KR20200029885A - Organic light emitting display device and method for manufacturing the same - Google Patents

Abstract

The present invention relates to an organic light emitting display device capable of minimizing the influence of leakage currents on adjacent pixels in an organic light emitting device, and a manufacturing method thereof and, more particularly, to an organic light emitting display device which has an inorganic partition wall in an upper part of a bank to reduce side leakage currents between sub-pixels through an organic common layer in a structure of the organic light emitting device, and increases the reliability of a product in low gradation, and a method for manufacturing the inorganic partition wall.

Description

ORGANIC LIGHT EMITTING DISPLAY DEVICE AND METHOD FOR MANUFACTURING THE SAME

The present invention relates to an organic light emitting display device, in particular, an organic light emitting device having a non-conductive inorganic film partition on an upper portion of the bank to reduce side leakage current through an organic common layer in an OLED device structure and to improve product reliability in low grayscale. It relates to a display device and a method for manufacturing the same.

As the information society develops, the demand for display devices for displaying images is increasing in various forms. Accordingly, recently, various display devices such as a liquid crystal display (LCD), a plasma display panel (PDP), and an organic light emitting display (OLED) have been used.

Among the display devices, the organic light emitting display device is a self-emission type, and has an excellent viewing angle, contrast ratio, and the like, compared to a liquid crystal display device (LCD), and requires a separate backlight. . In addition, the organic light emitting display device has the advantage of being capable of driving a DC low voltage, a fast response speed, and a low manufacturing cost.

The organic light emitting display device includes pixels each including an organic light emitting element and a bank partitioning pixels to define pixels. The bank may serve as a pixel defining layer. The organic light emitting device includes an anode electrode, a hole transporting layer, an organic light emitting layer, an electron transporting layer, and a cathode electrode. In this case, when a high potential voltage is applied to the anode electrode and a low potential voltage is applied to the cathode electrode, holes and electrons are respectively transferred to the organic light emitting layer through the hole transport layer and the electron transport layer, and are combined with each other in the organic light emitting layer to emit light.

The organic light emitting device may include red, green, and blue organic light emitting devices that emit red, green, and blue light, or may include only white organic light emitting devices that emit white light. When the organic light emitting device includes a white organic light emitting device, the organic light emitting layer and the cathode electrode may be commonly formed in all pixels. That is, the organic light emitting layers are connected between adjacent pixels, and the cathode electrode formed next is also connected to each other between adjacent pixels.

In addition, the organic light emitting display device is formed by dividing the sub-pixels into red (R), green (G), and blue (B) sub-pixels for color display, and dividing the sub-pixels into organic sub-pixels. A light emitting layer is formed. In general, the organic emission layer is a deposition method using a shadow mask (shadow mask) was used. However, in the case of a large area, in the case of a large area, the sagging phenomenon occurs due to the load, and as a result, the yield decreases when used multiple times, so organic common layers other than the light emitting layer are formed in common in each sub-pixel without a shadow mask. have. However, current flows to the side through a common layer having a high conductivity that is continuously planar among the common layers commonly provided in the sub-pixels, thereby causing a side leakage current.

This side leakage current is generated particularly clearly seen in the low gray level region, and the side leakage current flowing horizontally from the blue sub-pixel flows through the common organic common layers common to the sub-pixels R, G, and B. At this time, the adjacent red sub-pixel R in the off state can be turned on to emit light. In this case, there is a problem of deterioration in color purity, and it may be difficult to express the gradation of pure blue.

This is because the driving voltage required for the red lighting is relatively lower than the driving voltage required for the blue lighting, and thus has a similar lighting effect even with a weak leakage current.

Particularly, due to the lighting phenomenon of the adjacent sub-pixel due to the side leakage current, a mixed color may occur in a low gray level expression, and a gray level display of a desired color may not be normally performed, which may cause image quality problems.

In addition, the greater the conductivity of the common organic common layer used as the common layer, the more the side leakage current may have more influence on adjacent sub-pixels.

The present invention provides an organic light emitting display device capable of minimizing the influence of adjacent pixels due to side leakage current through an organic light emitting layer in an organic light emitting device and a method for manufacturing the same.

An organic light emitting display device according to an exemplary embodiment of the present invention includes a first electrode disposed on a substrate, a bank covering an edge of the first electrode, an inorganic membrane partition formed on at least one of the upper surfaces of the bank, and the first electrode. It includes an electrode and an organic material stack disposed on the bank and a second electrode disposed on the organic material stack, wherein the first electrode, the organic material stack and the second electrode are sequentially stacked light emitting region The bank partitions the light emitting portion, and the inorganic film partition wall is disposed on the upper surface of the bank between the adjacent light emitting portions.

In addition, a method of manufacturing an organic light emitting display device according to an exemplary embodiment of the present invention includes preparing a substrate having a plurality of sub-pixels each having a light emitting unit and a non-light emitting unit surrounding the light emitting unit, and a light emitting unit of the plurality of sub pixels Each having a first electrode, a step of providing a bank in the non-light emitting portion, a step of providing an inorganic barrier rib in a predetermined region above the bank, a bank including the inorganic barrier rib, and an organic material in the light emitting unit The method may include depositing a stacked body and providing a second electrode on the stacked organic material.

The organic light emitting display device of the present invention and a method of manufacturing the same have the following effects.

First, the organic light emitting display device of the present invention is provided with a non-conductive inorganic membrane partition having a certain aspect ratio or more on the upper surface of the bank, and then depositing a common conductive organic layer, such as a hole injection layer and a hole transport layer, by the inorganic membrane partition It is possible to structurally separate the connection of the common organic layer that causes the side leakage current between adjacent sub-pixels.

