KR101481826B1 - Flexible organic light emitting display and manufacturing method thereof - Google Patents

Abstract

The present invention relates to a flexible organic light emitting diode (OLED) display device, and more particularly, to an organic light emitting display device having a flexible performance while forming an organic light emitting display device on a glass substrate and a method of manufacturing the same. A flexible organic light emitting diode display according to an embodiment of the present invention includes a glass substrate having a thickness in a range of 50 to 150 占 퐉, a thin film transistor disposed on the substrate, a light emitting element disposed on the substrate on which the thin film transistor is formed, An anode electrode disposed on the protective layer and electrically connected to a drain electrode of the thin film transistor; a bank layer disposed on the edge region of the protective layer and the anode electrode; An organic light emitting layer disposed on the anode electrode, a bank layer, a cathode electrode disposed on the organic light emitting layer, and an encapsulation layer disposed on the cathode electrode.

Flexible, organic light emitting display, glass substrate

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a flexible organic electro luminescence display device and a manufacturing method thereof,

The present invention relates to a flexible organic light emitting diode (OLED) display device, and more particularly, to an organic light emitting display device having a flexible performance while forming an organic light emitting display device on a glass substrate and a method of manufacturing the same.

Due to the development of the information society, display devices capable of displaying information are actively being developed. The display device includes a liquid crystal display device, an organic electro-luminescence display device, a plasma display panel, and a field emission display device.

In recent years, flexible display devices capable of bending by flexing the flexible performance of a display device have been actively studied.

In particular, since the flexible organic light emitting display device does not require a backlight unit unlike a liquid crystal display device, the flexible organic light emitting display device can minimize thickness and reduce power consumption.

Conventional flexible organic light emitting display devices are mainly manufactured on plastic substrates or metal substrates. However, since the plastic substrate is sensitive to temperature, it is limited to be used as an organic light emitting display device, and the metal substrate has a poor surface roughness characteristic and uses a planarizing organic film. Such a planarizing organic film is used as an organic light emitting display There is a limit.

In addition, when a thin metal substrate is used in a conventional organic light emitting display, there is a problem in process reliability and mass productivity because the substrate can not be easily transported due to substrate deflection or the like.

In addition, when a metal substrate is used in a conventional organic light emitting diode display, the substrate is opaque and only a top emission type organic light emitting display device can be used.

An embodiment of the present invention relates to an organic light emitting diode display, and an object of the present invention is to provide an organic light emitting diode display having a flexible substrate and an organic light emitting diode .

The present invention relates to an organic light emitting diode (OLED) display, and more particularly, to an organic light emitting diode display capable of providing an organic light emitting display device on a glass substrate to provide an image in a top emission type or a bottom emission type, It is an object of the present invention to provide an organic light emitting display.

A flexible organic light emitting diode display according to an embodiment of the present invention includes a glass substrate having a thickness in a range of 50 to 150 占 퐉, a thin film transistor disposed on the substrate, a light emitting element disposed on the substrate on which the thin film transistor is formed, An anode electrode disposed on the protective layer and electrically connected to a drain electrode of the thin film transistor; a bank layer disposed on the edge region of the protective layer and the anode electrode; An organic light emitting layer disposed on the anode electrode, a bank layer, a cathode electrode disposed on the organic light emitting layer, and an encapsulation layer disposed on the cathode electrode.

A method of fabricating a flexible organic light emitting display according to an embodiment includes forming a thin film transistor on a glass substrate, forming a protective layer having a contact hole in which the drain electrode of the thin film transistor is exposed on the glass substrate on which the thin film transistor is formed, Forming an anode electrode electrically connected to a drain electrode of the thin film transistor on the passivation layer, forming a bank layer of an organic material on the edge region of the passivation layer and the anode electrode Forming an organic light emitting layer on the anode electrode; forming a cathode electrode on the bank layer and the organic light emitting layer; forming an encapsulating layer on the cathode electrode; And removing a predetermined thickness from the back surface of the glass substrate so as to be in the range of from 탆 to 150 탆 And that is characterized.

In the flexible organic light emitting display according to the embodiment, an organic light emitting display device is formed on a glass substrate. Thus, the organic light emitting display device can be used as a two-sided display device having a flexible performance as well as a top emission type or a bottom emission type.

