CN1568102A - Method for repairing pixel defect of organic light-emitting element - Google Patents

Abstract

The invention provides a pixel defect repairing method of an organic light-emitting element, which is used for repairing the organic light-emitting element with a substantial short circuit phenomenon. The pixel defect repairing method of the organic light-emitting element comprises the following steps: an electrical testing step and an isolation layer forming step, wherein, in the electrical testing step, a current or a voltage is applied between the first electrode and the second electrode of the organic light-emitting element so as to form an open circuit at the substantial short circuit position of the organic light-emitting element; in the isolation layer forming step, an isolation layer is formed at the open circuit position of the organic light emitting element. The present invention also provides another embodiment of a pixel defect repairing method for an organic light emitting device, which is different from the pixel defect repairing method for an organic light emitting device described above in that the method further comprises an electrical property detecting step.

Description

Method for repairing pixel defect of organic light-emitting element

technical field

The present invention relates to a method for repairing pixel defects of organic light-emitting elements, in particular to a method for repairing pixel defects of organic light-emitting elements capable of repairing substantial short circuits.

Background technique

In the manufacturing process of the organic light-emitting device, the organic light-emitting device defines a conductive anode and an auxiliary anode through photolithography, and then carries out a coating step of organic materials and inorganic materials (cathode layer) in a vacuum chamber. Since moisture and oxygen will affect the lifetime of the organic light-emitting device, an encapsulation process is required after the coating step to avoid reducing the lifetime of the device.

Generally, during the manufacturing process, due to substrate defects or poor cleanliness of the manufacturing environment, organic light-emitting elements are prone to short-circuit problems, which makes the current only pass through the defects and cannot drive all pixels, which affects the luminous efficiency of the element and the image display effect. ; At the same time, when the organic light-emitting device is passively driven, not only a single pixel cannot emit light, but also the operation of the entire vertical or horizontal row of pixels will be affected.

As shown in FIG. 1 , in the prior art organic light-emitting device inspection method, after the organic light-emitting device is packaged ( S21 ), the quality of the entire finished product is tested by a panel test step ( S22 ). When the organic light-emitting element has a short circuit phenomenon, after the entire element has been tested by the panel, because the outer layer of the element has been packaged, it is impossible to repair individual pixel defects inside, and it is directly eliminated. In this way, the yield rate of the product will be reduced, and the manufacturing cost will also be increased.

In the spirit of active innovation, the inventor thought hard about a "method for repairing pixel defects of organic light-emitting devices" that could solve the above-mentioned problems, and finally completed the invention after several researches and experiments.

Contents of the invention

The object of the present invention is to provide a method for repairing pixel defects of an organic light-emitting element that increases product yield, improves reliability, and reduces manufacturing costs.

To achieve the above purpose, the present invention provides a method for repairing pixel defects of an organic light-emitting element, which is used for repairing an organic light-emitting element with a substantial short circuit phenomenon. The organic light-emitting element includes a first electrode, an organic light-emitting layer, and a second electrode on a substrate. electrode. The method for repairing pixel defects of an organic light-emitting element includes the following steps: an electrical test step and an insulating layer forming step, wherein, in the electrical test step, a current or voltage is applied between the first electrode and the second electrode of the organic light-emitting element, To form an open circuit at the substantially short circuit of the organic light-emitting element; in the step of forming the insulating layer, an insulating layer is formed at the open circuit of the organic light-emitting element. At the same time, the present invention also provides another embodiment of the above-mentioned method for repairing pixel defects of organic light-emitting devices, which is different from the above-mentioned method for repairing pixel defects of organic light-emitting devices in that the method further includes an electrical testing step; wherein, in the electrical testing In the step of detecting the short circuit degree of the organic light-emitting element in the electrical testing step, when the ratio of the detected short circuit divided by the open circuit is less than a certain value or the leakage current is lower than a certain value; in the subsequent insulating layer forming step , forming an insulating layer at the break.

Compared with the prior art, the present invention provides a method for repairing pixel defects of an organic light-emitting element. This method repairs an organic light-emitting element with a substantial short circuit, which can not only find out the short circuit before performing the packaging step, but also repair the defect at the same time. Short circuit, and then make it lose its conductive properties, so that the pixel with the original defect has the same light-emitting ability as the adjacent non-defective pixel, without directly eliminating the entire panel, and at the same time increases the yield and reliability of the product, and goes further The manufacturing cost of the product is reduced.

