Organic light emitting diode display panel with moisture-proof structure

Abstract

The present invention discloses a display having an organic light emitting diode pixel formed by a thin film circuit. The thin film circuit may be formed in a thin film transistor (TFT) layer, and the organic light emitting diode may include an anode and a cathode and an organic emission layer formed above the TFT layer between the anode and the cathode. The organic emission layer may be formed via chemical evaporation technology. The display may include a moisture-proof structure, such as an organic emission layer disconnect structure, which introduces one or more gaps in the organic emission layer during evaporation, so that any potential moisture penetration path from the edge of the display panel to the active area of ​​the display is completely terminated.

Description

[0001] This patent application claims priority to U.S. Patent Application No. 16 / 670,071 filed on October 31, 2019 and U.S. Provisional Patent Application No. 62 / 788,562 filed on January 4, 2019, which are hereby incorporated by reference in their entirety. Background Art

[0002] The present invention relates generally to electronic devices, and more particularly to electronic devices having displays.

[0003] Electronic devices such as cell phones, computers, and other electronic devices often include displays. The display includes an array of pixels for displaying images to a user. In an organic light emitting diode display, each light emitting diode has electrodes (i.e., an anode and a cathode). An emissive material is interposed between the anode electrode and the cathode electrode. During operation, current passes between the anode and cathode electrodes through the emissive material to generate light.

[0004] The display panel of the electronic device has an effective display area within one or more display panel edges. A thin film encapsulation layer can be used to protect pixels formed by thin film circuits in the effective area of ​​the display. The thin film encapsulation layer can help protect the pixels from damage caused by environmental exposure. When encapsulation materials are used to form a display, one or more dam structures must be formed along one or more display panel edges to accommodate the encapsulation layer. However, the formation of the dam structure may increase the display border width. In addition, in certain display arrangements where the emissive material (which is often an organic layer) extends all the way to the edge of the panel, there is a risk that moisture can still penetrate through the organic emissive layer into the effective area of ​​the display and below the thin film encapsulation layer, which can seriously damage and adversely affect the performance of the display. Summary of the invention

[0005] An organic light emitting diode (OLED) display may include a substrate having a panel edge, a thin film transistor (TFT) layer formed on the substrate, an anode layer and a cathode layer formed above the TFT layer, an organic emission layer formed between the anode layer and the cathode layer and extending from an active area of ​​the display to the panel edge, and an organic emission layer disconnect structure formed at least partially through the TFT layer. The organic emission layer disconnect structure is configured to prevent moisture from penetrating into the active area of ​​the display through the organic emission layer by introducing one or more gaps in the organic emission layer. The organic emission layer may be formed via a chemical evaporation deposition technique. Therefore, the organic emission layer disconnect structure may sometimes be referred to as an evaporation layer gap generation structure.

[0006] The organic emission layer disconnect structure may include one or more grooves formed at least partially through the TFT layer. In one variation, the groove may have an enlarged sidewall to form an overhanging portion without organic emission material. In another variation, the groove may have an independently etched undercut portion without organic emission material. In another variation, the groove may have a sidewall with a plurality of levels of protrusions, wherein the portion below each protrusion is free of organic emission material. If desired, the groove may have an undercut / overhanging recessed portion formed at the topmost opening of the groove. In other suitable arrangements, the groove may have an undercut / overhanging recessed portion formed at an intermediate depth between the topmost opening and the bottom of the groove. If desired, the groove may form an undercut portion on only one side of the groove.

[0007] Generally speaking, the organic emission layer disconnect structure may be formed between the crack stopper structure and the active area. The crack stopper structure may be configured to prevent cracks from propagating from the edge of the panel into the display. In other suitable arrangements, the organic emission layer disconnect structure may be formed at the edge of the panel beyond the edge of the crack stopper structure (if any). In some embodiments, the organic emission layer disconnect structure may also be an island structure with an undercut region, wherein the undercut region is formed on at least one side of the island structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a schematic diagram of an illustrative electronic device with a display according to one embodiment.

[0009] Figure 2 is a cross-sectional side view of a portion of an illustrative display according to one embodiment.

[0010] Figure 3 is a cross-sectional side view of an edge portion of a display having a dam and crack stopper border structure.

[0011] Figure 4 is a cross-sectional side view of an edge portion of a display panel having an exemplary vapor-deposition layer disconnection structure according to an embodiment.

[0012] Figure 5 is a diagram showing how an organic layer may be formed on a display panel via evaporation according to one embodiment.

