Display device

Abstract

A display device is provided. The display device includes a transistor disposed on a substrate, a light emitting diode electrically connected to the transistor, a first inorganic encapsulation layer disposed on the light emitting diode, an organic encapsulation layer, a second inorganic encapsulation layer disposed on the organic encapsulation layer, the second inorganic encapsulation layer includes a first sub-layer disposed on the organic encapsulation layer and a second sub-layer disposed on the first sub-layer, the density of the first sub-layer being lower than the density of the second sub-layer.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0140259 filed in the Korean Intellectual Property Office on October 19, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a display device. Background Art

[0004] The display device may include pixels and may display an image on a display screen by controlling the brightness of each pixel.

[0005] The display device may include a touch sensor capable of detecting a user's touch.

[0006] The display device may include a display panel on which pixels are formed.

[0007] A touch sensor may be provided on the display panel.

[0008] For example, the display panel may include a touch sensor, or a panel including a touch sensor may be attached to the display panel.

[0009] It should be understood that this background technology section is intended to provide, in part, a useful background for understanding the technology. However, this technical background section may also include ideas, concepts, or understandings that were not known or understood by those skilled in the relevant art before the corresponding effective filing date of the subject matter disclosed herein. Utility Model Content

[0010] Embodiments are directed to improving the reliability of a display device by providing an inorganic encapsulation layer having hygroscopicity.

[0011] According to an embodiment, a display device may include: a transistor arranged on a substrate; a light emitting diode electrically connected to the transistor; a first inorganic encapsulation layer arranged on the light emitting diode; an organic encapsulation layer arranged on the first inorganic encapsulation layer; and a second inorganic encapsulation layer arranged on the organic encapsulation layer, wherein the second inorganic encapsulation layer may include a first sublayer arranged on the organic encapsulation layer; and a second sublayer arranged on the first sublayer, wherein the density of the first sublayer is lower than the density of the second sublayer, and the thickness of the first sublayer is in the range of about 800 angstroms to about 1200 angstroms.

[0012] The second sub-layer may have a thickness in a range of about 6000 angstroms to about 7000 angstroms.

[0013] The first sub-layer and the second sub-layer may be made of the same material.

[0014] The first sublayer may further include oxygen (O).

[0015] The first sub-layer may include an amount of oxygen greater than an amount of oxygen contained in the second sub-layer.

[0016] The first sub-layer may comprise a moisture absorption capacity greater than the moisture absorption capacity of the second sub-layer.

[0017] The first inorganic encapsulating layer may include silicon oxynitride, and the first and second sublayers may include silicon nitride.

[0018] An upper surface of the organic encapsulation layer may include an uneven surface.

[0019] The first sub-layer may cover an uneven surface of an upper surface of the organic encapsulation layer.

[0020] An upper surface of the first sub-layer may include an uneven surface.

[0021] According to an embodiment, a display device may include: a transistor arranged on a substrate; a light emitting diode electrically connected to the transistor; a first inorganic encapsulation layer arranged on the light emitting diode; an organic encapsulation layer arranged on the first inorganic encapsulation layer; and a second inorganic encapsulation layer arranged on the organic encapsulation layer, wherein the second inorganic encapsulation layer may include: a first sublayer arranged on the organic encapsulation layer; and a second sublayer arranged on the first sublayer, wherein the density of the first sublayer is lower than the density of the second sublayer, and the moisture absorption amount of the first sublayer is approximately 1×10 15 molecules / cm 2 Or more.

[0022] The first sub-layer may have a thickness in a range of about 800 angstroms to about 1200 angstroms.

[0023] The second sub-layer may have a thickness in a range of about 6000 angstroms to about 7000 angstroms.

[0024] The first sub-layer and the second sub-layer may be made of the same material.

[0025] The first sublayer may further include oxygen (O).

[0026] The first inorganic encapsulating layer may include silicon oxynitride, and the first and second sublayers may include silicon nitride.

[0027] An upper surface of the organic encapsulation layer may include an uneven surface, and the first sublayer may cover the uneven surface.

[0028] An upper surface of the first sub-layer may include an uneven surface.

[0029] According to the embodiment, since the hygroscopicity of the inorganic encapsulation layer included in the display device is improved, the reliability of the display device may be improved by blocking a moisture permeation path caused by the penetration of external air or moisture. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The above and other aspects and features of the present disclosure will become more apparent by describing in detail embodiments of the present disclosure with reference to the accompanying drawings.

[0031] Figure 1 is a schematic perspective view illustrating a usage state of the display device according to the embodiment.

[0032] Figure 2 is an exploded perspective view of a display device according to an embodiment.

[0033] Figure 3 is a schematic perspective view schematically showing a display device according to an embodiment.

[0034] Figure 4 is a schematic cross-sectional view of a portion of a display panel according to an embodiment.

[0035] Figure 5 is a schematic cross-sectional view illustrating an encapsulation layer according to an embodiment.

[0036] Figure 6 Schematic diagram showing a moisture permeation path of external air in the embodiment.

[0037] Figure 7 Graph showing moisture absorption according to Examples and Comparative Examples.

[0038] Figure 8 is a graph showing film density according to energy used in a process of forming an inorganic encapsulation layer.

[0039] Figure 9 is a graph showing the amount of moisture absorption according to pressure conditions in a process of forming an inorganic encapsulation layer. DETAILED DESCRIPTION

[0040] Hereinafter, with reference to the accompanying drawings, various embodiments will be described in detail so that those skilled in the art can easily realize the present disclosure.

