KR102340007B1 - Wave-conversion part for light lamp apparatus and light lamp apparatus including the same - Google Patents

Abstract

An embodiment of the present invention provides a ceramic phosphor plate in which at least one ceramic phosphor is dispersed in an oxide mixture matrix including silicon oxide-boron oxide-zinc oxide (SiO ₂ -B ₂ O _{3 -ZnO);} and a wavelength converter for a lighting device in which a light diffusing material including at least one kind of visible light non-absorbing ceramic particles is applied on one surface of the ceramic phosphor plate.

Description

Wavelength converter for lighting device and lighting device including same {WAVE-CONVERSION PART FOR LIGHT LAMP APPARATUS AND LIGHT LAMP APPARATUS INCLUDING THE SAME}

An embodiment of the present invention relates to a lighting device and a wavelength conversion unit constituting the same.

White LEDs have been attracting attention as high-efficiency and high-reliability white light sources, and some have already been used as small-scale light sources with small power. As the luminous efficiency increases, the LED is expanding its scope as a variety of lighting sources. However, the LED is a point light source, and the direct light is strong, and since the emitted light is not of a diffuse type, the beam angle is narrow, and the part that does not receive the light looks dark, which forms a "light spot". In LED packaging and lighting, when a similar color temperature is realized not only on the front side of the light emitting part but also on the side, when applied to a vehicle headlamp, the so-called "light stain" does not occur.

As a method for widening the orientation angle, methods such as attaching a lens to an encapsulant, patterning the surface of the encapsulant, or dispersing particles in the encapsulant are used. However, when ceramic particles are mixed with an encapsulant made of a resin, the particles are not dispersed or precipitated, which is also a factor of lowering the light transmittance of the encapsulant. In addition, when the surface of the encapsulant is patterned, there is a problem in that the process and cost are additionally generated due to the additional patterning process, and the phosphor plate is damaged or the strength is lowered.

The embodiment of the present invention is designed to solve the problems of the prior art as described above, and at least one kind of oxide mixture matrix including _{silicon oxide-boron oxide-zinc oxide (SiO 2} -B ₂ O _{3 -ZnO)} a ceramic phosphor plate in which a ceramic phosphor is dispersed; and a wavelength converter for a lighting device in which a light diffusing material including at least one kind of visible light non-absorbing ceramic particles is applied on one surface of the ceramic phosphor plate, and a lighting device including the same.

In order to achieve the above technical problem, a ceramic phosphor plate in which at least one ceramic phosphor is dispersed in an oxide mixture matrix including silicon oxide-boron oxide-zinc oxide (SiO ₂ -B ₂ O _{3 -ZnO);} and a wavelength converter for a lighting device in which a light diffusing material including at least one kind of visible light non-absorbing ceramic particles is applied on one surface of the ceramic phosphor plate.

In addition, as another aspect of the present embodiment, there is provided a lighting device including the above-described wavelength conversion unit.

According to an embodiment, there is provided a ceramic phosphor plate comprising: a ceramic phosphor plate in which at least one ceramic phosphor is dispersed in an oxide mixture matrix including silicon oxide-boron oxide-zinc oxide (SiO ₂ -B ₂ O _{3 -ZnO);} and a wavelength conversion unit for a lighting device in which a light diffusing material including at least one kind of visible light non-absorbing ceramic particles is applied on one surface of the ceramic phosphor plate, and loss of transmittance and visible light region can be minimized, so that light conversion efficiency is small, light extraction can be improved by suppressing the wave guide phenomenon inside the phosphor plate, and has the effect of improving the beam angle and light uniformity.

1 is a cross-sectional view schematically showing a wavelength converter for a lighting device according to the present embodiment.
2 is a graph showing the evaluation of the directivity angle of the present Example and Comparative Example.
3 is a graph showing in-plane chromaticity deviations of the present Example and Comparative Example.
4 shows the results of comparing the optical properties of the present Example and Comparative Example.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment in which a person of ordinary skill in the art to which the present invention pertains can easily practice the present invention will be described in detail. However, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are only a preferred embodiment of the present invention, and there may be various equivalents and modifications that can be substituted for them at the time of the present application. . In addition, when it is determined that a detailed description of a related well-known function or configuration may unnecessarily obscure the gist of the present invention in describing the operating principle of the preferred embodiment of the present invention in detail, the detailed description thereof will be omitted. The terms described below are terms defined in consideration of functions in the present invention, and the meaning of each term should be interpreted based on the content throughout this specification. The same reference numerals are used throughout the drawings to refer to parts having similar functions and functions.

