KR20210081143A - Organic light emitting diode display and manufacturing method of the same - Google Patents

Abstract

The present invention provides an organic light emitting display device capable of minimizing defects in which an organic light emitting layer is peeled off by a laser in a process of manufacturing the organic light emitting display device using a flexible substrate, and a method for manufacturing the same. When an organic light emitting display device is manufactured using a polyimide-based plastic substrate, a sacrificial layer is disposed on the manufacturing substrate and the substrate is disposed using a curable polyimide solution. The substrate includes a light absorption layer. After irradiating a laser on the back surface of the manufacturing substrate in the form of a line beam to weaken the intermolecular bonding force of a material such as amorphous silicon constituting the sacrificial layer or to generate a gas, the bonding strength with the manufacturing substrate is weakened, the manufacturing substrate is removed. In such a method, in addition to releasing the bonding force of the sacrificial layer, the laser used in the process for removing the manufacturing substrate minimizes the effect on the organic light emitting layer or the like by the light absorbing layer, so provided is an organic light emitting display device capable of minimizing defects in which an organic light emitting layer is peeled off in a flexible environment.

Description

Organic light emitting display device and manufacturing method thereof {ORGANIC LIGHT EMITTING DIODE DISPLAY AND MANUFACTURING METHOD OF THE SAME}

The present invention relates to an organic light emitting display device and a method for manufacturing the same, and more particularly, in an organic light emitting display device to which a flexible substrate is applied. An object of the present invention is to provide an organic light emitting display device capable of minimizing a defect in which a light emitting layer is peeled off and a manufacturing method thereof.

Recently, as society enters the information age in earnest, interest in information displays that process and display a large amount of information is on the rise, and as the demand for using portable information media increases, various lightweight and thin flat panel display devices have been developed and are in the spotlight.

Among various flat panel display devices, organic light emitting diodes (OLEDs) are display devices that use self-luminous devices as display devices, and are required for liquid crystal display devices (LCDs), which are non-light emitting devices. Because it does not require a backlight (Back Light), it is possible to be lightweight and thin.

In addition, the viewing angle and contrast ratio are excellent compared to the liquid crystal display device, and it is advantageous in terms of power consumption, direct current low voltage driving is possible, the response speed is fast, and the internal component is solid, so it is strong against external shock, and the temperature range is wide. It has advantages.

In particular, since OLED is formed using an organic thin film, interest is being focused on it as an optimal material that can be applied to a flexible display device using the flexibility and elasticity that are characteristics of an organic thin film.

In response to these advantages, curved, rollable, and foldable display devices are being actively developed in recent years, and research on organic light emitting display devices including OLEDs to implement such display devices Activities are being actively carried out.

In order to implement such an organic light emitting display device, a flexible material such as plastic or a metal foil is used as a substrate. In general, polyimide is widely used as a substrate of the organic light emitting display device.

On the other hand, such a polyimide (Polyimide) has heat resistance enough to withstand the manufacturing process of an organic light emitting display device, but has a disadvantage of large hygroscopicity. In this case, the device performance of the switching and driving thin film transistors deteriorates, which in turn lowers the reliability of the OLED.

In order to minimize this, in an organic light emitting display device using polyimide as a substrate, a hydrophobic material may be included as an intermediate layer or a plasma-treated functional layer for blocking moisture permeation may be included.

A dielectric layer may be added as an intermediate layer in the middle of the polyimide substrate because the substrate made of a plastic-based material such as polyimide may cause charging. However, when the dielectric layer is used as an intermediate layer, delamination may occur due to an external force such as bending or folding, which in turn may deteriorate the reliability of the flexible organic light emitting diode display.

On the other hand, a substrate made of a flexible material such as polyimide can be manufactured by applying a curable polyimide solution on a manufacturing substrate such as glass and then curing the polyimide substrate. After the curing process, the substrate is removed from the above-mentioned manufacturing substrate. steps should be performed.

The hardened substrate on the manufacturing substrate may require a relatively large external force to separate it from the manufacturing substrate, and the substrate peeling process by this external force may damage the driving device, various wirings, and organic light emitting devices disposed on the substrate. There is a limit to the substrate peeling process by the

In order to peel the substrate from the manufacturing substrate, a sacrificial layer that can lower bonding strength under certain conditions is applied on the manufacturing substrate, and then a curable polyimide solution is applied and cured to form a substrate. After disposing the wiring and the organic light emitting device, a process in which the bonding strength of the above-described sacrificial layer may be reduced (for example, by irradiating a laser to change the molecular structure of the sacrificial layer or to generate gas from the sacrificial layer) When this is performed, the substrate can be easily separated from the manufacturing substrate without the need to apply a large external force.

However, since the process of causing a change in state of the sacrificial layer by applying laser or heat may also cause a change in state in the organic light emitting layer in the organic light emitting device disposed on the substrate, the organic light emitting layer in the organic light emitting device in the process of applying laser or heat There is a problem that delamination, damage, or optical properties may be changed.

As described above, in the process of manufacturing the organic light emitting display device to which the flexible substrate is applied, there is a problem in that the organic light emitting device or the driving device may be damaged in the process of separating the flexible substrate from the manufacturing substrate. Accordingly, the inventors of the present invention have invented an organic light emitting display device capable of protecting an organic light emitting layer and a driving device from laser and heat in the process of separating the substrate from the manufacturing substrate, and a method for manufacturing the same.

