KR20210086318A - Flexible display apparatus and electronic device comprising the same - Google Patents

Abstract

A flexible display apparatus according to various examples of the present specification includes: a flexible substrate including a first area, a second area, and a bending area; and a protective layer covering the bending area of the flexible substrate. The protective layer may extend to at least a portion of the first area past a boundary between the first area and the bending area. Therefore, provided is an effect of preventing or minimizing damage such as cracks or the like to the bending area.

Description

Flexible display device and electronic device including same {FLEXIBLE DISPLAY APPARATUS AND ELECTRONIC DEVICE COMPRISING THE SAME}

The present specification relates to a flexible display device and an electronic device including the same.

As a liquid crystal display device, an organic light emitting display device, or an electrophoretic display device among display devices can be reduced in thickness, research and development for implementing at least a portion of the flexible display device as a flexible display device is in progress. The flexible display device is formed by forming a display unit including a thin film transistor and wiring on a flexible flexible substrate, and since it is possible to display an image even if it is bent like paper, it can be used in various display fields.

In such a flexible display device, when the periphery of the display area is bent, the driving element or the like is positioned on the opposite surface of the display area, so that the size of the bezel of the display device can be reduced.

However, when the periphery of the display area is bent, there is a problem in that a plurality of wirings formed in the bending area may be damaged such as cracks.

The content of the background art described above is technical information that the inventor of the present specification possessed to derive the example of the present specification or acquired in the process of deriving the example of the present specification, and must be provided to the general public prior to the filing of the present specification. It cannot be said that it is publicly known technology.

An object of the present specification is to provide a flexible display device including a protective layer capable of uniformly protecting a bending area of the flexible display device with a thin film, and an electronic device including the same.

In addition to the tasks of the present specification mentioned above, other features and advantages of the present specification may be described below or clearly understood by those of ordinary skill in the art to which the technical spirit of the present specification belongs from such descriptions and descriptions. will be.

A flexible display device according to various examples of the present specification includes a flexible substrate including a first region, a second region, and a bending region, and a protective layer covering the bending region of the flexible substrate, wherein the protective layer includes the It may extend to at least a portion of the first area past a boundary between the first area and the bending area.

An electronic device according to various examples of the present specification includes a cover window, an image display device coupled to the cover window, and a housing supporting the cover window and accommodating the image display device, wherein the image display device includes a first A flexible substrate including a region, a second region, and a bending region, and a protective layer covering the bending region of the flexible substrate, wherein the protective layer passes through a boundary between the first region and the bending region, and the first region A flexible display device extending to at least a part of the area may be included.

The flexible display device and the electronic device including the same according to the present specification include a protective layer capable of uniformly protecting the bending region of the flexible display device with a thin film, thereby preventing or minimizing damage such as cracks in the bending region. .

In addition to the effects of the present specification mentioned above, other features and advantages of the present specification will be described below or will be clearly understood by those skilled in the art from such description and description.

1 illustrates an exemplary flexible display device that may be included in an electronic device of the present specification.
2 is a cross-sectional view illustrating a bending structure of a flexible display device according to an example of the present specification.
3 is a cross-sectional view illustrating a stacked structure of a flexible display device according to another example of the present specification.
4 is a plan view illustrating a configuration of a flexible display device before bending according to an example of the present specification.
5A to 5C are cross-sectional views illustrating a configuration of a flexible display device before bending according to various examples of the present specification.
6A to 6C are views illustrating a shape of a protective layer used in a flexible display device according to various examples of the present specification.
7 to 11 are views illustrating a manufacturing process of a flexible display device according to an example of the present specification.

Advantages and features of the present specification, and a method of achieving them will become apparent with reference to examples described below in detail in conjunction with the accompanying drawings. However, the present specification is not limited to the examples disclosed below, but will be implemented in various different forms, and only examples of the present specification allow the disclosure of the present specification to be complete, and in the technical field to which the technical spirit of the present specification belongs It is provided to fully inform those of ordinary skill in the scope of the technical idea of the present specification, and examples of the present specification are only defined by the scope of the claims.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining an example of the present specification are exemplary and are not limited to the matters illustrated in the drawings of the present specification. Like reference numerals refer to like elements throughout. In addition, in describing an example of the present specification, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present specification, the detailed description thereof will be omitted.

When 'including', 'having', 'consisting', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the case in which the plural is included is included unless otherwise explicitly stated.

In interpreting the components, it is interpreted as including an error range even if there is no separate explicit description.

In the case of a description of the positional relationship, for example, when the positional relationship of two parts is described as 'on', 'on', 'on', 'beside', etc., 'right' Alternatively, one or more other parts may be positioned between the two parts unless 'directly' is used.

In the case of a description of a temporal relationship, for example, 'immediately' or 'directly' when a temporal relationship is described with 'after', 'following', 'after', 'before', etc. It may include cases that are not continuous unless this is used.

Although the first, second, etc. are used to describe various elements, these elements are not limited by these terms. These terms are only used to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the spirit of the present specification.

"First horizontal axis direction", "second horizontal axis direction" and "vertical axis direction" should not be construed only as a geometric relationship in which the relationship between each other is vertical, and the range in which the configuration of the present specification can function functionally It may mean to have a broader direction than within.

The term “at least one” should be understood to include all possible combinations from one or more related items. For example, the meaning of "at least one of the first, second, and third items" means 2 of the first, second, and third items as well as each of the first, second, or third items. It may mean a combination of all items that can be presented from more than one.

Each feature of the various examples of the present specification may be partially or wholly combined or combined with each other, technically various interlocking and driving are possible, and each example may be implemented independently of each other or may be implemented together in a related relationship. .

