Patent ID: 12211870

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present invention will now be described more fully hereinafter with reference to the accompanying drawings. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein.

It will also be understood that when a layer is referred to as being “on” another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. The same reference numbers indicate the same components throughout the specification, and thus, repetitive descriptions may be omitted. In the attached figures, the thickness of layers and regions is exaggerated for clarity. In other words, since sizes and thicknesses of components in the drawings may be exaggerated for clarity, the following embodiments of the present invention are not limited thereto.

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 may be used to distinguish one element from another element. For example, a first element discussed below may be termed a second element without departing from the spirit and scope of the present invention. The description of an element as a “first” element may not require or imply the presence of a second element or other elements. The terms “first”, “second”, etc. may also be used herein to differentiate different categories or sets of elements. For example, for conciseness, the terms “first”, “second”, etc. may represent “first-category (or first-set)”, “second-category (or second-set)”, etc., respectively.

Hereinafter, embodiments of the present invention will be described with reference to the attached drawings.

FIG.1is a perspective view of a display device according to an embodiment of the present invention.

Referring toFIG.1, a display device10, which is a device for displaying a moving image or a still image, may be used as a display screen of various products such as televisions, notebooks, monitors, billboards, internet of things (IOTs) as well as portable electronic appliances such as mobile phones, smart phones, tablet personal computers (tablet PCs), smart watches, watch phones, mobile communication terminals, electronic notebooks, electronic books, portable multimedia players (PMPs), navigators, and ultra mobile PCs (UMPCs).

The display device10includes a display panel100, a display driving circuit200, a circuit board300, and a fingerprint sensor400.

The display panel100may be a light-emitting display panel such as an organic light-emitting display panel using an organic light-emitting diode, a quantum dot light-emitting display panel including a quantum dot light-emitting layer, an inorganic light-emitting display panel including an inorganic semiconductor, or a micro light-emitting display panel using a micro light-emitting diode (LED). Hereinafter, the display panel10will be mainly described as an organic light-emitting display panel, but the present invention is not limited thereto. For example, in an embodiment of the present invention, as the display panel10, other types of display panels such as a liquid crystal display panel, a quantum dot liquid crystal display panel, a quantum nano light-emitting display panel (nano NED), and a micro LED may be applied.

The display panel100may include a display area DA, in which an image is displayed, and a non-display area NDA, in which no image is displayed. The non-display area NDA may be disposed to at least partially surround the display area DA. The non-display area NDA may form a bezel.

The display area DA may have a polygonal shape. For example, the display area DA may have a rectangular shape having right-angled corners or rounded corners on the plane. However, the planar shape of the display area DA is not limited to a rectangular shape, and for example, may be formed in a circular shape, an elliptical shape, and other various shapes.

In the drawings, for example, short sides of the rectangle of the display area DA extend in the first direction DR1and long sides thereof extend in the second direction DR2perpendicular to the first direction DR1. The third direction DR3is a direction substantially perpendicular to the first direction DR1and the second direction DR2and may be substantially the same as the thickness direction of the display device10.

The display area DA may include a plurality of pixels. The pixels may be arranged in a matrix shape. Each of the pixels may include a light-emitting layer and a circuit layer controlling the amount of light emitted from the light-emitting layer. The circuit layer may include, for example, a wiring, an electrode, and at least one transistor. The light-emitting layer may include an organic light-emitting material. For example, the light-emitting layer may be sealed by an encapsulation film.

The display area DA may include a fingerprint sensing area FSA. The fingerprint sensing area FSA may be disposed in the display area DA. A user's fingerprint may be sensed in the fingerprint sensing area FSA. The fingerprint sensor400for sensing the user's fingerprint may be disposed in the fingerprint sensing area FSA. The fingerprint sensing area FSA may be located in a part of the display area DA, but the present invention is not limited thereto. For example, the fingerprint sensing area FSA may be substantially the same as the display area DA, and may overlap the entire display area DA.

For example, the non-display area NDA may surround all sides of the display area DA, and may form a frame of the display area DA. However, the present invention is not limited thereto.

The display panel100may be flexible such that it can be, for example, warped, curved, bent, folded, or rolled. However, the present invention is not limited thereto.

The display panel100may include a main area MA and a sub-area SBA.

A display area DA, a non-display area NDA, and a fingerprint sensing area FSA may be located in the main area MA. For example, the main area MA may have a shape similar to the planar shape of the display device1. For example, the main area MA may be a flat area located on one plane. However, the present invention is not limited thereto, and for example, at least one of the edges other than the edges (sides) connected to a bending area in the main area MA may be bent to form a curved surface or may be bent in a vertical direction.

The sub-area SBA may protrude in the second direction DR2from one side of the main area MA. The length of the sub-area SBA in the first direction DR1may be smaller than the length of the main area MA the first direction DR1, and the length of the sub-area SBA in the second direction DR2may be smaller than the length of the main area MA in the second direction DR2, but the present invention is not limited thereto.

Although it is illustrated in the drawings that the sub-area SBA is unfolded, the sub-area SBA may be bent. For example, the sub-area SBA may be bent with a curvature in a direction opposite to the display surface to, for example, overlap the lower surface of the main area MA. In this case, the surface of the sub-area SBA is reversed, and at least a part of the sub-area SBA may be disposed on the lower surface of the display panel100. For example, when the sub-area SBA is bent, the sub-area SBA may overlap the main area MA in the thickness direction. The display driving circuit200may be disposed in the sub-area SBA.

The display driving circuit200may generate signals and voltages for driving the display panel100. The display driving circuit200may be formed as an integrated circuit (IC), and attached onto the display panel100by, for example, a chip on glass (COG) method, a chip on plastic (COP) method, or an ultrasonic bonding method, but the present invention is not limited thereto. For example, the display driving circuit200may be attached onto the circuit board300in a chip on film (COF) method.