An object to be solved according to an exemplary embodiment of the present specification is an organic light emitting display device in which damage or a change in characteristics that may be caused to an organic light emitting layer and a driving device by a laser that may be applied in the process of manufacturing the organic light emitting display device or a change in characteristics is minimized, and manufacturing the same to provide a way

In the flexible display device as described above, a substrate is formed of a material such as polyimide on the manufacturing substrate, and then a laser is used to separate the manufacturing substrate and the substrate, and the effect thereof, and the change in the state of the organic light emitting layer described above and to provide an organic light emitting display device capable of improving reliability as a flexible organic light emitting display device by minimizing peeling of the organic light emitting layer in a flexible environment due to a change in interlayer adhesion, and a method for manufacturing the same.

The problems to be solved according to an embodiment of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

According to an embodiment of the present specification, there is provided a foldable or bendable organic light emitting display device having an organic light emitting device on a substrate. The substrate includes a first substrate, a light absorption layer, and a second substrate, a light absorption layer is disposed on the first substrate, and a second substrate is disposed on the light absorption layer. The driving element and the organic light emitting element are disposed on the second substrate together with the insulating layer, the flattening layer, the bank layer, and the like. The substrate is disposed in the order of the first substrate, the light absorption layer, and the second substrate from the bottom, and may be made of a plastic-based material, and may be a transparent and flexible substrate.

A method of manufacturing an organic light emitting display device according to an embodiment of the present specification is provided. In order to manufacture a flexible or foldable organic light emitting display device, a sacrificial layer is disposed on the manufacturing substrate to manufacture a polyimide-based plastic substrate, and a curable polyimide solution is applied to arrange the first substrate. After disposing the light absorbing layer on the first substrate, a second substrate is disposed by applying a curable pyrimide solution again to form a substrate supporting the components of the organic light emitting diode display. Thereafter, a barrier layer, an organic insulating film, a planarization layer, etc. made of an organic or inorganic material are disposed on the second substrate, and an organic light emitting device including a driving device and an organic light emitting layer connected to the driving device is disposed. Thereafter, by irradiating a laser on the back surface of the manufacturing substrate in the form of a line beam to weaken the intermolecular bonding force of a material such as amorphous silicon constituting the sacrificial layer or to generate a gas, the bonding force between the manufacturing substrate and the first substrate After weakening, remove the manufacturing substrate. In this way, in addition to releasing the bonding force of the sacrificial layer, the laser used in the process for removing the manufacturing substrate is minimized by the light absorbing layer that the organic light emitting layer is peeled off in a flexible environment. It is possible to provide a method for manufacturing a minimized organic light emitting diode display.

By providing a light absorbing layer according to an embodiment of the present specification, the effect of the laser on other components other than the sacrificial layer in the process of removing the manufacturing substrate using a laser can be minimized, and thus the peeling phenomenon can be prevented even in a flexible environment. There is a minimization effect.

In addition, in the process of weakening the bonding force of the sacrificial layer using a laser by providing a light absorbing layer according to another embodiment of the present invention, the process range for laser intensity, etc. is widely utilized to secure process stability and reduce manufacturing costs There is an effect you can do.

The effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

Since the content of the invention described in the problems to be solved above, the means for solving the problems, and the effects do not specify the essential characteristics of the claims, the scope of the claims is not limited by the matters described in the content of the invention.

1 is a schematic plan view of an organic light emitting diode display according to an exemplary embodiment of the present specification.
FIG. 2 is a schematic cross-sectional view taken along line II of FIG. 1 .
3A to 3B are schematic perspective views for explaining a method of separating a manufacturing substrate according to an embodiment of the present specification.
4 is a schematic cross-sectional view for explaining the configuration of a light absorption layer according to an embodiment of the present specification.
5 is a flowchart illustrating a method of manufacturing an organic light emitting diode display having a light absorption layer according to an exemplary embodiment of the present specification.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims.

The shapes, sizes, proportions, angles, numbers, etc. disclosed in the drawings for explaining the embodiments of the present invention are exemplary, and thus the present invention is not limited to the illustrated matters. Like reference numerals refer to like elements throughout. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, 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, when a temporal relationship is described as 'after', 'following', 'after', 'before', etc., 'immediately' or 'directly' Unless ' is used, cases that are not continuous may be included.

Although the first, second, etc. are used to describe various components, these components 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 invention.

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

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic plan view of an organic light emitting display device according to an exemplary embodiment of the present specification.

As shown, the organic light emitting diode display 100 is connected to a thin film transistor (DTr, see FIG. 2 ) and a thin film transistor (DTr, see FIG. 2 ) on a substrate 110 to drive a light emitting diode (E, FIG. 2 ). see) is formed. When the organic light emitting diode display 100 is a flexible display device or a foldable display device, a flexible material may be used for the substrate 100 , and may be a transparent flexible substrate.

In more detail, on the substrate 110 , an active area A/A in the center and a non-display area N/A are defined along the edges of the active area A/A, and the active area A/A is The area in which the light emitting diode E (refer to FIG. 2 ) is disposed, refers to an area in which an image is substantially displayed, and may be referred to as a display area.

In the active region A/A, a plurality of gate lines GL and data lines DL intersect each other to define a plurality of pixel regions P, and each pixel region P has a light emitting diode E, FIG. 2) connected to a thin film transistor (DTr, see FIG. 2) is disposed, the thin film transistor (DTr, see FIG. 2) operates in association with a driving unit (not shown) located outside, and a light emitting diode (E, FIG. 2) reference) to control the amount of driving current provided to

Here, the non-display area N/A surrounding the edge of the active area A/A includes a pad part PAD in which the pad 130 is positioned at the upper end of the active area A/A, the pad ( 130 is connected to a circuit film (not shown) such as an FPCB, and functions as a contact terminal connecting the circuit film (not shown) and the wiring 131 to each other.

That is, a printed circuit board (not shown) connected through a circuit film (not shown) such as a flexible printed circuit board (FPCB) may be connected to the pad part PAD, and a thin film transistor (DTr) is formed on the printed circuit board (not shown). , a data driver and a gate driver that provide a driving signal to (see FIG. 2 ) may be mounted.

