KR102584893B1 - Glass Frit Composition Including a Phosphor and Method for Manufacturing the Same - Google Patents

Abstract

Disclosed is a glass frit composition containing a phosphor and a method for manufacturing the same.
According to one embodiment of the present invention, 50 to 68 parts by weight of an oxide mixture consisting of silicon oxide (SiO ₂ ), boron oxide (B ₂ O ₃ ), zinc oxide (ZnO), and aluminum oxide (Al ₂ O ₃ ). and 20 to 24 parts by weight of an alkali oxide containing an alkali metal and rare earth metals such as lanthanum oxide (La ₂ O ₃ ), niobium pentoxide (Nb ₂ O ₅ ), neodymium oxide (Nd ₂ O ₃ ), and europium oxide. A glass frit composition for a phosphor plate is provided, comprising 12 to 17 parts by weight of (Eu ₂ O ₃ ) and 0.1 to 3 parts by weight of metal oxide powder.

Description

Glass frit composition including a phosphor and method for manufacturing the same {Glass Frit Composition Including a Phosphor and Method for Manufacturing the Same}

The present invention relates to a glass frit composition containing a ceramic phosphor and a method of manufacturing the same.

The content described in this section simply provides background information for this embodiment and does not constitute prior art.

White LEDs have received attention as high-efficiency, high-reliability white lighting sources, and some are already available for use as low-power, compact light sources. There are various ways to implement white LEDs, but the most commonly used method is to mold blue LED elements using a resin containing yellow phosphor as a matrix.

However, because blue light has strong energy, it is easy to deteriorate the resin. Therefore, when a white LED with this structure is used for a long period of time, the color of the light emitted changes because the resin discolors. In addition, since it is molded with resin, heat is not easily dissipated from the device, so the temperature is likely to rise. There is a problem in that the emission color shifts toward yellow due to this temperature.

To solve this problem, a phosphor plate using ceramic sintered body as a phosphor matrix material was applied. In the case of such inorganic materials, they are transparent, have great optical and aesthetic effects, and are highly chemically safe, allowing for a wide range of use environments. In addition, it has a wide variety of uses due to its advantages such as high mechanical hardness, good thermal stability, high electrical insulation, and no harm to the human body or the environment.

Meanwhile, the phosphor plate is a concept that includes Phosphor Ceramic Plate (PCP), Phosphor Glass Plate (PGP), Glass Phosphor Plate (GPP), Single-crystal Phosphor Plate (SCPP), and Phosphor-in-glass (PiG). It is used. Here, PiG, a glass material, is in the spotlight due to its excellent reliability.

The refractive index of PiG glass powder currently on the market is around 1.5, causing phosphor and light loss. In order to improve PiG efficiency, an increase in the refractive index of PiG Glass is required. In particular, the refractive index of the GaN layer of the LED chip is 2.1. The higher the refractive index of the phosphor film, the better the refractive index matching with the light-emitting GaN layer, increasing the light extraction efficiency, and the refractive index of the YAG phosphor is 1.71. Because scattering occurs inside the fluorescent film due to the difference in refractive index between 1.4 and 1.5 of the encapsulant, a glass encapsulant with the same refractive index as the phosphor is required.

One embodiment of the present invention has the purpose of providing a glass frit composition that contains a phosphor, is resistant to heat, and can reduce ground backscattering of blue light consumption, and a method of manufacturing the same.

According to one aspect of the present embodiment, 50 to 68 parts by weight of an oxide mixture consisting of silicon oxide (SiO ₂ ), boron oxide (B ₂ O ₃ ), zinc oxide (ZnO), and aluminum oxide (Al ₂ O ₃ ) and 20 to 24 parts by weight of an alkali oxide containing an alkali metal and rare earth metals such as lanthanum oxide (La ₂ O ₃ ), niobium pentoxide (Nb ₂ O ₅ ), neodymium oxide (Nd ₂ O ₃ ), and europium oxide ( Provided is a glass frit composition for a phosphor plate, comprising 12 to 17 parts by weight of Eu ₂ O ₃ ) and 0.1 to 3 parts by weight of metal oxide powder.

As described above, according to one aspect of the present invention, the glass frit composition has excellent chemical stability and environmental stability, and has the advantage of good back scattering to reduce refractive index matching.

Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention. While describing each drawing, similar reference numerals are used for similar components.

Terms such as first, second, A, and B may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be named a second component, and similarly, the second component may also be named a first component without departing from the scope of the present invention. The term and/or includes any of a plurality of related stated items or a combination of a plurality of related stated items.

