Patent ID: 12213365

DETAILED DESCRIPTION

Embodiments of the invention will be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the invention.

To clearly describe the invention, parts that are irrelevant to the description are omitted, and like numerals refer to like or similar constituent elements throughout the specification.

Further, since sizes and thicknesses of constituent members shown in the accompanying drawings are arbitrarily given for better understanding and ease of description, the invention is not limited to the illustrated sizes and thicknesses. In the drawings, the thicknesses of layers, films, panels, regions, etc., are exaggerated for clarity. In the drawings, for better understanding and ease of description, the thicknesses of some layers and areas are exaggerated.

It will be understood that, when an element such as a layer, film, region, or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. Further, in the specification, the word “on” or “above” means disposed on or below the object portion, and does not necessarily mean disposed on the upper side of the object portion based on a gravitational direction.

It will be understood that, although the terms “first,” “second,” “third” etc., may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, “a first element,” “component,” “region,” “layer” or “section” discussed below could be termed a second element, component, region, layer or section without departing from the teachings herein.

In addition, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

Further, in the specification, the phrase “in a plan view” means when an object portion is viewed from above, and the phrase “in a cross-sectional view” means when a cross-section taken by vertically cutting an object portion is viewed from the side.

“About” or “approximately” as used herein 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, considering the measurement in question and the error associated with measurement of the 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.

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

Hereinafter, a display device in an embodiment will be described with reference toFIG.1andFIG.2.

FIG.1illustrates a schematic top plan view of an embodiment of a display device, andFIG.2illustrates a top plan view of an embodiment of a portion including a sensor in a display device.

As illustrated inFIG.1, the display device in the illustrated embodiment includes a substrate100and a pad portion30.

The substrate100includes a display area DA and a non-display area NA. The display area DA is an area in which pixels including a light emitting diode and a transistor display an image thereon, and the non-display area NA is an area in which an image is not displayed. The non-display area NA may surround a periphery of the display area DA. The non-display area NA is an area including the pad portion30in which pads PAD for applying driving signals to pixels are formed or provided.

A plurality of pixels (not illustrated) each including a transistor, a light emitting diode, or the like may be disposed in the display area DA. The pixels may be arranged in various forms, for example, may be arranged in a matrix form. A sensing area TA including a plurality of sensing electrodes520and540inFIG.2may be further disposed above the display area DA to recognize a touch.

In the non-display area NA, a driving voltage line (not illustrated), a driving low voltage line (not illustrated), and the pad portion30may transfer driving signals such as voltages and signals to pixels formed or disposed in the display area DA. In addition, a plurality of sensing wires512and522(refer toFIG.2) may be further disposed in the non-display area NA. The sensing wires512and522may be connected to the sensing electrodes520and540. The sensing wires512and522and the sensing electrodes520and540will be further described below with reference toFIG.2.

The pad portion30is disposed in a portion of the non-display area NA, and includes a plurality of pads PAD. Voltages, signals, etc., may be applied to a plurality of voltage lines (not illustrated) connected to the display area DA through the pads PAD, and the sensing wires512and522(refer toFIG.2). A flexible printed circuit board (“FPCB”) (not illustrated) may be attached to the non-display area NA. The FPCB may be electrically connected to the pad portion30. The FPCB and the pad portion30may be electrically connected by an anisotropic conductive film. The FPCB may include an integrated chip (not illustrated), and a driving signal outputted from the driving integrated circuit may be supplied to each pixel through the pads PAD of the pad portion30.

As illustrated inFIG.2, the substrate100further includes a sensing area TA in which the sensing electrodes520and540are formed or disposed at an upper portion of the display area DA, and a peripheral area PA surrounding the sensing area TA. In an embodiment, the sensing area TA may include the display area DA and a partial area of the non-display area NA ofFIG.1, and the peripheral area PA may include a remaining area excluding the sensing area TA. However, this is merely an example, and positions of the sensing area TA and the peripheral area PA may be variously changed. In an embodiment, the sensing area TA may include a portion of the display area DA, and the peripheral area PA may include a remaining area of the display area DA excluding the sensing region TA, and anon-display area NA, for example. In an alternative embodiment, the sensing area TA may include a display area DA and a non-display area NA.

The sensing area TA may include the sensing electrodes520and540. The sensing electrodes520and540may include a plurality of first sensing electrodes520and a plurality of second sensing electrodes540.

The first sensing electrodes520and the second sensing electrodes540may be electrically separated from each other. In an embodiment, the first sensing electrodes520may be sensing input electrodes, and the second sensing electrodes540may be sensing output electrodes. However, the invention is not limited thereto, and the first sensing electrodes520may be the sensing output electrodes, and the second sensing electrodes540may be the sensing input electrodes.

The first sensing electrodes520and the second sensing electrodes540may be alternately distributed so as to not overlap each other in the sensing area TA, and may be disposed in a mesh form. The first sensing electrodes520may be disposed in plural in a column direction and may be disposed in plural in a row direction, and the second sensing electrode540may also be disposed in plural in the column direction and may be disposed in plural in the row direction. The first sensing electrodes520may be connected to each other in the column direction by a plurality of first sensing electrode connectors521, and the second sensing electrodes540may be connected to each other in the row direction by a plurality of second sensing electrode connectors541.

The first sensing electrodes520and the second sensing electrodes540may be disposed in a same layer. In an embodiment, the first sensing electrodes520and the second sensing electrodes540may be disposed in different layers. The first sensing electrodes520and the second sensing electrodes540may have a rhombus shape, but the invention is not limited thereto. The first sensing electrode520and the second sensing electrode540may have a polygonal shape such as a quadrangle or a hexagon, or a circular or elliptical shape, and may be embodied in various shapes such as having a protrusion to improve sensitivity of a sensor. The first sensing electrodes520and the second sensing electrodes540may be formed or provided as a transparent conductor or an opaque conductor. In an embodiment, the first sensing electrodes520and the second sensing electrodes540may include a transparent conductive oxide (“TCO”), and the TCO may include at least one of an indium tin oxide (“ITO”), an indium zinc oxide (“IZO”), a zinc oxide (ZnO), a carbon nanotube (“CNT”), and graphene, for example. In addition, a plurality of openings may be defined in the first sensing electrodes520and the second sensing electrodes540. The openings defined in the sensing electrodes520and540serve to allow light emitted from a light emitting diode to be emitted to the front without interference.