Alternatively, it may be disposed on a circuit film (not shown) in a manner such as chip-on-film (COF), tape-carrier-package (TCP), or the like, and may be connected to the pad part PAD of the substrate 110 .

A plurality of wires 131 are positioned between the pad 130 and the active area A/A, and the wires 131 transmit various electrical signals transmitted through the pad 130 to the active area A/A. It is transmitted to the arranged thin film transistor (DTr, see FIG. 2).

In addition, the ground wiring GND is disposed around the active region A/A, and a ground voltage applied from the outside is supplied to the ground wiring GND.

Although the following drawings will be described, in the organic light emitting diode display 100 according to the embodiment of the present invention, the substrate 110 may be made of multi-layered polyimide, and during the manufacturing process, the manufacturing substrate and the substrate In order to minimize the influence that may occur in the process of separating the 110 , the substrate 110 includes the light absorption layer 120 to minimize defects that may occur during the separation process from the manufacturing substrate described above.

In particular, since the substrate 110 further includes the light absorption layer 120, even when a laser is irradiated through the rear surface of the substrate 110, it is possible to minimize defects in which characteristics of the organic light emitting device and the thin film transistor are changed by the laser, Reliability and lifespan of the organic light emitting diode display 100 may also be prevented from being deteriorated.

This will be described in more detail with reference to FIG. 2 .

FIG. 2 is a schematic cross-sectional view taken along line I-I of FIG. 1 .

Prior to the description, the flexible OLED 100 according to an embodiment of the present invention is divided into a top emission type and a bottom emission type according to the transmission direction of the emitted light. Hereinafter, in the present invention, the upper The light emitting method will be described as an example.

As shown, an active area A/A and a non-display area N/A may be defined in the substrate 110, and the non-display area N/A is one side of the active area A/A. can be located in

A plurality of pixel areas P are disposed in the active area A/A to display an image in the organic light emitting diode display 100 , and the non-display area N/A is other than the active area A/A. As a region of , various circuits, wirings, etc. for driving the pixel region P are disposed.

Here, for convenience of explanation, a region in which the thin film transistor DTr of each pixel region P of the active region A/A is positioned is defined as a region in which the switching region TrA and the storage capacitors C1, C2, and C3 are positioned. The area is defined as the storage area StgA, and the area in which the pad 130 of the non-display area N/A is located is divided into the pad area PAD.

The multi-buffer layer 102 is coated on the substrate 110, and the multi-buffer layer 102 is a buffer layer in which a plurality of thin films are sequentially stacked, for example, silicon nitride (SiNx) and silicon oxide (SiOx). These may be alternately stacked. Alternatively, an organic film and an inorganic film may be repeatedly laminated alternately.

The multi-buffer layer 102 serves to delay diffusion of moisture and/or oxygen penetrating into the substrate 110 .

The active buffer layer 103 may be further positioned on the multi-buffer layer 102 , and the active buffer layer 103 is for protecting the active layer 105 of the thin film transistor DTr, and is introduced from the substrate 110 . It performs the function of blocking various kinds of faults. The active buffer layer 103 may be made of the same material as the multi-buffer layer 102 , and may be formed of amorphous silicon (a-Si) or the like.

A thin film transistor DTr is located in the switching region TrA above the active buffer layer 103 . The thin film transistor DTr according to an embodiment of the present invention is a thin film transistor using a polysilicon material as the active layer 105 and is a low temperature LTPS thin film transistor using polysilicon (Low Temperature Poly-Silicon; LTPS) is used.

Polysilicon materials have high mobility, low energy consumption, and excellent reliability.

That is, the active layer 105 is disposed in the switching region TrA on the active buffer layer 103 . The active layer 105 of the LTPS thin film transistor (hereinafter referred to as thin film transistor, DTr) is a channel region 105a in which a channel is formed when the thin film transistor 105 is driven, and a source region 105b on both sides of the channel region 105a. and a drain region 105c.

The channel region 105a, the source region 105b, and the drain region 105c are defined by ion doping (impurity doping).

At this time, an active pattern 151 is formed in the storage region StgA, which, like the active layer 105, is made of amorphous silicon and is doped with impurities.

Then, the gate insulating layer 106 is disposed on the active layer 105 and the active pattern 151, the gate insulating layer 106 is composed of a single layer of silicon nitride (SiNx) or silicon oxide (SiOx), It may be composed of a multilayer made of silicon nitride (SiNx) and silicon oxide (SiOx).

The gate electrode 107 is positioned so as to overlap the channel region 105a of the active layer 105 on the gate insulating layer 106 corresponding to the switching region TrA. Although not shown in the drawing, the gate wiring extends in one direction. (GL in Fig. 1) is formed.

In addition, in the storage region StgA, the first metal pattern 153 is disposed on the gate insulating layer 106 to correspond to the active pattern 151 .

The gate electrode 107 and the gate wiring (GL in FIG. 1) and the first metal pattern 153 may be made of the same material, and the gate electrode 107 and the gate wiring (GL in FIG. 1) and the first metal pattern ( 153) may have a single-layer structure made of any one of aluminum (Al), aluminum alloy (AlNd), copper (Cu), copper alloy, molybdenum (Mo), and molybdenum (MoTi) having low resistance characteristics, or It may have a double-layer or triple-layer structure by being made of two or more.

Next, a first interlayer insulating layer 108 is disposed over the gate electrode 107 and the gate wiring (GL of FIG. 1 ) and the first metal pattern 153 . The first interlayer insulating layer 108 is formed of silicon nitride (SiNx). ), so that hydrogen contained in the first interlayer insulating film 108 made of silicon nitride (SiNx) diffuses into the active layer 105 during the hydrogenation process for stabilizing the active layer 105 . .

