CN100429782C - Organic light emitting display device and method of manufacturing the same - Google Patents

Abstract

An organic light-emitting display device (OLED) includes a substrate and a plurality of organic light-emitting display units. The organic light-emitting display unit includes a thin film transistor, an anode, an organic light-emitting structure, a cathode and a bus line. The thin film transistor is arranged on the substrate. The anode is arranged on the thin film transistor and the substrate. The organic light-emitting structure is arranged on the anode. The cathode is arranged on the organic light-emitting structure. The bus line is electrically connected to the cathode to reduce the resistance value of the cathode.

Description

Organic light emitting display device and manufacturing method thereof

【Technical field】

The present invention relates to a display device, and in particular to an organic light emitting display device.

【Background technique】

In recent years, organic light-emitting display (OLED) has gradually attracted attention in the display market due to its simple structure, excellent operating temperature and response speed, sharp color contrast, and no viewing angle limitation.

Please refer to FIG. 1 , which shows a schematic view of a conventional bottom-emission organic light-emitting display device. A bottom emission organic light emitting display device 10 includes a substrate 11 , a thin film transistor 12 , a protective layer 13 , an anode 15 , an organic light emitting layer 16 , a cathode 17 and a spacer 18 . The anode 15 is a transparent indium tin oxide electrode, and the substrate 11 is also a transparent glass substrate. In the bottom emission organic light emitting display device 10 , the light generated by the light emitting layer 15 (shown by arrow a) passes through the anode 15 and the substrate 11 to be displayed on the screen. Due to the limitation of the light emitting direction, the light needs to pass through the substrate 11 configured with multiple modules, so that the aperture ratio of the bottom emission organic light emitting display device is relatively low.

On the other hand, the main idea of a top emission organic light emitting display device is that the light does not need to pass through the substrate with multiple modules but passes through the cathode and the spacer, so as to greatly increase the aperture ratio.

However, cathode materials and manufacturing techniques suitable for top-emission organic light-emitting display devices have yet to be developed. In terms of work function, aluminum metal is the best match for the organic light-emitting layer, but the light transmittance of metal is not high. Once an extremely thin metal layer is used to increase light transmission, the thin metal layer has a high resistance value. Cathodes with high impedance values lead to serious voltage drop problems, which greatly affect the quality of the display.

【Content of invention】

In view of this, the object of the present invention is to provide an organic light emitting display device and a manufacturing method thereof. The organic light-emitting display unit of the present invention can effectively solve the voltage drop problem, and can improve display quality no matter it is used in top-emitting or bottom-emitting organic light-emitting display devices.

According to the purpose of the present invention, an organic light-emitting display device (Organic Light-Emitting Display, OLED) including a substrate and a plurality of organic light-emitting display units is proposed. The organic light emitting display unit includes: a thin film transistor, an anode, an organic light emitting structure, a cathode and a bus line. The thin film transistor is arranged on the substrate. The anode is arranged on the thin film transistor and the substrate. The organic light emitting structure is disposed on the anode. The cathode is disposed on the organic light emitting structure. The bus line is electrically connected to the cathode to reduce the resistance of the cathode.

According to the purpose of the present invention, a method for manufacturing an organic light-emitting display unit is proposed, comprising the steps of: providing a substrate; forming an anode on the substrate; forming an organic light-emitting structure on the anode; forming a cathode on the organic light-emitting structure; And forming a bus line on the cathode.

According to the purpose of the present invention, a method for manufacturing an organic light-emitting display unit is proposed, including the steps of: providing a substrate; forming a thin film transistor on the substrate; forming an anode on the substrate and the thin film transistor; forming a protective layer to cover On the anode; form a bus line on the protective layer, the bus line is located on the side of the anode; form an organic light-emitting structure on the protective layer; and form a cathode on the organic light-emitting structure, the cathode is electrically connected to the bus line.

【Description of drawings】

In order to make the above-mentioned purposes, features, and advantages of the present invention more obvious and understandable, the preferred embodiments are specifically cited below, and in conjunction with the attached drawings, the detailed description is as follows:

FIG. 1 shows a schematic diagram of a conventional bottom-emission organic light-emitting display device.

FIG. 2 is a side view of an organic light emitting display unit according to Embodiment 1 of the present invention.

FIG. 3 is a side view of an organic light emitting display unit according to Embodiment 2 of the present invention.

