KR102212987B1 - Organic light emitting diode display panel - Google Patents

Abstract

An organic light emitting display panel capable of minimizing the luminance imbalance of the organic light emitting display panel according to the sheet resistance of the luminance common electrode by forming an auxiliary electrode according to an exemplary embodiment on a black matrix and connecting it to a common electrode is provided. In the organic light emitting display panel according to an embodiment of the present invention, since the auxiliary electrode is formed on the black matrix, it is not necessary to occupy a separate space for forming the auxiliary electrode, so that the sheet resistance of the common electrode can be minimized while maximizing the aperture ratio.

Description

Organic light emitting display panel {ORGANIC LIGHT EMITTING DIODE DISPLAY PANEL}

The present invention relates to an organic light emitting display panel, and more particularly, to supply a uniform voltage by reducing the surface resistance of a cathode electrode used as a common electrode, thereby minimizing the brightness imbalance of an image by display position. It is to provide a light emitting display panel.

The organic light-emitting display panel is a self-emission type display device and, unlike a liquid crystal display (LCD), does not require a separate light source, and thus can be manufactured in a lightweight and thin form. In addition, organic light-emitting display panels are not only advantageous in terms of power consumption by low voltage driving, but also have excellent color realization, response speed, viewing angle, and contrast ratio (CR), and thus are being studied as a next-generation display.

An organic light-emitting display panel includes a plurality of pixels, each of which is a thin film transistor (TFT), a pixel electrode (anode) capable of supplying holes to the organic light-emitting layer, an organic light-emitting layer, and a common electrode (cathode). Etc.

Organic light-emitting display panels are largely divided into a passive matrix method and an active matrix method. In the passive matrix method, the gate line and the data line cross each other to form a matrix, so each pixel is driven. In order to do so, since the gate lines are sequentially driven according to time, in order to represent the required average luminance, an instantaneous luminance equal to the average luminance times the number of lines must be produced.

However, in the active matrix method, a thin film transistor, which is a switching element that turns on/off a pixel, is positioned for each sub pixel, and the first electrode connected to the thin film transistor is It is turned on/off in units of subpixels, and the second electrode facing the first electrode becomes a common electrode.

In addition, since the voltage applied to the pixel is charged in the storage capacitor (CST), power is applied until the next frame signal is applied, so that it continues for one screen regardless of the number of gate lines. And drive. Therefore, since the same luminance is displayed even when a low current is applied, an organic voltage light emitting device of an active matrix type is mainly used in recent years because it has advantages of low power consumption and large size.

Organic light emitting display panels are divided into top emission and bottom emission according to the emission method.

In the bottom emission method, the pixel electrode is made of a transparent conductive material or a metal material that can transmit light. It may be formed and used, and may include a driving device protective film that does not transmit light on the driving device to prevent deterioration due to light of the driving device.

As described above, since the lower light emission method has a problem of lowering the aperture ratio, the upper light emission method is mainly used in recent years.

In the case of the top emission method, a transparent conductive material or a metal material is used for the common electrode. In the case of a metal material, a thin thickness, for example, less than 100 Å is formed in order to have a semi-transmissive property.

In the case of such a common electrode, due to an increase in sheet resistance, a voltage may be lowered from one side of the display panel toward the center.

The problem of lowering the voltage of the common electrode affects the luminance uniformity of each location of the organic light emitting display panel.

In this way, in order to minimize the problem of lowering the voltage of the common electrode, auxiliary electrodes are provided on the panel, and a bank formed between a plurality of pixels and a reverse taper shape or an under cut structure between the banks Various techniques are used to compensate for the voltage difference between the common electrode by forming a structure and connecting the auxiliary electrode and the common electrode under the structure.

However, in the connection method using the reverse tapered shape of the common electrode and the auxiliary electrode, the structure connected under the reverse tapered shape has a limit of the connection area.

When the connection area between the auxiliary electrode and the common electrode is small, an overall luminance imbalance may occur in the display panel, and in order to increase the connection area, a problem of reducing the aperture ratio due to an increase in the size and number of structures occurs.

The present invention is to solve the above-described problems of an organic light-emitting display panel, and to provide an organic light-emitting display panel capable of improving luminance uniformity for each position within the panel by reducing the surface resistance of a common electrode.

A problem to be solved according to an exemplary embodiment of the present invention is to provide an organic light emitting display panel in which the aperture ratio is increased by minimizing an area for an auxiliary electrode.

A problem according to an embodiment of the present invention is to provide an organic light emitting display panel in which the surface resistance of the common electrode is minimized by increasing the connection area between the auxiliary electrode and the common electrode.

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

An organic light emitting display panel capable of minimizing the sheet resistance of a common electrode according to an embodiment of the present invention is provided. A bank layer and a pixel electrode connected to the driving device are formed on a first substrate including at least one driving device.