[0041] The present disclosure may be embodied in many different forms and is not limited to the embodiments described herein.

[0042] In order to clearly illustrate the present disclosure, parts irrelevant to the description may be omitted, and the same or similar components are assigned the same reference numerals throughout the specification.

[0043] In addition, the size and thickness of each component shown in the drawings are arbitrarily illustrated for convenience of explanation, and thus the present disclosure is not necessarily limited to the illustrated size and thickness.

[0044] In the drawings, thicknesses are exaggerated to clearly illustrate layers and regions.

[0045] Also, in the drawings, the thicknesses of some layers and regions are exaggerated for convenience of explanation.

[0046] In addition, when a part of a layer, film, region, plate, etc. is referred to as being “on” or “on” another part, this includes not only the case where it is “directly on” the other part, but also the case where the other part exists between them.

[0047] In contrast, when a part is referred to as being "directly on top of" another part, it means that there is no other part between them.

[0048] In addition, “above” or “on” a reference portion means disposed above or below the reference portion, and does not necessarily mean disposed “above” or “on” the reference portion in a direction opposite to gravity.

[0049] In addition, throughout the specification, when a part is referred to as “including” a certain component, it means that it may further include other components, but does not exclude other components, unless there is a particular description to the contrary.

[0050] In addition, throughout the specification, when “on a plane” is mentioned, this means when the target portion is viewed from above, and when “in a cross section” is mentioned, this means when the cross section of the target portion is cut vertically and viewed from the side.

[0051] As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0052] In the specification and claims, for the purposes of its meaning and interpretation, the term "and / or" is intended to include any combination of the terms "and" and "or." For example, "A and / or B" may be understood to mean "A, B, or A and B." The terms "and" and "or" may be used in either a conjunctive or disjunctive sense and may be understood to be equivalent to "and / or."

[0053] In the specification and claims, for purposes of its meaning and interpretation, the phrase "at least one of" is intended to include the meaning of "at least one selected from the group of." For example, "at least one of A and B" can be understood to mean "A, B, or A and B."

[0054] It will be understood that although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of this disclosure.

[0055] The term "overlap" or "overlapping" means that a first object can be above, below, or to one side of a second object, and vice versa. Additionally, the term "overlap" may include layering, stacking, facing, facing, extending over, covering, or partially covering, or any other suitable term as would be appreciated and understood by one of ordinary skill in the art.

[0056] The terms "facing" and "facing" mean that the first element can be directly or indirectly opposite to the second element. In the case where a third element is between the first and second elements, although still facing each other, the first and second elements can be understood as indirectly opposite to each other.

[0057] When an element is described as “not overlapping” or “will not overlap” another element, this may include the elements being spaced apart from each other, offset from each other, or positioned beside each other or any other appropriate terminology as would be appreciated and understood by one of ordinary skill in the art.

[0058] The terms “comprises,” “including,” “includes,” and / or “comprising,” “having,” “having,” and / or “having” and variations thereof when used in this specification specify the presence of stated features, integers, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0059] As used herein, "about" or "approximately" is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, taking into account the measurements in question and the errors associated with the measurement of a particular quantity (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations, or within ±30%, ±20%, ±10%, ±5% of the stated value.

[0060] Unless otherwise defined or implied herein, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present disclosure belongs. It will be further understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly defined as such herein.

[0061] It will be understood that in the specification, when an element (or region, layer, part, etc.) is referred to as being "on," "connected to" or "coupled to" another element, the element can be directly arranged on the other element mentioned above, directly connected or coupled to the other element mentioned above, or intervening elements can be arranged between them.

[0062] It will be understood that the terms "connected to" or "coupled to" may include physical or electrical connection or coupling.

[0063] The following will be Figure 1 and Figure 2 Discuss the schematic structure of the display device.

[0064] Figure 1 is a schematic perspective view showing a usage state of the display device according to the embodiment, and Figure 2 is an exploded perspective view of a display device according to an embodiment.

[0065] refer to Figure 1 The display device 1000 according to the embodiment is a device for displaying moving images or still images and can be used for mobile phones, smart phones or tablet personal computers. It can be used not only for portable electronic devices such as communication terminals, electronic notebooks, electronic books, portable multimedia players (PMPs), navigators and ultra-mobile PCs (UMPCs), but also as a display screen for various products such as televisions, laptop computers, monitors, billboards, Internet of Things (IOT) devices, etc.

[0066] The display device 1000 according to the embodiment may be mounted on a wearable device such as a smart watch, a watch phone, a glasses type display, and a head mounted display (HMD).

[0067] The display device 1000 according to an embodiment may include a dashboard of a car, a central information display (CID) or a room mirror display (instead of a display of a side-view mirror of a car) placed on the central dashboard or instrument panel of the car, and a display that can be used as entertainment for the rear seat of the car and as a display placed on the back of the front seat.

[0068] For ease of explanation, Figure 1 The display device 1000 is shown functioning as a smartphone.

[0069] The display device 1000 may display an image on a display surface parallel to each of the first direction DR1 and the second direction DR2 in the third direction DR3 .

[0070] The display surface on which an image is displayed may correspond to the front surface of the display device 1000 and the front surface of the cover window CW.

[0071] Images can include static images as well as dynamic images.

[0072] In this embodiment, the front (or top) surface and the back (or bottom) surface of each member are defined based on the direction in which the image is displayed.