Second, in an embodiment of the present invention, by forming a non-conductive inorganic film partition on the upper surface of the bank, the leakage current through the common organic layer may be blocked between neighboring light-emitting units to prevent image degradation due to color mixing.

Third, the embodiment of the present invention can minimize the influence of the conductivity characteristic of each material constituting the organic material common layer, thereby increasing the freedom of material selection when designing the organic material common layer.

Fourth, since the side leakage current can be prevented by the non-conductive inorganic membrane partition wall, the bank width can be reduced compared to the conventional method of preventing the side leakage current by increasing the bank width, which is advantageous for application to a high-resolution structure.

1A and 1B are plan and cross-sectional views, respectively, of an organic light emitting display device according to a first exemplary embodiment of the present invention.
2A to 2F are cross-sectional views illustrating a method of manufacturing an organic light emitting display device according to a first embodiment of the present invention
3A is a cross-sectional view of a photoresist pattern provided in a method of manufacturing an organic light emitting display device according to a first embodiment of the present invention
3B is a cross-sectional view of the inorganic barrier rib in the organic light emitting diode display according to the first exemplary embodiment of the present invention.
4A is a plan view showing an organic light emitting diode display according to a second embodiment of the present invention
Figure 4b is a cross-sectional view taken along line II 'of Figure 4a
5 is a plan view showing an organic light emitting diode display according to a third embodiment of the present invention
6 is a JV graph for comparative and experimental examples
7 is an electroluminescence (EL) spectrum graph for comparative and experimental examples

Advantages and features of the present invention, and methods for achieving them will be clarified with reference to embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only the present embodiments allow the disclosure of the present invention to be complete, and the ordinary knowledge in the technical field to which the present invention pertains. It is provided to fully inform the holder of the scope of the invention, and the invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for describing the embodiments of the present invention are exemplary and the present invention is not limited to the illustrated matters. The same reference numerals refer to the same components throughout the specification. In addition, in the description of the present invention, when it is determined that detailed descriptions of related known technologies may unnecessarily obscure the subject matter of the present invention, detailed descriptions thereof will be omitted.

When 'include', 'have', 'consist of' and the like mentioned in this specification are used, other parts may be added unless '~ man' is used. When a component is expressed as a singular number, the plural number is included unless otherwise specified.

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

In the case of the description of the positional relationship, for example, when the positional relationship of two parts is described as '~ top', '~ upper', '~ bottom', '~ side', etc., 'right' Alternatively, one or more other parts may be located between the two parts unless 'direct' is used.

In the case of a description of a time relationship, for example, 'after', 'following', '~ after', '~ before', etc., when the temporal sequential relationship is described, 'right' or 'direct' It may also include cases that are not continuous unless it is used.

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

"X-axis direction", "Y-axis direction" and "Z-axis direction" should not be interpreted only as a geometric relationship in which the relationship between each other is vertical, and is wider within a range in which the configuration of the present invention can function functionally. It can mean having directionality.

It should be understood that the term “at least one” includes all possible combinations from one or more related items. For example, the meaning of “at least one of the first item, the second item, and the third item” means 2 of the first item, the second item, or the third item, as well as the first item, the second item, and the third item, respectively. It can mean any combination of items that can be presented from more than one dog.

Each of the features of the various embodiments of the present invention may be partially or wholly combined or combined with each other, technically various interlocking and driving may be possible, and each of the embodiments may be independently performed with respect to each other or may be implemented together in an association relationship. It might be.

In this specification, the stack means a unit structure including a hole transport layer, an organic common layer including a hole transport layer and an electron transport layer, and an organic light emitting layer disposed between the hole transport layer and the electron transport layer. The organic common layer may further include a hole injection layer, an electron blocking layer, a hole blocking layer, and an electron injection layer, and other organic common layers may be further included depending on the structure or design of the organic light emitting device. In addition, it is defined as an organic layered product including both the organic common layer and the organic light emitting layer.

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

FIG. 1A is a plan view showing an organic light emitting diode display according to a first exemplary embodiment of the present invention, and FIG. 1B is a cross-sectional view on a horizontal line in the center of the red sub-pixel R and the blue sub-pixel B in FIG. 1A.

1A and 1B, the organic light emitting diode display according to the first exemplary embodiment of the present invention includes sub-pixels red (R), green (G), and blue (B) each having a light emitting unit and a non-light emitting unit surrounding the light emitting unit. A plurality of substrates 100, a first electrode 110 provided in each of the light emitting units of the plurality of sub-pixels, a bank 120 provided in the non-light emitting unit, and a predetermined portion of the top surface of the bank 123 The inorganic membrane partition wall 130 is provided, and the bank 120 including the inorganic membrane partition wall 130 and the hole injection layer 140, the hole transport layer 145, and the electron transport layer 180 provided in the light emitting unit It includes an organic common layer.

The shapes of the sub-pixels R, G, and B are arranged in a diamond shape, and the shape of the sub-pixels of the present invention is not limited to this, and can be variously changed within a range not departing from the spirit and scope of the present invention.

In addition, the light emitting unit includes organic light emitting layers 160 and 170 between the hole transport layer 145 and the electron transport layer 180, and a second electrode 190 is provided on the electron transport layer 180.

