TW201607000A - Organic light-emitting display and method for forming the same - Google Patents

Abstract

An organic light-emitting display (OLED) is provided. The OLED includes a substrate and a plurality of first electrode layers on the substrate. An auxiliary electrode layer is on the substrate and has a sidewall. An insulating layer is on the first electrode layers and has at least one opening to expose at least a portion of the sidewall of the auxiliary electrode layer. A second electrode layer is on the insulating layer and is electrically connected to the auxiliary electrode layer. A method for forming an OLED is also provided.

Description

Organic light emitting display and method of manufacturing same

The present invention relates to a display device, and more particularly to an organic light emitting display (OLED) and a method of fabricating the same.

Due to its thin thickness, light weight, and low power consumption, flat panel display devices are widely used in electronic devices, such as laptop computers and personal digital assistants (PDAs), instead of cathode ray tube (CRT) display technology. Electronic books, projectors, and mobile phones. In general, the flat display device includes an active matrix liquid crystal display (AMLCD) device or an active matrix organic light-emitting display (AMOLED) device. Unlike the active array liquid crystal display device, the active array organic light emitting display device is a self-luminous type element using an organic material, which does not require a backlight module, thereby simplifying the process and further reducing the thickness of the flat display device. . Typically, the pixel structure of the active array organic light emitting display device includes a thin film transistor (TFT) array substrate and a plurality of organic light emitting diodes disposed thereon. Each of the organic light emitting diodes includes an upper electrode (cathode or anode), a lower electrode (anode or cathode), and an organic light emitting layer disposed between the two electrodes.

In an active array organic light emitting display device, an electrode contact via is generally disposed outside the display region (or referred to as an active region) and electrically connected to the upper electrode to transfer power to the display region. However, the voltage drop effect causes a difference in brightness between the central pixel region and the surrounding pixel region in the display region (i.e., poor brightness uniformity). Since the upper-emitting organic light-emitting display device generally has a transparent conductive oxide having a higher resistance than a general metal (for example, indium tin oxide (ITO), indium zinc oxide (IZO), etc.) as its upper electrode, the voltage drop effect is caused. Will be more obvious. Furthermore, for large-sized organic light-emitting displays, the problem of voltage drop and poor brightness uniformity is more serious.

In order to improve the voltage drop and the brightness uniformity, a plurality of auxiliary electrodes may be disposed in the display region to form an electrical connection with the upper electrode. However, in order to prevent the organic light-emitting layer from shielding the auxiliary electrode during deposition, the prior art requires the use of a precise metal mask in the deposition stage of the organic light-emitting layer. The above metal mask is not easy to manufacture and expensive. Furthermore, since a large-sized metal mask is liable to be bent at the time of use, it cannot be applied to a large-sized display device.

Therefore, there is a need for a novel organic light emitting display and a method of fabricating the same, with a view to solving or alleviating the above problems.

An embodiment of the present invention discloses an organic light emitting display comprising: a substrate; a plurality of first electrode layers on the substrate; an auxiliary electrode layer on the substrate and having a sidewall; and an insulating layer located at the first On the electrode layer, a second electrode layer is disposed on the insulating layer and electrically connected to the auxiliary electrode layer; wherein the insulating layer has at least one opening to expose at least a portion of the sidewall of the auxiliary electrode layer.

Another embodiment of the present invention discloses a method of fabricating an organic light emitting display, comprising: providing a substrate; forming a plurality of first electrode layers and an auxiliary electrode layer on the substrate, wherein the auxiliary electrode layer has a sidewall; Forming an insulating layer on the electrode layer; forming at least one opening in the insulating layer to expose at least a portion of the sidewall of the auxiliary electrode layer; and forming a second electrode layer on the insulating layer electrically connected to the auxiliary electrode layer.

The above and other objects, features and advantages of the present invention will become more <RTIgt;

100‧‧‧Substrate

101, 103‧‧‧ side wall

102‧‧‧metallization

104‧‧‧First electrode layer

106‧‧‧Auxiliary electrode layer

108‧‧‧Insulation

110‧‧‧ first opening

112‧‧‧ second opening

114‧‧‧Metal compounds

116‧‧‧Organic layer

118‧‧‧Second electrode layer

1A to 1D are schematic cross-sectional views showing a method of fabricating an organic light emitting display according to an embodiment of the present invention.