[0073] The front surface and the rear surface are opposite to each other in the third direction DR3 , and a normal direction of each of the front surface and the rear surface may be parallel to the third direction DR3 .

[0074] A spaced distance between the front surface and the rear surface in the third direction DR3 may correspond to a thickness of the display panel in the third direction DR3.

[0075] The display device 1000 according to the embodiment may detect a user's input applied from the outside (refer to Figure 1 hand in the middle).

[0076] The user's input may include various types of external inputs such as a part of the user's body, light, heat, or pressure.

[0077] In an embodiment, the user's input is shown with the user's hand applied to the front.

[0078] However, the present disclosure is not limited thereto.

[0079] The user's input may be provided in various forms, and the display apparatus 1000 may also detect the user's input applied to the side or rear surface of the display apparatus 1000 according to the structure of the display apparatus 1000 .

[0080] refer to Figure 1 and Figure 2 , the display device 1000 may include a cover window CW, a housing HM, a display panel DP, and an optical element ES.

[0081] In an embodiment, the cover window CW and the housing HM may be combined to form the exterior of the display device 1000 .

[0082] The cover window CW may include an insulating panel.

[0083] For example, the cover window CW may be made of glass, plastic, or a combination thereof.

[0084] The front of the cover window CW may define the front of the display device 1000 .

[0085] The transmission area TA may be an optically transparent area.

[0086] For example, the transmission area TA may be an area having a visible light transmittance of about 90% or more.

[0087] The blocking area BBA may define the shape of the transmission area TA.

[0088] The blocking area BBA is adjacent to the transmission area TA and may surround the transmission area TA.

[0089] The blocking area BBA may be an area having relatively lower light transmittance than the transmission area TA.

[0090] The blocking area BBA may include an opaque material that blocks light.

[0091] The blocking area BBA may have a selectable color.

[0092] The blocking area BBA may be defined by a bezel layer provided separately from the transparent substrate defining the transmission area TA, or may be defined by an ink layer formed by interposing a transparent substrate or coloring the transparent substrate.

[0093] The display panel DP may include display pixels PX displaying an image and a driver 50 , and the display pixels PX are arranged in the display area DA and the assembly area EA.

[0094] The display panel DP may include a front surface including a display area DA and a non-display area PA.

[0095] In an embodiment, the display area DA and the element area EA are areas displaying an image, including pixels, and at the same time, they may be areas detecting an external input using a touch sensor arranged in a third direction DR3 of the pixels.

[0096] The transmission area TA of the cover window CW may at least partially overlap the display area DA and the assembly area EA of the display panel DP.

[0097] For example, the transmission area TA may overlap with the front surfaces of the display area DA and the assembly area EA, or may overlap with at least a portion of the display area DA and the assembly area EA.

[0098] Therefore, the user may view an image through the transmissive area TA or provide an external input based on the image.

[0099] However, the present disclosure is not limited thereto.

[0100] For example, the area where an image is displayed and the area where an external input is detected may be separated from each other.

[0101] The non-display area PA of the display panel DP may at least partially overlap with the blocking area BBA of the cover window CW.

[0102] The non-display area PA may be an area covered by the blocking area BBA.

[0103] The non-display area PA is adjacent to the display area DA and may surround the display area DA.

[0104] No image is displayed in the non-display area PA, and a driving circuit or driving wiring for driving the display area DA may be arranged.

[0105] The non-display area PA may include a first non-display area PA1 disposed outside the display area DA and a second non-display area PA2 including the driver 50 , the connection wiring, and the bending area.

[0106] exist Figure 2 In the embodiment of FIG. 5 , the first non-display area PA1 is arranged on three sides of the display area DA, and the second non-display area PA2 is arranged on the remaining side of the display area DA.

[0107] A portion of the non-display area PA of the display panel DP may be bent.

[0108] At this time, part of the non-display area PA is directed toward the rear of the display device 1000, so that the blocking area BBA visible on the front of the display device 1000 can be reduced. Figure 2 In the embodiment, the second non-display area PA2 may be bent and placed on the rear surface of the display area DA and assembled.

[0109] In addition, the assembly area EA of the display panel DP may include a first assembly area EA1 and a second assembly area EA2 .

[0110] The first assembly area EA1 and the second assembly area EA2 may be at least partially surrounded by the display area DA.

[0111] The first assembly area EA1 and the second assembly area EA2 are shown to be spaced apart from each other, but are not limited thereto and may be at least partially connected.

[0112] The first and second component areas EA1 and EA2 may be areas in which optical elements ES (hereinafter referred to as components) using infrared rays, visible light, or sound are arranged.

[0113] The display area DA (hereinafter also referred to as a main display area) and the assembly area EA are formed with a plurality of light emitting diodes and a plurality of pixel circuit parts that generate a light emitting current and transmit the light emitting current to each of the plurality of light emitting diodes.

[0114] Here, one light emitting diode and one pixel circuit portion are referred to as a display pixel PX.

[0115] One pixel circuit portion and one light emitting diode may be formed in the display area DA and the element area EA in a one-to-one ratio.

[0116] The first assembly area EA1 may include a display layer including a plurality of pixels and a transmissive portion through which light and / or sound may pass.

[0117] The transmissive portion is disposed between adjacent pixels and is composed of a layer through which light and / or sound can pass.