【Detailed ways】

The main concept of the present invention is to set a bus line electrically connected to the cathode to reduce the resistance of the cathode, solve the problem of voltage drop, and improve the display quality. In the following, a top-emission organic light-emitting display device is taken as an example for specific description, but these embodiments do not limit the protection scope of the present invention. Those skilled in the art can understand that the present invention can also be applied to bottom-emission organic light-emitting display devices or other related display devices.

The organic light-emitting display device (Organic Light-Emitting Display, OLED) of the present invention includes a substrate and a plurality of organic light-emitting display units. The organic light emitting display unit includes: a thin film transistor (Thin Film Transistor, TFT), an anode, an organic light emitting structure, a cathode, and a bus line. The thin film transistor is arranged on the substrate. The anode is arranged on the thin film transistor and the substrate. The organic light emitting structure is disposed on the anode. The organic light emitting structure at least includes an electron transport layer (Electron Transport Layer, ETL), an organic light emitting layer (Electroluminescent Layer, EL) and a hole transport layer (Hole Injection Layer HTL). The cathode is disposed on the organic light emitting structure. The bus line is electrically connected to the cathode to reduce the resistance of the cathode.

Embodiment one

Please refer to FIG. 2 , which shows a side view of an organic light emitting display unit according to Embodiment 1 of the present invention. In the organic light emitting display unit 100, a reflective layer 111 is formed on the substrate 110, the thin film transistor 120 is disposed on the reflective layer 111; the anode 130 is disposed on the thin film transistor 120 and the substrate 110; the organic light emitting structure 140 is disposed on the anode 130; 150 is disposed on the organic light emitting structure 140 ; the bus line 160 is formed on the cathode 150 and is electrically connected to the cathode 150 to reduce the resistance of the cathode 150 .

)，以利光线穿透。如此一来，有机发光结构140所产生的光系可自反射层111反射并穿透阴极。In the organic light-emitting display unit 100, the cathode 150 is made of a light-transmitting material, such as a layer of thin-film metal, a layer of indium tin oxide (ITO), or a layer of thin-film metal and at least one layer of indium. A combination of tin oxides. In addition, the thickness of the cathode is small, such as tens of angstroms (

) to facilitate light penetration. In this way, the light generated by the organic light emitting structure 140 can reflect from the reflective layer 111 and pass through the cathode.

In the OLED unit 100, the bus line 160 is a thick metal layer, for example, the thickness of the metal layer is between 1000 angstroms and 2 microns. In addition, the bus line 160 is made of low-resistance metal, such as a metal layer containing aluminum or silver.

In the organic light emitting display unit 100 , the thin film transistor 120 shields part of the reflective layer 111 to form a shielding area, and the bus line 160 is located in the shielding area and is disposed opposite to the thin film transistor 120 . In this way, although an opaque bus line 160 is formed above the cathode 150, the aperture ratio of the organic light emitting display unit 100 is not affected, and mutual interference of light sources between two organic light emitting display units can be avoided.

In the actual manufacturing process, the manufacturing method of the organic light emitting display unit 100 includes steps: providing a substrate 110; forming a reflective layer 111 on the substrate 110; forming a protective layer 112 on the reflective layer 111; forming a thin film transistor 120 on the protective layer 112 forming an anode 130 on the protective layer 121; forming an organic light-emitting structure 150 on the anode 130; forming a cathode 150 on the organic light-emitting structure 140; forming a bus line 160 on the cathode 150 and located above the thin film transistor 120.

Embodiment two

The components of the organic light emitting display unit of this embodiment are the same as those of the first embodiment, but the relative positions of formation are different, and the manufacturing process is also different. This embodiment will continue to use the component numbers of the first embodiment.

Please refer to FIG. 3 , which shows a side view of an organic light emitting display unit according to Embodiment 2 of the present invention. In the organic light emitting display unit 200 , a protective layer 231 is disposed between the anode 140 and the bus line 260 , so that the anode 140 is adjacent to the bus line 260 but is not electrically connected. In addition, the bus line 260 is disposed on the sides of the organic light emitting structure 140 and the cathode 150, and is located between two organic light emitting units to form a black matrix.

In an actual manufacturing process, the manufacturing method of the organic light emitting display unit 200 includes steps: firstly, a substrate 110 is provided, and a reflective layer 111 is formed on the substrate 110 . Then, a thin film transistor 120 is formed on the substrate 110 . Next, the anode 130 is formed on the thin film transistor 120 and the substrate 110 . Afterwards, a protective layer 231 is formed to cover the anode 130 . Next, the bus line 260 is formed on the protection layer 230 , the bus line 260 is located on the side of the anode 130 , but is separated from the anode 130 by the protection layer 231 , so it is not electrically connected. After the organic light emitting structure 140 is formed on the protective layer 231 , a cathode 150 is formed on the organic light emitting structure 140 , and the bus line 260 is electrically connected to the cathode 150 to reduce the resistance value.

The organic light-emitting display unit disclosed in the above-mentioned embodiments of the present invention uses the thin-film metal coordination bus line as the cathode, and has the advantages of high light transmittance, work function matching with the organic light-emitting structure, and low impedance. Because the bus line can effectively reduce the cathode impedance, the original material can be made thinner and the display brightness can be improved. Preferably, the cathode material is no longer limited to light-transmitting materials, and a metal with a higher degree of matching with the organic light-emitting structure but low light transmission can be selected. As long as the metal layer is made extremely thin, it has high light transmission. . Furthermore, using a cathode with a low impedance value and a better work function can effectively solve the voltage drop problem and greatly improve the quality of the display device. In addition, compared with the original manufacturing process, the manufacturing method described in the second embodiment only needs to add one procedure, that is to say, the manufacturing method described in this embodiment is cheap and easy to implement. On the other hand, the manufacturing method described in Embodiment 1 can save the usage of high-definition photomasks, and can further save the manufacturing cost and time.

In summary, although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Anyone skilled in this art can make various changes without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be defined according to the claims.

Claims (9)

1. An organic light-emitting display device (Organic Light-Emitting Display OLED), is provided with a plurality of organic luminescence display units, and each organic luminescence display unit comprises at least:

   One substrate (substrate);

   (Thin Film Transistor TFT), is arranged on this substrate one thin-film transistor;

   One anode (anode) is arranged on this thin-film transistor and this substrate;

   One organic light-emitting structure is arranged on this anode;

   One negative electrode (cathode) is arranged on this organic light-emitting structure; And

   One Bus Wire (bus line) electrically connects with this negative electrode, and this bus linear system is formed at the side of this organic light-emitting structure and this negative electrode, and between two adjacent organic light-emitting units, forms a black matrix" (black matrix).
2. 2. organic light-emitting display device according to claim 1 is characterized in that, this organic light-emitting structure comprises an electron transfer layer, an organic luminous layer and an electric hole transport layer at least.
3. 3. organic light-emitting display device according to claim 1 is characterized in that this negative electrode comprises a thin film metal layer.
4. 4. organic light-emitting display device according to claim 3 is characterized in that, this negative electrode more comprise an indium tin oxide layer (indium tin oxide, ITO).
5. 5. organic light-emitting display device according to claim 1 is characterized in that, the thickness of this Bus Wire system between 1000 dusts (

   

   ) and 2 microns (μ m) between.
6. 6. organic light-emitting display device according to claim 1 is characterized in that, this bus linear system is made up of the metal of low-resistance value.
7. 7. organic light-emitting display device according to claim 1 is characterized in that this Bus Wire contains aluminium.
8. 8. organic light-emitting display device according to claim 1, it is characterized in that, this organic luminescence display unit more comprises a reflector, these reflection series of strata are arranged between this thin-film transistor and this substrate, make spectrum that this organic light-emitting structure produced from this reflective layer reflects and penetrate this negative electrode, this organic light-emitting display device is organic display unit on a top luminous (top emission).
9. An organic light-emitting display device (Organic Light-Emitting Display OLED), is provided with a plurality of organic luminescence display units, and each organic luminescence display unit comprises at least:

   One substrate (substrate);

   (Thin Film Transistor TFT), is arranged on this substrate one thin-film transistor, and the reflector of this thin-film transistor shaded portions forms a shielded area, and this Bus Wire is arranged at this shielded area of this thin-film transistor relatively;

   One anode (anode) is arranged on this thin-film transistor and this substrate;

   One organic light-emitting structure is arranged on this anode;

   One negative electrode (cathode) is arranged on this organic light-emitting structure; And

   One Bus Wire (bus line) electrically connects with this negative electrode;

   One reflector, these reflection series of strata are arranged between this thin-film transistor and this substrate, make spectrum that this organic light-emitting structure produced from this reflective layer reflects and penetrate this negative electrode, this organic light-emitting display device is organic display unit on a top luminous (top emission).

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