KR20210034335A - Flexible display - Google Patents

Abstract

According to an embodiment of the present invention, provided is a flexible display device which can simplify a process. The flexible display device comprises: a lower substrate including a plurality of grooves; a light blocking layer formed in the plurality of grooves and made of liquid metal; a transistor disposed on the light blocking layer; and an organic light emitting element disposed on the transistor.

Description

Flexible display device {FLEXIBLE DISPLAY}

The present invention relates to a flexible display device.

As information technology develops, the market for display devices, which is a connection medium between users and information, is growing. Accordingly, the use of display devices such as an organic light emitting display (OLED), a liquid crystal display (LCD), and a plasma display panel (PDP) is increasing.

Among them, since the organic light emitting device display is a self-luminous device, power consumption is lower than that of a liquid crystal display device requiring a backlight and can be manufactured to be thinner. In addition, the OLED display device has an advantage in that the viewing angle is wide and the response speed is fast. The organic light emitting diode display is expanding the market while competing with the liquid crystal display device as the process technology has been developed to the level of mass production technology on a large screen.

The pixels of an organic light-emitting device display device include an organic light-emitting device (hereinafter referred to as “OLED”) that is a self-luminous device. Organic light-emitting device display devices can be classified in various ways according to the type of light-emitting material, light-emitting method, light-emitting structure, driving method, and the like. The organic light emitting diode display can be divided into fluorescence emission and phosphorescence emission according to the emission method, and may be divided into a top emission structure and a bottom emission structure according to the emission structure. In addition, organic light emitting diode displays can be divided into PMOLED (Passive Matrix OLED) and AMOLED (Active Matrix OLED) according to a driving method.

In recent years, flexible display devices are commercially available. The flexible display device can reproduce an input image on a screen of a display panel on which a plastic OLED is formed. Plastic OLEDs are formed on a flexible plastic substrate (SUB). The flexible display device can implement various designs and has advantages in portability and durability. The flexible display device may be implemented in various forms, such as a bendable display device, a foldable display device, a rollable display device, and a stretchable display device. Such flexible display devices can be applied not only to mobile devices such as smartphones and tablet PCs, but also to TVs, automobile displays, and wearable devices, and their application fields are expanding.

The present invention provides a flexible display device capable of improving rigidity and flexibility and simplifying a process.

A flexible display device according to an embodiment of the present invention includes a flexible substrate including a plurality of grooves, a light blocking layer formed in the plurality of grooves and made of a liquid metal, a transistor positioned on the light blocking layer, and on the transistor. It may include an organic light emitting device positioned.

The light blocking layer, the transistor, and the organic light emitting device may overlap each other.

The light blocking layer may include a liquid layer and an oxide layer positioned on the liquid layer.

The liquid layer may be made of the liquid metal, and the oxide layer may be made of an oxide of the liquid metal.

The liquid metal may include at least two eutectic alloys selected from the group consisting of Al, Zn, Ga, Ge, Cd, In, Sn, Sb, Hg, Tl, Pb, and Bi.

The eutectic alloys include EGaln, Galinstan (Ga/In/Sn), Ga/Sn (92:8), Ga/Al (97:3), Ga/Zn (96:4) and Ga/Ag (96 It may include any one or more selected from the group consisting of :4).

The light blocking layer may be filled in the groove.

Each of the plurality of grooves may correspond to one subpixel on a one-to-one basis.

The transistor may include an active layer on the light blocking layer, a gate insulation layer on the active layer, a gate electrode on the gate insulation layer, an interlayer insulation layer on the gate electrode, and the interlayer. It may include a source electrode and a drain electrode positioned on the insulating layer.

The organic light-emitting device may include a first electrode connected to the transistor, an organic emission layer on the first electrode, and a second electrode on the organic emission layer.

The second electrode may be connected to the light blocking layer.

The second electrode may be connected to the light blocking layer through a first connection pattern and a second connection pattern positioned on the light blocking layer.

The light blocking layer, the first connection pattern, the second connection pattern, and the second electrode may overlap each other.

The first connection pattern may be located between the light blocking layer and the second connection pattern, and the second connection pattern may be located between the first connection pattern and the second electrode.

An encapsulation layer disposed on the organic light emitting device and including at least one of a UV resin layer, a silicon oxide layer, a water repellent coating layer, and an anti-fingerprint layer may be further included.

In the flexible display device according to an embodiment of the present invention, by forming a light blocking layer made of liquid metal in the groove of the flexible substrate, flexibility and rigidity are simultaneously provided to the flexible substrate, thereby increasing the flexibility of the flexible substrate. There is an advantage of being able to form a light emitting device. Accordingly, even if the flexible display device is bent or bent freely, the adhesive properties and mechanical reliability of the device can be improved.

In addition, in the flexible display device according to an exemplary embodiment of the present invention, by using a light blocking layer as an auxiliary electrode of the second electrode, it is possible to prevent luminance deviation due to a voltage drop of the second electrode from occurring.

The present invention has an effect of making the modulus of a region overlapping a plurality of pixel substrates of an upper substrate larger than a modulus of a region not overlapping with the plurality of pixel substrates, thereby enabling the flexible display device to be more easily bent or stretched.

1 is a schematic block diagram of a flexible display device.
2 is a schematic circuit configuration diagram of a subpixel.
3 is a detailed circuit configuration example of a subpixel.
4 is a schematic perspective view of a flexible display device.
5 is an exploded perspective view of a flexible display device according to a first embodiment of the present invention.
6 is an enlarged plan view of the flexible display device according to the first exemplary embodiment of the present invention.
7 is a schematic cross-sectional view of one subpixel of FIG. 5;
8 is a schematic cross-sectional view of another sub-pixel of the flexible display device according to the first exemplary embodiment of the present invention.
9 is a cross-sectional view illustrating a flexible display device according to a second exemplary embodiment of the present invention.
10 is a cross-sectional view showing a light blocking layer of the present invention.
11 is a schematic cross-sectional view of a flexible display device according to a second exemplary embodiment of the present invention.
12 to 17 are cross-sectional views showing a method of manufacturing a flexible display device according to a second embodiment of the present invention for each process.
18 is a cross-sectional view illustrating a subpixel of a flexible display device according to a third exemplary embodiment of the present invention.
19 is a schematic cross-sectional view of one sub-pixel of a flexible display device according to a fourth exemplary embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings. The same reference numbers throughout the specification mean substantially the same elements. In the following description, when it is determined that a detailed description of a known technology or configuration related to the present invention may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted. In describing various embodiments, the same components are representatively described at the beginning and may be omitted in other embodiments.

Terms including ordinal numbers such as first and second may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another component.

A flexible display device according to the present invention is a display device in which a display device is formed on a flexible substrate. As an example of the flexible display device, an organic light emitting display device, a liquid crystal display device, an electrophoretic display device, and the like can be used. In the present invention, an organic light emitting display device is described as an example. The organic light emitting display device includes an organic light emitting layer made of an organic material between a first electrode as an anode and a second electrode as a cathode. Therefore, holes supplied from the first electrode and electrons supplied from the second electrode combine in the organic emission layer to form excitons, which are hole-electron pairs, and emit light by energy generated when the excitons return to the ground state. It is a self-luminous display device.

The flexible display device according to the present invention may be a stretchable display device. The stretchable display device may be referred to as a display device capable of displaying an image even if it is bent or stretched. The stretchable display device may have high flexibility compared to a general display device. Accordingly, the shape of the stretchable display device can be freely changed according to the user's manipulation, such as bending or stretching the stretchable display device by the user. For example, when a user grabs and pulls the end of the stretchable display device, the stretchable display device may be stretched by the user's force. Alternatively, when a user arranges the stretchable display device on an uneven wall surface, the stretchable display device may be arranged to bend along the shape of the wall surface. In addition, when the force applied by the user is removed, the stretchable display device may return to its original shape again.

1 is a schematic block diagram of a flexible display device, FIG. 2 is a schematic circuit configuration diagram of a subpixel, FIG. 3 is a detailed circuit configuration example of a subpixel, and FIG. 4 is a perspective view schematically showing a flexible display device to be.

As shown in FIG. 1, the flexible display device includes an image processing unit 110, a timing controller 120, a data driver 130, a scan driver 140, and a display panel 150.

The image processing unit 110 outputs a data enable signal DE in addition to the data signal DATA supplied from the outside. In addition to the data enable signal DE, the image processing unit 110 may output one or more of a vertical synchronization signal, a horizontal synchronization signal, and a clock signal, but these signals are omitted for convenience of description.

The timing controller 120 receives a data enable signal DE or a driving signal including a vertical synchronization signal, a horizontal synchronization signal, a clock signal, and the like from the image processing unit 110 and a data signal DATA. The timing control unit 120 includes a gate timing control signal GDC for controlling the operation timing of the scan driver 140 and a data timing control signal DDC for controlling the operation timing of the data driver 130 based on the driving signal. Prints.

The data driver 130 samples and latches the data signal DATA supplied from the timing controller 120 in response to the data timing control signal DDC supplied from the timing controller 120, converts it to a gamma reference voltage, and outputs the sample. . The data driver 130 outputs a data signal DATA through the data lines DL1 to DLn. The data driver 130 may be formed in the form of an integrated circuit (IC).

The scan driver 140 outputs a scan signal in response to the gate timing control signal GDC supplied from the timing controller 120. The scan driver 140 outputs a scan signal through the gate lines GL1 to GLm. The scan driver 140 is formed in the form of an integrated circuit (IC) or is formed on the display panel 150 in a gate-in panel method.

The display panel 150 displays an image in response to a data signal DATA and a scan signal supplied from the data driver 130 and the scan driver 140. The display panel 150 includes subpixels SPX that operate to display an image.

The subpixels SPX include a red subpixel, a green subpixel, and a blue subpixel, or include a white subpixel, a red subpixel, a green subpixel, and a blue subpixel. The subpixels SPX may have one or more different light emission areas according to light emission characteristics.

As shown in FIG. 2, one subpixel includes a switching transistor SW, a driving transistor DR, a capacitor Cst, a compensation circuit CC, and an organic light emitting diode OLED.

The switching transistor SW performs a switching operation so that the data signal supplied through the data line DL is stored as a data voltage in the capacitor Cst in response to the scan signal supplied through the first gate line GL1. The driving transistor DR operates so that a driving current flows between the power line EVDD (high potential voltage) and the cathode power line EVSS (low potential voltage) according to the data voltage stored in the capacitor Cst. The organic light emitting diode OLED operates to emit light according to a driving current formed by the driving transistor DR.

The compensation circuit CC is a circuit added in the subpixel to compensate for the threshold voltage of the driving transistor DR. The compensation circuit CC is composed of one or more transistors. The configuration of the compensation circuit (CC) is very diverse according to the external compensation method, and an example thereof will be described as follows.

As shown in FIG. 3, the compensation circuit CC includes a sensing transistor ST and a sensing line VREF (or a reference line). The sensing transistor ST is connected between the source electrode of the driving transistor DR and the anode electrode of the organic light emitting diode OLED (hereinafter, a sensing node). The sensing transistor ST supplies an initialization voltage (or sensing voltage) transmitted through the sensing line VREF to the sensing node of the driving transistor DR, or the sensing node of the driving transistor DR or the voltage of the sensing line VREF. Or it operates so that it can sense the current.

