CN108417738B - OLED device fabrication method - Google Patents

Abstract

The invention provides a manufacturing method of an OLED device. A cathode contact layer spaced apart from an anode layer is arranged on a substrate substrate, a cathode contact hole is arranged on the pixel definition layer corresponding to the upper part of the cathode contact layer, and an electron transport layer is arranged in the manufacturing process. The cathode layer is spaced from the cathode contact layer by extending from the pixel opening to the cathode contact hole. Before the normal operation of the device, in order to make electrical conduction between the cathode contact layer and the cathode layer, equal potentials are applied to the cathode layer and the anode layer. At the same time, a voltage less than the potential of the cathode layer is applied to the cathode contact layer, so that a potential difference is formed between the cathode contact layer and the cathode layer, and the electron transport layer is broken down and conducts electricity under the action of the electric field, so as to realize the cathode layer and the cathode layer. The electrical conduction of the contact layer, when the OLED device is in operation, the cathode contact hole layer can directly provide voltage and current compensation to the cathode layer, thereby preventing the uneven brightness problem caused by voltage drop in a large area of the OLED display panel.

Description

OLED device fabrication method

technical field

The present invention relates to the field of display technology, and in particular, to a manufacturing method of an OLED device.

Background technique

Organic Light Emitting Diodes (OLED) belongs to a new type of current-mode semiconductor light-emitting device, which is a kind of self-luminous technology by controlling the injection and recombination of carriers in the device to excite organic materials to emit light. Compared with passive luminescent liquid crystal displays (LCDs), self-luminous OLED displays have the advantages of fast response speed, high contrast ratio, wide viewing angle, etc., and easy to achieve flexible display. It is very likely to become the mainstream product of next-generation display technology.

Active-matrix organic light emitting diodes (AMOLEDs) have basically the same display principle as LCD panels, both by controlling the switching state of the thin film transistor (TFT) of each sub-pixel to achieve display. The difference between the two is: AMOLED display uses TFT to control the current on the OLED to change its luminous brightness; LCD display uses TFT to control the voltage loaded on both ends of the liquid crystal cell to adjust the transmittance of its backlight. Compared with the two, AMOLED displays have higher requirements on the driving current capability of TFT. OLED is very sensitive to its driving current, and weak current changes will affect its luminous intensity, so it is required that the TFT drive tube can continuously and stably provide operating current. This imposes strict requirements on the stability of the AMOLED driver circuit, which also improves the design goals of the AMOLED driver circuit.

At room temperature, the resistance of metal conductors is non-zero, and the current passing through the conductor will produce a certain voltage drop, which is called IR Drop. IR Drop on metal wires can cause potential differences at different locations from the input. On a large-area display panel, this IR Drop will cause differences in the currents on the OLEDs in different positions, resulting in uneven light emission of the panel and display quality of images and images.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a manufacturing method of an OLED device, which can effectively prevent the IR Drop of the OLED device, thereby improving the uneven brightness of the OLED display panel.

In order to achieve the above purpose, the present invention provides a method for manufacturing an OLED device, comprising the following steps:

Step S1, providing a base substrate, and forming a spaced anode layer and a cathode contact layer on the base substrate;

Step S2, forming a pixel definition layer on the base substrate, the anode layer and the cathode contact layer, the pixel definition layer enclosing a pixel opening on the anode layer and correspondingly provided with a cathode contact hole above the cathode contact layer;

Step S3, forming a hole injection layer, a hole transport layer, a light emitting layer and an electron transport layer in sequence on the anode layer from bottom to top, the electron transport layer extends from the pixel opening to the cathode contact hole and is connected to the cathode contact hole. the cathode contact layers are in contact;

Step S4, forming a cathode layer on the electron transport layer, the cathode layer covering the cathode contact layer, and the electron transport layer separating the cathode layer from the cathode contact layer;

Step S5, applying a voltage of equal potential to the anode layer and the cathode layer, and simultaneously applying a voltage with a potential smaller than the potential of the cathode layer to the cathode contact layer, so that a potential difference is formed between the cathode contact layer and the cathode layer, and the electron transport layer is in the electric field. It is broken down and conducts electricity under the action of the action, so that the cathode layer and the cathode contact layer are electrically connected.

In the step S5, the potential difference formed between the cathode contact layer and the cathode layer is 10V-30V.

