KR20080047777A - Organic light emitting display device and manufacturing method thereof - Google Patents

Abstract

The present invention relates to an organic light emitting display device and a manufacturing method thereof, and more particularly, to a substrate having a light emitting area and a non-light emitting area; A thin film transistor formed in the non-light emitting region and including a gate electrode and a source / drain electrode; A passivation layer having a via hole on the thin film transistor; A first electrode connected to any one of the source / drain electrodes through the via hole; A pixel defining layer disposed on the first electrode and including an opening to expose a portion of the first electrode, the pixel defining layer having a groove and a passage on the non-light emitting area; An organic layer divided by the pixel defining layer, the organic layer layer exposing a portion of the groove and the passage on the pixel defining layer and having at least a light emitting layer on the exposed first electrode region; And a second electrode disposed on the organic layer, and an organic light emitting display device.

In addition, a substrate is provided, a thin film transistor including a gate electrode is formed on the substrate, a protective film including a via hole is formed on the thin film transistor, a first electrode is formed on the protective film, and the half- A pixel defining layer is formed on the first electrode by using the tone mask and has a groove and a passage, and the organic light emitting layer is formed on the first electrode exposed by the pixel defining layer by using a laser thermal transfer method. The present invention relates to a method of manufacturing an organic light emitting display device, including forming an organic layer and forming a second electrode on the organic layer.

Description

Organic Light Emitting Display and Method for Manufacturing the Same {Organic Light Emitting Display And Method For Manufacturing The Same}

1 is a cross-sectional view illustrating a structure of a conventional full color organic light emitting display device;

2 is a cross-sectional view showing the structure of a conventional laser transfer donor film,

3 is a view showing a transfer model when using a donor film,

4 is a cross-sectional view illustrating a conventional organic light emitting display device having a gas vent groove.

5 is a plan view showing a conventional gas vent groove,

6A is a cross-sectional view of a method of manufacturing an organic light emitting display device using a half-tone mask according to the present invention;

6B is a cross-sectional view of an organic light emitting display device according to the present invention;

7A is a plan view of a conventional organic light emitting display device.

7B is a plan view of an organic light emitting display device according to the present invention;

8 is a cross-sectional view showing a method of forming an organic film layer using a laser thermal transfer method.

The present invention relates to an organic light emitting display device, and more particularly, to condensation of gas remaining in a pixel internal space during donor film lamination using a laser thermal transfer method using a groove and a passage formed on a pixel definition layer. Therefore, the present invention relates to an organic light emitting display device and a method of manufacturing the same, which can reduce edge open defects by preventing non-transfer occurring in the pixel edge region to be finally transferred.

Hereinafter, a conventional technique will be described with reference to FIGS. 1 to 5.

1 is a cross-sectional view showing the structure of a conventional full color organic electroluminescent device.

Referring to FIG. 1, the first electrode 200 is patterned and formed on the substrate 100. The first electrode 200 is formed of a transparent electrode in the case of a bottom emission structure, and is formed of a conductive metal including a reflective film in the case of a top emission structure.

A pixel defining layer PDL 300 is formed of an insulating material to define a pixel area on the first electrode 200 and to insulate the emission layer.

An organic layer including the organic light emitting layers 33, R, G, and B is formed in the pixel region defined as the pixel defining layer PDL 300, and the organic layer 33 is a hole injection layer in addition to the organic light emitting layer, It may further include a hole transport layer, a hole suppression layer, an electron transport layer and an electron injection layer. The organic light emitting layer may be a high molecular material and a low molecular material.

Then, a second electrode 400 is formed on the organic layer 33. The second electrode 400 is formed of a conductive metal layer including a reflective film when the first electrode 200 is a transparent electrode, and is formed of a transparent electrode when the first electrode is a conductive metal layer including a reflective film. Then, the organic electroluminescent display is completed by sealing the organic electroluminescent display.

2 is a cross-sectional view showing the structure of a conventional laser transfer donor film.

Here, in the case of forming the light emitting layer using a conventional laser thermal transfer method, as shown in Figure 2, the conventional laser transfer donor film 34 is a base film 31, a light-heat conversion layer 32 ), And a transfer layer 33.

3 illustrates a transfer model in the case of using a conventional donor film 34. As shown in FIG. 3, the transfer layer expands and separates from the donor film as the light-heat changing layer expands during laser irradiation. Transferred to a substrate of an electroluminescent display.