The first sensing electrodes520may be electrically connected to each other by the first sensing electrode connectors521(also referred to as bridges), and the second sensing electrodes540may be electrically connected to each other by the second sensing electrode connectors541. When the first sensing electrodes520are connected to each other in a first direction, the second sensing electrodes540may be connected to each other in a second direction intersecting the first direction. When the first sensing electrodes520and the second sensing electrodes540are disposed in a same layer, one of the first sensing electrode connectors521and the second sensing electrode connectors541may be disposed at the same layer as that of the first sensing electrodes520and the second sensing electrodes540, and the other one may be disposed at a different layer from that of the first sensing electrodes520and the second sensing electrodes540. As a result, the first sensing electrodes520and the second sensing electrodes540may be electrically separated. The sensing electrode connector disposed in the different layer may be disposed at an upper layer or a lower layer of the first sensing electrodes520and the second sensing electrodes540, and in embodiments described below, descriptions will be made focusing on an embodiment in which the sensing electrode connector is disposed on the lower layer, i.e., a layer closer to the substrate.

The sensing wires512and522are respectively connected to the first sensing electrodes520and the second sensing electrodes540in the peripheral area PA. The sensing wires512and522may include the first sensing wires512and the second sensing wires522. The first sensing wire512may be connected to the second sensing electrodes540disposed in the row direction, and the second sensing wire522may be connected to the first sensing electrodes520disposed in the column direction. In an embodiment, the first sensing wire512and the second sensing wire522may be electrically connected to some of the pads PAD included in the pad portion30ofFIG.1.

InFIG.2, a sensor of a mutual-cap type that senses a touch using two sensing electrodes520and540is illustrated. However, in an embodiment, it may be formed or provided as a sensor of self-cap type that senses a touch using only one sensing electrode.

Hereinafter, a display device in an embodiment will be further described with reference toFIG.3illustrating a cross-sectional view in the display area DA.

FIG.3illustrates a cross-sectional view showing an embodiment of a portion of a display area in a display device.

As illustrated inFIG.3, in the display device in the illustrated embodiment, the display area DA may include a substrate100, a semiconductor layer131, a transistor TFT including a gate electrode124, a source electrode173, and a drain electrode175, a gate insulating layer120, a first inter-insulating layer160, a second inter-insulating layer180, a pixel electrode191, an emission layer370, a bank layer350, a common electrode270, and an encapsulation layer400. Herein, the pixel electrode191, the emission layer370, and the common electrode270may constitute a light emitting diode LED. In addition, the display device further includes the sensing area TA disposed at an upper portion of the display area DA, and the sensing area TA includes a first sensing insulating layer510, the sensing electrodes520and540, and the second sensing electrode connectors541. In addition, the display device may further include a first insulating layer550and a second insulating layer560disposed above the sensing area TA.

The substrate100may include a material having a rigid characteristic such as glass, or a flexible material such as plastic or polyimide that is bendable. A buffer layer111for flattening a surface of the substrate100and blocking penetration of impurity elements may be further disposed on the substrate100. In an embodiment, the buffer layer111may include an inorganic material, and for example, may include an inorganic insulating material such as a silicon nitride (SiNx), a silicon oxide (SiOx), and a silicon oxynitride (SiOxNy). The buffer layer111may have a single layer structure or a multi-layered structure of the material. A barrier layer (not illustrated) may be further disposed on the substrate100. In this case, the barrier layer may be disposed between the substrate100and the buffer layer111. The barrier layer may include an inorganic insulating material such as a silicon nitride (SiNx), a silicon oxide (SiOx), and a silicon oxynitride (SiOxNy). The barrier layer may have a single layer structure or a multi-layered structure of the material.

The semiconductor layer131may be disposed on the substrate100. The semiconductor layer131may include any one of amorphous silicon, polycrystalline silicon, and an oxide semiconductor. In an embodiment, the semiconductor layer131may include low temperature polysilicon (“LTPS”), or may include an oxide semiconductor material including at least one of zinc (Zn), indium (In), gallium (Ga), tin (Sn), and a combination thereof, for example. In an embodiment, the semiconductor layer131may include an indium-gallium-zinc oxide (“IGZO”). The semiconductor layer131may include a channel region, a source region, and a drain region into which it is classified depending on whether or not doped with impurities. The source region and the drain region may have a conductive characteristic corresponding to a conductor.

The gate insulating layer120may cover the semiconductor layer131and the substrate100. In an embodiment, the gate insulating layer120may include an inorganic insulating material such as a silicon nitride (SiNx), a silicon oxide (SiOx), and a silicon oxynitride (SiOxNy). The gate insulating layer120may have a single layer structure or a multi-layered structure of the material.

The gate electrode124may be disposed on the gate insulating layer120. In an embodiment, the gate electrode124may include a metal such as copper (Cu), molybdenum (Mo), aluminum (Al), silver (Ag), chromium (Cr), or tantalum (Ta), or a metal alloy thereof. The gate electrode124may be formed or provided as a single layer or a multilayer. A region of the semiconductor layer131that overlaps the planar gate electrode124may be a channel region.

The first inter-insulating layer160may cover the gate electrode124and the gate insulating layer120. In an embodiment, the first inter-insulating layer160may include an inorganic insulating material such as a silicon nitride (SiNx), a silicon oxide (SiOx), and a silicon oxynitride (SiOxNy). The first inter-insulating layer160may have a single layer structure or a multi-layered structure of the material.