Fig. 2 is a plan view showing an organic light emitting display according to a first embodiment of the present invention.

Fig. 3 is a plan view showing an organic light emitting display according to a second embodiment of the present invention.

Hereinafter, an organic light emitting display and a method of manufacturing the same according to embodiments of the present invention will be described. However, the present invention is to be understood as being limited to the details of the present invention. Furthermore, In the drawings and the description of the embodiments of the present invention, the same reference numerals are used to refer to the same or similar parts.

Please refer to FIG. 1D. FIG. 1D is a schematic cross-sectional view of an organic light emitting display according to an embodiment of the invention. The organic light emitting display includes a substrate 100, a first electrode layer 104 and an auxiliary electrode layer 106 on the substrate 100, and a cover substrate 100, an insulating layer 108 on the first electrode layers, and a second electrode layer. The insulating layer is electrically connected to the auxiliary electrode layer, wherein the auxiliary electrode layer 106 has a sidewall 101, and the insulating layer 108 has at least one first opening 110 exposing at least a portion of the sidewall 101 of the auxiliary electrode layer 106. In the present embodiment, the substrate 100 has a plurality of first electrode layers 104 thereon, and the auxiliary electrode layer 106 corresponds to the one or more first electrode layers 104. Here, for the sake of simplicity, only a first electrode layer 104 is shown.

In this embodiment, the auxiliary electrode layer 106 and the first electrode layer 104 respectively include a first transparent conductive layer, a metal layer and a second transparent conductive layer (not shown) stacked in sequence, wherein the first and the first The two transparent conductive layers may include indium tin oxide (ITO), indium zinc oxide (IZO), or indium tin zinc oxide (ITZO), and the metal layer may include silver, a silver alloy, an aluminum alloy, or the like.

In the present embodiment, one or more metal compounds 114 are located on the sidewall 101 of the auxiliary electrode layer 106 exposed outside the insulating layer 108. Metal compound 114 can include a sulfide or an oxide. For example, the metal compound can be silver sulfide or silver oxide.

In the present embodiment, the insulating layer 108 has a second opening 112 corresponding to one of the first electrode layers 104 to expose the first electrode layer 104. Furthermore, an organic layer 116 is disposed on the insulating layer 108 and compliantly fills the first opening 110 and the second opening 112 such that the organic layer 116 contacts the first electrode layer 104 and the auxiliary electrode layer 106. In an embodiment, the organic layer 116 is a single layer structure, which may be a light emitting layer (emitting Layer, EML), hole injection layer (HIL), hole transport layer (HTL), electron injection layer (EIL), and electron transport layer (ETL) One of them. In another embodiment, the organic layer 116 may be a multilayer structure composed of a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer. In still another embodiment, the organic layer 116 may also be composed of a light emitting layer, a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer.

In this embodiment, a second electrode layer 118 is disposed on the organic layer 116 and fills the first opening 110 and the second opening 112. In the present embodiment, the second electrode layer 118 is a transparent material. For example, the second electrode layer 118 may include a thin metal such as MgAg alloy or Ag alloy, indium tin oxide (ITO), indium zinc oxide (IZO), or indium tin zinc oxide (ITZO). It should be noted that the second electrode layer 118 in the first opening 110 is electrically connected to the auxiliary electrode layer 106 through the metal compound 114.

1A-1D is a schematic cross-sectional view showing a method of fabricating an organic light emitting display according to an embodiment of the present invention. Referring to FIG. 1A, a substrate 100 is provided. The substrate 100 may be composed of glass, quartz or plastic. In this embodiment, a plurality of thin film transistors (not shown) are disposed above the substrate 100 for controlling different pixel structures of the organic light emitting display. Furthermore, the thin film transistor has at least one metallization layer thereon, which may include metal wires, an inter-layer dielectric (ILD), and a contact via. Here, for the sake of simplicity, only a flat metallization layer 102 is shown.