In the switching transistor SW, a source electrode or a drain electrode is connected to the data line DL, and the other of the source electrode or the drain electrode is connected to the gate electrode of the driving transistor DR. In the driving transistor DR, a source electrode or a drain electrode is connected to the power line EVDD, and the other of the source electrode or the drain electrode is connected to the first electrode, which is an anode of the organic light emitting diode OLED. The capacitor Cst has a lower electrode connected to the gate electrode of the driving transistor DR, and the upper electrode connected to the anode electrode of the organic light emitting diode OLED. In the organic light emitting diode OLED, a first electrode is connected to the other of the source or drain electrode of the driving transistor DR, and a second electrode, which is a cathode electrode, is connected to the second power line EVSS. The sensing transistor ST has a source electrode or a drain electrode connected to the sensing line VREF, and a source electrode to the other of the first electrode of the organic light emitting diode OLED and the source or drain electrode of the driving transistor DR, which is a sensing node. Alternatively, the other one of the drain electrodes is connected.

The operating time of the sensing transistor ST may be similar to, the same as, or different from the switching transistor SW according to an external compensation algorithm (or a configuration of a compensation circuit). For example, the switching transistor SW may have a gate electrode connected to the first gate line GL1, and the sensing transistor ST may have a gate electrode connected to the second gate line GL2. In this case, the scan signal Scan is transmitted to the first gate line GL1 and the sensing signal Sense is transmitted to the second gate line GL2. As another example, the first gate line GL1 connected to the gate electrode of the switching transistor SW and the second gate line GL2 connected to the gate electrode of the sensing transistor ST may be connected to be shared in common.

The sensing line VREF may be connected to the data driver. In this case, the data driver may sense a sensing node of a subpixel during real time, a non-display period of an image, or a period of N frames (N is an integer greater than or equal to 1) and generate a sensing result. Meanwhile, the switching transistor SW and the sensing transistor ST may be turned on at the same time. In this case, the sensing operation through the sensing line VREF and the data output operation of outputting a data signal are separated (divided) from each other according to the time division method of the data driver.

In addition, the compensation target according to the sensing result may be a digital data signal, an analog data signal, or a gamma. In addition, a compensation circuit for generating a compensation signal (or compensation voltage) based on the sensing result may be implemented in the data driver, the timing controller, or a separate circuit.

The light blocking layer LS may be disposed only under the channel region of the driving transistor DR, or may be disposed not only under the channel region of the driving transistor DR, but also under the channel region of the switching transistor SW and the sensing transistor ST. The light blocking layer LS may be used for the purpose of simply blocking external light, or the light blocking layer LS may be used as an electrode constituting a capacitor or the like to connect with other electrodes or lines. Therefore, the light blocking layer LS is selected as a metal layer of a multilayer (multilayer of dissimilar metals) so as to have light blocking characteristics.

In addition, in FIG. 3, a subpixel having a 3T (Transistor) 1C (Capacitor) structure including a switching transistor (SW), a driving transistor (DR), a capacitor (Cst), an organic light emitting diode (OLED), and a sensing transistor (ST) is shown. Although described as an example, when the compensation circuit CC is added, it may be configured with 3T2C, 4T2C, 5T1C, 6T2C, or the like.

4 is a diagram showing an example of use of a flexible display device.

Referring to FIG. 4, the display panel PNL includes a display area AA in which an input image is implemented. The user may recognize information output from the display panel PNL through the display area AA. The display area AA may be defined on one side of the display panel PNL, and may be defined on both sides of the display panel PNL. In addition, if necessary, it may be defined limited to a specific area.

The display panel PNL may have a predetermined softness so that a rolling or winding, unrolling, or unwinding operation may be easily repeatedly performed. The display panel PNL may be wound in various directions as necessary. For example, the display panel PNL may be wound in a horizontal and/or vertical direction, or may be wound in an oblique direction. The display panel PNL may be wound in a front direction and/or a rear direction of the display panel PNL.

Alternatively, the display panel PNL may be provided with a predetermined softness, and an operation of bending or folding, unbending, or unfolding may be repeatedly performed. Alternatively, the display panel PNL may have a predetermined softness, and an operation of stretching and restoring it may be repeatedly performed.

The change in the state of the display panel PNL may be caused by a physical external force directly provided by the user. For example, the user can implement a state change of the display panel PNL by grasping one end of the display panel PNL and providing a force thereto. The state change of the display panel PNL may be controlled through a control unit in response to a preset specific signal. That is, the state change of the display panel PNL may be controlled by a selected driving device and a driving circuit.

<First Example>

5 is an exploded perspective view of a flexible display device according to a first exemplary embodiment of the present invention.

Referring to FIG. 5, the flexible display device 100 of the present invention will be described as an example of a stretchable display device. The stretchable display device 100 includes a lower substrate 110, a plurality of pixel substrates 111, a connection wiring 180, a chip on flim (COF), a printed circuit board 140, and an upper substrate 120. ) And a polarizing layer 190. In FIG. 5, the illustration of an adhesive layer for bonding the lower substrate 110 and the upper substrate 120 to each other is omitted for convenience of description.

The lower substrate 110 is a substrate for supporting and protecting various components of the stretchable display device 100. The lower substrate 110 is a flexible substrate and may be formed of an insulating material that can be bent or stretched. For example, the lower substrate 110 is made of an elastomer such as a silicone rubber such as polydimethylsiloxane (PDMS) and a polyurethane (PU), and thus has a flexible property. I can have it. However, the material of the lower substrate 110 is not limited thereto.

The lower substrate 110 is a flexible substrate, and may be reversibly expanded and contracted. In addition, the elastic modulus may be several MPa to several hundred MPa, and the elongation failure rate may be 100% or more. The thickness of the lower substrate may be 10 μm to 1 mm, but is not limited thereto.

The lower substrate 110 may have a display area AA and a non-display area NA surrounding the display area AA.

The display area AA is an area in which an image is displayed in the stretchable display device 100, and various driving elements for driving the display element and the display element are disposed. The display area AA includes a plurality of pixels including a plurality of subpixels. The plurality of pixels are disposed in the display area AA and include a plurality of display elements. Each of the plurality of subpixels may be connected to various wires. For example, each of the plurality of subpixels may be connected to various lines such as a gate line, a data line, a high potential power line, a low potential power line, and a reference voltage line.

The non-display area NA is an area adjacent to the display area AA. The non-display area NA is an area adjacent to the display area AA and surrounding the display area AA. The non-display area NA is an area in which an image is not displayed, and lines (or wirings) and circuit portions may be formed. For example, a plurality of pads may be disposed in the non-display area NA, and each pad may be connected to each of a plurality of subpixels of the display area AA.

A plurality of pixel substrates 111 are disposed on the lower substrate 110. The plurality of pixel substrates 111 are rigid substrates and are spaced apart from each other and disposed on the lower substrate 110. The plurality of pixel substrates 111 may be rigid compared to the lower substrate 110. That is, the lower substrate 110 may have softer characteristics than the plurality of pixel substrates 111, and the plurality of pixel substrates 111 may have more rigid characteristics than the lower substrate 110.

The plurality of pixel substrates 111, which are a plurality of rigid substrates, may be made of a plastic material having flexibility. For example, polyimide (PI), polyacrylate, polyacetate ( polyacetate) or the like.

The modulus of the plurality of pixel substrates 111 may be higher than that of the lower substrate 110. The modulus is an elastic modulus representing the ratio of deformation by stress to the stress applied to the substrate. When the modulus is relatively high, the hardness may be relatively high. Accordingly, the plurality of pixel substrates 111 may be a plurality of rigid substrates having rigidity compared to the lower substrate 110. The modulus of the plurality of pixel substrates 111 may be 1000 times or more greater than the modulus of the lower substrate 110, but is not limited thereto.

A connection wiring 180 is disposed between the plurality of pixel substrates 111. The connection wiring 180 may be disposed between pads disposed on the plurality of pixel substrates 111 to electrically connect each pad. A more detailed description of the connection wiring 180 will be described in detail with reference to FIG. 6.

The COF 130 is a film in which various components are arranged on the flexible base film 131 and is a component for supplying signals to a plurality of subpixels in the display area AA. The COF 130 may be bonded to a plurality of pads disposed in the non-display area NA, and supplies a power voltage, a data voltage, and a gate voltage to each of the plurality of subpixels of the display area AA through the pads. . The COF 130 includes a base film 131 and a driving IC 132, and various other components may be disposed.

The base film 131 is a layer supporting the driving IC 132 of the COF 130. The base film 131 may be made of an insulating material, for example, may be made of an insulating material having flexibility.

The driving IC 132 is a component that processes data for displaying an image and a driving signal for processing the data. In FIG. 5, the driving IC 132 is shown to be mounted in the COF 130 method, but is not limited thereto, and the driving IC 132 is mounted in a method such as COG (Chip On Glass), TCP (Tape Carrier Package), etc. It could be.

A control unit such as an IC chip and a circuit unit may be mounted on the printed circuit board 140. In addition, a memory, a processor, etc. may be mounted on the printed circuit board 140. The printed circuit board 140 is a component that transmits a signal for driving a display device from a controller to a display device.

The printed circuit board 140 may be connected to the COF 130 to be electrically connected to each of the plurality of subpixels of the plurality of pixel substrates 111.

The upper substrate 120 is a substrate for protecting various components of the stretchable display device 100 by overlapping with the lower substrate 110. The upper substrate 120 is a flexible substrate and may be formed of an insulating material that can be bent or stretched. For example, the upper substrate 120 may be made of a material having flexibility, and may be made of the same material as the lower substrate 110, but is not limited thereto.

The polarizing layer 190 is a component that suppresses reflection of external light from the stretchable display device 100 and may be disposed on the upper substrate 120 to overlap the upper substrate 120. However, the present invention is not limited thereto, and the polarization layer 190 may be disposed under the upper substrate 120 or may be omitted depending on the configuration of the stretchable display device 100.

Hereinafter, for a more detailed description of the stretchable display device 100 according to the first embodiment of the present invention, reference will be made to FIGS. 6 and 7 together.

6 is an enlarged plan view of a stretchable display device according to the first exemplary embodiment of the present invention. 7 is a schematic cross-sectional view of the subpixel of FIG. 5. For convenience of explanation, it will be described with reference to FIG. 5.

6 and 7, a plurality of pixel substrates 111 are disposed on the lower substrate 110. The plurality of pixel substrates 111 are spaced apart from each other and disposed on the lower substrate 110. For example, the plurality of pixel substrates 111 may be disposed in a matrix form on the lower substrate 110 as shown in FIGS. 5 and 6, but is not limited thereto.

Referring to FIG. 3, a buffer layer 112 is disposed on a plurality of pixel substrates 111. The buffer layer 112 protects various components of the stretchable display device 100 from penetration _{of moisture (H 2} O) and oxygen (O ₂ ) from outside the lower substrate 110 and the plurality of pixel substrates 111. It is formed on the plurality of pixel substrates 111 to protect. The buffer layer 112 may be formed of an insulating material, and for example, an inorganic layer formed of silicon nitride (SiNx), silicon oxide (SiOx), silicon oxynitride (SiON), or the like may be formed as a single layer or a multiple layer. However, the buffer layer 112 may be omitted depending on the structure or characteristics of the stretchable display device 100.

In this case, the buffer layer 112 may be formed only in a region overlapping the plurality of pixel substrates 111. As described above, since the buffer layer 112 may be made of an inorganic material, the stretchable display device 100 may be easily damaged during stretching. Accordingly, the buffer layer 112 may not be formed in a region between the plurality of pixel substrates 111, but may be patterned in the shape of the plurality of pixel substrates 111 to be formed only on the plurality of pixel substrates 111. Accordingly, in the stretchable display device 100 according to the first embodiment of the present invention, the stretchable display device 100 is formed by forming the buffer layer 112 only in a region overlapping the plurality of pixel substrates 111 which are rigid substrates. Even when the buffer layer 112 is deformed, such as bending or stretching, it is possible to prevent damage to the buffer layer 112.