[0013] Figure 6-Figure 11 is a cross-sectional side view showing different types of evaporated layer disconnection structures according to certain embodiments.

[0014] Fig.12 and Fig.13 is a cross-sectional side view of an exemplary single-sided evaporated layer disconnection structure according to some embodiments.

[0015] Fig.14A , Fig. 14B and Fig. 14C is a cross-sectional side view of an exemplary island structure having undercuts on both sides, according to certain embodiments. DETAILED DESCRIPTION

[0016] Figure 1 An illustrative electronic device of the type that may be provided with a display is shown in FIG. Figure 1 The electronic device 10 may be a tablet computer, a laptop computer, a desktop computer, a monitor including an embedded computer, a monitor not including an embedded computer, a display for use with a computer or other device external to the display, a cellular phone, a media player, a watch device or other wearable electronic device, or other suitable electronic device.

[0017] like Figure 1 As shown, electronic device 10 may have control circuitry 16. Control circuitry 16 may include storage and processing circuitry for supporting the operation of device 10. The storage and processing circuitry may include storage devices such as hard drive storage devices, non-volatile memory (e.g., flash memory or other electrically programmable read-only memory configured to form a solid-state drive), volatile memory (e.g., static or dynamic random access memory), and the like. The processing circuitry in control circuitry 16 may be used to control the operation of device 10. The processing circuitry may be based on one or more microprocessors, microcontrollers, digital signal processors, baseband processors, power management units, audio chips, application specific integrated circuits, and the like.

[0018] Input-output circuitry in device 10, such as input-output devices 12, may be used to allow data to be supplied to device 10, and to allow data to be provided from device 10 to external devices. Input-output devices 12 may include buttons, joysticks, scroll wheels, touch pads, keypads, keyboards, microphones, speakers, audio generators, vibrators, cameras, sensors, light-emitting diodes and other status indicators, data ports, etc. A user may control the operation of device 10 by supplying commands through input-output devices 12, and may receive status information and other output from device 10 using the output resources of input-output devices 12.

[0019] Input-output devices 12 may include one or more displays, such as display 14. Display 14 may be a touch screen display that includes a touch sensor for acquiring touch input from a user, or display 14 may be insensitive to touch. The touch sensor of display 14 may be based on an array of capacitive touch sensor electrodes, an acoustic touch sensor structure, a resistive touch component, a force-based touch sensor structure, a light-based touch sensor, or other suitable touch sensor arrangements.

[0020] Control circuitry 16 may be used to run software, such as operating system code and application programs, on device 10. During operation of device 10, software running on control circuitry 16 may display images on display 14 using an array of pixels in display 14.

[0021] Display 14 may be an organic light emitting diode display or other suitable display. Configurations in which display 14 is an organic light emitting diode display are sometimes described herein as an example.

[0022] Display 14 may have a rectangular shape (ie, display 14 may have a rectangular footprint and a rectangular perimeter edge extending around the rectangular footprint) or may have other suitable shapes. Display 14 may be planar or may have a curved profile.

[0023] like Figure 1 As shown, display 14 may have an array of pixels 18 configured to display images to a user. Pixels 18 may each include one or more thin film transistors 22 for forming pixel control circuitry, and may each include a corresponding organic light emitting diode 20 controlled by the pixel control circuitry of the pixel 18. Pixels 18 may be formed within an active area AA of display 14. The active area of ​​display 14 may be at least partially surrounded by an inactive border area (sometimes referred to as a display panel edge area). Display driver circuitry 24 may be formed of thin film transistor circuitry and / or one or more integrated circuits, and may be used to provide image data and control signals to pixels 18 during operation of display 14.

[0024] Figure 2 A cross-sectional side view of an exemplary organic light emitting diode display 14 is shown in FIG. Figure 2 As shown, display 14 may include a substrate layer such as substrate layer 36. Substrate 36 may be a planar layer or a non-planar layer and may be formed from plastic, a polymer, glass, ceramic, sapphire, metal, or other suitable substrate materials. Figure 3 In the example of , the substrate 36 may be an organic substrate formed of polyimide (PI), polyethylene terephthalate (PET) or polyethylene naphthalate (PEN) (as an example). The surface of the substrate 36 may be optionally covered with one or more buffer layers (e.g., an inorganic buffer layer, such as a silicon oxide layer, a silicon nitride layer, etc.).

