KR102589905B1 - Narrow bezel flexible electroluminesence display and methed for manufacturing the same - Google Patents

Abstract

This application relates to a narrow bezel flexible electroluminescent display device. A narrow-bezel flexible electroluminescent display device according to an embodiment of the present application includes a flexible substrate, a pad portion, a rigid engraving plate, a pad cross section, and a conductive terminal. The flexible substrate has a display area and a non-display area surrounding the display area. The pad portion is disposed in a part of the non-display area. The rigid engraving plate is disposed in a partial area of the lower surface of the flexible substrate. The pad cross section is exposed to the side wall of the pad portion. The conductive terminal is applied to the end face of the pad.

Description

Narrow bezel flexible electroluminescent display device and manufacturing method thereof {NARROW BEZEL FLEXIBLE ELECTROLUMINESENCE DISPLAY AND METHED FOR MANUFACTURING THE SAME}

This application relates to a narrow bezel flexible electroluminescent display device and a method of manufacturing the same. In particular, the present application is a flexible electroluminescent display device having a narrow bezel structure in which a pad portion connected to a driving integrated circuit (IC) is disposed on the sidewall of the substrate to minimize the bezel area on all sides of the display panel, and a method of manufacturing the same. It's about.

Among display devices, electroluminescent displays are self-luminous, have excellent viewing angles and contrast ratios, do not require a separate backlight, can be lightweight and thin, and have advantages in low power consumption. In particular, among electroluminescent display devices, organic light emitting display devices have the advantages of being capable of driving at low direct current voltages, fast response speeds, and low manufacturing costs.

An electroluminescent display device includes a plurality of electroluminescent diodes. An electroluminescent diode includes an anode electrode, a light-emitting layer formed on the anode electrode, and a cathode electrode formed on the light-emitting layer. When a high potential voltage is applied to the anode electrode and a low potential voltage is applied to the cathode electrode, holes are moved to the anode electrode and electrons are moved to the cathode electrode, respectively, to the light emitting layer. When holes and electrons combine in the light-emitting layer, excitons are formed during the excitation process, and light is generated due to the energy from the excitons. An electroluminescent display device displays images by electrically controlling the amount of light generated from the light-emitting layer of a plurality of electroluminescent diodes individually divided by banks.

Electroluminescence display devices can implement ultra-thin display devices, making it easy to develop display devices suitable for various special purposes, such as flexible display devices. However, it is not easy to implement a narrow bezel display device with a large ratio of effective information display area on the display surface. For example, there is a limit to reducing the area of the pad connection area for providing video information to the display panel. This is not a problem with the material of the display device, but a problem with the connection structure between the display device and the external driver.

The technical task of this application is to provide a flexible electroluminescent display device with a minimized bezel area and a manufacturing method thereof. In addition, the technical task of this application is to provide a flexible electroluminescent display device and a manufacturing method thereof in which the bezel area is minimized by connecting a flexible circuit board at one end surface of the flexible substrate.

A narrow-bezel flexible electroluminescent display device according to an embodiment of the present application includes a flexible substrate, a pad portion, a rigid engraving plate, a pad cross section, and a conductive terminal. The flexible substrate has a display area and a non-display area surrounding the display area. The pad portion is disposed in a part of the non-display area. The rigid engraving plate is disposed in a partial area of the lower surface of the flexible substrate. The pad cross section is exposed to the side wall of the pad portion. The conductive terminal is applied to the end face of the pad.

For example, it further includes a flexible circuit board and a driving integrated circuit. The flexible circuit board is connected to the conductive terminal. The driving integrated circuit is mounted on a flexible circuit board.

For example, the flexible circuit board includes a pad terminal disposed on one short side, and a link wire connected from the pad terminal to the driving integrated circuit. The pad terminal is connected in one-to-one correspondence with the conductive terminal through an anisotropic conductive film.

In one example, a flexible circuit board is bent and attached to the bottom surface of a rigid piece plate.

For example, it further includes a back film bonded to the bottom of the flexible substrate.

In one example, the back film extends from the lower surface of the flexible substrate and covers the lower surface of the rigid engraving plate.

For example, the end side of the rigid piece plate is disposed to coincide with the end side of the flexible substrate.

For example, the non-display area further includes a dam structure surrounding the display area. The pad portion is disposed outside the dam structure.

For example, the display area includes scan lines, data lines, driving current lines, and pixels. The scan wiring runs in the first direction of the flexible substrate. The data wiring and the pixel driving power supply wiring run in a second direction different from the first direction. Pixels are defined by scan wiring, data wiring, and pixel driving power wiring, and are arranged in a matrix manner. The non-display area includes a gate driver and pad terminals. The gate driver is connected to the scan wiring. The pad terminals are connected to the data line and the pixel driving power line. A rigid piece plate is disposed at the bottom of the pad terminals.

In one example, a rigid piece plate has a trapezoidal cross-section that includes a vertical side, an inclined side, and a horizontal bottom. The vertical side is disposed on the side wall and extension of the pad area. The inclined side surface has a certain angle greater than the vertical angle with the lower surface of the flexible substrate. The horizontal lower surface is a surface parallel to the lower surface of the flexible substrate connecting the vertical side and the inclined side.

Additionally, the flexible display device manufacturing method according to the present application includes forming a flexible substrate on a rigid substrate, forming a display element layer, and forming a rigid engraving plate. In forming the display element layer, a display area and a non-display area are formed on the flexible substrate. The step of forming the rigid engraving plate removes the remainder of the rigid substrate, leaving a portion of the rigid substrate in some areas of the non-display area on the lower surface of the flexible substrate.

For example, the rigid piece plate is formed so that the end side of the rigid piece plate coincides with the end side of the flexible substrate.

For example, before forming the flexible substrate, the method further includes applying a sacrificial layer on the rigid substrate. In the step of forming a rigid engraving plate, the remainder of the rigid substrate is separated from the flexible substrate by irradiating a laser to the sacrificial layer applied to the remainder of the rigid substrate.

For example, the step of forming the display element layer includes forming a wire disposed in the display area, a link wire disposed in the non-display area and extending from the wire, and a pad connected to an end of the link wire. The flexible substrate and the rigid substrate are cut across the center of the pad to expose the cross section of the pad.

For example, the method further includes applying a conductive terminal to the cross section of the pad and connecting a flexible circuit board to the conductive terminal.

The electroluminescent display device according to the present application can achieve a narrow bezel structure on all four sides of the display panel by being connected to an external driving circuit at the side end surface rather than the upper surface of the display panel. In addition, the electroluminescent display device according to the present application has a flexible feature in all display areas because the rigid engraving plate is disposed limited to the non-display area only at the lower part of one side where the pad portion is disposed.

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

1 is a plan view showing a narrow-bezel flexible electroluminescent display device according to an embodiment of the present application.
FIG. 2 is a cross-sectional view taken along line II' of FIG. 1 illustrating the structure of a narrow-bezel flexible electroluminescent display device according to an embodiment of the present application.
Figure 3 is an enlarged perspective view showing a connection structure between a pad portion and a flexible circuit film having a driving integrated circuit in a narrow-bezel flexible electroluminescent display device according to an embodiment of the present application.
Figure 4 is a plan view showing a narrow-bezel flexible electroluminescent display device according to another embodiment of the present application.
Figure 5 is a plan view showing a narrow-bezel flexible electroluminescent display device according to another embodiment of the present application.
6A and 6B are diagrams showing a narrow-bezel flexible electroluminescent display device according to an example of the present application.
7A and 7B are diagrams showing a narrow-bezel flexible electroluminescent display device according to an example of the present application.
Figure 8 is a flowchart showing a process for manufacturing a narrow-bezel flexible electroluminescent display device according to an example of the present application.

The advantages and features of the present application and methods for achieving them will become clear by referring to examples described in detail below along with the accompanying drawings. However, the present application is not limited to the examples disclosed below and will be implemented in various different forms, and only the examples of the present application ensure that the disclosure of the present application is complete, and are commonly used in the technical field to which the invention of the present application pertains. It is provided to fully inform those with knowledge of the scope of the invention, and the invention of this application is only defined by the scope of the claims.

The shape, size, ratio, angle, number, etc. disclosed in the drawings for explaining an example of the present application are illustrative, and the present application is not limited to the matters shown. Like reference numerals refer to like elements throughout the specification. Additionally, in describing examples of the present application, if it is determined that detailed descriptions of related known technologies may unnecessarily obscure the gist of the present application, the detailed descriptions will be omitted.

