Adhesion promoting layer for preventing delamination of oh top / body from anode surface

Abstract

Embodiments described herein generally relate to displays. More specifically, embodiments described herein relate to sub-pixel circuits that can be utilized in displays, such as organic light emitting diode (OLED) displays, and methods of forming sub-pixel circuits. In one embodiment, a sub-pixel circuit is provided. The sub-pixel circuit includes a substrate, a plurality of sub-pixels, and a cathode ring disposed about a perimeter of the sub-pixel circuit. Each sub-pixel of the plurality of sub-pixels includes a plurality of overhanging structures disposed above the substrate, the overhanging structures including a first structure, a second structure, and an extension disposed through a sidewall of the first structure, a metal structure disposed above the substrate, an adhesion layer disposed under the first structure of the plurality of overhanging structures, an overhang gap fill structure, an organic OLED material disposed above the metal structure, and a cathode disposed above the OLED material.

Description

Background Technology

[0001] field

[0002] The embodiments described herein generally relate to displays. More specifically, the embodiments described herein relate to sub-pixel circuits that can be used in displays (such as organic light-emitting diode (OLED) displays) and methods for forming sub-pixel circuits.

[0003] Related technical descriptions

[0004] Input devices, including display devices, are used in a wide variety of electronic systems. An organic light-emitting diode (OLED) is a type of light-emitting diode (LED) in which the emitting electroluminescent layer is a film of organic compounds that emits light in response to an electric current. OLED devices are classified as bottom-emitting devices if the emitted light passes through a transparent or translucent bottom electrode and the substrate on which the panel is manufactured. Top-emitting devices are classified based on whether the light emitted from the OLED device passes through a cover added after the device is manufactured. Many electronic products today use OLEDs to manufacture display devices. Today's electronics manufacturers are pushing these display devices to shrink in size while offering higher resolutions than they did a few years ago.

[0005] OLED pixel patterning currently relies on processes that limit panel size, pixel resolution, and substrate size. Instead of using fine metal masks, optical lithography could be used to pattern pixels. Currently, OLED pixel patterning requires the removal of organic materials after the patterning process. When these organic materials are removed, particle issues remain, affecting OLED performance. Therefore, what is needed in this field is improved sub-pixel circuitry and methods for forming such circuitry. Summary of the Invention

[0006] The embodiments described herein generally relate to displays. More specifically, the embodiments described herein relate to sub-pixel circuits that can be used in displays (such as organic light-emitting diode (OLED) displays) and methods for forming sub-pixel circuits.

[0007] In one embodiment, a sub-pixel circuit is provided. The sub-pixel circuit includes a substrate, a plurality of metal structures disposed above the substrate, a gap-filling structure, and a suspended structure. The suspended structure includes an extension disposed through a sidewall of the suspended structure, an adhesive layer disposed above each gap-filling structure, an organic light-emitting diode (OLED) material disposed above the metal structures, a cathode disposed above the OLED material, and a cathode ring disposed above the substrate.

[0008] In another embodiment, a sub-pixel circuit is provided. The sub-pixel circuit includes a substrate, a plurality of sub-pixels, and a cathode ring disposed around the periphery of the sub-pixel circuit. Each of the plurality of sub-pixels includes a plurality of suspended structures disposed above the substrate. The suspended structure includes a first structure, a second structure, and an extension disposed through the sidewall of the first structure, a metal structure disposed above the substrate, an adhesive layer disposed below the first structure of the plurality of suspended structures, a gap-filling structure for the suspended structures, an organic light-emitting diode (OLED) material disposed above the metal structure, and a cathode disposed above the OLED material.