Description of drawings

FIG. 1 is a block diagram of a pixel defect detection method of an organic light-emitting element in the prior art.

FIG. 2 is a block diagram of a method for repairing a pixel defect of an organic light-emitting device according to this embodiment.

3a and 3b are schematic diagrams of the electrical testing steps of this embodiment.

FIG. 4a and FIG. 4b are schematic diagrams of a substantial short circuit of the organic light-emitting element of this embodiment.

Fig. 5a and Fig. 5b are schematic diagrams of the open circuit obtained after the electrical testing steps of this embodiment.

6a and 6b are schematic diagrams of the steps of forming the insulating layer in this embodiment.

FIG. 7 is a block diagram of a method for repairing a pixel defect of an organic light emitting device according to another embodiment of the present invention.

Explanation of symbols in the figure

1 organic light emitting element

11 first electrode

12 organic light-emitting layer

13 second electrode

2 insulation layer

3 Impurities

S01 Electrical test procedure

S02 Insulation layer formation step

S11 Electrical Test Procedure

S12 electrical testing steps

S13 Insulation layer forming step

S21 Packaging steps

S22 panel test procedure

Detailed ways

A method for repairing pixel defects of an organic light-emitting device according to an embodiment of the present invention will be described below with reference to related drawings, wherein the same components will be described with the same reference symbols.

For an organic light emitting device, it has pixels arranged in arrays, and in the embodiments of the present invention, for convenience of description, a pixel will be used to replace the entire pixel of the organic light emitting device.

The present invention provides a method for repairing pixel defects of an organic light-emitting element, which is used to repair an organic light-emitting element 1 with a substantial short circuit phenomenon. The organic light-emitting element 1 includes a first electrode 11, an organic light-emitting layer 12, and a second electrode on a substrate. The electrode 13, the method for repairing the pixel defect of the organic light-emitting element includes the following steps: an electrical testing step (S01) and an insulating layer forming step (S02), as shown in FIG. 2 .

Wherein, as shown in FIG. 3a and FIG. 3b, in the electrical testing step (S01), a current or voltage is applied between the first electrode 11 and the second electrode 13 of the organic light emitting element 1, so that the organic light emitting element 1 The substantially short-circuited part forms an open circuit due to the heat generated by passing current; in the insulating layer forming step ( S02 ), an insulating layer 2 is formed at the open circuit of the organic light-emitting element 1 .

In this embodiment, the first electrode 11 is a conductive metal oxide, and the conductive metal oxide can be indium tin oxide (ITO), indium zinc oxide (IZO) or aluminum zinc oxide (AZO).

In addition, the organic light-emitting layer 12 may include a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer. The small-molecule organic light-emitting layer 12 is formed by vapor deposition; 12 is formed by spin coating method, inkjet method or printing method. Among them, the main material of the hole injection layer is copper phthalocyanine (CuPc); the material of the hole transport layer is mainly 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB); The material of the layer is mainly lithium fluoride (LiF); the material of the electron transport layer is mainly tris(8-quinolinato-N1,08)-aluminum(Alq).

Next, the second electrode 13 is formed by vapor deposition or sputtering, and its material can be aluminum, aluminum/lithium, calcium, magnesium-silver alloy or silver.

Please refer to FIG. 3 a again. In the electrical testing step ( S01 ), a positive charge and a negative charge are respectively applied between the first electrode 11 and the second electrode 13 of the organic light emitting element 1 to form an open circuit at the substantially short circuit of the organic light emitting element 1 . In addition, a negative charge and a positive charge can also be applied between the first electrode 11 and the second electrode 13, respectively, as shown in FIG. 3b. The electrical test step (S01) is performed in a buffer chamber or a single chamber environment, the interior of which is vacuum, and can also be filled with an inert gas.

Wherein, the substantial short circuit refers to a real short circuit or a near short circuit. There are two main situations that cause the organic light-emitting element 1 to be substantially short-circuited: first, during the manufacturing process of the organic light-emitting element, impurities 3 (bubbles or particles) fall into the organic light-emitting element 1 due to insufficient cleanliness of the manufacturing environment; A substantial short circuit is caused, as shown in Figure 4a. Meanwhile, another situation is a substantial short circuit caused by the uneven surface of the first electrode 11 , as shown in FIG. 4 b .

5a and 5b are the open circuit conditions obtained after the organic light emitting element 1 in FIG. 4a and FIG. 4b undergoes the electrical test step ( S01 ). Since the coating surface of the substrate is mostly downward during the process steps of the organic light-emitting element, it can be seen from Fig. 5a and Fig. 5b that after the electrical test step (S01), the organic light-emitting layer 12 and the second electrode 13 will warp outward. In this case, if the insulating layer forming step (S02) is not performed in real time, in the following process steps, as long as the coated surface of the substrate has a chance to be turned upward, the second electrode 13 may contact the first electrode 11 again to form a short circuit phenomenon .

The insulating layer forming step ( S02 ) forms an insulating layer 2 at the disconnection of the organic light-emitting element 1 , and the insulating layer 2 partially penetrates into the organic light-emitting layer, as shown in FIG. 6 a and FIG. 6 b . The insulating layer forming step (S02) forms an insulating layer 2 at the disconnection by vacuum evaporation. Here, the material of the insulating layer 2 can be an organic material constituting the organic light-emitting layer 12, such as: a hole injection layer, a hole transport layer, etc. layer, light-emitting layer, electron transport layer, and electron injection layer, or inorganic materials with high resistance such as silicon nitride, silicon oxide, and silicon oxynitride. In addition, when combined with the passivation coating system, high-resistance polymers can be used as the insulating layer 2 material, such as fluorinated resin, Parylene, etc.

The insulating layer forming step (S02) may also be oxidizing the second electrode 13 in an oxygen-containing atmosphere free of moisture to form an oxide layer on the surface of the second electrode 13 to isolate the second electrode 13 from the first electrode 11 , so as to achieve the effect of maintaining an open circuit.

FIG. 7 shows another embodiment of the method for repairing pixel defects of an organic light-emitting element of the present invention. As shown in FIG. 7 , the method for repairing pixel defects of an organic light-emitting device according to the present invention includes an electrical testing step ( S11 ), an electrical testing step ( S12 ) and an insulating layer forming step ( S13 ). Wherein, except for the electrical property testing step ( S12 ) and the insulating layer forming step ( S13 ), other components and features are the same as those of the first embodiment.

Here, the electrical testing step (S12) detects the degree of short circuit of the organic light-emitting element 1 in the electrical testing step (S11); in the insulating layer forming step (S13), when the short circuit detected in the electrical testing step (S12) The degree is less than a certain value, that is, when the ratio of the short circuit divided by the open circuit is less than a certain value or the leakage current is lower than a certain value, an insulating layer 2 is formed at the open circuit. Because when a constant voltage and a constant current are applied, the current consumed by the defective panel will be higher than the normal current value under the positive voltage, and the defective panel will generate a higher leakage current under the negative voltage. When a positive constant current and variable voltage are applied, the brightness of the panel will be relatively low or uneven. If the photodiode (photodiode) is used to convert the voltage value or the charge coupled device (Charge Coupled Device, CCD) to capture the image brightness value is uniform For comparison, the error value will increase.

In the electrical detection step (S12) of this embodiment, when the short-circuit degree of the organic light-emitting element 1 is greater than a certain value, that is, when the error result obtained by using the average value of leakage current or brightness detection is greater than an acceptable value, the organic light-emitting element 1. The step of forming the insulating layer (S13) will not be continued; and when the short circuit degree of the organic light emitting element 1 is less than a certain value, the organic light emitting element 1 will continue the step of forming the insulating layer (S13), forming an insulating layer at the disconnection 2. When the short-circuit degree of the organic light-emitting element is greater than the acceptable range, that is, when there is no repair value, the electrical detection step (S12) can reduce the loss of the isolation layer material, and only allow the organic light-emitting element that needs to be repaired to continue to be isolated Layer forming step (S13).