When 'includes', 'has', 'consists of', 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 plural is included unless specifically stated otherwise.

When interpreting a component, it is interpreted to include the margin of error even if there is no separate explicit description.

In the case of a description of a positional relationship, for example, if the positional relationship of two parts is described as 'on top', 'on the top', 'on the bottom', 'next to', etc., 'immediately' Alternatively, there may be one or more other parts placed between the two parts, unless 'directly' is used.

In the case of a description of a temporal relationship, for example, if a temporal relationship is described as 'after', 'successfully after', 'after', 'before', etc., 'immediately' or 'directly' Unless used, non-consecutive cases may also be included.

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

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

Each feature of the various examples of the present application can be combined or combined with each other partially or entirely, and various technological interconnections and operations are possible, and each example can be implemented independently of each other or together in a related relationship. .

Hereinafter, an example of an electroluminescent display device according to the present application will be described in detail with reference to the attached drawings. In adding reference numerals to components in each drawing, identical components may have the same reference numerals as much as possible even if they are shown in different drawings.

1 is a plan view showing a narrow-bezel flexible electroluminescent display device according to an embodiment of the present application. Referring to FIG. 1, the narrow-bezel flexible electroluminescent display device according to the present application includes a flexible substrate (FS), a pixel (P), a common power line (CPL), a gate driving circuit 200, a dam structure (DM), and It may include a pad portion (PP).

The flexible substrate (FS) is a base substrate (or base layer) and includes a plastic material or a glass material. Even if it is made of glass, it has very high flexibility when formed extremely thin, so it can be applied to flexible display devices. The flexible substrate FS according to an example may have a square shape in plan, a square shape in which each corner is rounded with a constant radius of curvature, or a non-square shape with at least six sides. Here, the substrate SUB having a non-rectangular shape may include at least one protrusion or at least one notch portion.

The flexible substrate FS according to one example may be divided into a display area (AA) and a non-display area (IA). The display area AA is provided in the middle area of the flexible substrate FS and may be defined as an area for displaying an image. The display area AA according to one example may have a rectangular shape in plan, a rectangular shape in which each corner is rounded to have a constant radius of curvature, or a non-rectangular shape with at least six sides. Here, the display area AA having a non-rectangular shape may include at least one protrusion or at least one notch.

The non-display area (IA) is provided at an edge area of the flexible substrate (FS) to surround the display area (AA), and may be defined as an area where an image is not displayed or a peripheral area. The non-display area (IA) according to an example includes a first non-display area (IA1) provided on the first edge of the flexible substrate (FS), and a second edge of the flexible substrate (FS) parallel to the first non-display area (IA1). A second non-display area (IA2) provided in, a third non-display area (IA3) provided on the third edge of the flexible substrate (FS), and a third non-display area (IA3) provided on the fourth edge of the flexible substrate (FS) parallel to the third non-display area. It may include a fourth non-display area (IA4). For example, the first non-display area (IA1) is the upper (or lower) edge area of the flexible substrate (FS), the second non-display area (IA2) is the lower (or upper) edge area of the flexible substrate (FS), The third non-display area (IA3) may be the left (or right) edge area of the flexible substrate (FS), and the fourth non-display area (IA4) may be the right (or left) edge area of the flexible substrate (FS). It is not necessarily limited to this.

The pixel P may be provided on the display area AA of the flexible substrate FS. According to one example, a plurality of pixels P may be arranged in a matrix arrangement and may be arranged in the display area AA. A pixel (P) may be defined by a scan line (SL), a data line (DL), and a pixel driving power line (PL).

The scan lines SL extend long along the first direction (X) and are arranged at regular intervals along the second direction (Y) that intersects the first direction (X). The display area AA of the flexible substrate FS includes a plurality of scan lines SL parallel to the first direction X and spaced apart from each other along the second direction Y. Here, the first direction (X) may be defined as the horizontal direction of the flexible substrate (FS), and the second direction (Y) may be defined as the vertical direction of the flexible substrate (FS), but is not necessarily limited thereto. It can also be defined the other way around.

The data line DL extends long along the second direction (Y) and is arranged at regular intervals along the first direction (X). The display area AA of the flexible substrate FS includes a plurality of data lines DL parallel to the second direction Y and spaced apart from each other along the first direction X.

The pixel driving power line PL is disposed on the flexible substrate FS to be parallel to the data line DL. The display area AA of the flexible substrate FS includes a plurality of pixel driving power lines PL parallel to the data lines DL. In some cases, the pixel driving power line PL may be arranged to be parallel to the scan line SL.

The pixel P according to one example may be arranged to have a stripe structure on the display area AA. In this case, one unit pixel may include a red pixel, a green pixel, and a blue pixel, and one unit pixel may further include a white pixel.

The pixel P according to another example may be arranged to have a pentile structure on the display area AA. In this case, one unit pixel may include at least one red pixel, at least two green pixels, and at least one blue pixel arranged in a planar polygonal shape. For example, one unit pixel with a pentile structure may be arranged so that one red pixel, two green pixels, and one blue pixel have an octagonal shape on a two-dimensional surface, and in this case, the blue pixel is relatively the largest. It may have a large aperture area (or light emitting area), and the green pixel may have a relatively small aperture area.

The pixel (P) includes a pixel circuit (PC) electrically connected to the scan wire (SL), data wire (DL), and pixel driving power wire (PL), and a light emitting element (ED) electrically connected to the pixel circuit (PC). It can be included.

The pixel circuit (PC) responds to a scan signal supplied from at least one scan wire (SL) and outputs a signal from the pixel driving power wire (PL) to the light emitting element (ED) based on the data voltage supplied from the adjacent data wire (DL). Controls the flowing current (Ied).

The pixel circuit (PC) according to one example may include at least two thin film transistors and one capacitor. For example, the pixel circuit (PC) according to one example drives a driving thin film transistor that supplies a data current (Ied) based on a data voltage to the light emitting element (ED), and a data voltage supplied from the data line (DL). It may include a switching thin film transistor that supplies the thin film transistor, and a capacitor that stores the gate-source voltage of the driving thin film transistor.

A pixel circuit (PC) according to another example may include at least three thin film transistors and at least one capacitor. For example, the pixel circuit (PC) according to one example may include a current supply circuit, a data supply circuit, and a compensation circuit according to the operation (or function) of each of at least three thin film transistors. Here, the current supply circuit may include a driving thin film transistor that supplies a data current (Ied) based on the data voltage to the light emitting element (ED). The data supply circuit may include at least one switching thin film transistor that supplies the data voltage supplied from the data line DL to the current supply circuit in response to at least one scan signal. The compensation circuit may include at least one compensation thin film transistor that compensates for changes in characteristic values (threshold voltage and/or mobility) of the driving thin film transistor in response to at least one scan signal.

The light emitting element (ED) emits light by the data current (Ied) supplied from the pixel circuit (PC) and emits light with a brightness corresponding to the data current (Ied). In this case, the data current Ied may flow from the pixel driving power line PL to the common power line CPL through the driving thin film transistor and the light emitting element ED.

The light emitting device (ED) according to one example includes a pixel driving electrode (or first electrode or anode) electrically connected to the pixel circuit (PC), a light emitting layer formed on the pixel driving electrode, and a common electrode (or a first electrode) electrically connected to the light emitting layer. 2 electrode or cathode).

The common power line (CPL) is disposed on the non-display area (IA) of the flexible substrate (FS) and is electrically connected to the common electrode disposed on the display area (AA). The common power line (CPL) according to one example has a constant line width and is disposed along the second to fourth non-display areas (IA2, IA3, IA4) adjacent to the display area (IA) of the flexible substrate (FS), It surrounds the remaining portion except for a portion of the display area (AA) adjacent to the first non-display area (IA1) of the flexible substrate (FS). One end of the common power line (CPL) may be disposed on one side of the first non-display area (IA1), and the other end of the common power line (CPL) may be disposed on the other side of the first non-display area (IA1). Additionally, the area between one end and the other end of the common power line (CPL) may be arranged to surround the second to fourth non-display areas (IA2, IA3, IA4). Accordingly, the common power line CPL according to one example may have a '∩' shape with one side open corresponding to the first non-display area IA1 of the flexible substrate FS in plan view.