Referring to FIG. 7, a transistor 150 including a gate electrode 151, an active layer 152, a source electrode 153, and a drain electrode 154 is formed on the buffer layer 112. For example, an active layer 152 is formed on the buffer layer 112, and a gate insulating layer 113 for insulating the active layer 152 and the gate electrode 151 is formed on the active layer 152. . An interlayer insulating layer 114 for insulating the gate electrode 151 and the source electrode 153 and the drain electrode 154 is formed, and a source electrode ( 153 and a drain electrode 154 are formed.

In addition, the gate insulating layer 113 and the interlayer insulating layer 114 may be patterned to be formed only in a region overlapping the plurality of pixel substrates 111. The gate insulating layer 113 and the interlayer insulating layer 114 may also be made of an inorganic material in the same manner as the buffer layer 112, and thus, cracks may be easily generated during stretching of the stretchable display device 100 and may be damaged. . Accordingly, the gate insulating layer 113 and the interlayer insulating layer 114 are not formed in a region between the plurality of pixel substrates 111, but are patterned in the shape of a plurality of pixel substrates 111 to form a plurality of pixel substrates 111. It can be formed only on the top.

In FIG. 7, for convenience of explanation, only a driving transistor is illustrated among various transistors that may be included in the stretchable display device 100, but a switching transistor, a capacitor, and the like may also be included in the display device. In addition, although the transistor 150 has been described as having a coplanar structure in this specification, various transistors such as a staggered structure may also be used.

Referring to FIG. 7, a gate pad 171 is disposed on the gate insulating layer 113. The gate pad 171 is a pad for transmitting a gate signal to the plurality of subpixels SPX. The gate pad 171 may be made of the same material as the gate electrode 151, but is not limited thereto.

An overcoat layer 115 is formed on the transistor 150 and the interlayer insulating layer 114. The overcoat layer 115 flattens the upper portion of the transistor 150. The overcoat layer 115 may be composed of a single layer or a plurality of layers, and may be formed of an organic material. For example, the overcoat layer 115 may be made of an acrylic organic material, but is not limited thereto. The overcoat layer 115 includes a contact hole for electrically connecting the transistor 150 and the anode 161, a contact hole for electrically connecting the data pad 173 and the source electrode 153, and a connection pad 172 And a contact hole for electrically connecting the gate pad 171 to each other.

In some embodiments, a passivation layer may be formed between the transistor 150 and the overcoat layer 115. That is, in order to protect the transistor 150 from penetration of moisture and oxygen, a passivation layer covering the transistor 150 may be formed. The passivation layer may be made of an inorganic material, and may be made of a single layer or a multilayer, but is not limited thereto.

Referring to FIG. 7, a data pad 173, a connection pad 172, and an organic light emitting diode 160 are disposed on the overcoat layer 115.

The data pad 173 may transmit a data signal from the connection line 180 functioning as a data line to the plurality of sub-pixels SPX. The data pad 173 is connected to the source electrode 153 of the transistor 150 through a contact hole formed in the overcoat layer 115. The data pad 173 may be made of the same material as the anode 161 of the organic light emitting device 160, but is not limited thereto. In addition, the data pad 173 may be formed on the interlayer insulating layer 114, not on the overcoat layer 115, and may be formed of the same material as the source electrode 153 and the drain electrode 154 of the transistor 150. .

The connection pad 172 may transmit a gate signal from the connection line 180 functioning as a gate line to the plurality of sub-pixels SPX. The connection pad 172 is connected to the gate pad 171 through a contact hole formed in the overcoat layer 115 and the interlayer insulating layer 114, and transmits a gate signal to the gate pad 171. The connection pad 172 may be made of the same material as the data pad 173, but is not limited thereto.

The organic light-emitting device 160 is disposed to correspond to each of the plurality of sub-pixels SPX, and is a component that emits light having a specific wavelength band. That is, the organic light-emitting device 160 may be a blue organic light-emitting device that emits blue light, a red organic light-emitting device that emits red light, a green organic light-emitting device that emits green light, or a white organic light-emitting device that emits white light, but is limited thereto. It does not become. When the organic light-emitting device 160 is a white organic light-emitting device, the stretchable display device 100 may further include a color filter.

The organic light-emitting device 160 includes an anode 161, an organic light-emitting layer 162 and a cathode 163. Specifically, the anode 161 is disposed on the overcoat layer 115. The anode 161 is an electrode configured to supply holes to the organic emission layer 162. The anode 161 may be formed of a transparent conductive material having a high work function. Here, the transparent conductive material may include Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), and Indium Tin Zinc Oxide (ITZO). The anode 161 may be made of the same material as the data pad 173 and the gate pad 171 disposed on the overcoat layer 115, but is not limited thereto. In addition, when the stretchable display device 100 is implemented in a top emission method, the anode 161 may further include a reflector.

The anode 161 is disposed to be spaced apart for each sub-pixel SPX, and is electrically connected to the transistor 150 through a contact hole of the overcoat layer 115. For example, in FIG. 6, the anode 161 is shown to be electrically connected to the drain electrode 154 of the transistor 150, but may be electrically connected to the source electrode 153.

A bank 116 is formed on the anode 161, the data pad 173, the connection pad 172, and the overcoat layer 115. The bank 116 is a component that divides adjacent sub-pixels SPX. The bank 116 is disposed to cover at least a portion of both sides of the adjacent anode 161 to expose a portion of the upper surface of the anode 161. The bank 116 plays a role in preventing a problem in which the unintended sub-pixel SPX emits light or is mixed with light because the current is concentrated at the edge of the anode 161 so that light is emitted in the lateral direction of the anode 161. You can also do it. The bank 116 may be made of an acrylic (acryl)-based resin, a benzocyclobutene (BCB)-based resin, or a polyimide, but is not limited thereto.

The bank 116 includes a contact hole connecting the connection wire 180 functioning as a data wire and the data pad 173, and a contact hole connecting the connection wire 180 functioning as a gate wire and the connection pad 172 do.

The organic emission layer 162 is disposed on the anode 161. The organic emission layer 162 is configured to emit light. The organic emission layer 162 may include a light-emitting material, and the light-emitting material may include a phosphorescent material or a fluorescent material, but is not limited thereto.

The organic emission layer 162 may be formed of one emission layer. Alternatively, the organic emission layer 162 may have a stack structure in which a plurality of emission layers stacked with a charge generation layer interposed therebetween are stacked. In addition, the organic emission layer 162 may further include at least one organic layer of a hole transport layer, an electron transport layer, a hole blocking layer, an electron blocking layer, a hole injection layer, and an electron injection layer.

6 and 7, the cathode 163 is disposed on the organic emission layer 162. The cathode 163 supplies electrons to the organic emission layer 162. The cathode 163 is Indium Tin Oxide (ITO), Indium Zin Oxide (IZO), Indium Tin Zinc Oxide (ITZO), Zinc Oxide (ZnO), and tin. It may also be made of an oxide (Tin Oxide, TO)-based transparent conductive oxide or a ytterbium (Yb) alloy. Alternatively, the cathode 163 may be made of a metallic material.

The cathode 163 may be formed by patterning to overlap each of the plurality of pixel substrates 111. That is, the cathode 163 may be formed only in a region overlapping the plurality of pixel substrates 111, and may be disposed so as not to be formed in a region between the plurality of pixel substrates 111. Since the cathode 163 is made of a material such as a transparent conductive oxide, a metal material, etc., when the cathode 163 is also formed in a region between the plurality of pixel substrates 111, the process of stretching the stretchable display device 100 The cathode 163 may be damaged at. Accordingly, the cathode 163 may be formed to correspond to each of the plurality of pixel substrates 111 on a plane. 6 and 7, the cathode 163 may be formed to have an area that does not overlap an area in which the connection wiring 180 is disposed in an area overlapping the plurality of pixel substrates 111.

Unlike a general organic light emitting display device, in the stretchable display device 100 according to the exemplary embodiment of the present invention, the cathode 163 is patterned to correspond to the plurality of pixel substrates 111 and formed. Accordingly, each of the cathodes 163 disposed on the plurality of pixel substrates 111 may independently receive low-potential power through the connection wiring 180.

6 and 7, an encapsulation layer 117 is disposed on the organic light-emitting device 160. The encapsulation layer 117 may cover the organic light-emitting device 160 and contact a portion of the upper surface of the bank 116 to seal the organic light-emitting device 160. Accordingly, the encapsulation layer 117 protects the organic light-emitting device 160 from moisture, air, or physical impact that may penetrate from the outside.

The encapsulation layer 117 covers each of the patterned cathodes 163 to overlap each of the plurality of pixel substrates 111, and may be formed for each of the plurality of pixel substrates 111. That is, the encapsulation layer 117 is disposed to cover one cathode 163 disposed on one pixel substrate 111, and the encapsulation layers 117 disposed on each of the plurality of pixel substrates 111 are spaced apart from each other. I can.

The encapsulation layer 117 may be formed only in a region overlapping the plurality of pixel substrates 111. As described above, since the encapsulation layer 117 may be configured to include an inorganic layer, the stretchable display device 100 may be damaged, such as cracks easily generated during the stretching process. In particular, since the organic light-emitting device 160 is vulnerable to moisture or oxygen, if the encapsulation layer 117 is damaged, the reliability of the organic light-emitting device 160 may decrease. Accordingly, in the stretchable display device 100 according to the first exemplary embodiment of the present invention, the encapsulation layer 117 is not formed in a region between the plurality of pixel substrates 111, so that the stretchable display device 100 Damage to the encapsulation layer 117 may be minimized even when it is deformed, such as bending or stretching.

Comparing the stretchable display device 100 according to an embodiment of the present invention with a general flexible organic light emitting display device, the stretchable display device 100 has a plurality of pixel substrates 111 having relatively rigidity. It has a structure that is spaced apart and disposed on a relatively flexible lower substrate 110. In addition, the cathode 163 and the encapsulation layer 117 of the stretchable display device 100 are patterned and disposed to correspond to each of the plurality of pixel substrates 111. That is, in the stretchable display device 100 according to the first embodiment of the present invention, when the user stretches or flexes the stretchable display device 100, the stretchable display device 100 can be more easily deformed. The stretchable display device 100 may have a structure that can minimize damage to components of the stretchable display device 100 while the stretchable display device 100 is deformed.

Meanwhile, the connection wiring 180 illustrated in FIGS. 5 and 6 refers to a wiring that electrically connects pads on the plurality of pixel substrates 111. The connection wire 180 includes a first connection wire 181 and a second connection wire 182. The first connection wire 181 refers to a wire extending in the X-axis direction among the connection wires 180, and the second connection wire 182 refers to a wire extending in the Y-axis direction among the connection wires 180.

In a general organic light emitting display device, various lines (or wirings) such as a plurality of gate lines and a plurality of data lines are disposed to extend between a plurality of sub-pixels, and a plurality of sub-pixels are connected to one signal line. Accordingly, in the case of the OLED display, various lines such as a gate line, a data line, a high potential power line, and a reference voltage line extend from one side of the OLED display to the other side without interruption on the substrate.

In contrast, in the case of the stretchable display device 100 according to the first embodiment of the present invention, various lines such as a gate line, a data line, a high potential power line, a reference voltage line, etc. made of a metal material are formed of a plurality of pixel substrates. It is placed only on (111). That is, in the stretchable display device 100 according to the first embodiment of the present invention, various lines made of a metal material are disposed only on the plurality of pixel substrates 111 and are not formed to contact the lower substrate 110. I can. Accordingly, various lines may be patterned to correspond to the plurality of pixel substrates 111 and disposed discontinuously.