A residual organic common layer 185 may be provided between the upper surface of the inorganic membrane partition wall 130 and the second electrode 190, and the thickness of the remaining organic common layer 185 may be provided so as not to exceed 200 mm 2. . The remaining organic common layer 185 may include the same material as the organic layered product.

The substrate 100 may be a glass substrate or a flexible film.

The first electrode 110 is located under the bank 120 and may be formed on a part of the non-light emitting unit including a light emitting unit. That is, as illustrated, the bank 120 and the first electrode 110 may overlap, and the first electrode 110 is spaced between adjacent sub-pixels.

What distinguishes the light emitting unit from the non-light emitting unit is a bank 120, and an organic layered product is formed in a region where the bank 120 is open, and is defined as a light emitting unit of each sub-pixel (R, G, B). Then, light is emitted from the light-emitting layers 160 and 170 of the organic material stack provided in the light-emitting portion.

Substantially, the bank 120 is formed to a thickness of approximately 1 μm to 5 μm and is relatively higher than the total thickness of the organic material stacks provided between the first electrode 110 and the second electrode 190. Therefore, when the organic material is deposited by thermal ecapration, the step coverage is not excellent, so that the thickness of the organic layered product is relatively thin on the side surface 122 of the bank than the top surface 123 of the bank. Can be. However, in the recent organic light emitting display devices, an organic common layer is commonly deposited on all sub-pixels in order to increase process yield or in a tandem structure without separate regions, and at this time, an organic common layer is provided on all sub-pixels without a deposition mask. Although the thickness of the common layer is deposited and there is a difference in thickness, the organic common layer is also accumulated on the bank top surface 123 including the bank side surface 122 including the light emitting unit. And, as described above, the organic common layer having high conductivity among the organic common layers connected as a whole causes the side leakage current.

In the organic light emitting diode display according to the first embodiment of the present invention, the inorganic barrier rib 130 is provided on a part of the upper surface of the bank 123, so that the hole injection layer 140 or the hole transport layer 145 having high inter-pixel conductivity is formed. It is intended to separate. That is, the inorganic membrane partition wall 130 is characterized by having a partition wall made of an inorganic membrane material that is close to insulating (non-conductive), and the inorganic membrane partition wall material 130 includes at least SiOx, SixNy, TiOx, Al2O3, and ZrOx. It can contain one. It is preferable that the content of oxygen or nitrogen contained in the inorganic membrane partition wall 130 is adjusted to maintain insulation. And it may not be limited to the materials listed, and may be replaced with an insulating inorganic film. In addition, the inorganic film partition wall 130 may be formed of a single inorganic insulating film, or may be formed by mixing a plurality of insulating inorganic materials.

The width of the lower surface of the inorganic membrane partition wall 130 may be wider than the width of the upper surface of the inorganic membrane partition wall, and the width of the lower surface of the inorganic membrane partition wall contacting the upper surface of the bank may be 70 100 to 100 Å or less. In addition, the width of the inorganic membrane partition wall 130 may be provided to become narrower from the lower surface to the upper surface.

In addition, the height of the inorganic membrane partition wall 130 is greater than the height from the bank top surface 123 to the hole transport layer 145, and is equal to or less than the height from the bank top surface 123 to the second electrode 190. It can be provided. Therefore, the inorganic membrane partition wall 130 of the present invention described above may be formed in a structure having an aspect ratio of 15 to 30 level, which is a ratio of the height to the width of the inorganic membrane partition wall.

The inorganic membrane partition wall 130 may be provided close to vertical in the direction of the second electrode 190 based on the upper surface 1123 of the bank.

The organic evaporation layer is provided by thermal evaporation in a chamber maintained in a vacuum, and when the organic material sublimates to form a thin film on the substrate, the organic material is thermally evaporated compared to other thin film deposition methods. Does not have excellent step coverage.

Therefore, since the organic common layer and the organic light emitting layer materials are deposited on the side surfaces of the inorganic membrane partition 130, it is difficult to form a thin film, except that the residual organic material 185 is formed on a portion of the upper surface of the inorganic membrane partition wall as shown in FIG. 1B. The hole injection layer 140 having high conductivity or the hole transport layer 145 may be separated by interposing the inorganic membrane partition wall 130 between the sub-pixels R, G, and B.

The thickness of the organic common layer formed on the side surface of the inorganic film partition wall 130 based on the upper surface of the bank 123 may be thinned, and eventually the organic common layer may be separated between the sub-pixels R, G, and B. . Since the resistance of the organic common layer increases as the thickness of the organic common layer decreases, current leakage through the organic common layer decreases, and when the organic common layer is separated between sub-pixels, the leakage current may be close to zero.

In addition, in order to effectively implement separation of the hole injection layer 140 or the hole transport layer 145 having high conductivity between sub-pixels R, G, and B, the slope of the inorganic membrane partition wall 130 with respect to the bank top surface 123 is Preferably, it may be provided within a range of 60 ° to 90 °.

As shown in FIGS. 3A and 3B, the inorganic membrane partition wall 630 is formed according to the angle θ of the upper surface of the bank 620 and the side surface of the photoresist pattern 625 and the height of the photoresist pattern 625. A shading region may be formed on either side except the upper and lower surfaces of.

The shading region of the inorganic film partition wall 630 may more easily separate the high conductivity organic common layers included in the above-described organic material laminate with sub-pixels R, G, and B interposed therebetween.

In detail, it is possible to prevent the formation of a thin film because organic conductive layers having high conductivity are not deposited on the side surface of the inorganic film partition wall 630 corresponding to the shading region with low step coverage of the thermal evaporation method. This can significantly reduce the side leakage current through the organic common layers having high conductivity between the sub-pixels R, G, and B.