[0009] In another embodiment, a method is provided. The method includes: depositing an adhesive material over a substrate, the substrate including a plurality of metal structures, a plurality of cantilever gap-filling structures, and a cathode ring; removing a portion of the adhesive material such that an adhesive layer is at least partially disposed over the plurality of cantilever gap-filling structures; forming a cantilever structure over the adhesive layer over the plurality of cantilever gap-filling structures, the cantilever structure including an extension disposed through a sidewall of the cantilever structure; depositing an organic light-emitting diode (OLED) material over the substrate, the OLED material being disposed over the metal structures; and depositing a cathode, wherein the cathode is disposed below each extension of the cantilever structure. Brief description of the attached figures

[0010] To gain a more detailed understanding of the features described above in this disclosure, reference can be made to some embodiments shown in the accompanying drawings for a more specific description of the disclosure, which has been briefly outlined above. However, it should be noted that the drawings illustrate only exemplary embodiments and should not be considered as limiting its scope, and other equivalent embodiments are permissible.

[0011] Figure 1A This is a schematic cross-sectional view of the sub-pixel circuit along the pixel line at section line 1A-1A according to the embodiment.

[0012] Figure 1B This is a schematic cross-sectional view of the sub-pixel circuit along the line plane at section line 1B-1B according to the embodiment.

[0013] Figure 2 This is a schematic top view of the sub-pixel circuit according to the embodiment.

[0014] Figure 3 This is a flowchart of a method for forming a sub-pixel circuit according to one or more embodiments.

[0015] Figures 4A-4E It is based on one or more embodiments in Figure 3 A schematic cross-sectional view of the substrate during the method for forming sub-pixel circuits.

[0016] For ease of understanding, the same reference numerals are used where possible to indicate common elements in the drawings. It is contemplated that elements disclosed in one embodiment may be advantageously used in other embodiments without specific description. Detailed Implementation

[0017] The embodiments described herein generally relate to displays. More specifically, the embodiments described herein relate to sub-pixel circuits that can be used in displays, such as organic light-emitting diode (OLED) displays, and methods of forming sub-pixel circuits. The sub-pixel circuit includes an adhesive layer. The adhesive layer facilitates adhesion between the suspended structure and at least the suspended space-filling structure.

[0018] Each sub-pixel circuit includes at least one sub-pixel. The sub-pixel includes a substrate, a metal structure (e.g., an anode), a suspended structure, a suspended space gap-filling structure, a separation gap-filling structure, an organic light-emitting diode (OLED) material, an adhesive layer, and a cathode. The metal structure is defined by adjacent first suspended structures and adjacent second suspended structures. The suspended structures are disposed above the suspended space gap-filling structures. The suspended structures include a second structure disposed above the first structure. The bottom surface of the second structure extends laterally through the upper surface of the first structure to form an extension. The OLED material is disposed above the anode. The cathode is disposed above the OLED material. The adhesive layer is deposited above the suspended space gap fill. The suspended space gap-filling structures are located between adjacent anodes. The sub-pixel circuit includes a cathode ring. Figure 2 As shown, the cathode ring surrounds the perimeter of the sub-pixel circuit. In one or more embodiments, the second structure of the suspended structure extends at least partially above the cathode ring.

[0019] Each embodiment of the subpixel circuit described herein includes a plurality of subpixels. Each subpixel is defined by an adjacent cantilever structure, which is permanent to the subpixel circuit. Although two subpixels are depicted in the figures, each defined by an adjacent cantilever structure, the subpixel circuit of the embodiments described herein includes a plurality of subpixels, such as two or more subpixels. Each subpixel includes an OLED material configured to emit white, red, green, blue, or other colors of light when activated. For example, the OLED material of the first subpixel emits red light when activated, the OLED material of the second subpixel emits green light when activated, and the OLED material of the third subpixel emits blue light when activated.

[0020] The suspended structure is permanent to the sub-pixel circuitry and includes at least a second structure disposed on the first structure. Adjacent suspended structures defining the sub-pixel circuitry of the display are formed using evaporation deposition to form the sub-pixel circuitry and to hold the suspended structure in place after the sub-pixel circuitry is formed. Evaporation deposition is used to deposit OLED materials (including a hole injection layer (HIL), a hole transport layer (HTL), an emitter layer (EML), and an electron transport layer (ETL)) and a cathode. In some cases, an encapsulation layer may be disposed by evaporation deposition. In embodiments including one or more capping layers, the capping layer is disposed between the cathode and the encapsulation layer. The suspended structure and the evaporation angle set by the evaporation source define the deposition angle; for example, the suspended structure may provide a shading effect at the evaporation angle set by the evaporation source during evaporation deposition. To deposit at a specific angle, the evaporation source is configured to emit deposited material at a specific angle relative to the suspended structure. The encapsulation layer of the individual sub-pixel is disposed above the cathode, below at least a portion of each of the adjacent suspended structures, and extends along the sidewalls of each of the adjacent suspended structures.