In addition, in the storage area StgA, the second metal pattern 155 is disposed on the first interlayer insulating layer 108 to correspond to the first metal pattern 153 . The second metal pattern 155 may be formed of at least one of aluminum (Al), copper (Cu), molybdenum (Mo), chromium (Cr), nickel (Ni), tungsten (W), or an alloy thereof, and a single layer. Or it may be a multi-layer structure.

A second interlayer insulating layer 109 is positioned on the first interlayer insulating layer 108 and the second metal pattern 155 . The second interlayer insulating layer 109 is formed on the entire surface of the substrate 101 , and is formed of silicon oxide (SiOx). ) can be made.

The gate insulating layer 106 and the first and second interlayer insulating layers 108 and 109 have first and second contact holes exposing the source region 105b and the drain region 105c of the active layer 105, respectively. 111a and 111b and a third contact hole 156 exposing a portion of the first metal pattern 153 of the storage area StgA are provided.

A source electrode 113 and a drain electrode 115 are disposed corresponding to the switching region TrA on the first and second interlayer insulating layers 108 and 109, and the source electrode 113 and the drain electrode 115 are The source region 105b and the active layer 105 respectively through the first and second contact holes 111a and 111b formed in the gate insulating layer 106 and the first and second interlayer insulating layers 108 and 109, respectively. It is connected to the drain region 105c.

The source electrode 113 and the drain electrode 115 also have the same low resistance characteristics as aluminum (Al), aluminum alloy (AlNd), copper (Cu), copper alloy, molybdenum (Mo), molybdenum (MoTi), chromium (Cr) ), titanium (Ti), any one or two or more materials.

In addition, although not shown in the drawing, a data line (DL of FIG. 1 ) intersecting the gate line (GL of FIG. 1 ) and defining the pixel region P is also formed.

At this time, the active layer 105 including the source electrode 113 and the drain electrode 115 and the source and drain regions 105b and 105c in contact with the electrodes 113 and 115 and the active layer 105 are positioned on the upper portion of the active layer 105 . The gate insulating film 106 and the gate electrode 107 constitute a driving thin film transistor (DTr).

Meanwhile, although not shown in the drawings, a switching thin film transistor (not shown) is connected to the driving thin film transistor DTr, and the switching thin film transistor (not shown) has the same structure as the driving thin film transistor DTr.

In addition, the switching thin film transistor (not shown) and the driving thin film transistor (DTr) are shown as an example of a top gate type in which the active layer 105 is made of a polysilicon semiconductor layer in the drawing, but the active layer 105 is an oxide semiconductor layer. Alternatively, it may be provided as a bottom gate type made of pure and impurity amorphous silicon.

In addition, a bottom shield metal (104) may be positioned between the active buffer layer 103 and the multi-buffer layer 102 under the active layer 105, and the lower protective metal 104 is a molybdenum (Mo) material. can be formed using

The lower protective metal 104 serves to suppress variations in device characteristics such as the threshold voltage of the driving thin film transistor DTr from moisture introduced from the outside. Accordingly, the lower protective metal 104 can prevent the occurrence of stains, afterimages, etc. due to luminance imbalance between the pixel regions P.

In addition, the lower protective metal 104 may minimize physical damage to the thin film transistor DTr in the process of forming the substrate 110 of the flexible organic light emitting diode display 100 .

In this case, the lower protective metal 104 may be electrically connected to one of the source electrode 113 and the drain electrode 115 . Through this, the potential of the lower protective metal 104 is increased in the flexible organic light emitting diode display 100 . It can be prevented from being changed during operation or from affecting the threshold voltage Vth of the thin film transistor DTr.

That is, if the lower protective metal 104 is in a floating state, the shift amount of the threshold voltage of the thin film transistors DTr positioned in each pixel region P may be varied, which is a visual defect caused by an unintended change in luminance. will cause

In the present invention, the lower protective metal 104 is connected to the drain electrode 115 as an example. When the lower protective metal 104 and the drain electrode 115 are connected to each other in this way, the lower protective metal 104 is ) and the drain electrode 115 to form an equipotential.

Therefore, if the voltage difference between the lower protective metal 104 and the drain electrode 115 is smaller than the voltage difference between the gate electrode 107 and the source electrode 113 of the thin film transistor DTr, the lower protective metal 104 is The influence on the threshold voltage of the thin film transistor (DTr) by the DTr can be minimized.

In addition, in the storage area StgA, a third metal pattern 157 is positioned on the second interlayer insulating layer 109 to correspond to the second metal pattern 155 , and the third metal pattern 157 is a gate It is connected to the first metal pattern 153 through the third contact hole 156 formed in the insulating layer 106 and the first and second interlayer insulating layers 108 and 109 .

Here, the first metal pattern 153 serves as the second electrode (or upper electrode) of the first storage capacitor C1 and simultaneously becomes the first electrode (or lower electrode) of the second storage capacitor C2, and also serves as the first electrode (or lower electrode) of the second storage capacitor C2. The second metal pattern 155 becomes the second electrode (or upper electrode) of the second storage capacitor C2 and the first electrode (or the lower electrode) of the third storage capacitor C3 .

That is, the active pattern 151 and the first metal pattern 153 and the gate insulating layer 106 positioned between the active pattern 151 and the first metal pattern 153 form the first storage capacitor C1, In addition, the first interlayer insulating layer 108 positioned between the first metal pattern 153 and the second metal pattern 155 and the first metal pattern 153 and the second metal pattern 155 is formed by the second storage capacitor C2 . ) is achieved. In addition, the second interlayer insulating layer 109 positioned between the second metal pattern 155 and the third metal pattern 157 and the second metal pattern 155 and the third metal pattern 157 is a third storage capacitor C3. ) is achieved.

