KR20180001786A - Method for coating phosphor using dry type surface treatment - Google Patents

Abstract

An objective of the present invention is to provide a phosphor coating method using dry surface treatment, capable of improving dispersibility between phosphors and providing improved luminous efficiency by coating the surface of a phosphor through plasma generation using a surface modifying material and a discharge gas. To achieve this, the phosphor coating method comprises: a) a step of injecting a phosphor, a surface modifying material, and a discharge gas into a chamber; and b) a step of allowing a high voltage generating unit to discharge a voltage inside the chamber to generate plasma through the discharge gas, and allowing the generated plasma to scatter the phosphor through physical energy by electromagnetic energy and plasma ions to deposit the surface modifying material on the surface of the phosphor. Therefore, it is possible to improve dispersibility between the phosphors and to enhance luminous efficiency by coating the surface of the phosphor through plasma generation using the surface modifying material and the discharge gas, and to shorten the manufacturing processes as compared with a wet phosphor coating process by improving an additional post-treatment heat process.

Description

TECHNICAL FIELD [0001] The present invention relates to a phosphor coating method using a dry surface treatment,

The present invention relates to a phosphor coating method using a dry surface treatment, and more particularly, to a phosphor coating method using a surface treatment of a phosphor by coating a surface of the phosphor with a surface modification material and a discharge gas to improve dispersibility between the phosphors, To a phosphor coating method using a dry surface treatment.

BACKGROUND ART [0002] Generally, phosphors have been used for a display device such as a light source such as a fluorescent lamp and a copying lamp, an electroluminescent device, a plasma display or the like, or a detecting device.

Various methods have been attempted to obtain such a phosphor having deterioration characteristics, luminance, color purity, and afterglow characteristics suitable for application fields.

Particularly, the phosphor has poor chemical stability due to moisture during the use period, and the initial light characteristic is deteriorated due to heat generated in the apparatus, resulting in a serious change in luminance and chromaticity coordinates.

In order to solve such a problem, a method of coating a silicon compound on the surface of a phosphor has been proposed.

A conventional method of forming a silicon compound coating layer is to coat a silicon compound on the surface of a phosphor by using a base catalyst or a sol-gel process of TEOS (tetraethylorthosilicate) in amine and ethanol.

Korean Patent Laid-Open Publication No. 10-2009-0010538 (the name of the invention: phosphor for light-emitting diode and its surface coating method) and Korean Patent Laid-Open Publication No. 10-2014-0056406 Coating method) discloses a method of coating a phosphor surface.

FIG. 1 is a flow chart illustrating a coating process of a phosphor surface according to the related art. In the coating process of the conventional phosphor surface, the phosphor is immersed in an aqueous solution containing ammonium phosphate (S1) (S2) for 2 hours to 24 hours in a temperature environment of < 0 > C to 550 < 0 > C, and washing the heat-treated phosphor (S3).

However, in the conventional method of coating a phosphor, since a phosphor is immersed in a solution containing deionized water or the like to coat a surface of a phosphor and then a coating layer is formed through a chemical reaction, a phosphor such as a halide is efficiently There is a problem that only a fluorescent light body which is not sensitive to a liquid solvent such as moisture or alcohol is deteriorated.

Document 1: Korean Patent Laid-Open Publication No. 10-2009-0010538 (Title of Invention: phosphor for light-emitting diode and surface coating method thereof) Document 2: Korean Patent Laid-Open Publication No. 10-2014-0056406 (title of the invention: phosphor surface coating method)

In order to solve these problems, the present invention provides a phosphor coating method using a dry surface treatment in which the surface of a phosphor is coated by plasma generation using a surface modifying material and a discharge gas to improve the dispersibility between the phosphors and improve the luminous efficiency The purpose is to provide.

According to an aspect of the present invention, there is provided a phosphor coating method comprising the steps of: a) injecting a phosphor, a surface modifying material and a discharge gas into a chamber; And b) a high voltage generating unit discharges a voltage in the chamber to generate a plasma through the discharge gas, and the generated plasma disperses the phosphor through electromagnetic energy and physical energy by plasma ions, And depositing a surface modifying material on the surface.

In addition, the step a) according to the present invention may further include heating the injected surface modifying material so as to promote vaporization.

In addition, the heating step according to the present invention is characterized in that the heating is performed at a temperature ranging from 150 ° C to 200 ° C.

The phosphor according to the present invention is characterized in that it is at least one of halide, lutetium aluminum (LuAG), silicate, nitride and YAG.