1 is a cross-sectional view schematically showing a wavelength conversion unit 100 for a lighting device according to the present embodiment.

Referring to FIG. 1 , the wavelength converter 100 for a lighting device according to the present embodiment includes at least one kind of visible light non-absorbing ceramic particles ( The light diffusing material 120 including 122 is applied.

In the present embodiment, in the ceramic phosphor plate 110 , at least one kind of ceramic phosphor is dispersed in an oxide mixture matrix including _{silicon oxide-boron oxide-zinc oxide (SiO 2} -B ₂ O _{3 -ZnO).} The oxide mixture is the main component of the glass-forming composition, wherein the silicon oxide. The three components of the boron oxide and the zinc oxide (SiO ₂ , B ₂ O ₃ , ZnO) form the basic framework of the glass. Additives such as aluminum oxide, bismuth oxide, and alkali metal oxide may be included according to required optical properties and physical/chemical properties. The oxide mixture may be included in 65 wt% to 80 wt% of the components of the ceramic phosphor plate 110 . In this case, the silicon oxide may be included in an amount of 20 wt% to 30 wt% based on the total glass-forming composition. Since the silicon oxide does not significantly affect the properties of the entire glass in the glass-forming composition, it may be appropriately adjusted according to the content of other components.

The ceramic phosphor plate 110 according to the present embodiment uses, as a matrix, a glass frit having a center average particle diameter of 1 μm to 10 μm obtained by vitrifying the glass-forming composition for a ceramic phosphor plate described above, and at least 1 species of phosphors.

The glass frit is mixed with the glass-forming composition including components such as the oxide mixture by a ball mill for 40 to 50 hours, and then put into a melting furnace. The melting temperature may be adjusted according to the composition of the glass-forming composition to be melted. At this time, the melting temperature may be 1300 ℃ to 1600 ℃, it is possible to manufacture the glass according to a conventional glass manufacturing process. The temperature at which the raw material contained in the glass-forming composition can be uniformly dissolved is selected and melted. At this time, if the temperature is increased to exceed 1600° C., there is a risk that the volatile component may increase. The melt is poured into twin rolls to perform quenching, thereby preparing a glass cullet. The glass cullet is pulverized to prepare a glass frit.

The glass frit may have an average particle diameter of 1 μm to 10 μm, preferably 2 μm to 7 μm. When the particle size of the glass frit is reduced, the internal porosity after sintering is reduced, which is advantageous for improving optical properties. When the particle diameter of the glass frit exceeds 10 μm, there is a fear that a plurality of pores may be formed when mixed with a phosphor and sintered later. On the other hand, when the particle diameter of the organic frit is less than 1 μm, when mixed with the phosphor, the organic frit may not be sufficiently dispersed and thus the phosphor may not be sufficiently passivated. In addition, as the milling time increases, the degree of contamination also increases, making it difficult to maintain whiteness after sintering.

The ceramic phosphor may be one of yellow, green, or red phosphors depending on the required optical characteristics, lighting color, and application field, and may be one or more ceramic phosphors that excite light of different wavelengths as needed. have. The ceramic phosphor is a yttrium-aluminum-garnet (YAG)-based, ruthenium-aluminum-garnet (LuAG)-based, nitride-based, sulfide-based or silicate-based phosphor. can be used

The ceramic phosphor is mixed in an amount of 10 wt% to 30 wt% with respect to the glass frit. At this time, the amount of phosphor mixture may be slightly changed according to transmittance and color difference after sintering. In addition, the content of the phosphor is also changed according to the change in the thickness. When the thickness is increased, the phosphor can be added by reducing the amount.

The mixture of the glass frit and the ceramic phosphor is put into a SUS (Stainless Use Steel, SUS) mold to have a plate or disk shape, and put in a kiln to perform firing. Sintering is performed in an air atmosphere in a common box furnace. The sintering condition may be performed at a temperature of 600° C. to 700° C. for 20 minutes to 1 hour. In this case, the temperature and time for sintering may be adjusted according to the glass transition temperature (Tg) of the ceramic phosphor and the glass frit.