The circuit board300may be attached to one end of the sub-area SBA of the display panel100by using an anisotropic conductive film or ultrasonic bonding. Through this, the circuit board300may be electrically connected to the display panel100and the display driving circuit200. The display panel100and the display driving circuit200may receive digital video data, timing signals, and driving voltages through the circuit board300. For example, the circuit board300may be a flexible printed circuit board, a printed circuit board, or a flexible film such as a chip on film.

The fingerprint sensor400may be disposed on the lower surface of the display panel100. The fingerprint sensor400may be disposed within the display area DA. For example, the fingerprint sensor400may be disposed in the fingerprint sensing area FSA disposed in the display area DA. The fingerprint sensor400may be attached to the lower surface of the display panel100using an adhesive member (STM, refer toFIG.4).

FIG.2is a perspective view of a fingerprint sensor according to an embodiment of the present invention.

Referring toFIG.2, the fingerprint sensor400may include a fingerprint sensor substrate FSUB, a light sensing layer410, an optical layer420, a flexible film430, a sensor circuit board440, and a sensor driving circuit450.

Components may be disposed on the fingerprint sensor substrate FSUB. For example, the fingerprint sensor substrate FSUB may support components disposed thereon. For example, the fingerprint sensor substrate FSUB may include an insulating material such as glass or polymer resin. For example, the fingerprint sensor substrate FSUB may include polyimide. The fingerprint sensor substrates FSUB may be a flexible substrate capable of bending, folding, rolling, or the like.

The light sensing layer410may be disposed on the fingerprint sensor substrate FSUB. The light sensing layer410may include a plurality of sensor pixels SP (refer toFIG.3) arranged in the first direction DR1and the second direction DR2. Each of the sensor pixels SP (refer toFIG.3) may include a light sensing element through which a sensing current flows according to incident light and at least one transistor connected to the light sensing element. The light sensing element may include a photo diode or a photo transistor.

The optical layer420may be disposed on the light sensing layer410. An infrared filter layer may be disposed on the optical layer420, or an infrared filter layer may be disposed between the optical layer420and the light sensing layer410.

The optical layer420may include a first area and a second area having different light transmittances from each other. The light transmittance of the first area may be greater than that of the second area. In an embodiment of the present invention, the first area (hereinafter, referred to as a light transmitting area OA) may be a light transmitting area OA that transmits light, and the second area (hereinafter, referred to as a light blocking area LSA) may be a light blocking area LSA that blocks light. Hereinafter, a case where the light transmitting area OA and the light blocking area LSA are applied to the first area and the second area having different light transmittances from each other, respectively, is shown as an example, but the embodiment is not limited thereto. For example, both the first area and the second area may be light transmitting areas through which incident light is transmitted by about 50% or more, but the light transmittance of the second area is lower than that of the first area by about 10% or less.

The light transmitting area OA may be divided into a plurality of unit light transmitting areas OAn by the light blocking area LSA. The respective unit light transmitting areas OAn may be separated and spaced apart from each other. Each of the unit light transmitting areas OAn may have a hexagonal shape in a plan view, but the shape thereof is not limited thereto. For example, each of the unit light transmitting areas OAn may have a shape of a rectangle, a square, or a pentagon, or may have a shape such as a circle or an ellipse. The size of each of the unit light transmitting areas OAn and the interval between the unit light transmitting areas OAn may be substantially uniform.

The unit light transmitting areas OAn may be disposed to be spaced apart from each other with the light blocking area LSA interposed therebetween. The light blocking area LSA may surround each of the unit light transmitting areas OAn on the plane. In addition, the light blocking area LSA may be integrally connected between the plurality of unit light transmitting areas OAn. Details of the light transmitting area OA and the light blocking area LSA will be described later.

One side of the flexible film430may be disposed on a portion of the fingerprint sensor substrate FSUB that is not covered by the light sensing layer410. The flexible film430may be attached to one end of the fingerprint sensor substrate FSUB by, for example, using an anisotropic conductive film or ultrasonic bonding. The flexible film430may be electrically connected to a fingerprint pad of the fingerprint sensor substrate FSUB. The flexible film430may be a flexible printed circuit board, a printed circuit board, or a flexible film such as a chip on film.

The other side of the flexible film430may be disposed on the sensor circuit board440. The other side of the flexible film430may be attached to the sensor circuit board440through a conductive adhesive member such as an anisotropic conductive film. Thus, the flexible film430may be electrically connected to the sensor circuit board440. Although the present invention is not limited thereto, the flexible film430may be connected to the sensor circuit board440in the form of a chip on film. The sensor circuit board440may be a flexible printed circuit board or a printed circuit board.

The sensor driving circuit450may be disposed on the sensor circuit board440. However, the present invention is not limited thereto, and for example, the sensor driving circuit450may be disposed on the flexible film430. The sensor driving circuit450may receive sensing voltages of the sensor pixels SP (refer toFIG.3) of the light sensing layer410through the flexible film430and the sensor circuit board440. Accordingly, the sensor driving circuit450may recognize the fingerprint pattern of a finger according to the sensing voltages of each of the sensor pixels SP.

FIG.3is a plan view of a fingerprint sensor according to an embodiment of the present invention.FIG.4is a cross-sectional view of a display device according to an embodiment of the present invention.FIG.5is an enlarged view of the area A ofFIG.4.FIG.6is an enlarged view of the area B ofFIG.5.FIG.3illustrates an enlarged view of a part of the plane of the optical layer420of the fingerprint sensor400.FIG.4illustrates a partial cross-sectional view of the display panel100and the fingerprint sensor400. It is illustrated inFIG.4that a user's finger F touches the display device10for fingerprint recognition.

Referring toFIGS.3to6, the display device10may further include a cover window CW disposed on the upper surface of the display panel100and an adhesive member STM for attaching the display panel100and the fingerprint sensor400to each other. The cover window CW may be disposed on the display panel100to cover the upper surface of the display panel100. The cover window CW may serve to protect the display panel100and lower members. For example, the cover window CW may be attached to the upper surface of the display panel100using a transparent adhesive member.