The source electrode173and the drain electrode175are disposed on the first inter-insulating layer160. The source electrode173and the drain electrode175may be connected to the source region and the drain region of the semiconductor layer131through openings defined in the first inter-insulating layer160and the gate insulating layer120, respectively. Accordingly, the semiconductor layer131, the gate electrode124, the source electrode173, and the drain electrode175described above constitute one transistor TFT, e.g., one thin film transistor. In an embodiment, the transistor TFT may include only the source region and the drain region of the semiconductor layer131instead of the source electrode173and the drain electrode175.

In an embodiment, the source electrode173and the drain electrode175may include a metal such as aluminum (Al), copper (Cu), silver (Ag), gold (Au), platinum (Pt), palladium (Pd), nickel (Ni), molybdenum (Mo), tungsten (W), titanium (Ti), chromium (Cr), tantalum (Ta), or the like, or a metal alloy thereof. The source electrode173and the drain electrode175may be formed or provided as a single layer or a multilayer. The source electrode173and the drain electrode175in an embodiment may be configured as a triple layer including an upper layer, an intermediate layer, and a lower layer, the upper layer and the lower layer may include titanium (Ti), and the intermediate layer may include aluminum (Al).

The second inter-insulating layer180may be disposed on the source electrode173and the drain electrode175. The second inter-insulating layer180covers the source electrode173, the drain electrode175, and the first inter-insulating layer160. The second inter-insulating layer180, which is for planarizing a surface of the substrate100provided with the transistor TFT, may be an organic insulating layer, and may include at least one material of a polyimide, a polyamide, an acrylic resin, benzocyclobutene, and a phenol resin.

The pixel electrode191may be disposed on the second inter-insulating layer180. The pixel electrode191is also referred to as an anode, and may be formed or provided as a single layer including a transparent conductive oxide film, a metal material, or as multiple layers including them. In an embodiment, the transparent conductive oxide layer may include an ITO, a poly-ITO, an IZO, an indium gallium zinc oxide (“IGZO”), an indium tin zinc oxide (“ITZO”), or the like. In an embodiment, the metal material may include silver (Ag), molybdenum (Mo), copper (Cu), gold (Au), and aluminum (Al).

A via hole81exposing the drain electrode175may be defined in a second inter-insulating layer180. The drain electrode175and the pixel electrode191may be physically and electrically connected through the via hole81of the second inter-insulating layer180. Accordingly, the pixel electrode191may receive an output current to be transferred from the drain electrode175to the emission layer370.

The bank layer350may be disposed on the pixel electrode191and the second inter-insulating layer180. The bank layer350is also referred to as a pixel defining layer (“PDL”), and a pixel opening351overlapping at least a portion of the pixel electrode191is defined in the bank layer350. In this case, the pixel opening351may overlap a central portion of the pixel electrode191, and may not overlap an edge portion of the pixel electrode191. As a result, a size of the pixel opening351may be smaller than that of the pixel electrode191. The bank layer350may define a formation position of the emission layer370such that the emission layer370may be disposed on a portion thereof where an upper surface of the pixel electrode191is exposed. The bank layer350may be formed or provided as an organic insulator including at least one material of a polyimide, a polyamide, an acryl resin, benzocyclobutene, and a phenol resin. In an embodiment, the bank layer350may be formed or provided as a black pixel define layer (“BPDL”) including a black pigment.

The emission layer370may be disposed within the pixel opening351defined by the bank layer350. The emission layer370may include an organic material that emits light such as red, green, and blue light. The emission layer370emitting red, green, and blue light may include a low molecular weight or high molecular weight organic material. InFIG.3, the emission layer370is illustrated as a single layer, but in practice, an auxiliary layer such as an electron injection layer, an electron transport layer, a hole transport layer, and a hole injection layer may be included above and below the emission layer370, where the hole injection layer and the hole transport layer may be disposed below the emission layer370, and the electron transport layer and the electron injection layer may be disposed above the emission layer370.

The common electrode270may be disposed on the bank layer350and the emission layer370. In an embodiment, the common electrode270may be also referred to as a cathode, and may include a transparent conductive layer including an ITO, an IZO, an IGZO, an ITZO, etc. In addition, the common electrode270may have a translucent characteristic, and in this case, it may constitute a micro-cavity together with the pixel electrode191. According to such a micro-cavity structure, light of a predetermined wavelength is emitted to an upper part by the characteristics and spacing between both of the electrodes, and as a result, red, green, or blue light may be displayed.

The encapsulation layer400may be disposed on the common electrode270. The encapsulation layer400may include at least one inorganic layer and at least one organic layer. In the illustrated embodiment, the encapsulation layer400may include a first inorganic encapsulation layer410, an organic encapsulation layer420, and a second inorganic encapsulation layer430. However, this is merely an example, and numbers of inorganic and organic layers constituting the encapsulation layer400may be variously changed. The first inorganic encapsulation layer410, the organic encapsulation layer420, and the second inorganic encapsulation layer430may be disposed in a portion of the non-display area NA and the display area DA. In an embodiment, the organic encapsulation layer420may be formed or provided around the display area DA, and the first inorganic encapsulation layer410and the second inorganic encapsulation layer430may be formed or provided up to the non-display area NA. The encapsulation layer400, which is for protecting the light emitting diode LED from moisture or oxygen that may be introduced from the outside, may directly contact first ends of the first inorganic encapsulation layer410and the second inorganic encapsulation layer430.

A buffer layer501may be disposed on the encapsulation layer400. The buffer layer501may include an inorganic insulating layer, and an inorganic material included in the inorganic insulating layer may be at least one of a silicon nitride, an aluminum nitride, a zirconium nitride, a titanium nitride, a hafnium nitride, a tantalum nitride, a silicon oxide, an aluminum oxide, a titanium oxide, a tin oxide, a cerium oxide, and a silicon oxynitride. In an embodiment, the buffer layer501may be omitted.