[0025] A thin film transistor (TFT) layer 48 including a thin film transistor circuit may be formed on the substrate 36. The TFT circuit may include a thin film transistor, a capacitor, and other active / passive thin film structures. The thin film transistor layer 48 may include a semiconductor layer 60 formed over the substrate 36. The semiconductor layer 60 may be a silicon layer, such as a low temperature polysilicon layer, a semiconductor oxide layer, such as an indium gallium zinc oxide (IGZO) layer, or other semiconductor layers that may be used as a channel region of a thin film transistor. A first interlayer dielectric film ILD1 may be formed over the semiconductor layer 60. A gate structure such as a first gate conductor G1 may be formed on the layer ILD1. Formed in this manner, the layer ILD1 serves as a gate insulating film. A second interlayer dielectric film ILD2 may be formed over the G1 structure. Additional gate structures such as a second gate conductor G2 may be formed on the layer ILD2. A third interlayer dielectric film ILD3 may be formed over the G2 structure. Generally speaking, various ILD layers may be formed of inorganic dielectric materials such as silicon oxide.

[0026] Metal structures such as first source-drain conductor SD1 may be formed on layer ILD3. At least some of the SD1 metal structures may be electrically coupled to semiconductor layer 60 by forming contact holes through the ILD layer to serve as thin-film transistor source-drain terminals. Semiconductor layer 60, gate structures, and at least some of the source-drain terminals may be interconnected to serve as one or more thin-film transistors 22 in each pixel 18 (see FIG. Figure 1 ). A first planarization layer PLN1 formed of an organic dielectric material such as a polymer may be formed over the SD1 metal structure. Additional metal structures, such as a second source-drain conductor SD2, may be formed over the first planarization layer PLN1. At least some of the SD2 metal structures may be electrically coupled to the thin film transistor circuitry below through one or more through holes in layer PLN1. A second planarization layer PLN2 formed of an organic dielectric material (e.g., a polymer) may be formed over the SD2 metal structure. If desired, a thin film transistor passivation layer may be formed over the topmost TFT planarization layer.

[0027] The layers between substrate 36 and the TFT passivation layers (which include semiconductor layer 60 , various ILD layers, various gate layers, various source-drain layers, and various planarization layers) may sometimes be collectively referred to as TFT layers 48 . Figure 2The example of is merely exemplary, where TFT layer 48 includes one semiconductor layer, two different gate conductor layers, two different source-drain conductor layers, and two different planarization layers. If desired, thin film transistor layer 48 may include two or more semiconductor layers (e.g., a first silicon semiconductor layer, a second semiconductor oxide layer above or below the first silicon semiconductor layer, etc.), only one gate structure or more than two gate structures, only one source-drain structure or more than two source-drain structures, only one planarization layer or more than two planarization layers, or other suitable TFT stacks.

[0028] The organic light emitting diode structure may be formed on the thin film transistor layer 48. Each light emitting diode has a lower electrode and an upper electrode. In a "top emission" display, the lower electrode may be formed of a reflective conductive material such as a patterned metal to help reflect the light generated by the light emitting diode in an upward direction out of the display. The upper electrode (sometimes called a counter electrode) may be formed of a transparent or semi-transparent conductive layer (e.g., a thin layer of transparent or semi-transparent metal and / or a layer of indium tin oxide or other transparent conductive material). This allows the upper electrode to transmit light generated by the emissive material in the diode outwardly. In a "bottom emission" display, the lower electrode may be transparent (or semi-transparent) and the upper electrode may be reflective.

[0029] In the configuration where the anode is the lower electrode, various layers such as a hole injection layer, a hole transport layer, an emission material layer, an electron transport layer, and an electron injection layer may be formed above the anode and below the upper electrode (serving as the cathode of the diode). In the inverted configuration where the cathode is the lower electrode, various layers such as an electron injection layer, an electron transport layer, an emission material layer, a hole transport layer, and a hole injection layer may be stacked on top of the cathode and may be covered with an upper layer serving as the anode of the diode. One or both of the electrodes may reflect light.

[0030] In general, display 14 may use a configuration in which the anode electrode is closer to the display substrate than the cathode electrode, or a configuration in which the cathode electrode is closer to the display substrate than the anode electrode. In addition, both bottom emission arrangements and top emission arrangements may be used. A top emission display configuration in which the anode is at the bottom and the cathode is at the top is sometimes described herein as an example. However, this is merely illustrative. Any suitable display arrangement may be used if desired.