Next, a plurality of first electrode layers 104 and an auxiliary electrode layer 106 are formed on the substrate 100, wherein the auxiliary electrode layer 106 has a sidewall 101. Here, for the sake of simplicity, only a first electrode layer 104 is shown. First electrode layer 104 and auxiliary electricity The pole layer 106 can be formed by chemical vapor deposition (CVD), sputtering, or any suitable deposition technique. In an embodiment, the first electrode layer 104 and the auxiliary electrode layer 106 can be simultaneously formed by the same deposition step and patterning step. In another embodiment, the first electrode layer 104 and the auxiliary electrode layer 106 may be separately formed by different deposition steps. In this embodiment, the first electrode layer 104 and the auxiliary electrode layer 106 each include a first transparent conductive layer, a metal layer and a second transparent conductive layer (not shown) stacked in sequence. For example, the first transparent conductive layer and the second transparent conductive layer may be indium tin oxide (ITO), indium zinc oxide (IZO) or indium tin zinc oxide (ITZO), and the metal layer may be silver. Moreover, in this embodiment, a contact window (not shown) may be respectively formed under each of the first electrode layer 104 and the auxiliary electrode layer 106, thereby being electrically connected to the metallization layer 102 or the thin film transistor.

Referring to FIG. 1B and FIG. 2 simultaneously, FIG. 2 is a plan view schematically showing an organic light emitting display according to a first embodiment of the present invention, and FIG. 1B is a schematic cross-sectional view showing a line A-A' in FIG. An insulating layer 108 is formed on the first electrode layer to cover the first electrode layer 104 and the auxiliary electrode layer 106. The insulating layer 118 can be formed by a suitable deposition technique such as chemical vapor deposition, physical vapor deposition (PVD) or a wet process, and the insulating layer 118 can be made of an organic material (for example, a photoresist). Material) or other suitable insulating material. In the present embodiment, the insulating layer 108 is used as a pixel define layer (PDL) of an organic light emitting display, thereby defining different pixel regions of the organic light emitting display.

Next, a first opening 110 is formed in the insulating layer 108 by the developing and etching processes to expose at least a portion of the sidewall 101 of the auxiliary electrode layer 106, and is formed in the insulating layer 108 corresponding to the first electrode layer 104. A second opening 112 of one of the first openings 112 exposes the upper surface of the first electrode layer 104. It should be noted that the insulating layer 108 at this time The entire sidewall 103 of the first electrode layer 104 is still covered.

As shown in FIG. 2, in the first embodiment, the auxiliary electrode layer 106 corresponds to a first electrode layer 104, and the first opening 110 exposes the entire sidewall 101 of the auxiliary electrode layer 106. However, the position of the first opening 110 is not limited thereto. In other embodiments, the first opening 110 may also expose only a portion of the sidewall 101 of the auxiliary electrode layer 106 without exposing the entire sidewall 101.

Please refer to FIG. 1B and FIG. 3 simultaneously. FIG. 3 is a plan view of the organic light emitting display according to the second embodiment of the present invention, and FIG. 1B is a schematic cross-sectional view of the line A-A' in FIG. The second embodiment differs from the first embodiment in that the auxiliary electrode layer 106 corresponds to the plurality of first electrode layers 104, and the insulating layer 108 has a plurality of first openings 110 therein, respectively exposing a portion of the auxiliary electrode layer 106. Part of the side wall 101. It should be understood that although FIG. 3 illustrates that the auxiliary electrode layer 106 corresponds to the three first electrode layers 104, the present invention is not limited thereto. In other embodiments, the auxiliary electrode layer 106 may correspond to fewer or more first electrode layers 104, depending on design requirements. Moreover, the number and position of the first openings 110 may also vary according to design requirements, and are not limited to the state illustrated in FIG.

Referring to FIG. 1C, an annealing process is performed to form one or more metal compounds 114 on the exposed sidewalls 101 of the auxiliary electrode layer 106. In this embodiment, the annealing process can be performed in an atmosphere containing an oxygen atmosphere, and the annealing temperature can be between 110 and 350 °C. In the present embodiment, the metal compound 114 may be a sulfide or an oxide. For example, the metal compound 114 can be silver sulfide or silver oxide. It should be noted that since the entire sidewall 103 of the first electrode layer 104 is covered by the insulating layer 108 at this time, the metal compound 114 is formed only on the metal layer sidewall 101 exposed by the auxiliary electrode layer 106. In the present embodiment, the height of the metal compound 114 is between 1 μm and 3 μm. between.

Referring to FIG. 1D, an organic layer 116 is formed and compliantly filled into the first opening 110 and the second opening 112 such that the organic layer 116 contacts the first electrode layer 104 and the auxiliary electrode layer 106. The organic layer 116 can be formed by a suitable deposition technique, such as evaporation, and the organic layer 116 has a thickness of between 50 nm and 400 nm. In an embodiment, the organic layer 116 is a single layer structure, which may be one of a light emitting layer, a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer. In another embodiment, the organic layer 116 may be a multilayer structure composed of a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer. In still another embodiment, the organic layer 116 may also be composed of a light emitting layer, a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer. It should be noted that in the deposition stage of the organic layer 116, since the metal layer 114 cannot be completely covered due to the poor step coverage of the organic layer 116, the metal compound 114 may protrude outside the organic layer 116.

Next, a second electrode layer 118 is formed on the organic layer 116 by a suitable deposition technique, such as physical vapor deposition, and fills the first opening 110 and the second opening 112. In the present embodiment, the second electrode layer 118 may be a thin metal such as MgAg alloy or Ag alloy, or a transparent conductive material such as indium tin oxide (ITO), indium zinc oxide (IZO) or indium tin zinc oxide (ITZO). It should be noted that in the deposition phase of the second electrode layer 118, since a portion of the metal compound 114 protrudes beyond the organic layer 116, the second electrode layer 118 may thus contact the metal compound 114 and pass through the metal compound 114 and the auxiliary electrode layer 106. Electrical connection.

According to the above embodiment, even if an organic layer exists on the auxiliary electrode layer of the organic light emitting display, the second electrode layer can be electrically connected to the auxiliary electrode layer through the metal compound formed on the sidewall of the auxiliary electrode layer. In other words, in the manufacture of organic layers In this stage, it is not necessary to use a precision metal mask which is expensive and difficult to manufacture to shield the auxiliary electrode layer, which further simplifies the process and reduces the manufacturing cost.

Although the invention has been disclosed above in several preferred embodiments, it is not intended to limit the invention. Anyone skilled in the art can make any changes and refinements without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

100‧‧‧Substrate

101, 103‧‧‧ side wall

102‧‧‧metallization

104‧‧‧First electrode layer

106‧‧‧Auxiliary electrode layer

108‧‧‧Insulation

110‧‧‧ first opening

112‧‧‧ second opening

114‧‧‧Metal compounds

116‧‧‧Organic layer

118‧‧‧Second electrode layer

Claims (10)

An organic light emitting display comprising: a substrate; a plurality of first electrode layers on the substrate; an auxiliary electrode layer on the substrate and having a sidewall; an insulating layer on the first electrode layers; The second electrode layer is disposed on the insulating layer and electrically connected to the auxiliary electrode layer; wherein the insulating layer has at least one first opening exposing the sidewall of the auxiliary electrode layer. The organic light emitting display according to claim 1, further comprising a metal compound on the sidewall of the auxiliary electrode layer exposed. The organic light emitting display of claim 2, wherein the metal compound comprises a sulfide or an oxide. The organic light emitting display according to claim 2, wherein the second electrode layer is electrically connected to the auxiliary electrode layer through the metal compound. The organic light emitting display of claim 4, wherein the second electrode layer is a transparent material. The OLED display of claim 1, wherein the insulating layer has a second opening corresponding to one of the first electrode layers to expose the first electrode layer, and the organic light emitting display further An organic layer is disposed on the insulating layer and fills the first opening and the second opening. The organic light emitting display according to claim 6, wherein the organic layer is one of a light emitting layer, an electron transporting layer, an electron injecting layer, a hole transporting layer and a hole injecting layer or the above The combination. A method for manufacturing an organic light emitting display, comprising: providing a substrate; forming a plurality of first electrode layers and an auxiliary electrode layer on the substrate, wherein the auxiliary electrode layer has a sidewall; forming a first electrode layer An insulating layer; at least one first opening is formed in the insulating layer to expose at least a portion of the sidewall of the auxiliary electrode layer; and a second electrode layer is formed on the insulating layer to be electrically connected to the auxiliary electrode layer. The method for fabricating an organic light emitting display according to claim 8, further comprising performing an annealing process after forming the first opening to form a metal compound on the sidewall of the auxiliary electrode layer exposed. The method for fabricating an organic light emitting display according to claim 8, further comprising: forming a second opening corresponding to one of the first electrode layers in the insulating layer to expose the first electrode An upper surface of the layer; and an organic layer formed on the insulating layer to fill the first opening and the second opening.