A method for preparing a micro-LED full-color display based on electrohydrodynamic printing

Abstract

The application discloses a Micro-LED full-color display preparation method based on electrohydrodynamic printing and relates to the technical field of display preparation. The preparation method comprises the following steps: etching a cylindrical groove on a glass surface, printing BM square grid lines on the glass surface by using an electrohydrodynamic printing technology, and preparing a light-blocking matrix layer, wherein the groove is filled with black photoresist as line intersection points, quantum dots are printed in the square grid, and a full-color quantum dot film layer is prepared; curing is performed on a sample of the full-color quantum dot film layer by irradiation in a nitrogen atmosphere; a SiN encapsulation layer is prepared on the surface of the sample by using plasma-enhanced chemical vapor deposition; after a layer of UV resin glue is spin-coated on the surface of an LED epitaxial wafer, pixel position alignment is performed by using a bonding machine, and then the sample is irradiated and cured. The application can precisely deposit quantum dot materials on a Micro-LED display by using the electrohydrodynamic printing technology, so that efficient color conversion and full-color display are realized.

Description

Technical Field

[0001] This invention relates to the field of display fabrication technology, and in particular to a method for fabricating a Micro-LED full-color display based on electrofluid printing. Background Technology

[0002] Micro-LED display technology, as an emerging display technology, boasts advantages such as high brightness, high contrast, low power consumption, and fast response, and is gradually becoming a research hotspot for next-generation displays. However, achieving high-quality full-color displays still faces many challenges, especially in color conversion and manufacturing processes.

[0003] Currently, mainstream patterning technologies include photolithography and inkjet printing. These methods have the following problems: photolithography requires multiple exposure and development processes during the fabrication of the BM layer and quantum dot film, leading to high manufacturing costs and material waste. Furthermore, the complexity of the photolithography process increases production difficulty and defect rates. Traditional piezoelectric inkjet printing typically has a minimum pixel size greater than 50μm, achieving a resolution of only up to 500 PPI. Summary of the Invention

[0004] The purpose of this invention is to provide a method for fabricating a Micro-LED full-color display based on electrofluid printing, which can accurately deposit quantum dot materials on a Micro-LED display using electrofluid printing technology, thereby achieving efficient color conversion and full-color display.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] A method for fabricating a Micro-LED full-color display based on electrofluid printing, comprising:

[0007] Cylindrical grooves are etched on the glass surface, and BM grid lines are printed on the glass surface with cylindrical grooves using electrohydrodynamic printing technology to prepare a light-blocking matrix layer. The grooves, which serve as the intersection points of the lines, are filled with black photoresist. Quantum dots are then printed in the grid to prepare a full-color quantum dot film layer.

[0008] The full-color quantum dot film was cured by irradiating a sample under a nitrogen atmosphere.

[0009] SiN encapsulation layers were prepared on the surface of a sample using plasma-enhanced chemical vapor deposition.

[0010] A layer of UV resin adhesive is spin-coated onto the surface of the LED epitaxial wafer, but it is not cured.

[0011] The full-color quantum dot film and the pixel positions of the Micro-LED chip are aligned using a bonding machine, and then the sample is irradiated for curing.

[0012] Optionally, the fabrication process of the light-blocking matrix layer is as follows:

[0013] Positive photoresist is spin-coated onto the glass surface, and a circular array is exposed through photolithography. Circular grooves are etched using hydrofluoric acid, and the surface photoresist is removed using a special developer.

[0014] A light-blocking matrix layer is prepared by printing BM grid lines on a glass surface with cylindrical grooves using electrohydrodynamic printing technology; the BM grid lines are composed of black negative photoresist doped with Ag nanoparticles.

[0015] Optionally, the preparation process of the full-color quantum dot film is as follows:

[0016] The target surface is planarized by using inductively coupled plasma etching (ICP-AL) with Ar. The target surface includes the substrate surface of the Micro-LED chip and the surface of the BM layer.

[0017] A full-color quantum dot film was prepared by printing red and green quantum dot inks and blank inks on the target surface using electrofluid printing technology.

[0018] Optionally, the electrofluid printing technology uses a 0.6kV voltage and a 3μm nozzle diameter.

[0019] Optionally, the curing method employs UV curing lamp irradiation.

[0020] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0021] This invention discloses a method for fabricating a Micro-LED full-color display based on electrofluid printing. The method includes etching cylindrical grooves on a glass surface, and using electrofluid printing technology to print BM grid lines on the glass surface with the etched cylindrical grooves to prepare a light-blocking matrix layer. The grooves, serving as the intersection points of the lines, are filled with black photoresist. Quantum dots are then printed within the grid to prepare a full-color quantum dot film layer. The full-color quantum dot film layer is cured by irradiating a sample under a nitrogen atmosphere. A SiN encapsulation layer is prepared on the sample surface using plasma-enhanced chemical vapor deposition. A layer of UV resin is spin-coated onto the surface of an LED epitaxial wafer and left uncured. The full-color quantum dot film layer and the pixel positions of the Micro-LED chip are aligned using a bonding machine, followed by irradiation of the sample for curing. This invention enables the precise deposition of quantum dot materials on a Micro-LED display using electrofluid printing technology, thereby achieving efficient color conversion and full-color display. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic cross-sectional view of the Micro-LED full-color display device fabricated using electrofluid printing in this embodiment;

[0024] Figure 2 This is a schematic diagram of the surface structure of the full-color quantum dot film in this embodiment. Detailed Implementation

[0025] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] The purpose of this invention is to provide a method for fabricating a Micro-LED full-color display based on electrofluid printing, which can accurately deposit quantum dot materials on a Micro-LED display using electrofluid printing technology, thereby achieving efficient color conversion and full-color display.

