A silicon-based OLED microdisplay for reducing crosstalk effect and a preparation method thereof

Abstract

The present invention discloses a silicon-based OLED microdisplay capable of reducing crosstalk effect and a preparation method thereof. The preparation method comprises the following steps: preparing an inorganic thin film layer on a pixel definition layer, wherein the edge of the inorganic thin film layer is aligned with the edge of the pixel definition layer, and the angle between the edges of the two and the surface of an anode is a right angle; then, vapor deposition of an OLED layer is performed, and the upper surface of the OLED layer vapor-deposited on the surface of the anode is lower than the upper surface of the inorganic thin film layer. This method can isolate the OLED layers between adjacent pixels to avoid mutual transmission of current, thereby avoiding abnormal luminescence of pixels and reducing the crosstalk effect.

Description

Technical Field

[0001] The present invention belongs to the technical field of silicon-based OLED microdisplays, and particularly relates to a silicon-based OLED microdisplay for reducing crosstalk effect and a preparation method thereof. Background Art

[0002] In micro OLED products, due to the small pixel size, the evaporation of OLED materials cannot use FMM (fine metal mask), so the OLED materials are evaporated over the entire surface. In this way, the organic layers between adjacent pixels are prone to mutual current transmission. The lateral current transmission of the organic material between adjacent pixels will cause abnormal light emission of the pixels, resulting in the phenomenon of crosstalk, leading to problems such as color deviation and reduced color gamut.

[0003] If the current transmission path between the organic layers of adjacent pixels can be blocked, the crosstalk effect can be reduced. Many methods for reducing the crosstalk effect by blocking the current transmission path between the organic layers of adjacent pixels have also been disclosed in the prior art, but these methods have complex processes and difficult operations. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a silicon-based OLED microdisplay for reducing crosstalk effect and a preparation method thereof.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A preparation method of a silicon-based OLED microdisplay for reducing crosstalk effect, an inorganic thin film layer is prepared on the pixel definition layer, the edge of the inorganic thin film layer is aligned with the edge of the pixel definition layer, and the included angle between the two edges and the anode surface is a right angle; then the evaporation of the OLED layer is carried out, and the upper surface of the OLED layer evaporated on the anode surface is lower than the upper surface of the inorganic thin film layer.

[0007] The preparation method specifically includes the following steps:

[0008] (1) Prepare a CMOS driving circuit on a silicon wafer substrate to form a CMOS substrate;

[0009] (2) Prepare an anode on the CMOS substrate;

[0010] (3) Prepare a pixel definition layer on the anode;

[0011] (4) Deposit an inorganic thin film layer, and etch the inorganic thin film layer through a yellow light process to remove the inorganic thin film layer outside the surface of the pixel definition layer, and make the width of the inorganic thin film layer smaller than the width of the pixel definition layer, so that the pixel definition layer exposed outside the coverage of the inorganic thin film layer can be simply and quickly removed by ashing in subsequent steps;

[0012] (5) By ashing the BM glue of the pixel definition layer, the edge of the pixel definition layer is aligned with the edge of the inorganic thin film layer, and the angle between the edges of both and the anode surface is a right angle. In this way, in subsequent steps, it only needs to control that the upper surface of the OLED layer evaporated on the anode surface is lower than the upper surface of the inorganic thin film layer to cut off the OLED layer between adjacent pixels and avoid the mutual transmission of current, thereby avoiding abnormal light emission of pixels and reducing the crosstalk effect;

[0013] (6) Evaporate the OLED layer and the cathode, and the upper surface of the OLED layer evaporated on the anode surface is lower than the upper surface of the inorganic thin film layer;

[0014] (7) Prepare the encapsulation layer;

[0015] (8) Complete the subsequent yellow light and module processes.

[0016] In step (6), the OLED layer sequentially includes a hole injection layer or a hole transport layer, an organic light-emitting layer, and an electron injection layer or an electron transport layer from bottom to top.

[0017] The material of the inorganic thin film layer is any one or more of SiN, alumina, and ATO; the deposition method of the inorganic thin film layer is PECVD or ALD.

[0018] The material of the encapsulation layer is Al 2 O 3 、TiO 2 、ATO, SiN, SiON, SiO, acrylic-based organic substances, epoxy resin-based organic substances, etc.

[0019] The preparation method of the encapsulation layer is ALD, PECVD or IJP.

