjacent protrusions 117 and 109. The adjacent protrusions 117 and 109 are defined by the first protruding extension portion 117A of the second structure 110B, which extends laterally past the upper surface 105 of the first structure 110A, and the second protruding extension portion 109A of the third structure 110C, which extends laterally past the upper surface 115 of the second structure 110B. The first structure 110A is located on the upper surface 103 of PS126B. The first endpoint 120A of the bottom surface 118 of the first structure 110A may extend to the first edge 127A of PS126B, or it may extend beyond the first edge 127A of PS126B. The second endpoint 120B of the bottom surface of the first structure 110A may extend to the second edge 127B of PS126B, or it may extend beyond the second edge 127B of PS126B.

[0028] The second structure 110B is placed on top of the first structure 110A. The second structure 110B may also be placed on the top surface 105 of the first structure 110A. The second structure 110B may also be placed on top of an intermediate structure. The intermediate structure may also be placed on top surface 105 of the first structure 110A. The intermediate structure may be a seed layer or an adhesive layer. The seed layer functions as a current path for the second subpixel circuit 100B. The seed layer may contain titanium (Ti) material. The adhesion promoting layer improves adhesion between the first structure 110A and the second structure 110B. The adhesive layer may contain chromium (Cr) material. The third structure 110C is placed on top of the second structure 110B. The third structure 110C is placed on top surface 115 of the second structure 110B.

[0029] In one embodiment, the second structure 110B and the third structure 110C include a first structure 110A made of a conductive inorganic material and a non-conductive inorganic material. The conductive materials of the second structure 110B and the third structure 110C include copper (Cu), chromium (Cr), aluminum (Al), aluminum neodymium (AlNd), molybdenum (Mo), molybdenum tungsten (MoW), or a combination thereof. The non-conductive material of the first structure 110A includes amorphous silicon (a-Si), titanium (Ti), silicon nitride (Si3N4), silicon oxide (SiO2), silicon oxynitride (Si2N2O), or a combination thereof. The protruding structure 110 can remain in place; that is, the protruding structure 110 is permanent.

[0030] An adjacent first overhang 117 is defined by a first overhang extension 117A. To form the first overhang extension 117A, at least the bottom surface 107 of the second structure 110B is wider than the top surface 105 of the first structure 110A. The first overhang extension 117A of the second structure 110B forms the first overhang 117, allowing the second structure 110B to shadow the first structure 110A. The shadowing of the first overhang 117 defines the deposition of the OLED material 112 and the cathode 114. The OLED material 112 may include one or more of HIL, HTL, EML, and ETL. The OLED material is placed on and in contact with the metal-containing layer 104. The OLED material 112 is placed below an adjacent first overhang 117. The cathode 114 includes a conductive material such as a metal. For example, the cathode 114 may include, but is not limited to, silver, magnesium, chromium, titanium, aluminum, ITO, or a combination thereof. The cathode 114 is positioned on the OLED material 112, as well as on the side wall 123 of the second structure 110B and the side wall 124 of the third structure 110C of the overhanging structure 110.

[0031] The adjacent second overhang 109 is defined by the second overhang extension 109A of the third structure 110C. To form the second overhang extension 109A of the second overhang 109, at least the bottom surface 121 of the third structure 110C is wider than the top surface 115 of the second structure 110B. The third structure 110C is positioned above the top surface 115 of the second structure 110B. The second overhang extension 109A of the third structure 110C forms the second overhang 109, allowing the third structure 110C to shadow the second structure 110B. The shadowing of the second overhang 109 defines the deposition of the OLED material 112 and the cathode 114, respectively. Each of the OLED material 112 and the cathode 114 is positioned below the second overhang 109. The cathode 114 includes a conductive material such as a metal. For example, the cathode 114 may include, but is not limited to, silver, magnesium, chromium, titanium, aluminum, ITO, or a combination thereof. In one embodiment, the material of the cathode 114 is different from the materials of the first structure 110A, the second structure 110B, and the intermediate structure. In some embodiments, for example, as shown in Figure 1C as applied to a subpixel circuit 100B, the OLED material 112 and cathode 114 are positioned on the side wall 123 of the second structure 110B of the overhanging structure 110 in the pixel plane. In other embodiments, the OLED material 112 and cathode 114 are positioned on the top surface 115 of the second structure 110B of the overhanging structure 110 in the pixel plane. In other embodiments, the OLED material 112 and cathode 114 end on the side wall 111 of the first structure 110A. In other words, the OLED material 112 and the cathode 114 are not positioned on the side wall 123 of the second structure 110B, the side wall 124 of the third structure 110C, or the top surface 122 of the third structure 110C within the pixel plane.

