DISPLAY DEVICE

A display device according to an embodiment includes a display panel including a pad area and a flexible printed circuit board connected to the display panel. The flexible printed circuit board includes a body where components are located, a pressing portion disposed along an edge of the body and attached to the pad area, and a bypass portion having an end to another end connected to the boy and including wires.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0061927 under 35 U.S.C. § 119, filed at the Korean Intellectual Property Office (KIPO) on May 12, 2023, the entire contents of which are incorporated herein by reference.

BACKGROUND

1. Technical Field

This disclosure relates to a display device, and more particularly, to a display device including a display panel and a flexible printed circuit board connected thereto.

2. Description of the Related Art

The display device may include pixels and display an image on a display screen by controlling the brightness of each pixel. The display device may include a touch sensing unit capable of sensing a user's touch. The display device may include a display panel on which pixels are formed. The touch sensor may be provided on the display panel. For example, the display panel may include a touch sensing unit, or a panel including the touch sensing unit may be attached to the display panel.

The display device may include a flexible printed circuit board for transmitting signals for driving pixels and signals for driving a touch sensor to a display panel.

SUMMARY

A flexible printed circuit board included in the display device may have a multilayer structure including conductive layers. For example, the flexible printed circuit board may have a structure in which units having conductive layers formed on both sides or one side of a base film are laminated or stacked. In order to reduce the thickness and dead space of the display device, it may be desirable to reduce the thickness and size of the flexible printed circuit board. However, since many types of signals are transmitted through the flexible printed circuit board and a touch driver and the like are mounted on the flexible printed circuit board, it is difficult to reduce the number (thickness) and size of the flexible printed circuit board.

In addition, conductive layers transmitting different signals may overlap each other on the flexible printed circuit board, and thus interference may occur between signals. A conductive layer for shielding these conductive layers is required, making it difficult to reduce the number of layers of the flexible printed circuit board.

Embodiments provide a flexible printed circuit board capable of reducing the number of layers and preventing interference between signals, and a display device including the same.

A display device according to an embodiment includes a display panel including a pad area and the flexible printed circuit board connected to the display panel.

The flexible printed circuit board includes a body where components are located, a pressing portion disposed along an edge of the body and attached to the pad area, and a bypass portion having an end and another end both connected to the body and including wires.

The bypass portion may be bent so that at least a portion of the bypass portion overlaps the body.

The display device may further include a shielding layer disposed between the bypass portion and the body in a bent state of the bypass portion.

The display device may further include a display driver disposed on the display panel, and a cover covering at least a portion of the display driver and the flexible printed circuit board.

The bypass portion may be disposed between the body and the cover in a bent state of the bypass portion.

The display device may further include a double-sided adhesive tape attaches the flexible printed circuit board to a rear surface of the display panel.

The bypass portion may be disposed between the body and the double-sided adhesive tape in a bent state of the bypass portion.

The bypass portion may include a first leg portion and a second leg portion extending from the body, and a connection portion connected between the first leg portion and the second leg portion.

The connection portion and the pressing portion may extend in a same direction.

The first leg portion and the second leg portion may be bent, and the connection portion may be attached to the body.

The flexible printed circuit board may include conductive layers which are sequentially stacked.

A number of the conductive layers included in the bypass portion may be smaller than a number of the conductive layers included in the body.

The number of the conductive layers included in the bypass portion may be equal to a number of the conductive layers included in the pressing portion.

The body portion may include three or more conductive layers, and the bypass may include two or less conductive layers.

The bypass portion may include a support film, a first conductive layer disposed on a first surface of the support film, and a second conductive layer disposed on a second surface of the support film.

The first conductive layer may include a wire transmitting a touch signal, and the second conductive layer may include a ground layer.

The bypass portion may be bent so that at least a portion of the bypass portion overlaps the body.

The second conductive layer may be disposed farther from the body than the first conductive layer in a bent state of the bypass portion.

The portions may include a touch driver.

The wire disposed in the bypass portion may electrically connect the touch driver and the pad of the pressing portion.

A display device according to an embodiment includes a main area including a display area and a touch area, and a sub-area extending from the main area and in which the display driver is located, and a flexible printed circuit board connected to the sub-area.

The flexible printed circuit board includes a body in which the touch driver is located, a pressing portion disposed along an edge of the body and attached to the sub-area, a tail extending from the body and having the connector disposed at an end, and the body and a bypass portion including the first leg portion and the second leg portion extending in the same direction from the first leg portion, and the connection portion connected between the first leg portion and the second leg portion.

The first leg portion and the second leg portion may be bent, and the connection portion may overlap the body.

The display device may further include a shielding layer overlapping the connection portion and the body, and disposed between the connection portion and the body.

The flexible printed circuit board may include conductive layers which are sequentially stacked.

A number of the conductive layers included in the bypass portion may be less than a number of the conductive layers included in the body, and may be equal to a number of the conductive layers included in the pressing portion.

The body may include a first conductive layer, a second conductive layer, a third conductive layer, and a fourth conductive layer arranged in a thickness direction.

The bypass portion, the first conductive layer, and the second conductive layer may include a same conductive layer, or the bypass portion, the third conductive layer, and the fourth conductive layer may include a same conductive layer.

According to embodiments, the flexible printed circuit board capable of reducing the number of layers and preventing interference between signals and the display device including the flexible circuit board may be provided. Further, according to the embodiments, there are advantageous effects that can be recognized throughout the specification.

The technical objectives to be achieved by the disclosure are not limited to those described herein, and other technical objectives that are not mentioned herein would be clearly understood by a person skilled in the art from the description of the disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

With reference to the accompanying drawings, embodiments will be described in detail so that those skilled in the art can carry out.

It will be further understood that the terms “comprise,” “include,” “have,” and the like, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, and/or combinations of them but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or combinations thereof.

In the drawings, the symbols “DR1,” “DR2,” and “DR3” are used to indicate directions, where “DR1” is a first direction, “DR2” is a second direction perpendicular to the first direction, and “DR3” is a third direction perpendicular to the first and second directions.

The term “and/or” includes all combinations of one or more of which associated configurations may define. For example, “A and/or B” may be understood to mean “A, B, or A and B.”

For the purposes of this disclosure, the phrase “at least one of A and B” may be construed as A only, B only, or any combination of A and B. Also, “at least one of X, Y, and Z” and “at least one selected from the group consisting of X, Y, and Z” may be construed as X only, Y only, Z only, or any combination of two or more of X, Y, and Z.

FIG.1is a schematic perspective view of an electronic device1according to an embodiment, andFIG.2is a schematic perspective view of a display device included in the electronic device according to an embodiment.

Referring toFIGS.1and2, the electronic device1may include a display screen that may display an image in a third direction DR3corresponding to the front on a plane defined by the first and second directions DR1and DR2.