Also, the surface modification material according to the present invention is characterized by being HDTMS (Hexadecyl trimethoxy silane).

Further, the plasma of step b) according to the present invention is characterized by being generated for at least 20 minutes or more.

Further, the phosphor according to the present invention is characterized in that it has at least one property of hydrophilicity and hydrophobicity depending on the carbon length of the -OH group or the surface modifying material on the phosphor surface.

The present invention has the advantage of improving the dispersibility between phosphors and improving the luminous efficiency by coating the surface of the phosphor through plasma generation using a surface modifying material and a discharge gas.

Further, the present invention has an advantage in that the manufacturing process can be shortened in comparison with the phosphor coating process using a wet process, by further improving the post-treatment thermal process.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart illustrating a coating process of a phosphor surface according to the prior art; FIG.
2 is a flow chart illustrating a method of coating a phosphor using a dry surface treatment according to the present invention.
3 is a view illustrating a phosphor coating process using a dry surface treatment according to the present invention.
4 is a view illustrating contact angle of ultrapure water in a phosphor coating process using a dry surface treatment according to the present invention.
FIG. 5 is a graph showing changes in light emitting performance of a phosphor after phosphor coating treatment using a dry surface treatment according to the present invention. FIG.
FIG. 6 is a graph showing changes in pH by measuring the moisture blocking effect of the phosphor after the phosphor coating treatment using the dry surface treatment according to the present invention. FIG.
FIG. 7 is a graph showing the luminous efficiency of a phosphor of an LED package to which a phosphor coated with a phosphor by using a dry surface treatment according to the present invention is applied.

Hereinafter, preferred embodiments of the phosphor coating method using the dry surface treatment according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a flow chart showing a method of coating a phosphor using a dry surface treatment according to the present invention, and FIG. 3 is a view illustrating a process of coating a phosphor using a dry surface treatment according to the present invention.

2 and 3, the phosphor coating method according to the present invention generates a plasma 130 in a space where the phosphor 100, the surface modifying material 110, and the discharge gas 120 are injected, And the surface modification material 110 is deposited on the surface of the phosphor 100 by coating the phosphor 100 with the physical energy by the energy and the plasma ion scattering the phosphor 100. As a result, The high voltage generating unit 210 discharges a voltage in the chamber 200 and supplies the plasma 130 to the discharge gas 120 through the discharge gas 120. [ And the generated plasma 130 disperses the phosphor 100 through electromagnetic energy and physical energy by plasma ions to deposit the surface modifying material 110 on the surface of the phosphor 100 Step S110.

In step S100, the phosphor 100 is introduced into the chamber 200 having the predetermined space, the surface modifying material 110 to be deposited on the surface of the phosphor 100, and the discharge gas (Not shown).

The phosphor 100 may be a halide phosphor, but is not limited thereto. Various phosphors such as lutetium aluminum (LuAG), silicate, nitride, and YAG may be used.

In addition, since the white LED can be manufactured using two or more kinds of phosphors, the dispersibility among the phosphors mixed in the silicon determines the efficiency.

The phosphor 100 may be configured to maintain at least one of hydrophilicity and hydrophobicity according to the carbon length of the -OH group or the surface modifying material 110 on the phosphor surface to treat the phosphors having different surface characteristics with various materials, So that the dispersibility between the phosphors can be improved.

The surface modifying material 110 is made of Hexadecyl trimethoxy silane (HDTMS). The surface modifying material 110 may be a surface modifying material having a different carbon length, for example, propyl trimethoxy silane, 3-aminopropyl triethoxy silane , hexyl trimethoxysilane, and the like.

In addition, in step S100, the injected surface modifying material 110 may be additionally configured to be heated so as to promote vaporization since it exists in a liquid state.

In the step of heating the surface modifying material 110, the heated temperature is preferably in the range of 150 ° C to 200 ° C.

When a high voltage is generated in the discharge gas 120, any gas capable of generating a plasma such as argon, nitrogen, or oxygen can be used as the gas generating the plasma. Preferably, argon gas is used.

In step S110, the high voltage generating unit 210 applies a high voltage to the inside of the chamber 200 to discharge the plasma 130, thereby generating the plasma 130 through the discharge gas 120.

That is, when a high voltage is generated in the space where the surface modifying material 110 and the discharge gas are present, a plasma 130 is generated, and the generated plasma 130 is irradiated with the electromagnetic wave energy and the physical energy by the plasma ion 100).