A second sensing electrode connector541, the first sensing insulating layer510, and the plurality of sensing electrodes520and540may be disposed on the buffer layer501. One of the first sensing electrode connectors521and the second sensing electrode connector541may be disposed in a same layer as that of the sensing electrodes520and540, and the other may be disposed at a different layer from that of the sensing electrodes520and540. Hereinafter, an example in which the second sensing electrode connector541is disposed at a different layer from that of the sensing electrodes520and540will be described.

The second sensing electrode connector541, the first sensing insulating layer510, and the sensing electrodes520and540may constitute a sensing sensor. The sensing sensor may be classified into a resistive type, a capacitive type, an electro-magnetic type, and an optical type. The sensing sensor in an embodiment may be a capacitive type of sensor.

The second sensing electrode connector541may be disposed on the buffer layer501, and the first sensing insulating layer510may be disposed on the buffer layer501and the second sensing electrode connector541. The first sensing insulating layer510may include an inorganic insulating material or an organic insulating material. An inorganic insulating material may include at least one of a silicon nitride, an aluminum nitride, a zirconium nitride, a titanium nitride, a hafnium nitride, a tantalum nitride, a silicon oxide, an aluminum oxide, a titanium oxide, a tin oxide, a cerium oxide, and a silicon oxynitride. An organic insulating material may include at least one of an acrylic resin, a methacrylic resin, a polyisoprene, a vinyl resin, an epoxy resin, a urethane resin, a cellulose resin, and a perylene resin.

The sensing electrodes520and540may be disposed on the first sensing insulating layer510. The sensing electrodes520and540may include the first sensing electrodes520and the second sensing electrodes540. The first sensing electrodes520and the second sensing electrodes540may be electrically insulated. An opening exposing an upper surface of the second sensing electrode connector541may be defined in the first sensing insulating layer510, and the second sensing electrode connector541is connected to the second sensing electrodes540through the opening of the first sensing insulating layer510to electrically connect two adjacent second sensing electrodes540. The first sensing electrode connector521connecting the first sensing electrodes520is formed or provided in a same layer as that of the first sensing electrodes520and the second sensing electrodes540.

The sensing electrodes520and540may include a conductive material having good conductivity. In an embodiment, the sensing electrodes520and540may include a metal such as aluminum (Al), copper (Cu), silver (Ag), gold (Au), platinum (Pt), palladium (Pd), nickel (Ni), molybdenum (Mo), tungsten (W), titanium (Ti), chromium (Cr), tantalum (Ta), or the like, or a metal alloy thereof, for example. The sensing electrodes520and540may be configured as a single layer or a multilayer. In this case, an opening may be defined in the sensing electrodes520and540so that light emitted from the light emitting diode is emitted upward without interference. In an embodiment, the sensing electrodes520and540may be configured as a triple layer including an upper layer, an intermediate layer, and a lower layer, where the upper layer and the lower layer may include titanium (Ti), and the intermediate layer may include aluminum (Al).

A second sensing insulating layer530may be disposed on the sensing electrodes520and540and the first sensing insulating layer510. The second sensing insulating layer530may include an inorganic insulating material or an organic insulating material. In an embodiment, an inorganic insulating material may include at least one of a silicon nitride, an aluminum nitride, a zirconium nitride, a titanium nitride, a hafnium nitride, a tantalum nitride, a silicon oxide, an aluminum oxide, a titanium oxide, a tin oxide, a cerium oxide, and a silicon oxynitride. In an embodiment, an organic insulating material may include at least one of an acrylic resin, a methacrylic resin, a polyisoprene, a vinyl resin, an epoxy resin, a urethane resin, a cellulose resin, and a perylene resin.

A first insulating layer550is disposed on the second sensing insulating layer530. The first insulating layer550may include a light-transmitting organic insulating material having a low refractive index. In an embodiment, the first insulating layer550may include at least one of an acrylic resin, a polyimide resin, a polyamide resin, and Alq3[Tris(8-hydroxyquinolinato)aluminum], for example. The first insulating layer550may have a relatively smaller refractive index than that of a second insulating layer560to be described later. In an embodiment, the first insulating layer550may have a refractive index of about 1.40 to about 1.59, for example.

An opening551is defined in the first insulating layer550. The opening551refers to a portion where the second sensing insulating layer530is not covered by the first insulating layer550. The opening551of the first insulating layer550may overlap the pixel opening351.

A distance S1between the pixel opening351and the opening551of the first insulating layer550indicates a shortest distance between an edge of the pixel opening351and an edge of the opening551. The edge of the pixel opening351refers to a point where an edge of the bank layer350contacts the pixel electrode191. The edge of the opening551refers to a point where the edge of the first insulating layer550contacts the second sensing insulating layer530.

The second insulating layer560may be disposed on the second sensing insulating layer530and the first insulating layer550. The second insulating layer560may include a light-transmitting organic insulating material having a high refractive index. The second insulating layer560may have a relatively larger refractive index than that of the first insulating layer550. In an embodiment, the second insulating layer560may have a refractive index of about 1.60 to about 1.80, for example.

The second insulating layer560may be disposed within the opening551of the first insulating layer550. In this case, the second insulating layer560is in contact with a side surface of the first insulating layer550. Furthermore, the second insulating layer560may also be disposed on an upper surface of the first insulating layer550so as to contact the upper surface of the first insulating layer550.

Although not illustrated, a polarization layer including a linear polarizer and a retarder may be further disposed on the sensing area TA. In addition, a cover window for protecting the sensing area TA and the display area DA may be further disposed on the sensing area TA. In this case, an adhesive layer may be further disposed between the polarization layer and the cover window.

The sensing area TA may include the first insulating layer550, in which the opening551is defined, and the second insulating layer560disposed in the opening551of the first insulating layer550, thereby improving front visibility and light emission efficiency of the display device. That is, at least a portion of the light generated from the light emitting diode LED may be totally reflected at an interface between the first insulating layer550and the second insulating layer560, thereby condensing light to the front.