In the display device 100 according to the first exemplary embodiment of the present invention, in order to connect such discontinuous lines, pads on two adjacent pixel substrates 111 may be connected by a connection line 180. That is, the connection wiring 180 electrically connects the pads on two adjacent pixel substrates 111. Accordingly, the stretchable display device 100 of the present invention has a plurality of connection wirings to electrically connect various lines such as a gate line, a data line, a high potential power line, and a reference voltage line between the plurality of pixel substrates 111. It may include 180. For example, a gate line may be disposed on a plurality of pixel substrates 111 disposed adjacent to each other in the X-axis direction, and gate pads 171 may be disposed at both ends of the gate line. In this case, each of the plurality of gate pads 171 on the plurality of pixel substrates 111 disposed adjacent to each other in the X-axis direction may be connected to each other by a connection wiring 180 functioning as a gate line. Accordingly, the gate line disposed on the plurality of pixel substrates 111 and the connection wiring 180 disposed on the lower substrate 110 may function as one gate line. In addition, all various lines that may be included in the stretchable display device 100, such as a data line, a high potential power line, and a reference voltage line, may also function as one line by the connection wiring 180 as described above. .

Referring to FIG. 6, the first connection wiring 181 may connect pads on two pixel substrates 111 arranged side by side among pads on a plurality of pixel substrates 111 disposed adjacent to each other in the X-axis direction. The first connection wiring 181 may function as a gate line or a low potential power line, but is not limited thereto. For example, the first connection wiring 181 may function as a gate line, and the gate pads 171 on the two pixel substrates 111 arranged side by side in the X-axis direction through a contact hole formed in the bank 116 Can be electrically connected. Thus, as described above, the gate pads 171 on the plurality of pixel substrates 111 arranged in the X-axis direction may be connected by the first connection wiring 181 functioning as a gate line, and one gate signal is Can be delivered.

The second connection wiring 182 may connect pads on two pixel substrates 111 arranged side by side among the pads on the plurality of pixel substrates 111 arranged adjacent to each other in the Y-axis direction. The second connection wiring 182 may function as a data line, a high potential power line, or a reference voltage line, but is not limited thereto. For example, the second connection wiring 182 may function as a data line, and the data pads 173 on two pixel substrates 111 arranged side by side in the Y-axis direction through a contact hole formed in the bank 116 Can be electrically connected. Accordingly, as described above, the data pads 173 on the plurality of pixel substrates 111 arranged in the Y-axis direction may be connected by a plurality of second connection wires 182 functioning as data lines, and one data Signals can be delivered.

Meanwhile, the connection wiring 180 includes a base polymer and conductive particles. Specifically, the first connection wiring 181 includes a base polymer and conductive particles, and the second connection wiring 182 includes a base polymer and conductive particles.

The first connection wiring 181 includes a top surface and a side surface of the bank 116 disposed on the pixel substrate 111, an overcoat layer 115, an interlayer insulating layer 114, a buffer layer 112, and a plurality of pixel substrates 111. ) May be formed to be in contact with the side surface and extend to the upper surface of the lower substrate 110. Accordingly, the first connection wiring 181 is in contact with the upper surface of the lower substrate 110, the buffer layer 112 disposed on the neighboring pixel substrate 111 and in contact with the side surface of the neighboring pixel substrate 111, and gate insulation. The layer 113, the interlayer insulating layer 114, the overcoat layer 115, and the side surfaces of the bank 116 may be in contact. Further, the first connection wiring 181 may contact the connection pad 172 disposed on the neighboring pixel substrate 111, but is not limited thereto.

The base polymer of the first connection wiring 181 may be formed of an insulating material that can be bent or stretched similarly to the lower substrate 110. The base polymer may include, for example, SBS (Styrene Butadiene Styrene), but is not limited thereto. Accordingly, when the stretchable display device 100 is bent or stretched, the base polymer may not be damaged. The base polymer may be formed by coating a material constituting the base polymer on the lower substrate 110 and the pixel substrate 111 or using a slit.

The conductive particles of the first connection wiring 181 may be dispersed in the base polymer. Specifically, the first connection wiring 181 may include conductive particles dispersed at a predetermined concentration in the base polymer. The first connection wiring 181 is, for example, uniformly agitating the conductive particles in the base polymer, and then coating and curing the base polymer in which the conductive particles are dispersed on the lower substrate 110 and the pixel substrate 111. It may be formed in a manner, but is not limited thereto. The conductive particles may include at least one of silver (Ag), gold (Au), and carbon, but is not limited thereto.

Conductive particles dispersed and disposed in the base polymer of the first connection wiring 181 may form a conductive path electrically connecting the connection pads 172 respectively disposed on the pixel substrates 111 adjacent to each other. In addition, a conductive path may be formed by electrically connecting the gate pad 171 formed on the pixel substrate 111 disposed at the outermost of the plurality of pixel substrates 111 and the pad disposed in the non-display area NA.

The base polymer of the first connection wiring 181 and the conductive particles dispersed in the base polymer may connect between the pads disposed on the pixel substrate 111 adjacent to each other in a straight line or curved shape as shown in FIG. 6. To this end, in the manufacturing process, the base polymer may be formed in a straight or curved shape connecting pads disposed on each of the plurality of pixel substrates 111. Accordingly, the conductive path formed by the conductive particles dispersed in the base polymer may also have a straight or curved shape. However, the process and shape of the base polymer and the conductive particles of the first connection wiring 181 may not be limited thereto.

The second connection wiring 182 includes a top surface and a side surface of the bank 116 disposed on the pixel substrate 111, an overcoat layer 115, an interlayer insulating layer 114, a buffer layer 112, and a plurality of pixel substrates 111. ) May be formed to be in contact with the side surface and extend to the upper surface of the lower substrate 110. Accordingly, the second connection wiring 182 is in contact with the upper surface of the lower substrate 110, the buffer layer 112 disposed on the neighboring pixel substrate 111 and in contact with the side surface of the neighboring pixel substrate 111, and gate insulation. The layer 113, the interlayer insulating layer 114, the overcoat layer 115, and the side surfaces of the bank 116 may be in contact. Further, the second connection wiring 182 may contact the data pad 173 disposed on the neighboring pixel substrate 111, but is not limited thereto.

The base polymer of the second connection wiring 182 may be formed of an insulating material that can be bent or stretched similarly to the lower substrate 110, and may be the same material as the base polymer of the first connection wiring 181. The base polymer may include, for example, SBS (Styrene Butadiene Styrene), but is not limited thereto.

In addition, the conductive particles of the second connection wiring 182 may be dispersed in the base polymer. Specifically, the second connection wiring 183 may include conductive particles dispersed at a predetermined concentration in the base polymer. In this case, the concentration of the conductive particles dispersed in the upper portion of the base polymer of the second connection wiring 182 and the concentration of the conductive particles dispersed in the lower portion of the base polymer may be substantially the same. In addition, the manufacturing process of the second connection wiring 181 may be the same as the manufacturing process of the first connection wiring 181 or may be performed at the same time.

Conductive particles dispersed and disposed in the base polymer of the second connection wiring 182 may form a conductive path electrically connecting the data pads 173 respectively disposed on the pixel substrates 111 adjacent to each other. In addition, a conductive path may be formed by electrically connecting the data pad 173 formed on the pixel substrate 111 disposed at the outermost of the plurality of pixel substrates 111 and the pad disposed in the non-display area NA.

The base polymer of the second connection wiring 182 and the conductive particles dispersed in the base polymer may connect between the pads disposed on the pixel substrate 111 adjacent to each other in a linear or curved shape. To this end, in the manufacturing process, the base polymer may be formed in a straight or curved shape connecting pads disposed on each of the plurality of pixel substrates 111. Accordingly, the conductive path formed by the conductive particles dispersed in the base polymer may also have a straight or curved shape. However, the formation process and shape of the base polymer and the conductive particles of the second connection wiring 182 may not be limited thereto.

When the above-described first and second connection wires 181 and 182 have a curved shape, they may have a sine wave shape. However, the shape of the first connection wire 181 and the second connection wire 182 is not limited thereto, and for example, the first connection wire 181 and the second connection wire 182 may extend in a zigzag shape. In addition, a plurality of rhombus-shaped wires may have various shapes, such as being connected to and extending from a vertex.

In some embodiments, the conductive particles dispersed in the base polymer of the connection wiring 180 may have a concentration gradient and may be dispersed and disposed in the base polymer. The concentration of the conductive particles decreases from the top to the bottom of the base polymer, and thus, the conductivity of the conductive particles on the top of the base polymer may be the greatest. Specifically, the conductive particles may be injected and dispersed in the base polymer using an ink printing process or the like using a conductive precursor on the upper surface of the base polymer. In the process of injecting the conductive particles into the base polymer, the polymer may swell several times, and the conductive particles may penetrate into the empty space of the base polymer. Thereafter, when the base polymer injected with the conductive particles is immersed in a reducing material or reduced to a vapor, the connection wiring 180 may be formed. Accordingly, in the penetration region of the upper portion of the base polymer, the concentration of the conductive particles may be high enough to form a conductive path. The thickness of the penetration area dispersed at a high concentration in the conductive particles on the base polymer may vary depending on the time and strength of the conductive particles being injected from the top surface of the base polymer. For example, the conductive particles are injected from the top surface of the base polymer. If the time or strength is increased, the thickness of the penetration area can become thicker. In addition, each of the conductive particles may be in contact with each other on the top of the base polymer, and thus, a conductive path may be formed through the conductive particles in contact with each other to transmit an electrical signal.

In addition, in some embodiments, the base polymer of the connection wiring 180 may be formed as a single layer on the lower substrate 110 between the pixel substrates 111 adjacent to each other. Specifically, the base polymer may be disposed as a single layer while in contact with the lower substrate 110 in a region between the pixel substrates 111 closest to each other in the X-axis direction, unlike that shown in FIG. 6. The base polymer may be formed by overlapping all of the plurality of pads formed in parallel on one side of one pixel substrate 111. In addition, the conductive particles may form a plurality of conductive paths on the base polymer disposed as a single layer and may be separately formed to correspond to each of the plurality of pads. Accordingly, the conductive path formed by the conductive particles may connect the pads disposed on the pixel substrates 111 adjacent to each other in a linear shape, for example, a base disposed as a single layer between the plurality of pixel substrates 111 Conductive particles may be injected to form four conductive paths on the upper surface of the polymer.

In addition, in some embodiments, the base polymer of the connection wiring 180 may be disposed in the entire area except for the area in which the plurality of pixel substrates 111 are disposed. The base polymer may be disposed in a single layer in contact with the lower substrate 110 in the remaining regions of the lower substrate 110 except for a region overlapping with the plurality of rigid substrates, that is, the plurality of pixel substrates 111. Accordingly, the rest of the lower substrate 110 except for a region overlapping with the plurality of pixel substrates 111 may be covered by the base polymer, and the base polymer may be in contact with the pads of the plurality of pixel substrates 111. Some of the polymer may be disposed to cover the edges of the plurality of pixel substrates 111. In addition, the conductive particles may form a conductive path connecting pads on a plurality of pixel substrates 111 adjacent to each other on the base polymer.

When the base polymer is disposed on the lower substrate 110 as a single layer on the entire area except for the area in which the plurality of pixel substrates 111 are disposed, the plurality of pixel substrates 111 among the lower substrate 110 are disposed as the base polymer. Since it may be formed by applying it to all regions except the region, a separate process for patterning the base polymer may not be required. Therefore, the manufacturing process of the base polymer and the connection wiring can be simplified, and the process cost and time can be reduced.