However, in the organic electroluminescent display, a portion B in which the edge portion of the pixel region is not transferred due to the condensation of the residual gas A present inside the lamination of the donor film is generated. Such failures are called edge open failures (edge open or non-transfer failures), which have a very detrimental effect on device life and characteristics.

In order to solve the conventional problem, when the light emitting layer is formed by a transfer method when manufacturing an organic light emitting display device, the donor film may be prevented from being transferred in the region to be finally transferred due to the condensed residual gas present in the pixel. There is a method of solving the problem by creating a passage through which gas escapes in the pixel defining layer existing on the first electrode.

4 is a cross-sectional structure of a method of a conventional organic light emitting display device.

Referring to FIG. 4, the first electrode 282 is formed on the entire surface of the substrate 200 made of any one of glass, quartz, plastic, and metal. Then, an insulating film (not shown) is laminated on the entire surface. The insulating material may be formed of an organic material or an inorganic material.

Thereafter, the insulating material is etched to form a pixel definition layer 290 having at least one gas vent groove A. A method of forming the pixel definition layer 290 having the gas vent grooves A may generally be a wet etching method or a dry etching method. At this time, the wet etching is performed to etch the insulating material using an etchant diluted with acid and water having a temperature of less than 200 ℃, and after etching to form a pixel defining layer having at least one gas vent groove. In the case of such wet etching, a neutralization process and a washing process to neutralize the acid must be performed. In the dry etching, the pixel defining layer having at least one gas vent groove is formed on the insulating layer by using the photoresist pattern formed in the photolithography process. In the case of performing such dry etching, a reaction gas is generally used, and after the dry etching, a process of removing the photoresist using a high concentration of alkali solution and a cleaning process using plasma treatment should be performed.

The pixel region having at least one gas vent groove formed through the etching process as described above is formed in the following form.

5 is a planar structure diagram of a pixel area having a gas vent groove according to the above method. Referring to FIG. 5, when the donor film 34 including at least the base film, the light-to-heat conversion layer, and the transfer layer is disposed on the entire upper surface of the pixel region, the position of the gas vent groove Z along the laser thermal transfer direction is In general, it is formed in the pixel defining layer 310 of the pixel edge portion. That is, the gas vent groove may be formed in the transfer direction and the horizontal direction or may be formed in the direction perpendicular to the transfer direction, and preferably in the pixel definition layer 310 of the pixel edge portion, which is contrasted with the pixel edge portion where the laser thermal transfer starts. At least one is formed perpendicular to the transfer direction (C), horizontal (P) or diagonal (D) to prevent the gas from condensing on the pixel edge portion.

Subsequently, an organic layer is formed in the emission region exposed by the pixel definition layer 310. The organic layer is formed by a laser thermal transfer method including a minimum light-to-heat conversion layer and a transfer layer, and laminating a donor film formed in multiple layers to form a light emitting layer. After that, a second electrode was formed to complete the organic light emitting display device.

However, the above method is performed by separately performing wet etching or dry etching after forming a pixel defining layer having an opening on the first electrode to form a gas vent groove necessary for preventing defects due to residual gas in the pixel region. The disadvantage is that the process time is long and the process is complicated.

The technical problem to be solved by the present invention is to solve the above problems of the prior art, and when the light emitting layer is formed by a laser transfer method in manufacturing an organic light emitting display device, the transfer is finally performed due to the condensed residual gas present in the pixel. Forming a pixel definition layer having grooves and passages through which a gas can be discharged using a half-tone mask to escape the gas present in the upper portion of the first electrode so as to prevent a defect of the donor film from being transferred in the region where the donor film is not transferred. An organic light emitting display device and a method of manufacturing the same are provided.

The present invention relates to an organic light emitting display device and a manufacturing method thereof, and more particularly, to a substrate having a light emitting area and a non-light emitting area; A thin film transistor formed in the non-light emitting region and including a gate electrode and a source / drain electrode; A passivation layer having a via hole on the thin film transistor; A first electrode connected to any one of the source / drain electrodes through the via hole; A pixel defining layer disposed on the first electrode and including an opening to expose a portion of the first electrode, the pixel defining layer having a groove and a passage on the non-light emitting area; An organic layer divided by the pixel defining layer, the organic layer layer exposing a portion of the groove and the passage on the pixel defining layer and having at least a light emitting layer on the exposed first electrode region; And a second electrode disposed on the organic layer, and an organic light emitting display device.