In addition, the protective layer 117 having a drain contact hole 118 exposing the drain electrode 115 of the driving thin film transistor DTr over the source electrode 113 and the drain electrode 115 and the third metal pattern 157 . ) is located.

The protective layer 117 may be made of the same material as the gate insulating layer 106 or the first and second interlayer insulating layers 108 and 109 , or may be made of an organic insulating material for planarization of the flexible substrate 101 . have.

For example, the protective layer 117 may include acrylic resin (polyacrylates resin), epoxy resin (epoxy resin), phenolic resin (phenolicresin), polyamides resin (polyamides resin), polyimide-based resin (polyimides resin), unsaturated polyester It may be formed of at least one of unsaturated polyesters resin, poly-phenyleneethers resin, polyphenylenesulfides resin, and benzocyclobutene, but is not limited thereto. . The protective layer 117 may be formed as a single layer or may be configured as a double or multiple layer.

The protective layer 117 may be formed to a thickness of 2 μm to 5 μm to sufficiently cover the step difference on the substrate 110 .

Meanwhile, the passivation layer 117 is applied to cover all of the active regions A/A, and it is preferable that the passivation layer 117 not cover all of the second interlayer insulating layer 109 positioned below.

This is because the protective layer 117, which may be made of an organic layer, is vulnerable to moisture and air introduced from the outside, so that the protective layer 117 is not exposed to the outside of the flexible organic light emitting diode display 100, and thus This is to prevent moisture and air from flowing into the flexible organic light emitting display device 100 through the protective layer 117 made of an organic layer.

In addition, the dam 140 may be disposed outside the protective layer 117 , and the dam 140 is disposed to completely surround the active area A/A. In the dam 140 , the organic protective film 123b of the protective film 123 for protecting the elements of the flexible organic light emitting display 100 from externally penetrating particles (moisture or air) is formed in the dam 140 ) It functions to limit it to be stably located in the inner area.

The dam 140 may be formed by stacking a protective layer 117 , a bank 119 , and/or a spacer 121 .

In this case, the wirings 131 disposed on the non-display area N/A are provided to connect to the pad 130 of the pad area PAD, and the wirings 131 may be formed of a metal having excellent conductivity. . For example, the wiring 131 may be formed of the same metal as the source electrode 113 or the drain electrode 115 of the thin film transistor DTr.

However, the present invention is not limited thereto, and the wiring 131 may be formed of the same metal as the gate electrode 107 of the thin film transistor DTr.

The pad 130 of the pad region PAD to which the wiring 131 is connected includes the first pad 133 formed of the same metal as the gate electrode 107 and the same metal as the source electrode 113 or the drain electrode 115 . and a second pad 135 formed of

In this case, a fourth contact hole 136 exposing the first pad 133 is provided in the first and second interlayer insulating layers 108 and 109 , and the first pad 133 is passed through the fourth contact hole 136 . ) and the second pad 135 come into contact with each other.

At this time, the active buffer layer 103 and the multi-buffer layer 102 are disposed under the first pad 133 and receive the first pad 133 and the second pad ( 135) is desirable.

In addition, an anode electrode 211 connected to the drain electrode 115 of the driving thin film transistor DTr to form an anode of the light emitting diode E is positioned on the protective layer 117 .

The anode electrode 211 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 an APC alloy (Ag/Pd/ Cu), and a metal material having a high reflectance such as an APC alloy and a stacked structure of ITO (ITO/APC/ITO).

The anode electrode 211 is positioned for each pixel region P, and a bank 119 is positioned between the anode electrodes 211 positioned for each pixel region P. That is, the anode electrode 211 has a structure separated for each pixel area P by using the bank 119 as a boundary for each pixel area P.

A spacer 121 may be disposed on the bank layer 119 . The spacer 121 is disposed to surround the bank layer 119 , and serves to protect the organic light emitting layer 213 of the light emitting diode E from external pressure. will do

The spacer 121 may be formed of the same resin composition as the bank layer 119 , and may be formed of a black spacer having a high light absorption rate to prevent color mixing of light emitted from each pixel region P.

In addition, the organic light emitting layer 213 is positioned on the anode electrode 211 . The organic light emitting layer 213 is a common layer commonly formed in the pixel regions P, and may be a white light emitting layer that emits white light.

In this case, the organic light emitting layer 213 may be formed in a tandem structure of two or more stacks. Each of the stacks may include a hole transporting layer, at least one light emitting layer, and an electron transporting layer. In addition, a charge generation layer may be formed between the stacks. The charge generation layer is formed on the n-type charge generation layer and the n-type charge generation layer adjacent to the lower stack and is located adjacent to the upper stack. A charge generating layer may be included.

The n-type charge generation layer injects electrons into the lower stack, and the p-type charge generation layer injects holes into the upper stack. The n-type charge generating layer may be an organic layer in which an alkali metal such as Li, Na, K, or Cs, or an alkaline earth metal such as Mg, Sr, Ba, or Ra is doped into an organic host material having electron transport ability, The p-type charge generating layer may be doped with a dopant in an organic host material having hole transport ability.

A cathode electrode 215 is positioned on the entire surface of the organic light emitting layer 213, and the cathode 215 may also be formed of a common layer formed in common in the pixel regions P, like the organic light emitting layer 213. and a transparent metal material (TCO, Transparent Conductive Material) such as ITO or IZO that can transmit light, or a semi-conductive material such as magnesium (Mg), silver (Ag), or an alloy of magnesium (Mg) and silver (Ag). It may be formed of a semitransmissive conductive material.

When the cathode electrode 215 is formed of a transflective metal material, light output efficiency may be increased by the micro cavity.

A capping layer may be further formed on the cathode electrode 215 .