In addition, since the base polymer is disposed in a single layer on the lower substrate 110 in the entire area excluding the area in which the plurality of pixel substrates 111 are disposed, the force applied when the stretchable display device 100 is bent or stretched is reduced. Can be dispersed. Also, in some embodiments, the top surface of the base polymer of the connection wiring 180 may be flat. Specifically, unlike in FIG. 7, the top surface of the base polymer of the connection wiring 180 such as the gate line and the data line may be higher than the top surface of the overcoat layer 115 on the plurality of pixel substrates 111. Also, the upper surface of the base polymer may be higher than the upper surface of the banks 116 on the plurality of pixel substrates 111. Accordingly, the base polymer of the connection wiring 180 may have the same height of an upper surface of a portion overlapping the plurality of pixel substrates 111 and an upper surface of an area disposed between the plurality of pixel substrates 111. Accordingly, the upper surface of the connection wiring 180 may be flat. Accordingly, the upper surface of the conductive particles dispersed on the base polymer may have a straight line shape without curvature on a cross-sectional view.

A step may exist between the upper surface of the bank 116 and the upper surface of the lower substrate 110 due to various components on the plurality of pixel substrates 111 spaced apart from and disposed on the lower substrate 110. In this case, the base polymer itself may be cut off due to a step on the upper surface of the base polymer, so that an electrical path between the pads disposed on the adjacent pixel substrate 111 may be blocked, and the defect rate of the stretchable display device may increase. I can.

In this case, when the top surface of the base polymer is flat, a step difference between the top surfaces of the devices disposed on the plurality of pixel substrates 111 and the top surface of the lower substrate 110 on which the plurality of pixel substrates 111 are not disposed may be eliminated. have. Accordingly, even if the stretchable display device 100 is bent or stretched, a phenomenon in which the connection wiring 180 including the base polymer and the conductive particles is disconnected due to a step difference may be prevented. In addition, in the stretchable display device 100 according to another embodiment of the present invention, since the top surface of the base polymer is flat, damage to the connection wiring 180 during the manufacturing process of the stretchable display device 100 can be minimized. have.

Referring back to FIG. 7, an upper substrate 120, a polarizing layer 190, and an adhesive layer 118 are disposed on the encapsulation layer 117 and the lower substrate 110.

The upper substrate 120 is a substrate supporting various components disposed under the upper substrate 120. The upper substrate 120 is a flexible substrate and may be formed of an insulating material that can be bent or stretched. The upper substrate 120 is a flexible substrate, and may be reversibly expanded and contracted. In addition, the elastic modulus may be several MPa to several hundred MPa, and the elongation failure rate may be 100% or more. The thickness of the upper substrate 120 may be 10 μm to 1 mm, but is not limited thereto.

The upper substrate 120 may be made of the same material as the lower substrate 110, and for example, an elasticity such as a silicone rubber such as polydimethylsiloxane (PDMS) or a polyurethane (polyurethane; PU). It is made of a polymer (elastomer), and thus, may have a flexible property. However, the material of the upper substrate 120 is not limited thereto.

Pressure is applied to the upper substrate 120 and the lower substrate 110 so that the upper substrate 120 and the lower substrate 110 may be bonded to each other by the adhesive layer 118 disposed under the upper substrate 120. However, the present invention is not limited thereto, and the adhesive layer 118 may be omitted according to embodiments.

A polarizing layer 190 is disposed on the upper substrate 120. The polarizing layer 190 may polarize light incident from the outside of the stretchable display device 100. The polarized light that passes through the polarization layer 190 and enters the stretchable display device 100 may be reflected inside the stretchable display device 100, and thus, the phase may be switched. Light whose phase has been switched may not pass through the polarizing layer 190. Accordingly, light incident to the inside of the stretchable display device 100 from the outside of the stretchable display device 100 cannot be emitted again to the outside of the stretchable display device 100. The reflection of external light of) can be reduced.

Meanwhile, since a stretchable display device must have a property of being easily bent or stretched, an attempt has been made to use a substrate having a soft property due to its low modulus. However, when a flexible material such as polydimethylsiloxane (PDMS) having a low modulus is used as a lower substrate disposed while a display device is being manufactured, a transistor or a display device is formed due to the characteristics of the material having a low modulus weak to heat. A problem in that the substrate is damaged by a high temperature generated during the process, for example, a temperature of 100° C. or higher has occurred.

Accordingly, when the display device is formed on a substrate made of a material capable of withstanding high temperatures, damage to the substrate in the process of forming the display device can be prevented. Accordingly, there have been attempts to form a substrate with a material that can withstand high temperatures generated during the manufacturing process, such as polyimide (PI), but materials that can withstand high temperatures have high modulus and do not have ductile properties, so they display stretchable. In the process of stretching the device, there has been a problem that the substrate is difficult to bend or stretch.

Accordingly, in the stretchable display device 100 according to an exemplary embodiment of the present invention, a plurality of pixel substrates 111, which are rigid substrates, are disposed only in a region in which the transistor 150 or the organic light emitting device 160 is disposed. It is possible to prevent damage to the plurality of pixel substrates 111 due to high temperatures in the manufacturing process of the organic light emitting device 160 or 150.

In addition, in the stretchable display device 100 according to an exemplary embodiment, a lower substrate 110 and an upper substrate 120 that are flexible substrates may be disposed below and above the plurality of pixel substrates 111. Accordingly, since the remaining areas of the lower substrate 110 and the upper substrate 120 excluding areas overlapping with the plurality of pixel substrates 111 can be easily stretched or bent, the stretchable display device 100 can be implemented. have. In addition, damage to the transistor 150 and the organic light emitting device 160 disposed on the plurality of pixel substrates 111, which are rigid substrates, may be prevented as the stretchable display device 100 is bent or stretched. .

8 is a schematic cross-sectional view illustrating another example structure of one sub-pixel of the stretchable display device according to the first embodiment of the present invention. The stretchable display device 100 of FIG. 8 is substantially the same as that of the stretchable display device 100 of FIGS. 5 to 7 except that the lower substrate 191 is different, and a redundant description thereof will be omitted. .

Referring to FIG. 8, the lower substrate 191 includes a plurality of first lower patterns 192 and second lower patterns 193. The plurality of first lower patterns 192 are disposed in a region of the lower substrate 191 that overlaps the plurality of pixel substrates 111. The plurality of first lower patterns 192 may be disposed under the plurality of pixel substrates 111 and the upper surface may be adhered to the lower surface of the plurality of pixel substrates 111.

In addition, the second lower pattern 193 is disposed in a region of the lower substrate 192 except for the plurality of first lower patterns 192. The second lower pattern 193 may surround the plurality of first lower patterns 192 and may be disposed on the same plane as the plurality of first lower patterns 192. In addition, the second lower pattern 193 is disposed under the connection wiring 180 and the adhesive layer 118, and the upper surface contacts the lower surface of the connection wiring 180 and the lower surface of the adhesive layer 118.

In this case, the modulus of the plurality of first lower patterns 192 may be greater than that of the second lower pattern 193. Accordingly, the plurality of first lower patterns 192 may be a plurality of rigid lower patterns having rigidity compared to the second lower pattern 193. In addition, the second lower pattern 193 may be a soft lower pattern having ductility compared to the plurality of first lower patterns 192. The modulus of the plurality of first lower patterns 192 may be 1000 times greater than the modulus of the second lower pattern 193, but is not limited thereto.

The plurality of first lower patterns 192 may be made of the same material as the plurality of pixel substrates 111, may be made of a plastic material having flexibility, for example, polyimide (PI). ) It may be made of polyacrylate, polyacetate, or the like. However, the present invention is not limited thereto, and the plurality of first lower patterns 192 may be made of a material having a modulus equal to or smaller than that of the plurality of pixel substrates 111.

In addition, the second lower pattern 193 may be disposed on the same plane as the plurality of first lower patterns 192 and may be disposed surrounding the plurality of first lower patterns 192. The second lower pattern 193 is a soft lower pattern, which may be reversibly expanded and contracted, may have an elastic modulus of several MPa to several hundred MPa, and may have a stretch failure rate of 100% or more. Accordingly, the second lower pattern 193 may be formed of an insulating material that can be bent or stretched, and the second lower pattern 193 is a silicone rubber such as polydimethylsiloxane (PDMS), polyurethane. It is made of an elastomer such as (polyurethane; PU), but is not limited thereto. In this case, the thickness of the second lower pattern 193 may be 10 μm to 1 mm, and the thickness of the first lower pattern 192 may be 1 μm to the thickness of the second lower pattern 193.

In the stretchable display device 100 according to the first embodiment of the present invention, a plurality of first lower patterns 192 and a plurality of first lower patterns in which the lower substrate 191 overlaps the plurality of pixel substrates 111 The second lower pattern 193 except for 192 is included, and the modulus of the plurality of first lower patterns 192 is greater than the modulus of the second lower pattern 193. When the stretchable display device 100 is deformed, such as bent or stretched, the plurality of first lower patterns 192 disposed under the plurality of pixel substrates 111 that are rigid substrates are a plurality of pixel substrates ( 111). Accordingly, various devices disposed on the plurality of pixel substrates 111 may be supported by the plurality of first lower patterns 192 together with the plurality of pixel substrates 111, and the stretchable display device 100 is deformed. The damage can be reduced as it becomes.

In addition, when the stretchable display device 100 is deformed, such as bent or stretched, the plurality of first lower patterns 192 are made of the same material as the plurality of pixel substrates 111, and the modulus of the second lower pattern 193 is By having a higher modulus, the plurality of first lower patterns 192 may not be deformed, such as being stretched more than the plurality of pixel substrates 111, and the plurality of first lower patterns 192 and the plurality of pixel substrates 111 The adhesion between) can be kept firm. Accordingly, in the stretchable display device 100 according to the first embodiment of the present invention, adhesion between the plurality of first lower patterns 192 and the plurality of pixel substrates 111 can be strongly maintained, and The occurrence of defects in the stretchable display device 100 may be reduced even when the chewable display device 100 is continuously deformed, such as bent or stretched.

In addition, the second lower pattern 193 that does not overlap the plurality of pixel substrates 111 has a ductile characteristic compared to the plurality of first lower patterns 192, so that the second lower pattern 193 between the plurality of pixel substrates 111 is The area in which the lower pattern 193 is disposed may be freely bent or stretched. Accordingly, the connection wiring 180 disposed to overlap the second lower pattern 193 may also be bent or stretched more freely. Accordingly, deformation of the stretchable display device 100 according to the first embodiment of the present invention, such as bent or stretched, can be made more easily.

<Second Example>

9 is a cross-sectional view showing a flexible display device according to a second embodiment of the present invention, FIG. 10 is a cross-sectional view showing a light blocking layer according to the present invention, and FIG. 11 is a schematic view of a flexible display device according to a second embodiment of the present invention. It is a cross-sectional view shown as. In the following, the description of the same configuration as in the first embodiment will be briefly described.

Referring to FIG. 9, a flexible display device according to a second embodiment of the present invention includes a lower substrate 200, a light blocking layer 205, a transistor TFT, and an organic light emitting diode (OLED) connected to the transistor TFT. do.

The lower substrate 200 has a groove 201 in one area. The groove 201 is a region in which the light blocking layer 205 is provided, and corresponds to a region requiring a predetermined rigidity so that the transistor TFT and the organic light emitting device OLED can be stacked thereon.

Each of the grooves 201 corresponds to one subpixel. That is, one groove 201 is formed in a one-to-one correspondence as one subpixel. In this embodiment, one groove 201 corresponds to one subpixel on a one-to-one basis, but one groove 201 may be formed to correspond to at least two or more subpixels.

The light blocking layer 205 imparts a predetermined rigidity to the lower substrate 200 and serves to prevent a leakage current from occurring in the active layer 215 of the transistor TFT from light incident from the lower portion. The light blocking layer 205 is not formed on the entire surface of the lower substrate 200, but is formed locally in a predetermined area, since it has a predetermined rigidity and can limit a change in the state of the flexible display device.