For example, examples of the electronic device1may include a mobile phone, a smart phone, a tablet PC, an electronic watch, a smart watch, a watch phone, a television, a laptop computer, a monitor, a head-mounted display (HMD), a mobile communication terminal, an electronic notebook, an e-book reader, a portable multimedia player (PMP), a navigation device, a game machine, a digital camera, a camcorder, a billboard, and the like.

The electronic device1may include a cover window10, a housing20, a display device30, and the like.

The cover window10may include an insulating panel. For example, the cover window10may be made of glass, plastic, or a combination thereof. The front surface of the cover window10may define the front surface of the electronic device1. A region of the cover window10corresponding to the display screen may be optically transparent. The cover window10may be positioned on the display device30to protect the display device30from external impact and transmit an image displayed by the display device30.

The housing20may be made of, e.g., a material with relatively high rigidity. For example, the housing20may include frames and/or plates made of glass, plastic, or metal, or a combination thereof. The housing20can be combined with the cover window10, and the combined housing20and cover window10can constitute the appearance or exterior of the electronic device1and provide an internal space of the electronic device1. For example, the housing20may constitute the rear and side surfaces of the electronic device1, and the cover window10may constitute the front surface of the electronic device1. The display device30and the like may be positioned in the inner or internal space defined by the cover window10and the housing20, and the display device30may be protected from the external environment.

The display device30may display an image and provide a display screen of the electronic device1. The display device30may be a light emitting display device such as an organic light emitting display device, an inorganic light emitting display device, or a quantum dot light emitting display device.

The electronic device1may have various shapes. For example, as shown inFIG.1, the electronic device1may be a quadrangle with rounded corners when viewed from the front. However, the embodiments are not limited thereto. For example, the electronic device1may have a shape such as a rectangle, a square, other polygons, a circle, an ellipse, or the like.

The electronic device1and the display device30may each include a display area DA and a non-display area NA. The display area DA and the non-display area NA shown in FIG.1may correspond to the display area DA and the non-display area NA of the display device30shown inFIG.2. The display area DA may be an area in which an image is displayed and may correspond to the display screen. The non-display area NA may be an area in which an image is not displayed.

The display area DA may occupy most of the region on the center of the front surface of the electronic device1, and the non-display area NA may be adjacent to or surround the display area DA. The display area DA may include a first display area DA1, a second display area DA2, and a third display area DA3. The second display area DA2and the third display area DA3may be areas in which components such as sensors and cameras for adding various functions to the electronic device1are disposed on a side, e.g., a rear side. The second display area DA2and the third display area DA3may correspond to component regions. The second display area DA2and the third display area DA3may be surrounded by the first display area DA1.

In addition to the first display area DA1, the second and third display areas DA2and DA3may display images. Positions and numbers of the second display area DA2and the third display area DA3may be variously changed.

In more detail, the display device30may provide a display screen in the electronic device1. The display device30may detect or photograph the front surface of the electronic device1. The display device30may have a planar shape similar to that of the electronic device1.

The display device30may include a display panel100, a display driver200, a flexible printed circuit board300, a touch driver400, and/or the like.

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

The main area MA may include a display area DA in which pixels displaying an image are arranged, and a non-display area NA around the display area DA. The display area DA may include a first display area DA1, a second display area DA2, and a third display area DA3. A component such as a sensor or a camera may be disposed in the second display area DA2(e.g., on the rear side of the second display area DA2) and the third display area DA3, and the second display area DA2and the third display area DA3correspond to component areas.

The display area DA may emit light from light emitting regions corresponding to the light emitting elements in the third direction DR3. For example, the display panel100may include a pixel circuit part including transistors, signal lines (e.g., gate lines, data lines, and voltage lines) connected to the pixel circuit part, and a light emitting element connected to the pixel circuit part. The display panel100may include a pixel definition layer having an opening defining a light emitting region of each light emitting element. Examples of the light emitting element may include an organic light emitting diode including an organic emission layer, a quantum dot light emitting diode including a quantum dot emission layer, an inorganic light emitting diode including an inorganic semiconductor, and/or a micro light emitting diode.

The non-display area NA may surround the display area DA. The non-display area NA may be defined as an edge region of the main area MA of the display panel100. Circuits and/or signal lines for generating and/or transmitting various signals applied to the display area DA may be disposed in the non-display area NA. For example, in the non-display area NA, a gate driver (not shown) supplying gate signals to the gate lines, and fan-out lines (not shown) connecting the display driver200and the signal lines of the display area DA may be positioned.

The sub-area SA may be a region extending from one side of the main area MA. The sub-area SA may include a flexible region capable of being bent, folded, or rolled. For example, the sub-area SA may be bent to overlap the main area MA in the thickness direction (third direction DR3). The display driver200may be positioned in the sub-area SA, and a pad area may be positioned at an edge of the sub-area SA. The flexible printed circuit board300may be connected to the pad area. In another embodiment, the sub-area SA may be omitted, and the display driver200and the pad area may be disposed in the non-display area NA.

The display driver200may output signals and voltages for driving the display panel100. The display driver200may supply data voltages to the data lines. The display driver200may supply power voltage to power lines, and may supply gate control signals to the gate driver. The display driver200may be provided as an integrated circuit chip, and may be mounted on the display panel100. For example, the display driver200may be disposed in the sub-area SA and may overlap the main area MA in the thickness direction (e.g., third direction DR3) by bending the sub-area SA. In another embodiment, the display driver200may be mounted on the flexible printed circuit board300.

The flexible printed circuit board300may include a body310, a pressing portion320, a tail330, a connector340, and/or a bypass portion350. The body310may occupy the largest region of the flexible printed circuit board300and may be multi-layered. Components such as the touch driver400, a capacitor, a resistor, and an inductor may be disposed on the body310. The pressing portion320(also referred to as a pad area) may be positioned along an edge of the body310. The tail330may extend from the body310, and the connector340may be formed at an end of the tail330. The pressing portion320may be bonded (or attached) to the pad area of the display panel100by using an anisotropic conductive film. Pads positioned on the pressing portion320of the flexible printed circuit board300may be electrically connected to pads positioned in the pad area of the display panel100. The connector340may be connected to an external device such as a graphic system or a power system to receive digital video data and receive power. A mobile industry processor interface (MIPI) may be used for high-speed transmission of digital video data. The bypass portion350can be extended from the body310and may have a flat “⊏” shape. At least a portion of the bypass portion350may be bent to overlap the body310. At least a portion of the bypass portion350may be attached to the body310. Wires may be disposed on the body310and the tail330, and the wires may be connected to components, terminals of the connector340, and/or pads of the pressing portion320. Wires may be disposed in the bypass portion350, and wires of the bypass portion350may be connected to wires of the body310.