[0031] exist Figure 2In an exemplary configuration of , display 14 has a top emission configuration in which lower electrode 42 is an anode and upper electrode 46 is a cathode. Anode conductor 42 can be formed in an opening in a pixel defining layer PDL. Pixel defining layer PDL can be formed of a patterned photoimageable polymer. In each light emitting diode 20, an organic emissive material 44 is interposed between an anode layer 42 and a cathode layer 46. Anode structure 42 can be formed by patterning a metal layer on top of thin film transistor layer 48. Cathode 46 can be formed by a common conductive layer deposited on top of organic emissive layer 44. Cathode 46 is transparent so that light 24 can leave light emitting diode 20 as current flows through emissive material 44 between anode 42 and cathode 46.

[0032] The circuits in the active display area should be protected by a thin film encapsulation layer such as thin film encapsulation layer 70. Encapsulation layer 70 may, for example, include a first inorganic encapsulation layer and a second inorganic encapsulation layer and an organic encapsulation layer sandwiched between the first inorganic encapsulation layer and the second inorganic encapsulation layer. Thin film encapsulation layer 70 formed in this manner can help prevent moisture from damaging the conductive circuits in display 14.

[0033] Figure 3 FIG. 1 is a cross-sectional side view of display 14 having a dam and crack stopper border structure at the edge portion. Figure 3 As shown, thin film transistor layer 48 may be formed on substrate 36. Organic light emitting diode structures such as anode 42 and cathode 46 may be formed within active area AA of the display, where pixels form an image for viewing by a user of device 10. In conventional displays, whenever thin film encapsulation layer 70 is formed as part of a display stack, one or more dam structures 302 must be formed in the inactive area to help contain the organic encapsulation material within layer 70 (i.e., to help prevent the organic encapsulation material from leaking out of the display boundary edge during the formation of encapsulation layer 70). Dam structures 302 are typically formed on TFT layer 48 along the edges of encapsulation layer 70. However, the formation of dam structures 302 (which often include two or more protruding barrier structures formed across the surface of TFT layer 48) may increase the inactive boundary area.

[0034] The substrate layer 36 may be formed by cutting a common substrate into a plurality of display panels (eg, using a laser or other scribing technique). The TFT layer 48 formed on the substrate 36 typically includes various inorganic dielectric layers (eg, see Figure 24 and 70), are susceptible to cracking when the display panel is cut from a common substrate to form display panel edge 300. To prevent cracks and delamination of layer 48, display 14 may have a peripheral crack stopper structure (sometimes referred to as a crack prevention structure, crack stopper strip, crack stopper line, etc.), such as peripheral crack stopper structure 304. Crack stopper structure 304 may be used to prevent crack propagation from panel edge 300 and film delamination in layers of display 14, such as layer 48 and layer 70. Panel edge 300 may also be formed by, for example, constructing a hole at least partially through the display stack, where the hole may be near the peripheral boundary of display 14 or may be located somewhere near the center of display 14 in the active area.

[0035] Although thin film encapsulation layer 70 generally prevents moisture from penetrating into active circuits within display 14, in certain embodiments where organic emissive layer 44 extends all the way to display panel edge 300, moisture propagation is particularly favorable (e.g., in Figure 3 ), there is a risk that moisture may still penetrate into the active area of ​​the display through the organic emissive layer 44, as indicated by arrow 350. The emissive layer 44 may be formed on top of the TFT layer 48 above the dam structure 302 and the crack stopper structure 304, but below the thin film encapsulation layer 70, thereby providing a leakage or bypass path through which moisture may inadvertently leak into the active area of ​​the display.

[0036] According to one embodiment, display 14 has a structure that breaks or cuts off organic emission layer 44 in the panel edge region so that any potential moisture penetration path from the actual panel edge is cut off. Figure 4 4 is a cross-sectional side view of such a display 14 including an exemplary moisture resistant or moisture barrier structure 410. Figure 4 As shown, a moisture resistant / barrier structure 410 may be formed in place of the dam structure 302 between the active area AA of the display and the edge 400 of the display panel. The moisture resistant structure 410 may include one or more wells, channels, or grooves 412 such that when the organic emission layer 44 is formed, at least a portion 44' will be formed at the bottom of the grooves 412 so that the portion 44' is physically decoupled or separated from the layer 44 formed on top of these grooves 412. The grooves 412 may at least partially surround or completely surround the active circuitry within the active area of ​​the display 14 to ensure that any moisture propagation paths are terminated. Although not shown, the grooves 412 may optionally be filled with a non-organic material or other material that is not easily permeable to moisture.