When a component is said to be "connected" or "connected" to another component, it is understood that it may be directly connected to or connected to the other component, but that other components may exist in between. It should be. On the other hand, when it is mentioned that a component is “directly connected” or “directly connected” to another component, it should be understood that there are no other components in between.

The terms used in this application are only used to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "include" or "have" should be understood as not precluding the existence or addition possibility of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification. .

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person of ordinary skill in the technical field to which the present invention pertains.

Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless explicitly defined in the present application, should not be interpreted in an ideal or excessively formal sense. No.

Additionally, each configuration, process, process, or method included in each embodiment of the present invention may be shared within the scope of not being technically contradictory to each other.

The glass composition for a high refractive index ceramic phosphor plate according to this embodiment is an oxide mixture consisting of silicon oxide (SiO ₂ ), boron oxide (B ₂ O ₃ ), zinc oxide (ZnO), and aluminum oxide (Al ₂ O ₃ ). to 68 parts by weight, 20 to 24 parts by weight of an alkali oxide containing an alkali metal, 12 to 17 parts by weight of a rare earth metal oxide, and 0.1 to 3 parts by weight of metal oxide nanopowder.

An oxide mixture consisting of silicon oxide (SiO ₂ ), boron oxide (B ₂ O ₃ ), zinc oxide (ZnO), and aluminum oxide (Al ₂ O ₃ ) forms the most basic structure when producing glass by vitrifying the glass composition. Among the oxides that form glass, it belongs to the network former or network-forming oxide. The oxide mixture is the most basic component of glass, and three-component glass can be manufactured with this composition alone.

Boron oxide is a basic material needed to form glass, but when manufacturing a phosphor plate for forming a lighting device, as the content of boron oxide increases, there is a risk that optical characteristics such as reliability and light transmittance will be greatly reduced. In particular, it can act as a factor that most significantly affects the whitening phenomenon of the above-mentioned phosphor plate. It is more preferable that boron oxide is contained in less than 28 parts by weight.

Aluminum oxide combines with rare earth elements to improve mechanical and optical properties. By combining aluminum oxide and rare earth elements, a three-dimensional and continuously entangled composite material can be obtained, forming a matrix phase in which phosphors made of rare earth metal oxides can exist stably.

With reference to the above-mentioned characteristics, each component in the oxide mixture is contained in the following amounts. Zinc oxide (ZnO) is 8 to 12 parts by weight, aluminum oxide (Al ₂ O ₃ ) is 2 to 6 parts by weight, boron oxide (B ₂ O ₃ ) is 24 to 28 parts by weight, and silicon oxide (SiO ₂ ) is It contains 16 to 22 parts by weight. With this inclusion, a stable phosphor plate can be manufactured without deteriorating optical properties.

In order to lower the sintering temperature when manufacturing a phosphor plate, the glass transition temperature (Tg) of the glass frit that constitutes the matrix of the phosphor plate must be formed low. An oxide containing an alkali metal is included to lower the glass transition temperature (Tg).

Alkali metals include potassium (K), sodium (Na), and lithium (Li), and when manufacturing phosphor plates, alkali oxides include potassium oxide (K ₂ O), sodium oxide (Na ₂ O), and lithium oxide (Li ₂ O) is included. However, if the alkali metal component increases in the composition, there is a risk that the glass composition may not be released or the optical characteristics of the phosphor plate may be impaired, so it is preferable that the total content does not exceed 24 parts by weight.

Each component in alkali oxide is contained in the following amounts. Potassium oxide (K ₂ O) is included in an amount of 5 to 7 parts by weight, sodium oxide (Na ₂ O) is included in an amount of 7 to 8 parts by weight, and lithium oxide (Li ₂ O) is included in an amount of 8 to 9 parts by weight. As each component is included in this way, the glass transition temperature can be lowered without deteriorating optical properties.

The glass composition contains ingredients that increase the refractive index, including rare earth metal oxides such as lanthanum oxide (La ₂ O ₃ ), niobium pentoxide (Nb ₂ O ₅ ), neodymium oxide (Nd ₂ O ₃ ), and europium oxide (Eu ₂ O _{3 )} . ) is included in an amount of 12 to 17 parts by weight. Rare earth metal oxides act to increase the refractive index in glass.

In addition to the above-mentioned ingredients, metal oxide nano powder may be included. During the sintering process of the above-mentioned components, air is not released smoothly, which may cause problems such as the generation of bubbles. As the metal oxide is included in the above-mentioned components, the amount of air is reduced and the transparency of the phosphor plate to be manufactured is improved. However, since metal oxide is a highly reactive ingredient, it is included only in an amount of 0.1 to 3 parts by weight.