The cover window CW may be made of a transparent material, and may be glass or plastic. For example, when the cover window CW is glass, it may be an ultra thin glass (UTG) having a thickness of about 0.1 mm or less. When the cover window CW is made of plastic, it may include a transparent polyimide film.

The adhesive member STM may be interposed between the fingerprint sensor400and the display panel100, and may attach the fingerprint sensor400and the display panel100to each other. The adhesive member STM may be optically transparent. Although not limited thereto, the adhesive member STM may be, for example, a transparent adhesive film such as an optically clear adhesive (OCA) film or a transparent adhesive resin such as an optically clear resin (OCR).

The adhesive member STM may compensate for a step between the light transmitting area OA and light blocking area LSA of the optical layer420. For example, as will be described later, a step GP may be provided between one surface421aof a light transmitting member421disposed in the light transmitting area OA and one surface422aof a light blocking member422disposed in the light blocking area LSA and between one surface421aof a light transmitting member421disposed in the light transmitting area OA and one surface423aof a sub-light blocking member423. Even when the step GP is provided, the adhesive member STM may be interposed between the fingerprint sensor400and the display panel100to compensate for the step GP. Accordingly, the fingerprint sensor400and the display panel100may be attached to each other.

The light sensing layer410may recognize a fingerprint by recognizing light incident through the optical layer420. Although not shown, the light sensing layer410may include a light sensing element and at least one transistor. Although not limited thereto, for example, each of the sensor pixels SP of the light sensing layer410may include a light sensing element and at least one transistor. The light sensing element may convert light energy into electrical energy, and may have photovoltaic power in which a current flowing according to the intensity of light changes. For example, the light sensing element may be a photodiode. When a driving signal is supplied, the transistor of the light sensing layer410may be turned on to transmit a current flowing through the light sensing element. Based on the current converted by the light sensing element and transmitted by the transistor of the light sensing layer410, a fingerprint may be detected.

For example, each of the sensor pixels SP of the light sensing layer410may overlap at least one unit light transmitting area OAn in the thickness direction (third direction DR3). For example, each of the sensor pixels SP may overlap at least one light transmitting member421. Although it is shown in the drawing that one sensor pixel SP overlaps two unit light transmitting areas OAn in the thickness direction (e.g., the third direction DR3), the number of unit light transmitting areas OAn overlapping the sensor pixel SP in the thickness direction (the third direction DR3) is not limited thereto. For example, the number of unit light transmitting areas OA overlapping one sensor pixel SP may be in the range of about 100 to about 1000, or may be in the range of about 10 to about 10000. For example, the sensor pixel SP may overlap one unit light transmitting area OAn in the thickness direction (third direction DR3).

The fingerprint of the finger F may be shaped by protruding ridge RID and valleys VAL depressed therefrom. When the finger F touches the cover window CW, the ridge RID of the fingerprint directly contacts the cover window CW, and the valley VAL may be spaced from the cover window CW by a predetermined distance. Light traveling toward the finger F may be reflected from each of the ridge RID and valley VAL of the finger F to be directed toward the light sensing layer410. The light traveling toward the finger F may be light emitted from the display panel100, but the present invention is not limited thereto.

In this case, the light reflected from the ridge RID and valley VAL of the finger F may have different optical characteristics from each other. For example, the light reflected from the ridge RID and the light reflected from the valley VAL may have different frequencies, wavelengths, and intensities from each other. Accordingly, each sensor pixel SP of the light sensing layer410may output sensing signals having different electrical characteristics corresponding to the optical characteristics of light reflected from each of the ridge RID and the valley VAL. The sensing signals output by each sensor pixel SP may be converted into image data, and thus a user's fingerprint may be identified.

The light transmitting area OA of the optical layer420may be a path through which light reflected from the ridge RID and valley VAL of the finger F is incident. For example, when the user's finger F is in contact with the cover window CW, the light reflected from the finger F may be incident on the sensor pixel SP of the sensing layer410through the display panel100and the light transmitting area OA of the optical layer420.

The light blocking area LSA of the optical layer420may block a part of light incident on the light sensing layer410. The light blocking area LSA may control the range LR of the light incident on the sensor pixel SP through the light transmitting area OA. For example, in the light blocking area LSA, each sensor pixel PS of the light sensing layer410may allow the light reflected in the specific range LR to reach the light sensing layer410, and the incident light reflected from an area other than the range LR may be blocked.

The range LR of light incident on the sensor pixel SP through the light transmitting area OA of the optical layer420may be shorter than the distance FP between the ridge RID and valley VAL of the fingerprint of the finger F. The distance FP between the ridge RID and valley VAL of the fingerprint of the finger F may be about 500 μm. Accordingly, each sensor pixel SP may distinguish the light reflected from the ridge RID and/or valley VAL of the fingerprint of the finger F.

The optical layer420may further include a light transmitting member421, a light blocking member422, and a planarization member423. The light transmitting member421may be disposed in the light transmitting area OA, and the light blocking member422and the planarization member423may be disposed in the light blocking area LSA.

The light transmitting member421, the light blocking member422, and the planarization member423may be disposed on the light sensing layer410. For example, the light transmitting member421, the light blocking member422, and the planarization member423may be directly disposed on the light sensing layer410. However, the present invention is not limited thereto, and for example, the optical layer420may further include a base substrate between the light sensing layer410and the light transmitting member421, the light blocking member422, and the planarization member423, and in this case, for example, the light transmitting member421, the light blocking member422, and the planarization member423may be disposed on the base substrate.

