KR102307114B1 - Amorphous metal flake, conductive inks comprising the same and method of manufacturing the same - Google Patents

Abstract

The present invention relates to an amorphous metal flake, a conductive ink comprising the same, and a method for manufacturing the same, and to provide metal particles for a conductive ink excellent in electrical conductivity and oxidation resistance by using an inexpensive metal material. The present invention is _{represented by the formula of Al x} Ni _y Y _z Co _w , where x, y, z and w represent an atomic ratio, wherein the atomic ratio is 77.5≤x≤90.0, 1.0≤y≤ 7.0, 2.0≤z≤10.0, and 0.0≤w≤5.5 to provide an amorphous metal flake.

Description

Amorphous metal flake, conductive ink comprising same, and method for manufacturing the same

The present invention relates to a conductive ink, and more particularly, to an amorphous metal flake dispersed and used in the conductive ink, a conductive ink comprising the same, and a method for manufacturing the same.

In the electronics industry, including displays, a printing process that can replace the existing vacuum process is being developed for the purpose of improving productivity and reducing costs by enlarging products and simplifying processes.

For this purpose, conductive ink using metal particles is being developed, and various types of metal particles such as spherical shape, flake, wire, and dendrite are used depending on the purpose.

Metal particles used in conductive inks are required to have excellent electrical conductivity and stable chemical properties in which oxidation does not occur in the dispersion environment and process conditions in the ink.

For this reason, silver, which exhibits superior physical properties compared to other materials, is widely used. However, when silver, which is an expensive material, is used, the product cost increases.

If aluminum particles with excellent conductivity and easy manufacture are used, the unit price of the product can be lowered, but oxidation reaction proceeds easily in air or in solution, and problems such as a high firing temperature and a decrease in electrical properties during sintering occur. do.

In order to overcome this, core-shell type particles in which a material having excellent conductivity such as copper or aluminum is coated with silver has also been developed, but the manufacturing process is complicated.

Therefore, it is necessary to solve the problems of existing materials by developing a material that is composed of inexpensive metal elements and has excellent oxidation resistance.

Registered Patent No. 10-1655365 (2016.09.07. Announcement)

Accordingly, an object of the present invention is to provide an amorphous metal flake composed of inexpensive metal elements and having excellent electrical conductivity and oxidation resistance, a conductive ink including the same, and a method for manufacturing the same.

In order to achieve the above object, the present invention is _{represented by the formula of Al x} Ni _y Y _z Co _w , where x, y, z and w represent an atomic ratio, and the atomic ratio is 77.5≤x An amorphous metal flake having ≤90.0, 1.0≤y≤7.0, 2.0≤z≤10.0 and 0.0≤w≤5.5 is provided.

The amorphous metal flakes have a thickness of 100 nm to 1000 nm.

The present invention is also _{represented by the formula of Al x} Ni _y Y _z Co _w , where x, y, z and w represent an atomic ratio, wherein the atomic ratio is 77.5≤x≤90.0, 1.0≤ Provided is a conductive ink comprising amorphous metal flakes having y≤7.0, 2.0≤z≤10.0, and 0.0≤w≤5.5.

The present invention is also _{represented by the formula of Al x} Ni _y Y _z Co _w , where x, y, z and w represent an atomic ratio, wherein the atomic ratio is 77.5≤x≤90.0, 1.0≤ forming an amorphous metal thin film on a base substrate by sputtering using an amorphous aluminum alloy target having y≤7.0, 2.0≤z≤10.0, and 0.0≤w≤5.5; and separating the amorphous metal thin film from the base substrate.

The forming of the amorphous metal thin film may include preparing an amorphous aluminum alloy powder having the composition of the formula; and preparing an amorphous aluminum alloy target for sputtering by agglomerating the amorphous aluminum alloy powder.

In the step of preparing the amorphous aluminum alloy powder, raw materials having the atomic ratio of the above formula are put into an atomizer, melted, and then pulverized to prepare an amorphous aluminum alloy powder.

The forming of the amorphous metal thin film may include: forming a sacrificial film made of a plastic material on the base substrate; and forming an amorphous metal thin film on the sacrificial film by sputtering using the aluminum alloy target.

In the separating step, the amorphous metal thin film may be separated from the sacrificial film.

The method for manufacturing amorphous metal flakes according to the present invention may further include a step of pulverizing the separated amorphous metal thin film, which is performed after the separation step, to prepare the amorphous metal flakes.