[0118] The transmission portion may be disposed between adjacent pixels, and according to an embodiment, a layer that does not transmit light, such as a light blocking member, may overlap the first assembly area EA1.

[0119] The number of pixels per unit area (hereinafter referred to as resolution) of the pixels contained in the display area DA (hereinafter referred to as normal pixels) and the number of pixels per unit area (hereinafter referred to as resolution) of the pixels contained in the first component area EA1 (hereinafter referred to as first component pixels) may be the same.

[0120] The second component area EA2 may include a region composed of a transparent layer so that light can pass therethrough (hereinafter also referred to as a light-transmitting region), and the light-transmitting region does not have a conductive layer or a semiconductor layer and may include a light-blocking material. A layer (e.g., a pixel-defining layer and / or a light-blocking member) may have a structure that does not block light by including an opening that overlaps with a position corresponding to the second component area EA2.

[0121] The number of pixels per unit area of pixels included in the second component area EA2 (hereinafter also referred to as second component pixels) may be smaller than the number of pixels per unit area of normal pixels included in the display area DA.

[0122] As a result, the resolution of the second component pixels may be lower than that of ordinary pixels.

[0123] The second non-display area PA2 may include a bent portion.

[0124] The display area DA and the first non-display area PA1 may have a flat state substantially parallel to a plane defined by the first direction DR1 and the second direction DR2, and the second non-display area PA2 may have a flat state. One side of the second non-display area PA2 may extend from the flat state, pass through the curved portion, and return to the flat state.

[0125] As a result, at least a portion of the second non-display area PA2 may be bent and assembled to be disposed on the rear side of the display area DA.

[0126] In a case where at least a portion of the second non-display area PA2 is assembled, it overlaps with the display area DA on a plane, and thus the blocking area BBA of the display device 1000 may be reduced.

[0127] The driver 50 may be mounted on the second non-display area PA2 , on the bent portion, or disposed on one of both sides of the bent portion.

[0128] The driver 50 may be provided in the form of a chip.

[0129] The driver 50 is electrically connected to the display area DA and the assembly area EA and may transmit electrical signals to pixels in the display area DA and the assembly area EA.

[0130] For example, the driver 50 may provide data signals to display pixels PX disposed or arranged in the display area DA.

[0131] By way of example, the driver 50 may include a touch driving circuit and may be electrically connected to the touch sensing unit (or portion) arranged in the display area DA and / or the assembly area EA.

[0132] The driver 50 may include various circuits other than the above-described circuits, or may be designed to provide various electrical signals to the display area DA.

[0133] The display device 1000 may have a pad portion disposed at an end portion of the second non-display area PA2 and may be electrically connected to a flexible printed circuit board (FPCB) including a driving chip through the pad portion.

[0134] Here, the driving chip disposed on the flexible printed circuit board may include various driving circuits for driving the display device 1000 or a connector for power supply.

[0135] According to an embodiment, a rigid printed circuit board (PCB) may be used instead of a flexible printed circuit board.

[0136] The optical element ES may be disposed under the display panel DP.

[0137] The optical element ES may include a first optical element ES1 overlapping the first component area EA1 and a second optical element ES2 overlapping the second component area EA2.

[0138] The first optical element ES1 may use infrared rays, and in this case, in the first component area EA1 , a layer that does not transmit light such as a light blocking member may overlap the first component area EA1 .

[0139] The first optical element ES1 may be an electronic element using light or sound.

[0140] For example, the first optical element ES1 is a sensor that receives and uses light (such as an infrared sensor), a sensor that outputs and detects light or sound to measure distance or recognize fingerprints, etc., a small lamp that outputs light, or a speaker that outputs sound.

[0141] Of course, in the case of an electronic component using light, light of various wavelength bands such as visible light, infrared light, and ultraviolet light can be used.

[0142] The second optical device ES2 may be at least one of a camera, an infrared camera (IR camera), a dot projector, an infrared illuminator (IR illuminator), and a time-of-flight sensor (ToF sensor).

[0143] The housing HM may be combined with the cover window CW.

[0144] A cover window CW may be placed on the front face of the housing HM.

[0145] The housing HM may be combined with the cover window CW to provide an optional receiving space.

[0146] The display panel DP and the optical element ES may be accommodated in an optional accommodation space provided between the housing HM and the cover window CW.

[0147] The housing HM may include a material having relatively high rigidity.

[0148] For example, the housing HM may include a plurality of frames and / or panels made of glass, plastic, or metal, or a combination thereof.

[0149] The housing HM may stably protect components of the display device 1000 accommodated in the internal space from external impacts.

[0150] In the following, we will Figure 3 The structure of the display device 1000 according to the embodiment will be described.

[0151] Figure 3 is a schematic perspective view schematically showing a light emitting display device according to an embodiment.

[0152] Descriptions of components identical to those described above will be omitted, and Figure 3 The embodiment shows a foldable display device in which the display device 1000 is folded by a folding axis FAX.

[0153] refer to Figure 3 In an embodiment, the display device 1000 may be a foldable display device.

[0154] The display apparatus 1000 may be folded outward or inward based on a folding axis FAX.

[0155] In a case of being folded outward based on the folding axis FAX, the display surface of the display device 1000 is located on both sides in the third direction DR3 , so that images can be displayed in two directions.

[0156] If the display surface is folded inward based on the folding axis FAX, it may not be visible from the outside.

[0157] In an embodiment, the display apparatus 1000 may include a display area DA, an assembly area EA, and a non-display area PA.