[0032] Each subpixel 106 includes an encapsulation layer 116. The encapsulation layer 116 may be a local passivation layer or equivalent. The encapsulation layer 116 of each subpixel is located on the cathode 114 (and OLED material 112), and the encapsulation layer 116 extends along the respective side walls 111 of the first structure 110A and the second structure 110B, below at least a portion of each of the overhangs 109. The encapsulation layer 116 is located on the cathode 114 and extends in the pixel plane to contact the cathode 114 on the side wall 111 of the first structure 110A, at least. In some embodiments, the encapsulation layer 116 extends to contact the side wall 111 of the first structure 110A. In the illustrated embodiments shown in Figures 1C and 1D, the encapsulation layer 116 extends to contact the second structure 110B at the lower surface and side wall 123 of the first overhanging extension 117A, and contacts the third structure 110C at the lower surface, side wall 124, and upper surface 122 of the second overhanging extension 109A of the third structure 110C. In some embodiments, the encapsulation layer 116 extends to contact the third structure 110C at the lower surface, side wall 124, and upper surface 122 of the second overhanging extension 109A, and is positioned on top of the OLED material 112 and cathode 114 when the OLED material 112 and cathode 114 are in place. In some embodiments, the encapsulation layer 116 terminates at the side wall 111 of the first structure 110A. In other words, the encapsulation layer 116 is not placed on the side wall 123 of the second structure 110B, the side wall 124 of the third structure 110C, the upper surface 122 of the third structure 110C, the lower surface of the first overhang extension 117A, or the lower surface of the second overhang extension 109A. The encapsulation layer 116 contains a non-conductive inorganic material such as a silicon-containing material. This silicon-containing material may contain a material containing Si3N4.

[0033] Each subpixel line may contain adjacent isolation structures, and within the line plane, adjacent subpixels share adjacent isolation structures. The isolation structures are permanently present in the second subpixel circuit 100B. The isolation structures further define each subpixel in the subpixel lines of the second subpixel circuit 100B. The isolation structures are positioned on the upper surface 103 of PS126B.

[0034] The OLED material 112 is positioned in the line plane on top of the metal-containing layer 104 and the isolation structure, in contact with the metal-containing layer 104 and the isolation structure. The cathode 114 is positioned on top of the OLED material 112 in the line plane. The encapsulation layer 116 is positioned on top of the cathode 114 in the line plane. As shown in Figure 1D, the OLED material 112, cathode 114, and encapsulation layer 116 maintain continuity along the length of the line plane to allow current to flow across each subpixel 106.

[0035] In embodiments including one or more capping layers, the capping layers are positioned between the cathode 114 and the encapsulation layer 116. For example, a first capping layer and a second capping layer are positioned between the cathode 114 and the encapsulation layer 116. Each of the embodiments described herein may include one or more capping layers positioned between the cathode 114 and the encapsulation layer 116. The first capping layer may contain an organic material. The second capping layer may contain an inorganic material such as lithium fluoride. The first and second capping layers may be deposited by vapor deposition. In another embodiment, the second subpixel circuit 100B further includes at least one broad-area passivation layer positioned on the protruding structure 110 and the encapsulation layer 116. In yet another embodiment, the subpixel includes an intermediate passivation layer positioned on each of the protruding structures 110 of the subpixel 106 and between the encapsulation layer 116 and the broad-area passivation layer.

[0036] Figure 2 is a schematic cross-sectional view of an overhang structure 210 according to an embodiment. The overhang structure 210 is shown without the accompanying substrate 102, metal-containing layer 104, PS126A / 126B, OLED material 112, cathode 114, or encapsulation layer 116. The overhang structure 210 may be placed on PS126A or PS126B instead of the overhang structure 110.