The touch driver400may be provided as an integrated circuit chip, and may be mounted on the flexible printed circuit board300. The touch driver400may be electrically connected to a touch sensing part included in the electronic device1. The touch sensing part may be provided in the display area DA of the display panel100. The touch driver400can supply input signals (touch drive signals) to the detection electrodes of the touch detection part, and based on the output signals (touch detection signals) from the detection electrodes, it can detect changes in the capacitance between the detection electrodes. For example, the touch driving signal may be a pulse signal having a frequency (e.g., a predetermined or selectable frequency). The touch driver400may calculate whether there is a touch and touch coordinates based on the amount of changes in capacitance between the sensing electrodes.

FIG.3is a schematic plan view schematically illustrating connections between components of a display device according to an embodiment.

Referring toFIG.3, the display panel100of the display device30may include a display area DA and a non-display area NA. The display area DA may be disposed at the center of the display panel100. Unit pixels PX, gate lines GL, data lines DL, and power lines VL may be disposed in the display area DA. Each part pixel PX may be a minimum unit emitting light and may include a pixel circuit part including a transistor and a capacitor, and a light emitting element receiving a driving current from the pixel circuit part. The unit pixel PX may be connected to the gate line GL, the data line DL, and the power line VL.

The gate lines GL may supply the gate signal applied from a gate driver210to the unit pixels PX. The gate lines GL may extend in the first direction DR1, and may be spaced apart from each other in the second direction DR2. The data lines DL may supply the data voltage applied from the display driver200to the unit pixels PX. The data lines DL may extend in the second direction DR2, and may be spaced apart from each other in the first direction DR1. The power lines VL may supply power voltages applied from the display driver200to the unit pixels PX.

The power voltages may include a high-potential power voltage (or driving voltage), a low-potential power voltage (or common voltage), an initialization voltage, and the like, and these power voltages may be transmitted to the unit pixel PX. The power lines VL may extend in the second direction DR2, and may be spaced apart from each other in the first direction DR1. Sensing electrodes TSE1and TSE2that may sense a touch may be disposed in the display area DA. The sensing electrodes TSE1and TSE2may include first sensing electrodes TSE1arranged in the first direction DR1and second sensing electrodes TSE2arranged in the second direction DR2.

The non-display area NA may surround the display area DA. The gate driver210, fan-out lines FOL, gate control lines GCL, touch signal lines TSL, and the like may be disposed in the non-display area NA. The gate driver210may generate gate signals based on the gate control signals, and may supply the gate signals to the gate lines GL according to a set order. The fan-out lines FOL may extend from the display driver200to the display area DA. The fan-out lines FOL may transfer the data voltages output from the display driver200to the data lines DL. The gate control lines GCL may extend from the display driver200to the gate driver210. The gate control lines GCL may transmit gate control signals output from the display driver200to the gate driver210. The touch signal lines TSL may electrically connect touch pads TP1and TP2and the sensing electrodes TSE1and TSE2.

The display panel100may include a sub-area SA. The display driver200may be positioned in the sub-area SA. The sub-area SA may include a pad area PA.

The display driver200may output signals and voltages for driving the display panel100. The display driver200may supply data voltages to the data lines DL through the fan-out lines FOL. The data voltages may be supplied to the unit pixels PX and may control luminance of the unit pixels PX. The display driver200may supply gate control signals to the gate driver210through the gate control lines GCL.

The pad area PA may be disposed at an edge of the sub-area SA. The pad area PA may include a display pad area DPA, a first touch pad area TPA1, and a second touch pad area TPA2. Display pads DP may be disposed in the display pad area DPA. The display pads DP may be connected to the graphic system through the flexible printed circuit board300. The display pads DP may be connected to the flexible printed circuit board300to receive digital video data and to supply the digital video data to the display driver200. The first touch pad area TPA1and the second touch pad area TPA2may be positioned at one side and another side of the display pad area DPA, respectively. Touch pads TP1and TP2may be disposed in the first and second touch pad areas TPA1and TPA2, and the touch pads TP1and TP2may be connected to touch electrodes TSE1and TSE2positioned in the display area DA and the touch driver400positioned on the flexible printed circuit board300to sense a touch. The pad area PA, the first touch pad area TPA1, and the second touch pad area TPA2may be connected to the flexible printed circuit board300by an anisotropic conductive film (ACF) or a self-assembly anisotropic conductive paste (SAP).

FIG.4is a schematic rear view of a display device according to an embodiment, andFIG.5is a schematic cross-sectional view taken along line A-A′ inFIG.4.

FIGS.4and5illustrate the sub-area SA of the display panel100and an area in which the flexible printed circuit board300is positioned in the display device according to an embodiment. The display panel100may be attached to the cover window10by an adhesive layer ADL such as an optically clear adhesive (OCA).

The sub-area SA of the display panel100may include a bending portion BP, the bending portion BP may be bent so that a portion of the sub-area SA is positioned on the rear surface of the main area MA, and the display driver200positioned in the sub-area SA may be positioned on the rear surface of the main area MA. In order to maintain the bent state of the sub-area SA, the sub-area SA may be attached to the rear surface of the main area MA by a spacer SP including an adhesive layer on sides thereof or a double-sided adhesive tape. The flexible printed circuit board300in which the pressing portion320is bonded to the pad area PA of the sub-area SA may be positioned on the rear surface of the main area MA as the sub-area SA is bent. The body310of the flexible printed circuit board300may be attached to the rear surface of the main area MA by a double-sided adhesive tape DST or a spacer SP including an adhesive layer on the sides. The bypass portion350of the flexible printed circuit board300may be bent so that at least a portion thereof may be positioned under the body310to overlap the body310.

At least portions of the display driver200, the sub-area SA, and the flexible printed circuit board300may be covered by a cover CVR. The cover CVR may be attached to the display driver200, the sub-area SA, and the flexible printed circuit board300. The cover CVR may be applied to cover the at least portions of the display driver200and the flexible printed circuit board300to protect them from electromagnetic interference (EMI) and electrostatic discharge (ESD). The cover CVR can prevent the display driving part200and the pressing portion320from directly contacting an external object, thereby protecting them from physical damage due to friction or the like. The bypass portion350of the flexible printed circuit board300may be positioned between the body310and the cover CVR. The cover CVR can press the bypass portion350of the flexible printed circuit board300so that the bypass portion350can be maintained in a bent state. The cover CVR may be made of a flexible material capable of blocking or shielding from EMI, ESD, and the like. For example, the cover CVR may have a tape shape including a metal layer. The metal layer of the cover CVR may include a metal foil, a metal fabric, a metal mesh, or the like. An adhesive layer may be positioned on one surface of the cover CVR. For example, an adhesive may be applied to, or a double-sided tape may be attached to, one surface of the cover CVR.

Describing the schematic laminated structure of the display panel100, the display panel100may include a display part or display unit (hereinafter “display part”) DU, a touch sensing part or touch sensing unit (hereinafter “touch sensing part”) (not shown) and a reflection reduction layer ARL disposed on the display part DU, and a protective film PF and a protective sheet PS positioned under the display part DU.