In the manufacturing step, the separated amorphous metal thin film may be pulverized through ultrasonic treatment.

The forming of the amorphous metal thin film may include: forming a sacrificial film made of a plastic material on the base substrate; forming a photoresist pattern on the sacrificial layer; and forming an amorphous metal thin film on the photosensitive film pattern by sputtering using the aluminum alloy target.

The size of the photoresist pattern corresponds to the size of the amorphous metal flake to be manufactured.

And in the separating step, the amorphous metal thin film on the photosensitive film pattern is obtained as an amorphous metal flake while removing the photosensitive film pattern.

According to the present invention, by manufacturing an aluminum-based alloy material into an amorphous phase flake, it is possible to provide excellent oxidation resistance while excluding precious metals such as silver and gold. That is, the amorphous metal flake according to the present invention is an alloy material containing Y, Co, or Ni as a main component of aluminum, and has an amorphous phase without crystallinity that existing metals have, so it is an aluminum-based material, but excellent It can provide oxidation resistance.

In addition, the conductive ink including the amorphous metal flakes according to the present invention can provide excellent electrical conductivity even after printing because the amorphous metal flakes do not oxidize even in a dispersed environment and high temperature process conditions in the conductive ink. That is, since the amorphous metal flake according to the present invention contains aluminum as a main component, but has excellent oxidation resistance, the process can be stably performed without a separate coating process on the outside of the amorphous metal flake, and a metal exhibiting excellent electrical conductivity Conductive inks capable of printing thin films can be prepared.

1 is a flowchart according to a first example of a method for manufacturing an amorphous metal flake according to the present invention.
2 to 6 are views showing each step according to the manufacturing method of FIG. 1 .
7 is a flowchart according to a second example of a method for manufacturing an amorphous metal flake according to the present invention.
8 is a graph showing XRD analysis results for each thickness of an aluminum-based amorphous metal thin film manufactured by a sputtering process.
9 is a graph showing an XRD analysis result of an aluminum-based crystalline metal thin film.
10 is a graph showing an XRD analysis result of an aluminum thin film.
11 is a photograph showing the results of comparative evaluation of oxidation resistance of metal thin films according to Comparative Examples and Examples.
12 is an SEM photograph of an amorphous metal flake according to an embodiment.
13 is a photograph showing the results of HRTEM and SADP analysis of amorphous metal flakes according to Examples.

It should be noted that, in the following description, only parts necessary for understanding the embodiments of the present invention are described, and descriptions of other parts will be omitted without departing from the gist of the present invention.

The terms or words used in the present specification and claims described below should not be construed as being limited to their ordinary or dictionary meanings, and the inventors have appropriate concepts of terms in order to best describe their inventions. It should be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined in Accordingly, the embodiments described in this specification and the configurations shown in the drawings are only preferred embodiments of the present invention, and do not represent all of the technical spirit of the present invention, so various equivalents that can be substituted for them at the time of the present application It should be understood that there may be variations and variations.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

The amorphous metal flake according to the present invention is a flake-type metal particle having amorphous properties based on aluminum, and may be used as a material for conductive ink.

The amorphous metal flakes according to the present invention may be manufactured by forming an amorphous metal thin film by configuring the composition so that the amorphous aluminum alloy has the characteristics of an amorphous phase, and then flakes the amorphous metal thin film.

First, when aluminum is alloyed with Ni, Y, and Co in a specific composition range, it exhibits an amorphous phase characteristic, and for this reason, an amorphous amorphous aluminum alloy has properties that do not appear in general crystalline metals. That is, the amorphous aluminum alloy according to the present invention has excellent oxidation resistance because the growth of the oxide film is suppressed due to the absence of grain boundaries.

The amorphous aluminum alloy according to the present invention is represented by the following Chemical Formula 1, in which x, y, z and w represent an atomic ratio, and the atomic ratio is 77.5≤x≤90.0, 1.0≤y≤7.0, 2.0≤z≤10.0 and 0.0≤w≤5.5.

[Formula 1]

Al _x Ni _y Y _z Co _w

The amorphous metal flake according to the present invention manufactured based on the amorphous aluminum alloy may provide excellent oxidation resistance while excluding precious metals such as silver and gold. That is, the amorphous metal flake according to the present invention is an alloy material containing Ni, Y or Co with aluminum as a main component, and has an amorphous phase without crystallinity that existing metals have. It can provide oxidizing properties.