[0037] Each cantilever structure 210 includes an adjacent first cantilever 217, an adjacent second cantilever 209, and an adjacent third cantilever 222. The adjacent first cantilever 217 is defined by a first cantilever extension 217A of the second structure 210B that extends laterally past the top surface of the first structure 210A. The first structure 210A is positioned on the top surfaces 103 of a plurality of adjacent PS126A or PS126B. The adjacent second cantilever 209 is defined by a second cantilever extension 209A of the third structure 210C that extends laterally past the top surface of the second structure 210B. The third structure 210C is positioned on the second structure 210B.

[0038] The adjacent third overhang 222 is defined by a third extension 222A of the fourth structure 210D. In one embodiment, the fourth structure 210D includes a non-conductive inorganic material. In another embodiment, the fourth structure 210D includes a conductive material. To form the third extension 222A of the third overhang 222, at least the bottom surface of the fourth structure 210D is wider than the top surface of the third structure 210C. The fourth structure 210D is positioned above the top surface of the third structure 210C. The third extension 222A of the fourth structure 210D forms the third overhang 222, allowing the fourth structure 210D to shadow the third structure 210C. The shadowing of the third overhang 222 defines the deposition of the OLED material 112 and the cathode 114, respectively. The OLED material 112 and the cathode 114, respectively, may be positioned below the third overhang 222.

[0039] Figure 3 is a schematic cross-sectional view of an overhang structure 310 according to an embodiment. The overhang structure 310 is shown without the accompanying substrate 102, metal-containing layer 104, PS126A / 126B, OLED material 112, cathode 114, or encapsulation layer 116. The overhang structure 310 may be placed on PS126A or PS126B instead of the overhang structure 110.

[0040] Each overhanging structure 310 includes an adjacent first overhang 317 and an adjacent second overhang 309. The adjacent first overhang 317 is defined by a first overhanging extension portion 317A of the second structure 310B that extends laterally past the top surface of the first structure 310A. The first structure 310A is positioned on the top surfaces 103 of a plurality of adjacent PS126A / 126B. An intermediate structure 323 is positioned on the top surface of the second structure 310B. In one embodiment, the intermediate structure 323 includes a non-conductive inorganic material. In another embodiment, the intermediate structure 323 includes a conductive material. The adjacent second overhang 309 is defined by a second overhanging extension portion 309A of the third structure 310C that extends laterally past the top surface of the second structure 310B.

[0041] The adjacent second overhang 309 is defined by the second overhang extension 309A of the third structure 310C. In order to form the second overhang extension 309A of the second overhang 309, at least the bottom surface of the third structure 310C is wider than the top surface of the second structure 310B, the top surface of the intermediate structure 323, and the bottom surface of the intermediate structure 323. The third structure 310C is positioned above the top surface of the intermediate structure 323. The second overhang extension 309A of the third structure 310C forms the second overhang 309, allowing the third structure 310C to shadow the second structure 310B and the intermediate structure 323.

[0042] Figure 4 is a schematic cross-sectional view of an overhang structure 410 according to an embodiment. The overhang structure 410 is shown without the accompanying substrate 102, metal-containing layer 104, PS126A / 126B, OLED material 112, cathode 114, or encapsulation layer 116. The overhang structure 410 may be placed on PS126A or PS126B instead of the overhang structure 110.

[0043] Each cantilever structure 410 includes an adjacent first cantilever 417 and an adjacent second cantilever 409. The adjacent first cantilever 417 is defined by a first cantilever extension 417A of the second structure 410B that extends laterally past the upper surface of the first structure 410A. The first structure 410A is positioned on the upper surfaces 103 of a plurality of adjacent PS126A / 126B.

[0044] The adjacent second overhang 409 is defined by the side wall 413 of the third structure 410C. In order to form the side wall 413 of the second overhang 409, at least the upper surface of the third structure 410C is wider than the bottom surface of the third structure 410C. The side wall 413 of the third structure 410C forms the second overhang 409.

[0045] Figure 5 is a schematic cross-sectional view of an overhang structure 510 according to an embodiment. The overhang structure 510 is shown without the accompanying substrate 102, metal-containing layer 104, PS126A / 126B, OLED material 112, cathode 114, or encapsulation layer 116. The overhang structure 510 may be placed on PS126A or PS126B instead of the overhang structure 110.