The display part DU may include a substrate and a driving element layer, a light emitting element layer, and an encapsulation layer disposed on the substrate.

The substrate may be a base substrate or base member. The substrate may be a flexible substrate including a polymer resin such as polyimide, polyamide, polyethylene terephthalate, etc. The substrate may be a rigid substrate made of a material such as glass. The driving element layer may be positioned on the substrate. The driving element layer may include transistors and capacitors constituting pixel circuit parts that output driving currents to the light emitting elements.

The driving element layer may include gate lines, data lines, power lines, gate control lines, fan-out lines connecting the display driver200and the data lines, lead lines connecting the display driver200and the display pads DP, etc. The driving element layer may include transistors and capacitors constituting the gate driving part, and gate control lines. The driving element layer may include conductive layers, semiconductor layers, and insulating layers, and transistors, capacitors, a combination of which may constitute signal lines and/or may insulate elements.

The light emitting element layer may be positioned on the driving element layer and may include light emitting elements and light emitting regions corresponding thereto. The light emitting element layer may include a pixel definition layer having openings defining light emitting regions.

The encapsulation layer (also referred to as a thin film encapsulation layer) may cover or overlap the upper and side surfaces of the light emitting element layer, and may prevent moisture or oxygen from penetrating into the light emitting element layer from the outside. The encapsulation layer may include at least one inorganic layer and/or at least one organic layer.

The touch sensing part may include an encapsulation layer, and may include sensing electrodes TSE1and TSE2. The sensing electrodes TSE1and TSE2may sense a user's touch by a mutual capacitor method and/or a self-capacitor method.

The reflection reduction layer ARL can reduce the amount of light incident on the display panel100from the outside and reflected by the display panel100.

The reflection reduction layer ARL may include a polarization layer. The reflection reduction layer ARL may include a combination of a color filter and a light blocking member instead of a polarization layer.

The protective film PF may be attached to the rear surface of the substrate SB and may protect the display panel100during the manufacturing process of the display device30. The protective film PF may not be positioned on the bent portion BP of the sub-area SA. A bending protection layer BPL (or a stress neutralization layer) may be positioned on the bending portion BP to relieve stress of a wire positioned in the bending portion BP.

The protective sheet PS may be attached to the rear surface of the protective film PF, and may protect the display panel100from an environment on the rear surface of the display panel100(e.g., impact, electromagnetic waves, heat or noise). The protective sheet PS may be positioned in the main area MA, and may not be positioned in the sub-area SA. The protective sheet PS may have a structure in which a shielding layer SDL, a support layer SPL, and a cushion layer CSL are stacked each other.

The shielding layer SDL may prevent electromagnetic interference (EMI) or the like from flowing into the display panel100from the rear surface of the display panel100. The shielding layer SDL may be a metal layer including a metal having excellent thermal conductivity as well as shielding performance, such as copper or aluminum.

The support layer SPL may be provided to secure strength of the protection sheet PS and couple/separate the cushion layer CSL with/from other layers or members. For example, the support layer SPL may be a plastic layer made of a polymer such as polyethylene terephthalate (PET) or polyimide (PI).

The cushion layer CSL may absorb shock and prevent the display panel100from being damaged. For example, the cushion layer CSL can prevent damage to the display panel100caused by external shock and can relieve shock and stress in case that the electronic device1is dropped. The cushion layer CSL may be a porous layer formed of a material such as polyurethane or polyethylene. The cushion layer CSL may include a foam resin.

An adhesive layer such as pressure sensitive adhesive PSA may be positioned between the shielding layer SDL and the support layer SPL, and between the support layer SPL and the cushion layer CSL to attach them. The protective sheet PS may further include functional layers such as a light blocking layer and a heat dissipation layer in addition to the above-described layers.

FIGS.6and7are drawings schematically illustrating a flexible printed circuit board in the display device according to an embodiment.

InFIGS.6and7, the flexible printed circuit board300may include a body310, a pressing portion320, a tail330, a connector340, and/or a bypass portion350.FIG.6illustrates a state before the bypass portion350is bent, andFIG.7illustrates a state after the bypass portion350is bent.

The body310may have a multi-layered structure as a portion where wires are disposed in the flexible printed circuit board300. For example, the body310may include two or more layers, three or more layers, or four or more conductive layers. The conductive layers may include, for example, a conductive layer including a wire that transmits digital video data, a conductive layer including a wire that transmits power, a conductive layer including a ground layer, a conductive layer including terminals on which components are mounted, or the like. The touch driver400may be mounted on the body310. Components such as capacitors, resistors, inductors, transistors, and power modules may be mounted on the body310. The body310may occupy the largest area of the flexible printed circuit board300and may have a substantially quadrangular planar shape as a whole. Depending on the display device30, the body310may have a recessed portion on at least one side thereof in a plan view, or may have a hole formed therein.

The pressing portion320may be positioned along one edge of the body310. The pressing portion320may overlap the pad area PA of the display panel100with an electrical and physical connection member such as an anisotropic conductive layer interposed therebetween. The pressing portion320may be compressed by a pressing tool and may be bonded to the pad area PA of the panel100. Pads may be positioned on a surface of the pressing portion320, and the pads of the pressing portion320may be electrically connected to wires of the body310. Pads of the pressing portion320may be electrically connected to pads positioned in the pad area PA of the display panel100by a connecting member. The pressing portion320may include one or more conductive layers. The conductive layer of the pressing portion320may include pads. The number of conductive layers included in the pressing portion320may be less than the number of conductive layers included in the body310. For example, the pressing portion320may include one or two conductive layers, and the body310may include four or more conductive layers.

The tail330may extend from the body310. The tail330may extend substantially in the first direction DR1from one of the four sides of the body310. The tail330may include at least one conductive layer. The conductive layer of the tail330may include a wire, and the wire of the tail330may electrically connect the body310and the connector340. The number of conductive layers included in the tail330may be less than the number of conductive layers included in the body310. For example, the tail330may include one or two conductive layers, and the body310may include four or more conductive layers. The tail330may be substantially straight on a plane, but may be bent one or more times.

The connector340may be positioned at an edge of the tail330. The connector340may include connection terminals connected to wires of the tail330. The connector340may be connected to an external device such as a graphic system, a power system, or the like to receive digital video data. The connector340may receive power. Signals and power applied through the connector340may be transferred to wires disposed in the body310through wires disposed in the tail330.