In addition, the conductive ink including the amorphous metal flakes according to the present invention can provide excellent electrical conductivity even after printing because the amorphous metal flakes do not oxidize even in a dispersed environment and high temperature process conditions in the conductive ink. That is, since the amorphous metal flake according to the present invention has excellent oxidation resistance, the process can be stably performed without a separate coating process on the outside of the amorphous metal flake, and a metal thin film exhibiting excellent electrical conductivity can be printed. ink can be produced.

[Method for producing amorphous metal flakes]

The method for manufacturing the amorphous metal flake according to the present invention will be described with reference to FIGS. 1 to 7 as follows.

[First Example of Manufacturing Method]

1 is a flowchart according to a first example of a method for manufacturing an amorphous metal flake according to the present invention. 2 to 6 are views showing each step according to the manufacturing method of FIG. 1 .

1 to 6 , in the first example, an amorphous metal flake 80 is manufactured using a photoresist pattern 50 .

First, an amorphous aluminum alloy powder having a composition represented by Chemical Formula 1 is prepared in step S11. That is, raw materials having the atomic ratio of Formula 1 are put into an atomizer, melted, and then pulverized to prepare an amorphous aluminum alloy powder.

Next, the amorphous aluminum alloy powder is aggregated in step S13 to prepare an amorphous aluminum alloy target for sputtering. That is, the amorphous aluminum alloy powder is put into a container for producing a target, and then the amorphous aluminum alloy target for sputtering is prepared by applying pressure to the agglomerate.

Next, as shown in FIG. 2 , a sacrificial layer 20 is formed on the base substrate 10 in step S15 . That is, the sacrificial film 20 is formed on the base substrate 10 so that the amorphous metal thin film to be formed by sputtering on the base substrate 10 can be easily separated from the photosensitive film 30 .

A glass substrate, a plastic substrate, or a ceramic substrate may be used as the base substrate 10 . Materials of the plastic substrate include polyimide, polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate (polyethyelenen napthalate; PEN), polyethylene Polyethyeleneterepthalate (PET), polyphenylene sulfide (PPS), polyallylate, polycarbonate (PC), cellulose triacetate (CTA) or cellulose acetate propinonate; CAP) may be used, but not limited to those listed.

As a material of the sacrificial film 20 , a polymer that is easily soluble in a solvent may be used. For example, PMMA may be used as the sacrificial layer 20 , but is not limited thereto. As the solvent, a solvent capable of simultaneously removing the sacrificial layer 20 and the photosensitive layer 30 may be used.

Next, as shown in FIGS. 2 to 4 , a photoresist pattern 50 is formed on the sacrificial layer 20 in step S17 . That is, as shown in FIG. 2 , a photoresist is applied on the sacrificial layer 20 to form the photosensitive layer 30 . Then, as shown in FIGS. 2 and 3 , exposure is performed on the photosensitive film 30 using the mask 40 . And as shown in FIGS. 3 and 4 , a photoresist layer pattern 50 is formed by developing the exposed photoresist layer 30 . A sacrificial film pattern 60 corresponding to the photoresist pattern 50 is formed using the photoresist pattern 50 . At this time, the photoresist layer 30 in the exposed region and the sacrificial layer 20 thereunder are removed together through the developing process to form the photoresist layer pattern 50 and the sacrificial layer pattern 60 .

In this case, the size of the photoresist pattern 50 is formed to correspond to the size of the amorphous metal flake to be manufactured. Accordingly, the size of the amorphous metal flake to be manufactured can be adjusted through patterning of the photosensitive film 30 .

Next, as shown in FIG. 5 , an amorphous metal thin film 70 is formed on the photosensitive film pattern 50 by sputtering using an amorphous aluminum alloy target in step S19 . In this case, the amorphous metal thin film 70 may be deposited on the photoresist pattern 50 and on the base substrate 10 exposed between the photoresist patterns 50 .

5 and 6 , the amorphous metal thin film 70 may be separated by removing the photoresist pattern 50 in step S21 . That is, by dissolving the photoresist pattern 50 with a solvent, the amorphous metal thin film 70 on the photoresist pattern 50 can be easily separated. The separated amorphous metal thin film 70 is an amorphous metal flake 80 .