In addition, a substrate is provided, a thin film transistor including a gate electrode is formed on the substrate, a protective film including a via hole is formed on the thin film transistor, a first electrode is formed on the protective film, and the half- A pixel defining layer is formed on the first electrode by using the tone mask and has a groove and a passage, and the organic light emitting layer is formed on the first electrode exposed by the pixel defining layer by using a laser thermal transfer method. The present invention relates to a method of manufacturing an organic light emitting display device, including forming an organic layer and forming a second electrode on the organic layer.

Hereinafter, the present invention will be described in more detail with reference to FIGS. 6A to 8.

6A and 6B illustrate cross-sectional structures of an organic light emitting display device according to an exemplary embodiment of the present invention.

Referring to FIG. 6A, after forming a buffer layer 401 on a substrate 400 made of any one of glass, quartz, plastic, and metal, amorphous silicon is formed through a method such as PECVD, LPCVD, and sputtering. After the crystallization and patterning of the amorphous silicon, a semiconductor layer 402 is formed, and a gate insulating film 403 is formed over the entire surface of the semiconductor layer 402 and the substrate. Then, after the gate electrode 404 is formed on the gate insulating film 403, an interlayer insulating film 405 is formed on the gate electrode 404. The insulating film is made of silicon nitride, silicon oxide film, or a composite layer thereof. Thereafter, contact holes are formed on the gate insulating film 403 and the interlayer insulating film 405 to form source / drain electrodes 406a and 406b, and then a protective film (or film) is formed over the entire surface of the substrate including the source / drain electrodes. 407). Then, a planarization film 408 made of an inorganic material or an organic material such as polyimide is formed on the protective film 407.

A via hole is formed in the planarization layer 408 and the passivation layer 407 on the planarization layer 408 to form a first electrode 409 connected to one of the source / drain and filling the via hole. In this case, the first electrode 409 is an anode electrode and is formed of one type of transparent electrode selected from the group consisting of ITO, IZO, and In 2 O 3 including a reflective film in the case of a top light emitting structure, and a transparent electrode in the case of a bottom light emitting structure. do. In addition, when the first electrode 409 is formed, the groove 601 is formed in the upper portion of the via hole due to the via hole, and the groove 602 is also formed on the pixel defining layer.

Subsequently, an insulating material is stacked on the first electrode 409 and the entire surface to form a pixel definition layer 410. The insulating material may be formed of an organic material or an inorganic material. The organic material may be formed of one selected from the group consisting of photosensitive resins such as BCB (benzocyclobutene), acrylic photoresist, phenolic photoresist, and polyimide photoresist, but is not limited thereto. If the thickness of the pixel defining layer is too thin, the uniformity of the film is reduced, so that patterning of the light emitting layer becomes difficult, so that the thickness of the pixel defining layer is 0.5 μm or more, and 3.0 μm or less for efficiency of laser thermal transfer energy and effective transfer of the light emitting layer.

Subsequently, a pattern is formed on the pixel definition layer 410 using a half-tone mask. As shown in the figure, the half-tone mask is formed by depositing a chromium silicide layer 502 on a quartz substrate 501 and forming a blocking layer 503 at which light is blocked 100% on the half-tone mask. Form 500. The half-tone mask 500 includes a region (511: transmission region) where light is transmitted 100%, a region (512: blocking region) where light is blocked 100% by the blocking film 503, and about 30 to 70% of the light. Transmissive region 513 (half-tone region). The blocking layer is made of chromium, and the photoresist pattern on the half-tone region 513 of the photoresist pattern using the half-tone mask 500 is deposited lower than the photoresist pattern on other regions.

FIG. 6B is a cross-sectional view of the pixel defining layer 410 having the passage 603 formed using the half-tone mask 513. It can be seen that the pixel definition layer 410 having the passage 603 connecting the groove and the pixel region is formed by using the half-tone mask. Then, when the organic layer is formed, a portion of the passage must be exposed because residual gas is passed through the passage.

Referring to FIGS. 7A and 7B, FIG. 7A is a plan view showing a conventional pixel region, and FIG. 7B is a view illustrating a connection between the groove 602 and the pixel region 604 on the pixel definition layer according to the present invention. A planar structure diagram of a pixel region having a passage 603.