[0021] Figure 1A This is a schematic cross-sectional view of the sub-pixel circuit 100 along the pixel plane 100A. Figure 1A The cross-sectional view is along Figure 2 The cross-section is taken along line 1A-1A. Pixel plane 100A corresponds to the X direction. Figure 1C is a schematic cross-sectional view of the sub-pixel circuit 100 along line plane 100B. The cross-sectional view of 1B is along... Figure 2 The section line 1B-1B is used for cutting. The plane 100B corresponds to the Y direction. Figure 1A The first sub-pixel 106A and the second sub-pixel 106B are displayed. The sub-pixel circuit 100 includes a substrate 102, a metal structure 104, a gap filling structure (e.g., a suspended gap filling structure 126 or a separate gap filling structure 125), a cathode ring 120, a suspended structure 110, an adhesive layer 180, an OLED material 112, a cathode 114, and an encapsulation layer 116.

[0022] Subpixel circuit 100 includes substrate 102. In one or more embodiments, substrate 102 is a backplane. The backplane includes (but is not limited to) a complementary metal-oxide-semiconductor (CMOS) array, a thin-film transistor (TFT) array, or a glass backplane. In one or more embodiments, a metal structure 104 is pre-patterned on substrate 102. For example, the substrate is pre-patterned with a metal structure 104 (e.g., an anode) comprising a metal-containing material. Metal-containing materials include indium tin oxide (ITO), chromium, chromium oxide (Cr2O3), titanium, gold, silver, copper, aluminum, transparent conductive oxide (TCO), combinations thereof, or other suitable conductive materials. The metal structure 104 is configured as the anode of an individual subpixel. In one embodiment, the metal structure 104 is a stack of layers comprising 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.

[0023] A cathode ring 120 surrounds the perimeter of the sub-pixel circuit 100. For example... Figure 1A and 1B As shown, the cathode ring 120 includes at least one layer. The at least one layer includes a metallic material. The metallic material includes (but is not limited to) a transparent conductive oxide (TCO) material, tin oxide (IV) (SnO2), aluminum (Al), titanium nitride (TiN), or combinations thereof. The TCO may be indium tin oxide (ITO). In some embodiments, the cathode ring 120 includes a layer stack. The layer stack includes at least three layers. For example, the layer stack includes a first transparent conductive oxide (TCO) layer, a second metallic layer disposed on the first TCO layer, and a third TCO layer disposed on the second metallic layer. For example, the cathode ring 120 includes an Al layer, a TiN layer, and a SnO2 layer. In this example, the Al layer has a thickness of about 200 nm to about 300 nm, the TiN layer has a thickness of less than 10 nm, and the SnO2 layer is less than 20 nm. At least one of the metallic material or the layers of the layer stack of the single-layer cathode ring 120 may include the same material as the metal structure 104 (e.g., the cathode ring 120 and the metal structure 104 include the same metallic material and / or the same layer stack). The cathode ring 120 contacts at least one gap-filling structure. For example, such as Figure 1A As shown, the cathode ring 120 contacts at least one of the suspension gap filling structures 126. For example, as... Figure 1B As shown, the cathode ring 120 contacts at least one of the separation gap filling structures 125.

[0024] like Figure 1AAs shown, one or more overhanging gap-filling structures 126 are disposed above substrate 102. The overhanging gap-filling structure 126 comprises an organic material, an organic material with an inorganic coating disposed thereon, or an inorganic material. The organic material of the overhanging gap-filling structure 126 includes (but is not limited to) polyimide. The inorganic material of the overhanging gap-filling structure 126 includes (but is not limited to) silicon oxide (SiO2), silicon nitride (Si3N4), silicon oxynitride (Si2N2O), magnesium fluoride (MgF2), or combinations thereof. An adhesive layer 180 is disposed above each overhanging gap-filling structure 126 to facilitate adhesion between the first structure 110A of each overhanging structure 110 and the overhanging gap-filling structure 126. In one or more embodiments, the adhesive layer 180 facilitates adhesion between the first structure 110A of the overhanging structure 110 and the metal structure 104 or substrate 102. The adhesive layer 180 is any TCO, oxide-containing layer, or silicon-containing layer. The silicon-containing layer may include a silicon nitride (SiNx) layer. The oxide layer may include tin oxide (SnO2). The TCO layer may include indium gallium zinc oxide (IGZO), indium zinc oxide (IZO), ITO, or any similar material.

[0025] like Figure 1B As shown, the sub-pixel circuit 100 includes a separation gap filling structure 125. Each sub-pixel line (e.g., as shown) Figure 2 The first sub-pixel line 108A or the second sub-pixel line 108B shown includes a gap fill structure 125, which is shared by adjacent sub-pixels. The gap fill structure 125 is permanent to the sub-pixel circuit 100. The gap fill structure 125 further defines each sub-pixel of the first sub-pixel line 108A of the sub-pixel circuit 100 (e.g., first sub-pixel 106A and third sub-pixel 106C). The gap fill structure 125 may also be referred to as gap fill between adjacent anodes. In one or more embodiments, an aluminum oxide layer 122 is disposed above the gap fill structure 125.

[0026] Sub-pixel circuit 100 has multiple sub-pixel lines (e.g., Figure 2 The first sub-pixel line 108A or the second sub-pixel line 108B in the pixel plane 100A. The sub-pixel lines (e.g., the first sub-pixel line 108A and the second sub-pixel line 108B) are adjacent to each other along the pixel plane 100A. Although Figure 1AThe first subpixel line 108A and the second subpixel line 108B are depicted, but the subpixel circuit 100 in the embodiments described herein may include two or more subpixel lines, such as a third subpixel line and a fourth subpixel line. Each subpixel line includes OLED material 112 configured to emit white, red, green, blue, or other colors of light when energized. In some embodiments, the OLED material 112 within the pixel line (e.g., the first subpixel line 108A and the second subpixel line) is configured to emit the same color of light when energized. In other embodiments, the OLED material 112 within the pixel line (e.g., the first subpixel line 108A and the second subpixel line 108B) is configured to emit different colors of light when energized. For example, the OLED material 112 of the first sub-pixel line 108A emits red light when activated, the OLED material of the second sub-pixel line 108B emits green light when activated, the OLED material of the third sub-pixel line emits blue light (not shown) when activated, and the OLED material of the fourth sub-pixel (not shown) emits a different color of light when activated. For example, the OLED material of the first sub-pixel 106A emits red light when activated, and the OLED material of the second sub-pixel 106B emits green light when activated.

[0027] Each subpixel line includes a cantilever structure 110, and adjacent subpixel lines share the cantilever structure 110 in the pixel plane. The cantilever structure 110 is permanent to the subpixel circuit 100. The cantilever structure 110 further defines each subpixel line of the subpixel circuit 100. Each cantilever structure 110 includes an adjacent cantilever portion 109. The adjacent cantilever portion 109 is defined by a cantilever extension 109A of a second structure 110B that extends laterally through the upper surface 105 of the first structure 110A. In one or more embodiments, the first structure 110A contacts an adhesive layer 180. The adhesive layer 180 facilitates adhesion between the first structure 110A and the cantilever gap-filling structure 126. In one or more embodiments, at least a portion of the cantilever extension 109A extends over the cathode ring 120.

[0028] The first structure 110A comprises a non-conductive or conductive material. The second structure 110B comprises a non-conductive or conductive material. In some embodiments, the first structure 110A and the second structure 110B comprise the same material. In other embodiments, the first structure 110A and the second structure 110B comprise different materials. The non-conductive material comprises a titanium-containing material or a silicon-containing material. The silicon-containing material comprises (but is not limited to) amorphous silicon (a-Si), silicon nitride (Si3N4), silicon oxide (SiO2), silicon oxynitride (Si2N2O), or combinations thereof. The conductive material comprises (but is not limited to) aluminum (Al), aluminum neodymium (AlNd), molybdenum (Mo), molybdenum-tungsten (MoW), copper (Cu), or combinations thereof.

[0029] The suspended extension 109A of the second structure 110B forms an adjacent suspended portion 109 and allows the second structure 110B to shield the first structure 110A. The shadow of the adjacent suspended portion 109 provides for the evaporation deposition of the OLED material 112 and the cathode 114. The OLED material 112 may include one or more of a hole injection layer (HIL), a hole transport layer (HTL), an emitter layer (EML), an electron injection layer (EIL), and an electron transport layer (ETL). The OLED material 112 is disposed above and in contact with the metal structure 104. The OLED material 112 is disposed below the adjacent suspended portion 109 and may contact the sidewall 111 of the first structure 110A. In one embodiment, the OLED material 112 is different from the materials of the first structure 110A, the second structure 110B, and the suspended gap filling structure 126. The cathode 114 is disposed above the OLED material 112 and extends below the adjacent suspended portion 109. The cathode 114 extends through the endpoints of the OLED material 112.

[0030] The cathode 114 comprises a conductive material, such as a metal. For example, the cathode 114 comprises (but is not limited to) silver, magnesium, chromium, titanium, aluminum, ITO, or combinations thereof. In one embodiment, the material of the cathode 114 differs from the materials of the first structure 110A and the second structure 110B. In one or more embodiments, the OLED material 112 and the cathode 114 do not contact the sidewall 111 of the first structure 110A. In one or more embodiments, the OLED material 112 contacts the sidewall 111 of the first structure 110A.

[0031] Each sub-pixel (e.g., first sub-pixel 106A and second sub-pixel 106B) includes an encapsulation layer 116. The encapsulation layer 116 may be or correspond to a local passivation layer. The encapsulation layer 116 of each individual sub-pixel is disposed above the cathode 114 (and OLED material 112), and extends below at least a portion of each of the overhanging extensions 109A and along the sidewalls 111 of each of the first structure 110A and the second structure 110B. The encapsulation layer 116 is disposed above the cathode 114 and extends through the cathode 114, between the cathode and the sidewalls 111, and at least partially above the sidewalls 111. In some embodiments, the encapsulation layer 116 extends to contact the sidewalls 111 of the first structure 110A. Figure 1AIn the illustrated embodiment, the encapsulation layer 116 extends to contact the second structure 110B at the bottom surface of the suspended extension 109A, the sidewall 113 of the second structure 110B, and the upper surface 115 of the second structure 110B. In some embodiments, the encapsulation layer 116 extends to contact the second structure 110B at the bottom surface of the suspended extension 109A and is disposed above the adhesive layer 180, the OLED material 112, and the cathode 114. In other embodiments, the encapsulation layer 116 terminates at the sidewall 111 of the first structure 110A (e.g., not disposed above the sidewall 113 of the second structure 110B, the upper surface 115 of the second structure 110B, or the bottom surface of the suspended extension 109A of the suspended structure 110). The encapsulation layer 116 comprises a non-conductive inorganic material, such as a silicon-containing material. The silicon-containing material may include a Si3N4-containing material.

[0032] In embodiments including one or more capping layers, the capping layers are disposed between the cathode 114 and the encapsulation layer 116. For example, a first capping layer and a second capping layer are disposed between the cathode 114 and the encapsulation layer 116. Each of the embodiments described herein may include one or more capping layers disposed between the cathode 114 and the encapsulation layer 116. The first capping layer may include an organic material. The second capping layer may include an inorganic material, such as lithium fluoride. The first and second capping layers may be deposited by evaporation deposition. In another embodiment, the sub-pixel circuit 100 further includes at least one global passivation layer disposed over the suspended structure 110 and the encapsulation layer 116. In yet another embodiment, the sub-pixel includes an intermediate passivation layer disposed over the suspended structure 110 of each of the sub-pixels (e.g., the first sub-pixel 106A and the second sub-pixel 106B) and disposed between the encapsulation layer 116 and the global passivation layer.

[0033] Figure 2This is a schematic top view of a sub-pixel circuit 100 having architecture 200 according to an embodiment. Architecture 200 includes a plurality of pixel openings 124. Each of the pixel openings 124 is adjacent to a cantilever structure 110 and a gap fill structure 125, which define each of the sub-pixel lines (e.g., first sub-pixel line 108A and second sub-pixel line 108B) and sub-pixels (e.g., first sub-pixel 106A and second sub-pixel 106B) of architecture 200. Evaporation deposition is used for the deposition of OLED materials (including a hole injection layer (HIL), a hole transport layer (HTL), an emitter layer (EML), and an electron transport layer (ETL)). Evaporation deposition is also used for the deposition of inorganic materials and cathode materials. In some cases, an encapsulation layer may be provided by evaporation deposition. In embodiments including one or more capping layers, the capping layer is disposed between the cathode and the encapsulation layer. The suspended structure and the evaporation angle set by the evaporation source define the deposition angle; for example, the suspended structure can provide a shadow effect at the evaporation angle set by the evaporation source during evaporation deposition. To deposit at a specific angle, the evaporation source is configured to emit deposited material at a specific angle relative to the suspended structure. An encapsulation layer for each individual sub-pixel is disposed above the cathode, and the encapsulation layer is below at least a portion of each of the adjacent suspended structures and extends along the sidewalls of each of the adjacent suspended structures.

[0034] A cathode ring 120 surrounds the perimeter of the sub-pixel circuit 100 of the architecture 200. For example... Figure 2 As shown, the cathode ring 120 is rectangular. However, it is contemplated that the cathode ring 120 can be of any shape, such that it surrounds the perimeter of the sub-pixel circuit 100. In one or more embodiments, the overhanging extension 109A of the second structure 110B extends at least partially above the cathode ring 120, as shown in portion 202 of the second structure 110B.

[0035] Figure 3 This is a flowchart of a method 300 for forming a sub-pixel circuit 100. Method 300 forms a sub-pixel circuit 100 having an adhesive layer 180 disposed above a cantilever gap filling structure 126. Figures 4A-4E This is a schematic cross-sectional view of the substrate 102 during the method 300 for forming the sub-pixel circuit 100.

[0036] At operation 302, such as Figure 4AAs shown, a metal structure 104 (e.g., an anode) and a cathode ring 120 are formed over a substrate. This is accomplished by depositing a metal material layer over the substrate 102, followed by depositing a photoresist pattern over the metal material layer. The metal material layer (not protected by the photoresist pattern) is then etched away to form the desired pattern of the metal structure 104 (e.g., an anode structure). The cathode ring 120 is formed by depositing a cathode material layer over the substrate 102, followed by depositing a photoresist pattern over the cathode material layer. The metal material layer (not protected by the photoresist pattern) is then etched away to form the desired pattern of the cathode ring 120. For example, as... Figure 2 As shown, the cathode ring 120 is a rectangle surrounding the sub-pixel circuit 100. In one or more embodiments, the metal structure 104 and the cathode ring 120 are formed of the same material, such that the metal structure 104 and the cathode ring 120 are formed simultaneously. For example, a metal material is deposited over a substrate 102. Photoresist is deposited in a pattern over the metal material, and the unprotected material is etched. The photoresist-protected material forms the metal structure 104 and the cathode ring 120. In one or more embodiments, the metal structure 104 and the cathode ring 120 comprise multiple layers. The layers may comprise different materials or the same material. In embodiments comprising multiple layers, the processes of material deposition, photoresist deposition, and etching may be repeated. Alternatively or additionally, the processes of depositing the metal structure 104 and the cathode ring 120 are repeated, and photoresist deposition and etching processes occur to form the pattern of the metal structure 104 and the cathode ring 120. In one or more embodiments, the metal structure 104 and the cathode ring 120 comprise the same height, which may be done during an etching process or additional planarization process. Alternatively or concurrently, the metal structure 104 and the cathode ring 120 may have different heights.

[0037] At operation 304, such as Figure 4B and 4C As shown (along) Figure 2 The pixel plane 100A and cross-sectional lines 1A-1A shown form a gap-filling structure. Gap-filling material 402 is deposited over the metal structure 104, the cathode ring 120, and the substrate 102. (As shown...) Figure 4C As shown, the gap-filling material 402 is then etched away to form a suspended gap-filling structure 126 between the metal structure 104 and the cathode ring 120. Figure 4C As shown, the suspended space gap filling structure 126 is then planarized such that the top surface of each suspended space gap filling structure 126 is aligned with each other and with the upper surface of the metal structure 104 (e.g., the suspended space gap filling structure 126 and the metal structure 104 have the same height). Alternatively or additionally, the cathode ring 120 is planarized such that the top surface of each suspended space gap filling structure 126, each metal structure 104, and the top surface 120A of the cathode ring 120 have the same height.

[0038] At operation 306, such as Figure 3 As shown in Figure D, adhesive material 404 is deposited above the substrate. Adhesive material 404 is deposited above the metal structure 104, the cathode ring 120, and the overhang gap filling structure 126. In one or more embodiments, adhesive material 404 is deposited using evaporation deposition. At operation 308, the adhesive material is etched to form an adhesive layer. Photoresist is disposed above a portion of the adhesive material 404. The photoresist is patterned to protect portions of the adhesive material 404 from the etching process. The photoresist is patterned such that it protects the portion of adhesive material 404 disposed above the overhang gap filling structure 126. The adhesive material 404 above the metal structure 104 and the cathode ring 120 is etched away.

[0039] At operation 310, such as Figure 3 As shown in Figure E, a suspended structure 110 is formed. The suspended structure 110 is formed above the adhesive layer 180 and each suspended space filling structure 126. Figure 3 As shown in E, the suspended structure 110 can be formed by depositing a first suspended layer and a second suspended layer, and then using photoresist to etch away the desired area to form the suspended structure.

[0040] Following operation 310, further processing can be performed. For example, OLED material, cathode, and encapsulation layers can be deposited to complete the sub-pixel circuit 100. This operation can be repeated until the desired number of sub-pixels are formed. An example of a complete sub-pixel is shown... Figure 1A middle.

[0041] In summary, an apparatus is disclosed. The apparatus is a sub-pixel circuit comprising a substrate, a plurality of sub-pixels, and a cathode ring. Sub-pixels are formed above the substrate. Each sub-pixel includes at least a metal structure (e.g., an anode), an adhesive layer, a suspended structure, a gap-filling structure, an organic light-emitting diode (OLED) material, a cathode, and an encapsulation material. The metal structure is defined by adjacent suspended structures. The suspended structures are disposed above the adhesive layer. The suspended structures include a second structure disposed above the first structure. The bottom surface of the second structure extends laterally across the upper surface of the first structure. The OLED material is disposed above the metal structure and the inorganic layer. The cathode is disposed above the OLED material. The encapsulation layer is disposed at least above the cathode material. The cathode ring is disposed around the perimeter of the sub-pixel circuit. In one or more embodiments, a second portion of the suspended structure extends above at least a portion of the cathode ring. The adhesive layer provided herein reduces delamination and increases adhesion between the gap-filling material and the suspended structure.

[0042] While the foregoing relates to embodiments of this disclosure, other and further embodiments of this disclosure may be designed without departing from its essential scope, the scope of which is defined by the foregoing claims.

Claims

1. A sub-pixel circuit, the sub-pixel circuit comprising: substrate; Multiple metal structures are disposed above the substrate; Multiple suspended space gap filling structures; Multiple suspended structures, the multiple suspended structures including extensions disposed through the sidewalls of the suspended structures; An adhesive layer is disposed above each cantilever gap-filling structure; Organic light-emitting diode (OLED) material, wherein the OLED material is disposed above each metal structure; Cathode, wherein the cathode is disposed above the OLED material; and A cathode ring is disposed above the substrate.

2. The sub-pixel circuit of claim 1, wherein adjacent overhang gap filling structures have at least one of the plurality of metal structures disposed therebetween.

3. The sub-pixel circuit of claim 1, wherein the cathode ring is disposed around the perimeter of the sub-pixel circuit.

4. The subpixel circuit of claim 3, wherein the subpixel circuit comprises at least two subpixels.

5. The sub-pixel circuit of claim 1, wherein the adhesive layer comprises tin oxide (SnO2).

6. The sub-pixel circuit of claim 1, wherein the sub-pixel circuit further comprises an encapsulation layer disposed above the cathode and passing through an end point of the cathode.

7. The sub-pixel circuit of claim 1, wherein the cathode ring comprises multiple layers.

8. The sub-pixel circuit of claim 1, wherein the cathode ring and the metal structure comprise the same material.

9. A sub-pixel circuit, the sub-pixel circuit comprising: substrate; Multiple sub-pixels, each of the multiple sub-pixels comprising: Multiple suspended structures are disposed above the substrate, and each suspended structure includes: First structure; Second structure; and An extension portion is provided through the sidewall of the first structure; A metal structure disposed above the substrate; An adhesive layer is disposed beneath the first structure of the plurality of suspended structures; Suspended space gap filling structure; Organic light-emitting diode (OLED) material, the OLED material being disposed above the metal structure; and Cathode, wherein the cathode is disposed above the OLED material; and A cathode ring is disposed around the perimeter of the sub-pixel circuit.

10. The sub-pixel circuit of claim 9, wherein the adhesive layer is deposited using evaporation deposition.

11. The sub-pixel circuit of claim 9, wherein the suspended space gap filling structure is disposed below the first structure of each of the plurality of suspended structures.

12. The sub-pixel circuit of claim 9, wherein adjacent overhang gap filling structures have the metal structure disposed therebetween.

13. The sub-pixel circuit of claim 9, wherein the cathode ring and the metal structure comprise the same material.

14. The sub-pixel circuit of claim 9, wherein the sub-pixel circuit further comprises: An encapsulation layer is disposed above the cathode and passing through the endpoint of the cathode, wherein the encapsulation layer extends below at least a portion of the extension of the suspended structure, along the sidewall of the suspended structure, and contacts the bottom surface of the extension of the suspended structure.

15. A method comprising: An adhesive material is deposited on a substrate, the substrate comprising multiple metal structures, multiple overhang gap filling structures, and a cathode ring; Multiple portions of the adhesive material are removed, such that the adhesive layer is at least partially disposed above the multiple cantilever gap-filling structures; A plurality of suspended structures are formed above the adhesive layer above the plurality of suspended gap filling structures, the suspended structures including extensions disposed through the sidewalls of the suspended structures; Organic light-emitting diode (OLED) material is deposited on the substrate, and the OLED material is disposed on the metal structure; and A cathode is deposited, wherein the cathode is disposed below each extension of the suspended structure.

16. The method of claim 15, further comprising: An encapsulation layer is deposited above the cathode and past the endpoint of the cathode, wherein the encapsulation layer extends along the sidewall of the suspended structure below at least a portion of the extensions of the plurality of suspended structures and contacts the bottom surface of the extensions of the suspended structure.

17. The method of claim 15, wherein the plurality of metal structures comprise a plurality of layers, and the cathode ring comprises a plurality of layers.

18. The method of claim 15, wherein the plurality of metal structures and the cathode ring are simultaneously deposited on the substrate.

19. The method of claim 15, wherein a plurality of portions of the adhesive layer are removed by an etching process.

20. The method of claim 15, wherein the adhesive layer comprises tin oxide (SnO2).

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