The reason for separating the hole injection layer 140 or the hole transport layer 145 in the organic light emitting diode display according to the first embodiment of the present invention is that the hole injection layer 140 is in direct contact with the first electrode (anode) 110 As a layer, a material having high hole conductivity, such as a p-type dopant, is used to reduce the barrier with the electrode in order to inject holes into the organic common layer in contact with the electrode, and these materials are a major cause of side leakage current. Because. In the case of the hole transport layer 145, since a material similar to the hole injection layer 140 can be used, side leakage current may be caused.

In some cases, in addition to the hole injection layer 140 and the hole transport layer 145, if the organic common layer having high conductivity is included between the first and second electrodes 110 and 190, the height of the inorganic membrane partition wall 130 By forming a higher than the height of the organic common layer having high conductivity, the organic common layer having high conductivity may be separated by interposing the inorganic film partition wall 130 between sub-pixels.

Therefore, the inorganic membrane partition wall 130 can selectively separate the organic common layer having high conductivity among organic common layers commonly provided between sub-pixels to remove side leakage current, thereby preventing a problem of image deterioration due to color mixing. .

A hole transport layer 145, a light emitting layer 160/170, and an electron transport layer 180 may be formed on the hole injection layer 140, in turn, as components of the organic material stack.

On the other hand, the auxiliary hole transport layer 150, such as a red sub-pixel, when the position of the light emitting layer 160 between the first and second electrodes 110, 190 according to the wavelength of the emission color, such an optical distance It is provided as an auxiliary to control, it has the characteristics of a hole transport layer.

An auxiliary hole transport layer may also be provided on the green sub-pixel not shown on the cross section of FIG. 1B. Depending on the wavelength, the required thickness of the auxiliary hole transport layer may be different, and in most cases, the thickness of the auxiliary hole transport layer is higher in a sub-pixel having a long wavelength light-emitting layer.

On the other hand, the structure of FIG. 1B shows an example in which the light emitting layers 160 and 170 are formed separately for each sub-pixel R, G, and B. However, in some cases, white may be used between the first and second electrodes 110 and 190. An organic material stack capable of emitting light is commonly provided in all sub-pixels, and color display can be achieved by applying red, green, and blue color filters for each sub-pixel. In addition, four sub-pixels including white, red, green, and blue may be provided as a unit pixel, and the inorganic membrane partition wall 130 may be provided between each sub-pixel to realize the above-described effect of the present invention. .

In the case of the blue sub-pixel B as shown in FIG. 1A, since the lifetime and efficiency are lower than that of the red and green sub-pixels R and G, the opening area may be designed to compensate for this disadvantage. In addition, the blue sub-pixel B has a higher driving voltage than the red and green sub-pixels R and G, and when driving the blue sub-pixel B in the low grayscale region, adjacent red sub-pixels R or green subs Since a leakage current may be generated in the pixel G region, at least an inorganic film partition wall 130 should be provided between the blue sub-pixel B and adjacent sub-pixels. Among the sub-pixels, an inorganic membrane partition wall 130 must be provided between the sub-pixel with the highest driving voltage and the sub-pixel with the lowest driving voltage.

A method of manufacturing the organic light emitting display device according to the first embodiment of the present invention will be described. 2A to 2F are process cross-sectional views illustrating a method of manufacturing an organic light emitting display device according to a first embodiment of the present invention.

2A, the first electrode 210 is formed on the substrate 200. The substrate 200 may be a glass substrate or a flexible substrate, and a thin film transistor array including a configuration of a driving thin film transistor, a switching thin film transistor, and a capacitor below each first electrode 210 before the first electrode 210 is formed. It may include. The thin film transistor array refers to the general structure of a known organic light emitting display device, and detailed description is omitted.

The first electrode 210 may be formed to be connected to one electrode of the driving thin film transistor. The first electrode 210 is a transparent metal material such as ITO, IZO (TCO, Transparent Conductive Material) or a layered structure of aluminum and titanium (Ti / Al / Ti), and a layered structure of aluminum and ITO (ITO / Al / ITO) ), APC alloys, and APC alloys and ITO stacked structures (ITO / APC / ITO) can be formed of high reflectivity metal materials. APC alloys are alloys of silver (Ag), palladium (Pd), and copper (Cu).

The first electrode 210 may be determined according to a work function and a light emission direction, and may be a single layer or multiple layers.

Then, the edge of the first electrode 210 of the adjacent sub-pixels is covered, and a bank 220 is formed. The area where the bank 220 is opened is defined as a light emitting unit, and the area where the bank 220 is located becomes a non-light emitting unit.

The bank 350 may be formed of an organic film such as an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin. .

Subsequently, a photoresist pattern 225 is formed on a portion of the top electrode 223 of the first electrode 210 and the non-light emitting portion of the light emitting portion. The photoresist pattern 225 is patterned using a photolithography method using a general photomask, and may be formed on the bank top surface 223 between sub-pixels.

When the thickness H of the photoresist pattern 225 is larger than the thickness of the organic material accumulation layer between the first electrode 110 and the second electrode 190 of FIG. 1B, the second electrode 190 is formed on the upper portion. The inorganic membrane partition 130 may protrude.

This is when the thin film of the second electrode 190 is formed by the thermal evaporation method having low step coverage on the protruding inorganic membrane partition 130, the second electrode 190 is As the deposition of the inorganic film partition wall 130 does not occur or is thin, the resistance of the second electrode 190 may increase or the current may not be injected and disconnection may occur. In addition, the adhesive property with the encapsulation layer may be weakened by the protruding inorganic membrane partition 130.