In the light emitting diode E, when a predetermined voltage is applied to the anode electrode 211 and the cathode electrode 215 according to a selected signal, holes injected from the anode electrode 211 and electrons provided from the cathode electrode 215 are induced. It is transported to the emission layer 213 to form excitons, and when these excitons are transitioned from an excited state to a ground state, light is generated and emitted to the outside.

At this time, the emitted light passes through the transparent cathode electrode 215 and goes out, and through this, the flexible organic light emitting diode display 100 finally realizes an arbitrary image.

Then, a protective film 123 in the form of a thin film is placed on the driving thin film transistor DTr and the light emitting diode E, and then the protective film 123 and the substrate 110 are bonded to each other, thereby providing a flexible organic light emitting display. Device 100 is encapsulated.

Here, the protective film 123 is used by laminating at least two inorganic protective films 123a and 123c in order to prevent external oxygen and moisture from penetrating into the flexible organic light emitting display device 100 . An organic protective film 123b for supplementing the impact resistance of the inorganic protective films 123a and 123c is preferably interposed between the long inorganic protective films 123a and 123c.

Accordingly, the flexible organic light emitting display device 100 may prevent moisture and oxygen from penetrating into the flexible organic light emitting display device 100 from the outside.

In addition, in the flexible organic light emitting display device 100 according to an embodiment of the present invention, a polarizing plate 160 for preventing a decrease in contrast due to external light may be positioned above the protective film 123 through which light is transmitted. That is, in the flexible organic light emitting display device 100, the polarizing plate 160 that blocks external light incident from the outside is placed in the transmission direction of the light emitted through the organic light emitting layer 213 in the driving mode for realizing an image. contrast will be improved.

Here, the flexible organic light emitting diode display 100 according to the embodiment of the present invention is made of a thin thin film film so that the substrate 110 has flexibility, and includes first and second thin film layers 110a and 110b; and a light absorption layer 120 positioned between the first and second thin film layers 110a and 110b.

The first and second thin film layers 110a and 110b are made of polyimide, and polyimide (PI) is a polymer having a relatively low crystallinity or mostly amorphous structure, and is easily synthesized to form a thin film film. In addition to the advantage of not requiring a crosslinking group for curing, it has excellent heat and chemical resistance, excellent mechanical properties, electrical properties and dimensional stability due to transparency and a rigid chain structure.

However, these polyimides have high hygroscopicity with a water vapor transmission rate (WVTR) of several to several tens of g/m224hr.

Accordingly, when the first and second thin film layers 110a and 110b are formed of polyimide, a large amount of moisture (H 2 O) flows in from the outside through the substrate 110 . At this time, H+ and OH- ions of H2O are diffused toward the switching and driving thin film transistor (not shown, DTr). Threshold voltage and the like are affected on the driving, and accordingly, the device performance of the switching and driving thin film transistors (not shown, DTr) is deteriorated.

Here, both the multi-buffer layer 102 and the active buffer layer 103 have a WVTR of several X 10 g/m224 hr, which is not effective in preventing the diffusion of H + and OH- ions of H 2 O. Therefore, switching and driving thin film transistors (not shown, DTr), more precisely, the lower protective metal 104 is further formed under the active layer 105 to block H + and OH- ions of moisture and/or H 2 O.

However, since the lower protective metal 104 is formed by patterning only the lower portion of the active layer 105 as it is made of a metal material, H+ and OH- ions of H2O are accumulated in the region where the lower protective metal 104 is not present. As a result, deterioration of the switching and driving thin film transistors (not shown, DTr) is caused.

Accordingly, in the flexible organic light emitting diode display 100 according to the embodiment of the present invention, the substrate 110 is divided into first and second thin film layers 110a and 110b, and the first and second thin film layers 110a and 110b are formed. The light absorption layer 120 is further formed therebetween.

The light absorption layer 120 includes an inorganic insulating material such as silicon nitride (SiNx) and silicon oxide (SiOx), and has a WVTR smaller than that of polyimide forming the first and second thin film layers 110a and 110b. (about 1/ 1000 or less)

Through this, it is possible to prevent moisture and oxygen from penetrating into the flexible organic light emitting display device 100 , thereby further improving the reliability of the flexible organic light emitting display device 100 .

Looking at this in more detail, two or more flexible organic light emitting display devices 100 are manufactured together using a large substrate in order to improve a process yield when manufacturing the flexible organic light emitting display device 100 , and then, two or more flexible organic light emitting display devices 100 are manufactured together. It includes a process of individually separating the organic light emitting display device 100 .

Here, in the process of individually separating the two or more flexible organic light emitting display devices 100 manufactured together on a large substrate, it is common to use a cutting means such as a cutting knife and a cutting laser, that is, the two or more flexible organic light emitting diodes using the cutting means. By removing the scribing region, which is a spaced portion between the organic light emitting display devices 100 , the two or more flexible organic light emitting display devices 100 are individually separated.

In the process of manufacturing the organic light emitting display device 100 as described above, the substrate 110 is manufactured using a curable material such as polyimide, which is a flexible material. For this purpose, polyimide is formed on a manufacturing substrate (not shown). After coating and curing, the substrate 110 is manufactured, and then the substrate 110 and the manufacturing substrate (not shown) are separated.

The separation process between the substrate 110 and the manufacturing substrate will be described later, but since the substrate 110 includes the light absorbing layer 120, defects due to the influence of a laser, etc. used in the separation process from the manufacturing substrate can be minimized. .

As described above, in the flexible organic light emitting diode display 100 according to the embodiment of the present invention, the flexible substrate 110 includes first and second thin film layers 110a and 110b made of polyimide, and first and second thin film layers 110a and 110b. By forming the light absorption layer 120 between the two thin film layers 110a and 110b, in the process of separating the substrate 110 from the manufacturing substrate, the influence of the organic light emitting layer or the thin film transistor by the laser is minimized, and moisture and oxygen from the outside can be prevented from flowing into the flexible organic light emitting diode display 100, thereby preventing deterioration of device performance of the switching and driving thin film transistors (not shown, DTr), thereby preventing the flexible organic light emitting display 100 from being deteriorated. ) can also improve reliability.

3A to 3B are schematic perspective views for explaining a method of separating a manufacturing substrate according to an exemplary embodiment of the present specification.

The substrate 110 includes a first substrate 110a, a light absorption layer 120 and a second substrate 110b. As a material used for manufacturing the substrate 110 , a material such as polyimide having flexibility may be mainly used. In the process of manufacturing the substrate 100 using a material of polyimide, polyimide itself cannot be formed into a thin film like the substrate 110, so a method of curing after applying a polyimide solution on the manufacturing substrate (CG) It can be used to form the substrate 110 made of polyimide.

In the case of disposing the substrate 110 of polyimide on the manufacturing substrate CG, when the substrate 110 is later separated from the manufacturing substrate CG, the substrate 110 cured on the manufacturing substrate CG is the bonding force of the interface. Since this is very high, it cannot be easily separated on the production substrate CG. After disposing the sacrificial layer SL on the production substrate CG, a polyimide solution is applied on the sacrificial layer SL and cured to form the substrate ( 110) is formed.

The sacrificial layer SL is disposed between the substrate 110 and the manufacturing substrate CG, and amorphous silicon (a-Si:H, a-SiC:H) such that the bonding force between molecules is changed by heat and light to lower the bonding strength. ) may be used. Alternatively, a method of separating the manufacturing substrate CG from the substrate 110 may be used by injecting a gas such as H2 into the sacrificial layer SL and then activating the gas to reduce the bonding strength of the sacrificial layer SL. .

In the method of removing the substrate 110 from the manufacturing substrate (CG) according to an embodiment of the present specification, as shown in FIG. 3A , a laser is used in a line beam form through a laser device (CG). A method of irradiating the back of the

The manufacturing substrate CG may be made of a material such as transparent glass, and the irradiated laser reaches the sacrificial layer SL, causing inferiority, and the bonding strength between the manufacturing substrate CG and the sacrificial layer SL is lowered.

After irradiating a line beam type laser on the entire surface through a laser device, as shown in FIG. 3b , the manufacturing substrate CG has a low bonding strength with the sacrificial layer SL, so it can be easily removed. be able to

Thereafter, the sacrificial layer SL may be removed through a process such as etching using a gas.

As described above, the separation process between the manufacturing substrate CG and the substrate 110 is a process of using a line beam through the rear surface of the manufacturing substrate CG, then removing the manufacturing substrate CG and removing the sacrificial layer SL. go through

At this time, the main material constituting the sacrificial layer SL is used as a material constituting the light absorbing layer 120, and the bonding strength of the light absorbing layer 120 is that the sacrificial layer SL absorbs most of the laser energy, This causes a change in bonding strength due to a change in the molecular arrangement of the amorphous silicon included in the sacrificial layer SL, and the remaining energy that is not sufficiently absorbed is transmitted. This transmitted energy is absorbed by the light absorption layer 120, but Since it does not have enough energy to change the bonding force of the absorption layer 120 , there is no problem in bonding strength between the first substrate 110a, the second substrate 110b, and the light absorption layer 120 constituting the substrate 110 . Also, the laser energy does not reach the thin film transistor and the organic light emitting layer on the substrate 110 .

As described above, in the process of separating the substrate 110 using a laser, changes in characteristics of the organic light emitting layer and the thin film transistor or a problem in bonding strength of the organic light emitting layer can be minimized by including the light absorption layer 120 .

4 is a schematic cross-sectional view for explaining the configuration of a light absorption layer according to an embodiment of the present specification.

The configuration of the light absorption layer according to an embodiment of the present specification will be described with reference to FIG. 4, but matters substantially the same as or corresponding to the previous drawings will be omitted or briefly described.

Referring to FIG. 4 , the organic light emitting diode display 200 includes a substrate 210 . The organic light emitting display device 200 is a flexible display device, and the substrate 210 may be a polyimide-based transparent substrate.

A multi-buffer layer 202 is applied on the substrate 210. The multi-buffer layer 202 is a buffer layer in which a plurality of thin films are sequentially stacked, for example, silicon nitride (SiNx) and silicon oxide (SiOx) alternately. can be stacked. Alternatively, an organic film and an inorganic film may be repeatedly laminated alternately.

An interlayer insulating film 209 made of silicon oxide (SiOx) is disposed on the multi-buffer layer 202 , and a light emitting diode E is disposed between the bank layers 219 . The light emitting diode E is electrically connected to the thin film transistor DTr.

The substrate 210 includes a first substrate 210a, a light absorption layer 220, and a second substrate 210b, and is disposed on the sacrificial layer SL of the manufacturing substrate CG.

The sacrificial layer SL is a layer for later separating the manufacturing substrate CG, and is a material whose bonding strength is lowered by a laser, and a material such as amorphous silicon may be used.

On the other hand, the light absorption layer 220 may include a light absorption material constituting the above-described sacrificial layer SL (primary absorption, 1 ^st absorption), the light absorption layer 220 is the manufacturing substrate (CG) substrate ( 210) in the process of separating from the sacrificial layer (SL) by absorbing some of the laser to minimize the energy wavelength of the laser from reaching the semiconductor layer of the thin film transistor (DTr) and the organic light emitting layer of the light emitting diode (E) (second absorption, 2 ^nd absorption).