The bypass portion350as a whole may have a planar shape such as “⊏”. The bypass portion350may be bent two or more times. The bypass portion350may include leg portions351and352and a connection portion353. The leg portions351and352may include a first leg portion351extending from one side of the body310and a second leg portion352extending from another side of the body310. A portion of the first leg portion351connected to the body310may be one end of the bypass portion350, and a portion of the second leg portion352connected to the body310may be another end of the bypass portion350. The first leg portion351and the second leg portion352may respectively extend from one edge and another edge of one of the four sides of the body310in the same direction—for example, in the second direction DR2. The first leg portion351and the second leg portion352may extend on a side different from the side where the tail330extends among the four sides of the body310. The connection portion353may be connected between the first leg portion351and the second leg portion352. For example, one end of the connection portion353may be connected to the first leg portion351and another end of the connection portion353may be connected to the second leg portion352. The connection portion353may be integral with the first leg portion351and the second leg portion352.

The connection portion353may extend substantially in the first direction DR1.

The connection portion353may extend substantially parallel to the pressing portion320. As the bypass portion350is formed in this way, the flexible printed circuit board300may include an opening OP or a slit formed between the body310and the bypass portion350. A planar shape of the opening OP may be approximately a “⊏” shape.

The bypass portion350may include at least one conductive layer. The conductive layer of the bypass portion350may include wires, and the wires of the bypass portion350may be electrically connected to the wires of the body310. The wires of the bypass portion350may transmit a signal sensitive to noise or a signal that may affect such a sensitive signal. For example, the wire of the bypass portion350may transmit a touch driving signal and/or a touch detection signal (hereinafter simply referred to as a touch signal). When a touch signal output from the touch driver400and input to the touch driver400interferes with other signals (e.g., digital video data or a power signal), an error in touch detection may occur, such as a ghost touch. Bypassing these sensitive signals through the bypass portion350may be advantageous in preventing interference with wires transmitting other signals. Since the number of layers of the flexible printed circuit board300can be reduced, the thickness of the flexible printed circuit board300can be partially reduced, and the manufacturing cost of the flexible printed circuit board300can be reduced. As another example, a touch signal may be transmitted through a wire of the body310, and a power signal, digital video data, and the like may be transmitted through a wire of the bypass portion350.

The number of conductive layers included in the bypass portion350may be equal to or less than the number of conductive layers included in the pressing portion320. For example, the bypass portion350may include two conductive layers, and the pressing portion320may include one or two conductive layers. The number of conductive layers included in the bypass portion350may be less than the number of conductive layers included in the body310. For example, the bypass portion350may include one or two conductive layers, and the body310may include four or more conductive layers.

The bypass portion350may be bent as shown inFIG.7, and the connection portion353may be attached to the body310. The connection part353may be attached to a surface of the body310on which the touch driver400is mounted. As another example, the connection part353may be attached to a surface of the body310on which the touch driver400is not mounted. A portion of the first leg portion351and a portion of the second leg portion352may be bent so that the bypass portion350is bent. The bypass portion350may be bent so as not to protrude beyond the pressing portion320in the second direction DR2. As the bypass portion350is bent, it may be possible to prevent the planar area of the flexible printed circuit board300from increasing due to the bypass portion350. Bending and attaching the bypass portion350may be performed before, during, or after bonding of the flexible printed circuit board300to the display panel100.

FIGS.8A and8Bare perspective views schematically illustrating a flexible printed circuit board according to a comparative example and a flexible printed circuit board according to an embodiment, respectively.

Referring toFIGS.8A and8B, a flexible printed circuit board300′ according to the comparative example includes a body310′, a pressing portion320′, a tail330′, and a connector340′. Compared to the flexible printed circuit board300according to an embodiment, the flexible printed circuit board300′ may not include a portion corresponding to the bypass portion350. Instead, the body310′ of the flexible printed circuit board300′ may have a greater number of layers and a greater thickness than the body310of the flexible printed circuit board300. For example, the body310′ may have six layers, and the body310may have four layers.

Referring toFIG.8A, signals related to a touch among signals input through the connector340′ in the flexible printed circuit board300′ may be transmitted to the touch driver400through a wire W1disposed on the tail330′ and the body310′. Signals related to video display among signals input through the connector340′ can be transmitted to the pads in a display pad region D-PA through a wire W2positioned in the tail330′ and the body310′. The touch driver400may be connected to pads of a first touch pad region T-PA1through a wire W3disposed on the body310′ and may be connected to pads of a second touch pad region T-PA2through a wire W4disposed on the body310′. Here, the display pad region D-PA, the first touch pad region T-PA1, and the second touch pad region T-PA2may correspond to the aforementioned display pad area DPA, the first touch pad area TPA1, and the second touch pad area TPA2, and pads positioned in the display pad region D-PA, the first touch pad region T-PA1, and the second touch pad region T-PA2may be connected to pads positioned in the display pad area DPA, the first touch pad area TPA1, and the second touch pad area TPA2, respectively. The wire W4connecting the touch driver400and the second touch pad region T-PA2may be positioned on a different conductive layer from the wire W2connecting the connector340′ and the display pad region D-PA, and the wires W4and W2can overlap each other. In order to prevent interference of signals transmitted through the wires W2and W4, a ground layer may be disposed between the wires W2and W4to shield them. Since a conductive layer forming or including a ground layer for preventing signal interference is required, it may be difficult to reduce the number of layers of the flexible printed circuit board300′.

Referring toFIG.8B, signals related to a touch among signals input through the connector340in the flexible printed circuit board300may be transmitted to the touch driver through a wire W1disposed in or on the tail330and the body310. Signals related to image display among signals input through the connector340may be transmitted to the pads in the display pad region D-PA through the wire W2arranged in or on the tail330and the body310. The touch driver400may be connected to the pads of the first touch pad region T-PA1through a wire W3disposed on the body310, and may be connected to the pads of the second touch pad region T-PA2through the wire W4disposed in or on the body310and the bypass portion350. One of the wires W3and W4may transmit a touch driving signal, and the other may transmit a touch sensing signal. Since the wire W4connecting the touch driver400and the second touch pad region T-PA2may be bypassed by the bypass portion350, the wire W4may not overlap the wire W2. Therefore, since the body310does not have to include a ground layer for preventing interference of signals transmitted through the wires W2and W4, the number of layers may be reduced compared to the flexible printed circuit board300′ according to the comparative example.

FIGS.9and10each schematically illustrate a cross-sectional structure of a flexible printed circuit board according to an embodiment in a state in which a bypass portion is bent.

Referring toFIGS.9and10, a laminated structure of the flexible printed circuit board300shown inFIG.5is shown. As shown inFIG.5, the direction of the flexible printed circuit board300may be based on a state in which the flexible printed circuit board300is bonded to the display panel100and the sub-area SA is bent. The flexible printed circuit board300may include first to fourth conductive layers L1-L4. The first and second conductive layers L1and L2may be formed on sides of a base film BF1, and the third and fourth conductive layers L3and L4may be formed on sides of a base film BF2. The first to fourth conductive layers L1-L4may include a metal such as copper, and the base films BF1and BF2may include a polymer such as polyimide. In this way, by forming the conductive layers L1-L4on the sides of the base films BF1and BF2, the wire density per unit area can be increased. Unlike the illustration, the conductive layer may be formed on only one side of the base films BF1and BF2. A unit in which first and second conductive layers L1and L2are formed on the sides of the base film BF1and a unit in which third and fourth conductive layers L3and L4are formed on the sides of the base film BF2may be laminated by an adhesive layer AL.