A plurality of the light transmitting members421may be provided, and the plurality of light transmitting members421may be separated and spaced apart from each other. For example, each light transmitting member421may have an island shape in a plan view. For example, each light transmitting member421may have a polygonal shape. The light blocking member422may be disposed between the plurality of light transmitting members421and may fill a space between the light transmitting members421adjacent to each other. The planarization member423may be disposed on the light blocking member422. The planarization member423may overlap the light blocking member422in the thickness direction (e.g., the third direction DR3), and may cover at least a part of the light blocking member422. The planarization member423may be disposed on the light blocking member422.

The light transmitting member421, the light blocking member422, and the planarization member423may include one (e.g., first) surfaces421a,422a, and423a, respectively. The first surfaces421a,422a, and423amay refer to upper surfaces of the light transmitting member421, the light blocking member422, and the planarization member423, respectively. When the fingerprint sensor400is located under the display panel100, the first surfaces421a,422a, and423aof the light transmitting member421, the light blocking member422, and the planarization member423may face the display panel100.

The light blocking member422may be integrally formed, but the present invention is not limited thereto. The light blocking member422may fill the space between the light transmitting members421. For example, the light transmitting members421may be separated by the light blocking member422. The light blocking member422may include a recess422b. For example, the light blocking member422may provide a recess422b. The recess422bmay be connected to the first surface422aof the light blocking member422. For example, the recess422bmay have a concave shape toward the lower portion of the optical layer420. For example, the depth of the recess422bwith respect to the first surface422aof the light blocking member422may decrease toward the light transmitting member421, and may increase toward the vicinity of a center between the light transmitting members421adjacent to each other, but the present invention is not limited thereto. For example, the depth of the recess422bmay be the greatest at a region of the light blocking member422that is between adjacent light transmitting members421.

The planarization member423may be disposed on the light blocking member422, and may expose a part of the light blocking member422, but the present invention is not limited thereto. The planarization member423may be located on the recess422bof the light blocking member422, and in this case, the planarization member423may expose the first surface422aof the light blocking member422. The planarization member423may be integrally formed, but the present invention is not limited thereto. For example, the thickness of the planarization member423may decrease toward the light transmitting member421, and may increase toward the vicinity of a center between the adjacent light transmitting members421, but the present invention is not limited thereto. the first surface422aof the light blocking member422may be exposed by the planarization member423. The first surface422aof the light blocking member422exposed by the planarization member423and the first surface423aof the planarization member423may be located at substantially the same height (for example, second height h2). For example, the first surface422aof the light blocking member422and the first surface423aof the planarization member423may be substantially located on the same plane. However, the present invention is not limited thereto.

The first surface421aof the light transmitting member421, and the first surface422aof the light blocking member422and the first surface423aof the planarization member423may be located at different heights with respect to one surface or the other surface of the light sensing layer410. For example, the first surface421aof the light transmitting member421may be located at a first height h1, and the first surface422aof the light blocking member422and the first surface423aof the planarization member423may be located at a second height h2. The first height h1may be positioned higher than the second height h2based on one surface or the other surface of the light sensing layer410. For example, a step GP may be provided by the first surface421aof the light transmitting member421and first surfaces422aand423aof the light blocking member422and the planarization member423. Although not limited thereto, for example, the size of the step GP may be in the range of about 50 nm to about 60 nm, in the range of about 30 nm to about 80 nm, or in the range of about 10 nm to about 100 nm.

Further, the light transmitting area OA and the light blocking area LSA may have different thicknesses from each other. For example, the light transmitting area OA may have a first thickness d1, and the light blocking area LSA may have second thickness d2. In this case, the first thickness d1may be greater than the second thickness d2, and the difference between the first thickness d1and the second thickness d2may be substantially the same as the size of the step GP.

In a plan view, the planarization member423may at least partially surround the light transmitting member421, and the light blocking member422may be located between the planarization member423and the light transmitting member421. In this case, the light blocking member422may surround the light transmitting member421, and the planarization member423may surround the light transmitting member421as well as the light blocking member422. The light transmitting member421and the planarization member423may be spaced apart from each other and may not directly contact each other, but the present invention is not limited thereto.

The light transmitting member421, the light blocking member422, and the planarization member423may have different light transmittances from each other. The light transmittance of the light transmitting member421may be greater than the light transmittance of the light blocking member422. The light transmittance of the planarization member423may be smaller than the light transmittance of the light transmitting member421, and may be greater than the light transmittance of the light blocking member422. Here, the light transmittance may refer to a degree to which external light transmits through the light transmitting member421, the light blocking member422, or the planarization member423in the thickness direction (e.g., the third direction DR3). The light transmittances of the light transmitting member421, the light blocking member422, and the planarization member423may be measured at substantially the same thickness.

Although not limited thereto, for example, the light transmittance of the light transmitting member421may be in a range of more than about 90% to less than about 100%, or in a range of more than about 80% to less than about 100%. The light transmittance of the light blocking member422may be in a range of more than about 0% to less than about 1%, or in a range of more than about 0% to less than about 10%. The light transmittance of the planarization member423may be in a range of more than about 50% to less than about 70%, or in a range of more than about 40% to less than about 80%.

The light transmitting member421may include a first organic material. The first organic material may have high light transmittance. Although not limited thereto, for example, the first organic material may include at least one of, for example, acrylic resin, epoxy resin, phenolic resin, polyamide resin, and/or polyimide resin.

The light blocking member422may include a second organic material and a light absorbing material. Although not limited thereto, for example, the second organic material may include at least one of, for example, acrylic resin, epoxy resin, phenolic resin, polyamide resin, and/or polyimide resin. For example, the second organic material may be substantially the same as the first organic material of the light transmitting member421, but the present invention is not limited thereto.

Although not limited thereto, for example, the light absorbing material may include an inorganic black pigment such as carbon black or an organic black pigment. In addition, the light absorbing material may include a black dye, or may include a pigment or dye of other colors except for a black color. The light blocking member422may further include a negative-type photosensitive material (or, e.g., a sensitizer).