The flexible organic light emitting display according to the embodiment can be manufactured by applying the mass production process of a flat panel organic light emitting display device made of a hard glass substrate, thereby reducing the manufacturing cost and the investment cost of the process facility.

In addition, the embodiment can provide a flexible performance by forming an organic light emitting display device using a hard glass substrate and then etching the hard glass substrate, thereby simplifying the process and facilitating transfer between processes, thereby improving process yield There is an effect that can be made.

The organic light emitting display according to the embodiment is robust and stable at a high temperature process temperature and requires no additional components and no additional process as compared with the organic light emitting display manufactured using a metal substrate, .

Hereinafter, an OLED display according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. The embodiments may be modified in various forms, and the scope of the present invention should not be construed as being limited by the above-described embodiments. These embodiments are provided to enable those skilled in the art to more fully understand the present invention. Therefore, the shapes of elements and the like in the drawings are exaggerated in order to emphasize a clearer explanation. In the drawings, the size and thickness of an apparatus may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

1 is a cross-sectional view illustrating a flexible organic light emitting display according to an embodiment of the present invention.

Referring to Fig. 1, a substrate 1 is prepared.

The substrate 1 may be a glass substrate.

The thickness (a) of the substrate 1 may be 50 to 150 mu m.

The substrate 1 is a product obtained by preparing an organic light emitting display using a hard glass substrate having a thickness larger than the thickness of the substrate 1, and then etching the hard glass substrate to a thickness of the hard glass substrate.

The embodiment can manufacture the organic light emitting display device using the hard glass substrate, so that it can be manufactured using existing mass production equipment, so there is no need to develop a separate manufacturing equipment, and the process stability is also excellent.

In addition, in the embodiment, after the organic light emitting display device is manufactured, the rear surface of the hard glass substrate is subjected to at least one of wet etching and polishing to remove a predetermined thickness, thereby forming a flexible organic A light emitting display device can be manufactured.

A reinforcement film (45) is disposed on the back surface of the substrate (1).

The reinforcing film 45 is attached to the back surface of the etched substrate 1 in order to reinforce the reinforcing film 45 because the substrate of the flexible organic light emitting display device is made of a thin glass substrate and is vulnerable to external impact.

An adhesive (not shown) may be interposed between the reinforcing film 45 and the back surface of the substrate 1.

The reinforcing film 45 may be formed to have a thickness of 100 μm to 300 μm and the flexibility of the reinforcing film 45 may be made of a transparent plastic material superior to the flexibility of the substrate 1. have.

For example, the reinforcing film 45 may be at least one of PET (polyethylene terephthalate), PEN (ethylene naphthalate), PI (polyimide), PMMA (polymethyl methacrylate), PC (polycarbonate), PS (polystyrene) One can be included.

A buffer layer may be disposed on the upper surface of the substrate 1 in order to improve the flexibility of the OLED display device. However, the buffer layer may be omitted.

At least one thin film transistor (18) is disposed in the pixel region on the substrate (1). That is, a gate electrode 9 is disposed on the substrate 1, a gate insulating film 11 is disposed on the gate electrode 9, and a semiconductor film 11 is formed on the gate insulating film 11, The layer 13 and the source / drain electrodes 15 and 17 can be disposed. The semiconductor layer 13 may be made of amorphous silicon (a-Si) or polysilicon (poly-Si).

A protective layer 23 is disposed on the substrate 1 on which the thin film transistor 18 is formed.

The protective layer 23 according to the embodiment may be formed of a double layer of an inorganic film 19 made of an inorganic material and an organic film 21 made of an organic material, as shown in FIG. The present invention is not limited thereto, and the protective layer 23 may be composed of a single layer made of only an inorganic material.

The inorganic material may be silicon oxide (SiOx) or silicon nitride (SiNx). The organic material may be an acryl based organic material or a polyimide.

The inorganic film 19 may have a thickness in the range of 100 Å to 3000 Å, and the organic film 21 may have a thickness in the range of 500 Å to 3 mm.