The body310may include all of the first to fourth conductive layers L1-L4. The pressing portion320including a pad PD may include first and second conductive layers L1and L2as shown inFIG.9or third and fourth conductive layers L3and L4as shown inFIG.10. The bypass portion350and the pressing portion320may include a same conductive layer. The bypass portion350may include the first and second conductive layers L1and L2as illustrated inFIG.9, or may include the third and fourth conductive layers L3and L4as illustrated inFIG.10.

The bypass portion350may be bent so that at least a portion of the bypass portion350(particularly the connection portion353) may be positioned under the fourth conductive layer L4of the body310. Since the second conductive layer L2or the fourth conductive layer L4of the bypass portion350is adjacent to and overlaps the fourth conductive layer L4of the body310, a shielding layer SL may be positioned between the bypass portion350and the body310to prevent interference between the fourth conductive layer L4of the body310and the second conductive layer L2or the fourth conductive layer L4of the bypass portion350. The shielding layer SL may include a metal layer such as a copper layer. To block external noise, the shielding layer SL may be positioned on the first conductive layer L1of the body310. To fix the position of the bent bypass portion350, the bypass portion350may be attached to the shielding layer SL.

In the bypass portion350shown inFIG.9, the second conductive layer L2relatively adjacent to the body310may include a wire that transmits a touch signal, etc., and the first conductive layer L1positioned relatively far away from the body310may include a ground layer that blocks external noise. Similarly, in the bypass portion350shown inFIG.10, the fourth conductive layer L4may include a wire transmitting a touch signal, etc., and the third conductive layer L3may include a ground layer blocking external noise.

By bending the bypass portion350, the body310may have a six-layered structure in some areas. However, since a typical 6-layer flexible printed circuit board requires that three units having conductive layers formed on sides of a base film be laminated, two lamination processes may be required. Since the flexible printed circuit board300according to the embodiment requires only one lamination process, it may be possible to reduce processes and costs in manufacturing the flexible printed circuit board300. In a typical 6-layer flexible printed circuit board, components such as the touch driver400may be mounted on the 6-layer body, but in the flexible printed circuit board300according to the embodiment, components may be mounted on a 4-layer body. Thus, the overall thickness of the flexible printed circuit board300and components mounted thereon can be reduced, and the thickness of the electronic device1can be reduced. In addition, as described above, even if the wire W4for transmitting the touch signal is disposed on the bypass portion350and the bypass portion350overlaps the body310, the bypass portion350may be shielded from the body310by the shielding layer SL. Therefore, it may be possible to prevent noise from entering the touch signal. Therefore, the 4-layer flexible printed circuit board300according to an embodiment and the 6-layer flexible printed circuit board can perform a same function.

FIG.11is a schematic cross-sectional view taken along line A-A′ inFIG.4.

The embodiment shown inFIG.11may be different from the embodiment shown inFIG.5in the direction in which the bypass portion350of the flexible printed circuit board300is bent. The bypass portion350may be bent to be positioned between the body310and the main area MA. The bypass portion350may be bent so that at least a portion of the bypass portion350is positioned on a surface (e.g., on the body310inFIG.11) opposite to the surface of the body310on which the touch driver400is positioned. The bypass portion350may be attached to the body310. Since the bypass portion350is sandwiched between the body310and the double-sided adhesive tape DST that attaches the body310to the main region MA, the double-sided adhesive tape DST can press the bypass portion350to keep the bypass portion350bent.

FIGS.12and13each schematically illustrate a cross-sectional structure of a flexible printed circuit board according to an embodiment in a state in which a bypass portion is bent.

Referring toFIGS.12and13, a laminated structure of the flexible printed circuit board300shown inFIG.11is shown. As shown inFIG.11, the direction of the flexible printed circuit board300may be based on a state in which the flexible printed circuit board300is bonded to the display panel100and the sub-area SA is bent, and the circuit board300may include first to fourth conductive layers L1-L4. The flexible printed circuit board300can have a structure in which units in each of which first and second conductive layers L1and L2are formed on sides of a base film BF1and units in which third and fourth conductive layers L3and L4are formed on sides of abase film BF2are laminated by an adhesive layer AL. The embodiments shown inFIGS.12and13may be different from the embodiments shown inFIGS.9and10in the direction in which the bypass portion350is bent. For example, the bypass portion350may be bent so that at least a portion of the bypass portion350(particularly, the connection portion353) may be positioned on the first conductive layer L1of the body310. Since the third conductive layer L3or the first conductive layer L1of the bypass portion350is adjacent to and overlaps the first conductive layer L1of the body310, a shielding layer SL may be positioned between the bypass portion350and the body310to prevent interference between the first conductive layer L1of the body310and the third conductive layer L3or the first conductive layer L1of the bypass portion350. To block external noise, a shielding layer SL may be positioned under the fourth conductive layer L4of the body310. To fix the position of the bent bypass portion350, the bypass portion350may be attached to the shielding layer SL. The shielding layer SL between the bypass portion350and the body310may be a double-sided tape having an adhesive layer on sides thereof.

In the bypass portion350shown inFIG.12, the third conductive layer L3may include a wire for transmitting a touch signal and the like, and the fourth conductive layer L4may include a ground layer for blocking external noise. Similarly, in the bypass portion350positioned inFIG.12, the second conductive layer L2may include wires for transmitting touch signals, and the first conductive layer L1may include a grounding layer that blocks external noise.

By configuring the flexible printed circuit board300in this way, even though it may be a 4-layer flexible printed circuit board300, the 4-layer flexible printed circuit board300and the 6-layer flexible printed circuit board can perform a same function, and the manufacturing process and manufacturing cost of the flexible printed circuit board can be reduced.

Although embodiments in which the body310of the flexible printed circuit board300may be four layers and the bypass portion350may have two layers have been described, the number of layers may be variously changed. For example, the body310may have two, three, five, or six layers, and the bypass portion350may have one layer or three layers. The number of layers of the bypass portion350may be designed to be smaller than the number of layers of the body310so that components can be firmly mounted on the body310and the bypass portion350can be easily bent.

FIG.14is a schematic cross-sectional view of a display device according to an embodiment.

Referring toFIG.14, the cross-sectional structure of the display device30will be described in more detail. The display panel100of the display device30may include a display part DU, a touch sensing part TSU, a protective film PF, and the like. The reflection reduction layer ARL on the touch sensing part TSU and the protective sheet PS under the protective film PF, which have been described with reference toFIG.5, are not illustrated.