In the step S5, the state in which the cathode contact layer and the cathode layer have a potential difference is maintained for 5 minutes to 30 minutes.

In the step S5, the voltage applied to the anode layer and the cathode layer is 10V-30V, and the voltage applied to the cathode contact layer is -20V-20V.

In the step S3, the electron transport layer is formed from an evaporation material by an evaporation method.

In the step S3, the hole injection layer, the hole transport layer and the light emitting layer are respectively formed by vapor deposition method or inkjet printing method.

The material of the anode layer and the cathode contact layer is a hydrophilic conductive material, and the material of the pixel definition layer is a hydrophobic material.

In the step S3, the hole injection layer, the hole transport layer and the light emitting layer are formed in the pixel opening.

The cathode contact layer is simultaneously separated from the anode layer, the hole injection layer, the hole transport layer and the light emitting layer through the pixel definition layer.

In the step S1, the anode layer and the cathode contact layer are separated by 10 μm-20 μm.

Beneficial effects of the present invention: The present invention provides a method for manufacturing an OLED device, wherein a cathode contact layer spaced apart from the anode layer is arranged on the base substrate, and a cathode contact hole is arranged on the pixel definition layer corresponding to the upper part of the cathode contact layer During the production process, the electron transport layer extends from the pixel opening to the cathode contact hole to separate the cathode layer from the cathode contact layer. Before the device works normally, in order to make electrical conduction between the cathode contact layer and the cathode layer, the cathode A positive voltage of equal potential is applied to the layer and the anode layer, and a voltage less than the potential of the cathode layer is applied to the cathode contact layer, so that a potential difference is formed between the cathode contact layer and the cathode layer, and the electron transport layer is broken down under the action of the electric field and conducts electricity , so as to realize the electrical conduction between the cathode layer and the cathode contact layer. When the OLED device is working, the cathode contact hole layer can directly provide voltage and current compensation to the cathode layer, thereby preventing the OLED display panel from appearing in a large area. The uneven brightness caused by IR Drop question.

In order to further understand the features and technical content of the present invention, please refer to the following detailed description of the present invention and the accompanying drawings, however, the accompanying drawings are only for reference and illustration, and are not intended to limit the present invention.

Description of drawings

The technical solutions and other beneficial effects of the present invention will be apparent through the detailed description of the specific embodiments of the present invention with reference to the accompanying drawings.

In the attached drawing,

FIG. 1 is a flow chart of the manufacturing method of the OLED device of the present invention;

FIG. 2 is a schematic diagram of step 1 of the manufacturing method of the OLED device of the present invention;

FIG. 3 is a schematic diagram of step 2 of the manufacturing method of the OLED device of the present invention;

FIG. 4 is a schematic diagram of step 3 of the manufacturing method of the OLED device of the present invention;

FIG. 5 is a schematic diagram of step 4 of the manufacturing method of the OLED device of the present invention;

FIG. 6 is a schematic diagram of step 5 of the manufacturing method of the OLED device of the present invention.

Detailed ways

In order to further illustrate the technical means adopted by the present invention and its effects, a detailed description is given below in conjunction with the preferred embodiments of the present invention and the accompanying drawings.

Referring to FIG. 1, the present invention provides a method for fabricating an OLED device, comprising the following steps:

Step S1 , as shown in FIG. 2 , a base substrate 10 is provided, and a spaced anode layer 21 and a cathode contact layer 30 are formed on the base substrate 10 .

Specifically, the base substrate 10 is a glass substrate.

Specifically, in the step S1, the anode layer 21 and the cathode contact layer 30 are separated by 10 μm-20 μm, and are not connected to each other.

Specifically, the materials of the anode layer 21 and the cathode contact layer 30 are hydrophilic conductive materials.

Step S2 , as shown in FIG. 3 , a pixel definition layer 40 is formed on the base substrate 10 , the anode layer 21 and the cathode contact layer 30 , and the pixel definition layer 40 surrounds the pixel opening 41 on the anode layer 21 and is on the anode layer 21 . A cathode contact hole 45 is correspondingly provided above the cathode contact layer 30 .

Specifically, the material of the pixel definition layer 40 is a hydrophobic material.

Specifically, the cathode contact layer 30 is separated from the anode layer 21 by the pixel definition layer 40 .

Step S3, as shown in FIG. 4, forming a hole injection layer (Hole Inject Layer, HIL) 24, a hole transport layer (Hole Transport Layer, HTL) 25, an emitting layer (Emitting layer) on the anode layer 21 from bottom to top sequentially , EML) 26 and an electron transport layer (Electron Transport Layer, ETL) 27, the electron transport layer 27 extends from the pixel opening 41 to the cathode contact hole 45 and is in contact with the cathode contact layer 30.

Specifically, in the step S3, the electron transport layer 27 is formed from an evaporation material by an evaporation method. It should be noted that, in the actual application of the evaporation method to manufacture OLEDs, since the preparation of the independent electron transport layer 27 cannot be achieved technically, the cathode contact layer 30 cannot be directly connected to the cathode layer 23 subsequently, and the cathode contact hole layer 30 cannot be realized. Work.

Specifically, the electron transport layer 27 is disposed above the anode layer 21 and the cathode contact layer 30 , and is not separated by the pixel definition layer 40 , the electron transport layer 27 located in the pixel opening 41 and the electron transport layer 27 located in the cathode contact hole 45 The transport layer 27 is connected on the pixel definition layer 40 .

Specifically, in the step S3, the hole injection layer 24, the hole transport layer 25 and the light emitting layer 26 are formed in the pixel opening 41; the pixel definition layer 40 simultaneously connects the cathode contact layer 30 and the hole The injection layer 24, the hole transport layer 25, and the light emitting layer 26 are separated.

Specifically, in the step S3, the hole injection layer 24, the hole transport layer 25 and the light emitting layer 26 are formed by vapor deposition or ink-jet printing (IJP), respectively.

Step S4, as shown in FIG. 5, a cathode layer 23 is formed on the electron transport layer 27, the cathode layer 23 covers the cathode contact layer 30, and the electron transport layer 27 separates the cathode layer 23 from the cathode contact layer 30 .

Specifically, the cathode layer 23 is higher than the pixel definition layer 40 and is not separated by the pixel definition layer 40 , and the cathode layer 23 located above the pixel opening 41 and above the cathode contact hole 45 is connected above the pixel definition layer 40 , forming a whole surface structure.

Step S5, as shown in FIG. 6, apply the voltage in the range of equal potential to the anode layer 21 and the cathode layer 23 between 10V-30V, while the potential applied to the cathode contact layer 30 is smaller than the potential range of the cathode layer 23 at- The voltage of 20V-20V makes a potential difference of 10V-30V between the cathode contact layer 30 and the cathode layer 23 and keeps it for 5-30 minutes, the electron transport layer 27 is broken down under the action of the electric field and conducts electricity, thereby The cathode layer 23 and the cathode contact layer 30 are brought into electrical conduction.

The manufacturing method of the OLED device of the present invention includes disposing a cathode contact layer 30 spaced from the anode layer 21 on the base substrate 10, and disposing a cathode contact hole 45 on the pixel definition layer 40 corresponding to the cathode contact layer 30 above. The electron transport layer 27 extends from the pixel opening 41 to the cathode contact hole 45 to separate the cathode layer 23 from the cathode contact layer 30. Before the device operates normally, in order to make electrical conduction between the cathode contact layer 30 and the cathode layer 23 , a positive voltage of equal potential is applied to the cathode layer 23 and the anode layer 21, and a negative voltage less than the potential of the cathode layer 23 is applied to the cathode contact layer 30 at the same time, so that a potential difference is formed between the cathode contact layer 30 and the cathode layer, and the electron transport layer 27 Under the action of the electric field, it is broken down and conducts electricity, so as to realize the electrical conduction between the cathode layer 23 and the cathode contact layer 30, so that the fabricated OLED device is applied to the OLED display panel and during operation, a positive voltage is applied to the anode layer 21, and the cathode The same negative voltage is applied to the layer 23 and the cathode contact hole layer 30 respectively. The cathode contact hole layer 30 can directly provide voltage and current compensation to the cathode layer 23. Since the OLED device of each pixel is provided with the cathode contact layer 30 and the cathode layer 23 electrical conduction, which can prevent the uneven brightness caused by IRDrop in a large area of the OLED display panel.