Hereinafter, a preferred example of a flexible display device and an electronic device including the same according to the present specification will be described in detail with reference to the accompanying drawings. In adding reference numerals to components of each drawing, the same components may have the same reference numerals as much as possible even though they are indicated in different drawings. And, since the scales of the components shown in the accompanying drawings have different scales from the actual for convenience of explanation, the scales shown in the drawings are not limited thereto.

1 is a diagram illustrating an exemplary flexible display device that may be included in an electronic device of the present specification.

A flexible display device refers to a display device to which flexibility is imparted, and includes a bendable display device, a rollable display device, an unbreakable display device, and a foldable display device. It may be used in a similar meaning to a foldable display device.

The flexible display apparatus 100 includes at least one active area (A/A), and a display unit formed as an array of pixels is formed in the display area. One or more inactive areas (I/A) may be disposed around the display area. For example, the non-display area may be adjacent to one or more sides of the display area.

The non-display area surrounds the rectangular display area. However, the shape of the display area and the shape/arrangement of the non-display area adjacent to the display area are not limited to the example illustrated in FIG. 1 .

The display area and the non-display area may have a shape suitable for designing an electronic device on which the flexible display apparatus 100 is mounted. An exemplary shape of the display area may be a rectangle, a pentagon, a hexagon, a circle, an oval, and the like, but is not limited thereto.

Each pixel of the display unit in the display area may be associated with a pixel circuit. The pixel circuit may include one or more switching transistors and one or more driving transistors on a backplane. Each pixel circuit may be electrically connected to a gate line and a data line to communicate with one or more driving circuits such as a gate driver and a data driver located in the non-display area.

The driving circuit 112 may be implemented as a thin film transistor (TFT) in the non-display area. Such a driving circuit 112 may be referred to as a gate-in-panel (GIP). In addition, some components, such as a data driver integrated circuit (IC), may be mounted on a printed circuit board. Combining with connection interfaces, for example, pads, bumps, pins, etc., arranged in the non-display area using circuit films such as flexible printed circuit board (FPCB), chip on film (COF), and tape-carrier-package (TCP) can be

The flexible display apparatus 100 may include various additional elements for generating various signals or driving the display unit in the display area. Additional elements for driving each pixel of the display unit may include an inverter circuit, a multiplexer, an electrostatic discharge (ESD) circuit, and the like. The flexible display apparatus 100 may include additional elements that provide a touch sensing function, a user authentication function (eg, fingerprint recognition), a multi-level pressure sensing function, a tactile feedback function, and the like. The above-mentioned additional elements may be located in the non-display area and/or in an external circuit connected to the connection interface.

The flexible substrate 110 may be made of a material having flexibility to enable bending. For example, the flexible substrate 110 may be implemented as a thin plastic film made of a polymer such as polyimide (PI), polyethylene naphtahlate (PEN), polyethylene terephalate (PET), and the like. , but is not limited thereto. Accordingly, the flexible substrate 110 may be bent. For example, the flexible substrate 110 may be bent in a horizontal direction, a vertical direction, or a diagonal direction. Accordingly, the flexible substrate 110 may be bent in a combination of vertical, horizontal, and diagonal directions based on a design required for the flexible display apparatus 100 , and the bending direction is not limited thereto.

The flexible substrate 110 may include a first region, a bending region extending from one side of the first region, and a second region extending from one side of the bending region. The first area may be defined as a non-bending area (N/A) including an active area (A/A), and the second area is opposite to the first area with respect to the bending area. It may be defined as a non-bending area including a positioned inactive area (I/A).

A portion of the flexible substrate 110 may be bent, for example, as illustrated in FIG. 1 , a lower end of the display area may be bent. For example, the flexible substrate 110 may be bent in the bending area B/A so that the second area may be folded behind the first area.

Also, in FIG. 1 , the non-display area of the flexible substrate 110 is bent, and a portion of the display area of the flexible substrate 110 may be bent. In this case, an image may be displayed in the bent area of the display area, and the flexible display apparatus 100 may include a substantially flat display area and a curved display area.

The pad part 114 may be disposed in the non-display area of the second area of the flexible substrate 110 . For example, as shown in FIG. 1 , the pad part 114 may be disposed in a non-display area in contact with the bending area at the lower end of the flexible substrate 110 . The pad part 114 is connected to a circuit film such as an FPCB, and may be a contact terminal connecting the circuit film and the plurality of wiring lines 118 to each other.

A thin film transistor connected to the organic light emitting diode may be disposed in the display area. The thin film transistor operates in association with the driving circuit 112 located in the non-display area, and may control the amount of driving current provided to the organic light emitting diode.

The driving circuit 112 is disposed in the non-display area of the flexible substrate 110 and may provide a driving signal to the thin film transistor. For example, the driving circuit 112 may be a gate driver providing a gate signal to the thin film transistor. The driving circuit 112 includes various gate driving circuits, and the gate driving circuits may be directly formed on the flexible substrate 110 . In this case, the driving circuit 112 may be referred to as a gate-in-panel (GIP).

The display driving circuit unit providing the data signal to the thin film transistor is connected to the flexible substrate 110 through a flexible circuit film such as a flexible printed circuit board (FPCB), or the flexible substrate 110 in the same manner as the COF. ) may be directly disposed on the pad portion 114 of the .

2 is a cross-sectional view illustrating a bending structure of a flexible display device according to an example of the present specification.