Therefore, the thickness of the photoresist pattern 225 may be provided in a condition that is larger than the first hole injection layer 140 having high conductivity and is smaller than the thickness of the organic laminate.

However, the second electrode 190 may be formed by physical vapor deposition, such as sputtering, having excellent step coverage characteristics. In this case, the thickness of the photoresist pattern 225 can be formed to be the same as the thickness of the organic material laminate.

Next, as shown in FIG. 2B, an insulating (non-conductive) inorganic film 228 is formed on the substrate 200 including the photoresist pattern 225.

The thickness of the insulating inorganic film 228 may be formed in a range not exceeding the thickness of the photoresist pattern 225. When the thickness of the photoresist pattern 225 is the same or thicker, the time for forming the target inorganic film partition wall becomes longer, which is performed in the ion milling process using argon ions (Ar +) described later. The photoresist pattern 225 may be etched to form an inorganic film barrier having a level lower than a desired thickness.

In addition, when forming the insulating inorganic film 228, which is significantly lower than the thickness of the photoresist pattern 225, it is difficult to form the height of the target inorganic film partition wall, so that the photoresist pattern 225 should be at least half thick. do.

Subsequently, as shown in FIGS. 2C to 2E, an inorganic membrane partition wall is formed on the side surface B of the photoresist pattern 225 by an ion milling method using argon ions (Ar +).

2C, 2D, secondary sputtering when exposed to argon ions (Ar +) by an ion milling method on the surface of the insulating inorganic film 228 formed on the bank top surface 223 and the first electrode 210 Through the deposition phenomenon, an insulating inorganic membrane partition wall 230 having a width of 100 mm or less and a high aspect ratio close to a designated photoresist pattern 225 height may be formed.

Particles of the insulating inorganic film 228 are protruded by the impact amount of argon ions (Ar +) and deposited on the side B of the photoresist pattern 225, and a thin film having a certain thickness can be formed according to the process time. When the width of the inorganic membrane partition wall 230 is more than 100 mm 2, it is removed by argon ions (Ar +), and the width of the final inorganic membrane partition wall 230 can maintain a maximum level of 100 mm 2. Therefore, the width of the inorganic membrane partition wall may be formed at a level of 70 Å to 100 ,, and the width of the lower surface of the inorganic membrane partition wall 230 may be formed wider than the width of the upper surface of the inorganic membrane partition wall 230. That is, the width of the upper surface of the inorganic membrane partition wall 230 may be from 70Å to less than 100Å.

2e and 2f, the insulating inorganic film 228 formed on the bank top surface 223 and the first electrode 210 was removed by an ion milling method using argon ions (Ar +). Thereafter, when the residual photoresist pattern 225 is removed by a solvent, the insulating inorganic membrane partition can be uniformly formed according to the shape of the side B of the photoresist pattern 225 at a level close to 100 mm width.

The solvent used at this time can be used by removing the photoresist pattern 225 and selecting a material that does not change the shape and structure of the bank 220.

3A and 3B relate to a method of optimizing the angle θ of an inclined surface formed between the top surface of the bank 620 and the side surface of the photoresist pattern 625 in the first embodiment of the present invention. By forming the shading region of the partition wall, the organic common layer having high conductivity between sub-pixels can be effectively separated. It is possible to control the angle θ of the inclined surface through exposure and development conditions for a positive photoresist or negative photoresist material through a general photolithography process.

Hereinafter, a method of forming an organic light emitting diode (OLED) including an organic material laminate after the process of FIGS. 2A to 2F will be described with reference to FIG. 1B.

After forming the inorganic membrane partition 130 on the substrate, a hole injection layer 140 and a hole transport layer 145 are formed on the substrate 100. The hole injection layer 140 and the hole transport layer 145 are partially formed on the inorganic membrane partition 130 and are included in the remaining organic common layer 185, and are not deposited on the side of the inorganic membrane partition 130. It may be formed in the form of particles in the form of islands.

Subsequently, an auxiliary hole transport layer 150 is selectively formed in a specific sub-pixel, followed by formation of light-emitting layers 160 and 170 corresponding to each sub-pixel, followed by commonly forming an electron transport layer 180, followed by The second electrode 190 is formed. An electron injection layer may be further provided between the electron transport layer 180 and the second electrode 190.

Here, the common organic material layer, the organic light emitting layer and the second electrode 190 included in the organic material laminate are formed by a thermal evaporation method, except for the auxiliary hole transport layer 150 and the light emitting layers 160 and 170. Sub-pixels without a mask may be commonly formed without region division.

Here, the light emitting layers 160 and 170 or the auxiliary hole transport layer 150 are formed by separating regions through a deposition mask, and are formed separately for each sub-pixel (R, G, B) and formed in correspondence with a light emitting unit, but are deposited. Since the mask is not attached to the substrate and the organic material is deposited in a vapor phase state, a state in which there is some intrusion in the process at the top of the bank 120 during the deposition process is not intended.

As described above, after forming the organic light emitting diode (OLED) first electrode 110, the organic material stack, and the second electrode 190 of the sub-pixels R, G, and B, each sub-pixel of the organic light emitting display device In (R, G, B), the hole injection layer 140 or the hole injection layer 140 and the hole transport layer 145, which are highly conductive by the inorganic membrane partition wall 130, are separated between sub-pixels, thereby preventing side leakage current. As a result, when a specific sub-pixel is turned on, a defect in which adjacent sub-pixels are turned on abnormally is not generated.

4A, a plan view showing an organic light emitting display device according to a second exemplary embodiment of the present invention, and FIG. 4B is a blue sub-pixel (B), a green sub-pixel (G), and a red sub-pixel on the line I to I 'in FIG. 4A. It is a sectional view of (R).

The shapes of the sub-pixels R, G, and B are arranged in a diamond shape, and the shape of the sub-pixels of the present invention is not limited to this, and can be variously changed within a range not departing from the spirit and scope of the present invention.

The second embodiment of the present invention is substantially the same as FIG. 1B, except that a white organic light emitting device structure without a mask is applied.

Referring to the description of FIG. 4B, a buffer film 301 is formed on one surface of the first substrate 300. The buffer layer 301 is formed on one surface of the first substrate 300 to protect thin film transistors (TFTs) and organic light emitting diodes (OLEDs) from moisture penetrating through the first substrate 300 which is vulnerable to moisture permeation. do. The buffer film may be formed of a plurality of inorganic films alternately stacked. For example, the buffer film may be formed of a multilayer film in which one or more inorganic films of silicon oxide film (SiOx), silicon nitride film (SiNx), and SiON are alternately stacked. The buffer film can be omitted.

A thin film transistor (TFT) is formed on the buffer film. The thin film transistor TFT includes an active layer 302, a gate electrode 304, a drain electrode 305, and a source electrode 306. The thin film transistor (TFT) in FIG. 4 illustrates that the gate electrode 304 is formed by an upper gate (top gate) method positioned on the active layer 302, but it is not limited thereto. . That is, thin film transistors (TFTs) have a lower gate (bottom gate, bottom gate) method in which the gate electrode 304 is positioned below the active layer 302, or the gate electrode 304 has upper and lower portions of the active layer 302. It may be formed by a double gate (double gate) method that is located in all.

The active layer 302 is formed on the buffer film. The active layer 302 may be formed of a silicon-based semiconductor material or an oxide-based semiconductor material. A light blocking layer for blocking external light entering the active layer 302 may be formed between the buffer layer and the active layer 302.

A gate insulating layer 303 may be formed on the active layer 304. The gate insulating film 303 may be formed of an inorganic film, for example, a silicon oxide film (SiOx), a silicon nitride film (SiNx), or multiple films thereof.

A gate electrode 304 and a gate line may be formed on the gate insulating layer 303. The gate electrode 304 and the gate line are any of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu). It may be formed of a single layer or multiple layers of one or alloys thereof.

An interlayer insulating layer 307 may be formed on the gate electrode 304 and the gate line. The interlayer insulating film 307 may be formed of an inorganic film, for example, a silicon oxide film (SiOx), a silicon nitride film (SiNx), or multiple films thereof.

A source electrode 306, a drain electrode 305, and a data line may be formed on the interlayer insulating layer 307. Each of the source electrode 306 and the drain electrode 305 may be connected to the active layer 302 through a contact hole passing through the gate insulating layer 303 and the interlayer insulating layer 307. The source electrode 306, the drain electrode 305, and the data lines are molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), and neodymium (Nd). And copper (Cu), or a single layer or multiple layers of alloys thereof.

A protective layer for insulating the thin film transistor TFT may be formed on the source electrode 306, the drain electrode 305, and the data line. The protective film may be formed of an inorganic film, for example, a silicon oxide film (SiOx), a silicon nitride film (SiNx), or multiple films thereof.

A planarization layer 308 may be formed on the interlayer insulating layer 307 or the protective layer to flatten the step due to the thin film transistor (TFT). The planarization film 308 may be formed of an organic film such as an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin. have.

An organic light emitting device (OLED) and a bank 350 are formed on the planarization layer 308. The organic light emitting diode OLED includes a first electrode 310, an organic light emitting layer 315, and a second electrode 320. The first electrode 310 may be an anode electrode, and the second electrode 320 may be a cathode electrode.

The first electrode 310 may be formed on the planarization layer 308. The first electrode 310 is connected to the source electrode 306 of the thin film transistor TFT through the passivation layer and the planarization layer 308 or the contact hole passing through the planarization layer 308.

The first electrode 310 is a transparent metal material such as ITO, IZO (TCO, Transparent Conductive Material) or a layered structure of aluminum and titanium (Ti / Al / Ti), and a layered structure of aluminum and ITO (ITO / Al / ITO) ), APC alloys, and APC alloys and ITO stacked structures (ITO / APC / ITO) can be formed of high reflectivity metal materials. APC alloys are alloys of silver (Ag), palladium (Pd), and copper (Cu).

The first electrode 310 may be determined according to a work function and a light emission direction, and may be a single layer or multiple layers.

The bank 350 may be formed to cover the edge of the first electrode 310 on the planarization layer 308 to partition the plurality of sub-pixels (BSP, GSP, RSP). That is, the bank 350 serves to define sub-pixels BSP, GSP, and RSP, and the sub-pixel corresponds to a light emitting unit. In addition, the region where the bank 350 is formed does not emit light, and thus corresponds to a non-light emitting portion.

The bank 350 may be formed of an organic film such as an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, or a polyimide resin. .