To sum up, the present invention provides a method for manufacturing an OLED device, wherein a cathode contact layer spaced apart from an anode layer is arranged on a base substrate, and a cathode contact hole is arranged on the pixel definition layer corresponding to the upper part of the cathode contact layer, During the production process, the electron transport layer extends from the pixel opening to the cathode contact hole to separate the cathode layer from the cathode contact layer. Before the device works normally, in order to make electrical conduction between the cathode contact layer and the cathode layer, the cathode layer A positive voltage of equal potential is applied to the anode layer, and a voltage less than the potential of the cathode layer is applied to the cathode contact layer, so that a potential difference is formed between the cathode contact layer and the cathode layer, and the electron transport layer is broken down under the action of the electric field and conducts electricity. In this way, the electrical conduction between the cathode layer and the cathode contact layer is realized. When the OLED device is working, the cathode contact hole layer can directly provide voltage and current compensation to the cathode layer, thereby preventing the problem of uneven brightness caused by IR Drop in a large area of the OLED display panel. .

As mentioned above, for those of ordinary skill in the art, various other corresponding changes and deformations can be made according to the technical solutions and technical concepts of the present invention, and all these changes and deformations should belong to the protection scope of the claims of the present invention .

Claims (9)

1. A method for making an OLED device, comprising the following steps: Step S1, providing a base substrate (10), and forming a spaced anode layer (21) and a cathode contact layer (30) on the base substrate (10); Step S2, forming a pixel definition layer (40) on the base substrate (10), the anode layer (21) and the cathode contact layer (30), the pixel definition layer (40) surrounding the anode layer (21) A pixel opening (41) is provided and a cathode contact hole (45) is correspondingly provided above the cathode contact layer (30); Step S3, forming a hole injection layer (24), a hole transport layer (25), a light emitting layer (26) and an electron transport layer (27) on the anode layer (21) from bottom to top in sequence, and the electron transport layer (27) a layer (27) extending from the pixel opening (41) into the cathode contact hole (45) and in contact with the cathode contact layer (30); Step S4, a cathode layer (23) is formed on the electron transport layer (27), the cathode layer (23) covers the cathode contact layer (30), and the electron transport layer (27) connects the cathode layer (23) with the cathode contact layer (30). the cathode contact layers (30) are spaced apart; Step S5, applying a voltage of equal potential to the anode layer (21) and the cathode layer (23), and simultaneously applying a voltage with a potential smaller than the potential of the cathode layer (23) to the cathode contact layer (30), so that the cathode contact layer (30) A potential difference is formed between the cathode layer (23), the electron transport layer (27) is broken down under the action of the electric field and conducts electricity, so that the cathode layer (23) and the cathode contact layer (30) are electrically connected; In the step S3, the electron transport layer (27) is formed from an evaporation material by an evaporation method. 2 . The method for manufacturing an OLED device according to claim 1 , wherein, in the step S5 , the potential difference formed between the cathode contact layer ( 30 ) and the cathode layer ( 23 ) is 10V-30V. 3 . 3 . The method for manufacturing an OLED device according to claim 2 , wherein in the step S5 , the cathode contact layer ( 30 ) and the cathode layer ( 23 ) are kept in a state in which a potential difference exists for 5 minutes to 30 minutes. 4 . 4. The method for manufacturing an OLED device according to claim 2, wherein in the step S5, the voltage applied to the anode layer (21) and the cathode layer (23) is 10V-30V, and the voltage applied to the anode layer (21) and the cathode layer (23) is 10V-30V. The voltage applied to the cathode contact layer (30) is -20V-20V. 5. The method for manufacturing an OLED device according to claim 1, wherein in the step S3, the hole injection layer (24), the hole transport layer (25) and the light emitting layer (26) are respectively made of It is formed by evaporation method or inkjet printing method. 6. The method for manufacturing an OLED device according to claim 1, wherein the anode layer (21) and the cathode contact layer (30) are made of hydrophilic conductive materials, and the pixel definition layer (40) is made of a hydrophilic conductive material. ) is a hydrophobic material. 7. The method for manufacturing an OLED device according to claim 1, wherein in the step S3, the hole injection layer (24), the hole transport layer (25) and the light emitting layer (26) are formed on inside the pixel opening (41). 8. The method for manufacturing an OLED device according to claim 1, wherein the cathode contact layer (30) is simultaneously connected to the anode layer (21), the hole injection layer (24), the anode layer (21), the hole injection layer (24), The hole transport layer (25) and the light emitting layer (26) are separated. 9 . The method for manufacturing an OLED device according to claim 1 , wherein, in the step S1 , the anode layer ( 21 ) and the cathode contact layer ( 30 ) are separated by 10 μm-20 μm. 10 .