Light L generated from the emission layer370may be emitted in various directions, and enters the sensing area TA with various incident angles. In this case, at least some of the light L incident on the second insulating layer560of the sensing area TA is reflected at the interface between the first insulating layer550and the second insulating layer560. In particular, when an incident angle of the light L incident on the second insulating layer560is greater than a critical angle, the incident light L may be totally reflected at the interface between the first insulating layer550and the second insulating layer560. That is, the light L that is incident on the second insulating layer560having a relatively large refractive index may travel to the first insulating layer550having a relatively small refractive index, and may be totally reflected at the interface between the first insulating layer550and the second insulating layer560.

In this case, the interface between the first insulating layer550and the second insulating layer560may form a straight line parallel to the substrate100at a predetermined angle. The interface between the first insulating layer550and the second insulating layer560may be a side surface of the first insulating layer550. Accordingly, the side surface of the first insulating layer550may be inclined at a predetermined inclination angle θ with respect to the upper surface of the second sensing insulating layer530. That is, the side inclination angle θ of the first insulating layer550refers to an angle defined by the side surface of the first insulating layer550with respect to the upper surface of the second sensing insulating layer530in the opening551of the first insulating layer550.

In the display device in an embodiment, the side inclination angle θ of the first insulating layer550in the opening551of the first insulating layer550may be different depending on a position. Hereinafter, the inclination angle θ of the side surface of the first insulating layer550depending on a position of the opening551of the first insulating layer550will be described with reference toFIG.4toFIG.6.

FIG.4partially illustrates a top plan view of an embodiment of a display device,FIG.5illustrates a cross-sectional view taken along line V-V ofFIG.4, andFIG.6illustrates a cross-sectional view taken along line VI-VI ofFIG.4.FIG.4illustrates an embodiment of a pixel opening and an opening of the first insulating layer of the display device.FIG.5andFIG.6illustrate an embodiment of some layers of a display device.FIG.5andFIG.6illustrate an embodiment of the pixel electrode191and layers disposed thereon. That is, layers disposed under the pixel electrode191are omitted.

As illustrated inFIG.4, the opening551of the first insulating layer550of the display device in an embodiment may have a substantially polygonal shape in a plan view.

In an embodiment, the opening551of the first insulating layer550may have a quadrangular shape in a plan view, for example. In this case, the opening551of the first insulating layer550may have a polygonal shape with a corner portion chamfered in a plan view. The corner portion of the opening551of the first insulating layer550may be chamfered in a straight line or a curved line. However, the planar shape of the opening551of the first insulating layer550is not limited thereto, and may be variously changed. In an embodiment, the opening551of the first insulating layer550may have a circular shape or an oval shape, for example.

An edge of the opening551of the first insulating layer550may include a first region R1and a second region R2in a plan view. The first region R1may be a corner portion of the polygonal shape defining the opening551of the first insulating layer550, and the second region R2may be a portion other than the first region R1. A ratio of the first region R1to the second region R2at the edge of the opening551of the first insulating layer550may be less than 1.

As illustrated inFIG.5andFIG.6, the side inclination angle θ1of the first insulating layer550in the first region R1may be different from a side inclination angle θ2of the first insulating layer550in the second region R2.FIG.5illustrates the side inclination angle θ1of the first insulating layer550in the first region R1, andFIG.6illustrates the side inclination angle θ2of the first insulating layer550in the second region R2.

The side inclination angle θ1of the first insulating layer550in the first region R1may be smaller than the side inclination angle θ2of the first insulating layer550in the second region R2. In an embodiment, the side inclination angle θ1of the first insulating layer550in the first region R1may be lower by 20 degrees or more than the side inclination angle θ2of the first insulating layer550in the second region R2, for example. In the first region R1, the side inclination angle θ1of the first insulating layer550may be designed to be about 50 degrees, and in the second region R2, the side inclination angle θ2of the first insulating layer550may be designed to be about 70 degrees. In this case, assuming that a process error is at most 20 degrees, the side inclination angle θ1of the first insulating layer550in the first region R1may be about 30 degrees or more and about 70 degrees or less. The side inclination angle θ1of the first insulating layer550in the first region R1may be about 30 degrees or less. In addition, in the second region R2, the side inclination angle θ2of the first insulating layer550may be about 50 degrees or more and about 90 degrees or less.

The opening551of the first insulating layer550may overlap the pixel opening351. A planar shape of the pixel opening351may be similar to that of the opening551of the first insulating layer550. The pixel opening351may have a substantially polygonal shape in a plan view. The pixel opening351may be defined inside the opening551of the first insulating layer550in a plan view. That is, the size of the opening551of the first insulating layer550may be larger than that of the pixel opening351.

The distance S1between the pixel opening351and the opening551of the first insulating layer550in the first region R1may be different from a distance S2between the pixel opening351and the opening551of the first insulating layer550in the second region R2. In an embodiment, the distance S1between the pixel opening351and the opening551of the first insulating layer550in the first region R1may be larger than the distance S2between the pixel opening351and the opening551of the first insulating layer550in the second region R2, for example. However, the invention is not limited thereto, and the distance S1between the pixel opening351and the opening551of the first insulating layer550in the first region R1may be the same as the distance S2between the pixel opening351and the opening551of the first insulating layer550in the second region R2.

Hereinafter, an effect of forming the side inclination angle θ of the first insulating layer550differently depending on the position will be described with further reference toFIG.7toFIG.9.

FIG.7illustrates fluidity of a material depending on an angle of a pattern when a predetermined material is applied onto a predetermined pattern.FIG.8illustrates an opening of a first insulating layer in a reference example of a display device, andFIG.9illustrates an embodiment of an opening of a first insulating layer in a display device. InFIG.8andFIG.9, a movement path of a material for forming a second insulating layer around an opening of the first insulating layer is illustrated.