The first connection auxiliary part is formed on the bank layer, the organic light emitting layer and the common electrode are formed on the pixel electrode, and the common electrode is formed to cover the first connection auxiliary part formed on the bank layer.

Meanwhile, a black matrix is formed at a position facing the first substrate and facing the at least one color filter layer and the bank layer. An auxiliary electrode is formed on the black matrix and is connected to the common electrode to minimize the sheet resistance of the common electrode.

An organic light emitting display panel according to another embodiment of the present invention includes: a first substrate including at least one driving element; A bank layer formed on the first substrate and a pixel electrode connected to the driving element; A first connection aid formed on the pixel electrode; A second substrate comprising an organic emission layer formed on the pixel electrode and a common electrode formed on the organic emission layer and extending to cover the first connection auxiliary unit, and facing the first substrate and including a color filter and a black matrix Is provided.

The black matrix is formed of a conductive material and serves as an auxiliary electrode, and is connected to a common electrode formed on the first connection auxiliary unit to minimize sheet resistance of the common electrode.

Organic light-emitting display panel by minimizing the sheet resistance of the common electrode by providing a connection auxiliary part formed on the bank layer and an auxiliary electrode on the black matrix, and connecting the common electrode formed on the connection auxiliary part and the auxiliary electrode on the black matrix according to an embodiment of the present invention. There is an effect that the luminance of can be made uniform.

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

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

1 is a schematic cross-sectional view illustrating a connection relationship between an auxiliary electrode and a common electrode of an organic light emitting display panel according to an embodiment of the present invention.
2 is a schematic cross-sectional view for explaining a connection relationship between an auxiliary electrode including a connection auxiliary layer and a common electrode according to an embodiment of the present invention.
3 is a schematic cross-sectional view illustrating an organic light emitting diode display including a conductive black matrix according to an exemplary embodiment.
4 is a schematic cross-sectional view illustrating an organic light emitting display device in which a connection auxiliary layer is formed on a black matrix according to an exemplary embodiment of the present invention.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the 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 forms different from each other, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to those who have it, and the invention is only defined by the scope of the claims.

The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining 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 describing the present invention, when it is determined that a detailed description of related known technologies may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted. When'include','have','consists of' and the like mentioned in the specification are used, other parts may be added unless'only' is used. In the case of expressing the constituent elements in the singular, it includes the case of including the plural unless specifically stated otherwise.

In interpreting the constituent elements, it is interpreted as including an error range even if there is no explicit description.

In the case of a description of the positional relationship, for example, if the positional relationship of two parts is described as'upper','upper of','lower of','next to','right' Or, unless'direct' is used, one or more other parts may be located between the two parts.

First, second, etc. are used to describe various elements, but these elements 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 a second component within the technical idea of the present invention.

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

Hereinafter, various configurations of an organic light emitting display panel capable of minimizing the sheet resistance of the common electrode without affecting the aperture ratio by forming the auxiliary electrode according to an embodiment on the black matrix and connecting it to the common electrode will be described.

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

1 is a schematic cross-sectional view illustrating a connection relationship between an auxiliary electrode and a common electrode of an organic light emitting display panel according to an embodiment of the present invention.

Referring to FIG. 1, the organic light emitting display panel 100 includes a first substrate 110, a driving device 111, a passivation layer 112, a pixel electrode 120, a bank layer 130, and an organic light emitting layer. 140), a common electrode 150, a first connection auxiliary unit 160, a second substrate 170, a color filter 171, a black matrix 172, and an auxiliary electrode 180.

First, the first substrate 110 may include any one of glass, plastic, and metal. The first substrate 110 may be implemented as a flexible substrate that can be bent by including any one of the above materials.

Plastics usable as a material of the first substrate 110 are polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate (Polyethyelenen Napthalate; PEN). , Polyethyelene Terepthalate (PET), Polyphenylene Sulfide (PPS), Polyallylate, Polyimide, Polycarbonate (PC), Cellulose Triacetate (TAC), Cellulose Acetate It may be any one of propionate (Cellulose Acetate Propionate: CAP). In addition, a buffering layer for blocking penetration of impurity elements may be further provided on the first substrate 110. The buffer layer may be formed of, for example, a single layer or multiple layers of silicon nitride or silicon oxide.

The driving element 111 is formed on the first substrate 110. The driving element 111 is a thin film transistor and includes an oxide layer made of IGZO (Indium Gallium Zinc Oxide), ZTO (Zinc Tin Oxide), ZIO (Zinc Indium Oxide), etc. Can include.

A passivation layer 112 is formed on the driving element 111 to protect the organic light emitting layer 140 from moisture and oxygen and to protect the driving element 111.