The method for repairing pixel defects of an organic light-emitting element provided by the present invention utilizes a method for forming an insulating layer to repair the portion of the organic light-emitting element that has a substantial short-circuit defect, so that a pixel that cannot be driven due to a substantial short-circuit can be connected to a non-defective adjacent pixel. Have equal luminous capabilities, such as efficiency, brightness, and color purity. Compared with the prior art, the present invention solves the phenomenon of leakage current, power consumption and poor image quality caused by substantial short circuit. Furthermore, the short-circuit phenomenon is tested and repaired before the packaging step, and there is no need to bear the manufacturing cost of the finished organic light-emitting element panel after the packaging step that cannot be repaired because of a substantial short circuit and can only be directly eliminated, directly improving the product quality. Yield and reliability, thereby reducing manufacturing costs.

To sum up, the present invention is different from the prior art in terms of purpose, means and efficacy, and has remarkable novelty and creativity. . It should be pointed out that the above-mentioned embodiments are examples only for the convenience of description, and the scope of rights claimed by the present invention should be determined by the scope of the claims, rather than being limited to the above-mentioned embodiments.

Claims (14)

1. A method for repairing pixel defects of an organic light-emitting element, which is used to repair an organic light-emitting element with a substantial short circuit phenomenon. The organic light-emitting element includes a first electrode, an organic light-emitting layer, and a second electrode on a substrate, and its characteristics In that, the method for repairing pixel defects of organic light-emitting elements includes the following steps: An electrical testing step, applying a current or voltage between the first electrode and the second electrode of the organic light emitting element, so as to form an open circuit at the substantially short circuit of the organic light emitting element; and An isolation layer forming step is to form an isolation layer at the disconnection of the organic light-emitting element. 2. The method for repairing pixel defects of an organic light-emitting element according to claim 1, wherein: The insulating layer forming step oxidizes the second electrode in a water-free oxygen-containing atmosphere. 3. The method for repairing pixel defects of an organic light-emitting element according to claim 1, wherein: The insulating layer partially penetrates into the organic light-emitting layer. 4. The method for repairing pixel defects of an organic light-emitting element according to claim 1, wherein: The insulating layer material is the same as the organic light emitting layer material. 5. The method for repairing pixel defects of an organic light-emitting element according to claim 1, wherein: The insulating layer material is selected from at least one organic and inorganic material with high resistance. 6. The method for repairing pixel defects of an organic light-emitting element according to claim 1, wherein: The insulating layer material is a polymer material with high resistance. 7. A method for repairing pixel defects of an organic light-emitting element, which is used to repair an organic light-emitting element with a substantial short circuit phenomenon. The organic light-emitting element includes a first electrode, an organic light-emitting layer, and a second electrode on the substrate, and its characteristics In that, the method for repairing pixel defects of organic light-emitting elements includes the following steps: An electrical testing step, using a current or voltage applied between the first electrode and the second electrode of the organic light emitting element to form an open circuit at the substantially short circuit of the organic light emitting element; an electrical testing step, detecting the degree of short circuit of the organic light-emitting element in the electrical testing step; and An isolation layer forming step is to form an isolation layer at the open circuit when the degree of short circuit detected in the electrical testing step is less than a certain value. 8. The method for repairing pixel defects of an organic light-emitting element according to claim 7, wherein: The degree of short circuit is the ratio of short circuit divided by open circuit. 9. The method for repairing pixel defects of an organic light-emitting element according to claim 7, wherein: The degree of short circuit is the degree of leakage current. 10. The method for repairing pixel defects of an organic light-emitting element according to claim 7, wherein: The insulating layer forming step oxidizes the second electrode in a water-free oxygen-containing atmosphere. 11. The method for repairing pixel defects of an organic light-emitting element according to claim 7, wherein: The insulating layer partially penetrates into the organic light-emitting layer. 12. The method for repairing pixel defects of an organic light-emitting element according to claim 7, wherein: The insulating layer material is the same as the organic light emitting layer material. 13. The method for repairing pixel defects of an organic light-emitting element according to claim 7, wherein: The insulating layer material is selected from at least one organic and inorganic material with high resistance. 14. The method for repairing pixel defects of an organic light-emitting element according to claim 7, wherein: The insulating layer material is a polymer material with high resistance.

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