As illustrated inFIG.7, when a predetermined material is applied onto a predetermined pattern having an inclination angle α of about 0 degree, i.e., no inclination angle, the material may be smoothly spread. An initial angle at a point where a droplet is dropped is about 65 degrees, and it may be seen that it spreads smoothly from the point where the droplet is dropped. It may be seen that, when a predetermined material is applied onto a predetermined pattern having an inclination angle α of about 10 degrees, fluidity of the material is lowered compared to the case of about 0 degree. That is, the material applied onto the pattern moves to a point of the inclined portion, and then stops. When the inclination angle α of the predetermined pattern is more than about 20 degrees, the fluidity of the material is further lowered, so that the material applied onto the pattern cannot enter the inclined portion. That is, when the inclination angle α of the pattern is increased, the fluidity of the material applied onto the pattern may be lowered, thereby preventing the material from entering the inclined portion.

In the reference example of the display device, the side inclination angle of the first insulating layer may be constant, and in this case, the side inclination angle may be about 70 degrees or more. After the first insulating layer is formed or provided, a material for forming the second insulating layer may be applied to form the second insulating layer thereon. In this case, the material for forming the second insulating layer applied onto the first insulating layer may move in various directions. As illustrated inFIG.8, in the reference example of the display device, the material for forming the second insulating layer may not enter the opening551of the first insulating layer due to a high side inclination of the first insulating layer. The first insulating layer may include a plurality of openings551, and the material for forming the second insulating layer may not be disposed in some of the openings551. Accordingly, in the reference example of the display device, the second insulating layer may not be entirely uniformly formed or disposed on the substrate. In this case, a method of thickly forming the second insulating layer may be considered in order to uniformly form the second insulating layer, and as a result, a thickness of the display device may be increased. In addition, other problems may occur in a post-process, and when applied to a foldable product, there are problems such as deterioration of impact resistance.

In the display device in the embodiment, the material for forming the second insulating layer may smoothly enter the opening551of the first insulating layer by forming a relatively low side inclination angle of the first insulating layer in the first region R1. That is, the movement path of the material for forming the second insulating layer may be formed or provided by the low inclination angle of the first insulating layer in the first region R1. The openings551may be defined in the first insulating layer, and the material for forming the second insulating layer may be entirely disposed in the openings551. Accordingly, in the display device in the embodiment, the second insulating layer may be uniformly formed or provided with a thin thickness. Accordingly, an overall thickness of the display device may be reduced, problems occurring in post-processing may be solved, and it may be stably used for foldable products.

In addition, in the display device in the embodiment, light that is incident on the interface between the first insulating layer and the second insulating layer may be totally reflected and condensed to the front of the display device by forming a relatively high side inclination angle of the first insulating layer in the second region R2. That is, it is possible to improve light emission efficiency at the front of the display device.

In this case, a ratio of the first region R1to the second region R2at an edge of the openings551of the first insulating layer may be variously changed. In this case, the ratio of the first region R1to the second region R2may be less than 1. When the ratio of the first region R1to the second region R2is set too low, the movement path of the material for forming the second insulating layer may be reduced, so that uniform formation of the second insulating layer may be difficult. When the ratio of the first region R1to the second region R2is set too high, the light emission efficiency of the front of the display device may be relatively lowered. Accordingly, the ratio of the first region R1to the second region R2may be appropriately selected so as to increase the front emission efficiency of the display device while uniformly forming the second insulating layer. In an embodiment, the ratio of the first region R1to the second region R2may be about 1% or more and about 20% or less, for example.

Hereinafter, a photomask for defining an opening of a first insulating layer of a display device in an embodiment will be described with reference toFIG.10toFIG.21.

FIG.10toFIG.21illustrate top plan views showing various embodiments of a photomask for defining an opening in a first insulating layer of a display device.

The first insulating layer of the display device in the embodiment may include a negative type of photosensitive material. First, the material for forming the first insulating layer is entirely applied, and after the photomask is matched, an exposure process is performed. In this case, a portion exposed to light remains in the first insulating layer, and a portion masked by a pattern of the photomask is removed to define an opening. However, the invention is not limited thereto, and the first insulating layer of the display device in the embodiment may include a positive type of photosensitive material. In this case, the pattern of the photomask for defining the opening of the first insulating layer may be reversely formed or provided.

As illustrated inFIG.10, a photomask900for defining an opening of a first insulating layer of a display device in an embodiment may include a center pattern910having a substantially polygonal shape and a peripheral pattern920disposed adjacent to a corner portion of the center pattern910.

The center pattern910may have a polygonal shape, e.g., a quadrangular shape. In this case, the corner portion of the center pattern910may be chamfered in a straight line or a curved line.

The peripheral pattern920may be disposed at each corner portion of the center pattern910. When the center pattern910has the quadrangular shape, the peripheral pattern920may be disposed at each of the four corner portions of the center pattern910. That is, four peripheral patterns920may be disposed adjacent to one center pattern910.

The peripheral patterns920may be formed or provided in a form in which a plurality of rod shapes is arranged side by side. In this case, a length of the rods may gradually increase as they move away from the center pattern910. A width of the rods may be constant.

As illustrated inFIG.11toFIG.21, the photomask900for defining the opening of the first insulating layer of the display device in the embodiment may include the center pattern910and the peripheral pattern920. A shape of the center pattern910in the photomask900illustrated inFIG.11toFIG.21is substantially the same as that of the photomask illustrated inFIG.10, and a shape of the peripheral pattern920may be different from that of the photomask illustrated inFIG.10. Hereinafter, various shapes of the peripheral pattern920will be described.

As illustrated inFIG.11, the peripheral pattern920of the photomask900for defining the opening of the first insulating layer of the display device in the embodiment may be formed or provided in a form in which a plurality of rod shapes is arranged side by side. In this case, the rods may have a constant length. A width of the rods may be constant.