The pad portion PP may include a plurality of pads provided in the non-display area IA of the flexible substrate FS. The pad portion PP according to an example includes a plurality of common power supply pads, a plurality of data pads, a plurality of power supply pads, and a plurality of control signal input pads provided in the first non-display area IA1 of the flexible substrate FS. It may include etc.

The gate driving circuit 200 is provided in the third non-display area (IA3) and/or the fourth non-display area (IA4) of the flexible substrate (FS) and has a one-to-one relationship with the scan lines (SL) provided in the display area (AA). connected. The gate driving circuit 200 is integrated in the third non-display area (IA3) and/or fourth non-display area (IA4) of the flexible substrate (FS) along with the manufacturing process of the pixel (P), that is, the manufacturing process of the thin film transistor. do. The gate driving circuit 200 generates a scan signal based on the gate control signal supplied from the driving integrated circuit 300 and outputs it in a certain order, thereby driving each of the plurality of scan lines SL in a certain order. The gate driving circuit 200 according to one example may include a shift register.

The dam structure DM is provided in the first non-display area IA1, the second non-display area IA2, the third non-display area IA3, and the fourth non-display area IA4 of the flexible substrate FS. It may have a closed curve structure surrounding the area (AA). For example, the dam structure DM may be disposed outside the common power line CPL and thus may be located at the outermost portion of the flexible substrate FS. The pad portion PP is preferably disposed in an outer area of the dam structure DM.

Although Figure 1 illustrates the case where the dam structure (DM) is placed at the outermost edge, it is not limited to this. As another example, the dam structure DM may be disposed between the common power line CPL and the gate driving circuit 200. As another example, the dam structure DM may be disposed between the display area AA and the gate driving circuit 200.

The narrow-bezel flexible electroluminescent display device according to the present application may further include a driving integrated circuit 300 mounted on the flexible circuit film (TC) and electrically connected to the pad portion (PP). The flexible circuit film (TC) can be attached between the pad portion (PP) of the flexible substrate (FS) and an external printed circuit board (not shown) by a film attachment process, and is used as a tape carrier package (Tape Carrier Package). ) or it can be done in a chip-on-film method.

The driving integrated circuit 300 may be mounted on a flexible circuit film TC and connected to the pad portion PP through the flexible circuit film TC. The output terminals of the driving integrated circuit 300 are electrically connected to the pad portion PP and thus are electrically connected to a plurality of data lines DL and a plurality of pixel driving power lines PL provided in the display area AA. .

The driving integrated circuit 300 receives various power sources, timing synchronization signals, and digital image data input from the display driving circuit unit (or host circuit), and generates a gate control signal according to the timing synchronization signal. The driving integrated circuit 300 controls the driving of the gate driving circuit 200 through the pad portion PP, and at the same time converts digital image data into analog pixel data voltage and supplies it to the corresponding data line DL. do.

Although not shown in the drawing, an encapsulation layer may be further included. The encapsulation layer may be formed on the substrate SUB to surround the top and side surfaces of the display area AA and the common power line CPL. Meanwhile, the encapsulation layer may expose one end and the other end of the common power line CPL in the first non-display area IA1. The encapsulation layer can prevent oxygen or moisture from penetrating into the light emitting element (ED) provided in the display area (AA). The encapsulation layer according to one example may include at least one inorganic film. An encapsulation layer according to another example may include a plurality of inorganic films and an organic film between the plurality of inorganic films.

Hereinafter, with further reference to FIG. 2, the cross-sectional structure of the narrow-bezel flexible electroluminescent display device according to an embodiment of the present application will be described in detail. FIG. 2 is a cross-sectional view taken along line II' of FIG. 1 illustrating the structure of a narrow-bezel flexible electroluminescent display device according to an embodiment of the present application.

The narrow-bezel flexible electroluminescent display device according to an embodiment of the present application includes a flexible substrate (FS), a pixel array layer 120, an encapsulation layer 130, a barrier film (BF), an optical film (POL), and a rigid It includes a piece plate (GS), a back film (BP), a conductive terminal (AP), a flexible circuit film (TC), and a driving integrated circuit 300.

The flexible substrate FS includes a plastic material or a glass material as a base layer. The flexible substrate FS according to one example may include an opaque or colored polyimide material. For example, a flexible substrate (FS) made of polyimide may be a cured product of polyimide resin coated to a certain thickness on the entire surface of a release layer provided on a relatively thick carrier substrate. In this case, the carrier glass substrate is separated from the flexible substrate FS by releasing the release layer using a laser release process.

The flexible substrate FS according to another example may be a flexible glass substrate. For example, the flexible substrate FS made of glass may be a thin glass substrate with a thickness of 100 micrometers or less, or a carrier glass substrate etched to have a thickness of 100 micrometers or less through a substrate etching process.

The flexible substrate FS may include a display area AA and a non-display area IA surrounding the display area AA. A pixel array layer 120, an encapsulation layer 130, a barrier film (BF), and an optical film (POL) may be sequentially stacked on the flexible substrate FS.

A buffer film (not shown) may be formed on the upper surface of the flexible substrate FS. The buffer film is formed on one side of the flexible substrate (FS) to block moisture penetrating into the pixel array layer 120 through the flexible substrate (FS), which is vulnerable to moisture permeation. A buffer film according to one example may be composed of a plurality of inorganic films stacked alternately. For example, the buffer layer may be formed as a multilayer in which one or more inorganic layers of silicon oxide (SiOx), silicon nitride (SiNx), and silicon oxynitride (SiON) are alternately stacked. The buffer film may be omitted.

The pixel array layer 120 may include a thin film transistor layer, a planarization layer, a bank pattern, and a light emitting element (ED). The thin film transistor layer is connected to a plurality of pixels P defined in the display area AA of the flexible substrate FS and the gate driving circuit 200 defined in the fourth non-display area IA4 of the flexible substrate FS. It can be provided.

The thin film transistor layer according to one example includes a thin film transistor (T), a gate insulating layer (GI), and an interlayer insulating layer (ILD). Here, the thin film transistor T shown in FIG. 2 may be a driving thin film transistor electrically connected to the light emitting device ED.

The thin film transistor (T) includes a semiconductor layer (A), a gate electrode (G), a source electrode (S), and a drain electrode (D) formed on a flexible substrate (FS) or a buffer film. In FIG. 2, the thin film transistor (T) shows a top gate (top gate) structure in which the gate electrode (G) is located on top of the semiconductor layer (A), but it is not necessarily limited to this. As another example, the thin film transistor (T) has a bottom gate structure in which the gate electrode (G) is located at the bottom of the semiconductor layer (A), or the gate electrode (G) is located at the top and the bottom of the semiconductor layer (A). It may have a double gate structure located all at the bottom.

The semiconductor layer (A) may be formed on the flexible substrate (FS) or a buffer film. The semiconductor layer (A) may include a silicon-based semiconductor material, an oxide-based semiconductor material, or an organic-based semiconductor material, and may have a single-layer structure or a multi-layer structure. A light blocking layer may be additionally formed between the buffer film and the semiconductor layer (A) to block external light incident on the semiconductor layer (A).

The gate insulating film GI may be formed on the entire substrate SUB to cover the semiconductor layer A. The gate insulating layer GI may be formed of an inorganic layer, for example, a silicon oxide layer (SiOx), a silicon nitride layer (SiNx), or a multilayer thereof.

The gate electrode (G) may be formed on the gate insulating film (GI) to overlap the semiconductor layer (A). The gate electrode (G) may be formed together with the scan line (SL). The gate electrode (G) according to one example is made of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu). It can be formed as a single layer or multiple layers made of any one or an alloy thereof.

The interlayer insulating layer (ILD) may be formed on the entire substrate (SUB) to cover the gate electrode (G) and the gate insulating layer (GI). The interlayer insulating layer (ILD) provides a flat surface on the gate electrode (G) and the gate insulating layer (GI).

The source electrode (S) and the drain electrode (D) may be formed on the interlayer insulating layer (ILD) to overlap the semiconductor layer (A) with the gate electrode (G) interposed therebetween. The source electrode (S) and the drain electrode (D) may be formed together with the data line (DL), the pixel driving power line (PL), and the common power line (CPL). That is, each of the source electrode (S), drain electrode (D), data line (DL), pixel driving power line (PL), and common power line (CPL) is formed simultaneously by a patterning process for the source and drain electrode material.