The flexible substrate 110 may include a first area, a bending area B/A extending from one side of the first area, and a second area extending from one side of the bending area. The first area may be defined as a non-bending area N/A including the display area A/A, and the second area may be a non-display area I positioned opposite to the first area with respect to the bending area. It may be defined as a non-bending area (N/A) including /A).

As shown in FIG. 2 , a first back plate 130A is attached to the display area 101 of the flexible substrate 110 , and a second support plate 130B is attached to the non-display area 103 . can be glued. A support member 140 may be additionally formed between the first support plate 130A attached to the display area 101 of the flexible substrate 110 and the second support plate 130B attached to the non-display area 103 . can A polarization layer 160 may be formed on the display area 101 of the flexible substrate 110 , and a cover window 180 may be formed on the polarization layer 160 . In addition, a pad part 114 may be included on the non-display area 103 of the flexible substrate 110 , and the flexible circuit film 190 may be attached to the pad part 114 .

In FIG. 2 , the support member 140 may be a mandrel or a foam tape.

According to various examples of the present specification, the protective layer 120 may be formed on the flexible substrate 110 . If there are no multiple layers in the bending region of the flexible substrate 110 , a protective layer may be required for wirings, for example, wiring structures in the bending region. In addition, since the inorganic insulating layers may be etched in the bending region of the flexible substrate 110 , wires in the bending region may be vulnerable to moisture and other foreign substances.

In particular, in the manufacturing process of the flexible display apparatus 100 , various pads and wirings for testing components may be chamfered, which may leave wiring extending to the recessed corner of the flexible substrate 110 . These wirings can be easily corroded by moisture, and the corrosion can extend to other wirings in the vicinity of the wiring.

In addition, when the flexible substrate 110 is bent, tensile pressure is applied to the outer surface of the flexible substrate 110 and compression pressure is applied to the inner surface of the flexible substrate 110 . Accordingly, a plurality of wiring lines configured in the bending region 102 of the flexible substrate 110 may be subjected to a tensile pressure, and thus a problem of disconnection of the wiring may occur. This is because the wiring is more susceptible to tensile pressure than compressive pressure.

Accordingly, a protective layer 120 , which may also be referred to as a “micro-coating-layer”, may be disposed over the conductor and/or interconnect structure of the bending region.

The protective layer 120 may be coated on the bending region with a material having a specific modulus to a specific thickness to adjust a neutral plane of the flexible substrate 110 in the bending region. Herein, the neutral surface is a surface on which neither the tensile pressure nor the compressive pressure acts as the flexible substrate 110 is bent while the inner surface is subjected to compression pressure and the outer surface is subjected to tensile pressure. That is, by adding the protective layer 120 to the flexible substrate 110 to move the position of the neutral plane that does not receive the tensile pressure of the outer surface and the compressive pressure of the inner surface of the flexible substrate 110 , the position of the neutral surface is flexible. The substrate 110 may be positioned on a surface where the wiring line is configured. Accordingly, the wiring lines on the flexible substrate 110 are positioned on the neutral plane between the flexible substrate 110 and the protective layer 120 so that when the bending area of the flexible substrate 110 is bent in a curved shape, the Since it is subjected to bending stress, it can be bent without being damaged by the bending stress.

The protective layer 120 may be disposed to cover the bending area 102 of the flexible substrate 110 and extend to at least a portion of the display area 101 of the flexible substrate 110 . As shown in FIG. 2 , a polarization layer 160 may be attached to one surface of the display area 101 of the flexible substrate 110 on the flexible substrate 110 by an adhesive member 160A. One end of the protective layer 120 may be disposed to partially overlap the polarization layer 160 . To this end, the adhesive member 160A may be made of a soft material and may be formed to be thicker than the thickness of the protective layer 120 . The adhesive member 160A may be applied to cover one end of the protective layer 120 in a form in which a step difference between the protective layer 120 and the polarizing layer 160 is filled. As described above, by partially overlapping the polarizing layer 160 on the protective layer 120 , it is possible to prevent the protective layer 120 from being peeled from the flexible substrate 110 , and thus the protective layer 120 and the polarizing layer ( 160) can be prevented.

The protective layer 120 may be disposed to cover the bending region 102 of the flexible substrate 110 and extend to at least a portion of the non-display region 103 of the flexible substrate 110 . As shown in FIG. 2 , one surface of the non-display area 103 of the flexible substrate 110 may include a pad part 114 to which the flexible circuit film 190 is attached, and is formed on the pad part 114 . The flexible circuit film 190 may be attached by the conductive adhesive member 160B. The other end of the protective layer 120 may be disposed to be spaced apart from the pad part 114 by a predetermined distance. That is, the protective layer 120 is disposed so as not to overlap the pad part 114 , so that the flexible circuit film 190 is not prevented from being attached to the pad part 114 . In addition, the conductive adhesive member 160B may include a conductive material, and may be applied to cover at least a portion of the protective layer 120 to a thickness smaller than the thickness of the protective layer 120 . As described above, a portion of the protective layer 120 spaced apart from the pad part 114 of the flexible substrate 110 by a conductive adhesive member 160B is covered by the protective layer 120 and the flexible circuit film 190 . It is possible to prevent moisture permeation through.

The protective layer 120 according to various examples of the present specification may have sufficient flexibility to be used in a bending region of the flexible substrate 110 . In addition, the protective layer 120 may be formed of a material having a specific modulus in order to protect the wiring in the bending region with a uniform and thin thickness. The protective layer 120 may be a material having a modulus of 0.2 GPa or more, preferably a material having a modulus of 9 GPa. In addition, the protective layer 120 may be made of polyimide (PI) having a high modulus of 0.2 GPa or more, and preferably, polyimide having a modulus of 9 GPa.

The flexible display device according to various examples of the present specification uses polyimide having a high modulus of 0.2 GPa or more as the protective layer 120 on the flexible substrate 110, so that the position of the neutral plane is moved to the region where the wiring is configured. It is effective in preventing disconnection of When a high modulus polyimide and a conventional low modulus resin are formed in the same thickness on a flexible substrate with wiring, the conventional low modulus resin has a neutral plane located at a lower level than the position where the wiring is configured, so that the wiring of the flexible substrate is difficult. Since it is subjected to tensile pressure, the possibility of disconnection of the wiring is high. However, in the high modulus polyimide, since the neutral plane is located above the position of the wiring, the wiring of the flexible substrate is subjected to compressive pressure, so that the possibility of disconnection of the wiring is low. As described above, by using polyimide having a high modulus of 0.2 GPa or more as the protective layer 120 , the thickness of the protective layer can be made thinner than that of the existing low modulus resin, thereby configuring a thin flexor display device. It can be advantageous to

3 is a cross-sectional view illustrating a stacked structure of a flexible display device according to another example of the present specification.

The flexible substrate 110 may include a first area, a bending area B/A extending from one side of the first area, and a second area extending from one side of the bending area. The first area may be defined as a non-bending area N/A including the display area A/A, and the second area may be a non-display area I positioned opposite to the first area with respect to the bending area. It may be defined as a non-bending area (N/A) including /A).

In order to increase strength and/or rigidity in a specific portion of the flexible display apparatus 100 , one or more support plates 130A and 130B may be provided on the lower side of the flexible substrate 110 , for example, on the rear surface. The first support plate 130A may be provided on one surface of the display area 101 , and the second support plate 130B may be provided on one surface of the non-display area 103 . The support plates 130A and 130B may not be provided in the bending area 102 requiring greater flexibility. When the flexible substrate 110 has greater elasticity than the support plates 130A and 130B, the support plates 130A and 130B may suppress the occurrence of cracks or other damage in the flexible substrate 110 .

3 , a first support plate 130A may be attached to the display area 101 of the flexible substrate 110 , and a second support plate 130B may be attached to the non-display area 103 . . A support member 140 is additionally formed between the first support plate 130A attached to the display area 101 of the flexible substrate 110 and the second support plate 130B attached to the non-display area 103 , , a portion of the support member 140 may extend to the bending region 102 and be adhered thereto.

An organic light emitting display device (OLED) layer 154 is formed on the display area 101 of the flexible substrate 110 , and an encapsulation layer 150 is formed on the organic light emitting device layer 154 , and encapsulation is performed. A polarization layer 160 may be formed on the layer 150 , and a cover window 180 may be formed on the polarization layer 160 . In addition, a pad part 114 may be included on the non-display area 103 of the flexible substrate 110 , and the flexible circuit film 190 may be attached to the pad part 114 .

Here, the support plate includes a first support plate 130A and a second support plate 130B. The first support plate 130A may be adhered to one surface of the display area 101 of the flexible substrate 110 to support the flexible substrate 110 , and the second support plate 130B is the flexible substrate 110 . The flexible substrate 110 may be supported by being adhered to one surface of the non-display area 103 .

The support member 140 may include a body portion 140A and a rounded end portion 140B extending from the body portion 140A. One surface of the body portion 140A of the support member 140 is attached to the first support plate 130A attached to the display area 101 of the flexible substrate 110 , and the other surface is attached to the non-display area 103 . It may be adhered to the adhered second support plate 130B. In addition, the round end portion 140B of the support member 140 extends from the body portion 140A to support the flexible substrate 110 to be bent while in contact with the bending region 102 of the flexible substrate 110 . .

Accordingly, by additionally configuring the support member 140 , the first support plate 130A of the display area 101 and the second support plate 130B of the non-display area 103 are supported, and the bending area 102 . can support In addition, it is possible to minimize damage or deformation of the flexible substrate 110 due to an external impact or the like. In addition, it is possible to minimize cracks in the flexible substrate 110 or disconnection of wires formed in the bending region 102 . In addition, the flexible substrate 110 may be supported and the bending shape may be maintained.

Here, the support member 140 may be alternatively used in the form of a mandrel or a foam tape.

The bending area 102 may be bent outwardly from the display area 101 at a bending angle and a bending radius with respect to the bending axis.

During the manufacturing process, some portions of the flexible display apparatus 100 may be exposed to external light. A material used for manufacturing the components or the components themselves may be exposed to light during manufacturing of the flexible display device 100 . This results in undesirable state changes, such as threshold voltage transitions in the TFT. Some portions of the flexible display apparatus 100 may be excessively exposed to external light compared to other portions. And this may cause display non-uniformity (eg mura, shadow defects, etc.). In order to minimize this problem, the flexible substrate 110 and/or the support plate may include one or more materials capable of reducing the influence of external light.

A TFT using a low temperature poly silicon (LTPS) semiconductor layer as an active layer is also implemented on the flexible substrate 110 of the flexible display apparatus 100 . In one example, the pixel circuit and the driving circuit (eg, GIP) on the flexible substrate 110 may include one or more CMOS circuits in order to reduce the number of wires for controlling the scan signal on the gate line.

And in some examples, the flexible display apparatus 100 may employ various types of TFTs to implement driving circuits in the non-display area and/or the pixel circuit in the display area. For example, on the flexible substrate 110 of the flexible display apparatus 100 , it may be used as a combination of an oxide semiconductor TFT and an LTPS TFT. The LTPS TFT generally exhibits excellent carrier mobility even in a small profile, and thus may be suitable for implementing an integrated driving circuit. Excellent carrier mobility can be effective in applying LTPS TFTs to components requiring high operating speed. In addition, an initial threshold voltage may be different between the LTPS TFTs due to a grain boundary of the polysilicon semiconductor layer.