[Second Example of Manufacturing Method]

Meanwhile, in the first example, an amorphous metal flake was manufactured using a photoresist pattern, but the present invention is not limited thereto. For example, as shown in FIG. 7 , an amorphous metal flake may be manufactured through pulverization without using a photoresist pattern.

7 is a flowchart according to a second example of a method for manufacturing an amorphous metal flake according to the present invention.

Referring to FIG. 7 , in the method for manufacturing an amorphous metal flake according to the second example, steps S11 to S15 are performed in the same manner as in the first example.

Next, an amorphous metal thin film is formed by sputtering using an amorphous aluminum alloy target on the sacrificial film in step S18. In this case, the amorphous metal thin film is formed on the entire surface of the sacrificial film.

Then, in step S20, the amorphous metal thin film is separated from the sacrificial film. That is, by dissolving and removing the sacrificial film with a solvent, the amorphous metal thin film can be separated from the base substrate. For example, when the base substrate on which the amorphous metal thin film is formed is put into a solution tank containing a solvent capable of dissolving the sacrificial film, the sacrificial film is dissolved by the solvent. Due to this, the amorphous metal thin film is separated from the base substrate.

And by pulverizing the amorphous metal thin film separated in step S22, the amorphous metal flake according to the present invention can be obtained. At this time, the separated amorphous metal thin film may be pulverized through ultrasonic treatment, and the obtained amorphous metal flakes have random sizes and shapes.

That is, since the amorphous metal plate manufactured by the manufacturing method of the first example is manufactured using the photoresist pattern, it can be manufactured in a standardized size and shape.

On the other hand, since the amorphous metal flake manufactured by the manufacturing method of the second example is manufactured by pulverizing a wide amorphous metal thin film, it can be manufactured in a random size and shape.

The amorphous metal flakes prepared in this way can be used as a material for conductive ink.

[Examples and Comparative Examples]

In order to confirm the oxidation resistance and electrical conductivity of the amorphous metal flake manufactured by the manufacturing method of the present invention, an amorphous metal thin film and an amorphous metal flake were prepared by the manufacturing method of the second example.

In an embodiment, an amorphous aluminum alloy target for sputtering was prepared using an amorphous aluminum alloy having an atomic ratio of x=85, y=5, z=8, and w=2 in Chemical Formula 1. A glass substrate was used as the base substrate, and PMMA was used as the sacrificial film.

[Comparative evaluation of amorphous phase]

First, the amorphousness according to the thickness of the metal thin film formed on the base substrate by the sputtering process was confirmed.

8 is a graph showing XRD analysis results for each thickness of an aluminum-based amorphous metal thin film manufactured by a sputtering process.

Referring to FIG. 8 , a metal thin film was deposited to a thickness of 100 nm, 300 nm, 500 nm, and 1000 nm by sputtering using the amorphous aluminum alloy target according to the embodiment on the sacrificial film of the base substrate.

As a result of XRD analysis, it was confirmed that the metal thin film deposited on the base substrate at a thickness of 100 nm to 1000 nm was an amorphous metal thin film exhibiting an amorphous phase.

For example, when the deposited metal thin film is not formed in an amorphous phase due to a problem in composition or process but is formed in a crystalline phase, a diffraction pattern appears as shown in FIGS. 9 and 10 . 9 is a graph showing the XRD analysis result of the aluminum-based crystalline metal thin film. And FIG. 10 is a graph showing the XRD analysis result of the aluminum thin film.

Comparing the XRD analysis results of FIGS. 8 to 10 , it can be seen that the metal thin film according to the embodiment exhibits an amorphous phase characteristic.

[Comparative evaluation of oxidation resistance]

In order to compare and evaluate the oxidation resistance of the crystalline aluminum thin film according to the comparative example and the 100 nm thick amorphous metal thin film according to the embodiment, the change in sheet resistance after exposure to a high temperature and high humidity environment was measured.

11 is a photograph showing the results of comparative evaluation of oxidation resistance of metal thin films according to Comparative Examples and Examples.

Referring to (a) of FIG. 11 , the crystalline aluminum thin film according to the comparative example is rapidly oxidized after 2 hours, and it can be seen that most of the thin film is oxidized or lost after 8 hours.

Referring to (b) of FIG. 11 , in the amorphous metal thin film according to the embodiment, although oxidation occurred in a local part, it was confirmed that the corresponding part did not grow and the oxidation process stopped.