A ceramic phosphor plate according to another aspect of this embodiment uses a glass frit having an average particle diameter of 1 μm to 10 μm obtained by vitrifying the above-described glass composition as a matrix, and includes at least one type of phosphor.

The glass frit is an oxide mixture consisting of silicon oxide (SiO ₂ ), boron oxide (B ₂ O ₃ ), zinc oxide (ZnO), and aluminum oxide (Al ₂ O ₃ ) containing 50 to 68 parts by weight of an alkali metal. A composition containing 20 to 24 parts by weight of alkali oxide, 12 to 17 parts by weight of rare earth metal oxide, and 0.1 to 3 parts by weight of metal oxide nanopowder is mixed in a ball mill for 40 to 50 hours. After that, it is put into the melting furnace. It can be melted by adjusting the melting temperature depending on the composition of the glass composition. At this time, the melting temperature may be 1300°C to 1600°C, and the glass may be manufactured according to a conventional glass manufacturing process. The raw materials included in the glass composition are melted by selecting a temperature at which they can be homogeneously dissolved. At this time, if the temperature is increased beyond 1600°C, there is a risk that volatile components will increase. The melt is poured into a twin roll and quenched to prepare a glass cullet. Prepare glass frit by crushing the glass cullet.

There are two types of grinding methods, dry grinding and wet grinding, and dry grinding methods include ball mill and vibrating mill. Ceramic balls used in ball mills are generally made of aluminum oxide (Al ₂ O ₃ ) or zirconium oxide (ZrO ₂ ). Because vibrating mills use vibrating motion, the impact on the pulverized material is large. Wet grinding is a method of grinding by stirring the ground material and balls in a liquid. Compared to dry grinding, fine grinding is possible. In addition to ball mills, medium stirring mills and bead mills are used. A bead mill is a grinder that uses highly wear-resistant ceramic balls (Beads) with a diameter of 0.5 mm to 2.0 mm. The liquid used for wet grinding can be an organic solvent such as water or ethanol. For glass with high water resistance, water is mainly used, and if there is concern about changes in composition when using water, an organic solvent can be used.

The glass frit according to this embodiment may have an average particle diameter of 1㎛ to 10㎛, preferably 2㎛ to 7㎛. If the particle size of the glass frit is reduced, the internal porosity after sintering is reduced, which is advantageous for improving optical properties. If the particle size of the glass frit exceeds 10㎛, there is a risk that multiple pores may be formed when mixed with a phosphor and sintered later. On the other hand, if the particle size of the organic frit is less than 1㎛, there is a risk that it may not be sufficiently dispersed when mixed with the phosphor and thus may not be able to passivate the phosphor sufficiently. As the milling time increases, the degree of contamination also increases, making it difficult to maintain whiteness after sintering. It becomes difficult

The ceramic phosphor may be one of yellow, green, or red phosphors depending on the required optical characteristics, color of lighting, application field, etc., and may be two or more types of phosphors that excite light of different wavelengths as needed. Ceramic phosphors include Yttrium Aluminum Garnet (YAG), Lutetium Aluminum Garnet (LuAG), Nitride, Sulfide, or Silicate. You can use it.

The ceramic phosphor is mixed to 10 wt% to 20 wt% with respect to the glass frit. At this time, the amount of phosphor mixed may be slightly changed depending on the transmittance and color difference after sintering. In addition, the content of phosphor changes depending on the change in thickness, and when the thickness increases, a reduced amount of phosphor can be added.

The mixture of glass frit and the ceramic phosphor is put into a Stainless Use Steel (SUS) mold and uniaxially compressed so that it has a plate or disk shape. At this time, compression is performed at 7 tons for 5 minutes. The compressed mixture of the inorganic phosphor-glass powder is placed in a sintering furnace to perform sintering. At this time, the temperature and time for performing sintering can be adjusted according to the glass transition temperature (Tg) of the inorganic phosphor and glass powder.

The ceramic phosphor plate after completion of firing can be further subjected to surface polishing to adjust the thickness and surface roughness to suit the characteristics required in this embodiment. At this time, the ceramic phosphor plate is polished so that the thickness is 200㎛ to 1000㎛ and the surface roughness is 0.1㎛ to 0.3㎛.

The solid-state light emitting device may be any one selected from LED, OLED, LD (Laser Diode), Laser, and VCSEL. A ceramic phosphor plate 110 is provided at the upper end of the housing 130 and is arranged to be spaced apart from the light source 120. As described above, the ceramic phosphor plate 110 includes a matrix made of glass frit and ceramic phosphor dispersed in the matrix. The inside of the housing 132 may be filled with a material having a refractive index higher than or equal to that of the ceramic phosphor plate 110.