The thin film transistor 18 is protected by the organic film 19, and planarization can be performed, thereby facilitating subsequent manufacturing processes.

On the other hand, when the protective layer 23 is composed of a single layer made of an inorganic material, the thickness of the protective layer 23 may range from 500 Å to 4000 Å.

A reflective layer 25 is disposed on the protective layer 23 for reflecting the light generated in the organic light emitting layer 30 to be disposed later and an anode electrode 27 is disposed on the reflective layer 25. The anode electrode 27 may be electrically connected to the drain electrode 17 through the reflective layer 25 and the protective layer 23.

The anode electrode 27 may be made of a transparent metal material. For example, the anode electrode 27 may be formed of indium-tin-oxide or indium-zinc-oxide. The reflective layer 25 may be any material capable of reflecting light.

The anode electrode 27 provides a signal to the organic light emitting layer 30 via the thin film transistor 18.

The reflective layer 25 and the anode electrode 27 may be disposed in the pixel region. The pixel region is an area defined by the intersection of a gate line and a data line, not shown. In the organic light emitting diode display, such pixel regions may be arranged in a matrix form, and light having a color may be generated for each pixel region. And the light generated for each pixel region is mixed to realize a full color.

The bank layer 29 is disposed in the edge region of the protective layer 23 and the anode electrode 27. [ The bank layer 29 may be formed to prevent the damage of the organic light emitting layer 30 corresponding to the edge region of the anode electrode 27 due to the high electric field generated in the edge region of the anode electrode 27, .

Therefore, the bank layer 29 can be disposed on the edge regions of the protective layer 23 and the anode electrode 27 between the pixel regions.

In the embodiment, the bank layer 29 may be made of an organic material. The organic material is excellent in the flexible performance as compared with the inorganic material, and the bank layer 29 made of the inorganic material is poor in flexibility and can cause the filling of the cathode electrode 31 to be disposed later due to bending or the like. A bank layer 29 made of an organic material is employed for improving the flexible characteristics.

The organic material may be an acryl based organic material or a polyimide.

The bank layer 29 may have a thickness in the range of 1000 ANGSTROM to 3 mu m.

The organic light emitting layer 30 is disposed on the anode electrode 27 except for the bank layer 29. [ The organic light emitting layer 30 may be a red organic light emitting layer for emitting red light, a green organic light emitting layer for emitting green light, and a blue organic light emitting layer for emitting blue light. The red organic light emitting layer, the green organic light emitting layer, and the blue organic light emitting layer may be disposed in each pixel region.

A cathode electrode 31 is disposed on the bank layer 29 and the organic light emitting layer 30. The cathode electrode 31 may be made of a transparent metal material. For example, the cathode electrode 31 may be indium-tin-oxide or indium-zinc-oxide.

The sealing layer 41 is disposed on the cathode electrode 31 so that moisture or oxygen is not penetrated into the organic light emitting layer 30. [

The sealing layer 41 may include at least one of an organic film 33, an inorganic film 35, an adhesive film 37, a protective film 39 and a polarizing plate.

The organic film 33 may be made of an organic material. For example, the organic film 33 may be made of a low molecular organic material such as LiF or Ca. In addition, the organic film 33 may be made of a UV curable resin.

The organic film 33 may be disposed in contact with the bank layer 29 and the cathode electrode 31. [ The organic film 33 can be disposed to primarily block external moisture or oxygen penetration, enhance flexible performance, and enhance planarization performance. The organic film 33 may have a thickness in the range of 200 Å to 2000 Å in the case of a low molecular organic material and may have a thickness in the range of 1000 Å to 5 탆 in the case of a high molecular organic material.

The inorganic film 35 can be disposed to secondarily block the penetration of moisture or oxygen from the outside. The inorganic film 35 may be made of an inorganic material. For example, the inorganic film 35 may be made of aluminum oxide (AlxOy), silicon oxide (SiOx), or silicon oxynitride (SiOxNy). The inorganic film may have a thickness in the range of 500 ANGSTROM to 2000 ANGSTROM.

The adhesive film 37 is a member for attaching the protective film 39 to the inorganic film 35, and may include an adhesive material and a moisture absorbent. The penetration of moisture or oxygen outside can be blocked by the moisture absorbent contained in the adhesive film 37. [

The protective film 39 is a member for protecting all the devices manufactured by the manufacturing process including the organic light emitting layer 30 from, for example, scratches, and may be made of a plastic material. For example, the protective film 39 may be made of polyethylene terephthalate, polyimide, polyether sulfone, polymethyl ethacrylate (PMMA), polycarbonate (PC), or polystyrene . In particular, the protective film 39 may be formed of a multi-layered thin film to prevent water and oxygen penetration.

Therefore, in the sealing layer 41 of the present invention, each of the organic film 33, the inorganic film 35, the adhesive film 37 and the protective film 39 blocks external moisture or oxygen, It is possible to prevent the defective element due to penetration of moisture or oxygen.

FIGS. 2 to 7 are process diagrams illustrating a manufacturing process of the flexible organic light emitting display according to the present invention.

First, as shown in Fig. 2, a thick disc 1a having a thickness in the range of about 1 mm is provided.

The original plate 1a is transported to the process equipment for manufacturing the OLED display.

The circular plate 1a may be made of a glass substrate.

As shown in Fig. 3, a thin film transistor 18 is formed on the circular plate 1a.

That is, the first metal material is deposited on the inorganic film 5 and patterned to form the gate line and the gate electrode 9. A gate insulating material is deposited on the gate electrode 9 to form the gate insulating film 11. [

Amorphous silicon and a second metal material are sequentially deposited on the gate insulating film 11 and patterned to form the semiconductor layer 13 and the source / drain electrodes 15 and 17. Although not shown in FIG. 2B, a data line may be formed along with the source / drain electrodes 15 and 17.

Therefore, the thin film transistor 18 can be formed by the gate electrode 9, the semiconductor layer 13, and the source / drain electrodes 15 and 17.

An inorganic film 19 made of an inorganic material and a protective layer 23 having a double layer of an organic film 21 made of an organic material are formed on the original plate 1a on which the thin film transistor 18 is formed. That is, the inorganic material may be silicon oxide (SiOx) or silicon nitride (SiNx), and the organic material may be an acryl-based organic material or polyimide.

The inorganic film 19 may have a thickness in the range of 100 Å to 3000 Å, and the organic film 21 may have a thickness in the range of 500 Å to 3 mm.

The organic film 21 protects the thin film transistor 18 and can be planarized, thereby facilitating subsequent manufacturing processes.

The thickness of the protective layer 23 may be in the range of 500 Å to 4000 Å.

The protective layer 23 may be formed with the contact hole 24 in which the drain electrode 17 of the thin film transistor 18 is exposed.

As shown in FIG. 4, a reflective material is deposited on the protective layer 23 and patterned to form the reflective layer 25. The reflective layer 25 is not formed in the regions except for the pixel region, for example, the gate line region, the data line region, the thin film transistor 18 region, and the contact hole region. The reflective layer 25 may be formed of any material for reflecting light generated in the organic light emitting layer 30 formed later.

A transparent first transparent material is deposited on the reflective layer 25 and patterned to form the anode electrode 27. The first transparent material may be indium-tin-oxide or indium-zinc-oxide. The anode electrode 27 may be electrically connected to the drain electrode 17 of the thin film transistor 18 through the contact hole.

The reflective layer 25 and the anode electrode 27 may be disposed in the pixel region. The pixel region is an area defined by the intersection of a gate line and a data line, not shown. In the organic light emitting diode display, such pixel regions may be arranged in a matrix form, and light having a color may be generated for each pixel region. And the light generated for each pixel region is mixed to realize a full color.

An organic material is deposited and patterned on the reflective layer 25 and the anode electrode 27 to form a protective layer 23 between the pixel regions and an edge region of the anode electrode 27, (29). The bank layer 29 may be formed to prevent the damage of the organic light emitting layer 30 corresponding to the edge region of the anode electrode 27 due to the high electric field generated in the edge region of the anode electrode 27, .

In the present invention, the bank layer 29 may be made of an organic material. The organic material is excellent in the flexible performance as compared with the inorganic material and the bank layer 29 made of the inorganic material is poor in flexibility and can cause peeling of the cathode electrode 31 to be disposed later due to bending or the like. A bank layer 29 made of a material is employed.