[0158] The display area DA may be divided into a 1-1 display area DA1-1, a 1-2 display area DA1-2, and a folding area FA.

[0159] The 1-1 display area DA1-1 and the 1-2 display area DA1-2 may be arranged on the left and right sides respectively based on the folding axis FAX (or centered around the folding axis FAX), and the folding area FA may be arranged between the 1-1 display area DA1-1 and the 1-2 display area DA1-2.

[0160] At this time, in a case of being folded outward based on the folding axis FAX, the 1-1 display area DA1-1 and the 1-2 display area DA1-2 are arranged on both sides in the third direction (DR3), which allows displaying images in two directions.

[0161] In addition, in a case where FAX is folded inward based on the folding axis, the 1-1 display area DA1-1 and the 1-2 display area DA1-2 may not be visible from the outside.

[0162] In the following, reference will be made to Figures 4 to 6 A display panel according to an embodiment is described.

[0163] Figure 4 is a schematic cross-sectional view of a portion of a display panel according to an embodiment, Figure 5 is a schematic cross-sectional view showing an encapsulation layer according to an embodiment, and Figure 6 is a diagram schematically illustrating a moisture permeation path of external air according to an embodiment.

[0164] First, refer to Figure 4 , the substrate SUB may include a material having rigid properties (such as glass) or a flexible material that can be bent (such as plastic or polyimide).

[0165] A buffer layer BF may be further disposed on the substrate SUB to planarize the surface of the substrate SUB and block penetration of impurity elements.

[0166] The buffer layer BF may include an inorganic material, for example, an inorganic insulating material (such as silicon nitride (SiN x), silicon oxide (SiO x ) or silicon oxynitride (SiO x N y )).

[0167] According to embodiments, the buffer layer BF may have a single-layer or multi-layer structure including one or more inorganic insulating materials.

[0168] A barrier layer (not shown) may be further disposed on the substrate SUB.

[0169] At this time, a barrier layer may be disposed between the substrate SUB and the buffer layer BF.

[0170] The barrier layer may include silicon nitride (SiN x ), silicon oxide (SiO x ) or silicon oxynitride (SiO x N y ) of inorganic insulating materials.

[0171] The barrier layer (not shown) may have a single-layer or multi-layer structure including one or more inorganic insulating materials.

[0172] The semiconductor layer ACT may be disposed on the substrate SUB.

[0173] The semiconductor layer ACT may include any one of amorphous silicon, polycrystalline silicon, and an oxide semiconductor.

[0174] For example, the semiconductor layer ACT may include low temperature polysilicon (LTPS) or an oxide semiconductor including at least one of zinc (Zn), indium (In), gallium (Ga), tin (Sn), and a mixture thereof.

[0175] For example, the semiconductor layer ACT may include indium gallium zinc oxide (IGZO).

[0176] The semiconductor layer ACT may include a channel region C, a source region S, and a drain region D divided according to whether the semiconductor layer is doped with impurities.

[0177] The source region S and the drain region D may have conductive properties corresponding to a conductor.

[0178] The first gate insulating layer GI1 may cover the semiconductor layer ACT and the substrate SUB.

[0179] The first gate insulating layer GI1 may include silicon nitride (SiN x ), silicon oxide (SiO x ) or silicon oxynitride (SiO x N y ) of inorganic insulating materials.

[0180] The first gate insulating layer GI1 may have a single-layer or multi-layer structure including one or more inorganic insulating materials.

[0181] The gate electrode GE1 may be located on the first gate insulating layer GI1 .

[0182] The gate electrode GE1 may include a metal or a metal alloy such as copper (Cu), molybdenum (Mo), aluminum (Al), silver (Ag), chromium (Cr), tantalum (TA), and titanium (Ti).

[0183] The gate electrode GE1 may be composed of a single layer or a multilayer.

[0184] A region of the semiconductor layer ACT overlapping with the planar gate electrode GE may be a channel region C.

[0185] The second gate insulating layer GI2 is disposed on the gate electrode GE1 .

[0186] The second gate insulating layer GI2 may include silicon nitride (SiN x ), silicon oxide (SiO x ), silicon oxynitride (SiO x N y ) and other inorganic insulating materials.

[0187] The second gate insulating layer GI2 may have a single-layer or multi-layer structure including one or more inorganic insulating materials.

[0188] The capacitor electrode GE2 may be located on the second gate insulating layer GI2.

[0189] The capacitor electrode GE2 may overlap with the gate electrode GE1 to form a capacitor.

[0190] The first insulating layer IL1 is disposed on the capacitor electrode GE2 .

[0191] The first insulating layer IL1 may include silicon nitride (SiN x ), silicon oxide (SiO x ) or silicon oxynitride (SiO x N y ) of inorganic insulating materials.

[0192] The first insulating layer IL1 may have a single-layer or multi-layer structure including one or more inorganic insulating materials.

[0193] The source electrode SE and the drain electrode DE may be located on the first insulating layer IL1 .

[0194] The source electrode SE and the drain electrode DE are respectively connected to the source region S and the drain region D of the semiconductor layer ACT through openings formed in the first insulating layer IL1 , the second gate insulating layer GI2 , and the first gate insulating layer GI1 .

[0195] Therefore, the semiconductor layer ACT, the gate electrode GE, the source electrode SE, and the drain electrode DE form one transistor.

[0196] According to an embodiment, the transistor may include only the source region and the drain region of the semiconductor layer ACT instead of the source electrode SE and the drain electrode DE.