An oxide TFT is a TFT employing an oxide-based semiconductor layer such as an indium-gallium-znc-oxide (IGZO) semiconductor layer (hereinafter referred to as an “oxide TFT”), and is different from an LTPS TFT. For example, in spite of low mobility compared to LTPS TFTs, oxide TFTs are generally more advantageous than LTPS TFTs in power efficiency. The low leakage current of the oxide TFT in the off state makes the active state last longer. This can be an important advantage for driving a pixel at a reduced frame rate when a high frame rate is not required to drive the pixel.

In FIG. 3 , the organic light emitting device layer 154 may be disposed on the flexible substrate 110 . The organic light emitting device layer 154 may include a plurality of organic light emitting devices. The organic light emitting diode may be controlled by a pixel circuit and a driving circuit implemented on the flexible substrate 110 , and another external driving circuit connected to a connection interface on the flexible substrate 110 . The organic light emitting device layer 154 may include an organic light emitting material layer emitting light of a specific color (eg, red, green, or blue). In some examples, the organic light emitting material layer may have a layered structure capable of emitting white light, for example, a combination of multiple colors of light.

The encapsulation layer 150 is provided to protect the organic light emitting device layer 154 from external air and moisture. The encapsulation layer 150 may include several material layers to reduce the penetration of air and moisture. In some examples, the encapsulation layer 150 may be provided in a thin film shape, for example, a barrier film.

The flexible display apparatus 100 may include a polarization layer 160 to control a display area (eg, external light reflection, color accuracy, luminance, etc.). In addition, the cover window 180 on the polarization layer 160 may be used to protect the flexible display apparatus 100 .

An electrode for sensing a user's touch input may be formed on one surface of the cover window 180 and/or at least one surface of the polarization layer 160 . If necessary, an independent layer (hereinafter, referred to as a touch sensor layer 170 ) including touch sensing electrodes and/or other components related to sensing a touch input may be provided in the flexible display device 100 .

The touch sensor layer 170 may include one or more deformable dielectric materials. One or more electrodes may interface with the touch sensor layer 170 or may be located in the vicinity of the touch sensor layer 170, and may read a signal for measuring an electrical change on the electrode. This measurement is analyzed and the amount of pressure input to the flexible display apparatus 100 is evaluated at various levels.

In some examples, the touch sensitive electrode may be utilized to locate the user input and evaluate the pressure of the user input. The touch input position confirmation and touch pressure measurement may be performed by measuring a change in capacitance of a touch sensing electrode on one surface of the touch sensor layer 170 . The touch sensing electrode and/or other electrode may be used to measure a signal indicating a pressure on the flexible display apparatus 100 by a touch input. This signal is obtained from the touch sensing electrode at the same time as the touch signal or at a different timing.

The deformable material included in the touch sensor layer 170 may be an electrically active material, and the amplitude and/or frequency of the material is controlled by an electric signal and/or an electric field. Such modifying materials include piezo ceramics, electro-active-polymers, and the like. Accordingly, the touch sensing electrode and/or the separate electrode may activate the deformable material to bend the flexible display apparatus 100 in a desired direction. Additionally, the electrically active material is activated and vibrates at a desired frequency to provide tactile and/or texture feedback on the flexible display device 100 . The flexible display apparatus 100 may employ a plurality of electrically active materials to provide bending or vibration of the flexible display apparatus 100 at the same time or at different timings.

Various other components, for example, the polarization layer 160 and the touch sensor layer 170 may not exist in the bending region.

3 , a protective layer 120 may be formed on the flexible substrate 110 . The protective layer 120 may be disposed to cover the bending area 102 of the flexible substrate 110 and extend to at least a portion of the display area 101 and/or the non-display area 103 .

The protective layer 120 may be disposed to be spaced apart from the encapsulation layer 150 on the display area 101 of the flexible substrate 110 by a predetermined distance. The thickness of the protective layer 220 may be 18 μm or more. For example, the thickness of the protective layer 120 may be substantially the same as the thickness of the encapsulation layer 150 (from the flexible substrate 110 to the top surface of the encapsulation layer 150 ). In addition, the polarization layer 160 may be attached to overlap a portion of the protective layer 120 on the encapsulation layer 150 and the protective layer 120 of the flexible substrate 110 . At this time, the adhesive member 160A is formed between the polarization layer 160 and the encapsulation layer 150 , and the adhesive member 160A is protected in a form in which the step difference between the protective layer 120 and the polarization layer 160 is filled. It may be applied to cover one end of the layer 120 . To this end, the adhesive member 160A may be made of a soft material and may be formed to be thicker than the thickness of the protective layer 120 . As such, when the protective layer 120 is spaced apart from the encapsulation layer 150 by a predetermined distance, its upper surface is covered by the polarizing layer 160 and the adhesive member 160A, so that the protective layer 120 is formed on the flexible substrate ( 110 ), so that moisture permeation between the protective layer 120 and the polarizing layer 160 and/or between the protective layer 120 and the encapsulation layer 150 can be prevented.

The protective layer 120 may be disposed to be spaced apart from the pad part 114 on the non-display area 102 of the flexible substrate 110 by a predetermined distance. In addition, the flexible circuit film 190 may be attached on the pad part 114 of the flexible substrate 110 . In this case, a conductive adhesive member 190A is formed between the flexible circuit film 190 and the pad part 114 , and the conductive adhesive member 190A may be applied to cover at least a portion of the protective layer 120 . To this end, the conductive adhesive member 190A may include a conductive material and be thinner than the thickness of the protective layer 120 . In this way, when the protective layer 120 is spaced apart from the pad part 114 by a predetermined distance, the upper surface thereof is covered by the conductive adhesive member 190A, thereby providing a gap between the protective layer 120 and the flexible circuit film 190 . It can prevent moisture permeation.

4 is a plan view illustrating the configuration of the flexible display device before bending according to an example of the present specification, and FIGS. 5A to 5C are cross-sectional views illustrating the configuration of the flexible display device before bending according to various examples of the present specification.

4 and 5A to 5C, the flexible substrate 110 has a display area 101 in which the display unit A/A is positioned, and a pad unit 114 to which the flexible circuit film 190 is attached. It includes a non-display area 103 in which is located and a bending area 102 in which a plurality of wires (not shown) for connecting electrical signals from the display unit A/A to the pad unit 114 are formed. In one example of the present specification, the protective layer 120 is disposed to cover the bending area 102 , and extends toward the display area 101 and the non-display area 103 to the display area 101 and/or the non-display area. At least a portion of the region 103 may be covered. In one example, one end of the protective layer 120 is formed to be spaced apart from the display unit A/A of the flexible substrate 110 by a predetermined distance, and the other end of the protective layer 120 is a pad portion ( 114) may be formed to be spaced apart from each other by a predetermined distance. In this case, the open space between the protective layer 120 and the display unit A/A or the pad unit 114 may be a defect area through which moisture may penetrate.

Accordingly, in some examples, the protective layer 120 is a polarizing layer ( ) on the protective layer 120 extending toward the display area 101 of the flexible substrate 110 as shown in FIGS. 4 and 5A to 5C . 160) may be partially overlapped. In addition, as shown in FIGS. 4 and 5A and 5B , the protective layer 120 may be used for attaching the flexible circuit film 190 to the pad part 114 on the non-display area 103 of the flexible substrate 110 . The conductive adhesive member 190A may be partially overly coated on the protective layer 120 . That is, a portion of the protective layer 120 extending toward the display area 101 of the flexible substrate 110 may be covered with the polarizing layer 160 , and the protection extending toward the non-display area 103 of the flexible substrate 110 . A portion of the layer 120 may be covered with a conductive adhesive member 190A. However, in some examples, as shown in FIG. 5C , in the protective layer 120 , the conductive adhesive member 190A is covered on the protective layer 120 extending toward the non-display area 103 of the flexible substrate 110 . It may not be.

4 and 5A to 5C , a region in which the protective layer 120 is formed on the flexible substrate 110 is denoted by “H”, and a region covered by the polarizing layer 160 on the protective layer 120 . is denoted by “H1”, and the region covered by the conductive adhesive member 190A on the protective layer 120 is denoted by “H2”. In addition, the separation distance between the encapsulation layer 150 and the protective layer 120 on the flexible substrate 110 is denoted as “H3”, and the separation distance between the pad part 114 and the protective layer 120 on the flexible substrate 110 is “ H4".

6A to 6C are views illustrating a shape of a protective layer used in a flexible display device according to various examples of the present specification.

6A to 6C , the present examples are similar to the above-described flexible display apparatus 100 , but there is a difference in the shape of the protective layer 120 . Except for the shape of the protective layer 120 , it is the same as the above-described example of the flexible display device 100 , and the overlapping content will be omitted below.

In the present examples, uneven patterns 121 , 122 , and 123 may be formed on the side surface of the protective layer 120 in a direction from the display area 101 to the non-display area 103 of the flexible substrate 110 . . The concave-convex pattern 121, 122, 123 is formed of a concave-convex pattern 121 composed of a rectangular convex portion 121A and a concave portion 121B as shown in FIG. 6A, or a triangular convex portion 122A as shown in FIG. 6B. ) and the concave-convex pattern 122 composed of the concave portion 122B, or may be formed as the concave-convex pattern 123 composed of the semicircular convex portion 123A and the concave portion 123B as shown in FIG. 6C . Also, the uneven patterns 121 , 122 , and 123 may be disposed in the bending region 102 of the flexible substrate 110 . This has the effect of making bending more stable by reducing the reaction force (force repulsing when folding) caused by the protective layer 120 when the flexible substrate 110 is bent.

7 to 11 are views illustrating a manufacturing process of a flexible display device according to an example of the present specification.

A manufacturing process of the flexible display device according to an example of the present specification will be described with reference to FIGS. 7 to 11 .

As shown in FIG. 7 , a flexible substrate 210 is formed on the front surface of the carrier mother glass 10 . As an example, the flexible substrate 210 may be formed on the entirety except for the front edge of the carrier mother glass 10 . In addition, the organic light emitting device layer 254 may be formed on the flexible substrate 210 , and an encapsulation layer 250 for sealing the organic light emitting device layer 254 may be formed on the organic light emitting device layer 254 . In addition, on one surface of the flexible substrate 210 , a pad part 214 that is connected to a circuit film such as an FPCB and serves as a contact terminal for connecting the circuit film and a plurality of wiring lines to each other may be formed.

Next, as shown in FIG. 8 , a protective layer 220 may be formed on the flexible substrate 210 . In the example of the present specification, a protective layer, which can be referred to as a "micro-coating-layer", which is conventionally performed after the attachment process of a polarizing layer and a flexible circuit film is completed on a flexible substrate, is combined with a polarizing layer It can be formed before the attaching process of a flexible circuit film etc.

The protective layer 220 may have sufficient flexibility to be used in a bending region of the flexible substrate 210 . In addition, the protective layer 220 may be formed of a material having a specific modulus in order to protect the wiring in the bending region with a uniform and thin thickness. The protective layer 220 may be made of a material having a modulus of 0.2 GPa or more. In addition, the protective layer 220 may be made of polyimide (PI) having a high modulus, and preferably, it may be made of polyimide having a high modulus of 9 GPa.

The protective layer 220 may be disposed to be spaced apart from the encapsulation layer 250 of the flexible substrate 210 by a predetermined distance. In addition, the protective layer 220 may be formed on the flexible substrate 210 to have a uniform thickness. The thickness of the protective layer 220 may be 18 μm or more. For example, the thickness of the protective layer 220 may be substantially the same as the thickness of the encapsulation layer 250 (from the flexible substrate 210 to the top surface of the encapsulation layer 250 ).

In the example of the present specification, by using polyimide having a high modulus of 0.2 GPa or more as the protective layer 220 on the flexible substrate 210, the neutral plane is moved to the region where the wiring is configured, thereby preventing disconnection of the wiring. there is When a high modulus polyimide and a conventional low modulus resin are formed in the same thickness on a flexible substrate with wiring, the conventional low modulus resin has a neutral plane located at a lower level than the position where the wiring is configured, so that the wiring of the flexible substrate is difficult. Since it is subjected to tensile pressure, the possibility of disconnection of the wiring is high. However, in the high modulus polyimide, since the neutral plane is located above the position of the wiring, the wiring of the flexible substrate is subjected to compressive pressure, so that the possibility of disconnection of the wiring is low. As described above, by using polyimide having a high modulus of 0.2 GPa or more as the protective layer 120 , the thickness of the protective layer can be made thinner than that of the existing low modulus resin, thereby configuring a thin flexor display device. It can be advantageous to

Next, as shown in FIG. 9 , a polarization layer 260 may be attached to overlap a portion of the protective layer 220 on the encapsulation layer 250 and the protective layer 220 of the flexible substrate 210 . . At this time, the adhesive member 260A is formed between the polarization layer 260 and the encapsulation layer 250 , and the adhesive member 260A is protected in a form in which the step difference between the protective layer 220 and the polarization layer 260 is filled. It may be applied to cover one end of the layer 220 . To this end, the adhesive member 260A may be made of a soft material, and may be formed to be thicker than the thickness of the protective layer 220 . As such, when the protective layer 220 is spaced apart from the encapsulation layer 250 by a predetermined distance, its upper surface is covered by the polarizing layer 260 and the adhesive member 260A, so that the protective layer 220 is formed on the flexible substrate ( It is possible to prevent peeling from the 210 , thereby preventing moisture permeation between the protective layer 220 and the polarizing layer 260 and/or between the protective layer 220 and the encapsulation layer 250 . In addition, the flexible circuit film 290 may be attached to the pad part 214 of the flexible substrate 210 . In this case, a conductive adhesive member 290A is formed between the flexible circuit film 290 and the pad part 214 , and the conductive adhesive member 290A may be applied to cover at least a portion of the protective layer 220 . To this end, the conductive adhesive member 290A may include a conductive material and be thinner than the thickness of the protective layer 220 . As described above, when the protective layer 220 is spaced apart from the pad part PA by a predetermined distance, the upper surface thereof is covered by the conductive adhesive member 290A, thereby providing a gap between the protective layer 220 and the flexible circuit film 290 . It can prevent moisture permeation.

Next, as shown in FIG. 10 , the flexible substrate 210 may be detached (or separated) from the carrier mother glass 10 , and a first back plate is provided in the display area of the flexible substrate 210 . The 230A may be adhered, and the second support plate 230B may be adhered to the non-display area of the flexible substrate 210 .

Next, as shown in FIG. 11 , bending may be implemented by bending the flexible substrate 210 . A support so that the bent state of the flexible substrate 210 can be maintained between the first support plate 230A adhered to the display area of the bent flexible substrate 210 and the second support plate 230B adhered to the non-display area of the bent flexible substrate 210 . The member 240 may be disposed, the first support plate 230A may be attached to one surface of the support member 240 , and the second support plate 230B may be attached to the other surface of the support member 240 .

A flexible display apparatus according to an example of the present specification may be described as follows.

A flexible display device according to various examples of the present specification includes a flexible substrate including a first region, a second region, and a bending region, and a protective layer covering the bending region of the flexible substrate, wherein the protective layer includes the It may extend to at least a portion of the first area past a boundary between the first area and the bending area.

In the flexible display apparatus according to various examples of the present specification, the passivation layer may extend to at least a portion of the second area past a boundary between the second area and the bending area.

In the flexible display apparatus according to various examples of the present specification, the second area may overlap at least a portion of the first area, and the bending area may be bent between the first area and the second area with a constant curvature. .

In the flexible display device according to various examples of the present specification, the protective layer may be made of polyimide.

In the flexible display device according to various examples of the present specification, the protective layer may have a modulus of 0.2 GPa or more.

In the flexible display device according to various examples of the present specification, the protective layer may have a thickness of 18 μm or more.

In the flexible display device according to various examples of the present specification, a side surface of the protective layer may include an uneven pattern having a concave portion and a convex portion.

In the flexible display apparatus according to various examples of the present specification, the concave-convex pattern may be disposed in the bending area of the flexible substrate.