The first electrode 310 provided in each of the plurality of sub-pixels BSP, GSP, and RSP, the bank 350 provided in the non-light emitting portion, and the inorganic membrane partition provided in a predetermined portion of the upper surface 353 of the bank 340, a bank 350 including the inorganic film partition wall 340, and an organic material stack 315 provided in the light emitting unit are formed. The organic layered product 315 is an organic common layer commonly formed on sub-pixels BSP, GSP, and RSP, and may be a white organic light emitting device that emits white light. In this case, the organic material stack 315 may be formed of a tandem structure of two or more stacks including a first stack 1 and a second stack 2. Each of the stacks (stack 1 and stack 2) may include a hole transport layer (HTL), at least one organic light emitting layer (EML), and an electron transport layer (ETL).

Also, a charge generation layer CGL may be formed between the first stack 1 and the second stack 2. The charge generation layer (CGL) is formed on the n-type charge generation layer (n-CGL) and the n-type charge generation layer adjacent to the first stack (stack 1) and adjacent to the second stack (stack 2). It may include a p-type charge generation layer (p-CGL) located. The n-type charge generation layer injects electrons into the first stack, and the p-type charge generation layer injects holes into the second stack. The n-type charge generation layer may be made of an organic common layer doped with an alkali metal such as Li, Na, K, or Cs, or an alkaline earth metal such as Mg, Sr, Ba, or Ra. The p-type charge generation layer may be formed by doping a dopant in an organic material having hole transport capability.

The second electrode 320 is formed on the organic material stack 315. The second electrode 320 is a common layer formed in common with the light emitting units BSP, GSP, and RSP. The second electrode 320 is a transparent metal material (TCO, Transparent Conductive Material) such as ITO or IZO that can transmit light, or magnesium (Mg), silver (Ag), or magnesium (Mg) and silver (Ag) It may be formed of a semi-transmissive conductive material such as an alloy of. A capping layer 330 may be formed on the second electrode 320. In the case of a lower emission method in which light is emitted in the direction of the substrate 300 including the TFT, the second electrode may be provided as an opaque electrode.

The second electrode 320 may be formed by physical vapor deposition, such as sputtering. A film formed by a physical vapor deposition method such as sputtering has excellent step coverage characteristics.

An encapsulation film (not shown) may be formed on the capping layer 330. The encapsulation film serves to prevent oxygen or moisture from penetrating the organic layered product 315 and the second electrode 320. To this end, the encapsulation film may include at least one inorganic film and at least one organic film.

Color filters (not shown) and a black matrix (not shown) may be formed on one surface of the second substrate (not shown) facing the first substrate 111. The color filters may be disposed in regions corresponding to the sub-pixels (BSP, GSP, RSP). Each of the color filters may be formed of an organic film containing a predetermined pigment, such as a red pigment, a green pigment, and a blue pigment.

The black matrix can be disposed between color filters. Since the black matrix is formed in the non-light emitting portion, not the sub-pixels BSP, GSP, and RSP, the black matrix may be disposed to overlap the bank 350. The black matrix may be formed of an organic film containing black pigment.

As described above, the second embodiment of the present invention forms an inorganic layer partition wall 340 on a predetermined portion of the upper surface of the bank 353 to form an organic layer stack between neighboring sub-pixels (BSP, GSP, RSP). It is possible to prevent side current leakage through 315), thereby preventing poor color mixing.

5 relates to an embodiment in which a plurality of inorganic membrane partitions are formed, and can be applied to both the first and second embodiments of the present invention described above.

As shown in FIG. 5, the blue sub-pixel B including the first inorganic membrane partition 530a and the second inorganic membrane partition 530b and the green sub-pixel G including the third inorganic membrane partition 530c, It may be formed of a red sub-pixel R including the fourth inorganic film partition 530d. A plurality of inorganic membrane partitions 530a and 530b may be provided to selectively surround the blue sub-pixel B in order to effectively block side leakage current generated when driving the blue sub-pixel having a relatively high driving voltage.

6 is a graph showing the effect on the structures of FIGS. 1A and 1B which are the first embodiment of the present invention. As a result of measuring the driving voltage [V] for the current density [J], it can be seen that the current density value in the 2.0 to 3.0 [V] region generated by the leakage current decreases.

When the inorganic membrane partition wall 130 having the above-described structure is applied, the side leakage current may be blocked to eliminate the phenomenon that the adjacent sub-pixels R emit light in the low gradation region.

FIG. 7 shows the results of measurement of the emission spectrum (EL spectrum) in the region of 2.0 to 3.0 [V] generated by the side leakage current of FIG. 6. In the structure of the comparative example of FIGS. 1A and 1B, it can be confirmed that the emission spectrum peak in the region of about 630 nm of the red sub-pixel R generated by the side leakage current is generated.

However, in the embodiment structure of the present invention of FIGS. 1A and 1B, the emission spectrum peak in the region of about 630 nm of the red sub-pixel R is significantly reduced due to the blocking effect of the side leakage current of the inorganic membrane partition 130 structure described above. It can be confirmed.

The embodiments of the present invention have been described in more detail with reference to the accompanying drawings, but the present invention is not necessarily limited to these embodiments, and can be variously modified without departing from the technical spirit of the present invention. . Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain, 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 scope of protection of the present invention should be interpreted by the claims, and all technical spirits within the scope equivalent thereto should be interpreted as being included in the scope of the present invention.

