CN110614863B - Method for realizing uniform pattern array of ink-jet printing - Google Patents

Abstract

The invention belongs to the technical field of ink-jet printing, and discloses a method for realizing uniform pattern array ink-jet printing. Pretreating a glass substrate, spin-coating a layer of polymer solution, and carrying out ultraviolet curing to obtain a polymer film; the polymer film is compatible with a solvent of subsequent ink-jet printing ink; and (3) carrying out ink-jet printing on the uniform ink drop array on the polymer film by using ink-jet printing ink, and naturally cooling after annealing treatment to obtain a uniform pattern array. According to the invention, a layer of polymer film is prepared in advance before ink-jet printing, and a high-precision uniform pattern array can be obtained by utilizing the coffee ring effect in the ink-jet printing process, so that the limit of the traditional preparation method is broken through, and the obtained pattern array has good repeatability and uniformity.

Description

A method for realizing inkjet printing of uniform pattern array

technical field

The invention belongs to the technical field of ink jet printing, and in particular relates to a method for realizing ink jet printing of uniform pattern arrays.

Background technique

Inkjet Printing is a bottom-up additive manufacturing patterning technology, which has the advantages of no vacuum, direct patterning, low temperature, low cost, and environmental friendliness. It is widely used in the preparation of thin-film electronic devices such as capacitors, thin-film transistors, organic light-emitting diodes, and organic solar cells.

In the process of inkjet printing, the final morphology of droplets on the printing substrate is the result of a combination of factors such as the evaporation of the droplets, the surface tension of the droplets, and the surface energy of the substrate. Ink droplets are usually deposited on the surface of the substrate in a spherical shape. Due to its special geometry, the solvent evaporation rate at the edge of the droplet is greater than the solvent evaporation rate at the center of the droplet, thereby forming a radial capillary from the center of the droplet to the edge of the droplet. flow to compensate for solvent loss due to evaporation from the droplet edge. The radial capillary flow will drive the solute inside the droplet to move to the edge of the droplet, eventually forming a ring-shaped structure, which is called the "coffee ring" effect. The coffee ring phenomenon can lead to uneven deposition of droplets on the surface of the substrate, but by using the coffee ring phenomenon, some regular patterns can also be formed under specific conditions to meet specific needs. Due to the limitation of instrument precision, the lowest line width that can be achieved by conventional piezoelectric inkjet printing technology is about 20 μm, which limits its application in printing high-definition, large-area uniform arrays.

SUMMARY OF THE INVENTION

In view of the above shortcomings and deficiencies in the prior art, the purpose of the present invention is to provide a method for realizing inkjet printing of uniform pattern arrays.

The object of the present invention is achieved through the following technical solutions:

A method for realizing ink jet printing of uniform pattern array, comprising the steps of:

(1) preparing a layer of polymer film on the pretreated glass substrate; the polymer film is compatible with the solvent of the subsequent inkjet printing ink;

(2) inkjet printing ink jet printing a uniform ink droplet array on the polymer film of step (1), and cooling naturally after annealing to obtain a uniform pattern array.

Preferably, the pretreatment in step (1) refers to ultrasonic cleaning with tetrahydrofuran, isopropanol, washing solution, deionized water and isopropanol in sequence, drying, and then oxygen plasma treatment. In order to remove impurities on the surface of the glass substrate and increase the surface energy of the substrate.

Preferably, the polymer film in step (1) refers to a polyvinylpyrrolidone (PVP) film; the inkjet printing ink in step (2) is a silver nanoparticle ink using triethylene glycol ether as a solvent.

Further, the polyvinylpyrrolidone film is prepared by the following method: spin-coating a polymer solution containing polymer PVP, curing agent methylated poly(melamine-co-formaldehyde) and solvent ethylene glycol onto the pretreated On the glass substrate, the polyvinylpyrrolidone film is obtained by ultraviolet light curing.

Preferably, the temperature of the inkjet printing in step (2) is room temperature, and the distance between ink droplets is 150-250 μm.

Preferably, the temperature of the annealing treatment in step (2) is 150-250° C., and the time is 10 min.

The principle of the invention is as follows: when the ink droplets are deposited on the surface of the compound film, under the action of the strong coffee ring effect, the solvent in the center of the droplet moves the solute to the edge of the droplet rapidly, and the solute is deposited at the edge. And the ink solvent dissolves the underlying polymer, and further dissolves to the edge, and finally forms a circle of uniformly deposited solute at the edge of the ink droplet. If there is no polymer film, the deposition of ink droplets on the glass substrate will form three-phase line pinning, and the ink solute and solvent will be limited to a certain range. The surface of the glass substrate is deposited to form a uniform lattice (as shown in Figure 5), and it is impossible to directly form a ring structure with a uniform line width of less than 20 μm. The dissolution of the polymer film by the ink solvent will cause the three-phase line to slip, which will eventually promote uniform deposition of the solute at the edge of the ink drop. The schematic diagram of its principle is shown in Figure 1. The process principle of forming a uniform pattern array from a uniform ink droplet array is shown in FIG. 2 .