Referring to FIG. 7B, when the donor film 34 including at least the base film, the light-to-heat conversion layer, and the reflective layer is located above the pixel area, the position of the passage along the laser thermal transfer direction is spaced perpendicularly to the via hole. The grooves 602 and the pixel regions 604 formed in the pixel definition layer formed in FIG. At this time, the width of the passage 603 is formed within 30% of the length of the surface of the pixel region which is in contact with the passage, and the depth of the groove is 30% to 90% of the thickness of the pixel definition layer. The reason is that in the case of the minimum thickness of the pixel definition film having a minimum depth of 0.5 μm, the depth of the groove has a fine protrusion shape of the surface of the first electrode when the depth of the groove is 0.35 μm (30% of the thickness of the pixel definition film) This is because pinholes are generated in the pixel definition layer due to fine dust, and when the depth of the groove is less than 0.05 μm (90% of the thickness of the pixel definition layer), the groove is blocked by the bend of the donor film in the lamination process of the donor film.

Then, an organic layer is formed in the light emitting region exposed by the pixel defining layer 413. The organic layer is formed by a laser thermal transfer method including a minimum light-to-heat conversion layer and a transfer layer, and laminating a donor film formed in multiple layers to form a light emitting layer.

8 is a cross-sectional view showing a method of forming an organic film layer using a laser thermal transfer method.

Referring to FIG. 8, the base film layer 31 of the donor film 34 having the structure as described above and used for the laser thermoelectric method is irradiated with a laser 40 on the base film. As it is transferred to the heat conversion layer 32, it is generally formed of a transparent material. For example, it may be one or more polymer materials selected from the group consisting of polyethylene terephthalate, polyester, polyacryl, polyepoxy, polyethylene, and polystyrene, or may be formed of a glass substrate, and preferably formed of polyethylene terephthalate.

In addition, the light-to-heat conversion layer 32 formed on the base film layer 31 is a layer that absorbs light in the infrared-visible light region and converts a portion of the light into heat, and has a suitable optical density. ), And preferably includes a light absorbing material for absorbing light. Here, the light-to-heat conversion layer 32 may be made of a metal film made of Al, Ag, oxides and sulfides thereof, or an organic film made of a polymer including carbon black, graphite, or an infrared dye. The metal film may be formed by vacuum deposition, electron beam deposition, or sputtering, and the organic film may be formed by one of roll coating, gravure, extrusion, spin coating, and knife coating as a conventional film coating method. Can be.

Subsequently, the transfer layer 33 formed on the light-to-heat conversion layer 32 may be made of a low molecular or high molecular organic material.

In this case, an intermediate layer may be further included between the light-to-heat conversion layer 32 and the transfer layer 33 to improve transfer characteristics, but may not necessarily be included. The intermediate layer may be at least one of a gas generating layer (not shown), a buffer layer (not shown), and a metal reflective film (not shown).

When the gas generating layer absorbs light or heat, it causes a decomposition reaction to release nitrogen gas or hydrogen gas, thereby providing a transfer energy, and may be made of pentaerythrite tetranitrate or trinitrotoluene.

In addition, the buffer layer serves to prevent the light-heat absorbing material from contaminating or damaging the transfer layer formed in a subsequent process and to control the adhesion with the transfer layer to improve transfer pattern characteristics. Here, the buffer layer may be made of a metal oxide, a nonmetal inorganic compound or an inert polymer.

The metal reflective film not only serves to transmit more energy to the light-to-heat conversion layer 32 by reflecting the laser irradiated to the base film layer 31 of the donor film 34 but also to introduce a gas generating layer. In this case, the gas generated from the gas generating layer serves to prevent the penetration of the transfer layer (33).

The organic film layer (33 ＇) formed using the donor film 34 having the above structure includes at least an organic light emitting layer, and in addition, an electron injection layer, an electron transport layer, a hole injection layer, a hole transport layer, a hole suppression layer, etc. It can be included and formed. The organic layer 33 'is formed while exposing a portion of the groove and the passage on the pixel defining layer, thereby preventing gas from penetrating into the transfer layer 33.