On the ceramic phosphor plate 110 of the wavelength converter 100 for a lighting device according to the present embodiment, a light diffusing material 120 including visible light non-absorbing ceramic particles 122 is provided to improve a beam angle. is applied In the embodiment of the present invention, the visible light non-absorbing ceramic particles 122 should have an optical bandgap of 3.3 eV or more. In addition, the visible light non-absorbing ceramic particles 122 are particles that do not absorb light in the visible light band, that is, in the wavelength range of 380 nm or more. Accordingly, since light in the visible light band is reflected or transmitted without absorbing the light, it may be a white particle. As an example of the visible light non-absorbing ceramic particles 122 , _{white particles such as zirconium oxide (ZrO x} ), titanium oxide (TiO _x ), zinc oxide (ZnO), or magnesium oxide (MgO) may be used.

The average particle diameter (D50) of the visible light non-absorbing ceramic particles 122 may be 0.5 μm to 1.5 μm. When the average particle diameter (D50) of the visible light non-absorbing ceramic particles 122 is less than 0.1 μm, the visible light scattering rate may be lowered, and there is a risk of aggregation without being dispersed from each other. On the other hand, in the case of exceeding 1.5 μm, the particle size is too large, and there is a problem in that the chromaticity deviation is lowered or the appearance looks like a non-uniform stain.

The visible light non-absorbing ceramic particles 122 are coated on the heat-resistant adhesive resin 124 to be coated on the ceramic phosphor plate 110 . In this case, the heat-resistant adhesive resin 124 may be a silicone-based resin, and is not particularly limited as long as it is a type that does not deteriorate even at 250° C. or higher. However, in this embodiment, when the light diffusing material 120 is applied on the ceramic phosphor plate 110, the visible light non-absorbing ceramic particles 122 must be applied in one layer (as shown in FIG. 1), The thickness of the heat-resistant adhesive resin 124 is preferably 3 μm or more and 15 μm or less. According to Example 2, when the thickness is 3 μm or less, it may be difficult to properly implement the desired effect, and when the thickness is 15 μm or more, it may be difficult to implement in a single process in the coating process. However, as shown in Example 2 to be described later, in the thickness within this range, as the thickness increases, the characteristics of chromaticity deviation and orientation angle are improved.

1 wt% or less of the visible light non-absorbing ceramic particles 122 may be applied based on the weight of the ceramic phosphor plate 110 . As described above, since the visible light non-absorbing ceramic particles 122 are preferably coated on the ceramic phosphor plate 110 in one layer, the visible light non-absorbing ceramic particles 122 exceed 1% based on the weight of the ceramic phosphor plate 110 . In this case, there is a fear that the thickness of the applied light diffusing material 120 may be different depending on the location, and there is a risk that the directivity angle may not be improved.

A lighting device according to another aspect of the present embodiment is one surface of a ceramic phosphor plate in which at least one ceramic phosphor is dispersed in an oxide mixture matrix including _{silicon oxide-boron oxide-zinc oxide (SiO 2} -B ₂ O _{3 -ZnO)} a wavelength converter on which a light diffusing material including at least one kind of visible light non-absorbing ceramic particles is applied thereon; and a light source element.

The wavelength converter can be divided into two types according to the positional relationship with the light source element. A remote type in which the wavelength converter and the light source element are spaced apart from each other by a predetermined distance and a direct attach type in which the wavelength converter is bonded to the light source element.

The spaced type is mainly applied to lighting, and as indoor lighting, it is used in a Down Light Module (DLM) or a Spot Light Module (SLM). In addition, for outdoor use, it is applicable to a street light module such as a street light. The all-in-one type is applied to high-power LED packaging and is mainly applicable to vehicle headlamps and daytime running lamps (DRLs) as exterior lighting of the vehicle, and can also be used as a light source for an LED beam projector.

The separation type prevents the wavelength conversion unit from being deformed or characteristics from being reduced due to heat from the light source element. On the other hand, in the case of the integrated type, since the thickness of the wavelength converter can be set to be thin, the size of the lighting device can be greatly reduced.

In the case of the spaced apart type, the lighting device includes a housing having a shape that becomes wider from the bottom to the top with the light source element mounted on the packaging as the center. As the light source device, a solid light emitting device may be applied as an example. As the solid-state light emitting device, any one selected from among LED, OLED, LD (laser diode), Laser, and VCSEL may be applied. The wavelength converter is provided at the upper end of the housing, and is disposed to be spaced apart from the light source 120 . As described above, in the wavelength converter according to the present embodiment, a light diffusing material is coated on a matrix made of glass frit and a ceramic phosphor plate including a ceramic phosphor dispersed in the matrix. At this time, the thickness of the wavelength conversion part is 500㎛ to 1000㎛. The inside of the housing may be filled with a material having a refractive index equal to or higher than that of the wavelength conversion unit.