Since the light blocking layer 205 described in the second embodiment is the same as the pixel substrate of the first embodiment described above, some overlapping descriptions will be omitted, and a configuration having some differences will be described.

The light blocking layer 205 may be made of a material capable of imparting a predetermined rigidity to the lower substrate 200, blocking light, and imparting a predetermined flexibility. For example, the light blocking layer 205 may be formed of a liquid metal. Since the light blocking layer 205 is made of a liquid metal, the light blocking layer 205 may be filled in the groove 201. The liquid metal may be a metal that is in a liquid state at a use temperature, that is, a process temperature or room temperature. The liquid metal may be made of at least two eutectic alloys selected from the group consisting of Al, Zn, Ga, Ge, Cd, In, Sn, Sb, Hg, Tl, Pb, and Bi. For example, EGaln, Galinstan (Ga/In/Sn), Ga/Sn(92:8), Ga/Al(97:3), Ga/Zn(96:4), Ga/Ag(96 :4) may be, etc.

In addition, the light blocking layer 205 is disposed on the lower substrate 200 to form a transistor (TFT) and/or an organic light-emitting device (OLED) (especially, an organic light-emitting layer). It can function to prevent damage due to exposure to this high temperature environment. In addition, the light blocking layer 205 may function to limit an external force that causes displacement of the transistor (TFT) and/or the organic light emitting device (OLED) when a state change (winding, unwinding, etc.) of the display device is in use. have. That is, the light blocking layer 205 maintains a solid state compared to the surrounding area in the area where the transistor (TFT) and/or the organic light emitting device (OLED) is disposed in the product use environment, It can function as a base layer that can minimize displacement. Accordingly, the light blocking layer 205 may overlap the transistor TFT and the organic light emitting device OLED.

The reason why the light-blocking layer 205 can perform the above-described functions is that when the liquid metal, which is the light-blocking layer 205, is exposed to air, an oxide film is formed on the surface to have a predetermined rigidity.

As shown in FIG. 10, when a liquid metal is formed in the groove 201 and then exposed to air, an oxide film of a certain thickness is formed on the surface of the light blocking layer 205, thereby forming a liquid layer 202 and an oxide layer 204. Is formed. That is, the light blocking layer 205 may have a two-layer structure in which a liquid layer 202 is formed under the liquid layer 202 and an oxide layer 204 is formed on the liquid layer 202. For example, when EGaln is used as a liquid metal, when the EGaln is exposed to air, a gallium oxide layer (GaO) is formed. The gallium oxide layer has sufficient rigidity with a Young's modulus value of 200 GPa, and can serve as a base layer.

The liquid layer 202 is a layer in which a liquid metal is present in a liquid state, and provides a predetermined flexibility to the lower substrate 200. The oxide layer 204 imparts a predetermined rigidity so that the transistor TFT and the organic light emitting diode OLED can be formed on the lower substrate 200.

Accordingly, in the present invention, by forming the light blocking layer 205 of liquid metal, the lower substrate 200 provides flexibility to act as a flexible display device, and a predetermined rigidity is provided to provide a transistor (TFT) and an organic light emitting device on the upper side. (OLED) can be formed.

Meanwhile, the buffer layer 210 is positioned on the lower substrate 200 on which the light blocking layer 205 is formed, and the transistor TFT is positioned on the buffer layer 210. The transistor TFT includes an active layer 215, a gate electrode 235, a source electrode 265 and a drain electrode 270.

Specifically, the active layer 215 is positioned on the buffer layer 210. The active layer 215 may be formed of a silicon semiconductor or an oxide semiconductor. The silicon semiconductor may include amorphous silicon or crystallized polycrystalline silicon. The oxide semiconductor may be Indium Gallium Zinc Oxide (IGZO). The active layer 215 may be doped with impurities to include a source region and a drain region, and a channel region therebetween.

A gate insulating layer 220 and a gate electrode 235 are positioned on the active layer 215 to overlap the channel region of the active layer 215. The gate insulating layer 220 and the gate electrode 235 may be formed through a single mask process or a separate mask process. In the latter case, the gate insulating layer 220 may be widely formed on the entire surface of the lower substrate 200. The gate insulating layer 220 may be silicon oxide (SiOx), silicon nitride (SiNx), or multiple layers thereof.

The gate electrode 235 is selected from the group consisting of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu). It is formed of any one or an alloy thereof. In addition, the gate electrode 235 is a group consisting of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu). It may be a multilayer made of any one selected from or an alloy thereof. For example, the gate electrode 280 may be a double layer of molybdenum/aluminum-neodymium or molybdenum/aluminum. In this embodiment, the gate electrode 235 may have a double-layer structure in which the first lower layer 225 and the first upper layer 230 are stacked.

Meanwhile, a lower capacitor electrode 240 is disposed in a region spaced apart from the gate electrode 235. The gate electrode 235 and the capacitor lower electrode 240 are simultaneously formed by the same mask process. Accordingly, the capacitor lower electrode 240 has the same stacked structure as the gate electrode 235. That is, the capacitor lower electrode 240 may have a double-layer structure in which the first lower layer 225 and the first upper layer 230 are stacked.

In addition, a gate pad 237 is disposed in a region spaced apart from the gate electrode 235 and the capacitor lower electrode 240. The gate pad 237 is simultaneously formed by the same masking process as the gate electrode 235 and the capacitor lower electrode 240 described above. Accordingly, the gate pad 237 has the same lamination structure as the gate electrode 235. That is, the gate pad 237 may have a double-layer structure in which the first lower layer 225 and the first upper layer 230 are stacked.

An interlayer insulating layer 250 is positioned on the gate electrode 235. The interlayer insulating layer 250 insulates the gate electrode 235 and the source/drain electrodes 265 and 270. The interlayer insulating layer 250 may be silicon oxide (SiOx), silicon nitride (SiNx), or multiple layers thereof.

A source electrode 265 and a drain electrode 270 are positioned on the interlayer insulating layer 250. The source electrode 265 and the drain electrode 270 are respectively connected to the source region and the drain region of the active layer 215 through contact holes CH penetrating the interlayer insulating layer 250.

The source electrode 265 and the drain electrode 270 may be formed of a single layer or multiple layers, and when the source electrode 265 and the drain electrode 270 are single layers, molybdenum (Mo), aluminum (Al), chromium ( Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and may be made of any one selected from the group consisting of copper (Cu), or an alloy thereof. In addition, when the source electrode 265 and the drain electrode 270 are multilayers, a double layer of molybdenum/aluminum-neodymium, titanium/aluminum/titanium, molybdenum/aluminum/molybdenum, or a triple layer of molybdenum/aluminum-neodymium/molybdenum is used. Can be done. In the present invention, the source electrode 265 and the drain electrode 270 may have a double layer structure in which the second lower layer 255 and the second upper layer 260 are stacked.

Meanwhile, the capacitor upper electrode 275 is positioned in a region spaced apart from the source electrode 265 and the drain electrode 270. The capacitor upper electrode 275 is formed by the same mask process as the source/drain electrodes 265 and 270. Accordingly, the capacitor upper electrode 275 has the same stack structure as the source/drain electrodes 265 and 270. That is, the capacitor upper electrode 275 may have a double-layer structure in which the second lower layer 255 and the second upper layer 260 are stacked.

A passivation layer 280 is disposed on the transistor TFT to protect the transistor TFT. The passivation layer 280 may be a silicon oxide (SiOx), a silicon nitride (SiNx), or a multilayer thereof.

An overcoat layer 290 is positioned on the passivation layer 280. The overcoat layer 290 may be a planarization layer for flattening a lower step. The overcoat layer 290 is made of organic materials such as photo acryl, polyimide, benzocyclobutene resin, and acrylate, so that the lower step can be flattened. .

An organic light emitting diode (OLED) is positioned on the overcoat layer 290. The organic light-emitting device OLED includes a first electrode 320, a second electrode 350, and an organic emission layer 340 interposed therebetween.

Specifically, the first electrode 320 may be an anode, and is made of a transparent conductive material such as Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), or Zinc Oxide (ZnO). The first electrode 320 is connected to the lower drain electrode 270 through the via hole VIA formed in the overcoat layer 290 and the passivation layer 280. The flexible display device of the present invention may be a top emission type that emits light upward. Accordingly, the first electrode 320 may further include a reflective layer capable of reflecting light, and may have a two-layer structure of ITO/reflective layer or a three-layer structure of ITO/reflective layer/ITO or reflective layer/reflective layer/ITO. In this embodiment, the first reflective layer 300, the second reflective layer 305, and the ITO layer 310 may have a three-layer structure.

The bank 330 is positioned on the overcoat layer 290 on which the first electrode 320 is formed. The bank 330 partitions each subpixel. The bank 330 may be made of an organic material such as polyimide, benzocyclobutene series resin, or acrylate. For example, since the bank 330 is formed over the entire display unit, it is made of the same material as the lower substrate 200 to maintain the flexible characteristics of the display device. The bank 330 is provided with an opening 335 exposing the first electrode 320.

The organic emission layer 340 is positioned in the opening 335 of the bank 330. The organic emission layer 340 includes an emission layer that emits light by combining electrons and holes, and may include a hole injection layer or a hole transport layer between the emission layer and the first electrode 320, and an electron transport layer or an electron injection layer on the emission layer It may include. The emission layer may include an emission layer that emits red (R), green (G), and blue (B) light to implement red (R), green (G), and blue (B). The red (R), green (G), and blue (B) emission layers may be allocated to corresponding subpixels, respectively. In this case, the color filter may be omitted.

The second electrode 350 is positioned on the bank 330 in which the organic emission layer 340 is formed. The second electrode 350 is a cathode electrode and may be made of a material having a low work function. For example, the second electrode 350 may be made of magnesium (Mg), calcium (Ca), aluminum (Al), silver (Ag), or an alloy thereof, and may have a thickness thin enough to transmit light. . In addition, the second electrode 350 may be made of a transparent metal oxide such as IZO. Accordingly, an organic light-emitting device OLED including the first electrode 320, the organic emission layer 340, and the second electrode 350 is configured.

Meanwhile, a connection pad 324 connected to the gate pad 237 is positioned on the overcoat layer 290 in a region spaced apart from the organic light emitting diode (OLED), and a data pad 322 connected to the source electrode 265 in the other region. ) Is located. The connection pad 324 and the data pad 322 are formed by the same mask process as the first electrode 320. Accordingly, the connection pad 324 and the data pad 322 have the same lamination structure as the first electrode 320. That is, the connection pad 324 and the data pad 322 may have a three-layer structure of the first reflective layer 300, the second reflective layer 305, and the ITO layer 310.

A first connection wire 390 connected to the connection pad 324 is located on the bank 330 in a region spaced apart from the organic light emitting diode (OLED), and a second connection wire connected to the data pad 322 ( 392) is located.

The lower substrate 200 on which the organic light-emitting device OLED is formed may be sealed through the encapsulation layer 360. The encapsulation layer 360 may include at least one of a UV resin layer 362, a silicon oxide layer 364, a water repellent coating layer 366, and an anti-fingerprint layer 368. In the present embodiment, a structure including all four layers is illustrated, but the present invention is not limited thereto. An upper substrate 375, a polarizing layer 380, and an adhesive layer 118 are disposed on the encapsulation layer 360 and the lower substrate 200.

As described above, in the flexible display device according to the second embodiment of the present invention, by forming a light blocking layer made of liquid metal in the groove of the lower substrate, flexibility and rigidity are simultaneously provided to the lower substrate, thereby increasing the flexibility of the lower substrate. There is an advantage in that a transistor and an organic light emitting device can be formed on the light blocking layer. Accordingly, even if the flexible display device is bent or bent freely, the adhesive properties and mechanical reliability of the device can be improved.