Subsequently, a second electrode (not shown) is formed on the organic layer to complete the organic light emitting device. In this case, the second electrode is a cathode electrode formed of a transparent electrode in the case of a top light emitting structure, and in the case of a bottom light emitting structure of the electrode including a reflective electrode or a reflective film Ca, Mg, MgAg, Ag, Ag alloy, Al and Al alloy It is formed of one transparent or transflective electrode selected from the group of.

As described above, in the case of forming the pixel defining layer having the passage and the groove on the first electrode, the transfer layer of the donor film in the pixel region to be finally transferred by discharging the gas remaining inside the pixel to the periphery when forming the light emitting layer by laser thermal transfer method. It is possible to reduce edge open defects that have already been transferred.

And a pixel defining layer having a first electrode formed on the substrate according to the present invention as described above, a groove and a passage through which the residual gas in the pixel region can be discharged, and a pixel defining layer formed on the first electrode. The organic light emitting display device may include an organic film layer having at least a light emitting layer on the exposed first electrode region, and a second electrode formed on the organic layer, respectively, between the substrate and the first electrode. The semiconductor device may further include a thin film transistor including a semiconductor layer including a source / drain region and a channel region, a source / drain electrode connected to the source / drain region, and a gate electrode corresponding to the channel region.

The thin film transistor may be a top gate structure in which a semiconductor layer is formed on a substrate, and a gate electrode is formed on the semiconductor layer. On the contrary, a gate electrode is formed on the substrate, and an upper portion of the gate electrode is formed. It may be a bottom gate structure in which a semiconductor layer is formed.

In addition, the semiconductor layer may be a polycrystalline silicon layer in which an amorphous silicon layer or an amorphous silicon layer is crystallized by Excimer Laser Annealing (ELA), Sequential Lateral Solidification (SLS), Metal Induced Crystallization (MIC), or Metal Induced Lateral Crystallization (MILC). have.

The thin film transistor formed as described above may be used in an organic light emitting display device formed between the substrate and the first electrode to be connected to any one of the source / drain electrodes exposed through the via hole and the first electrode.

The present invention utilizes a laser thermal transfer method by forming a pixel definition layer having a passage connecting a pixel region and a groove using a half-tone mask by using a groove on the pixel definition layer generated due to via holes on the protective film. As a result, the gas remaining between the first electrode and the donor film is gradually condensed in the transfer direction during lamination of the donor film and remains in the pixel edge area, thereby reducing edge open defects caused by the untransferred transfer layer. By forming the pixel definition layer having passages at one time using the tone mask, the inconvenience of having to separately form the passages can be reduced, the process can be simplified, and damage to the substrate can be reduced.

Claims (9)

A substrate having a light emitting area and a non-light emitting area; A thin film transistor formed in the non-light emitting region and including a gate electrode and a source / drain electrode; A passivation layer having a via hole on the thin film transistor; A first electrode connected to any one of the source / drain electrodes through the via hole; A pixel defining layer disposed on the first electrode and including an opening to expose a portion of the first electrode, the pixel defining layer having a groove and a passage on the non-light emitting area; An organic layer divided by the pixel defining layer, the organic layer layer exposing a portion of the groove and the passage on the pixel defining layer and having at least a light emitting layer on the exposed first electrode region; And And a second electrode on the organic layer. The method of claim 1, The groove is an organic light emitting display device comprising a position which is vertically spaced apart from the upper portion of the via hole. The method of claim 2, And the groove has a depth of 30% to 90% of the pixel definition layer. The method of claim 1, The passage includes connecting the pixel and the groove. The method of claim 1, The passage is formed in an organic light emitting display device having a width within 30% of the entire length of the horizontal or vertical of the pixel area. The method of claim 1, The pixel definition layer is formed of an organic or inorganic layer having an insulating property. The method of claim 1, And a thickness of the pixel definition layer is 0.5 to 3.0 mu m. Providing a substrate, Forming a thin film transistor including a gate electrode on the substrate, Forming a protective film having a via hole on the thin film transistor, Forming a first electrode on the protective film, Defining a pixel on the first electrode by using the half-tone mask and forming a pixel defining layer having a groove and a passage, An organic film layer including an organic light emitting layer is formed on the first electrode exposed by the pixel definition film by using a laser thermal transfer method, A method of manufacturing an organic light emitting display device comprising forming a second electrode on the organic layer. The method of claim 8, And the pixel definition layer is formed of an organic or inorganic layer having an insulating property.

Images