The phosphor 100 is scattered in the air by the applied energy and the surface modifying material 110 is deposited on the surface of the phosphor to uniformly coat the surface modifying material 110 on the entire surface of the phosphor 100 .

The plasma 130 in step S110 is generated for at least 20 minutes so that the surface of the phosphor 100 is uniformly coated.

4 (a) and 4 (b) are graphs showing the contact angle using ultrapure water in the phosphor coating process using the dry surface treatment according to the present invention. In the case of the phosphor having hydrophobicity, 4 (b), and the contact angle measured after a lapse of a certain time (for example, 1 hour, 30 minutes, 4 days) after the coating treatment in order to confirm the maintenance of the effect, As shown in FIG. 4 (d), the surface modification material maintains 121.4 and 125.2 degrees, indicating that the surface modification material is not simply physically present on the surface but is chemically bonded.

FIG. 5 is a graph showing changes in the light emission performance of the phosphor after the phosphor coating treatment using the dry surface treatment according to the present invention. It can be seen that there is no change in the light emitting performance even after coating the surface, It can be seen that it exists in the form of molecules of several nanometers in size on the surface and does not affect the luminescence of the phosphor.

FIG. 6 is a graph showing changes in pH by measuring the water-blocking effect of the phosphor after the phosphor coating treatment using the dry surface treatment according to the present invention, wherein the pH is 3.5 or less While the hydrophobic halide phosphors have a pH of 3.5, which is longer than 100 seconds.

This is because the surface of the halide phosphor is hydrophobic and blocks the contact between the phosphor and moisture to retard the decomposition of the phosphor by moisture. Such a moisture-blocking effect is attributed to the fact that the life of the halide phosphor Can be greatly improved.

FIG. 7 is a graph showing the luminous efficiency of the phosphor of the LED package to which the phosphor-coated phosphor using the dry-type surface treatment according to the present invention is applied, wherein the emission of the LED package manufactured using the hydrophobic phosphor is increased by about 10% .

These results show that the surface of the halide phosphor has hydrophobicity and dispersibility in the silicon mixed with the phosphor is improved. Thus, the improvement of the dispersibility of the phosphor in the silicon can increase the efficiency of the phosphor emitting light by absorbing light .

That is, when the dispersibility is high, the portion where the phosphor does not exist is reduced, and the light output from the chip in the absence of the phosphor is prevented from being emitted as it is, and most of the light emitted from the chip is absorbed by the phosphor Since the phosphor emits light, more light can be output and the light emission efficiency can be increased.

Therefore, it is possible to improve the dispersibility between the phosphors and improve the luminous efficiency by coating the surface of the phosphor through plasma generation using the surface modifying material and the discharge gas. It is also possible to improve the luminous efficiency, By improving the post-treatment process, the manufacturing process and time can be greatly shortened compared with the phosphor coating process using a wet process.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims. It can be understood that

In the course of the description of the embodiments of the present invention, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation, , Which may vary depending on the intentions or customs of the user, the operator, and the interpretation of such terms should be based on the contents throughout this specification.

100: phosphor
110: Surface modifying material
120: discharge gas
130: Plasma
200: chamber
210: High voltage generator

Claims (7)

a) injecting the phosphor 100, the surface modifying material 110 and the discharge gas 120 into the chamber 200; And
b) a high voltage generating unit 210 generates a plasma 130 through the discharge gas 120 by discharging a voltage into the chamber 200, and the generated plasma 130 generates electromagnetic energy and plasma And depositing the surface modifying material (110) on the surface of the phosphor (100) by scattering the phosphor (100) through physical energy by the ion.
The method according to claim 1,
Wherein the step a) further comprises heating the injected surface modifying material (110) so as to promote vaporization.
3. The method of claim 2,
Wherein the heating step is performed at a temperature in the range of 150 ° C to 200 ° C.
The method of claim 3,
Wherein the phosphor 100 is at least one of halide, lutetium aluminum (LuAG), silicate, nitride, and YAG.
5. The method of claim 4,
Wherein the surface modifying material (110) is Hexadecyl trimethoxy silane (HDTMS).
6. The method of claim 5,
Wherein the plasma 130 in step b) is generated for at least 20 minutes or more.
The method according to claim 6,
Wherein the phosphor (100) maintains at least one of hydrophilicity and hydrophobicity according to the carbon length of the -OH group or the surface modifying material on the phosphor surface.

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