Each of the source electrode S and the drain electrode D may be connected to the semiconductor layer A through an electrode contact hole penetrating the interlayer insulating layer ILD and the gate insulating layer GI. The source electrode (S) and drain electrode (D) are made of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu). ) may be formed as a single layer or multiple layers made of any one or an alloy thereof. Here, the source electrode S of the thin film transistor T shown in FIG. 2 may be electrically connected to the pixel driving power line PL.

In this way, the thin film transistor T provided in the pixel P of the substrate SUB constitutes the pixel circuit PC. Additionally, the gate driving circuit 200 disposed in the fourth non-display area (IA4) of the flexible substrate (FS) may include a thin film transistor that is the same as or similar to the thin film transistor (T) provided in the pixel (P).

The planarization layer (PLN) is formed on the entire flexible substrate (FS) to cover the thin film transistor layer. The planarization layer (PLN) provides a planar surface on the thin film transistor layer. The planarization layer (PLN) according to one example is an organic material such as acryl resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin. It can be formed into a membrane. The planarization layer (PLN) according to another example may include a pixel contact hole (PH) for exposing the drain electrode (D) of the driving thin film transistor provided in the pixel (P).

The bank pattern BN is disposed on the planarization layer PLN to define an opening area (or light-emitting area) within the pixel P of the display area AA. This bank pattern (BN) may also be expressed as a pixel defining layer.

The light emitting element (ED) includes a pixel driving electrode (AE), a light emitting layer (EL), and a common electrode (CE). The pixel driving electrode (AE) is formed on the planarization layer (PLN) and is electrically connected to the drain electrode (D) of the driving thin film transistor through the pixel contact hole (PH) provided in the planarization layer (PLN). In this case, the remaining edge portions except for the middle portion of the pixel driving electrode AE that overlaps the opening area of the pixel P may be covered by the bank pattern BN. The bank pattern BN may define the opening area of the pixel P by covering the edge of the pixel driving electrode AE.

The pixel driving electrode AE according to one example may include a metal material with high reflectivity. For example, the pixel driving electrode (AE) has a stacked structure of aluminum (Al) and titanium (Ti) (Ti/Al/Ti), a stacked structure of aluminum (Al) and ITO (ITO/Al/ITO), and APC ( It is formed in a multi-layer structure such as Ag/Pd/Cu) alloy, and a laminated structure of APC alloy and ITO (ITO/APC/ITO), or silver (Ag), aluminum (Al), molybdenum (Mo), and gold (Au) , it may include a single-layer structure made of any one material selected from magnesium (Mg), calcium (Ca), or barium (Ba), or an alloy material of two or more materials.

The light emitting layer EL is formed throughout the display area AA of the flexible substrate FS to cover the pixel driving electrode AE and the bank pattern BN. The light emitting layer (EL) according to one example may include two or more light emitting units vertically stacked to emit white light. For example, the light emitting layer EL according to one example may include a first light emitting unit and a second light emitting unit for emitting white light by mixing the first light and the second light. Here, the first light emitting part emits the first light and may include any one of a blue light emitting part, a green light emitting part, a red light emitting part, a yellow light emitting part, and a yellow green light emitting part. The second light emitting unit may include a blue light emitting unit, a green light emitting unit, a red light emitting unit, a yellow light emitting unit, and a light emitting unit that emits second light having a complementary color relationship with the first light among yellow green.

The light emitting layer EL according to another example may include any one of a blue light emitting part, a green light emitting part, and a red light emitting part for emitting color light corresponding to the color set in the pixel P. For example, the light emitting layer (EL) according to another example may include any one of an organic light emitting layer, an inorganic light emitting layer, and a quantum dot light emitting layer, or may include a stacked or mixed structure of an organic light emitting layer (or an inorganic light emitting layer) and a quantum dot light emitting layer.

The common electrode (CE) is formed to be electrically connected to the light emitting layer (EL). The common electrode (CE) is formed throughout the display area (AA) of the flexible substrate (FS) to be commonly connected to the light emitting layer (EL) provided in each pixel (P).

The common electrode (CE) according to one example may include a transparent conductive material or a translucent conductive material that can transmit light. When the common electrode (CE) is formed of a transflective conductive material, the emission efficiency of light emitted from the light emitting device (ED) can be increased through a micro cavity structure. The transflective conductive material according to one example may include magnesium (Mg), silver (Ag), or an alloy of magnesium (Mg) and silver (Ag). Additionally, a capping layer may be further formed on the common electrode (CE) to improve light emission efficiency by adjusting the refractive index of light emitted from the light emitting device (ED).

A plurality of spacers may be distributed and disposed in an opening area within the display area AA, that is, an area where the light emitting element ED is not disposed. The spacer may be used to prevent the screen mask and the substrate from directly contacting each other during the process of depositing the light emitting layer (EL). The spacer is disposed on the bank pattern BN, and may be applied so that the light emitting layer EL and the common electrode CE pass over the spacer disposed inside the display area AA. In some cases, the light emitting layer (EL) and/or the common electrode (CE) may not pass over the spacer. Since the spacer is placed only in a part of the bank pattern (BN) inside the display area (AA), even if the common electrode (CE) does not go over the spacer, the common electrode (CE) covers the entire display area (AA) and is connected It has a structure.

The encapsulation layer 130 is formed to surround both the top and side surfaces of the pixel array layer 120. The encapsulation layer 130 serves to prevent oxygen or moisture from penetrating into the light emitting device (ED).

The encapsulation layer 130 according to an example includes a first inorganic encapsulation layer (PAS1), an organic encapsulation layer (PCL) on the first inorganic encapsulation layer (PAS1), and a second inorganic encapsulation layer (PAS2) on the organic encapsulation layer (PCL). may include. The first inorganic encapsulation layer (PAS1) and the second inorganic encapsulation layer (PAS2) serve to block the penetration of moisture or oxygen. According to one example, the first inorganic encapsulation layer (PAS1) and the second inorganic encapsulation layer (PAS2) are made of silicon nitride, aluminum nitride, zirconium nitride, titanium nitride, hafnium nitride, tantalum nitride, silicon oxide, aluminum oxide, or titanium oxide. It may be made of inorganic materials. The first inorganic encapsulation layer (PAS1) and the second inorganic encapsulation layer (PAS2) may be formed by a chemical vapor deposition process or an atomic layer deposition process.

The organic encapsulation layer (PCL) is surrounded by the first inorganic encapsulation layer (PAS1) and the second inorganic encapsulation layer (PAS2). The organic encapsulation layer (PCL) is relatively thick compared to the first inorganic encapsulation layer (PAS1) and/or the second inorganic encapsulation layer (PAS2) to adsorb and/or block particles that may occur during the manufacturing process. It can be formed as The organic encapsulation layer (PCL) may be made of an organic material such as silicon oxycarbon (SiOCz) acrylic or epoxy-based resin. The organic encapsulation layer (PCL) may be formed by a coating process, for example, an inkjet coating process or a slit coating process.

A barrier film (BF) and an optical film (POL) may be sequentially stacked on the encapsulation layer 130 on the flexible substrate FS. The barrier film (BF) is a film laminated on the encapsulation layer 130 and is intended to protect all devices below it. Accordingly, it may have a size that covers not only the entire display area AA but also most of the non-display area IA. For example, as shown in FIG. 5 , the entire upper surface of the flexible substrate FS may be covered except for a portion of the first non-display area IA1 where the pad portion PP is disposed.

An optical film (POL) is laminated on the upper surface of the barrier film (BF) to prevent reflection of external light. The optical film POL may be used to prevent color from being deteriorated when external light is reflected by a metal layer disposed in the display area AA. Therefore, it is desirable to arrange the optical film (POL) so as to completely cover at least the display area (AA). The optical film (POL) may have a slightly smaller size than the barrier film (BF).

A rigid engraving plate (GS) is disposed on the lower surface of the flexible substrate (FS). The rigid engraving plate GS is disposed in the first non-display area IA1 where the pad portion PP is disposed on the flexible substrate FS. Additionally, the rigid piece plate GS may have a size corresponding to at least the pad portion PP. The rigid engraving plate GS may have the same size as the first non-display area IA1 where the pad portion PP is disposed. For example, the length of the rigid plate GS may be equal to or slightly larger than the length of the pad portion PP, and the width of the rigid plate GS may be the width of the pad portion PP (pad It can have a width equal to or slightly larger than the length of . As another example, the rigid engraving plate GS has a width from the boundary line between the display area AA and the first non-display area IA1 to the outer end of the first non-display area IA1, and a length of the pad portion PP. It can have a slightly longer length.

The rigid engraving plate (GS) can be manufactured and bonded separately, but it is preferable to form it using a rigid glass substrate that is temporarily attached to the bottom of the flexible substrate (FS) and then removed after the display panel is completely formed.

A back film (BF) may be coupled to the rear surface of the flexible substrate (FS) in the thickness direction (Z) of the flexible substrate (FS) having a rigid engraving plate (GS) on one lower surface. The back film (BF) maintains the flexible substrate (FS) in a flat state. The back film (BF) according to one example may include a plastic material, for example, polyethylene terephthalate. When the rigid engraving plate (GS) is formed as part of the carrier glass substrate, the back film (BP) may be laminated on the rear side of the rigid engraving plate (GS) and the rear side of the flexible substrate (FS) from which the carrier glass substrate has been removed. .

The rigid piece plate GS is arranged to coincide with the end of one side of the flexible substrate FS where the pad portion PP is disposed. In particular, the pad portion PP is exposed to the cut surface of the first non-display area IA1 of the flexible substrate FS. One vertical surface of the rigid engraving plate GS is arranged to match the cut surface of the first non-display area IA1 where the pad portion PP is exposed.

A conductive terminal (AP) is disposed on one vertical surface of the rigid piece plate (GS). The conductive terminal AP is in physical/electrical contact with the pads exposed on the cut surface of the first non-display area IA1 of the flexible substrate FS.

The conductive terminal (AP) is electrically connected to the flexible circuit film (TC). The driving integrated circuit 300 is mounted on one side of the flexible circuit film (TC). The flexible circuit film TC can be bent to the back of the flexible substrate FS, and the driving integrated circuit 300 mounted on the flexible circuit film TC can be mounted on the back of the rigid engraving plate GS.

It is preferable that the maximum size of the rigid engraving plate GS does not exceed the size of the first non-display area IA1. Therefore, it is desirable to arrange the rigid engraving plate GS so as not to overlap the display area AA. As a result, the rigid engraving plate GS may partially overlap the barrier film BF and/or the optical film POL that covers a portion of the first non-display area IA1. In some cases, when the rigid plate GS is formed to a minimum size, it may be arranged so as not to overlap the barrier film BF and/or the optical film POL.

As a result, the contact area between the pad portion PP and the flexible circuit film TC in the first non-display area IA1 can be minimized. That is, as shown in FIG. 2, the area of the first non-display area (IA1) can be minimized to the same level as the opposing second non-display area (IA2). According to the present application, the area of all non-display areas arranged on the four sides of the flexible display device can be minimized.

Hereinafter, with further reference to FIG. 3, the connection structure between the pad portion PP and the flexible circuit film TC will be described in detail. Figure 3 is an enlarged perspective view showing a connection structure between a pad portion and a flexible circuit film having a driving integrated circuit in a narrow-bezel flexible electroluminescent display device according to an embodiment of the present application.

A pixel array layer 120 is formed on the flexible substrate FS. In the pixel array layer 120, pixels P, scan lines SL, data lines DL, and pixel driving power lines PL are formed in the display area AA.

The flexible substrate (FS) includes a display area (AA) and a non-display area (IA). FIG. 3 shows an enlarged view of the first non-display area (IA1) where the display area (AA) and the pad portion (PP) are arranged.

Although omitted in the drawing, pixels including a light emitting element and a thin film transistor are arranged in the display area AA. A link wire (LK) and a pad portion (PP) are disposed in the first non-display area (IA1) of the flexible substrate (FS). The link line LK includes a data link line DK extending from the data line DL disposed in the display area AA and a power link line PK extending from the pixel driving power line PL. Data pads DP and pixel driving power pads LP may be alternately arranged in the pad portion PP. Although not shown in the drawing, pads for receiving various power and timing synchronization signals may also be arranged.

The data pad (DP) is disposed at the end of the data link line (DK) extending from the end of the data line (DL) disposed in the display area (AA), and the pixel driving power pad (LP) is disposed in the display area (AA). It is disposed at the end of the power link wire (PK) extending from the end of the pixel driving power wire (LP). The link wiring (DK, PK), data pad (DP), and pixel driving power pad (LP) may be formed simultaneously with the thin film transistor formed in the display area (AA).

The end surfaces of the pads DP and LP formed on the pad portion PP of the flexible substrate FS are exposed to the cross section of the flexible substrate FS. For example, after completing the components including the pixel array layer 120 on the flexible substrate FS, a portion of the flexible substrate FS where unnecessary components are disposed is cut. At this time, when the pads DP and LP are cut across the central portion, the cross section of the pads DP and LP is on one side of the flexible substrate FS, that is, the cross section of the first non-display area IA1. exposed.

A rigid engraving plate GS is bonded to the lower part of the first non-display area IA1 of the flexible substrate FS. Accordingly, the cross section of the first non-display area IA1 where the pads DP and LP are disposed and exposed on the flexible substrate FS forms the same plane as the vertical cross section of one side of the rigid engraving plate GS. For example, after forming the flexible substrate FS on the rigid carrier substrate and completing the display elements on the flexible substrate FS, the flexible substrate is stretched across the central portion of the pads DP and LP in the pad portion PP. By simultaneously cutting the (FS) and the rigid carrier substrate, a cross-sectional structure as shown in FIG. 3 can be obtained.

Looking at the area where the rigid engraving plate GS is disposed, the width W of the rigid engraving plate GS is greater than the width of the minimum pad portion PP and is equal to or smaller than the width of the first non-display area IA1. It is desirable. Therefore, it is preferable that the rigid piece plate GS is disposed corresponding to the link wire LK and the pad portion PP. The length L of the rigid engraving plate GS is preferably longer than the minimum length of the pad portion PP and smaller than the length of the first non-display area IA1. For example, it may have a size that is the same as or slightly larger than the size of the pad portion PP in FIG. 1 .

Conductive terminals (AP) are applied to the cross sections of the flexible substrate (FS) and the rigid plate (GS). In particular, it is preferable that the conductive terminal AP is electrically connected by directly contacting the pads DP and LP exposed on the end surface of the flexible substrate FS. In addition, the conductive terminal AP preferably has the same width as the pads DP and LP and has a length extending from the flexible substrate FS to a portion of the rigid plate GS. As a result, a cross section of one side of the rigid substrate GS has a structure in which a plurality of conductive terminals AP are arranged in one-to-one correspondence with the pads DP and LP.

A plurality of conductive terminals (AP) are. It is connected in one-to-one correspondence with the pad terminal (CPD) placed on the flexible circuit film (TC). Pad terminals (CPD) of the flexible circuit film (TC) are connected to ends of circuit wires (LPD), and the circuit wires (LPD) are connected to the driving integrated circuit 300. For example, output terminals of the driving integrated circuit 300 may be connected to the circuit wiring (LPD). As a result, the output terminals of the driving integrated circuit 300 are electrically connected to the pad terminal (CPD) through the circuit wiring (LPD), and the pads (DP, LP) is electrically connected.

The conductive terminal (AP) and the flexible circuit film (TC) are electrically connected via an anisotropic conductive film (ACF). Anisotropic conductive film is a connecting member in which a plurality of conductive balls with an insulating shell are dispersed inside an organic film. When the conductive terminal (AP) and the pad terminal (CPD) of the flexible circuit film (TC) are bonded with an anisotropic conductive film (ACF) in between, the conductive terminal (AP) and the pad terminal (CPD) are formed among various conductive balls. When the insulating shell of the conductive balls placed between them is broken, the one-to-one corresponding conductive terminal (AP) and pad terminal (CPD) are electrically connected.

Hereinafter, a narrow-bezel flexible electroluminescent display device according to another embodiment of the present application will be described with reference to FIG. 4. Figure 4 is a plan view showing a narrow-bezel flexible electroluminescent display device according to another embodiment of the present application. In the following description, the terms 'back', 'bottom', and 'rear' are the same thing, but are expressed differently for convenience of explanation.

A narrow-bezel flexible electroluminescent display device according to another embodiment of the present application includes a flexible substrate (FS), a rigid plate (GS), a sacrificial layer (SCL), a back film (BP), a conductive terminal (AP), and a flexible substrate (FS). It includes a circuit film (TC), and a driving integrated circuit (300). In FIG. 4 , for convenience, the anisotropic conductive film that may be interposed between the conductive terminal (AP) and the flexible circuit film (TC) is not shown.

The flexible substrate FS includes a plastic material or a glass material as a base layer. The flexible substrate FS according to one example may include an opaque or colored polyimide material. For example, a flexible substrate (FS) made of polyimide may be a cured product of polyimide resin coated to a certain thickness on the entire surface of a release layer provided on a relatively thick carrier substrate. In this case, the carrier glass substrate is separated from the flexible substrate FS by releasing the release layer using a laser release process.

In order to separate the carrier glass substrate from the flexible substrate (FS) using a release process, a sacrificial layer is formed between the carrier glass substrate and the flexible substrate (FS). A sacrificial layer is applied over the entire back side of the flexible substrate (FS). In another embodiment of the present application, the rigid engraving plate GS is formed by leaving an area corresponding to the pad portion PP in the flexible substrate FS without removing the entire carrier glass substrate. In this case, the sacrificial layer (SCL) remains between the rigid plate (GS) and the flexible substrate (FS).

In other manufacturing processes, the flexible substrate (FS) is formed on a rigid substrate without using a sacrificial layer, and after completing the display elements, the rigid substrate and the flexible substrate (FS) can be separated. In this case, as shown in FIG. 2, there may be no sacrificial layer between the rigid plate GS and the flexible substrate FS.

The flexible substrate FS may include a display area AA and a non-display area IA surrounding the display area AA. A pixel array layer 120, an encapsulation layer 130, a barrier film (BF), and an optical film (POL) may be sequentially stacked on the flexible substrate FS.

A rigid plate (GS) is disposed on the bottom of the flexible substrate (FS) with a sacrificial layer (SCL) in between. The rigid engraving plate GS may have a size corresponding to the pad portion PP in the flexible substrate FS. For example, the length of the rigid piece plate GS may be equal to or slightly larger than the length of the pad portion PP. The width of the rigid piece plate GS may be equal to or slightly larger than the width of the pad portion PP, that is, the length of the pad. As another example, the rigid engraving plate GS may have the same size as the first non-display area IA1 where the pad portion PP is disposed.

A back film (BP) may be coupled to the rear surface of the flexible substrate (FS) with respect to the thickness direction (Z) to the flexible substrate (FS) provided with the rigid engraving plate (GS). The back film BP maintains the flexible substrate FS in a flat state. The back film BP according to one example may include a plastic material, for example, polyethylene terephthalate. When the rigid engraving plate (GS) is formed as part of the carrier glass substrate, the back film (BP) may be laminated on the rear side of the rigid engraving plate (GS) and the rear side of the flexible substrate (FS) from which the carrier glass substrate has been removed. .

The rigid piece plate GS is arranged to coincide with the end of one side of the flexible substrate FS where the pad portion PP is disposed. In particular, the pad portion PP is exposed to the cut surface of the first non-display area IA1 of the flexible substrate FS. One vertical surface of the rigid engraving plate GS is arranged to match the cut surface of the first non-display area IA1 where the pad portion PP is exposed.

A conductive terminal (AP) is disposed on one vertical surface of the rigid piece plate (GS). The conductive terminal AP is in physical/electrical contact with the pads exposed on the cut surface of the first non-display area IA1 of the flexible substrate FS.

The conductive terminal (AP) is electrically connected to the flexible circuit film (TC). The driving integrated circuit 300 is mounted on one side of the flexible circuit film (TC). The flexible circuit film TC can be bent to the back of the flexible substrate FS, and the driving integrated circuit 300 mounted on the flexible circuit film TC can be mounted on the back of the rigid engraving plate GS.

As a result, the contact area between the pad portion PP and the flexible circuit film TC in the first non-display area IA1 can be minimized. That is, by minimizing the area of the first non-display area IA1, the area of all non-display areas arranged on the four sides of the flexible display device can be minimized.

Hereinafter, a narrow-bezel flexible electroluminescent display device according to another embodiment of the present application will be described with reference to FIG. 5. Figure 5 is a plan view showing a narrow-bezel flexible electroluminescent display device according to another embodiment of the present application. In FIG. 5 , for convenience, the anisotropic conductive film that may be interposed between the conductive terminal (AP) and the flexible circuit film (TC) is not shown.

A narrow-bezel flexible electroluminescent display device according to another embodiment of the present application includes a flexible substrate (FS), a rigid plate (GS), a back film (BP), a conductive terminal (AP), and a flexible circuit film (TC). , and a driving integrated circuit 300.

The narrow-bezel flexible electroluminescent display device according to another embodiment of the present application shown in FIG. 5 uses a method of separating the rigid glass substrate from the flexible substrate (FS) without using a sacrificial layer. indicated. Therefore, there is no sacrificial layer between the rigid plate (GS) and the flexible substrate (FS). The presence or absence of a sacrificial layer is due to differences depending on the manufacturing process.

The flexible substrate FS includes, as a base layer, a plastic material or a glass material. The flexible substrate FS according to one example may include an opaque or colored polyimide material. For example, a flexible substrate (FS) made of polyimide may be a cured polyimide resin coated to a certain thickness on the front surface of a relatively thick carrier substrate. In this case, the carrier glass substrate is separated from the flexible substrate (FS) using a laser release process.

The flexible substrate FS may include a display area AA and a non-display area IA surrounding the display area AA. A pixel array layer 120, an encapsulation layer 130, a barrier film (BF), and an optical film (POL) may be sequentially stacked on the flexible substrate FS.

The barrier film (BF) is a film laminated on the encapsulation layer 130 and is intended to protect all devices below it. Accordingly, it may have a size that covers not only the entire display area AA but also most of the non-display area IA. For example, as shown in FIG. 5 , the entire upper surface of the flexible substrate FS may be covered except for a portion of the first non-display area IA1 where the pad portion PP is disposed.

An optical film (POL) is laminated on the upper surface of the barrier film (BF) to prevent reflection of external light. The optical film POL may be used to prevent color from being deteriorated when external light is reflected by a metal layer disposed in the display area AA. Therefore, it is desirable to arrange the optical film (POL) so as to completely cover at least the display area (AA). The optical film (POL) may have a slightly smaller size than the barrier film (BF).

A rigid engraving plate (GS) is disposed on the lower surface of the flexible substrate (FS). The rigid engraving plate GS may have a size corresponding to the pad portion PP in the flexible substrate FS. For example, the length of the rigid piece plate GS may be equal to or slightly larger than the length of the pad portion PP. The width of the rigid piece plate GS may be equal to or slightly larger than the width of the pad portion PP, that is, the length of the pad. As another example, the rigid engraving plate GS may have the same size as the first non-display area IA1 where the pad portion PP is disposed.

A back film (BF) may be coupled to the rear surface of the flexible substrate (FS) with respect to the thickness direction (Z) to the flexible substrate (FS) provided with the rigid engraving plate (GS). The back film (BF) maintains the flexible substrate (FS) in a flat state. The back film (BF) according to one example may include a plastic material, for example, polyethylene terephthalate. When the rigid engraving plate (GS) is formed as part of the carrier glass substrate, the back film (BF) may be laminated on the rear side of the rigid engraving plate (GS) and the rear side of the flexible substrate (FS) from which the carrier glass substrate has been removed. .

The back film (BF) is bonded by crossing the step between the back of the flexible substrate (FS) and the back of the rigid plate (GS). In this case, if the step between the back of the flexible substrate FS and the back of the rigid engraving plate GS is too large, the back film BF may be peeled from the step. When the back film (BF) is peeled off, the lower surface of the flexible substrate (FS) is exposed to the air, greatly increasing the possibility that moisture or foreign substances will penetrate into the display device.

In order to prevent this problem, it is necessary that the back film (BF) is completely adhered to the back of the flexible substrate (FS) and the rigid plate (GS). To this end, another embodiment of the present application is characterized in that an inclined side (IF) having a gentle slope is provided on the inner wall of the rigid piece plate (FS). The inclined side IF has a certain angle with the lower surface of the flexible substrate FS. In particular, it is desirable to have an obtuse angle greater than 90 degrees.

The rigid piece plate (GS) according to another embodiment of the present application has a trapezoidal cross-sectional shape, having a vertical side (VF), an inclined side (IF), a horizontal upper surface (UF), and a horizontal lower surface (LF). . The vertical side (VF) refers to a surface disposed on the side wall and extension surface of the pad portion (PP). The inclined side (IF) refers to an inclined surface having a certain angle with the lower surface of the flexible substrate (FS). The horizontal upper surface (UF) is in contact with the lower surface of the flexible substrate (FS) and refers to a plane connecting the vertical side (VF) and the inclined side (IF). The horizontal lower surface (LF) faces the horizontal upper surface (UF) and refers to a plane that is exposed to the outside and connects the vertical side (VF) and the inclined side (IF).

The rigid piece plate GS is arranged to coincide with the end of one side of the flexible substrate FS where the pad portion PP is disposed. In particular, the pad portion PP is exposed to the cut surface of the first non-display area IA1 of the flexible substrate FS. One vertical surface of the rigid engraving plate GS, that is, the vertical side VF, is arranged to form an extended plane with a cut surface of the first non-display area IA1 where the pad portion PP is exposed.

A conductive terminal (AP) is disposed on the vertical side (VF) of the rigid piece plate (GS). The conductive terminal AP is in physical/electrical contact with the cross sections of the pads DP and LP exposed on the cut surface of the first non-display area IA1 of the flexible substrate FS.

The conductive terminal (AP) is electrically connected to the flexible circuit film (TC). The driving integrated circuit 300 is mounted on one side of the flexible circuit film (TC). The flexible circuit film (TC) can be bent to the back of the flexible substrate (FS), and the driving integrated circuit 300 mounted on the flexible circuit film (TC) is located on the lower surface of the rigid plate (GS), that is, the horizontal lower surface (LF). Can be mounted on top.

As a result, the contact area between the pad portion PP and the flexible circuit film TC in the first non-display area IA1 can be minimized. That is, by minimizing the area of the first non-display area IA1, the area of all non-display areas arranged on the four sides of the flexible display device can be minimized.

With further reference to the drawings below, various structures further provided with additional components in the narrow-bezel flexible electroluminescent display device according to the present application will be described. 6A and 6B are diagrams showing a narrow-bezel flexible electroluminescent display device according to an example of the present application. 6A and 6B show a case in which a protection pattern PAT is further included between the link wires LK and/or between the pad terminals in the pad portion PP. In the following description, if there is a description of reference numerals not shown in the drawings, reference is made to the previously described drawings.

Referring to FIGS. 6A and 6B, the narrow-bezel flexible electroluminescent display device according to an example of the present application further includes a protection pattern (PAT) between the link wires (LK) and/or between the pads in the pad portion (PP). It can be included. The protection pattern PAT may be a depression formed by removing insulating films between the link wires LK or between pads of the pad portion PP.

For example, as shown in FIG. 6B, the lower buffer layer BF1 may be first stacked on the flexible substrate FS, and the light-shielding metal layer LS may be formed thereon. An upper buffer layer (BF2) is stacked on the light-shielding metal layer (LS). A gate metal layer (GM) may be formed on the upper buffer layer (BF2). The gate metal layer (GM) may be a metal layer for a gate electrode and scan wiring. A gate insulating film (GI) may be stacked on the gate metal layer (GM).

A semiconductor layer may be formed on the gate insulating layer GI. The semiconductor layer may be formed only in the display area AA, and in this case, the laminated structure may not appear in the pad area PP. A lower insulating layer (IL1) is stacked on the gate insulating layer (GI). An intermediate metal layer (TM) is formed on the lower insulating layer (IL1). An upper insulating layer (IL2) is laminated on the middle metal layer (TM). A source metal layer (SD) may be formed on the upper insulating layer (IL2).

Here, the link wire (LK) and the pad portion (PP) may be formed of the source metal layer (SD). The metal layers stacked below the source metal layer (SD) may be formed in an island shape only on the link wire (LK) and the pad portion (PP). Alternatively, the pad may be formed by being connected to a wire other than the data wire (DL) and the pixel driving power wire (PL). In this case as well, the link wire LK and pad for other wires may be formed in an island shape in the source metal layer SD only in the first non-display area IA1. As another example, only the source metal layer SD remains, and other metal layers TM, G, and LS may not be disposed underneath it.

The protection pattern (PAT) disposed between the link wires (LK) or between the pads of the pad portion (PP) is a lower buffer layer (BF1), an upper buffer layer (BF2), and a gate insulating layer stacked on the flexible substrate (FS). (GI), it may be a depression pattern formed by etching the lower insulating layer (IL1) and upper insulating layer (IL2) together. When the pad portion PP is cut across the pad portion PP so that the cross section of the pad portion PP is exposed to the end of the first non-display area IA1, the insulating layers are cut and a separation phenomenon occurs between the stacked thin films. This can happen. However, if the protection pattern (PAT) is formed first, separation or peeling between thin films can be prevented during the cutting process.

7A and 7B are diagrams showing a narrow-bezel flexible electroluminescent display device according to an example of the present application. 7A and 7B show the stacked structure of the link wire LK. The link wire LK may be formed of a single metal layer, but may also form a multi-layer structure connected with other metal layers stacked underneath it.

Referring to FIGS. 7A and 7B, in the narrow-bezel flexible electroluminescent display device according to an example of the present application, the link wire (LK) has an upper metal layer connected to other metal layers stacked below through a link hole (LH). It has a structure.

For example, as shown in FIG. 7B, the lower buffer layer BF1 may be first stacked on the flexible substrate FS, and the light-shielding metal layer LS may be formed thereon. An upper buffer layer (BF2) is stacked on the light-shielding metal layer (LS). A gate metal layer (GM) may be formed on the upper buffer layer (BF2). The gate metal layer (GM) may be a metal for the gate electrode and scan wiring. A gate insulating film (GI) may be stacked on the gate metal layer (GM).

A semiconductor layer may be formed on the gate insulating layer GI. The semiconductor layer may be formed only in the display area AA, and in this case, the laminated structure may not appear in the pad area PP. A lower insulating layer (IL1) is stacked on the gate insulating layer (GI). An intermediate metal layer (TM) is formed on the lower insulating layer (IL1). An upper insulating layer (IL2) is laminated on the middle metal layer (TM). A source metal layer (SD) may be formed on the upper insulating layer (IL2).

Here, the link wire (LK) and the pad portion (PP) may be formed of the source metal layer (SD). Metal layers stacked below the source metal layer (SD) may have the same pattern as the source metal layer (SD). For example, it may be formed in an island shape only at the link wire (LK) and the pad portion (PP) and connected to the source metal (SD) and the link-hole (LH). In this case, the link-hole (LH) includes the second insulating layer (IL2), the middle metal layer (TM), the first insulating layer (IL1), the gate insulating layer (GI), the gate metal (G), and the upper buffer layer (BF2). It can be formed by continuous etching. A link wire (LK) and a pad are formed using source metal (SD) on the flexible substrate (FS) on which the link hole (LH) is formed. Then, the link wire LK has a structure in which the source metal layer SD is connected to the lower middle metal layer TM, the gate metal layer GM, and the light-shielding metal layer LS through the link-hole LH.

The pad portion PP formed of the source metal SD may further include other pads in addition to the data pad DP connected to the data link line DL. When a pad is formed by being connected to a wire other than the data wire (DL) or the pixel driving power wire (PL), the source metal layer (SD) for other pads is connected to the link wire (LK) and the pad only in the first non-display area ( It can be formed in an island shape in IA1).

In addition, when the pad portion PP is cut across the pad portion PP so that the cross section of the pad portion PP is exposed to the end of the first non-display area IA1, the cut cross section includes the source metal layer SD and the intermediate metal layer. (TM), the tomographic plane of the gate metal layer (GM) and the light-shielding metal layer (LS) is exposed. These exposed metal layers are in contact with conductive terminals (AP). According to an example of the present application, the metal layers exposed in the pad portion PP are not connected only by the conductive terminal AP, but are further connected by the link-hole LH, thereby ensuring good connectivity between the metal layers. It can be secured.

Hereinafter, with reference to FIG. 8, a method of manufacturing a narrow-bezel electroluminescent display device according to the present application will be described. Figure 8 is a flowchart showing a process for manufacturing a narrow-bezel flexible electroluminescent display device according to an example of the present application. In the previous description, the manufacturing method was briefly mentioned in the embodiments of the present application, but hereinafter, it will be described as a specific example.

First, prepare a rigid substrate made of glass or reinforced plastic. (S100) Here, the rigid substrate is preferably a carrier substrate and has a rigidity and thickness suitable for forming devices within process equipment for manufacturing a flexible display device.

A flexible substrate is formed on a rigid substrate. (S200) For example, it can be formed by applying a material with excellent flexibility, such as polyimide.

A display element is formed on a flexible substrate. (S300) The display device may include a buffer layer, a thin film transistor layer formed on the buffer layer, a planarization layer applied on the thin film transistor layer, a light emitting device layer formed on the planarization side, and an encapsulation layer laminated on the light emitting device layer.

The display element layer includes a display area and a non-display area. Scan wiring, data wiring, and driving power wiring are arranged in the display area. Additionally, thin film transistors and light-emitting devices connected to these wirings are disposed. In the non-display area, link wires extending from wires arranged in the display area and pads connected to ends of the link wires are disposed. For example, a data link line extending from the data line and a data pad connected to an end of the data link line may be disposed. Additionally, a driving power link wire extending from the driving power wire and a driving power pad connected to an end of the driving power link wire may be disposed.

In the pad section where the pads are arranged, the flexible substrate and the rigid substrate are cut across the pads based on the center line of the pad section. (S400) As a result, the cross sections of the pads are exposed in the cut cross section.

A portion of the rigid substrate remains on the lower surface of the flexible substrate, and the remainder is separated from the flexible substrate to form a rigid piece plate attached to a portion of the flexible substrate. (S500) Here, it is desirable that the rigid engraving plate remain only in a portion of the non-display area on the lower surface of the flexible substrate. In particular, it is preferable that the rigid engraving plate is arranged to correspond to the pad portion. For example, in the step of cutting based on the center line of the pad part performed previously, the ends of the rigid engraving board and the ends of the flexible board are aligned with each other. A rigid piece plate can be formed in a rectangular shape including both side sides based on the matched ends and an inner end facing the matched ends.

A conductive terminal is formed by applying a low-resistance metal material to the cross section of the pad exposed at the end of the flexible substrate. (S600) It is preferable that the conductive terminal extends a certain distance from the cross section of the pad to the cross section of the rigid plate disposed below. As a result, the conductive terminal has the shape of a pad disposed on the side of the rigid piece plate.

Connect the flexible circuit film to the conductive terminal. (S700) The flexible circuit film is connected to a conductive terminal and serves as a means to transmit various signals necessary to drive the display element layer to the pad portion. Accordingly, a driving integrated circuit for driving the display element layer may be disposed on the flexible circuit film. The flexible circuit film and the conductive terminal may be connected via an anisotropic conductive film.

Although not shown in FIG. 8, the step of forming a sacrificial layer (or release layer) may be further included between the step of preparing the rigid substrate (S100) and the step of forming the flexible substrate (S200). The sacrificial layer may be applied to the entire surface of the rigid substrate, or may be selectively applied only to areas other than those of the rigid engraving plate.

In this case, the step (S500) of separating the rigid substrate to form a rigid engraving plate can be performed by irradiating a laser to the sacrificial layer. When a laser is irradiated to the sacrificial layer, the connection structure bonding the rigid substrate and the flexible substrate may be destroyed, causing the rigid substrate and the flexible substrate to be separated from each other.

It is not necessary to apply a sacrificial layer to separate the rigid substrate from the flexible substrate. A method of separating the rigid substrate and the flexible substrate can also be used without using a sacrificial layer.

Such electric field display devices according to various embodiments of the present application include electronic notebooks, e-books, Portable Multimedia Players (PMPs), navigation, Ultra Mobile PCs (UMPCs), smart phones, mobile communication terminals, mobile phones, Portable electronic devices such as tablet PCs (personal computers), smart watches, watch phones, or wearable devices, as well as televisions, laptops, monitors, refrigerators, microwave ovens, washing machines, cameras, etc. It can be applied to a variety of products.

The features, structures, effects, etc. described in the various embodiments of the present application described above are included in at least one example of the present application and are not necessarily limited to only one example. Furthermore, the features, structures, effects, etc. exemplified in at least one example of the present application can be combined or modified for other examples by those skilled in the art to which the present application pertains. Therefore, contents related to such combinations and modifications should be construed as being included in the scope of the present application.

The present application 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 application belongs that various substitutions, modifications, and changes are possible without departing from the technical details of the present application. It will be clear to those who have the knowledge of. Therefore, the scope of the present application is indicated by the claims described later, and the meaning and scope of the claims and all changes or modified forms derived from the equivalent concept should be interpreted as being included in the scope of the present application.

FS: Flexible substrate T: Thin film transistor
PLN: Flattening layer BN: Bank pattern
DM: dam structure 200: gate driving circuit
120: Pixel array layer 130: Encapsulation layer
ED: Light emitting element AE: Pixel driving electrode
EL: light-emitting layer CE: common electrode
CPL: Common power wiring GS: Rigid piece plate
AP: Conductive terminal TC: Flexible circuit film
BP: Back film BF: Barrier film
POL: optical film 300: driving integrated circuit

Claims (15)

A flexible substrate having a display area and a non-display area surrounding the display area;
a pad portion disposed in a portion of the non-display area;
a rigid sculpture plate bonded to a portion of the lower surface of the flexible substrate;
A pad cross section exposed to a side wall of the pad portion; and
It includes a conductive terminal applied to the cross section of the pad,
The end sides of the rigid piece plate are,
It is disposed in line with the end side of the flexible substrate,
The conductive terminal is in contact with the end surface of the pad and the end side of the rigid piece plate, respectively.
According to claim 1,
a flexible circuit board connected to the conductive terminal; and
A flexible electroluminescent display device further comprising a driving integrated circuit mounted on the flexible circuit board.
According to claim 2,
The flexible circuit board is,
A pad terminal disposed on one short side;
Includes a link wire connected from the pad terminal to the driving integrated circuit,
The pad terminal is connected in one-to-one correspondence with the conductive terminal through an anisotropic conductive film.
According to claim 2,
The flexible circuit board is a flexible electroluminescent display device bent and attached to the bottom surface of the rigid engraving plate.
According to claim 1,
A flexible electroluminescent display device further comprising a back film bonded to a lower surface of the flexible substrate.
According to claim 5,
The back film is,
A flexible electroluminescent display device extending from the lower surface of the flexible substrate and covering the lower surface of the rigid engraving plate.
delete According to claim 1,
Further comprising a dam structure surrounding the display area in the non-display area,
The pad portion is a flexible electroluminescent display device disposed outside the dam structure.
According to claim 8,
In the display area,
scan lines running in a first direction of the flexible substrate;
a data line and a pixel driving power line running in a second direction different from the first direction; and
Defined by the scan wire, the data wire, and the pixel driving power wire, and comprising a plurality of pixels arranged in a matrix manner,
In the non-display area,
a gate driver connected to the scan wire; and
Includes pad terminals connected to the data wire and the pixel driving power wire,
The rigid piece plate,
A flexible electroluminescent display device disposed below the pad terminals.
According to claim 1,
The rigid piece plate,
a vertical side disposed on the sidewall and extension surface of the pad portion;
an inclined side having a certain angle with the lower surface of the flexible substrate; and
A flexible electroluminescent display device having a trapezoidal cross-sectional shape including a horizontal lower surface connecting the vertical side and the inclined side.
Forming a flexible substrate on a rigid substrate;
forming a display element layer having a display area and a non-display area on the flexible substrate; and
forming a rigid engraving plate by leaving a part of the rigid substrate in a portion of the non-display area on the lower surface of the flexible substrate and removing the remainder of the rigid substrate;
The end sides of the rigid piece plate are,
Forming the rigid piece plate to be aligned with the end side of the flexible substrate,
The step of forming the display element layer is,
Forming a wire disposed in the display area, a link wire disposed in the non-display area and extending from the wire, and a pad connected to an end of the link wire,
Cutting the flexible substrate and the rigid substrate across the center of the pad to expose a cross section of the pad,
Further comprising applying a conductive terminal to the cross section of the pad,
The conductive terminal is in contact with an end surface of the pad and an end side of the rigid piece plate, respectively.
delete According to claim 11,
Before forming the flexible substrate, further comprising applying a sacrificial layer on the rigid substrate,
In the step of forming the rigid engraving plate, a laser is irradiated to the sacrificial layer applied to the remainder of the rigid substrate to separate the remainder of the rigid substrate from the flexible substrate.
delete According to claim 11,
A method of manufacturing a flexible electroluminescent display device further comprising connecting a flexible circuit board to the conductive terminal.