[0037] Forming one or more physical gaps in the organic emissive layer 44 in this manner can help eliminate any risk of moisture penetration, even if the emissive layer 44 is to be used as Figure 4The arrangement shown in FIG. 4 extends all the way to the panel edge 400. Therefore, the moisture-proof structure 410 may sometimes be referred to as an organic emission layer disconnection structure, an organic emission layer cut-off structure, an organic emission layer moisture decoupling structure, or an organic emission layer gap generation structure. As described above, the organic layer disconnection structure 410 may also replace the dam structure 302 to help contain the thin film encapsulation layer 70 within the active area of ​​the display, which reduces the ineffective border area at the edge of the display.

[0038] Figure 5 is a diagram showing how an evaporation device can be used to form an organic emission layer 44 on the display 14. Figure 5 As shown, the display panel can be oriented to face downward while the chemical evaporation apparatus 500 deposits a layer of organic emissive material onto the display panel, as indicated by arrow 504. A mask layer such as an open face mask 502 can be used to selectively pattern locations that allow the organic emissive material to be dispensed on the display 14. Generally speaking, the organic emissive material can be deposited on the display using chemical vapor deposition (CVD), physical vapor deposition, vapor phase epitaxy, thermal oxidation, casting, or other types of thin film deposition processes. Although the moisture barrier structure 410 described herein involves cutting off the organic emissive layer or forming a gap in the organic emissive layer, the structure 410 can generally be used to disconnect any potentially problematic organic layer in the display stack formed by evaporation that is sensitive to moisture penetration.

[0039] Chemical vapor deposition techniques are limited in the sense that specific exposed surfaces will only be coated when the duration and angle of deposition are well controlled. The organic layer disconnect structure 410 exploits this limitation of chemical vapor deposition by employing narrow trenches in the thin film transistor layer 48, such that the evaporation will not be able to adequately reach or coat the sidewalls of these narrow trenches. Therefore, the structure 410 that exploits this particular finding is sometimes referred to as an evaporated layer disconnect structure.

[0040] Figure 6-Figure 11 is a cross-sectional side view showing different types of evaporated layer disconnection structures 410 . Figure 6 A first suitable embodiment of structure 410 is shown having a narrow trench 600 (sometimes referred to as a recessed portion). Trench 600 may be formed only partially through TFT layer 48 (e.g., trench 600 may cut through any number of planarization, metal, gate, and / or dielectric layers in TFT layer 48), or may be formed all the way through TFT layer 48 (i.e., such that trench 600 passes completely through layer 48). Trench 600 should be configured to have an appropriate width and depth so that only a small portion of emissive material 44' will be formed at the bottom of trench 600, while the sidewalls of trench 600 are free of any organic emissive material. By ensuring that the sidewalls of trench 600 are free of any organic emissive material deposited, structure 410 introduces a physical gap in organic emissive layer 44, which cuts off or terminates any potentially problematic moisture penetration paths.

[0041] Figure 7 Another suitable embodiment is shown in which structure 410 has a narrow trench 700 with enlarged sidewalls. Trench 700 may extend only partially or completely through TFT layer 48. Trench 700 should be configured to have an appropriate width and depth so that only a small portion of emissive material 44' will be formed at the bottom of trench 700, while the sidewalls of trench 700 are free of any organic emissive material. Figure 7 As shown, the trench sidewall 702 can be further etched to form an undercut 704 at the opening of the trench 700. The undercut shape can also be referred to as an overhang. The final depth of the trench 700 and the undercut sidewall 702 can be formed simultaneously using the same etchant. The formation of the trench overhang can also ensure that the evaporated emitter material will not be deposited in the undercut area 704, thereby terminating any potentially problematic moisture penetration path.

[0042] Fig. 8A Another suitable embodiment is shown in which structure 410 has a trench 800 with an undercut portion 802 formed using a separate etching operation. Trench 800 may extend only partially or completely through TFT layer 48. Trench 800 may be similar to Figure 6 Groove 600 or Figure 7 The trench 700 is relatively wider, and therefore, at least some of the emitting material may extend down into the trench 800. If possible, the amount of emitting material deposited on the sidewalls should be kept to a minimum. However, the undercut portion 802 will ensure that the small amount of emitting material 44' at the bottom of the trench 800 is completely disconnected from the above-mentioned emitting material.

[0043] The undercut portion 802 may be formed using a separate etchant. Figure 8B 4 shows how the structure 410 may be initially filled with at least two different types of materials. Figure 8B As shown, before forming the organic emission layer, the trench 800 may be initially filled with a dielectric material ILD and a metal M. The dielectric material ILD may be removed using a first etchant that selectively targets the dielectric material without etching the metal. Then, the metal M may be removed using a second etchant that selectively targets the metal material without etching the dielectric. Using a separate etchant to form the undercut portion 802 in this manner provides enhanced selectivity. This helps ensure that the undercut portion 802 has an appropriate shape so that the organic emission material is not deposited therein, thereby terminating any potentially problematic moisture penetration paths.