[0046] Each cantilever structure 510 includes an adjacent first cantilever 517, an adjacent second cantilever 509, and an adjacent third cantilever 522. The adjacent first cantilever 517 is defined by a first cantilever extension 517A of the second structure 510B that extends laterally past the upper surface of the first structure 510A. The first structure 510A is positioned on the upper surfaces 103 of a plurality of adjacent PS126A / 126B.

[0047] The adjacent second overhang 509 is defined by the side wall 513 of the third structure 510C. In order to form the side wall 513 of the second overhang 509, at least the upper surface of the third structure 510C is wider than the bottom surface of the third structure 510C. The side wall 513 of the third structure 510C forms the second overhang 509.

[0048] The adjacent third overhang 522 is defined by the side wall 515 of the fourth structure 510D. In order to form the side wall 515 of the third overhang 522, at least the bottom surface of the fourth structure 510D is wider than the bottom surface of the fourth structure 510D. The fourth structure 510D is positioned on the top surface of the third structure 510C. The side wall 515 of the fourth structure 510D forms the third overhang 522.

[0049] Figure 6 is a schematic cross-sectional view of an overhang structure 610 according to an embodiment. The overhang structure 610 is shown without the accompanying substrate 102, metal-containing layer 104, PS126A / 126B, OLED material 112, cathode 114, or encapsulation layer 116. The overhang structure 610 may be placed on PS126A or PS126B instead of the overhang structure 110.

[0050] Each overhanging structure 610 includes an adjacent first overhanging structure 617 and an adjacent second overhanging structure 609. The adjacent first overhanging structure 617 is defined by a first overhanging extension portion 617A of the second structure 610B that extends laterally past the upper surface 103 of the first structure 610A. The first structure 610A is positioned on the upper surfaces 103 of a plurality of adjacent PS126A / 126B.

[0051] The second structure 610B includes a lower side wall 623 and an upper side wall 624. The adjacent second overhang 609 is defined by the upper side wall 624 of the second structure 610B. The top surface 615 of the second structure 610B may be wider than the bottom surface 607 of the second structure 610B, or it may be equal to the bottom surface 607 of the second structure 610B (as shown in the illustrated embodiment), or it may be narrower than the bottom surface 607 of the second structure 610B. The second structure 610B further includes an internal plane 625. The widths of the top surface 615 and the bottom surface 607 of the second structure 610B are wider than the width of the second structure 610B in the internal plane 625. The lower side wall 623 is formed between the bottom surface 607 of the second structure 610B and the internal plane 625. The upper side wall 624 is formed between the upper surface 615 and the internal plane 625 of the second structure 610B. The upper side wall 613 of the second structure 610B forms a second overhang 609, allowing the upper side wall 613 to shadow the side wall 623.

[0052] The encapsulation layer 116 is positioned beneath the adjacent overhangs of the overhang structures 110, 210, 310, 410, 510, and 610. Thus, the adjacent overhangs provide protection against moisture intrusion into the overhang structures 110, 210, 310, 410, 510, and 610. Due to the contact between the encapsulation layer 116 and the overhang structures 110, 210, 310, 410, 510, and 610, the adjacent overhangs form more complex moisture intrusion pathways. When moisture intrudes into the overhang structures 110, 210, 310, 410, 510, and 610, the encapsulation layer 116 forms a barrier between the moisture and the overhang structures 110, 210, 310, 410, 510, and 610.

[0053] Figure 7 is a flowchart of method 700 for forming a first subpixel circuit 100A or a second subpixel circuit 100B. Figures 8A to 8D are schematic cross-sectional views of the substrate 102 during method 700 for forming a first subpixel circuit 100A or a second subpixel circuit 100B.