As illustrated inFIG.12, the peripheral pattern920of the photomask900for defining the opening of the first insulating layer of the display device in the embodiment may be formed or provided in a form in which a plurality of rod shapes is arranged side by side. In this case, a length of the rods may gradually increase as they move away from the center pattern910. A width of the rods may be constant. A distance between adjacent rods may gradually increase as a distance from the center pattern910increases.

As illustrated inFIG.13, the peripheral pattern920of the photomask900for defining the opening of the first insulating layer of the display device in the embodiment may be formed or provided in a form in which a plurality of rod shapes is arranged side by side. In this case, the rods may have a constant length. A width of the rods may be constant. A distance between adjacent rods may gradually increase as a distance from the center pattern910increases.

As illustrated inFIG.14, the peripheral pattern920of the photomask900for defining the opening of the first insulating layer of the display device in the embodiment may be formed or provided in a form in which a plurality of rod shapes is arranged side by side. In this case, a length of the rods may gradually increase as they move away from the center pattern910. A width of the rods may gradually decrease as they move away from the center pattern910. A distance between adjacent rods may increase as the distance from the center pattern910increases.

As illustrated inFIG.15, the peripheral pattern920of the photomask900for defining the opening of the first insulating layer of the display device in the embodiment may be formed or provided in a form in which a plurality of rod shapes is arranged side by side. In this case, the rods may have a constant length. A width of the rods may decrease as the distance from the center pattern910increases. A distance between adjacent rods may increase as the distance from the center pattern910increases.

As illustrated inFIG.16, the peripheral pattern920of the photomask900for defining the opening of the first insulating layer of the display device in the embodiment may be formed or provided in a form in which a plurality of rod shapes is arranged side by side. In this case, the rod shape may be formed or provided in a shape that is bent at least once. A length of the rods may be constant. A width of the rods may be constant. A distance between adjacent rods may increase as the distance from the center pattern910increases.

As illustrated inFIG.17, the peripheral pattern920of the photomask900for defining the opening of the first insulating layer of the display device in the embodiment may be formed or provided in a form in which a plurality of rod shapes is arranged side by side. In this case, the rods may extend in a direction that is perpendicular to the corner portion of the center pattern910. The length of the rods may be constant, and the width of the rods may be constant.

As illustrated inFIG.18, the peripheral pattern920of the photomask900for defining the opening of the first insulating layer of the display device in the embodiment may be formed or provided in a form in which a plurality of rod shapes is arranged to have a fan shape. In this case, a first end of the rods is gathered at a point that is adjacent to the corner portion of the center pattern910, and a second end of the rods is spaced apart at a predetermined interval. A length and a width of the rods may be constant.

As illustrated inFIG.19, the peripheral pattern920of the photomask900for defining the opening of the first insulating layer of the display device in the embodiment may have a rod shape. In this case, one rod shape may be disposed so as to be adjacent to each corner portion of the center pattern910. The rods may extend in a direction that is perpendicular to the corner portion of the center pattern910.

As illustrated inFIG.20, the peripheral pattern920of the photomask900for defining the opening of the first insulating layer of the display device in the embodiment may be formed or provided in a form in which a plurality of quadrangles has a triangular shape. In this case, a number of quadrangles may increase as the distance from the corner portion of the center pattern910increases.

As illustrated inFIG.21, the peripheral pattern920of the photomask900for defining the opening of the first insulating layer of the display device in the embodiment may have a trapezoid shape. In this case, the peripheral pattern920may gradually have a wider width as the distance from the center pattern910increases. In this case, the center pattern910may be a full-tone pattern, and the peripheral pattern920may be a half-tone pattern.

The opening of the first insulating layer of the display device in an embodiment may be defined by various photomasks900as illustrated inFIG.10toFIG.21. In this case, an opening corresponding to the shape of the substantially center pattern910may be defined, and the opening may have relatively low inclination.

Next, a display device in an embodiment will be described with reference toFIG.22.

Since the display device in the embodiment illustrated inFIG.22is substantially the same as the display device in the embodiment shown inFIG.1toFIG.6, a description of the same parts will be omitted. In the illustrated embodiment, the positions of the first region and the second region are different from those of the previous embodiment, and this will be further described below.

FIG.22partially illustrates a top plan view of a display device.FIG.22illustrates a pixel opening and an opening of the first insulating layer of the display device.

As illustrated inFIG.22, the opening551of the first insulating layer of the display device in an embodiment may have a substantially polygonal shape in a plan view. In an embodiment, the opening551of the first insulating layer may be defined in a quadrangular shape, and each corner portion of the quadrangle may be chamfered in a straight line or a curved line, for example.

An edge of the opening551of the first insulating layer may include a first region R1and a second region R2in a plan view. The first region R1may be a central portion of each side of a quadrangle defining the opening551of the first insulating layer550, and the second region R2may be a portion other than the first region R1. The second region R2may include each corner portion of the quadrangle defining the opening551of the first insulating layer and a periphery thereof. In this case, the ratio of the first region R1to the second region R2may be less than 1.

A side inclination angle of the first insulating layer in the first region R1may be smaller than a side inclination angle of the first insulating layer in the second region R2. In the previous embodiment, the first region R1may be disposed at each corner portion of the quadrangle, and in the illustrated embodiment, the first region R1may be disposed at a central portion of each side of the quadrangle.

Since the side inclination angle of the first insulating layer in the first region R1is relatively low, the light emission efficiency toward the front in the first region R1may be relatively low. In the previous embodiment, a corner portion having a relatively far distance between the pixel opening351and the opening551of the first insulating layer may be set as the first region R1, thereby minimizing a decrease in light emission efficiency. When the distance between the pixel opening351and the opening551of the first insulating layer is substantially the same in all regions, a position of the first region R1may not significantly affect the light emission efficiency. Accordingly, the position of the first region R1may be variously changed. In an embodiment, as in the illustrated embodiment, the first region R1may be disposed at the central portion of each side of the quadrangle defining the opening551of the first insulating layer, or may be disposed at a point that is inclined to one side from the central portion, for example.