[0044] Fig. 9 Another suitable arrangement including multiple layers of undercuts is shown. Fig. 9As shown, structure 410 may include a trench 900 having sidewalls with multiple levels of undercut / overhanging portions. Trench 900 may extend only partially or entirely through TFT layer 48. TFT layer 48 may generally include alternating layers of material. For example, TFT layers 48-1 and 48-3 may be silicon oxide layers, while TFT layers 48-2 and 48-4 may be silicon nitride layers. These alternating layers may have different etch rates or may be etched using different etchants to produce Fig. 9 A small amount of emitting material 44' may be deposited at the bottom of the trench 900. Although a small amount of emitting material may be formed on multiple levels of sidewall protrusions (see portion 902), the undercut area under each protrusion / overhang should be completely free of any evaporated organic emitting material.

[0045] exist Fig. 9 In the example of , three undercut regions are formed vertically relative to each other, which is merely illustrative. In general, structure 410 may include sidewalls having only two stacked undercut portions, more than three stacked undercut portions, 4-10 vertically stacked undercut / overhang portions, or any suitable number of protrusions. Fig. 9 The multi-layer undercut construction creates multiple opportunities to disconnect or sever the organic emission layer 44, thereby eliminating any potentially problematic moisture penetration paths.

[0046] Fig.10 Another example is shown, where a structure 410 has a trench 1000 having an upper layer 48-1 that forms a necessary undercut portion and a lower layer 48-2 that forms the remainder of the trench 1000. Specifically, the upper layer 48-1 may include multiple stacked metal layers, each of which has a different etch rate. Thus, a single etching operation may be used to simultaneously etch away multiple metal layers 48-1 to generate an undercut portion 1002.

[0047] Fig.10 A configuration in which the uppermost portion 48 - 1 is partially etched away may result in an accumulation of emitter material at the lip of the trench opening during evaporation, which may subject that portion to potential cracking. Fig.11Another suitable embodiment is shown in which structure 410 has a trench 1100 having an upper layer 48-1 with straight sidewalls 1102, a middle layer 48-2 forming the necessary undercut portion, and a lower layer 48-3 forming the remainder of the trench 1100. The vertical sidewalls 1102 provide a more robust trench opening that is less prone to breakage. Although some emissive material may coat the sidewalls 1102 near the opening of the trench 1100, the undercut portion 1104 in layer 48-2 will be free of any evaporated organic emissive material. For example, layer 48-2 may include multiple stacked metal layers, each of which has a different etch rate. Thus, a single etching operation can be used to simultaneously etch away multiple metal layers 48-2 to generate undercut portion 1104.

[0048] The emitter material is disconnected from both or all sides of the groove. Figure 6-Figure 11 The examples are for illustrative purposes only. Fig.12 4 shows how the organic vapor deposition disconnection structure 410 forms an undercut portion 1200 on only one side of the trench. Fig.12 As shown, the emission material 44' at the bottom of the groove may be connected (from the right) to the emission layer 44 formed on the top surface of layer 48, but will still be disconnected on the left due to the undercut portion 1200. As long as there is a gap on at least one side of the groove, the moisture permeation path through the organic emission layer 44 will be completely disconnected. In some embodiments, this single-sided undercut structure can be optionally implemented near the edge of the panel (see, for example, Fig.13 ).like Fig.13 As shown, the disconnected or isolated emitting material 44' may extend all the way to the display panel edge 1300, while the undercut portion 1200 on the other end will prevent any physical contact between the emitting material 44' and the emitting layer 44 extending from the left. Fig.13 The undercut portion 1200 may be located outside the crack stop structure 44 (if present) (see Figure 4 ).

[0049] The organic emission layer disconnection structure 410 includes only the grooves formed in the TFT layer 48. Figure 6-Figure 12 The examples are illustrative only. Fig.14A , Fig. 14B and Fig. 14C is a cross-sectional side view showing how an organic emission layer can also be disconnected using an island structure with an undercut or overhang on one or both sides of the island. Fig.14A A first exemplary configuration is shown, in which the Fig. 8A The islands are formed by undercutting areas of the type described. Fig. 14B Another exemplary configuration is shown, in which the Fig. 9 A plurality of undercut protrusions of the type described are used to form islands. Fig. 14CAnother exemplary configuration is shown, in which the Fig.10 If desired, one or more island structures may be constructed by forming any type of undercut regions on either side of the island so that the organic emission material deposited on the island is disconnected from the emission layer extending from the left or right side of the display panel.