The planarization member423may include a third organic material and a positive-type photosensitive material (or, e.g., a sensitizer). For example, the third organic material may include at least one of acrylic resin, epoxy resin, phenolic resin, polyamide resin, and/or polyimide resin. The third organic material may be substantially the same as the first organic material of the light transmitting member421, but the present invention is not limited thereto.

As the planarization member423is disposed on the light blocking member422, the etching of the light blocking member422disposed in the light blocking area LSA may be minimized during the process of etching the light blocking member422, so that the reliability of the fingerprint sensor400may be increased, and the contamination inside a chamber in which the etching process is performed may be minimized. Further, since the light blocking member422(or a material layer422mfor the light blocking member422, refer toFIG.10) located on the light transmitting member421may be more easily etched through the planarization member423, and it may be easier to remove (or, e.g., lift off) a mask pattern (MS, refer toFIG.8) for patterning the light transmitting member421. In addition, it may be possible to suppress or prevent the over-etch of the light transmitting member421, so that it is possible to further increase the reliability of the fingerprint sensor400.

Hereinafter, a laminated structure of the display panel100according to an embodiment of the present invention will be described with reference toFIG.7.

FIG.7is a cross-sectional view of a display panel according to an embodiment of the present invention.FIG.7illustrates a cross-sectional structure of one pixel of the display panel100.

Referring toFIG.7, the display panel100according to an embodiment of the present invention includes a plurality of pixels, and each of the pixels may include at least one thin film transistor (e.g., a second transistor ST2). The display panel100may include a display base substrate SUB, a barrier layer110, a buffer layer120, a semiconductor layer130, a first insulating layer IL1, a first gate conductive layer140, a second insulating layer IL2, a second gate conductive layer150, a third insulating layer IL3, a data conductive layer160, a fourth insulating layer IL4, an anode electrode ANO, a pixel defining layer PDL, a light-emitting layer EML, a cathode electrode CAT disposed on the light-emitting layer EML and the pixel defining layer PDL, and a thin film encapsulation layer EN disposed on the cathode electrode CAT. The pixel defining layer PDL includes an opening exposing the anode electrode ANO, and the light-emitting layer EML is disposed in the opening of the pixel defining layer PDL. Each of the above-described layers may be formed as a single layer, but may be formed as a laminated layer including a plurality of layers. Another layer may be disposed between the respective layers.

The display base substrate SUB supports the respective layers disposed thereon. The display base substrate SUB may be made of an insulating material such as a polymer resin, or may be made of an inorganic material such as glass or quartz. However, the present invention is not limited thereto, and the display base substrate SUB may be a transparent plate or a transparent film.

For example, the display base substrate SUB may be a flexible substrate capable of bending, folding, rolling, or the like, but the present invention is not limited thereto. For example, the display base substrate SUB may be a rigid substrate.

The barrier layer110is disposed on the display base substrate SUB. The barrier layer110may prevent the diffusion of impurity ions, and may prevent the penetration of moisture or external air. In addition, the barrier layer110may perform a surface planarization function. For example, the barrier layer110may include at least one of silicon oxide (SiOx), silicon nitride (SiNx), and/or silicon oxynitride (SiOxNy). However, the present invention is not limited thereto, and the barrier layer110may be omitted depending on the type or process conditions of the display base substrate SUB.

The buffer layer120is disposed on the barrier layer110. For example, the buffer layer120may include silicon nitride (SiNx), silicon oxide (SiOx), and/or silicon oxynitride (SiOxNy).

The semiconductor layer130is disposed on the buffer layer120. The semiconductor layer130forms a channel of the second transistor ST2of the pixel (“PX” inFIG.3). The semiconductor layer130may include polycrystalline silicon. However, the present invention is not limited thereto, and for example, the semiconductor layer130may include at least one of single crystal silicon, low-temperature polycrystalline silicon, amorphous silicon, and/or an oxide semiconductor.

The first insulating layer IL1is disposed on the semiconductor layer130. The first insulating layer IL1may be a first gate insulating layer having a gate insulating function. The first insulating layer IL1may include at least one of a silicon compound and a metal oxide.

The first gate conductive layer140is disposed on the first insulating layer IL1. The first gate conductive layer140may include a gate electrode GAT of the second transistor ST2of the pixel, a scan line connected thereto, and a first electrode CE1of a storage capacitor.

The first gate conductive layer140may include at least one of molybdenum (Mo), aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), calcium (Ca), titanium (Ti), tantalum (Ta), tungsten (W), and/or copper (Cu).

The second insulating layer IL2may be disposed on the first gate conductive layer140. The second insulating layer IL2may be an interlayer insulating layer or a second gate insulating layer. The second insulating layer IL2may include an inorganic insulating material such as silicon oxide, silicon nitride, silicon oxynitride, hafnium oxide, aluminum oxide, titanium oxide, tantalum oxide, or zinc oxide.

The second gate conductive layer150is disposed on the second insulating layer IL2. The second gate conductive layer150may include a second electrode CE2of a storage capacitor. The second gate conductive layer150may include at least one of molybdenum (Mo), aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), calcium (Ca), titanium (Ti), tantalum (Ta), tungsten (W), and/or copper (Cu). The second gate conductive layer150may be made of the same material as the first gate conductive layer140, but the present invention is not limited thereto.

The third insulating layer IL3is disposed on the second gate conductive layer150. The third insulating layer IL3may be an interlayer insulating layer. The third insulating layer IL3may include an inorganic insulating material such as silicon oxide, silicon nitride, silicon oxynitride, hafnium oxide, aluminum oxide, titanium oxide, tantalum oxide, or zinc oxide.