The above-described flexible display device illustrated in FIG. 9 may be schematically represented as illustrated in FIG. 11.

Referring to FIG. 11, the light blocking layer 205 is positioned in the groove 201 of the lower substrate 200. A transistor TFT and an organic light emitting diode OLED are positioned on the light blocking layer 205 to form subpixels SPX. The above-described buffer layer, interlayer insulating layer, passivation layer, overcoat layer, and bank are not disposed between each subpixel SPX, thereby forming a flexible area FFA in which the flexible display device can be freely bent or bent. The lower substrate 200 on which the organic light emitting element OLED is formed may be sealed by the encapsulation layer 360 to configure the flexible display device of the present invention.

Hereinafter, a method of manufacturing the flexible display device according to the second embodiment of the present invention illustrated in FIG. 11 will be described.

12 to 17 are cross-sectional views showing a method of manufacturing a flexible display device according to a second embodiment of the present invention for each process.

Referring to FIG. 12, a support substrate 400, which is a glass substrate, is prepared, the support substrate 400 is mounted in a chamber, and a sacrificial layer 410 such as amorphous silicon is deposited. Subsequently, as shown in FIG. 13, a lower substrate 420 is formed by coating a transparent and elastic material on the sacrificial layer 410. In this case, a groove 425 is formed in a region of the lower substrate 420 by using a mold or patterning process. Subsequently, a light blocking layer 430 is formed by applying a liquid metal into the groove 425 of the lower substrate 420. The lower substrate 420 on which the light blocking layer 430 is formed is exposed to air to form an oxide layer on the surface of the light blocking layer 430 with a predetermined thickness.

Next, referring to FIGS. 14 and 15, a transistor TFT and an organic light emitting diode OLED are formed on the light blocking layer 430 of the lower substrate 420. Although omitted in the drawing, a buffer layer, a gate insulating layer, an interlayer insulating layer, a passivation layer, an overcoat layer, and a bank interposed between the lower substrate 420, the transistor TFT, and the organic light emitting diode OLED are also formed.

Next, referring to FIG. 16, an encapsulation layer 460 is formed on the lower substrate 420 including the organic light emitting diode (OLED). Although not shown, the encapsulation layer 460 may include at least one of the above-described UV resin layer, silicon oxide layer, water repellent coating layer, and anti-fingerprint layer. The upper substrate 475 on which the polarization layer 480 is formed on the encapsulation layer 460 is adhered to the lower substrate 420 through the adhesive layer 460.

Next, referring to FIG. 17, by irradiating a laser to the sacrificial layer 410 on which the support substrate 400 is formed to separate the support substrate 400 and the lower substrate 420, the second embodiment of the present invention A flexible display device is manufactured according to the following.

Hereinafter, a structure in which the light blocking layer is used as an auxiliary electrode in the third embodiment of the present invention will be described.

18 is a cross-sectional view illustrating a subpixel of a flexible display device according to a third exemplary embodiment of the present invention. Hereinafter, the description of the same configuration as the third embodiment will be briefly described.

<Third Example>

Referring to FIG. 18, a flexible display device according to a third embodiment of the present invention includes a lower substrate 500, a light blocking layer 505, a transistor TFT, and an organic light emitting diode (OLED) connected to the transistor TFT. do.

The lower substrate 500 has a groove 501 in one area. The groove 501 is a region in which the light blocking layer 505 is provided, and corresponds to a region requiring a predetermined rigidity so that the transistor TFT and the organic light emitting device OLED can be stacked thereon. Each of the grooves 501 corresponds to one subpixel.

The light blocking layer 505 imparts a predetermined rigidity to the lower substrate 500 and serves to prevent leakage current from occurring in the active layer 515 of the transistor TFT from light incident from the lower portion. The light blocking layer 505 is not formed on the entire surface of the lower substrate 500 but is formed locally in a predetermined area because it has a predetermined rigidity and can limit a change in the state of the flexible display device.

The light blocking layer 505 may be made of a material capable of imparting a predetermined rigidity to the lower substrate 500, blocking light, and imparting a predetermined flexibility. For example, the light blocking layer 505 may be formed of a liquid metal. The liquid metal may be a metal that is in a liquid state at a use temperature, that is, a process temperature or room temperature. The liquid metal may be made of at least two eutectic alloys selected from the group consisting of Al, Zn, Ga, Ge, Cd, In, Sn, Sb, Hg, Tl, Pb, and Bi. For example, EGaln, Galinstan (Ga/In/Sn), Ga/Sn(92:8), Ga/Al(97:3), Ga/Zn(96:4), Ga/Ag(96 :4) may be, etc.

In addition, the light blocking layer 505 is disposed on the lower substrate 500 so that the lower substrate 500 is formed when a process for forming a transistor (TFT) and/or an organic light emitting device (OLED) (especially, a light emitting layer) is in progress. It can function to prevent damage due to exposure to high temperature environments. In addition, the light blocking layer 505 may function to limit an external force that causes displacement of the transistor (TFT) and/or the organic light emitting device (OLED) when a state change (winding and unwinding, etc.) of the display device is in use. have. That is, the light blocking layer 505 maintains a solid state compared to the surrounding area in the area where the transistor (TFT) and/or the organic light emitting device (OLED) is disposed in the product use environment, It can function as a base layer that can minimize displacement. When the liquid metal constituting the light blocking layer 505 is exposed to air, an oxide film is formed on the surface of the light blocking layer 505 to have a predetermined rigidity, and thus a transistor (TFT) and an organic light emitting device on the light blocking layer 505 (OLED) can be formed.

Accordingly, in the present invention, by forming the light blocking layer 505 of liquid metal, the lower substrate 500 provides flexibility to act as a flexible display device, and a predetermined rigidity is provided to provide a transistor (TFT) and an organic light emitting device on the upper side. (OLED) can be formed.

Meanwhile, the buffer layer 510 is positioned on the lower substrate 500 on which the light blocking layer 505 is formed, and the transistor TFT is positioned on the buffer layer 510. The transistor TFT is disposed to overlap the light blocking layer 505. The transistor TFT includes an active layer 515, a gate electrode 535, a source electrode 565 and a drain electrode 570.

Specifically, the active layer 515 is positioned on the buffer layer 510, and the gate insulating layer 520 and the gate electrode 535 are positioned on the active layer 515 so as to overlap the channel region of the active layer 515. . In the present invention, the gate electrode 535 may have a double-layer structure in which the first lower layer 525 and the first upper layer 530 are stacked. A capacitor lower electrode 540 is disposed in a region spaced apart from the gate electrode 535. The capacitor lower electrode 540 may have a double-layer structure in which the first lower layer 525 and the first upper layer 530 are stacked. In addition, a gate pad 537 is disposed in a region spaced apart from the gate electrode 535 and the capacitor lower electrode 540.

Meanwhile, the first connection pattern 700 is positioned in a region that is spaced apart from the gate electrode 535 and the capacitor lower electrode 540 and overlaps the light blocking layer 505. The first connection pattern 700 is connected to the light blocking layer 505 through the first hole 720 of the buffer layer 510 exposing the light blocking layer 505. The first connection pattern 700 may be formed by the same masking process as the gate electrode 535 and the capacitor lower electrode 540, and may have a structure in which the first lower layer 525 and the first upper layer 530 are stacked.

The interlayer insulating layer 550 is located on the gate electrode 535, the gate pad 537, the capacitor lower electrode 540, and the first connection pattern 700, and the source electrode 565 is on the interlayer insulating layer 550. And a drain electrode 570 is located. The source electrode 565 and the drain electrode 570 are respectively connected to the source region and the drain region of the active layer 515 through contact holes CH penetrating the interlayer insulating layer 550. In the present invention, the source electrode 565 and the drain electrode 570 may have a double layer structure in which the second lower layer 555 and the second upper layer 560 are stacked. A capacitor upper electrode 575 is positioned in a region spaced apart from the source electrode 565 and the drain electrode 570. The capacitor upper electrode 575 may have a double-layer structure in which the second lower layer 555 and the second upper layer 560 are stacked.

Meanwhile, the second connection pattern 710 is positioned in a region that is spaced apart from the source electrode 565, the drain electrode 570, and the capacitor upper electrode 575 and overlaps the light blocking layer 505. The second connection pattern 710 is connected to the first connection pattern 700 through the second hole 730 of the interlayer insulating layer 550 exposing the lower first connection pattern 700. The second connection pattern 710 is formed by the same mask process as the source electrode 565, the drain electrode 570, and the capacitor upper electrode 575, and the second lower layer 555 and the second upper layer 560 are stacked. It can be made of a two-layer structure.

A passivation layer 580 protecting the transistor TFT is disposed on the transistor TFT and the second connection pattern 710, and an overcoat layer 590 is disposed on the passivation layer 580. An organic light emitting diode (OLED) is positioned on the overcoat layer 590. The organic light-emitting device OLED includes a first electrode 620, a second electrode 650, and an organic emission layer 640 interposed therebetween.

Specifically, the first electrode 620 may be an anode, and is connected to the lower source electrode 565 through the via hole VIA formed in the overcoat layer 590 and the passivation layer 580. The flexible display device of the present invention may be a top emission type that emits light upward. Accordingly, the first electrode 620 may further include a reflective layer capable of reflecting light. In this embodiment, the first reflective layer 600, the second reflective layer 605, and the ITO layer 610 may have a three-layer structure.

The bank 630 is positioned on the overcoat layer 590 on which the first electrode 620 is formed. The bank 630 is provided with an opening 635 exposing the first electrode 620. The organic emission layer 640 is located in the opening 635 of the bank 630. The second electrode 650 is positioned on the bank 630 in which the organic emission layer 640 is formed. The second electrode 650 may be a cathode electrode, and in this embodiment, it may be made of IZO. Accordingly, an organic light-emitting device OLED including the first electrode 620, the organic emission layer 640, and the second electrode 650 is formed.

Meanwhile, a connection pad 524 connected to the gate pad 537 is positioned on the overcoat layer 290 in a region spaced apart from the organic light emitting diode (OLED), and a data pad 522 connected to the source electrode 565 in the other region. ) Is located. A first connection wire 590 connected to the connection pad 524 is located on the bank 630 in a region spaced apart from the organic light emitting diode (OLED), and a second connection wire connected to the data pad 522 ( 592) is located.

A third hole 740 exposing the second connection pattern 710 is formed in the passivation layer 590 overlapping the second connection pattern 710, and an overcoat layer 590 overlapping the third hole 740 A fourth hole 750 exposing the third hole 740 is formed in the fourth hole 750, and a fifth hole 760 exposing the fourth hole 750 in the bank 630 overlapping the fourth hole 750 is formed. Is formed. The second electrode 650 of the present invention is connected to the lower second connection pattern 710 through the third hole 740, the fourth hole 750, and the fifth hole 760. Accordingly, the second electrode 650 is connected to the light blocking layer 505 through the second connection pattern 710 and the first connection pattern 700. To this end, the light blocking layer 505, the first connection pattern 700, the second connection pattern 710, and the second electrode 650 are disposed to overlap each other.

The light blocking layer 505 is made of a liquid metal having conductivity, and thus a voltage drop may be prevented by lowering the resistance of the second electrode 650. Accordingly, the light blocking layer 505 acts as an auxiliary electrode for lowering the resistance of the second electrode 650, thereby preventing luminance deviation due to a voltage drop of the second electrode 650 from occurring.