100: substrate 110: first electrode
120: bank 122: bank side
123: Bank top 130: Inorganic bulkhead
140: hole injection layer 145: hole transport layer
150: auxiliary hole transport layer 160: red light emitting layer
170: blue light emitting layer 180: electron transport layer
185: residual organic common layer 190: second electrode

Claims (19)

A first electrode disposed on the substrate;
A bank covering the edge of the first electrode;
At least one inorganic barrier rib formed on the upper surface of the bank;
An organic material stack disposed on the first electrode and the bank; And
It includes a second electrode disposed on the organic laminate,
The first electrode, the organic material stack and the second electrode has a light emitting portion in a region sequentially stacked,
The bank partitions the light emitting unit,
The inorganic film partition wall is an organic light emitting display device, characterized in that disposed on the upper surface of the bank between the adjacent light emitting portion. According to claim 1,
The inorganic film partition wall is an organic light emitting display device, characterized in that in direct contact with the upper surface of the bank between the light emitting portion. According to claim 1,
An organic common display layer is provided between the upper surface of the partition wall of the inorganic layer and the second electrode, and the organic common layer includes at least one of the same material of the organic material stack. According to claim 3,
The organic layered product includes a hole injection layer, a hole transport layer, a light emitting layer, and an electron transport layer,
The hole injection layer, the hole transport layer and the electron transport layer are organic common layers provided in a plurality of sub-pixels. According to claim 3,
The organic layered product includes a first stack including a first hole injection layer, a first hole transport layer, a first emission layer, and a first electron transport layer.
A second stack including a second hole injection layer, a second hole transport layer, a second light emitting layer and a second electron transport layer, and
A charge generating layer between the first stack and the second stack,
The organic material stack is an organic light emitting display device which is a common layer commonly provided in a plurality of sub-pixels. The method of claim 4,
The height of the inorganic membrane partition wall is greater than the height from the top surface of the bank on which the inorganic membrane partition wall is not formed to the hole transport layer, and is less than or equal to the height from the top surface of the bank on which the inorganic membrane partition wall is not formed to the second electrode. Organic light emitting display device, characterized in that. The method of claim 5,
The height of the inorganic membrane partition wall is equal to or greater than the height from the top surface of the bank on which the inorganic membrane partition wall is not formed to the second hole transport layer, and the height from the top surface of the bank where the inorganic membrane partition wall is not formed to the second electrode. Organic light emitting display device characterized in that the same or smaller. The method of claim 4 or 5,
The inorganic film partition wall is an organic light emitting display device, characterized in that formed close to the vertical in the direction of the second electrode with respect to the upper surface of the bank. The method of claim 4 or 5,
The width of the inorganic film partition wall is an organic light emitting display device characterized in that the narrower from the lower surface to the upper surface. According to claim 1,
The inorganic film partition wall is an organic light emitting display device made of an insulating inorganic film. The method of claim 10,
The inorganic membrane partition wall is an organic light emitting display device, characterized in that it comprises at least one of SiOx, SixNy, TiOx, Al2O ₃ and ZrOx. The method of claim 4 or 5,
The plurality of sub-pixels is composed of pixels including a red sub-pixel, a green sub-pixel, and a blue sub-pixel, and the inorganic barrier rib includes at least a sub-pixel with the highest driving voltage and a sub with the lowest driving voltage within the pixel. An organic light emitting display device, characterized in that provided between the pixels. According to claim 1,
The width of the lower surface of the inorganic barrier rib in contact with the upper surface of the bank is 70 100 to 100 ,, and the width of the lower surface of the inorganic barrier rib is wider than the width of the upper surface of the inorganic barrier rib. Preparing a substrate having a plurality of sub-pixels each having a light emitting unit and a non-light emitting unit surrounding the light emitting unit;
Providing a first electrode in each of the light emitting portions of the plurality of sub-pixels;
Providing a bank in the non-light emitting portion;
Providing an inorganic membrane partition in a predetermined region above the bank;
Depositing an organic material stack on the bank including the inorganic membrane partition and the light emitting portion; And
A method of manufacturing an organic light emitting display device comprising the step of providing a second electrode on the organic layered product. The method of claim 14,
The step of providing an inorganic barrier rib in a predetermined region above the bank is
A first step of providing a photoresist pattern using a photo mask so that a first electrode in a predetermined region above the bank and a light emitting region adjacent to the predetermined region is exposed;
E-beam evaporation, thermal evaporation, or chemical vapor deposition (CVD) method on the light-emitting and non-light-emitting portions of the plurality of sub-pixels including the photoresist pattern In the second step having an inorganic film;
A third step of providing an inorganic film partition wall on the side surface of the photoresist pattern using an ion milling method on the inorganic film; And
And a fourth step of removing the photoresist pattern,
The inorganic film partition wall is in contact with the side of the photoresist pattern, the method of manufacturing an organic light emitting display device, characterized in that provided in a vertical direction relative to the upper surface of the bank. The method of claim 15,
The method of manufacturing an organic light emitting display device, characterized in that the thickness of the photoresist pattern in the first step is less than 100% of the thickness of the organic layered product. The method of claim 16,
The thickness of the inorganic film in the second step is provided in 50% or more and 100% or less of the thickness of the organic laminate,
The manufacturing method of the organic light emitting display device, characterized in that the inorganic film partition wall of the third step has a width of the lower surface from 70Å to 100Å. The method of claim 15,
The second step of the inorganic film is an insulating inorganic film, SiOx, SixNy, TiOx, Al2O ₃ , A method of manufacturing an organic light emitting display device comprising at least one of ZrOx. The method of claim 15,
The third step is
Using argon (Ar) ions, and removing the inorganic film in the horizontal direction by argon ion milling; And
Method of manufacturing an organic light emitting display device comprising the step of removing the residual photoresist pattern by a solvent (Solvent).

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