The preparation method of the present invention has the following advantages and beneficial effects:

In the present invention, a layer of polymer film is pre-prepared before inkjet printing, and the "coffee ring" effect in the inkjet printing process can be used to obtain a high-precision uniform pattern array, which breaks through the limit of the traditional preparation method, and the obtained pattern array Has good repeatability and uniformity.

Description of drawings

FIG. 1 and FIG. 2 are respectively schematic diagrams of the process of forming a pattern of ink droplets and forming a uniform pattern array from an array of uniform ink droplets in the method of the present invention. The numbers in the figure are explained as follows: 01-glass substrate, 02-polymer film, 03-inkjet printing ink solute, 04-inkjet printing ink solvent.

FIG. 3 is a diagram showing the formation process of the uniform pattern array obtained in the embodiment of the present invention.

FIG. 4 is an effect diagram of a uniform pattern array obtained in an embodiment of the present invention.

FIG. 5 is a pattern array image obtained by direct inkjet printing of a polymer-free film as a comparison.

Detailed ways

The present invention will be described in further detail below with reference to the embodiments and the accompanying drawings, but the embodiments of the present invention are not limited thereto.

Example

(1) At room temperature, the glass substrate was ultrasonically cleaned in tetrahydrofuran, isopropanol, washing solution, deionized water (2 times), and isopropanol in turn. The cleaning time for each step was 10 minutes, and then the cleaned glass substrate was placed on the Dry in a constant temperature oven at 75°C. The glass substrates were then treated with oxygen plasma for 10 min at room temperature to remove surface impurities and increase the surface energy of the substrates.

(2) Spin coat a layer of PVP solution (500mg PVP powder + 0.1ml methylated polymelamine co-formaldehyde dissolved in 5ml ethylene glycol solution to obtain 100mg/ml PVP solution at room temperature with a glue homogenizer) on the treated glass substrate. solution), the spin coating conditions are: the rotation speed is 3000 rpm, and the time is 30 s. After spin-coating, the sample was cured with a UV curing machine, and the curing time was 3 min to obtain a PVP polymer film.

(3) Dimatix 2800 series piezoelectric inkjet printer was used, silver nanoparticle ink was used as inkjet printing raw material to print uniform ink droplet array, and the ink solvent was triethylene glycol ether. The inkjet printing conditions were as follows: the temperature of the clip was set to room temperature, the temperature of the printing substrate was set to room temperature, and the distance between ink droplets was 150 μm.

(4) The printed ink droplet array was placed on a hot table for annealing at 200° C. for 10 minutes, and then cooled naturally to obtain a uniform pattern array.

FIG. 3 shows a process diagram of the formation of the uniform pattern array in this embodiment. The final result of the uniform pattern array is shown in Figure 4. From the above results, it can be seen that it has a stable repeatable structure and good uniformity. The approximate size of a single ring structure is about 150 μm*150 μm, the width of the silver nanoparticle ring is about 17 μm, the spacing between the ring structures is about 2 μm, and there is no overlap between the rings. For comparison, FIG. 5 is a pattern array diagram obtained by direct inkjet printing of a polymer-free film. It can be seen that the line width between the ring structures of the pattern array obtained by direct inkjet printing of the polymer-free film is greater than 20 μm.

To sum up, the present invention prepares a layer of polymer film in advance, and the uniform pattern array realized by the inkjet printing method has a stable repeatable structure and good uniformity, which breaks through the preparation limit of the traditional inkjet printing method.

The above-mentioned embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above-mentioned embodiments, and any other changes, modifications, substitutions, combinations, The simplification should be equivalent replacement manners, which are all included in the protection scope of the present invention.

Claims (4)

1. Use of a method for realizing an ink jet printed uniform pattern array for the preparation of uniform annular structures having a line width of less than 20 μm, characterized in that the method comprises the steps of:

(1) preparing a layer of polymer film on the pretreated glass substrate; the polymer film is compatible with a solvent of subsequent ink-jet printing ink;

(2) carrying out ink-jet printing on the uniform ink drop array on the polymer film obtained in the step (1) by using ink-jet printing ink, and naturally cooling after annealing treatment to obtain a uniform pattern array;

the polymer film in the step (1) is a polyvinylpyrrolidone film; the ink-jet printing ink in the step (2) is silver nanoparticle ink taking triethylene glycol ethyl ether as a solvent;

the temperature of the ink-jet printing in the step (2) is room temperature, and the ink drop distance is 150-250 mu m.

2. Use according to claim 1, characterized in that: the pretreatment in the step (1) is to sequentially use tetrahydrofuran, isopropanol, deionized water and isopropanol for ultrasonic cleaning, drying and then carrying out oxygen plasma treatment.

3. Use according to claim 1, characterized in that the polyvinylpyrrolidone film is prepared by the following process: spin-coating a polymer solution containing polymer PVP, curing agent methylated poly (melamine-co-formaldehyde) and solvent ethylene glycol on the pretreated glass substrate, and curing by ultraviolet light to obtain the polyvinylpyrrolidone film.

4. Use according to claim 1, characterized in that: the temperature of the annealing treatment in the step (2) is 150-250 ℃, and the time is 10 min.

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