[0054] In operation 701, the first structural layer 802A and the second structural layer 802B are deposited on the substrate 102 as shown in Figure 8A. The first structural layer 802A is placed on PS126A or PS126B. The second structural layer 802B is placed on top of the first structural layer 802A. The first structural layer 802A corresponds to the first structures 110A, 210A, 310A, 410A, 510A, and 610A of the overhang structures 110, 210, 310, 410, 510, and 610, respectively. The second structural layer 802B corresponds to the second structures 110B, 210B, 310B, 410B, 510B, and 610B of the overhang structures 110, 210, 310, 410, 510, and 610. The second structural layer 802B may also correspond to the third structures 110C, 210C, 310C, 410C, and 510C, the intermediate structure 323, and the fourth structures 210D and 510D. The resist 806 is placed and patterned. The resist 806 is placed on top of the second structural layer 802B. The resist 806 is either a positive resist or a negative resist. A positive resist contains portions of the resist that, when exposed to electromagnetic radiation, are soluble to the resist developer applied to the resist after the pattern has been written to the resist using that electromagnetic radiation. A negative resist contains portions of the resist that, when exposed to electromagnetic radiation, are insoluble to the resist developer applied to the resist after the pattern has been written to the resist using that electromagnetic radiation. The chemical composition of the resist 306 determines whether the resist is a positive resist or a negative resist.

[0055] In operation 702, the portion of the second structural layer 802B exposed by the resist 806 is removed, as shown in Figure 8B. The second structural layer 802B exposed by the resist 806 may be removed by a dry etching process. In the illustrated embodiment, operation 702 forms the second structure 110B and the third structure 110C. In other embodiments, operation 702 may form the second structures 210B, 310B, 410B, 510B, and 610B, the third structures 210C, 310C, 410C, and 510C, the intermediate structure 323, and the fourth structures 210D and 510D.

[0056] In operation 703, the portion of the first structural layer 802A exposed by the resist 806 is removed, as shown in Figure 8C. The first structural layer 802A exposed by the resist 806 may be removed by a wet etching process. In the illustrated embodiment, operation 703 forms the first structure 110A of the protruding structure 110. In other embodiments, operation 703 forms the first structures 210A, 310A, 410A, 510A, and 610A of the protruding structures 110, 210, 310, 410, 510, and 610, respectively. The etching selectivity between materials of the second structural layer 802B corresponding to the second structure 110B and the third structure 110C, the first structural layer 802A corresponding to the first structure 110A, and the etching process for removing exposed portions of the second structural layer 802B and the first structural layer 802A define the bottom surface 107 of the second structure 110B, which is wider than the top surface 105 of the first structure 110A, in order to form the first overhang extension portion 117A of the first overhang 117.

[0057] In operation 704, the resist 806 is removed from the third structure 110C, as shown in Figure 8D, leaving the protruding structure 110.

[0058] In operation 705, the OLED material 112, cathode 114, and encapsulation layer 116 of the first subpixel 108A are deposited. Shadowing of the first overhang 117 and the second overhang 109 defines the deposition of the OLED material 112 and cathode 114, respectively.

[0059] In summary, embodiments described herein relate to a subpixel circuit that may be used in a display such as an organic light-emitting diode (OLED) display, and a method for forming a subpixel circuit. A plurality of adjacent pixels (PS) are arranged on a substrate. Each subpixel includes an adjacent first protrusion, each first protrusion defined by a first protrusion extension of a second structure that extends laterally past the top surface of the first structure. The first structure is arranged on the PS, while the second structure is arranged on top of the first structure. An adjacent second protrusion is defined by a second protrusion extension of a third structure that extends laterally past the top surface of the second structure. The third structure is arranged on top of the second structure. To improve the functionality of the subpixel circuit, an encapsulation layer is provided within the adjacent second protrusion, which provides protection against moisture ingress into the adjacent first protrusion.

[0060] While the above description applies to embodiments of the present disclosure, other embodiments and additional embodiments of the present disclosure may be devised without departing from the basic scope of the present disclosure, and the scope of the present disclosure is determined by the following claims.

Claims

1. circuit board and A plurality of protruding structures are arranged on the substrate, and each protruding structure is The first structure and A second structure is placed on the upper surface of the first structure, An adjacent first projection, each first projection defined by an extension of the first projection of the second structure that extends laterally past the upper surface of the first structure, A third structure placed on top of the second structure, The adjacent second extension and Multiple protruding structures having, It consists of multiple subpixels, and each subpixel is A-scatter, An organic light-emitting diode (OLED) material disposed on the anode, A cathode placed on the OLED material and Multiple subpixels and A device equipped with the following features.

2. The device according to claim 1, wherein the adjacent second protrusion is defined by a second protrusion extension of the third structure that extends laterally past the upper surface of the second structure, and the third structure is positioned on the upper surface of the second structure.

3. The third structure described above is The bottom and, The top surface is wider than the bottom surface, A side wall formed between the bottom surface and the top surface, wherein the adjacent second protrusion is defined by the side wall and The device according to claim 1, further comprising:

4. The third structure further comprises a fourth structure disposed on the upper surface thereof, wherein the fourth structure is The bottom and, The top surface is wider than the bottom surface, A side wall formed between the bottom surface and the top surface, and an adjacent third protrusion defined by the side wall. The device according to claim 3, comprising:

5. An adjacent third projection, each third projection defined by a third extension of a fourth structure that extends laterally past the upper surface of the third structure, wherein the fourth structure is positioned on the upper surface of the third structure. The device according to claim 1, further comprising:

6. The device according to claim 1, further comprising an intermediate structure disposed on the second structure, wherein the third structure is disposed on the intermediate structure.

7. The third structure further comprises a fourth structure disposed on the upper surface thereof, wherein the fourth structure is The bottom and, The top surface is wider than the bottom surface, A side wall formed between the bottom surface and the top surface, and an adjacent third protrusion defined by the side wall. The device according to claim 1, comprising:

8. The device according to claim 1, further comprising a pixel structure (PS) disposed on the substrate, wherein the protruding structure is disposed on the PS.

9. The aforementioned PS is polyimide, silicon dioxide (SiO 2 ), silicon nitride (Si 3 N 4 ), silicon oxynitride (Si 2 N 2 O), magnesium fluoride (MgF 2 The device according to claim 7, which includes, or a combination thereof.

10. The device according to claim 1, further comprising a pixel structure (PS) disposed on the substrate, wherein the protruding structure is disposed on the PS.

11. The PS includes polyimide, silicon oxide (SiO 2 ), silicon nitride (Si 3 N 4 ), silicon oxynitride (Si 2 N 2 O), magnesium fluoride (MgF 2 ), or a combination thereof, the device according to claim 9.

12. circuit board and A plurality of protruding structures are arranged on the substrate, and each protruding structure is The first structure and A second structure is disposed on the upper surface of the first structure, and the second structure is Internal plane and, Top surface and, An upper side wall formed between the aforementioned internal plane and the aforementioned upper surface, The bottom and, A lower side wall formed between the internal plane and the bottom surface A second structure comprising, An adjacent first projection, each first projection defined by an extension of the first projection of the second structure that extends laterally past the upper surface of the first structure, The adjacent second protrusion formed by the aforementioned upper side wall Multiple cantilevered structures, It consists of multiple subpixels, and each subpixel is A-scatter, An organic light-emitting diode (OLED) material disposed on the anode, A cathode placed on the OLED material and Multiple subpixels and A device equipped with the following features.

13. The device according to claim 12, wherein the width of the upper side wall is wider than the width of the second structure in the internal plane.

14. The device according to claim 12, further comprising a pixel structure (PS) disposed on the substrate, wherein the protruding structure is disposed on the PS.

15. The aforementioned pixel structure (PS) is made of polyimide, silicon dioxide (SiO 2 ), silicon nitride (Si 3 N 4 ), silicon oxynitride (Si 2 N 2 O), magnesium fluoride (MgF 2 The device according to claim 14, which includes, or a combination thereof.

16. The device according to claim 12, further comprising a pixel structure (PS) disposed on the substrate, wherein the protruding structure is disposed on the PS.

17. The aforementioned PS is polyimide, silicon dioxide (SiO 2 ), silicon nitride (Si 3 N 4 ), silicon oxynitride (Si 2 N 2 O), magnesium fluoride (MgF 2 The device according to claim 15, which includes, or a combination thereof.

18. The process involves depositing a first structural layer and a second structural layer on a substrate, The portion exposed by the resist of the second structural layer is removed to form the second and third structures, The first structure is formed by removing the portion of the first structural layer exposed by the resist, Removing the resist from the third structure, The process involves depositing organic light-emitting diode (OLED) material, a cathode, and an encapsulation layer. Methods that include...

19. The method according to claim 18, wherein the portion of the second structural layer is removed by a dry etching process.

20. The method according to claim 18, wherein the portion of the first structural layer is removed by a wet etching process.

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