Meanwhile, the light absorbing layer 220 includes a light absorbing material constituting the sacrificial layer SL, but in the process of separating the manufacturing substrate CG, a phenomenon in which the bonding strength of the sacrificial layer SL is reduced by the laser occurs. Even so, the amount of energy of the laser reaching the light absorption layer 220 is mostly absorbed by the sacrificial layer SL, so that the bonding strength of the light absorption layer 220 itself is not affected.

This has the effect of further enhancing process stability since it is not necessary to greatly increase the precision of laser intensity in the process of separating the manufacturing substrate (CG) using a laser.

Meanwhile, the light absorption layer 220 may further include a light scattering material. Energy such as a laser penetrating the sacrificial layer SL by the light scattering material is dispersed by the light scattering material to further lower the laser wavelength reaching the thin film transistor DTr.

In addition, the light absorption layer 220 may include a conductive material or further include a conductive layer. Since the substrate 210 made of polyimide is easy to accumulate charges and may affect the driving circuit or the light emitting device by the accumulated charges, the light absorption layer 220 includes a conductive material or further includes a conductive layer made of a conductive material. and electrically connected to the circuit unit to discharge the above-described charges, it may be configured to discharge the charges accumulated in the substrate 210 .

5 is a flowchart illustrating a method of manufacturing an organic light emitting diode display having a light absorption layer according to an exemplary embodiment of the present specification.

The method of manufacturing an organic light emitting display device according to an exemplary embodiment of the present specification includes disposing a sacrificial layer on a manufacturing substrate and disposing a first substrate on the sacrificial layer (S110), disposing a light absorption layer on the first substrate, Disposing a second substrate on the light absorption layer (S120), disposing a driving device, a planarization layer, and an organic light emitting layer on the second substrate (S130), a laser on the sacrificial layer through the back surface of the manufacturing substrate irradiating (S140) and separating the manufacturing substrate from the first substrate (S150).

The disposing of the light absorbing layer on the first substrate (S110) may further include disposing the light absorbing layer by mixing a light absorbing material with a polyimide solution, and further applying a conductive material on the light absorbing layer. may include steps.

In the above-described manufacturing method, the step of further coating the conductive material on the light absorption layer; The method may further include the step of forming a conductive layer made of a conductive material after applying the polyimide solution, and the step of further coating the conductive material on the light absorption layer is to apply a light-reflecting material as a conductive material to the polyimide solution. It may further include the step of mixing and disposing.

The light absorption layer described in this specification changes the semiconductor properties of the semiconductor layer in the thin film transistor by the laser irradiated to control the bonding strength of the sacrificial layer on the manufacturing substrate in the process of manufacturing the flexible organic light emitting display using the manufacturing substrate. It is possible to minimize defects such as a change in threshold voltage, and furthermore, it minimizes the phenomenon that the organic light emitting layer is peeled from the pixel electrode, that is, the bonding force of the organic light emitting layer is changed by the laser, so that the organic light emitting diode has high lifespan reliability even in a flexible environment. A method of manufacturing a display device may be provided.

Although the embodiments of the present specification have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be made within the scope without departing from the technical spirit of the present invention. . Accordingly, the embodiments disclosed in the present specification are intended to explain, not to limit the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The protection scope of the present invention should be construed by the claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

102: multi-buffer layer, 103: active buffer layer, 104: lower protective metal
105: active layer (105a: channel region, 105b: source region, 105c: drain region)
106: gate insulating layer
107: gate electrode, 108, 109: first and second interlayer insulating films
110: substrates 110a and 110b; first and second substrates)
120: light absorption layer
111a, 111b: first and second contact holes
113: source electrode, 115: drain electrode
117: protective layer, 119: bulkhead
121: spacer,
123: protective film (123a, 123c: inorganic protective film, 123b: organic protective film)
130: pads 133 and 135: first and second pads, 136: fourth contact hole)
131: wiring, 140: dam
151: active pattern, 153: first metal pattern, 155: second metal pattern, 156: third contact hole, 157: third metal pattern
160: polarizer

Claims (10)

In the organic light emitting display device having an organic light emitting element on a substrate,
The substrate is composed of a first substrate, a light absorption layer and a second substrate,
the light absorption layer on the first substrate;
The second substrate is disposed on the light absorption layer in the order of;
The driving device and the organic light emitting device connected to the driving device are disposed on the second substrate,
The first substrate and the second substrate are transparent substrates made of a plastic-based material.
According to claim 1,
The light absorbing layer is disposed to correspond to both positions of the driving element and the organic light emitting element.
According to claim 1,
The light absorbing layer includes a light scattering material.
According to claim 1,
The light absorption layer includes a conductive material.
5. The method of claim 4,
The conductive material forms an electrical connection with a circuit part at an end of the display device.
disposing a sacrificial layer on a manufacturing substrate;
disposing a first substrate on the sacrificial layer;
disposing a light absorption layer on the first substrate;
disposing a second substrate on the light absorption layer;
disposing a driving device, a planarization layer, and an organic light emitting layer on the second substrate; and
and removing the manufacturing substrate by irradiating a laser to the sacrificial layer through a rear surface of the manufacturing substrate.
7. The method of claim 6,
The step of disposing the light absorption layer on the first substrate,
and disposing the light absorbing layer by mixing a light absorbing material with a polyimide solution.
7. The method of claim 6,
The step of disposing the light absorption layer on the first substrate,
A method of manufacturing an organic light emitting display device comprising the step of further coating a conductive material on the light absorption layer.
9. The method of claim 8,
The step of further applying a conductive material on the light absorption layer,
The method of manufacturing an organic light emitting display device further comprising the step of forming a conductive layer made of a conductive material after applying a polyimide solution.
9. The method of claim 8,
The step of further applying a conductive material on the light absorption layer,
A method of manufacturing an organic light emitting display device, comprising mixing and disposing a conductive material and a material that reflects light in a polyimide solution.

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