[0197] The source electrode SE and the drain electrode DE may include aluminum (Al), copper (Cu), silver (Ag), gold (Au), platinum (Pt), palladium (Pd), nickel (Ni), molybdenum (Mo), tungsten (W), titanium (Ti), chromium (Cr), tantalum (TA), etc., and may include metal or metal alloy.

[0198] The source electrode SE and the drain electrode DE may be composed of a single layer or a multi-layer.

[0199] The source electrode SE and the drain electrode DE according to the embodiment may consist of three layers including an upper layer, a middle layer, and a lower layer, and the upper layer and the lower layer may include titanium (Ti), and the middle layer may include aluminum (Al).

[0200] A second insulating layer IL2 may be on the source electrode SE and the drain electrode DE.

[0201] The second insulating layer IL2 covers the source electrode SE and the drain electrode DE.

[0202] The second insulating layer IL2 serves to planarize the surface of the substrate SUB on which the transistor is mounted, and may be an organic insulating layer selected from the group consisting of polyimide, polyamide, acrylic resin, benzocyclobutene, and phenol resin, and may contain more than one substance.

[0203] The first electrode E1 may be located on the second insulating layer IL2 .

[0204] The first electrode E1 is also referred to as an anode electrode, and may be composed of a single layer including a transparent conductive oxide layer or a metal material, or a multilayer including these single layers.

[0205] The transparent conductive oxide layer may include indium tin oxide (ITO), polycrystalline ITO, indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), and indium tin zinc oxide (ITZO).

[0206] The metal material may include silver (Ag), molybdenum (Mo), copper (Cu), gold (Au), and aluminum (Al).

[0207] The first electrode E1 may be physically and electrically connected to the drain electrode DE through the opening in the second insulating layer IL2 .

[0208] Therefore, the first electrode E1 may receive an output current to be transmitted from the drain electrode DE to the light emitting layer EML.

[0209] A pixel defining layer PDL and a spacer SPC may be located on the first electrode E1 and the second insulating layer IL2 .

[0210] The pixel defining layer PDL may include a pixel opening OP1 overlapping at least a portion of the first electrode E1 .

[0211] At this time, the pixel opening OP1 may overlap with the center of the first electrode E1 and may not overlap with the edge of the first electrode E1.

[0212] Therefore, the size of the opening OP1 may be smaller than that of the first electrode E1.

[0213] The pixel defining layer PDL may define a formation position of the light emitting layer EML so that the light emitting layer EML may be located on the exposed portion of the upper surface of the first electrode E1 .

[0214] The pixel defining layer PDL and the spacer SPC may be organic insulating layers including one or more materials selected from the group consisting of polyimide, polyamide, acrylic resin, benzocyclobutene, and phenolic resin, and according to an embodiment, the pixel defining layer PDL may be formed of a black pixel defining layer (BPDL) including a black pigment.

[0215] The light emitting layer EML may be disposed in the pixel opening OP1 divided by the pixel defining layer PDL.

[0216] The light emitting layer EML may include an organic material that emits light such as red, green, and blue.

[0217] The light emitting layer EML emitting red, green, and blue light may include a low-molecular or high-molecular organic material.

[0218] exist Figure 4 In the figure, the light-emitting layer EML is shown as a single layer, but in fact, auxiliary layers such as an electron injection layer, an electron transport layer, a hole transport layer and a hole injection layer may also be included above and below the light-emitting layer EML, the hole injection layer and the hole transport layer may be arranged below the EML, and the electron transport layer and the electron injection layer may be arranged above the light-emitting layer EML.

[0219] The second electrode E2 may be disposed on the pixel defining layer PDL and the light emitting layer EML.

[0220] The second electrode E2 is also referred to as a cathode electrode.

[0221] In addition, the second electrode E2 may have a semi-transparent property, and in this case, it may form a microcavity together with the first electrode E1.

[0222] Depending on the microcavity structure, the spacing and characteristics between the two electrodes allow light of a selected wavelength to be emitted upward, and as a result, red, green, or blue can be displayed.

[0223] The encapsulation layer ENC may be located on the second electrode E2 .

[0224] The encapsulation layer ENC may include at least one inorganic layer and at least one organic layer.

[0225] In this embodiment, the encapsulation layer ENC may include a first inorganic encapsulation layer EIL1, an organic encapsulation layer EOL, and a second inorganic encapsulation layer EIL2.

[0226] However, this is merely an example, and the number of inorganic layers and organic layers constituting the encapsulation layer ENC may be changed in various ways.

[0227] In addition, according to embodiments, the capping layer CPL may be located between the encapsulation layer ENC and the second electrode E2 .

[0228] refer to Figure 5 According to an embodiment, the first inorganic encapsulation layer EIL1 may include silicon nitride (SiN x ), silicon oxide (SiO x ) or silicon oxynitride (SiO x N y ) of inorganic insulating materials.

[0229] The organic encapsulation layer EOL disposed on the first inorganic encapsulation layer EIL1 may include an organic material.

[0230] The organic encapsulation layer EOL may include a monomer.

[0231] The second inorganic encapsulation layer EIL2 may be positioned on the organic encapsulation layer EOL.

[0232] The second inorganic encapsulation layer EIL2 may be disposed directly on the organic encapsulation layer EOL.

[0233] The second inorganic encapsulation layer EIL2 may include a first sublayer EIL2a and a second sublayer EIL2b.