Additionally, optical properties can be measured using this type of integrating sphere. The internal luminance of the integrating sphere is constant at any angle, and all light reflected from the sample surface is captured and distributed at even illuminance on the surface of the integrating sphere. Coating materials for the inner wall of the integrating sphere include special paint or polytetrafluoroethylene (PTFE). Be careful not to contaminate the inside. In the case of spectral transmittance, the light transmitted without a sample is set at 100%, and the case where the light is completely blocked by an opaque object such as a steel plate is set at 0%. When the dispersion effect within the transmitting material is large among the transmitting colors, it is preferable to measure using an integrating sphere.

[Examples 1 to 3]

Ceramic glass compositions having the components shown in Table 1 below (glass frit compositions and produced glass properties according to examples) were first added and mixed, and then melted at a high temperature of 1300°C to 1600°C to prepare glass. . The produced glass was pulverized to prepare glass powder having an average particle diameter of 1 to 15㎛. The manufactured glass powder is put into a mold and compressed for 5 minutes at a pressure of 5 tons, then put into a furnace and fired at 650°C for 30 minutes, and then the mirror surface is abraded to achieve a surface roughness of 2㎛ with a thickness of 500㎛. A glass plate was manufactured by treating it with a mirror surface.

[Table 1]

As shown in Table 1, it can be confirmed that the glass powders according to Examples 1 to 3 have high transmittance and refractive index characteristics, and in terms of thermal characteristics, they have appropriate softening characteristics that can be fired below 700 ° C.

[Table 2]

The phosphor (Intermatics) was mixed with the glass frit powder prepared from the glass composition of Example 3 in a ball mill at the composition ratio shown in Table 3 below and thoroughly mixed. The mixture was put into a mold and compressed for 5 minutes under a pressure of 5 tons to obtain a compression molded product. The compression molded product was fired in a furnace at a temperature of 650°C for 40 minutes, and then mirror-processed to have a surface roughness of 0.2㎛ to produce a phosphor plate. The method of measuring luminous efficiency is to measure the radiant flux of the blue LED, which is the light source, in the absence of a glass ceramic phosphor plate, measure the luminous flux by installing a glass ceramic phosphor plate, and then measure the luminous flux of the previously measured blue LED. The luminous efficiency was obtained by dividing by the tube radiation flux value.

[Table 3] (Phosphor plate light efficiency, composition of Example 3)

[Comparative Examples 4 to 6]

The same procedures as Examples 4 to 6 were performed using the glass composition of Comparative Example 3. The results are listed in Table 4.

[Table 4] (Phosphor plate light efficiency, composition of Comparative Example 3))

As a result, as the refractive index increased, the light efficiency tended to increase, but when the refractive index was low, this effect could not be obtained.

When using the glass composition of the present invention, it can be seen that the refractive index and transmittance are high and the thermal characteristics are excellent, and the phosphor plate manufactured using the glass composition of the present invention results in a significant increase in luminous efficiency.

As described above, the present invention has been described in terms of limited examples, but these are provided to facilitate a more general understanding of the present invention, and the present invention is not limited to the above examples, and those with general knowledge in the field to which the present invention pertains. As it grows, various modifications and variations can be made from this substrate.

The above description is merely an illustrative explanation of the technical idea of the present embodiment, and those skilled in the art will be able to make various modifications and variations without departing from the essential characteristics of the present embodiment. Accordingly, the present embodiments are not intended to limit the technical idea of the present embodiment, but rather to explain it, and the scope of the technical idea of the present embodiment is not limited by these examples. The scope of protection of this embodiment should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of rights of this embodiment.

Claims (1)

16 to 22 parts by weight of silicon oxide (SiO ₂ ), 24 to 28 parts by weight of boron oxide (B ₂ O ₃ ), 8 to 12 parts by weight of zinc oxide (ZnO), and 8 to 12 parts by weight of aluminum oxide (Al ₂ O ₃ ) an oxide mixture containing 2 to 6 parts by weight;
Alkaline oxide containing 5 to 7 parts by weight of potassium oxide (K ₂ O), 7 to 8 parts by weight of sodium oxide (Na ₂ O), and 8 to 9 parts by weight of lithium oxide (Li ₂ O); and
Rare earth elements containing a total of 12 to 17 parts by weight of lanthanum oxide (La ₂ O ₃ ), niobium pentoxide (Nb ₂ O ₅ ), neodymium oxide (Nd ₂ O ₃ ), and europium oxide (Eu ₂ O ₃ ). metal oxide
A glass frit composition for a phosphor plate comprising: