Micro-LED full-color display preparation method based on electrofluid printing

Abstract

The invention discloses a Micro-LED full-color display preparation method based on electrofluid printing, and relates to the technical field of display preparation. The preparation method comprises the steps that cylindrical grooves are etched in the surface of glass, the electrofluid printing technology is utilized, BM grid lines are printed on the surface of the glass, a light blocking matrix layer is prepared, the grooves serve as line intersection points to be filled with black photoresist, then quantum dots are printed in grids, and a full-color quantum dot film layer is prepared; curing by irradiating the sample wafer of the full-color quantum dot film layer in a nitrogen atmosphere; preparing a SiN packaging layer on the surface of the sample wafer by using plasma enhanced chemical vapor deposition; and after a layer of UV resin adhesive is spin-coated on the surface of the LED epitaxial wafer, a bonding machine is used for carrying out pixel position alignment, and then the sample wafer is irradiated for curing. According to the invention, the quantum dot material can be accurately deposited on the Micro-LED display by using the electrofluid printing technology, so that efficient color conversion and full-color display are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of display preparation, and in particular to a method for preparing a Micro-LED full-color display based on electrofluid printing. Background Art

[0002] As an emerging display technology, Micro-LED display technology has the advantages of high brightness, high contrast, low power consumption and fast response, and has gradually become a research hotspot for the next generation of displays. However, achieving high-quality full-color display still faces many challenges, especially in color conversion and manufacturing process.

[0003] The current mainstream patterning technologies include photolithography, inkjet printing, etc. This method has the following problems: Photolithography technology requires multiple exposure and development processes in the process of preparing the BM layer and the quantum dot film layer, resulting in high manufacturing costs and material waste. In addition, the complexity of the photolithography process also increases the difficulty of production and the defective rate. The minimum pixel size of traditional piezoelectric inkjet printing is usually greater than 50μm, and can only achieve a resolution of up to 500PPI. Summary of the invention

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

[0005] To achieve the above object, the present invention provides the following solutions:

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

[0007] Etching cylindrical grooves on the glass surface, and using electrofluidic printing technology, printing BM grid lines on the glass surface with cylindrical grooves to prepare a light-blocking matrix layer, wherein the grooves as the intersections of the lines will be filled with black photoresist, and then printing quantum dots in the grid to prepare a full-color quantum dot film layer;

[0008] Curing the sample of the full-color quantum dot film layer by irradiating it in a nitrogen atmosphere;

[0009] A SiN encapsulation layer was prepared on the surface of the sample by plasma enhanced chemical vapor deposition;

[0010] Spin-coat a layer of UV resin glue on the surface of the LED epitaxial wafer without curing;

[0011] Use a bonding machine to align the pixel positions of the full-color quantum dot film layer and the Micro-LED chip, and then irradiate the sample for curing.

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

[0013] Spin-coat a positive photoresist on the glass surface, expose the circular array through a photolithography process, etch a circular groove using hydrofluoric acid, and remove the surface photoresist using a special developer;

[0014] Electrofluid printing technology is used to print BM grid lines on a glass surface engraved with cylindrical grooves to prepare a light-blocking matrix layer; 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 layer is specifically as follows:

[0016] Using inductively coupled plasma etching to flatten the target surface using Ar; the target surface includes the substrate surface and the BM layer surface of the Micro-LED chip;

[0017] Red and green quantum dot inks and blank inks are printed on the target surface using electrofluidic printing technology to prepare a full-color quantum dot film layer.

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

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

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

[0021] The present invention discloses a method for preparing a Micro-LED full-color display based on electrofluid printing, the method comprising etching a cylindrical groove on a glass surface, and using electrofluid printing technology to print BM grid lines on the glass surface with the cylindrical grooves to prepare a light-blocking matrix layer, wherein the grooves as the intersections of the lines will be filled with black photoresist, and then printing quantum dots in the grid to prepare a full-color quantum dot film layer; curing by irradiating a sample of the full-color quantum dot film layer under a nitrogen atmosphere; preparing a SiN encapsulation layer on the surface of the sample by plasma enhanced chemical vapor deposition; spin coating a layer of UV resin glue on the surface of the LED epitaxial wafer without curing; aligning the pixel positions of the full-color quantum dot film layer and the Micro-LED chip by using a bonding machine, and then irradiating the sample for curing. The present invention can use electrofluid printing technology to accurately deposit quantum dot materials on a Micro-LED display, thereby achieving efficient color conversion and full-color display. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0023] Figure 1 Schematic diagram of the cross-sectional structure of a Micro-LED full-color display device prepared by electrofluid printing in this embodiment;

[0024] Figure 2 Schematic diagram of the surface structure of the full-color quantum dot film layer in this embodiment. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

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

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] like Figure 1-Figure 2 As shown, the present invention provides a method for preparing a Micro-LED full-color display based on electrofluid printing, comprising:

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

[0030] Step 102: Printing a black negative photoresist doped with Ag nanoparticles using electrohydrodynamic printing technology (EHD) to serve as a light-blocking matrix layer;

[0031] Step 103: using inductively coupled plasma etching (ICP) to process the substrate surface and the BM layer surface by Ar to improve the surface flatness of the BM layer;

[0032] Step 104: using electrofluidic printing technology to print red and green quantum dot inks and blank ink to prepare a full-color quantum dot film layer, with a voltage of 0.6 kV and a nozzle diameter of 3 μm;

[0033] Step 105: using a high-power UV curing lamp to irradiate the sample printed with the quantum dot film layer in a nitrogen atmosphere for curing;

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

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

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

[0037] As a further embodiment, 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] Since photolithography technology requires multiple exposures and developments when preparing the BM layer and quantum dot film layer, it leads to high costs and material waste, and the complex process increases the difficulty of production and the rate of defective products. The minimum pixel size of traditional piezoelectric inkjet printing is greater than 50μm, and the resolution is only 500PPI. In contrast, electrohydrodynamic (EHD) printing, as a maskless, high-material utilization, non-contact printing technology, has received widespread attention in recent years. Traditional inkjet printing uses piezoelectric ceramics to squeeze out ink. In contrast, EHD printing induces charge accumulation on the air-liquid surface of the suspended meniscus by applying a voltage between the nozzle and the substrate, thereby achieving higher resolution printing.

[0039] Therefore, the purpose of this embodiment is to provide a method for manufacturing a Micro-LED full-color display device based on electrofluid printing to solve the high cost and material waste problems caused by traditional photolithography. More precise material deposition is achieved through electrofluid printing technology, and the resolution and image quality of the Micro-LED full-color display are improved, thereby achieving efficient color conversion and full-color display, and simplifying the manufacturing process of the color conversion layer for easy industrial application.

[0040] Based on the traditional color conversion layer, the present invention (1) prints black photoresist after etching circular holes on a borosilicate glass sheet with hydrofluoric acid in advance, thereby avoiding light crosstalk and improving color conversion efficiency; and (2) prints the BM layer and quantum dot film layer with electrofluid printing technology, which simplifies the process flow, reduces the process cost, and improves the resolution and image quality of the Micro-LED full-color display while performing precise material deposition.

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

[0042] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for preparing a Micro-LED full-color display based on electrofluid printing, characterized in that: include: Etching cylindrical grooves on the glass surface, and using electrofluidic printing technology, printing BM grid lines on the glass surface with cylindrical grooves to prepare a light-blocking matrix layer, wherein the grooves as the intersections of the lines will be filled with black photoresist, and then printing quantum dots in the grid to prepare a full-color quantum dot film layer; Using electrofluidic printing technology, the BM layer and quantum dot film layer are processed to prepare a full-color quantum dot film layer; Curing the sample of the full-color quantum dot film layer by irradiating it in a nitrogen atmosphere; A SiN encapsulation layer was prepared on the surface of the sample by plasma enhanced chemical vapor deposition; Spin-coat a layer of UV resin glue on the surface of the LED epitaxial wafer without curing; Use a bonding machine to align the pixel positions of the full-color quantum dot film layer and the Micro-LED chip, and then irradiate the sample for curing.

2. The method for preparing a Micro-LED full-color display based on electrofluid printing according to claim 1, characterized in that: The preparation process of the light-blocking matrix layer is specifically as follows: Spin-coat a positive photoresist on the glass surface, expose the circular array through a photolithography process, etch a circular groove using hydrofluoric acid, and remove the surface photoresist using a special developer; The electrofluidic printing technology is used to print BM grid lines on the glass surface engraved with cylindrical grooves to prepare a light-blocking matrix layer; The BM grid lines are composed of black negative photoresist doped with Ag nanoparticles.

3. The method for preparing a Micro-LED full-color display based on electrofluid printing according to claim 1, characterized in that: The preparation process of the full-color quantum dot film layer is specifically as follows: Using inductively coupled plasma etching to flatten the target surface using Ar; the target surface includes the substrate surface and the BM layer surface of the Micro-LED chip; Red and green quantum dot inks and blank inks are printed on the target surface using electrofluidic printing technology to prepare a full-color quantum dot film layer.

4. The method for preparing a Micro-LED full-color display based on electrofluid printing according to claim 3, characterized in that: The electrofluid printing technology uses a 0.6 kV voltage and a 3 μm nozzle aperture.

5. The method for preparing a Micro-LED full-color display based on electrofluid printing according to claim 1, characterized in that: The curing method is to use UV curing lamp irradiation.

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