The data conductive layer160is disposed on the third insulating layer IL3. The data conductive layer160may include a first electrode SD1and a second electrode SD2of the second transistor ST2of one pixel of the display panel, and a first power voltage electrode ELVDDE. The first electrode SD1and second electrode SD2of the second transistor ST2may be electrically connected to a source region and a drain region of the semiconductor layer130through corresponding contact holes penetrating the third insulating layer IL3, the second insulating layer IL2, and the first insulating layer ILL. The first power voltage electrode ELVDDE may be electrically connected to the second electrode CE2of the storage capacitor through a contact hole penetrating the third insulating layer IL3.

The data conductive layer160may include at least one of aluminum (Al), molybdenum (Mo), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), calcium (Ca), titanium (Ti), tantalum (Ta), tungsten (W), and/or copper (Cu). The data conductive layer160may be a single layer or multiple layers. For example, the data conductive layer160may be formed as a laminated structure of Ti/Al/Ti, Mo/AI/Mo, Mo/AlGe/Mo, or Ti/Cu.

The fourth insulating layer IL4is disposed on the data conductive layer160. The fourth insulating layer IL4covers the data conductive layer160. The fourth insulating layer IL4may be a via layer. The fourth insulating layer IL4may include an organic insulating material. When the fourth insulating layer IL4includes an organic material, the upper surface thereof may be substantially flat despite a lower step.

The anode electrode ANO is disposed on the fourth insulating layer IL4. The anode electrode ANO may be a pixel electrode provided for each pixel. The anode electrode ANO may be connected to the second electrode SD2of the second transistor ST2through a contact hole penetrating the fourth insulating layer IL4. The anode electrode ANO may at least partially overlap the light-emitting area EMA of the pixel.

The anode electrode ANO may have, but is not limited to, a laminated film structure in which a high-work-function material layer and a reflective material layer are laminated. The high-work-function material layer may include, for example, Indium-Tin-Oxide (ITO), Indium-Zinc-Oxide (IZO), Zinc Oxide (ZnO), and/or Indium Oxide (In2O3). For example, the reflective material layer may include silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), lead (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), or a mixture thereof. For example, the high-work-function material layer may be disposed above the reflective material layer, and may thus be disposed closer to the light-emitting layer EML. For example, anode electrode ANO may have a multilayer structure of ITO/Mg, ITO/MgF, ITO/Ag, or ITO/Ag/ITO, but the present invention is not limited thereto.

The pixel defining layer PDL may be disposed on a portion of the anode electrode ANO. The pixel defining layer PDL may be disposed on the anode electrode ANO, and may include an opening exposing at least a portion of the anode electrode ANO. The light-emitting area EMA and the non-light-emitting area NEM may be divided by the pixel defining layer PDL and the opening thereof. The pixel defining layer PDL may include an organic insulating material. However, the present invention is not limited thereto, and the pixel defining layer PDL may include an inorganic material.

A spacer SC may be disposed on the pixel defining layer PDL. The spacer SC may serve to maintain a gap with a structure disposed thereon. Like the pixel definition layer PDL, the spacer SC may include an organic insulating material.

The light-emitting layer EML is disposed on the portion of the anode electrode ANO exposed by the pixel defining layer PDL. The light-emitting layer EML may include an organic material layer. The organic material layer of the light-emitting layer includes an organic light-emitting layer, and may further include a hole injection/transport layer and/or an electron injection/transport layer.

The cathode electrode CAT may be disposed on the light-emitting layer EML. The cathode electrode CAT may be a common electrode disposed over pixels without distinction of the pixels. For example, the cathode electrode CAT may be entirely disposed over the pixels. The anode electrode ANO, the light-emitting layer EML, and the cathode electrode CAT may each constitute an organic light-emitting element.

The cathode electrode CAT may include a low-work-function material layer including, for example, Li, Ca, LiF/Ca, LiF/Al, Al, Mg, Ag, Pt, Pd, Ni, Au Nd, Ir, Cr, BaF, Ba, or a compound or mixture thereof (for example, a mixture of Ag and Mg). The cathode electrode CAT may further include a transparent metal oxide layer disposed on the low-work-function material layer.

A thin film encapsulation layer EN including a first inorganic layer EN1, a first organic layer EN2, and a second inorganic layer EN3is disposed on the cathode electrode CAT. For example, at an end of the thin film encapsulation layer EN, the first inorganic layer EN1and the second inorganic layer EN3may contact each other. For example, first organic layer EN2may be sealed by the first inorganic layer EN1and the second inorganic layer EN3.

Each of the first inorganic layer EN1and the second inorganic layer EN3may include, for example, silicon nitride, silicon oxide, or silicon oxynitride. The first organic layer EN2may include an organic insulating material.

Hereinafter, a method of manufacturing the display device10according to an embodiment of the present invention will be described.

FIGS.8to12are cross-sectional views illustrating a method of manufacturing a display device according to an embodiment of the present invention.FIGS.8to12are cross-sectional views for each manufacturing process illustrating an optical layer420of the fingerprint sensor400of the display device10according to an embodiment of the present invention.

First, referring toFIG.8, a light transmitting member material layer is formed on the light sensing layer410, and is etched using a mask pattern MS to form a light transmitting member421. For example, the light transmitting member material layer is formed on the entire upper surface of the light sensing layer410.

For example, a light transmitting member material layer may be formed over the entire area of the light sensing layer410. The light transmitting member material layer may include substantially the same material as the aforementioned light transmitting member421. Thereafter, a mask pattern MS is patterned on the light transmitting member material layer. The mask pattern MS may include substantially the same planar pattern as the light transmitting member421, and a plurality of mask patterns may be provided. The mask pattern MS may include at least one of a transparent conductive oxide (TCO) and/or an inorganic layer. Although not limited thereto, for example, the transparent conductive oxide (TCO) may include at least one of indium tin oxide (ITO) and/or indium zinc oxide (IZO), and the inorganic layer includes aluminum (Al) or the like.