The display part DU may include a substrate SB, a driving element layer DDL, a light emitting element layer EEL, and/or an encapsulation layer TFE.

The substrate SB may be a flexible or rigid substrate. The substrate SB may include one or more polymer layers and at least one barrier layer. The barrier layer may include an inorganic insulating material such as silicon nitride (SiNx), silicon oxide (SiOx), or silicon oxynitride (SiOxNy), and may prevent penetration of moisture, oxygen, and the like.

The driving element layer DDL includes a first buffer layer BL1, a lower metal layer BML, a second buffer layer BL2, a transistor TR, a gate insulating layer GI, a first interlayer insulating layer ILD1, a capacitor electrode CPE, a second interlayer insulating layer ILD2, a first connection electrode CNE1, a first passivation layer PAS1, a second connection electrode CNE2, a second passivation layer PAS2, and/or the like.

The first buffer layer BL1may be positioned on the substrate SB, the lower metal layer BML may be positioned on the first buffer layer BL1, and the second buffer layer BL2may cover or overlap the lower metal layer BML.

The transistor TR may be positioned on the second buffer layer BL2. The transistor TR may be a driving transistor or a switching transistor of the pixel circuit part. The transistor TR may include a semiconductor layer ACT and a gate electrode GE.

The semiconductor layer ACT may be positioned on the second buffer layer BL2. The semiconductor layer ACT may overlap the lower metal layer BML. The semiconductor layer ACT may include a first region, a second region, and a channel region between these regions. The semiconductor layer ACT may include a semiconductor material such as an oxide semiconductor, amorphous silicon, or polycrystalline silicon. For example, the semiconductor layer ACT may include low-temperature polycrystalline silicon (LTPS) or an oxide semiconductor material including at least one of zinc (Zn), indium (In), gallium (Ga), and tin (Sn). For example, the semiconductor layer ACT may include indium-gallium-zinc oxide (IGZO).

The first region and the second region may be regions in which the semiconductor material is conductive in the semiconductor layer ACT.

The gate electrode GE may be positioned on the gate insulating layer GI and may overlap the channel region of the semiconductor layer ACT. The gate insulating layer GI may cover the semiconductor layer ACT and insulate the semiconductor layer ACT from the gate electrode GE.

The first interlayer insulating layer ILD1may cover the gate electrode GE. The capacitor electrode CPE may be positioned on the first interlayer insulating layer ILD1. The capacitor electrode CPE may overlap the gate electrode GE. The capacitor electrode CPE and the gate electrode GE may constitute a capacitor. The second interlayer insulating layer ILD2may cover the capacitor electrode CPE.

The bottom metal layer BML, the gate electrode GE, and the capacitor electrode CPE may include, e.g., molybdenum (Mo), aluminum (Al), copper (Cu), titanium (Ti), and the like, and can be a single layer or multiple layers. Each of the first buffer layer BL1, the second buffer layer BL2, the gate insulating layer GI, the first interlayer insulating layer ILD1, and the second interlayer insulating layer ILD2may include an inorganic insulating material such as silicon nitride, silicon oxide, silicon oxynitride, or the like, and it may be a single layer or multiple layers.

The first connection electrode CNE1may be positioned on the second interlayer insulating layer ILD2and may be connected to the first region of the semiconductor layer ACT through a contact hole formed in the gate insulating layer GI, the first interlayer insulating layer ILD1, and the second interlayer insulating layer ILD2. The first passivation layer PAS1may cover or overlap the first connection electrode CNE1.

The second connection electrode CNE2may be positioned on the first passivation layer PAS1, and may be connected to the first connection electrode CNE1through a contact hole formed in the first passivation layer PAS1. The second passivation layer PAS2may cover the second connection electrode CNE2.

Each of the first connection electrode CNE1and the second connection electrode CNE2may include, e.g., aluminum (Al), platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), calcium (Ca), molybdenum (Mo), titanium (Ti), tungsten (W), copper (Cu), etc., and may be a single layer or multiple layers. Each of the first passivation layer PAS1and the second passivation layer PAS2may include an organic insulating material such as a general-purpose polymer such as poly(methyl methacrylate) and polystyrene, a polymer derivative having a phenolic group, an acrylic polymer, an imide-based polymer (e.g., polyimide), a siloxane-based polymer, etc.

The light emitting element layer EEL may be positioned on the driving element layer DDL. The light emitting element layer EEL may include a light emitting element ED and a pixel definition layer PDL. The light emitting element ED may include a pixel electrode AE, an emission layer EL, and a common electrode CE. The light emitting element ED may further include a functional layer FL including at least one of a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer. The functional layer FL may include a portion positioned between the pixel electrode AE and the emission layer EL and a portion positioned between the emission layer EL and the common electrode CE.

The pixel electrode AE may be positioned on the second passivation layer PAS2and connected to the second connection electrode CNE2through a contact hole formed in the second passivation layer PAS2. Accordingly, the pixel electrode AE may be electrically connected to the first region of the semiconductor layer ACT of the transistor TR, and may receive a driving current through the transistor TR. The pixel electrode AE may be formed of a reflective conductive material or a semi-transmissive conductive material, or may also be formed of a transparent conductive material. For example, the pixel electrode AE may include a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). The pixel electrode AE may include, e.g., a metal or metal alloy such as lithium (Li), calcium (Ca), aluminum (Al), silver (Ag), magnesium (Mg), or gold (Au). The pixel electrode AE may have a multilayer structure, for example, a triple layer structure such as ITO/silver (Ag)/ITO.

The emission layer EL may be positioned on the pixel electrode AE. For example, the emission layer EL may be an organic emission layer made of an organic material. The portion of the functional layer FL positioned between the emission layer EL and the pixel electrode AE may include a hole injection layer and/or a hole transport layer, and the portion of the functional layer FL positioned between the emission layer EL and the common electrode CE may include an electron transport layer and/or an electron injection layer.

The common electrode CE may be positioned on the emission layer EL. The common electrode CE may constitute a light emitting element ED such as an organic light emitting diode or an inorganic light emitting diode together with the pixel electrode AE and the emission layer EL. The pixel electrode AE may be an anode of the light emitting element ED, and the common electrode CE may be a cathode of the light emitting element ED. The common electrode CE may have light transmittance by having a thin layer of a metal or a metal alloy with a low work function such as calcium (Ca), barium (Ba), magnesium (Mg), aluminum (Al), or silver (Ag). The common electrode CE may include a transparent conductive oxide such as indium tin oxide (ITO) or indium zinc oxide (IZO). A low-potential power supply voltage (or common voltage) may be applied to the common electrode CE.