The organic material may be an acryl based organic material or a polyimide.

The bank layer 29 may have a thickness in the range of 1000 ANGSTROM to 3 mu m.

The organic light emitting layer 30 is disposed on the anode electrode 27 except for the bank layer 29. [ The organic light emitting layer 30 may be a red organic light emitting layer for emitting red light, a green organic light emitting layer for emitting green light, and a blue organic light emitting layer for emitting blue light. The red organic light emitting layer, the green organic light emitting layer, and the blue organic light emitting layer may be disposed in each pixel region.

A transparent second transparent material is deposited on the bank layer 29 and the organic light emitting layer 30 to form the cathode electrode 31. [ The second transparent material may be indium-tin-oxide or indium-zinc-oxide.

As shown in FIG. 6, the sealing layer 41 is formed on the cathode electrode 31 so that moisture or oxygen does not penetrate into the organic light-emitting layer 30.

That is, an organic material having a thickness in the range of 200 Å to 2000 Å is deposited, and then an inorganic material having a thickness in the range of 500 Å to 2000 Å is sequentially deposited to form the organic film 33 and the inorganic film 35.

The organic material may have a thickness of 1000 Å to 5 袖 m for a polymer material.

The organic material may be a low molecular organic material such as LiF or Ca or a polymer organic material. The organic film 33 can be disposed to primarily block external moisture or oxygen penetration, enhance flexible performance, and enhance planarization performance.

The organic film 33 may be a thermosetting resin or a UV-curable resin.

The inorganic film 35 can be disposed to secondarily block the penetration of moisture or oxygen from the outside. The inorganic material may be composed of aluminum oxide (AlxOy), silicon oxide (SiOx), or silicon oxynitride (SiOxNy).

The adhesive film 37 may be included or adhered to the protective film 39. [

The adhesive film 37 is a member for attaching the protective film 39 to the inorganic film, and may include an adhesive material and a moisture absorbent. The penetration of moisture or oxygen outside can be blocked by the moisture absorbent contained in the adhesive film 37. [

The protective film 39 is a member for protecting all the devices manufactured by the manufacturing process including the organic light emitting layer 30 from, for example, scratches, and may be made of a plastic material. For example, the protective film 39 may be made of polyethylene terephthalate, polyimide, polyether sulfone, polymethyl ethacrylate (PMMA), polycarbonate (PC), or polystyrene . In particular, the protective film 39 may be formed of a multi-layered thin film to prevent water and oxygen penetration.

The protective film 39 is attached on the inorganic film 35 via the adhesive film.

The sealing layer 41 including at least one of the organic film 33, the inorganic film 35, the adhesive film 37, the protective film 39, and the polarizing plate can be formed.

Therefore, in the sealing layer 41 of the present invention, each of the organic film 33, the inorganic film 35, the adhesive film 37 and the protective film 39 blocks external moisture or oxygen, It is possible to prevent the defective element due to penetration of moisture or oxygen.

Subsequently, as shown in Fig. 7, the rear surface of the original plate 1a is wet-etched or polished to form a substrate 1 having a flexible performance with a thickness (a) ranging from 50 m to 150 m.

The organic light emitting diode display thus manufactured has a flexible characteristic by forming the organic light emitting display device on the hard disk 1a and etching or polishing the disk 1a after the sealing is completed. The flexible organic light emitting display fabricated by this method is susceptible to external impact, so that a reinforcing film 45 is attached to the back surface of the etched substrate 1 in order to reinforce it.

An adhesive (not shown) may be interposed between the reinforcing film 45 and the back surface of the substrate 1.

The reinforcing film 45 may be formed to have a thickness of 100 μm to 300 μm and the flexibility of the reinforcing film 45 may be made of a transparent plastic material superior to the flexibility of the substrate.

For example, the reinforcing film 45 may be at least one of PET (polyethylene terephthalate), PEN (ethylene naphthalate), PI (polyimide), PMMA (polymethyl methacrylate), PC (polycarbonate), PS (polystyrene) One can be included.