The light transmitting member material layer may be patterned by etching the light transmitting member material layer using the patterned mask pattern MS as an etching mask to form the light transmitting member421. For example, the process of etching the light transmitting member material layer may be performed by dry etching, but the present invention is not limited thereto, and the process thereof may also be performed by wet etching. A part of the first light transmitting member material layer in a portion not covered by the mask pattern MS may be removed, and only a portion covered by the mask pattern MS may remain.

Subsequently, referring toFIG.9, a light blocking member material layer422mis formed on the light sensing layer140on which the light transmitting member421is disposed, and a planarization member material layer423mis formed on the light blocking member material layer422m.

For example, a light blocking member material layer422mis formed on the light sensing layer410on which the first light transmitting member material layer421mis disposed. The light blocking member material layer422mmay include substantially the same material as the above-described light blocking member422. The light blocking member material layer422mmay cover the light transmitting member421and the mask pattern MS, and may be formed over the light sensing layer410. For example, the light blocking member material layer422mmay be formed over the entire area of the light sensing layer410. For example, the light blocking member material layer422mmay cover the entire area of the side surface of the light transmitting member421. The light blocking member material layer422mmay cover the side surface and upper surface of the mask pattern MS.

The thicknesses of the light blocking member material layer422mdisposed on the upper surface of each mask pattern MS may be different from each other. For example, the first thickness TH1of the light blocking member material layer422mdisposed on the upper surface of one mask pattern MS may be larger than the second thickness TH2of the light blocking member material layer422mdisposed on the upper surface of another mask pattern MS adjacent to the one mask pattern MS.

A planarization member material layer423mmay be disposed on the light blocking member material layer422m. For example, the planarization member material layer423mmay be disposed over the entire area of the light blocking member material layer422m. The light blocking member material layer422mmay be provided with a step between the upper surface of a portion thereof disposed in the unit light transmitting area OAn and the upper surface of a portion thereof disposed in the light blocking area LSA and between the upper surfaces of portions thereof disposed in the unit light transmitting areas OAn. In this case, since the planarization member material layer423mmay be disposed on the light transmitting member421, the mask pattern MS and the light blocking member422m, the step may be compensated, and the upper surface of the planarization member material layer423mmay be substantially flat.

The planarization member material layer423mmay include substantially the same material as the above-described planarization member423. Although not limited thereto, the thickness of the planarization member material layer423mmay be, for example, in the range of about 5 μm to about 15 μm or in the range of about 1 μm to about 20 μm. Here, the thickness of the planarization member material layer423mmay refer to an average thickness of the entire area of the planarization member material layer423m.

After the light blocking member material layer422mand the planarization member material layer423mare formed, the entire area of the planarization member material layer423mis exposed. For example, an upper surface of the planarization member material layer423mmay be exposed.

Subsequently, referring toFIG.10, the exposed planarization member material layer423mmay be developed, thereby reducing the thickness of the planarization member material layer423m.

For example, the planarization member material layer423mmay include a positive-type photosensitive material, and in this case, the exposed portion thereof does not maintain a cured state and has a property of being soluble in a developer. Accordingly, the thickness of the planarization member material layer423mmay be reduced by developing the exposed portion through a developer. After the development, the remaining portion may be cured.

Subsequently, referring toFIG.11, the light blocking member material layer422mand the planarization member material layer423mremaining after the development are etched to form a light blocking member422and a planarization layer423.

For example, the light blocking member material layer422mand the planarization member material layer423mremaining after the development are etched to pattern the remaining light blocking member material layer422mand the remaining planarization member material layer423mto form the light blocking member422and the planarization layer423. For example, the process of etching the light blocking member material layer422mand the planarization member material layer423mremaining after the development to form the light blocking member422and the planarization layer423may be performed by dry etching, but the present invention is not limited thereto.

Through the etching process, the height of one surface of the light blocking member422is substantially the same as the height of one surface of the planarization member423, and the upper surface422a(refer toFIG.6) of the light blocking member422may be exposed. For example, an upper surface of the light blocking member422and an upper surface of the planarization member423may be coplanar. Further, the height of one surface of the light blocking member422and the height of one surface of the planarization member423may be located at a height lower than the height of one surface of the light transmitting member421.

As the planarization member material layer423mis disposed on the light blocking member material layer422m, even if the thickness of the light blocking member material layer422mdisposed on each mask pattern MS is different, the light blocking member material layer422mdisposed on each mask pattern MS may be removed simultaneously from each mask pattern MS. For example, as the planarization member material layer423mis disposed on the light blocking member material layer422m, the thicknesses of the organic layers disposed on each mask pattern MS may be substantially the same as each other.

Both the light blocking member material layer422mand the planarization member material layer423mmay each include an organic material, and in this case, the degree to which both material layers are etched may be substantially the same. The light blocking member material layer422mand the planarization member material layer423mremaining after development can be etched at the same time, and accordingly, the light blocking member material layer422mdisposed on each mask pattern MS may be removed simultaneously from each mask pattern MS even if the thickness of the light blocking member material layer422mdisposed on each mask pattern MS is different. Accordingly, it is possible to suppress or prevent the light blocking member material layer422mfrom remaining on the mask pattern MS, and thereafter, the removal of the mask pattern MS may be easier.

Further, over-etching for removing all the light blocking member material layers422mdisposed on each mask pattern MS and having different thicknesses may be unnecessary. Accordingly, damage to the light transmitting member421due to over-etching of the light blocking member material layer422mcan be suppressed or prevented, and further, deterioration in reliability of the fingerprint sensor400can be suppressed or prevented.

In addition, as the light blocking member material layer422mis covered by the planarization member material layer423m, the upper surface of the light blocking member422and the upper surface of the planarization member423may be substantially flat, and etching of the light blocking member material layer422mdisposed in the light blocking area LSA may be minimized. Therefore, since an additional configuration for planarization may be unnecessary, the manufacturing process may be simplified, the process cost may be reduced, and the contamination inside a chamber in which the etching process is performed may be minimized.