[0234] The first sub-layer EIL2 a may be disposed directly over the organic encapsulation layer EOL.

[0235] The second sub-layer EIL2b may be disposed directly on the first sub-layer EIL2a.

[0236] The first sub-layer EIL2a and the second sub-layer EIL2b may include the same inorganic material.

[0237] The first sub-layer EIL2a and the second sub-layer EIL2b may include silicon nitride (SiNx ), silicon oxide (SiO x ) or silicon oxynitride (SiO x N y For example, the first sub-layer EIL2a and the second sub-layer EIL2b may include silicon nitride.

[0238] The first sub-layer EIL2 a according to an embodiment may further include oxygen.

[0239] The oxygen contained in the first sub-layer EIL2a may be oxygen absorbed from external air or moisture penetration.

[0240] The amount of oxygen included in the second sub-layer EIL2b may be smaller than the amount of oxygen included in the first sub-layer EIL2a.

[0241] The first sub-layer EIL2a and the second sub-layer EIL2b may be formed by a deposition process.

[0242] For example, a gas for forming each sub-layer is injected, and the gas may pass through the plasma gas and be deposited.

[0243] In the case of forming the first sub-layer EIL2a and the second sub-layer EIL2b, radio frequency (RF) powers of a chamber power supply for generating the above-mentioned plasma gas may be different.

[0244] For example, RF power used to form the first sub-layer EIL2 a may be less than RF power used to form the second sub-layer EIL2 b .

[0245] For example, the first sub-layer EIL2a may be formed using RF power of 2000 W to 3000 W or less, and the second sub-layer EIL2b may be formed using RF power of 6000 W to 9000 W or less.

[0246] The RF power used to form the first sub-layer EIL2 a may be one-third of the RF power used to form the second sub-layer EIL2 b .

[0247] In addition, the internal pressure of a chamber used in the deposition process of the first sub-layer EIL2 a may be different from the internal pressure of a chamber used in the deposition process of the second sub-layer EIL2 b .

[0248] An internal pressure of a chamber used in a deposition process of the first sub-layer EIL2 a may be greater than an internal pressure of the chamber used in a deposition process of the second sub-layer EIL2 b .

[0249] The internal pressure of the chamber used in the deposition process of the first sub-layer EIL2 a may be about 1.8 Torr or greater.

[0250] An internal pressure of a chamber used in the deposition process of the second sub-layer EIL2 b may be in the range of about 1.5 Torr to about 1.7 Torr.

[0251] Since the first sub-layer EIL2a and the second sub-layer EIL2b are manufactured under different conditions (eg, different RF powers and different gas pressures), the density of the first sub-layer EIL2a and the density of the second sub-layer EIL2b may be different.

[0252] For example, the film density of the second sub-layer EIL2b may be higher than that of the first sub-layer EIL2a.

[0253] For example, the film density of the first sub-layer EIL2a may be 1.8 g / cm 3 or less, and the film density of the second sublayer EIL2b may be 1.99 g / cm 3 Up to 2.0g / cm 3 .

[0254] Due to the density difference, although the first sublayer EIL2a and the second sublayer EIL2b have the same material and the same chemical composition ratio, the refractive indices of the first sublayer EIL2a and the second sublayer EIL2b may be different.

[0255] The refractive index of the first sublayer EIL2a may be about 1.84 or less.

[0256] The first sub-layer EIL 2 a according to an embodiment may include voids therein, and the voids included in the first sub-layer EIL 2 a may be greater than the voids included in the second sub-layer EIL 2 b .

[0257] If the amount of pores included in the first sublayer EIL2a is greater than that in the second sublayer EIL2b, the film density of the first sublayer EIL2a may be reduced, and the film density may be reduced, resulting in improved hygroscopicity.

[0258] The thickness of the first sub-layer EIL2a may be smaller than the thickness of the second sub-layer EIL2b.

[0259] For example, the thickness of the first sub-layer EIL2 a may be in the range of about 800 angstroms to about 1200 angstroms, or in the range of about 800 angstroms to about 1000 angstroms.

[0260] The thickness of the second sub-layer EIL2b may be in the range of about 6000 angstroms to about 7000 angstroms.

[0261] The moisture absorption of the first sub-layer EIL2a (molecules / cm 2 ) may be greater than the moisture absorption amount of the second sub-layer EIL2b.

[0262] For example, the moisture absorption of the first sub-layer EIL2a may be 1×10 15 molecules / cm 2 or larger.

[0263] In addition, in the case of performing reliability evaluation at 85° C. / 85% for 500 hr, the stress in the tensile direction of the first sublayer EIL2 a may be 30 MPa or more.

[0264] The upper surface of the organic encapsulation layer EOL according to an embodiment may include Figure 6 The multiple protrusions shown in .

[0265] An upper surface of the organic encapsulation layer EOL may have an uneven surface.

[0266] The irregularities included in the organic encapsulation layer EOL may refer to protrusions remaining by removing a remaining film in an ashing process of the second inorganic encapsulation layer EIL2 .

[0267] The first sub-layer EIL2 a disposed on the upper surface of the organic encapsulation layer EOL may cover irregularities of the organic encapsulation layer EOL.

[0268] In addition, the upper surface of the first sub-layer EIL2 a may be formed to be uneven and have irregularities.

[0269] In the case where the first and second sub-layers EIL2a and EIL2b are formed on the unevenness of the organic encapsulation layer EOL, steps may occur, seams may occur in some areas, and penetration of external air or moisture may occur through the seams.