The distance from the light source element may be 10 mm to 20 mm. The separation distance may be preferably 12 mm to 18 mm. When the separation distance exceeds 20 mm, there is a fear that light extraction is not sufficiently performed. On the other hand, when the separation distance is less than 10 mm, there is a risk that the ceramic phosphor may be thermally deformed by heat generated from the light source element.

In the case of the bonding type, the light source element mounted on the packaging is the same as the above-described integrated type, but the wavelength converter is directly mounted on the light source element. In the case of the junction type, since the wavelength converter is directly mounted on the light source element, it may be directly affected by the heat of the light source element. However, the thickness of the wavelength conversion unit is 80㎛ to 200㎛, it is possible to reduce the thickness than the integrated wavelength conversion unit. In addition, it is possible to exclude the housing used in the integral type, and to reduce the space corresponding to the separation distance between the light source and the wavelength converter, it is possible to implement a compact size lighting device.

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are provided to help the understanding of the present invention, and the scope of the present invention is not limited to these examples in any sense.

[ Example ]

Example One

(A-SiAlON phosphor having an average particle size (D50) of 5-8 μm and a main emission peak of 540 nm and a-SiAlON of 580 nm or more) Zirconium having an average particle diameter (D50) of 1 μm in a silicone resin (Si) on a phosphor plate The oxide (ZrO ₂ ) was dispersed and applied by spray coating, followed by drying. At this time, the amount of zirconium oxide was added to be 1% based on the weight of the phosphor plate.

[ comparative example ]

comparative example One

The same phosphor plate as in Example 1 was used, but zirconium oxide was not applied.

comparative example 2

The same phosphor plate as in Example 1 was used, but a lithography process was performed to form a pattern (concave-convex lens array type) on the surface.

[evaluation]

One. direction angle improvement evaluation

Deviations were confirmed by measuring Cx and Cy values of 14000 points or more in a high-power chip of 980 μm×980 μm, and the results are shown in Table 1 and FIG. 2 .

LED driving condition: IF = 350mA, Tb = 25℃

[Table 1]

Referring to Table 1 and Figure 2, it can be _{seen that the method of applying Example 1 of the present invention, in which zirconium oxide (ZrO 2} ) is dispersed and applied by spray coating on the surface of the phosphor plate, is the most excellent in terms of the measurement result of the orientation angle. have. In addition, Comparative Examples 1 and 2 are disadvantageous in terms of directivity angle characteristics, as well as an additional process for implementing a pattern using a process such as photolithography, which is disadvantageous in terms of an increase in cost.

2. Measurement of in-plane chromaticity deviation

In-plane chromaticity deviation was measured with the Source Imaging Goniometer System, and the results are shown in Table 2 and FIG. 3 .

Referring to the results of Table 2 and Figure 3 below, even in this case, the method in which Example 1 of the present invention was applied by spray coating by dispersing _{zirconium oxide (ZrO 2 ) on the surface of the phosphor plate was the result of in-plane chromaticity deviation} It can be confirmed that it is superior to that of other Comparative Examples 1 and 2.

[Table 2]

3. Changes in optical properties due to light diffusing material coating

In Example 1 (using two samples), the optical properties before and after coating the zirconium oxide particles were measured, and the difference is shown in Table 3.

[Table 3]

_{Zirconium oxide (ZrO 2} ) Dispersing zirconium oxide (ZrO 2 ) on the surface of the phosphor plate and applying Example 1 of the present invention applied by spray coating, and zirconium oxide (ZrO ₂ ) When comparing the characteristics of not coating, this Example 1 It can be seen that the luminous flux increases in , and the color coordinates and orientation angle are improved.

Example 2

(A-SiAlON phosphor having an average particle size (D50) of 5-8 μm and a main emission peak of 540 nm and a-SiAlON of 580 nm or more) Zirconium having an average particle diameter (D50) of 1 μm in a silicone resin (Si) on a phosphor plate The oxide (ZrO ₂ ) was dispersed and applied by spray coating, followed by drying. At this time, the amount of zirconium oxide was added to be 1% based on the weight of the phosphor plate. In particular, in Example 2, the chromaticity deviation and the change in the orientation angle were measured by changing the thickness of the coating. As a comparison object, a non-coated phosphor plate was used as a comparison group (Ref).

The results of comparing the optical properties of Example 2 and the comparative group are shown in Table 4 and FIG. 4 .