[0050] See again Figure 4 In the example of FIG. 1 , the display 14 may include a moisture-proof structure 410 having at least two organic vapor deposition layer disconnection grooves. This is merely exemplary and is not intended to limit the scope of the embodiments of the present invention. If desired, the structure 410 may include only one groove, two grooves, or more than two grooves, which may be formed between the active area of ​​the display and the crack stopper structure (e.g., Figure 4 ) or may optionally be formed at the edge of the display panel (as shown in the configuration of Fig.13 In the case where multiple grooves are formed, the grooves may be of the same type (for example, both grooves may have a configuration selected from Figure 6-Figure 12 The same trench structure of any one of them) to simplify the manufacturing process or can be of different types (for example, the first trench can have Fig. 8A The second groove may have a Fig. 9 The trench structure of FIG. 4 is provided to further ensure that the emitter layer 44 is disconnected by one or more gaps. If necessary, one or more island structures such as Fig.14A , Fig. 14B and Fig. 14C An island structure can be formed in the panel edge area to help terminate any potential moisture penetration path. Figure 6-Figure 1 The various organic vapor deposited layer disconnect structures of the types described are not mutually exclusive and may optionally be combined in a single electronic device display 14.

[0051] According to one embodiment, a display is provided, which includes a substrate having a panel edge, a thin film transistor (TFT) layer formed on the substrate, an organic light emitting diode display pixel structure formed in the TFT layer within an active area of ​​the display, an anode layer and a cathode layer formed above the TFT layer, an organic emission layer formed between the anode layer and the cathode layer and extending from the active area to the edge of the panel, and an organic emission layer disconnect structure formed at least partially through the TFT layer, the organic emission layer disconnect structure being configured to prevent moisture from penetrating into the active area of ​​the display through the organic emission layer.

[0052] According to another embodiment, the organic emission layer disconnection structure forms one or more gaps in the organic emission layer.

[0053] According to another embodiment, the organic emission layer disconnection structure is formed only partially through the TFT layer.

[0054] According to another embodiment, the organic emission layer disconnection structure includes a groove formed at least partially through the TFT layer.

[0055] According to another embodiment, the trench has enlarged sidewalls forming an overhanging portion that is free of organic emissive material.

[0056] According to another embodiment, the trench has an independently etched undercut portion that is free of organic emissive material.

[0057] According to another embodiment, the trench has a sidewall with a plurality of levels of protrusions, and a portion below each protrusion is free of the organic emission material.

[0058] According to another embodiment, the trench forms an undercut portion at a topmost opening of the trench.

[0059] According to another embodiment, the groove forms an undercut portion at an intermediate position between the topmost opening and the bottom of the groove.

[0060] According to another embodiment, the trench forms an undercut portion on only one side of the trench.

[0061] According to another embodiment, the organic emission layer disconnection structure includes a plurality of trenches formed at least partially through the TFT layer.

[0062] According to another embodiment, a display includes a crack stopper structure formed on a substrate, the crack stopper structure configured to prevent cracks from propagating from a panel edge into the display, and an organic emission layer disconnect structure interposed between the crack stopper structure and an active area of ​​the display.

[0063] According to another embodiment, a display includes a crack stopper structure formed on a substrate, the crack stopper structure configured to prevent cracks from propagating from a panel edge into the display, and an organic emission layer disconnect structure is formed at the panel edge beyond the crack stopper structure.

[0064] According to another embodiment, an organic emission layer disconnection structure includes an island structure having an undercut region formed on at least one side of the island structure and having no organic emission material.

[0065] According to one embodiment, a method for manufacturing a display is provided, the method including obtaining a substrate, forming a thin film transistor (TFT) layer on the substrate, forming an organic emission layer gap generating structure at least partially through the TFT layer, forming an anode layer on the TFT layer, and forming an organic emission layer above the anode layer, the organic emission layer gap generating structure introducing one or more gaps in the organic emission layer during formation of the organic emission layer to terminate a moisture permeation path in the organic emission layer.

[0066] According to another embodiment, the substrate extends beyond the edge and the organic emissive layer extends to the edge of the substrate.

[0067] According to another embodiment, forming the organic emission layer includes performing chemical evaporation.

[0068] According to another embodiment, forming an organic emission layer gap generating structure includes forming an undercut region where an organic emission material cannot be formed during chemical evaporation.