In the flexible organic light emitting display according to the embodiment, an organic light emitting display device is formed on a glass substrate. Thus, the organic light emitting display device can be used as a two-sided display device having a flexible performance as well as a top emission type or a bottom emission type.

The flexible organic light emitting display according to the embodiment can be manufactured by applying a mass production process of a flat panel organic light emitting display device made of a hard glass substrate, thereby reducing the manufacturing cost and the investment cost of the process equipment.

In addition, the embodiment can provide a flexible performance by forming an organic light emitting display device using a hard glass substrate and then etching the hard glass substrate, thereby simplifying the process and facilitating transfer between processes, thereby improving process yield There is an effect that can be made.

The organic light emitting display according to the embodiment is robust and stable at a high temperature process temperature and requires no additional components and no additional process as compared with the organic light emitting display manufactured using a metal substrate, .

1 is a cross-sectional view illustrating a flexible organic light emitting display according to an embodiment of the present invention.

FIGS. 2 to 7 are process diagrams illustrating a manufacturing process of the flexible organic light emitting display according to the present invention.

Claims (10)

A glass substrate having a thickness in the range of 50 탆 to 150 탆; A thin film transistor disposed on the substrate; A protective layer disposed on the substrate on which the thin film transistor is formed and having a contact hole in which a drain electrode of the thin film transistor is exposed; An anode electrode disposed on the protective layer and directly connected to the drain electrode of the thin film transistor through the contact hole; A bank layer disposed on the protective layer and an edge region of the anode electrode; An organic light emitting layer disposed on the anode electrode; A cathode electrode disposed on the bank layer and the organic light emitting layer; And And an encapsulation layer disposed on the cathode electrode, Wherein the protective layer comprises an inorganic film formed on the entire surface of the glass substrate and an organic film formed on the inorganic film so as to be in contact with the thin film transistor, Wherein a reflective layer is formed between the anode electrode and the organic layer, wherein a portion corresponding to the gate line region, the data line region, the thin film transistor region, and the contact hole regions except the pixel region is removed. The method according to claim 1, Wherein the bank layer is made of an organic material. The method according to claim 1, Wherein the sealing layer comprises at least one of an organic film, an inorganic film, an adhesive film, a protective film, and a polarizing plate. The method according to claim 1, Wherein a reinforcing film having a thickness in the range of 100 mu m to 300 mu m is disposed on the back surface of the glass substrate. 5. The method of claim 4, The reinforcing film includes at least one of PET (polyethylene terephthalate), PEN (ethylene naphthalate), PI (polyimide), PMMA (polymethyl methacrylate), PC (polycarbonate), PS (polystyrene) The organic light emitting display device comprising: 5. The method of claim 4, Wherein the reinforcing film is more flexible than the glass substrate. The method according to claim 1, Wherein the thin film transistor includes a semiconductor layer made of one of amorphous silicon (a-Si) and polysilicon (poly-Si). Forming a thin film transistor on a glass substrate; Forming a protective layer having a contact hole in which a drain electrode of the thin film transistor is exposed on the glass substrate on which the thin film transistor is formed; Forming a reflective material on the protective layer, forming a reflective layer on the protective layer by removing the reflective material from the gate line region, the data line region, the thin film transistor region, and the contact hole region of the protective layer except for the pixel region, ; Forming an anode electrode electrically connected to the drain electrode of the thin film transistor through the contact hole of the protective layer and stacked on the reflective layer; Forming a bank layer of an organic material on the protective layer and the edge region of the anode electrode; Forming an organic light emitting layer on the anode electrode; Forming a cathode electrode on the bank layer and the organic light emitting layer; Forming an encapsulating layer on the cathode electrode; And And removing a predetermined thickness from the back surface of the glass substrate so that the thickness of the glass substrate is in a range of 50 to 150 占 퐉. 9. The method of claim 8, Removing a predetermined thickness from the back surface of the glass substrate, Wherein the glass substrate is removed by a predetermined thickness using at least one of a wet etching method and a polishing method. 9. The method of claim 8, After the step of removing the predetermined thickness from the back surface of the glass substrate, Wherein a reinforcing film having a thickness in the range of 100 mu m to 300 mu m is attached to the back surface of the glass substrate.

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