[Table 4]

As a result of the above measurement, referring to FIGS. 4 and 4 , it can be clearly seen that the chromaticity deviation and the orientation angle are improved as compared to the comparative group (Ref) that is not coated with zirconium oxide. Furthermore, in Example 2, it can be seen that as the coating thickness of zirconium oxide increases, the improvement effect of chromaticity deviation and orientation angle increases. (However, coating once: ZrO2-1, coating twice: ZrO2-2, coating 3 times: ZrO2-3, no coating: Ref)

In addition, as can be seen in FIG. 4 (ZnO coating once: ZnO-1) even when the material to be coated under the same conditions in the above experiment was applied as ZnO (zinc oxide), almost the same results as the zirconium oxide of Example 2 were obtained. You can see what you can get. Table 5 below shows the results of coating zinc oxide under the same conditions as in Example 2.

[Table 5]

Also, in the case of zinc oxide, the effect of improving the chromaticity deviation and the orientation angle increases as the coating thickness increases.

The above description is merely illustrative of the technical spirit of the present invention, and various modifications and variations will be possible without departing from the essential characteristics of the present invention by those skilled in the art to which the present invention pertains. Therefore, the embodiments disclosed in the present invention are intended to explain, not to limit the technical spirit of the present invention, the protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent range It should be construed as being included in the scope of the present invention.

100: wavelength conversion unit for lighting devices
110: ceramic phosphor plate
120: light diffusing material
122: visible light non-absorbing ceramic particles
124: adhesive resin

Claims (12)

A ceramic phosphor plate comprising at least one ceramic phosphor dispersed in an oxide mixture matrix comprising silicon oxide-boron oxide-zinc oxide (SiO ₂ -B ₂ O _{3 -ZnO),}
A light diffusing material including at least one kind of visible light non-absorbing ceramic particles is applied on one surface of the ceramic phosphor plate,
The visible light non-absorbing ceramic particles reflect or transmit without absorbing a wavelength region of 380 nm or more,
In order to prevent a decrease in visible light scattering rate and a decrease in chromaticity deviation, the visible light non-absorbing ceramic particles have an average particle diameter (D50) of 0.5 μm to 1.5 μm,
A wavelength converter for a lighting device in which 1 wt% or less of the visible light non-absorbing ceramic particles are applied based on the weight of the ceramic phosphor plate in order to uniform the thickness of the light diffusing material to prevent a decrease in the orientation angle.
The method according to claim 1,
The ceramic phosphor,
Yttrium-aluminium-garnet (Yttrium Aluminum Garnet; YAG)-based, ruthenium-aluminium-garnet (Lutetium aluminum garnet; LuAG)-based, nitride-based, sulfide-based, silicate-based and mixtures thereof At least one wavelength converter for a lighting device selected from the group consisting of.
The method according to claim 1,
The visible light non-absorbing ceramic particles,
A wavelength converter for lighting devices with an optical bandgap of 3.3eV or more.
4. The method according to claim 1 or 3,
The visible light non-absorbing ceramic particles,
Zirconium oxide (ZrO _x ), titanium oxide (TiO _x ), zinc oxide (ZnO), or at least one wavelength conversion unit for a lighting device selected from the group consisting of magnesium oxide (MgO).
delete The method according to claim 1,
The light diffusing material,
A wavelength converter for a lighting device in which the visible light non-absorbing ceramic particles are dispersed in a heat-resistant adhesive resin and applied on the ceramic phosphor plate.
7. The method of claim 6,
The light diffusing material,
A wavelength conversion unit for a lighting device in which the thickness of the heat-resistant adhesive resin applied on the ceramic phosphor plate is 1 μm or less.
delete At least one visible light non-absorbing ceramic on one surface of a ceramic phosphor plate in which at least one ceramic phosphor is dispersed in an oxide mixture matrix comprising silicon oxide-boron oxide-zinc oxide (SiO ₂ -B ₂ O _{3 -ZnO)} a wavelength conversion unit to which a light diffusing material containing particles is applied; and
light source element;
includes,
The visible light non-absorbing ceramic particles reflect or transmit without absorbing a wavelength region of 380 nm or more,
In order to prevent a decrease in visible light scattering rate and a decrease in chromaticity deviation, the visible light non-absorbing ceramic particles have an average particle diameter (D50) of 0.5 μm to 1.5 μm,
A lighting device in which 1 wt% or less of the visible light non-absorbing ceramic particles are applied based on the weight of the ceramic phosphor plate in order to uniform the thickness of the light diffusing material to prevent a decrease in the orientation angle. delete delete delete

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