[0069] According to one embodiment, a display is provided, which includes a substrate, a thin film transistor layer formed above the substrate, an organic layer formed above the thin film transistor layer, and a moisture-proof structure formed at least partially through the thin film transistor layer, the moisture-proof structure being configured to introduce one or more gaps in the organic layer to disconnect any potential moisture penetration paths through the organic layer.

[0070] According to another embodiment, the organic layer includes a light emitting diode emission layer, and the moisture barrier structure includes an undercut portion devoid of any organic material.

[0071] The foregoing is merely illustrative and various modifications may be made to the embodiments described. The foregoing embodiments may be implemented independently or in any combination.

Claims

1. A display, comprising: a substrate having a panel edge; a thin film transistor (TFT) layer formed on the substrate, wherein an organic light emitting diode display pixel structure is formed in the TFT layer within an active area of ​​the display; an anode layer and a cathode layer, the anode layer and the cathode layer being formed above the TFT layer; an organic emission layer having a first portion formed between the anode layer and the cathode layer and a second portion extending to an edge of the panel; an organic emission layer disconnect structure formed at least partially through the TFT layer, wherein the organic emission layer disconnect structure is configured to create a gap that physically separates the first portion from the second portion; as well as A crack stopper structure is formed on the substrate and in the TFT layer, wherein the crack stopper structure extends over the TFT layer, and wherein the organic emission layer is formed over the crack stopper structure. 2 . The display of claim 1 , wherein the organic emission layer disconnection structure forms one or more additional gaps in the organic emission layer. 3 . The display according to claim 1 , wherein the organic emission layer disconnection structure is formed only partially through the TFT layer. 4 . The display of claim 1 , wherein the organic emission layer disconnection structure comprises a groove formed at least partially through the TFT layer. 5 . The display of claim 4 , wherein the trench has enlarged sidewalls forming an overhang portion devoid of organic emissive material. The display of claim 4 , wherein the trench has an independently etched undercut portion devoid of organic emissive material. 7 . The display according to claim 4 , wherein the groove has a sidewall with a plurality of levels of protrusions, and wherein a portion below each of the protrusions is free of an organic emission material.

8. The display of claim 4, wherein the trench forms an undercut portion at a topmost opening of the trench.

9. The display of claim 4, wherein the groove forms an undercut portion at an intermediate position between a topmost opening and a bottom of the groove.

10. The display of claim 4, wherein the groove forms an undercut portion on only one side of the groove. 11 . The display of claim 1 , wherein the organic emission layer disconnection structure comprises a plurality of trenches formed at least partially through the TFT layer. 12 . The display of claim 1 , wherein the organic emission layer disconnect structure is interposed between the crack stopper structure and the active area of ​​the display. 13 . The display of claim 1 , wherein the organic emission layer disconnection structure is formed at an edge of the panel beyond the crack stopper structure. 14 . The display of claim 1 , wherein the organic emission layer disconnection structure comprises an island structure having an undercut region, the undercut region being formed on at least one side of the island structure and being free of an organic emission material.

15. A method of manufacturing a display, comprising: Obtaining a substrate; forming a thin film transistor (TFT) layer on the substrate; forming an organic emission layer gap generating structure at least partially through the TFT layer; forming an anode layer on the TFT layer; forming an organic emission layer over the anode layer, wherein an organic emission layer gap creation structure introduces one or more gaps in the organic emission layer during formation of the organic emission layer; as well as A crack stopper structure is formed on the substrate and in the TFT layer, wherein the crack stopper structure extends over the TFT layer, and wherein the organic emission layer is formed over the crack stopper structure. 16 . The method of claim 15 , wherein the substrate extends beyond an edge, and the organic emission layer extends to the edge of the substrate. The method according to claim 15 , wherein forming the organic emission layer comprises performing chemical evaporation. 18 . The method of claim 17 , wherein forming the organic emission layer gap creation structure comprises forming an undercut region in which an organic emission material cannot be formed during the chemical evaporation deposition.

19. A display comprising: substrate; a thin film transistor layer, the thin film transistor layer being formed above the substrate; an organic layer formed above the thin film transistor layer; a moisture barrier structure formed at least partially through the thin film transistor layer, wherein the moisture barrier structure is configured to introduce one or more gaps in the organic layer; as well as A crack stopper structure is formed on the substrate and in the TFT layer, wherein the crack stopper structure extends over the TFT layer, and wherein the organic layer is formed over the crack stopper structure.

20. The display of claim 19, wherein the organic layer comprises a light emitting diode emitting layer, and wherein the moisture barrier structure comprises an undercut portion devoid of any organic material.

Images