0h 2h 4h 6h 8h comparative example 1.79 3.54 4.42 5.46 487
(271% increase) Example 7.06 7.39 8.23 9.89 10.07
(42.6% increase)

As shown in Table 1, it can be seen that the increase in sheet resistance of the crystalline aluminum thin film according to the comparative example rapidly increased to 271% after 8 hours.

On the other hand, in the case of the amorphous metal thin film according to the embodiment, even after 8 hours, it can be confirmed that the increase in sheet resistance is very low at 10.07%.

As such, it can be confirmed that the amorphous metal thin film according to the embodiment has excellent oxidation resistance.

[Check flake shape]

The amorphous metal thin film according to the embodiment was prepared by the manufacturing method according to the second example to prepare an amorphous metal flake.

12 is an SEM photograph of an amorphous metal flake according to an embodiment. And FIG. 13 is a photograph showing the analysis results of HRTEM (High-Resolution Transition Electron Microscopy) and SADP (Selected Area Diffraction Patterns) of the amorphous metal flake according to the embodiment.

12 and 13 , it can be easily confirmed that the amorphous metal flakes according to the embodiment are prepared in a random shape.

It can be seen that the amorphous metal flake according to the embodiment exhibits an amorphous SADP without a periodic lattice fringe in HRTEM.

On the other hand, the embodiments disclosed in the present specification and drawings are merely presented as specific examples to aid understanding, and are not intended to limit the scope of the present invention. It is apparent to those of ordinary skill in the art to which the present invention pertains that other modifications based on the technical spirit of the present invention can be implemented in addition to the embodiments disclosed herein.

10: base substrate
20: sacrificial curtain
30: photosensitive film
40: mask
50: photosensitive film pattern
60: sacrificial film pattern
70: amorphous metal thin film
80: amorphous metal flake

Claims (14)

delete delete delete delete forming a sacrificial film made of a plastic material on the base substrate;
It _{is represented by the formula of Al x} Ni _y Y _z Co _w , where x, y, z and w represent an atomic ratio, wherein the atomic ratio is 77.5≤x≤90.0, 1.0≤y≤7.0, 2.0 forming an amorphous metal thin film on the sacrificial film by sputtering using an amorphous aluminum alloy target of ≤z≤10.0 and 0.0≤w≤5.5; and
separating the amorphous metal thin film from the sacrificial film;
A method for producing amorphous metal flakes comprising a. 6. The method of claim 5,
The amorphous metal thin film is a method of manufacturing an amorphous metal flake, characterized in that the thickness of 100nm to 1000nm. The method of claim 5, wherein the forming of the amorphous metal thin film comprises:
Preparing an amorphous aluminum alloy powder having the composition of the formula; and
preparing an amorphous aluminum alloy target for sputtering by agglomerating the amorphous aluminum alloy powder;
A method for producing an amorphous metal flake comprising a. According to claim 7, In the step of preparing the amorphous aluminum alloy powder,
A method of manufacturing an amorphous metal flake, characterized in that the raw materials having the atomic ratio of the chemical formula are put into an atomizer, melted, and then pulverized to prepare an amorphous aluminum alloy powder. delete 8. The method of claim 7, which is performed after the step of separating,
pulverizing the separated amorphous metal thin film to prepare an amorphous metal flake;
Method for producing amorphous metal flakes, characterized in that it further comprises. The method of claim 10, wherein in the manufacturing step,
Method for producing amorphous metal flakes, characterized in that the separated amorphous metal thin film is pulverized through ultrasonic treatment. The method of claim 7, which is performed after the step of forming the sacrificial film.
Forming a photoresist pattern on the sacrificial film; further comprising,
In the step of forming the amorphous metal thin film, the method for manufacturing an amorphous metal flake, characterized in that forming the amorphous metal thin film by sputtering using the aluminum alloy target on the photosensitive film pattern. 13. The method of claim 12,
The method of manufacturing an amorphous metal flake, characterized in that the size of the photoresist pattern corresponds to the size of the amorphous metal flake to be manufactured. The method of claim 13, wherein in the separating step,
A method of manufacturing an amorphous metal flake, characterized in that while removing the photoresist pattern, the amorphous metal thin film on the photoresist pattern is obtained as an amorphous metal flake.

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