The pixel definition layer PDL may be positioned on the second passivation layer PAS2and may cover an edge of the pixel electrode AE. The pixel definition layer PDL may include openings OPE1, OPE2, and OPE3overlapping the pixel electrode AE. The openings OPE1, OPE2, and OPE3of the pixel definition layer PDL may define light emitting regions EA1, EA2, and EA3, and their areas or sizes may be different from each other. The light emitting regions EA1, EA2, and EA3may include a first light emitting region EA1, a second light emitting region EA2, and a third light emitting region EA3emitting different colors. For example, the first light emitting region EA1can emit red light, the second light emitting region EA2can emit green light, and the third light emitting region EA3can emit blue light. The pixel definition layer PDL may be a black pixel definition layer including a color pigment such as a black pigment or a blue pigment. For example, the pixel definition layer PDL may include a polyimide binder and a mixture of red, green, and blue pigments. For example, the pixel definition layer PDL may include a cardo binder resin and a mixture of black and blue pigments. The pixel definition layer PDL may include carbon black. The black pixel definition layer can improve the contrast ratio and prevent reflection by the underlying metal layer.

The encapsulation layer TFE may be positioned on the common electrode CE to cover the light emitting elements ED. The encapsulation layer TFE may encapsulate the light emitting element layer EEL to prevent penetration of moisture or oxygen from the outside. The encapsulation layer TFE may be a thin film encapsulation layer including one or more inorganic layers and at least one organic layer. For example, the encapsulation layer TFE may have a triple layer structure of a first inorganic layer IL1, an organic layer OL, and a second inorganic layer IL2. The first inorganic layer IL1may cover the common electrode CE and prevent penetration of moisture or oxygen into the light emitting elements ED. The organic layer OL may cover surface curvature of the first inorganic layer IL1or particles present on the first inorganic layer IL1. The organic layer OL may block the influence of the surface state of the first inorganic layer IL1on the components formed on the organic layer OL. The organic layer OL may relieve stress between the contacting layers. The second inorganic layer IL2may cover the organic layer OL. The second inorganic layer IL2may prevent moisture or the like from being released from the organic layer OL. The first inorganic layer IL1and the second inorganic layer IL2may include an inorganic material such as silicon oxide, silicon nitride, silicon oxynitride, aluminum oxide, titanium oxide, tantalum oxide, hafnium oxide, or zinc oxide. The organic layer OL may include an organic material such as acrylic resin, epoxy resin, polyimide, or polyethylene.

The touch sensing part TSU may include sensing electrodes TSE1and TSE2and insulating layers TSI1, TSI2, and TSI3positioned on at least one side of the sensing electrodes TSE1and TSE2. The sensing electrodes TSE1and TSE2may be insulated with the insulating layer TSI2interposed therebetween, and portions thereof may be electrically connected through a contact hole formed in the insulating layer TSI2. The sensing electrodes TSE1and TSE2may be electrically connected to the touch driver400of the display device30shown inFIG.2. The touch driver400may supply a touch driving signal to the sensing electrodes TSE1and TSE2and detect a change in capacitance between the sensing electrodes TSE1and TSE2. The sensing electrodes TSE1and TSE2may include, e.g., aluminum (Al), copper (Cu), silver (Ag), gold (Au), molybdenum (Mo), titanium (Ti), tantalum (Ta), and the like, and may be a single layer or multiple layers. The insulating layers TSI1, TSI2, and TSI3may include an inorganic insulating material and/or an organic insulating material.

An overcoat layer OC may be positioned on the touch sensing part TSU. The overcoat layer OC may planarize the upper surface of the display panel100. The overcoat layer OC may include a colorless light-transmissive organic material such as an acrylic resin.

FIG.15is a schematic cross-sectional view of a display device according to an embodiment.

FIG.15illustrates a structure in which a reflection reduction layer ARL is positioned on the touch sensing part TSU, compared to the embodiment ofFIG.14. The reflection reduction layer ARL may include a light blocking member BM and color filters CF (e.g., CF1, CF2, and CF3). The reflection reduction layer ARL may be covered by an overcoat layer OC.

The light blocking member BM may be positioned on the touch sensing part TSU. The light blocking member BM may include openings OPT1, OPT2, and OPT3overlapping the emission regions EA1, EA2, and EA3. The area or size of each of the openings OPT1, OPT2, and OPT3may be greater than that of corresponding openings OPE1, OPE2, and OPE3of the pixel definition layer PDL. As the openings OPT1, OPT2, and OPT3of the light blocking member BM are formed larger than the openings OPE1, OPE2, and OPE3of the pixel definition layer PDL, light may be emitted from the light emitting regions EA1, EA2, and EA3, and the light may be emitted not only in the front direction of the display device30but also in the side direction. The light blocking member BM may include a light absorbing material. For example, the light blocking member BM may include an inorganic black pigment or an organic black pigment. The inorganic black pigment may be carbon black, and the organic black pigment may include lactam black, perylene black, and/or aniline black. The light blocking member BM may improve color reproducibility of the display device30by preventing color mixing due to visible light penetrating between the first to third light emitting regions EA1, EA2, and EA3.

The color filters CF1, CF2, and CF3may be positioned on the light blocking member BM. The color filters CF1, CF2, and CF3may be disposed to correspond to the light emitting regions EA1, EA2, and EA3. For example, the first color filter CF1may overlap the first opening OPE1of the pixel definition layer PDL and the first opening OPT1of the light blocking member BM, the second color filter CF2may overlap the second opening OPE2of the pixel definition layer PDL and the second opening OPT2of the light blocking member BM, and the third color filter CF3may overlap the third opening OPE3of the pixel definition layer PDL and the third opening OPT3of the light blocking member BM. Each of the color filters CF1, CF2, and CF3may be disposed to have a larger area in a plan view than the corresponding openings OPT1, OPT2, and OPT3of the light blocking member BM, and a portion of each color filter CF1, CF2, and CF3may overlap the light blocking member BM. An overlapping portion OLP where adjacent color filters CF1, CF2, and CF3overlap each other may be positioned on the light blocking member BM. The color filters CF1, CF2, and CF3may include a colorant such as a dye or pigment that absorbs light in a wavelength range other than a specific wavelength range, and emits light from the light emitting regions EA1, EA2, and EA3, and it can be disposed corresponding to the color of the light. For example, the first color filter CF1may be a red color filter that transmits only red light, the second color filter CF2may be a green color filter that transmits only green light, and the third color filter CF3may be a blue color filter that transmits only blue light. In the reflection reduction layer ARL, the color filters CF1, CF2, and CF3may transmit light of a specific wavelength and block or absorb light of other wavelengths, and the light blocking member BM may absorb external light. Accordingly, the amount of light introduced from the outside into the display device30may be reduced, and the amount of light reflected by the display device30may also be reduced, thereby reducing drawbacks caused by reflection of external light. The overcoat layer OC may cover the color filters CF1, CF2, and CF3and planarize the upper surface of the display panel100. As the reflection reduction layer ARL, a polarization layer may be included instead of a combination of the color filters CF1, CF2, and CF3and the light blocking member BM.