The pixel electrode 120 and the bank layer 130 connected to the driving element 111 are formed on the passivation layer 112.

The pixel electrode 120 is formed of a metal material that reflects light in the case of a top emission method according to an emission method of the organic light emitting display panel 100, and a transparent conductive material is used in the case of a bottom emission method. Can be used.

Hereinafter, for convenience of description, it will be described based on the top emission method.

On the other hand, the bank layer 130 is an inorganic insulating material such as silicon nitride (SiNx), silicon oxide (SiOx), or polyacryl, polyimide, benzocyclobutene, or acrylic resin. ), such as an organic insulating material, or a combination thereof, but is not limited thereto.

A first connection assistant 160 is formed on the bank layer 130.

The first connection auxiliary unit 160 may be formed of the same material as the bank layer 130 and may be formed of the same material as a column spacer (not shown), but is not limited thereto.

The organic emission layer 140 is formed on the pixel electrode 120, and the organic emission layer 140 is formed to extend to cover the first connection auxiliary unit 160.

The organic light-emitting layer 140 is a hole injection layer (HIL), a hole transfer layer (HTL), an organic light-emitting layer, so that holes and electrons can be transported smoothly to form excitons. EL), electron transfer layer (ETL), electron injection layer (EIL), etc. may be sequentially stacked and included.

The common electrode 150 is formed on the organic emission layer 140. The common electrode 150 is formed of a material that transmits light to have a transmittance of 60% or more.

The common electrode 150 is a transparent conductive material, for example, a metal oxide such as ITO or IZO, a mixture of a metal and oxide such as ZnO:Al or SnO2:Sb, poly(3-methylthiophene), poly[3,4 -(Ethylene-1,2-dioxy)thiophene] (PEDT), polypyrrole, and may be made of a conductive polymer such as polyaniline, but is not limited thereto.

The common electrode 150 is formed on the organic emission layer 140 extending to cover the first connection auxiliary unit 160 and is electrically connected to the auxiliary electrode 180.

Meanwhile, a color filter 171 and a black matrix 172 are formed on the second substrate 170 facing the first substrate 110.

The auxiliary electrode 180 is formed on the black matrix 172.

The auxiliary electrode 180 may be formed of a metal-based material having a sheet resistance of 50 Ω/sq or less, such as Mo, Cu, Ag, Al, and a common electrode formed extending to cover the first connection auxiliary unit 160 ( 150) and formed to be able to connect.

The auxiliary electrode 180 and the common electrode 150 are connected to each other by irradiating a laser from the outside of the first substrate based on the organic light emitting display panel 100 to weld the auxiliary electrode 180 to the common electrode 150. You can connect it by connecting it.

Alternatively, a method of connecting the auxiliary electrode 180 to the common electrode 150 by welding the auxiliary electrode 180 by irradiating a laser from the outside of the second substrate based on the organic light emitting display panel 100 may be used.

Meanwhile, the first connection auxiliary unit 160 may include a material that expands by heat during laser irradiation.

For example, when welding the auxiliary electrode 180 and the common electrode 150 using a laser by forming the first connection auxiliary unit 160 including a binder, IR dye, crosslinker, plasticizer, etc., the first connection auxiliary unit 160 is It expands to allow a smoother connection.

2 is a schematic cross-sectional view for explaining a connection relationship between an auxiliary electrode including a connection auxiliary layer and a common electrode according to an embodiment of the present invention.

Referring to FIG. 2, the organic light emitting display panel 200 includes a first substrate 210, a driving element 211, a passivation layer 212, a pixel electrode 220, a bank layer 230, and an organic light emitting layer 240. , A common electrode 250, a first connection assistant 260, a second substrate 270, a color filter 271, a black matrix 272, an auxiliary electrode 280, and a second connection assistant 290 do.

Hereinafter, redundant descriptions will be omitted.

The second connection auxiliary part 290 formed between the auxiliary electrode 280 and the black matrix 272 is formed of a material whose volume is expanded by heat. For example, it may include a binder, an IR dye, a crosslinker, a plasticizer, etc., but is not limited thereto.

In the step of welding the bonding surface of the auxiliary electrode 280 to the common electrode 250 by irradiating a laser by bonding the common electrode 250 and the auxiliary electrode 280, the second connection auxiliary unit 290 is heated by heat. By expanding and applying pressure to the bonding surface of the auxiliary electrode 280 in the direction of the common electrode 250, the reliability of the connection between the common electrode 250 and the auxiliary electrode 280 can be further increased.

3 is a schematic cross-sectional view illustrating an organic light emitting diode display including a conductive black matrix according to an exemplary embodiment.

Referring to FIG. 3, the organic light emitting display panel 300 includes a first substrate 310, a driving device 311, a passivation layer 312, a pixel electrode 320, a bank layer 330, and an organic light emitting layer 340. , A common electrode 350, a first connection assistant 360, a second substrate 370, a color filter 371, and a conductive black matrix 380.

The conductive black matrix 380 is formed using an opaque conductive material in order to perform the role of the auxiliary electrode as well as the role of the black matrix.

The conductive black matrix 380 and the common electrode 350 can be connected by contact due to bonding of the two substrates, and the surface of the conductive black matrix 380 and the common electrode 350 are made by using a laser to further improve the electrical connection. You can connect by welding.

4 is a schematic cross-sectional view illustrating an organic light emitting display device in which a connection auxiliary layer is formed on a black matrix according to an embodiment of the present invention.

Referring to FIG. 4, the organic light emitting display panel 400 includes a first substrate 410, a driving element 411, a passivation layer 412, a pixel electrode 420, a bank layer 430, an organic light emitting layer 440, and A common electrode 450, a second substrate 470, a color filter 471, a black matrix 472, an auxiliary electrode 480, and a first connection auxiliary unit 460 are included.

The first connection auxiliary part 460 is formed on the black matrix 472 formed on the second substrate 470 and the auxiliary electrode 480 using a laser is welded to the common electrode 450.

1 to 4, the auxiliary electrode 480 is not formed on the first substrate 410 but is formed on the second substrate 470, thereby simplifying the manufacturing process of the organic light emitting display panel 400. , It is formed on the black matrix 472 to form the auxiliary electrode 480 without affecting the aperture ratio.

Although the embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention. . Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but to explain the technical idea, and the scope of the technical idea 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 limiting. The scope of protection of the present invention should be interpreted by the claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

100, 200, 300C, 400: organic light emitting display panel
111, 211, 311, 411: driving element
120, 220, 320, 420: pixel electrode
130, 230, 330, 430: bank layer
140, 240, 340, 440: organic light emitting layer
150, 250, 350, 450: common electrode
160, 260, 360, 460: first connection assistant
170, 270, 370, 470: second substrate
171, 271, 371, 471: color filter
172, 272, 472: Black Matrix
180, 280, 480: auxiliary electrode
380: conductive black matrix
290: second connection assistant

Claims (12)

A first substrate including at least one driving element;
A bank layer formed on the first substrate and a pixel electrode connected to the driving element;
A first connection aid formed on the bank layer;
An organic light emitting layer formed on the pixel electrode;
A common electrode formed on the organic emission layer and extending to cover the first connection auxiliary part;
A second substrate including a plurality of color filters facing the first substrate and a black matrix facing the bank layer; And
An auxiliary electrode formed on the black matrix, wherein the common electrode is connected in contact with the auxiliary electrode,
The organic light-emitting display panel, wherein the first connection assistant is formed of a material that expands upon laser irradiation. The method of claim 1,
The organic light-emitting display panel, wherein the organic light-emitting layer is formed to extend to cover the first connection auxiliary part. The method of claim 1,
The auxiliary electrode is welded to contact the common electrode to be connected. delete The method of claim 1,
The organic light-emitting display panel, further comprising a second connection auxiliary part between the black matrix and the auxiliary electrode. The method of claim 5,
The organic light-emitting display panel, wherein the second connection assistant is formed of a material that expands upon laser irradiation. A first substrate including at least one driving element;
A bank layer formed on the first substrate and a pixel electrode connected to the driving element;
A first connection aid formed on the bank layer;
An organic light emitting layer formed on the pixel electrode;
A common electrode formed on the organic light-emitting layer and extending to cover the first connection assistant; And
A second substrate comprising a plurality of color filters facing the first substrate and a black matrix facing the bank layer,
The black matrix is formed of a conductive material,
The common electrode is connected in contact with the black matrix,
The organic light-emitting display panel, wherein the first connection assistant is formed of a material that expands upon laser irradiation. The method of claim 7,
The organic light-emitting display panel, wherein the black matrix is welded and connected to the common electrode. delete A first substrate including at least one driving element;
A bank layer formed on the first substrate and a pixel electrode connected to the driving element;
An organic light emitting layer formed on the pixel electrode;
A common electrode formed on the organic emission layer and extending to cover the bank layer;
A second substrate including a plurality of color filters facing the first substrate and a black matrix facing the bank layer;
A first connection aid formed on the black matrix; And
Including an auxiliary electrode formed on the first connection auxiliary,
The common electrode is connected in contact with the auxiliary electrode,
The organic light-emitting display panel, wherein the first connection assistant is formed of a material that expands when laser irradiation. The method of claim 10,
The auxiliary electrode is welded to contact the common electrode to be connected.

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