Subsequently, referring toFIG.12, after the light blocking member422and the planarization member423are formed, the mask pattern MS is removed. The mask pattern MS may be removed through wet etching, but the present invention is not limited thereto.

Even if the thickness of the light blocking member material layer422mdisposed on each mask pattern MS is different, as the planarization member material layer423mis further disposed, the light blocking member material layer422mdisposed on each mask pattern MS may be removed simultaneously. Accordingly, each mask pattern MS may be exposed without being covered by the light blocking member material layer422m, and may be easily removed by the wet etching. As the mask pattern MS is easily removed, reliability of the fingerprint sensor400may be increased.

Hereinafter, embodiments of the display device will be described. In the following embodiments, descriptions of the same components as those of the previously described embodiments will be omitted or simplified, and differences will be mainly described.

FIG.13is a cross-sectional view of a display device according to an embodiment of the present invention.

Referring toFIG.13, a display device10_1according to the present embodiment is different from the display device10of the embodiment ofFIG.4in that it further includes an overcoat layer OC_1. The overcoat layer OC_1according to the present embodiment may cover the light transmitting member421, the light blocking member422, and the planarization member423, and may overlap the light sensing layer410. For example, the overcoat layer OC_1may overlap the entire upper surface of the light sensing layer410. The adhesive member STM may be disposed on the overcoat layer OC_1. Although not limited thereto, the overcoat layer OC_1may include an organic material, but may also include an inorganic material.

Even in this case, the light blocking member material layer422m(refer toFIG.10) disposed on the mask pattern MS (refer toFIG.11) may be easily etched, the mask pattern MS (refer toFIG.11) may be easily removed, damage to the light transmitting member421may be prevented, and etching of the light blocking member422in the light blocking area LSA may be minimized. In addition, as the overcoat layer OC_1covers the light transmitting member421, the light blocking member422, and the planarization member423, the upper portions of the light transmitting member421, the light blocking member422, and the planarization member423may be flattened, and may be more easily attached to the display panel100.

FIG.14is a cross-sectional view of a fingerprint sensor of a display device according to an embodiment of the present invention.

Referring toFIG.14, a fingerprint sensor400_2according to the present embodiment is different from the fingerprint sensor400of the embodiment ofFIG.5in that the height h1of one surface of a light transmitting member421_2of the fingerprint sensor400_2is substantially the same as the height h2of one surface of each of a light blocking member422_2and planarization member423_2of the fingerprint sensor400_2. For example, the heights h1and h2of the light transmitting member421_2, the light blocking member422_2, and the planarization member423_2of the fingerprint sensor400_2may be located at the same height with respect to one surface or the other surface of the light sensing layer410(refer toFIG.4), and may be located on substantially the same plane. For example, the upper surfaces of the light transmitting member421_2, the light blocking member422_2and the planarization member423_2may be coplanar.

Even in this case, the light blocking member material layer422m(refer toFIG.10) disposed on the mask pattern MS (refer toFIG.11) may be easily etched, the mask pattern MS (refer toFIG.11) may be easily removed, damage to the light transmitting member421may be prevented, and etching of the light blocking member422in the light blocking area LSA may be minimized. In addition, as the heights h1and h2of the light transmitting member421_2, the light blocking member422_2, and the planarization member423_2of the fingerprint sensor400_2are located at the same height, the upper portion of the fingerprint sensor4002may be substantially flat, and may be more easily attached to the display panel100.

FIG.15is a cross-sectional view of a fingerprint sensor of a display device according to an embodiment of the present invention.

Referring toFIG.15, a fingerprint sensor400_3according to the present embodiment is different from the fingerprint sensor400of the embodiment ofFIG.5in that the height h1of one surface of a light transmitting member421_3of the fingerprint sensor400_3is located at a height lower than the height h2of one surface of each of a light blocking member422_3and planarization member423_3of the fingerprint sensor400_3with respect to one surface or the other surface of the light sensing layer410(refer toFIG.4).

Even in this case, the light blocking member material layer422m(refer toFIG.10) disposed on the mask pattern MS (refer toFIG.11) may be easily etched, the mask pattern MS (refer toFIG.11) may be easily removed, damage to the light transmitting member421may be prevented, and etching of the light blocking member422in the light blocking area LSA may be minimized. In addition, as the height h2of one surface of each of the light blocking member422_3and planarization member423_3of the fingerprint sensor400_3is located at a height higher than the height h1of one surface of the light transmitting member421_3of the fingerprint sensor400_3, the light blocking area LSA may more easily block external light from entering the light transmitting member421_3, and reliability of fingerprint sensing may be increased.

FIG.16is a cross-sectional view of a fingerprint sensor of a display device according to an embodiment of the present invention.

Referring toFIG.16, a fingerprint sensor400_4according to the present embodiment is different from the fingerprint sensor400of the embodiment ofFIG.5in that a planarization member423_4of the fingerprint sensor400_4covers a light blocking member422_4. For example, the planarization member423_4may completely cover the upper surfaces of the light blocking member422_4. In other words, the planarization member423_4may be formed in substantially the same pattern as the light blocking member422_4in a plan view, and the planarization member423_4may overlap the light blocking member422_4in the thickness direction. For example, the light blocking member422_4and the planarization member423_4may completely overlap each other in the thickness direction. Accordingly, the entire area of the light blocking member422_4may be covered by the planarization member423_4, and may not be exposed.

Even in this case, the light blocking member material layer422m(refer toFIG.10) disposed on the mask pattern MS (refer toFIG.11) may be easily etched, the mask pattern MS (refer toFIG.11) may be easily removed, damage to the light transmitting member421_4may be prevented, and etching of the light blocking member422_4in the light blocking area LSA may be minimized. In addition, the light blocking member422_4and the planarization member423_4may be configured to have various arrangements, so that the arrangement of the components may be changed as desired.

While the present invention has been described with reference to the exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and detail may be made thereto without departing from the spirit and scope of the present invention.