[0270] Therefore, external air or moisture may penetrate into the vicinity of the above-mentioned irregularities, pass through the second sub-layer EIL2a and the first sub-layer EIL2a, and reach the second electrode E2.

[0271] The second electrode E2 may be oxidized by external air or moisture, resulting in point defects (eg, gray dark spots (GDS)).

[0272] However, the first sub-layer EIL2a may have a property of absorbing external air or moisture.

[0273] The first sublayer EIL2 a may serve to capture external air or moisture introduced into the second inorganic encapsulation layer EIL2 .

[0274] Therefore, the first sublayer EIL 2 a according to the embodiment may improve the reliability of the display device by blocking a moisture permeation path caused by external air or moisture.

[0275] In addition, the first sub-layer EIL2 a may protect the organic encapsulation layer EOL from being damaged by plasma gas.

[0276] If the first sublayer EIL2a does not protect the surface of the organic encapsulation layer EOL, CO bonds disposed on the surface of the organic encapsulation layer EOL are broken, resulting in oxygen outgassing and dot-like dark spots, and this may reduce the reliability of the display device.

[0277] The second sublayer EIL2b may serve as a barrier to prevent penetration of external air or moisture.

[0278] In the following, reference will be made to Figures 7 to 9 Let's look at examples and comparative examples.

[0279] Figure 7 is a graph showing the moisture absorption according to Examples and Comparative Examples, Figure 8 is an image showing film density according to energy used in a process of forming an inorganic encapsulation layer, and Figure 9 is a graph showing moisture absorption amounts according to Examples and Comparative Examples; this shows moisture absorption amounts according to pressure conditions of the process.

[0280] Will refer to Figure 7 and Table 1 below describe characteristics of the first sub-layer according to Comparative Examples and Examples.

[0281] The comparative example is a case where the first sub-layer is manufactured under a pressure condition of about 1.7 Torr, and the example is a case where the first sub-layer is manufactured under a pressure condition of about 1.8 Torr.

[0282] Other process conditions are the same.

[0283] refer to Figure 7 and Table 1 below, it is determined that in the case of the first sub-layer manufactured according to the example, the film density is reduced and the moisture absorption is increased by about 1.72 times.

[0284] According to the first sublayer manufactured according to the embodiment, oxidation in the second electrode may be prevented by absorbing external air or moisture.

[0285]

Table 1

[0286]

[0287]

[0288] In addition, referring to Table 2, as a result of reliability evaluation under a high temperature and high humidity environment of 85° C. / 85% for 500 hours, 10 point defects (GDS defects) occurred in the comparative example, and no point defect occurred in the example.

[0289]

Table 2

[0290]

[0291] Figure 8 are images of inorganic layers as the deposition energy of the sublayers increases from left to right.

[0292] like Figure 8 As shown in , it can be seen that as power (or energy) is reduced in the deposition process of the first sub-layer and the second sub-layer, the amount of voids included in each layer increases and the film density decreases.

[0293] This is because crystal grains of the inorganic material may not grow sufficiently due to the supply of relatively small energy, and defects or voids may be formed.

[0294] In this manner, in the case where the first sub-layer is formed through a deposition process with relatively low power, it can be seen that the amount of pores included in the sub-layer increases and the characteristic of absorbing external air or moisture is improved.

[0295] refer to Figure 9 , it was determined that as the pressure applied in the process of forming the sub-layer increased, the moisture absorption amount of the sub-layer increased.

[0296] Therefore, according to an embodiment, the thickness of the sublayer is increased, the pressure of the process for manufacturing the sublayer is increased, or the power is reduced to increase the pores contained in the sublayer and improve the hygroscopic properties of external air or moisture, and by improving the display device, a display device that prevents the occurrence of point defects (e.g., GDS) can be provided.

[0297] Although the embodiments have been described in detail above, the scope of the present disclosure is not limited thereto, and various modifications and improvements made by those skilled in the art using the concepts of the present disclosure and as defined in the appended claims are possible within the scope of the present disclosure.

Claims

1. A display device, characterized in that: The display device includes: a transistor disposed on a substrate; a light emitting diode electrically connected to the transistor; a first inorganic encapsulation layer disposed on the light emitting diode; an organic encapsulating layer disposed on the first inorganic encapsulating layer; and a second inorganic encapsulation layer disposed on the organic encapsulation layer, Wherein, the second inorganic encapsulation layer comprises: a first sublayer disposed on the organic encapsulation layer; and a second sublayer arranged on the first sublayer, The density of the first sub-layer is lower than the density of the second sub-layer.

2. The display device according to claim 1, wherein The first sublayer has a thickness in a range of 800 angstroms to 1200 angstroms.

3. The display device according to claim 1, wherein The second sublayer has a thickness in a range of 6000 angstroms to 7000 angstroms.

4. The display device according to claim 1, wherein The moisture absorption capacity of the first sub-layer is greater than that of the second sub-layer.

5. The display device according to claim 1, wherein The amount of voids included in the first sub-layer is greater than the amount of voids included in the second sub-layer.

6. The display device according to claim 1, wherein An upper surface of the organic encapsulation layer includes an uneven surface.

7. The display device according to claim 6, wherein: The first sublayer covers the uneven surface of the upper surface of the organic encapsulation layer, and The upper surface of the first sub-layer includes an uneven surface.

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