[0027] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] like Figures 1-2 As shown, this invention provides a method for fabricating a Micro-LED full-color display based on electrofluid printing, comprising:

[0029] Step 101: Spin-coat positive photoresist onto the glass surface, expose the circular array through photolithography, etch circular grooves with hydrofluoric acid (HF), and remove the surface photoresist with a special developer.

[0030] Step 102: Print a black negative photoresist doped with Ag nanoparticles using electrohydrodynamic (EHD) printing technology, which will be used as a light-blocking matrix layer;

[0031] Step 103: Inductively coupled plasma etching (ICP) is used to process the substrate surface and BM layer surface with Ar to improve the surface flatness of the BM layer.

[0032] Step 104: Use electrofluid printing technology to print red and green quantum dot inks and blank inks to prepare a full-color quantum dot film layer. The voltage is 0.6kV and the nozzle diameter is 3μm.

[0033] Step 105: Curing the printed quantum dot film by irradiating it with a high-power UV curing lamp under a nitrogen atmosphere;

[0034] Step 106: Prepare a SiN encapsulation layer on the surface of the quantum dot film using plasma-enhanced chemical vapor deposition (PECVD);

[0035] Step 107: Spin-coat a layer of UV resin adhesive onto the surface of the LED epitaxial wafer, without curing;

[0036] Step 108: Use a bonding machine to align the quantum dot film pixels and the Micro-LED chip pixels, and then use a UV curing lamp to irradiate the sample for curing.

[0037] As a further implementation, the above-mentioned patterning process includes processes such as thin film deposition, photoresist coating, photolithography, development, wet etching, inkjet printing, photoresist removal, and dry etching.

[0038] Because photolithography requires multiple exposures and developments to fabricate BM layers and quantum dot films, it leads to high costs and material waste, and the complex process increases production difficulty and defect rate. Traditional piezoelectric inkjet printing has a minimum pixel size greater than 50μm and a resolution of only 500PPI. In contrast, electrohydrodynamic (EHD) printing, as a maskless, high-material-utilization non-contact printing technology, has received widespread attention in recent years. Unlike traditional inkjet printing, which uses piezoelectric ceramics to extrude ink, EHD printing achieves higher resolution printing by applying a voltage between the nozzle and the substrate to induce charge accumulation on the air-liquid surface of a suspended meniscus.

[0039] Therefore, the purpose of this embodiment is to provide a method for manufacturing Micro-LED full-color display devices based on electrofluid printing, so as to solve the problems of high cost and material waste caused by traditional photolithography processes. By using electrofluid printing technology to achieve more precise material deposition, the resolution and image quality of Micro-LED full-color displays are improved, thereby achieving efficient color conversion and full-color display, and simplifying the manufacturing process of the color conversion layer, facilitating industrial applications.

[0040] Based on the traditional color conversion layer, this invention (1) pre-etches circular holes on a high borosilicate glass sheet with hydrofluoric acid and then prints black photoresist to avoid light crosstalk and improve color conversion efficiency; (2) prints the BM layer and quantum dot film layer using electrofluid printing technology. Based on precise material deposition, it simplifies the process flow, reduces process costs, and improves the resolution and image quality of Micro-LED full-color displays.

[0041] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0042] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for fabricating a full-color Micro-LED display based on electrohydrodynamic printing, characterized in that, The application relates to a preparation method of a full-color quantum dot film. A cylindrical groove is etched on a glass surface, and a BM square line is printed on the glass surface with the cylindrical groove by using an electrohydrodynamic printing technology to prepare a light-blocking matrix layer, wherein the groove is filled with black photoresist as a line intersection point, and quantum dots are printed in the square to prepare a full-color quantum dot film layer; The electrohydrodynamic printing technology is used to process the BM layer and the quantum dot film layer to prepare the full-color quantum dot film layer; The sample of the full-color quantum dot film layer is cured by irradiation under a nitrogen atmosphere; An SiN encapsulation layer is prepared on the sample surface by using a plasma-enhanced chemical vapor deposition method; A layer of UV resin glue is spin-coated on the surface of an LED epitaxial wafer without curing; A bonding machine is used to align the pixel positions of the full-color quantum dot film layer and the Micro-LED chip, and then the sample is irradiated for curing. 2.The method of claim 1, wherein The preparation process of the light-blocking matrix layer is specifically as follows: A positive photoresist is spin-coated on a glass surface, a circular array is exposed by a photoetching process, a circular groove is etched by using hydrofluoric acid, and the surface photoresist is removed by using a special developing solution; The electrohydrodynamic printing technology is used to print a BM square line on the glass surface with the cylindrical groove to prepare a light-blocking matrix layer. The BM square line is composed of black negative photoresist doped with Ag nanoparticles. 3.The method of claim 1, wherein, The preparation process of the full-color quantum dot film layer is specifically as follows: A target surface including a substrate surface of a Micro-LED chip and a BM layer surface is planarized by using an inductively coupled plasma etching method through Ar; The electrohydrodynamic printing technology is used to print red and green quantum dot inks and blank inks on the target surface to prepare a full-color quantum dot film layer.

4. The method of claim 3, wherein the method further comprises: The electrohydrodynamic printing technology adopts a 0.6kV voltage and a 3mu m nozzle aperture.

5. The method of claim 1, wherein the method further comprises: The curing method adopts UV curing lamp irradiation.

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