Meanwhile, the lower substrate 500 on which the organic light emitting device OLED is formed may be sealed through the encapsulation layer 660. The encapsulation layer 660 may include at least one of a UV resin layer 662, a silicon oxide layer 664, a water repellent coating layer 666, and an anti-fingerprint layer 668. In the present embodiment, a structure including all four layers is illustrated, but the present invention is not limited thereto. An upper substrate 675, a polarizing layer 680, and an adhesive layer 670 are disposed on the encapsulation layer 660 and the lower substrate 500.

As described above, in the flexible display device according to the third embodiment of the present invention, by forming a light blocking layer made of liquid metal in the groove of the lower substrate, flexibility and rigidity are simultaneously provided to the lower substrate, thereby increasing the flexibility of the lower substrate. There is an advantage in that a transistor and an organic light emitting device can be formed on the light blocking layer. Accordingly, even if the flexible display device is bent or bent freely, the adhesive properties and mechanical reliability of the device can be improved.

In addition, the flexible display device according to the third embodiment of the present invention has an advantage of preventing luminance deviation due to a voltage drop of the second electrode by using a light blocking layer as an auxiliary electrode of the second electrode.

<Fourth Example>

19 is a schematic cross-sectional view of one sub-pixel of a flexible display device according to a fourth exemplary embodiment of the present invention. The flexible display device of FIG. 19 is substantially the same as the flexible display device of FIG. 8 except that the LED 1160 is different from that of the flexible display device of FIG.

Referring to FIG. 19, a common line CL is disposed on the gate insulating layer 113. The common line CL is a line that applies a common voltage to the plurality of sub-pixels SPX. The common line CL may be made of the same material as the source electrode 153 and the drain electrode 154 of the transistor 150, but is not limited thereto.

In addition, a reflective layer 1183 is disposed on the interlayer insulating layer 114. The reflective layer 1183 is a layer for reflecting light emitted toward the lower substrate 410 side of the light emitted from the LED 1160 to the top of the stretchable display 1100 to emit light to the outside. The reflective layer 1183 may be made of a metal material having a high reflectivity.

An adhesive layer 1117 covering the reflective layer 1183 is disposed on the reflective layer 1183. The adhesive layer 1117 is a layer for adhering the LED 1160 on the reflective layer 1183, and may insulate the reflective layer 1183 made of a metallic material and the LED 1160. The adhesive layer 1117 may be formed of a heat curing material or a photo curing material, but is not limited thereto. In FIG. 19, it is illustrated that the adhesive layer 1117 is disposed to cover only the reflective layer 1183, but the position of the adhesive layer 1117 is not limited thereto.

The LED 1160 is disposed on the adhesive layer 1117. The LED 1160 is disposed to overlap the reflective layer 1183. The LED 1160 includes an n-type layer 1161, an active layer 1162, a p-type layer 1163, an n-electrode 1165, and a p-electrode 1164. Hereinafter, it will be described that the LED 1160 having a lateral structure is used as the LED 1160, but the structure of the LED 1160 is not limited thereto.

Specifically, the n-type layer 1161 of the LED 1160 is disposed to overlap the reflective layer 1183 on the adhesive layer 1117. The n-type layer 1161 may be formed by implanting an n-type impurity into gallium nitride having excellent crystallinity. An active layer 1162 is disposed on the n-type layer 1161. The active layer 1162 is a light emitting layer that emits light from the LED 1160 and may be made of a nitride semiconductor, for example, indium gallium nitride. A p-type layer 1163 is disposed on the active layer 1162. The p-type layer 1163 may be formed by implanting p-type impurities into gallium nitride. However, the constituent materials of the n-type layer 1161, the active layer 1162, and the p-type layer 1163 are not limited thereto.

A p-electrode 1164 is disposed on the p-type layer 1163 of the LED 1160. In addition, an n-electrode 1165 is disposed on the n-type layer 1161 of the LED 1160. The n-electrode 1165 is disposed to be spaced apart from the p-electrode 1164. Specifically, in the LED 1160, an n-type layer 1161, an active layer 1162, and a p-type layer 1163 are sequentially stacked, a predetermined portion of the active layer 1162 and the p-type layer 1163 are etched, and the n-electrode It may be manufactured in a manner of forming 1165 and the p-electrode 1164. In this case, a predetermined portion is a space for separating the n-electrode 1165 and the p-electrode 1164, and a predetermined portion may be etched so that a portion of the n-type layer 1161 is exposed. In other words, the surface of the LED 1160 on which the n-electrode 1165 and the p-electrode 1164 are to be disposed may have different height levels rather than a flattened surface. Accordingly, the p-electrode 1164 is disposed on the p-type layer 1163, the n-electrode 1165 is disposed on the n-type layer 1161, and the p-electrode 1164 and the n-electrode 1165 are at different height levels. Are arranged spaced apart from each other. Accordingly, the n-electrode 1165 may be disposed adjacent to the reflective layer 1183 compared to the p-electrode 1164. In addition, the n-electrode 1165 and the p-electrode 1164 may be made of a conductive material, for example, may be made of a transparent conductive oxide. In addition, the n-electrode 1165 and the p-electrode 1164 may be made of the same material, but are not limited thereto.

An overcoat layer 115 is disposed on the interlayer insulating layer 114 and the adhesive layer 118. The overcoat layer 115 is a layer that flattens the upper surface of the transistor 150. The overcoat layer 115 may be disposed while flattening the upper surface of the overcoat layer 115 in a region other than the region in which the LED 1160 is disposed. At this time, the overcoat layer 115 may be composed of two or more layers.

A first electrode 1181 and a second electrode 1182 are disposed on the overcoat layer 115. The first electrode 1181 is an electrode that electrically connects the transistor 150 and the LED 1160. The first electrode 1181 is connected to the p-electrode 1164 of the LED 1160 through a contact hole formed in the planarization layer 115. In addition, the first electrode 1181 is connected to the drain electrode 154 of the transistor 150 through a contact hole formed in the planarization layer 115, the interlayer insulating layer 114, and the adhesive layer 118. However, the present invention is not limited thereto, and the first electrode 1181 may be connected to the source electrode 153 of the transistor 150 depending on the type of the transistor 150. The p electrode 1164 of the LED 1160 and the drain electrode 154 of the transistor 150 are electrically connected by the first electrode 1181.

The second electrode 1182 is an electrode electrically connecting the LED 1160 and the common wiring CL. Specifically, the second electrode 1182 is connected to the common line CL through a contact hole formed in the overcoat layer 115 and the interlayer insulating layer 114, and the LED ( It is connected to the n electrode 1165 of the 1160. Accordingly, the common line CL and the n electrode 1165 of the LED 1160 are electrically connected.

When the stretchable display 1100 is turned on, voltages of different levels may be applied to each of the drain electrode 154 and the common line CL of the transistor 150. A voltage applied to the drain electrode 154 of the transistor 150 may be applied to the first electrode 1181, and a common voltage may be applied to the second electrode 1182. Voltages of different levels may be applied to the p-electrode 1164 and the n-electrode 1165 through the first electrode 1181 and the second electrode 1182, so that the LED 1160 may emit light.

In FIG. 19, it has been described that the transistor 150 is electrically connected to the p-electrode 1164 and the common line CL is electrically connected to the n-electrode 1165, but the present invention is not limited thereto, and the transistor 150 is an n-electrode. It may be electrically connected to the 1165 and the common line CL may be electrically connected to the p-electrode 1164.

The bank 116 is disposed on the overcoat layer 115, the first electrode 1181, the second electrode 1182, the data pad 173, and the connection pad 172. The bank 116 is disposed so as to overlap the end of the reflective layer 1183, and a part of the reflective layer 1183 that does not overlap with the bank 116 may be defined as a light emitting area. The bank 116 may be made of an organic insulating material, and may be made of the same material as the overcoat layer 115. In addition, the bank 116 may be configured to include a black material in order to prevent a color mixture phenomenon from occurring when light emitted from the LED 1160 is transmitted to the adjacent sub-pixel SPX.

The stretchable display device 1100 according to the fourth embodiment of the present invention includes an LED 1160. Since the LED 1160 is made of an inorganic material rather than an organic material, it has excellent reliability and has a longer lifespan than a liquid crystal display device or an organic light emitting device. In addition, the LED 1160 is a device suitable to be applied to very large screens because not only the lighting speed is fast, but also the power consumption is low, the impact resistance is strong, and the stability is excellent. . In particular, since the LED 1160 is made of an inorganic material rather than an organic material, a required encapsulation layer may not be used when an organic light-emitting device is used. Accordingly, in the process of stretching the stretchable display device 1100, an encapsulation layer that may be damaged such as cracks easily generated may be omitted. Therefore, in the stretchable display device 1100 according to the fourth exemplary embodiment of the present invention, the LED 1160 is used as a display element, and the stretchable display device 1100 may be damaged if it is deformed, such as bent or stretched. It is possible to omit the use of the encapsulation layer that is present. In addition, since the LED 1160 is made of an inorganic material, not an organic material, the display element of the stretchable display device 1100 according to the fourth embodiment of the present invention can be protected from moisture or oxygen, and has excellent reliability. can do.

In the stretchable display device 1100 according to the fourth embodiment described above, the use of the LED 1160 as a display element is disclosed, but the present invention is not limited thereto, and a quantum dot QD is further included on the LED 1160. QLED can be implemented.

Through the above description, those skilled in the art will be able to variously change and modify without departing from the spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the content described in the detailed description of the specification, but should be determined by the claims.

200: lower substrate 201: groove
205: light blocking layer 320: first electrode
340: organic emission layer 350: second electrode
360: encapsulation layer TFT: transistor
OLED: organic light emitting device

Claims (15)

A lower substrate including a plurality of grooves;
A light blocking layer formed in the plurality of grooves and made of liquid metal;
A transistor positioned on the light blocking layer; And
A flexible display device including an organic light emitting device positioned on the transistor. The method of claim 1,
The light blocking layer, the transistor, and the organic light emitting diode overlap each other. The method of claim 1,
The light blocking layer includes a liquid layer and an oxide layer disposed on the liquid layer. The method of claim 3,
The liquid layer is made of the liquid metal, and the oxide layer is made of an oxide of the liquid metal. The method of claim 1,
The liquid metal includes at least two eutectic alloys selected from the group consisting of Al, Zn, Ga, Ge, Cd, In, Sn, Sb, Hg, Tl, Pb, and Bi. The method of claim 5,
The eutectic alloys include EGaln, Galinstan (Ga/In/Sn), Ga/Sn (92:8), Ga/Al (97:3), Ga/Zn (96:4) and Ga/Ag (96 : A flexible display device comprising at least one selected from the group consisting of 4). The method of claim 1,
The light blocking layer is filled in the groove. The method of claim 1,
Each of the plurality of grooves corresponds to one subpixel on a one-to-one basis. The method of claim 1,
The transistor,
An active layer on the light blocking layer;
A gate insulating layer on the active layer;
A gate electrode on the gate insulating layer;
An interlayer insulating layer on the gate electrode; And
A flexible display device including a source electrode and a drain electrode on the interlayer insulating layer. The method of claim 1,
The organic light emitting device,
A first electrode connected to the transistor;
An organic emission layer on the first electrode; And
A flexible display device including a second electrode on the organic emission layer. The method of claim 10,
The second electrode is connected to the light blocking layer. The method of claim 11,
The second electrode is connected to the light blocking layer through a first connection pattern and a second connection pattern positioned on the light blocking layer. The method of claim 12,
The light blocking layer, the first connection pattern, the second connection pattern, and the second electrode overlap each other. The method of claim 13,
The first connection pattern is located between the light blocking layer and the second connection pattern, and the second connection pattern is located between the first connection pattern and the second electrode. The method of claim 1,
The flexible display device further comprising an encapsulation layer disposed on the organic light emitting device and including at least one of a UV resin layer, a silicon oxide layer, a water repellent coating layer, and a fingerprint protection layer.

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