[0020] In step (4), the width difference between the pixel definition layer and the inorganic thin film layer is

[0021] The vertical height difference between the upper surface of the anode and the edge of the inorganic thin film layer is

[0022] The thickness of the inorganic thin film layer is

[0023] The present invention also provides a silicon-based OLED microdisplay prepared by the preparation method, which can effectively prevent the lateral current between pixels and reduce the crosstalk effect.

[0024] In the method for manufacturing a silicon-based OLED microdisplay for reducing crosstalk effect provided by the present invention, an inorganic thin film layer is prepared on the pixel definition layer, and the edge of the inorganic thin film layer is aligned with the edge of the pixel definition layer, and the angle between the two edges and the anode surface is a right angle. In this way, when depositing the OLED layer subsequently, it is only necessary to control the upper surface of the OLED layer deposited on the anode surface to be lower than the upper surface of the inorganic thin film layer to block the OLED layer between adjacent pixels and avoid the mutual transmission of current, thereby avoiding abnormal light emission of pixels and reducing the crosstalk effect.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. The process is simple and easy to operate;

[0027] 2. The width and edge shape of the pixel definition layer can be arbitrarily adjusted by first etching the inorganic thin film layer and then ashing the BM glue of the pixel definition layer. In the present invention, the edge of the pixel definition layer is adjusted to be aligned with the edge of the inorganic thin film layer, and the angle between the two edges and the anode surface is a right angle, so that it is easy to control the upper surface of the OLED layer deposited on the anode surface to be lower than the upper surface of the inorganic thin film layer in the subsequent steps;

[0028] 3. The thickness of the inorganic thin film layer can be adjusted according to the thickness of the OLED layer. It is only necessary to ensure that the upper surface of the OLED layer deposited on the anode surface is lower than the upper surface of the inorganic thin film layer to block the OLED layer between adjacent pixels and avoid the mutual transmission of current, thereby avoiding abnormal light emission of pixels and reducing the crosstalk effect. This method can be applied to a wide range of products. Description of the Drawings

[0029] Figure 1 Schematic diagram of preparing an anode on a CMOS substrate;

[0030] Figure 2 Schematic diagram of preparing a pixel definition layer on the anode;

[0031] Figure 3 Schematic diagram of depositing an inorganic thin film layer;

[0032] Figure 4 Schematic diagram of etching the inorganic thin film layer;

[0033] Figure 5 Schematic diagram of right-angling the edges of the pixel definition layer and the inorganic thin film layer;

[0034] Figure 6 Schematic diagram of depositing the OLED layer 6 and the cathode 7

[0035] Figure 7 Schematic diagram of preparing the encapsulation layer 8

[0036] Figure 8 Schematic diagram prepared for subsequent yellow light and module processes;

[0037] Among them, 1 - CMOS substrate, 2 - anode, 3 - pixel definition layer, 4 - inorganic thin film layer, 5 - OLED layer, 6 - cathode, 7 - encapsulation layer, 8 - first OC layer, 9 - color resist layer, 10 - second OC layer, 11 - glass cover plate. Specific implementation mode

[0038] The present invention will be described in detail below in conjunction with embodiments.

[0039] The present invention provides a method for manufacturing a silicon-based OLED microdisplay with reduced crosstalk effect. An inorganic thin film layer is prepared on the pixel definition layer. The edge of the inorganic thin film layer is aligned with the edge of the pixel definition layer, and the angle between the two edges and the anode surface is a right angle; then the OLED layer is evaporated, and the upper surface of the OLED layer evaporated on the anode surface is lower than the upper surface of the inorganic thin film layer.

[0040] The manufacturing method specifically includes the following steps:

[0041] (1) Prepare a CMOS driving circuit on a silicon wafer substrate to form a CMOS substrate;

[0042] (2) Prepare an anode 2 on the CMOS substrate 1, as Figure 1 shown;

[0043] (3) Prepare a pixel definition layer 3 on the anode 2, as Figure 2 shown;

[0044] (4) Deposit an inorganic thin film layer 4, as Figure 3 shown; and etch the inorganic thin film layer through a yellow light process to remove the inorganic thin film layer outside the surface of the pixel definition layer, and make the width of the inorganic thin film layer smaller than the width of the pixel definition layer, as Figure 4 shown;

[0045] (5) Align the edge of the pixel definition layer with the edge of the inorganic thin film layer by ashing the BM glue of the pixel definition layer, and the angle between the two edges and the anode surface is a right angle, as Figure 5 shown;

[0046] (6) Evaporate the OLED layer 5 and the cathode 6, and the upper surface of the OLED layer evaporated on the anode surface is lower than the upper surface of the inorganic thin film layer; as Figure 6 described,

[0047] (7) Prepare an encapsulation layer 7, as Figure 7 shown;

[0048] (8) Complete subsequent yellow light and module processes, asFigure 8 as shown

[0049] Specifically, in step (4), the thickness of the inorganic thin film layer is The material of the inorganic thin film layer is any one or more of SiN, aluminum oxide, and ATO; the deposition method of the inorganic thin film layer is PECVD or ALD.

[0050] In step (4), the width difference between the pixel definition layer and the inorganic thin film layer is

[0051] In step (6), the vertical height difference between the upper surface of the anode and the edge of the inorganic thin film layer is

[0052] In step (6), the OLED layer sequentially includes a hole injection layer or a hole transport layer, an organic light emitting layer, and an electron injection layer or an electron transport layer from bottom to top.

[0053] In step (7), the material of the encapsulation layer is Al 2 O 3 , TiO 2 , ATO, SiN, SiON, SiO, acrylic-based organic substances, epoxy resin-based organic substances, or any one or more of them; the preparation method of the encapsulation layer is ALD, PECVD, or IJP.

[0054] In step (8), the subsequent yellow light and module processes include a first OC layer 8, a color resin layer 9, and a second OC layer 10, and finally a glass cover plate 11 is bonded on the second OC layer 10.

[0055] The above detailed description of a silicon-based OLED microdisplay and its manufacturing method for reducing crosstalk effect with reference to the embodiments is illustrative rather than restrictive. Several embodiments can be listed within the defined scope. Therefore, changes and modifications without departing from the general concept of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for fabricating a silicon-based OLED microdisplay to reduce crosstalk effect, characterized in that, an inorganic thin film layer is fabricated on the pixel definition layer, the edge of the inorganic thin film layer is aligned with the edge of the pixel definition layer, and the angle between the edges of both and the anode surface is a right angle; then, the OLED layer is evaporated, and the upper surface of the OLED layer evaporated on the anode surface is lower than the upper surface of the inorganic thin film layer; the fabrication method specifically includes the following steps: (1) Fabricate a CMOS driving circuit on a silicon wafer substrate to form a CMOS substrate; (2) Fabricate an anode on the CMOS substrate; (3) Fabricate a pixel definition layer on the anode; (4) Deposit an inorganic thin film layer, and etch the inorganic thin film layer through a yellow light process to remove the inorganic thin film layer outside the surface of the pixel definition layer, and make the width of the inorganic thin film layer smaller than the width of the pixel definition layer; (5) Align the edge of the pixel definition layer with the edge of the inorganic thin film layer by ashing the BM glue of the pixel definition layer, and the angle between the edges of both and the anode surface is a right angle; (6) Evaporate the OLED layer and the cathode, and the upper surface of the OLED layer evaporated on the anode surface is lower than the upper surface of the inorganic thin film layer; (7) Fabricate a packaging layer; (8) Complete subsequent yellow light and module processes.

2. The fabrication method according to claim 1, characterized in that, in step (6), the OLED layer sequentially includes a hole injection layer or a hole transport layer, an organic light-emitting layer, an electron injection layer or an electron transport layer, and a cathode from bottom to top.

3. The fabrication method according to claim 1, characterized in that, in step (4), the width difference between the pixel definition layer and the inorganic thin film layer is 300 - 400 Å.

4. The fabrication method according to claim 1, characterized in that, the vertical height difference between the upper surface of the anode and the edge of the inorganic thin film layer is 750 - 800 Å.

5. The fabrication method according to claim 1, characterized in that, the thickness of the inorganic thin film layer is 400 - 500 Å.

6. The fabrication method according to claim 1, characterized in that, the material of the inorganic thin film layer is any one or more of SiN, aluminum oxide, and ATO; the deposition method of the inorganic thin film layer is PECVD or ALD.

7. The fabrication method according to claim 1, characterized in that, The material of the encapsulation layer is Al 2 O 3 , TiO 2 , ATO, SiN, SiON, SiO, acrylic-based organic compounds, epoxy resin-based organic compounds, or any one or more of them.

8. The fabrication method according to claim 1, characterized in that, the fabrication method of the packaging layer is ALD, PECVD or IJP.

9. A silicon-based OLED microdisplay fabricated by the fabrication method according to any one of claims 1 - 8.

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