The flexible display apparatus according to various examples of the present specification includes a display unit on the first area, a pad unit on the second area, and signal lines on the bending area, wherein the protective layer is implemented on the signal lines can be

In the flexible display device according to various examples of the present specification, the protective layer may be spaced apart from the display unit.

The flexible display device according to various examples of the present specification may further include a polarization layer on the display unit, and the polarization layer may overlap a portion of the protective layer.

The flexible display device according to various examples of the present specification may further include an adhesive member interposed between the polarizing layer and the display unit and between the protective layer and the polarizing layer.

In the flexible display device according to various examples of the present specification, the protective layer may be spaced apart from the display unit, and the adhesive member may be filled in a space between the protective layer and the display unit.

In the flexible display device according to various examples of the present specification, the adhesive member may be made of a soft material, and may be formed to be thicker than the protective layer.

In the flexible display device according to various examples of the present specification, the protective layer may be spaced apart from the pad part.

The flexible display device according to various examples of the present specification may further include a flexible circuit film on the pad part, and the flexible circuit film may not overlap the protective layer.

The flexible display apparatus according to various examples of the present specification may further include a conductive adhesive member between the flexible circuit film and the pad part.

In the flexible display device according to various examples of the present specification, the conductive adhesive member may cover at least a portion of the protective layer.

In the flexible display device according to various examples of the present specification, the display unit includes an organic light emitting element and an encapsulation layer sealing the organic light emitting element, and is disposed between the encapsulation layer and the polarization layer of the display unit, and includes touch sensors. It further includes a touch sensor layer having a, wherein the touch sensor layer may be non-overlapping with the protective layer.

An electronic device according to various examples of the present specification includes a cover window, an image display device coupled to the cover window, and a housing supporting the cover window and accommodating the image display device, wherein the image display device includes a first A flexible substrate including a region, a second region, and a bending region, and a protective layer covering the bending region of the flexible substrate, wherein the protective layer passes through a boundary between the first region and the bending region, and the first region A flexible display device extending to at least a part of the area may be included.

Features, structures, effects, etc. described in the above-described examples of the present specification are included in at least one example of the present specification, and are not necessarily limited to only one example. Furthermore, features, structures, effects, etc. illustrated in at least one example of the present specification may be combined or modified with respect to other examples by those of ordinary skill in the art to which this specification belongs. Accordingly, the contents related to such combinations and modifications should be interpreted as being included in the scope of the present specification.

The present specification described above is not limited to the above-described embodiments and the accompanying drawings, and it is common in the technical field to which this specification belongs that various substitutions, modifications and changes are possible within the scope without departing from the technical details of the present specification. It will be clear to those who have the knowledge of Therefore, the scope of the present specification is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be construed as being included in the scope of the present specification.

100, 200: flexible display device
110, 210: flexible substrate
101: active area
102: bending area
103: non active area
120, 220: protective layer
130A, 130B, 230A, 230B: back plate
140: support member
154, 254: organic light emitting device layer
150, 250: encapsulation layer
160, 260: polarizing layer
170: touch sensor layer
180: cover window

Claims (20)

a flexible substrate including a first region, a second region, and a bending region; and
a protective layer covering the bending region of the flexible substrate;
The protective layer extends to at least a portion of the first area past a boundary between the first area and the bending area. According to claim 1,
The protective layer extends to at least a portion of the second area past a boundary between the second area and the bending area. According to claim 1,
the second region overlaps at least a portion of the first region;
The bending area is bent with a constant curvature between the first area and the second area. According to claim 1,
The protective layer is made of polyimide (polyimide), a flexible display device. 5. The method of claim 4,
The protective layer has a modulus of 0.2 GPa or more, a flexible display device. 5. The method of claim 4,
The protective layer has a thickness of 18 μm or more, a flexible display device. According to claim 1,
The side surface of the protective layer includes a concave-convex pattern having concave and convex portions. 8. The method of claim 7,
The concave-convex pattern is disposed in the bending area of the flexible substrate. According to claim 1,
a display unit on the first area;
a pad part on the second area; and
signal lines on the bending area;
wherein the protective layer is implemented on the signal lines. 10. The method of claim 9,
The protective layer is spaced apart from the display unit, a flexible display device. 10. The method of claim 9,
Further comprising a polarizing layer on the display unit,
The polarizing layer overlaps a portion of the protective layer, the flexible display device. 12. The method of claim 11,
The flexible display device further comprising an adhesive member interposed between the polarizing layer and the display unit and between the protective layer and the polarizing layer. 13. The method of claim 12,
The protective layer is spaced apart from the display unit,
and the adhesive member is filled in a space between the protective layer and the display unit. 13. The method of claim 12,
The adhesive member is made of a soft material and is formed to be thicker than a thickness of the protective layer. 10. The method of claim 9,
and the protective layer is spaced apart from the pad part. 16. The method of claim 15,
Further comprising a flexible circuit film on the pad portion,
The flexible circuit film is non-overlapping with the protective layer, a flexible display device. 17. The method of claim 16,
The flexible display device further comprising a conductive adhesive member between the flexible circuit film and the pad part. 18. The method of claim 17,
The conductive adhesive member covers at least a portion of the protective layer. 12. The method of claim 11,
The display unit includes an organic light emitting device and an encapsulation layer sealing the organic light emitting device,
It is disposed between the encapsulation layer and the polarizing layer of the display unit, further comprising a touch sensor layer having touch sensors,
The touch sensor layer is non-overlapping with the protective layer, a flexible display device. cover window;
an image display device coupled to the cover window; and
and a housing supporting the cover window and accommodating the image display device,
The video display device, an electronic device comprising the flexible display device according to any one of claims 1 to 19.

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