Next, a display device in an embodiment will be described with reference to FIG.23andFIG.24.

Since the display device in the embodiment illustrated inFIG.23andFIG.24is substantially the same as the display device in the embodiment shown inFIG.1toFIG.6, a description of the same parts will be omitted. The illustrated embodiment differs from the previous embodiment in that the inclination of the side surface of the first insulating layer is made in a stepped shape, and will be further described below.

FIG.23andFIG.24illustrate an embodiment of some layers of a display device. As illustrated inFIG.23andFIG.24, the side inclination angle θ1of the first insulating layer550in the first region R1may be different from a side inclination angle θ2of the first insulating layer550in the second region R2. The side inclination angle θ1of the first insulating layer550in the first region R1may be smaller than the side inclination angle θ2of the first insulating layer550in the second region R2.FIG.23illustrates the side inclination angle θ1of the first insulating layer550in the first region R1, andFIG.24illustrates the side inclination angle θ2of the first insulating layer550in the second region R2.

In the previous embodiment, the inclination of the side surface of the first insulating layer550may be formed or provided in a continuous straight line or curved shape. In the illustrated embodiment, the inclination of the side surface of the first insulating layer550may have a step shape. When the inclination of the side surface of the first insulating layer550has the step shape, the inclination angle of the side surface of the first insulating layer550may be an angle defined between a virtual line connecting successively disposed steps and an upper surface of the second sensing insulating layer530.

The shape of the inclined portion of the side surface of the first insulating layer550is not limited thereto, and the shape of the photomask for patterning the first insulating layer550, an exposure amount, an exposure time, a material constituting the first insulating layer550, a type of developer, or the like may be variously changed.

Next, a display device in an embodiment will be described with reference toFIG.25toFIG.27.

Since the display device in the embodiment illustrated inFIG.25toFIG.27is substantially the same as the display device in the embodiment shown inFIG.1toFIG.6, a description of the same parts will be omitted. The illustrated embodiment differs from the previous embodiment in that the inclination of the side surface of the bank layer is different depending on a position thereof, and will be further described below.

FIG.25partially illustrates a top plan view of an embodiment of a display device in an embodiment,FIG.26illustrates a cross-sectional view taken along line XXVI-XXVI ofFIG.25, andFIG.27illustrates a cross-sectional view taken along line XXVII-XXVII ofFIG.25.FIG.25illustrates an embodiment of a pixel opening and an opening of the first insulating layer of the display device.FIG.26andFIG.27illustrate an embodiment of some layers of a display device.

As illustrated inFIG.25, the pixel opening351of the display device in the embodiment may have a substantially polygonal shape in a plan view. In an embodiment, the pixel opening351may have a quadrangular shape in a plan view, for example. In this case, the pixel opening351may have a polygonal shape having a chamfered corner in a plan view. In this case, the corner portion of the pixel opening351may be chamfered in a straight line or a curved line. However, the planar shape of the pixel opening351is not limited thereto, and may be variously changed. In an embodiment, the pixel opening351may have a circular shape or an oval shape, for example.

An edge of the pixel opening351may include a first region R11and a second region R22in a plan view. The first region R11may be a corner portion of the polygonal shape forming the pixel opening351, and the second region R22may be a portion other than the first region R11. A ratio of the first region R11to the second region R22at the edge of the pixel opening351may be less than 1.

As illustrated inFIG.26andFIG.27, a side inclination angle θ11of the bank layer350in the first region R11may be different from a side inclination angle θ22of the bank layer350in the second region R2.FIG.26illustrates the side inclination angle θ11of the bank layer350in the first region R1, andFIG.27illustrates the side inclination angle θ22of the bank layer350in the second region R2.

The side inclination angle θ11of the bank layer350in the first region R11may be smaller than the side inclination angle θ22of the bank layer350in the second region R2. In an embodiment, the side inclination angle θ11of the bank layer350in the first region R11may be lower by 20 degrees or more than the side inclination angle θ22of the bank layer350in the second region R22, for example. In the first region R11, the side inclination angle θ11of the bank layer350may be designed to be about 50 degrees, and in the second region R22, the side inclination angle θ22of the bank layer350may be designed to be about 70 degrees. In this case, assuming that a process error is at most 20 degrees, the side inclination angle θ11of the bank layer350in the first region R11may be about 30 degrees or more and about 70 degrees or less. The side inclination angle θ11of the bank layer350in the first region R11may be about 30 degrees or less. In addition, in the second region R22, the side inclination angle θ22of the bank layer350may be about 50 degrees or more and about 90 degrees or less.

The encapsulation layer400may be formed or disposed on the bank layer350, and the encapsulation layer400may include an organic encapsulation layer420. The side surface of the bank layer350has a constant inclination angle, and in the case of having a high inclination angle, the material for forming the organic encapsulation layer420may not enter the pixel opening351of the bank layer350.

In the display device in the embodiment, the material for forming the bank layer350may smoothly enter the pixel opening351of the bank layer350by forming a relatively low side inclination angle of the bank layer350in the first region R11. That is, a movement path of the material for forming the encapsulation layer may be formed or provided by the low inclination angle of the bank layer350in the first region R11. A plurality of pixel openings351may be defined in the bank layer350, and the material for forming the encapsulation layer may be entirely disposed in the pixel openings351. Accordingly, in the display device in an embodiment, the encapsulation layer may be uniformly formed or provided with a thin thickness. Accordingly, an overall thickness of the display device may be reduced, problems occurring in post-processing may be solved, and it may be stably used for foldable products.

In the display device in an embodiment, the side inclination angle θ of the first insulating layer550in the opening551of the first insulating layer550may be constant. However, the invention is not limited thereto, and the side inclination angle of the first insulating layer550in the opening551of the first insulating layer550may be different according to a position.

While this invention has been described in connection with what is presently considered to be practical embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention.