KR100647823B1 - Warm white light emitting device for lighting applications - Google Patents

Abstract

The present invention relates to a white light emitting device for illumination, and more particularly, to a white light emitting device including a blue light emitting device and a phosphor coating layer formed on the blue light emitting device and including a transparent resin, a borate-based yellow phosphor, and a red phosphor. Provide the device. The white light emitting device of the present invention is formed on a blue semiconductor light emitting device and a blue light emitting device, the yellow phosphor absorbs a part of the blue light illuminated from the blue light emitting device to emit light in the yellow wavelength region and light in the red wavelength region, respectively And a red phosphor; and may provide warm white light by mixing blue, yellow, and red light.

White light emitting device, terbium borate yellow phosphor, red phosphor

Description

White light emitting device for lighting {WARM WHITE LIGHT EMITTING DEVICE FOR LIGHTING APPLICATIONS}

1 is a schematic configuration diagram and a partially enlarged cross-sectional view of a lead type lighting white light emitting device employing a borate-based yellow phosphor and a red phosphor according to an embodiment of the present invention.

2 is a schematic configuration diagram of a surface-mounted lighting white light emitting device of a reflector injection structure type employing a borate-based yellow phosphor and a red phosphor according to an embodiment of the present invention.

3 is a graph showing the absorption spectrum and the emission spectrum of the borate-based yellow phosphor according to an embodiment of the present invention,

Figure 4 is a graph showing the absorption spectrum and emission spectrum of the strontium sulfide red phosphor according to an embodiment of the present invention,

5 is a graph showing light emission spectra of a white light emitting diode in combination with a borate-based yellow phosphor, a red phosphor, and a blue LED according to an embodiment of the present invention;

6 is a color coordinate showing a color gamut that can be realized by a light emitting diode in combination with a borate-based yellow phosphor, a red phosphor and a blue LED according to an embodiment of the present invention.

FIG. 7 illustrates a color coordinate region A of a white light emitting device for lighting, which is implemented by combining a terbium borate-based yellow phosphor, a red phosphor, and a blue light emitting device according to an embodiment of the present invention. Color coordinate area shown in comparison with).

Explanation of symbols on the main parts of the drawings

3, 10: LED chip 4, 11: anode lead

5, 12: cathode lead 6, 13: phosphor coating layer

8: phosphor particle 9, 17: recessed portion

16: casing 15: molding layer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor light emitting device, and more particularly, by employing a yellow light emitting phosphor and a red light emitting phosphor to absorb a portion of light emitted by a semiconductor light emitting element, thereby emitting light having a wavelength different from that of absorbed light. The present invention relates to a light emitting device that realizes warm white light by a combination.

A semiconductor light emitting diode (LED) is a PN-bonded compound semiconductor, which is a type of optoelectronic device that emits energy corresponding to the bandgap of a semiconductor in the form of light by combining electrons and holes when a voltage is applied. device).

With the development of high-brightness blue LEDs by GaN-based nitride semiconductor light emitting materials, and the full colorization of LEDs is realized, the use of LEDs is expanding not only for display devices of display devices but also for lighting. Lighting LEDs have about 10-15% lower power consumption, more than 100,000 hours of semi-permanent lifespan, and environmentally friendly characteristics compared to conventional luminaires such as fluorescent and incandescent lamps, which can dramatically improve energy consumption efficiency. .

In order for a semiconductor light emitting device to be applied for lighting, white light must be obtained using an LED. Three methods are known for implementing a lighting white light emitting device. The first method combines three LEDs of red, green, and blue, which are three primary colors of light, to realize white color, and uses InGaN and AlInGaP phosphors as light emitting materials. In this method, it is not easy to make white LEDs by configuring RGB three-color LEDs on a single chip, and the materials and methods of making each LED are different, and the driving voltage of each LED is different to control the current strength. Is not easy. The second method is to realize white by exciting three primary phosphors by using an ultraviolet LED as a light source. InGaN / R, G, B phosphors are used as light emitting materials. This method can be used under high current and can improve color. However, there is a problem in that development of a material for red color implementation is not satisfactory and light attenuated by the emission wavelength of each phosphor when light emitted from a short wavelength ultraviolet LED is absorbed and emitted by the phosphor.

The third method is to implement white by exciting a yellow phosphor by using a blue LED as a light source. InGaN / YAG: Ce phosphor is generally used as a light emitting material. There is a problem that the color rendering is not good by using a yellow phosphor, but has been applied as a superior to the above method in terms of price, light characteristics and ease of application.

The efficiency of the luminaire using the phosphor increases as the difference between the wavelength of the excitation radiation and the wavelength of the emitted light is small. Therefore, the light emission characteristic of the phosphor serves as a very important factor in determining the color and luminance of the semiconductor light emitting device. Phosphors are generally composed of a matrix of crystalline inorganic compounds and an activator that converts the matrix into an effective fluorescent substance. It is a material that emits light mainly in the visible region while returning to the state. The color of the emitted light can be controlled by an appropriate combination of the inorganic compound parent and the active agent.

Examples of those known as conventional white light emitting devices for lighting include the following.

Nichia's U.S. Patent Nos. 5,998,925 and 6,069,440 disclose white light emitting devices using nitride semiconductors, including In _i Ga _j Al _k N (0≤i, 0≤j, 0≤k, i + j + k = 1 And a YAG (Yttrium, Aluminum, Garnet) -based garnet fluorescent material that absorbs a part of the light emitted by the blue light emitting device and emits light having a wavelength different from that of the absorbed light. A light emitting device including a yellow phosphor containing a metal is disclosed, wherein the YAG-based phosphor includes Y ₃ (Al _{1 -s} Ga _s ) ₅ O ₁₂ : Ce as a first phosphor and Re ₃ Al _{5 as} a second phosphor. A mixture of O ₁₂ : Ce (0 ≦ s ≦ 1, Re is at least one of Y, Ga and La) may be used.

Osram's U.S. Patent 6,504,179 discloses the BYG approach (combination of blue, yellow and green), unlike the conventional RGB approach (using a combination of red, green and blue) and BY approach (using a combination of blue and yellow). Disclosed is a white lighting device employing a method). This white illuminator includes an LED which emits a first light in the region of 300 nm to 470 nm as a light source, which is converted into long wavelength light by a phosphor exposed to the first light. Eu-resilient calcium magnesium chlorosilicate-based green phosphors and Ce-resilient rare earth garnet-based yellow phosphors are used as materials to assist such conversion. Ce-reactive rare earth garnet-based yellow phosphors include Re ₃ (Al, Ga) ₅ O ₁₂ : Ce (Re is Y and / or Tb, in which 20% or more of the emitted light emits light corresponding to a visible region of 620 nm or more. Phosphor represented by) is used.

In addition, U.S. Patent 6,596,195 to General Electric, Inc. can be excited by light in the near-ultraviolet to blue wavelength range (about 315 nm to about 480 nm) and in the green to yellow wavelength range (about 490 nm to about 770). A phosphor emitting visible light showing a peak of emission in a broad range of nm) and a white light source employing the same have a garnet structure and have a general formula (Tb _1-xy A _x Re). _y ) ₃ D _z O ₁₂ (A is selected from Y, La, Gd and Sm, and Re is selected from Ce, Pr, Nd, Sm, Eu, Gd, Dy, Ho, Er, Tm, Yb and Lu) D is at least one selected from Al, Ga, and In, A and Re are not the same, x is 0 to 0.5, y is 0.0005 to 0.2, and z is 4 to 5). Is displayed.

As described above, white light emitting diodes are mostly manufactured by combining YAG: Ce phosphors with blue LEDs, and are being spotlighted as backlights for LCDs such as lighting, notebooks, and mobile phones. A white LED using a blue LED is mainly capable of producing a white light emitting device for lighting by mixing blue and yellow by exciting and emitting a YAG: Ce yellow phosphor located in an upper layer by a blue light source in the wavelength range of 450 to 470 nm. However, the white light of the white LED using the blue LED in the 450 ~ 470nm wavelength is a cold sound that feels psychologically cold, so there is a disadvantage that it is not suitable for indoor lighting. Therefore, there is a need for a light emitting device for expressing such cool white light as warm light.

The present invention is to solve the above-mentioned problems of the prior art, an object of the present invention is to absorb the blue light emitted from the blue light emitting device and a part of the emitted blue light is terbium borate-based yellow phosphor and red light emission that can emit yellow light By employing a phosphor coating layer containing possible red phosphors, it is to provide a warm white light emitting device (Warm White LED) by a mixture of these blue, yellow and red.

In one aspect of the invention, a white semiconductor light emitting device comprising a blue semiconductor light emitting element, and a phosphor coating layer formed on the light emitting element,

The phosphor coating layer may include a transparent resin, a terbium borate-based yellow light emitting phosphor represented by the following Chemical Formula 1, which absorbs light emitted by the semiconductor light emitting device and emits light having a wavelength different from that of the light absorbed by the semiconductor light emitting device, and a red light emission. Lighting white light emitting device comprising a phosphor:

(Formula 1)

(Tb _{1 -xy- z} RE _x A _y ) ₃ D _a B _b O ₁₂ : Ce _z

In the above formula, RE is at least one rare earth element selected from the group consisting of Y, Lu, Sc, La, Gd, Sm, Pr, Nd, Eu, Dy, Ho, Er, Tm and Yb, and A is Li, Na, Is a metal element of at least one typical element selected from the group consisting of K, Rb, Cs and Fr, D is an amphoteric element of at least one typical element selected from the group consisting of Al, In and Ga, 0 ≦ x It is <0.5, 0 <y <0.5, 0 <z <0.5, 0 <a <5, and 0 <b <5. Preferably it is 0 <x + y + z <1, More preferably, it is 0 <x + y + z <0.5. In the above formula, preferably, 4 ≦ a + b ≦ 7, and more preferably 4 ≦ a + b ≦ 6. In addition, it is preferable that 0.05 <x <0.3, 0.05 <y <0.25, and 0.005 <z <0.015.

In still another aspect of the present invention, there is provided a white light emitting device for lead type and surface mount type lighting having various structures.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a white light emitting device for lighting, comprising a blue semiconductor light emitting device, a yellow light emitting phosphor, a red light emitting phosphor, and a transparent resin, and including a phosphor coating layer formed on the light emitting device.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a white light emitting device, and more particularly, employing a yellow light emitting phosphor and a red light emitting phosphor to absorb a portion of light emitted by a semiconductor light emitting element, thereby emitting light having a wavelength different from that of absorbed light. The present invention relates to a light emitting device that realizes warm white light by a combination. Generally, white light is defined by CIE in the range of 2,500K (Reddish White) to 20,000K (Bluish White) in terms of color temperature (CCT), and the one close to 2,500K is called warm white. do. In the present invention, warm white light is intended to mean white light in the 2,500K to 6,000K range at the color temperature. The white light implemented in the white light emitting device of the present invention is preferably white light in the color temperature range of 2,500K to 6,000K, more preferably in the color temperature of 2,500K to 4,000K. In the case of the white light emitting device using the yellow phosphor alone, since the cool white light is implemented by itself, it is difficult to realize the warm white by itself. In the present invention, the warm white light is implemented by combining with the red light emitter.

The phosphor coating layer may include a transparent resin, a terbium borate-based yellow light emitting phosphor represented by the following Chemical Formula 1, which absorbs light emitted by the semiconductor light emitting device and emits light having a wavelength different from that of the light absorbed by the semiconductor light emitting device, and a red light emission. It should contain a phosphor.

The yellow phosphor applied in the present invention exhibits an absorption peak in the range of about 420 nm to 480 nm, and an emission peak in the range of about 500 nm to 650 nm.

The yellow phosphor according to the present invention is a terbium borate-based phosphor represented by the following formula (1).

(Formula 1)

(Tb _1-xyz RE _x A _y ) ₃ D _a B _b O ₁₂ : Ce _z

In the above formula, RE is at least one rare earth element selected from the group consisting of Y, Lu, Sc, La, Gd, Sm, Pr, Nd, Eu, Dy, Ho, Er, Tm and Yb, and A is Li, Na, Is a metal element of at least one typical element selected from the group consisting of K, Rb, Cs and Fr, D is an amphoteric element of at least one typical element selected from the group consisting of Al, In and Ga, 0 ≦ x It is <0.5, 0 <y <0.5, 0 <z <0.5, 0 <a <5, and 0 <b <5.

Preferably it is 0 <x + y + z <1, More preferably, it is 0 <x + y + z <0.5. In the above formula, preferably, 4 ≦ a + b ≦ 7, and more preferably 4 ≦ a + b ≦ 6. In addition, it is preferable that 0.05 <x <0.3, 0.05 <y <0.25, and 0.005 <z <0.015.

In the above general formula, when x and z are in the numerical range, preferable luminous efficiency can be obtained. In addition, when y is in the above numerical range, Ce may exhibit an appropriate function as an activator, and when it is out of the upper limit, luminance may decrease due to a quenching effect. The yellow phosphor exhibits an absorption peak in the range of about 420 nm to 480 nm and an emission peak at about 500 nm to 650 nm.

The terbium borate-based yellow phosphor may be produced by a solid phase method, a liquid phase method, or a vapor phase method which is commonly used as a phosphor manufacturing method. In the method for producing the terbium borate-based phosphor powder of the present invention, the structure of the phosphor obtained may vary depending on the type of the metal compound constituting the phosphor matrix and the metal compound doped with the matrix. Specific examples of preparing the terbium borate-based yellow phosphor may include a precursor solution including a compound containing at least one element selected from the group consisting of aluminum, indium, and gallium, a terbium-containing compound, a cerium-containing compound, and boronic acid. Doing; Spraying the precursor solution to form droplets; And drying and thermally decomposing the droplets at 200 to 1500 ° C., and then performing post-heat treatment at 800 to 1800 ° C. FIG. Details of terbium borate-based yellow phosphors and methods for their preparation which can be used in the present invention are described in detail in WO 2004/099342.

Red phosphors usable in the present invention are provided with red phosphors represented by the following Chemical Formulas 2 to 4 (SrS: Eu, CaS: Eu, Ca ₂ Si ₅ N ₈ : Eu):

(Formula 2)

(Sr _1-X ) S: Eu _X

In Chemical Formula 2,

Study lubricant Eu is preferably set at a ratio within the range of 0.001≤X≤0.1mol,

The red phosphor exhibits an absorption peak in the range of about 420 nm to 540 nm, and an emission peak in the range of about 560 nm to 700 nm.

(Formula 3)

(Ca _1-x S): Eu _X

In Chemical Formula 3,

Study lubricant Eu is preferably set at a ratio within the range of 0.001≤X≤0.1 mol,

The red phosphor exhibits an absorption peak in the range of about 420 nm to 540 nm and an emission peak in the range of about 500 nm to 700 nm.

(Formula 4)

(Ca _1-X ) ₂ Si ₅ N ₅ : Eu

In Chemical Formula 4,

Study lubricant Eu is preferably set at a ratio within the range of 0.001≤X≤0.2 mol,

The red phosphor exhibits an absorption peak in the range of about 300 nm to 500 nm, and an emission peak in the range of about 500 nm to 700 nm.

The luminescent phosphor applicable to the present invention may be prepared by a solid phase method, a liquid phase method, or a vapor phase method commonly used in the art, and among them, spray pyrolysis, which is a kind of vapor phase method, to produce a phosphor having a small particle size to a nano level. It is preferable to use a method. Yellow phosphors with nano-sized particles produced by the spray pyrolysis process showed a significant improvement in the luminescence properties despite the narrow particle size distribution. In the process of ball milling to reduce the defects on the surface of the phosphor may reduce the brightness, while the phosphor powder produced by the spray pyrolysis process is present as one particle, or one particle is a plurality of particles by recrystallization By dividing by This is because luminance reduction does not occur. The phosphor particles produced by the ultrasonic spray pyrolysis process have an average particle diameter of 100 nm to 10 μm.

To realize a warm white color, the yellow light-emitting phosphor may contain 0.01-70 parts by weight, and preferably 10-20 parts by weight, based on 100 parts by weight of the transparent resin in the phosphor coating layer. The red light-emitting phosphor may contain 0.01-60 parts by weight, preferably 25-40 parts by weight based on 100 parts by weight of the yellow light-emitting phosphor.

The white light emitting device includes a transparent resin that is formed on the light emitting device to reduce the optical path difference by refracting and transmitting the light illuminated by the light emitting device. The transparent resin is made of epoxy and / or silicone resin.

In this case, the yellow and red phosphors are irregular to the transparent resin, or yellow phosphors and red phosphors are alternately adjacent to each other and are formed in a matrix array structure. For example, the yellow and red phosphors are sufficiently precipitated and filled in a liquid transparent resin having a predetermined viscosity, and then, the transparent resin is cured so that the mold material solidifies. As such, when the transparent resin is solidified with yellow and red phosphors sufficiently precipitated in the transparent resin, the light generated from the light emitting device is absorbed by the particles forming the yellow and red phosphors, scattered, and the desired color coordinate region. Warm white light control becomes possible.

At this time, the particle size (particle size) of the yellow phosphor and the red phosphor contained in the transparent resin is preferably used to separate the sieve to an appropriate size so that the color mixture of the target color coordinate region can be made according to the mixing ratio. That is, the particle size of the yellow and red phosphors preferably has a particle size in the range of approximately 0.1 to 50 ㎛. Further, the particle shape is preferably formed in a spherical shape, polygonal shape or plate shape.

Since the phosphor mainly emits light on the surface of the powder, the smaller the particle size is, the more the surface area of the particle increases, and thus the emission intensity increases. However, when the particle size becomes smaller than a certain limit, since scattered light may be absorbed and disappeared between the particles, it is necessary to use a phosphor having an optimal particle size for showing the best emission characteristics.

The specific gravity of the fluorescent material is several times that of the liquid resin before curing. In addition, the thermosetting resin is greatly reduced in viscosity during heat curing. Therefore, when the LED chip is covered with a liquid resin containing a fluorescent material and thermally cured, most of the fluorescent material in the resin tends to be concentrated and settled around the LED chip. Since the fluorescent materials that are densely gathered and sedimented in this way overlap with each other and are settled around the LED chip, only the fluorescent material located in the vicinity of the surface of the LED chip can efficiently absorb light from the LED chip. Therefore, most of the fluorescent material does not sufficiently exhibit the function of converting the wavelength, but rather serves to block light converted by the other fluorescent material and to attenuate the light energy. As a result, the lowering of the light emitting output of the light emitting diode can be caused.

Therefore, in the present invention, the fluorescent material having a specific particle size, shape and distribution in order to utilize the surface light emitting properties of the fluorescent material so that as much of the fluorescent material can exhibit the conversion function to maximize the light Are using them.

The form of the yellow phosphor and the red phosphor is not particularly limited, but is formed in a spherical shape, a polygonal shape or a plate shape, and a spherical shape is more preferable. The phosphor also has a particle size in the range of approximately 0.1-50 μm, more preferably 0.1-30 μm. If the particle size of the phosphor is 50 μm or more, the light emitting area of the phosphor is reduced, and thus the amount of the phosphor is used to increase light blocking and attenuation. In the light emitting characteristic can be drastically reduced.

As described above, in mixing the yellow and red phosphors with respect to the transparent resin, uniform mixing is difficult as the particle size distribution of the yellow and red phosphors is small or the mixing ratio is high. In view of this, it is possible to increase the mixing ratio between the transparent resin and the yellow and red phosphors by using a mill or roll equipment to densify the distribution of color coordinates and improve the product yield.

The main peak of the emission spectrum of the semiconductor light emitting device used in the present invention is in the range of 400 nm to 530 nm, the main emission wavelength of the yellow light emitting phosphor and the red light emitting phosphor is longer than the main peak wavelength of the semiconductor light emitting device. Do.

The semiconductor light emitting device includes a substrate and a light emitting layer made of a nitride semiconductor compound formed on the substrate. The substrate is formed of sapphire (Al ₂ O ₃ ) or silicon carbide (SiC), the nitride semiconductor layer comprises a GaN, InGaN, or InGaAlN semiconductor.

The light emitting diode according to the embodiment of the present invention has a high energy band gap in the light emitting layer and combines a semiconductor device such as a gallium nitride-based (InGaN) compound capable of emitting blue light, and a borate-based yellow phosphor and a red phosphor capable of emitting yellow light. As a result, a warm white color can be realized by mixing blue light emitted from the light emitting element with yellow and red light emitted from the phosphor excited by the light emission. In addition, even when the high-energy light in the visible band emitted from the light emitting element is irradiated for a long time, it is shown that the change in the emission color and the decrease in the emission luminance are very small.

In the packaging process, the lighting white light emitting device of the present invention may be manufactured in a surface mount type or a lead type, and materials for such packaging include metal stems, lead frames, ceramics, and printed circuit boards. Packaging is a process made for electrical connection with the outside, protection against mechanical, electrical and environmental factors from the outside, thermal diffusion, increase in luminous efficiency, and optimization of directivity.

1 shows a configuration diagram and a partially enlarged cross-sectional view of a lead-type white light emitting device for illumination. That is, the white light emitting device for lead type lighting has a cup-shaped recess 9 on the lead frame, and includes an LED chip 3 and a phosphor coating layer 6 on the recess 9. (3) has a structure connected to the anode 4 and the cathode 5 by the metal wires (1, 2), it is possible to apply a current to the LED chip (3), the anode (4) And a part of the cathode 5 is enclosed in the exterior member 7 made of a colorless or colored translucent material exposed to the outside. The inner wall of the recess 9 serves as a reflector, and the phosphor coating layer 6 includes phosphor particles 8 and a transparent resin, and the phosphor particles 8 are yellow phosphor and red phosphor of the present invention. It may include particles. The LED chip 3 may be protected by physical force while the LED chip 3 is fixed to the recess 9 so that the LED chip 3 and the anode and cathode wires 1 and 2 are fixed. A part is molded together by the transparent resin.

2 shows a cross-sectional view of a white light emitting device for illumination of a reflector injection structure type as an example of a surface mount type. According to Fig. 2, the casing 16 having the recessed portion 17 formed thereon is provided with metal terminals 11 and 12 serving as anodes and cathodes. The LED chip 10 and the metal terminals 11 and 12 are connected to the N-type electrode and the P-type electrode by metal wires 14, respectively. An LED chip 10 is disposed in the recess 17, and a phosphor coating layer 13 containing transparent resin and phosphor particles is disposed thereon, and the upper surface of the recess 17 is again disposed thereon. Since the transparent molding layer 15 is positioned to form the same surface, metal wires and the like are embedded therein and are not exposed to the outside. The inner wall of the recess 17 acts as a reflecting plate, and the recess 17 may be formed by injection molding or the like. The phosphor coating layer may include a yellow light emitting phosphor and may further include a red light emitting phosphor.

3 shows absorption and emission spectra of a terbium borate yellow light emitting phosphor ((Tb _0.84 Gd _0.1 Ba _0.05 ) Al _4.5 B ₁ O ₁₂ : Ce _0.01 ) according to an embodiment of the present invention, which is 420 to 480 nm It shows high absorption peak in the region and strong emission peak in 500 nm-650 nm region.

4 is a strontium sulfide red light-emitting phosphor according to an embodiment of the present invention: The fluorescent material 425 as referring to the absorption and emission spectra of _{(Sr 0 .99 S Eu 0 .01} ) - shows the absorption peaks in the 530 nm region And an emission peak in the 500-700 nm region.

In the case of a diode using a blue chip, the light energy emitted from these chips excites the phosphor, thereby allowing a warm white to be realized. This shows that the yellow phosphor and the red phosphor are suitable for applications in which these wavelength bands are energy sources.

FIG. 5 shows light emission spectra of a white light emitting diode in which a yellow phosphor, a red phosphor, and a blue light emitting device of the present invention are combined. As shown in FIG. 5, it can be seen that a warm white light (a) is realized by mixing the reference light generated from the blue chip and a part of the emitted light with yellow light and red light, which are the second light emitted and absorbed by the phosphor. .

In other words, the warm white color can be realized by the reference light generated from the blue light emitting element and the yellow and red light emitting phosphors which absorb and emit a part of the reference light. Therefore, the cold light obtained by combining the YAG: Ce yellow light emitting phosphor with the blue light emitting element is Compared with the white light (b), it is suitable for lighting in which warm white light is required by producing warm light having less green content and more red content.

FIG. 6 is a color coordinate illustrating a color gamut that can be realized by a light emitting diode in which a yellow light emitting phosphor, a red light emitting phosphor, and a blue light emitting element of the present invention are combined. As shown in FIG. 6, by adjusting the content of the yellow and red light emitting phosphors applied to the blue light emitting device, color coordinates of the selected region can be realized.

As shown, the ① area is the entire color coordinate area that can be realized by the yellow and red phosphors contained in the wavelength of the blue light emitting device to be applied and the phosphor coating layer used in the coating unit. Areas ② and ③ are warm white areas according to the present invention, which are implemented by changing the contents of the yellow phosphor and the red phosphor contained in the phosphor coating layer in combination with the light emitting device according to the wavelength of the blue LED chip applied.

The area ② is a case where a blue light emitting device having a relatively short wavelength is used, and the area ③ is a color coordinate area that can be realized when a blue light emitting device having a long wavelength is used.

In the phosphor coating layers 2 and 3, the yellow light-emitting phosphor may contain 0.01-70 parts by weight and preferably 10-20 parts by weight with respect to 100 parts by weight of the transparent resin so as to realize warm white. The red light-emitting phosphor may contain 0.01-60 parts by weight, preferably 25-40 parts by weight based on 100 parts by weight of the yellow light-emitting phosphor.

7 is a color reproduction range that can be implemented by a light emitting diode in which a yellow light emitting phosphor, a red light emitting phosphor and a blue light emitting element are combined according to the present invention, and a more specific color coordinate region, and area A is a color coordinate region of a conventional white light emitting device. Area B is the warm white color coordinate region of the present invention.

According to the content of the yellow and red phosphors emitted by the blue LED, any area within the area of FIG. 7 can be realized. For example, if the content of the two phosphors is small, the area is closer to the blue chip color coordinate area, and the content is increased. It can be seen that the color coordinates can be moved with. Region A in FIG. 8 is a warm color coordinate region implemented by mixing color of a suitable blue LED and two suitable phosphors.

The present invention is not limited to the above-described embodiment, and many modifications are possible by those skilled in the art within the technical spirit of the present invention defined by the appended claims.

As described above, the lighting white light emitting device having the yellow light emitting phosphor and the red phosphor according to the present invention absorbs a part of the blue light illuminated from the blue light emitting element, and combines the yellow and red light emitting elements that emit yellow and red light, thereby providing a warmth. White light can be illuminated. This white light emitting device is also excellent in brightness and color reproducibility. Therefore, it can be used as a light source for indoor lighting, interior lighting, portable lighting, and the like, in which warm white light is required.

Claims (13)

A light emitting white light emitting device comprising a blue semiconductor light emitting element, and a phosphor coating layer formed on the light emitting element, The phosphor coating layer is a terbium-borate-based yellow light-emitting phosphor represented by the following Chemical Formula 1, which emits light having a wavelength different from that of the light absorbed by absorbing the light emitted by the semiconductor light emitting device. Lighting white light emitting device comprising a red light emitting phosphor which is any one compound selected from the group consisting of compounds represented by 2 to 4: (Formula 1) (Tb _1-xyz RE _x A _y ) ₃ D _a B _b O ₁₂ : Ce _z In the above formula, RE is at least one rare earth element selected from the group consisting of Y, Lu, Sc, La, Gd, Sm, Pr, Nd, Eu, Dy, Ho, Er, Tm and Yb, and A is Li, Na, Is a metal element of at least one typical element selected from the group consisting of K, Rb, Cs and Fr, D is an amphoteric element of at least one typical element selected from the group consisting of Al, In and Ga, 0 ≦ x <0.5, 0 <y <0.5, 0 <z <0.5, 0 <a <5, and 0 <b <5, (Formula 2) (Sr _1-X ) S: Eu _X In Formula 2, the study agent Eu is set to a ratio within the range of 0.001≤X≤0.1mol, (Formula 3) (Ca _1-x S): Eu _X In Formula 3, the study agent Eu is set to a ratio within the range 0.001≤X≤0.1 mol, (Formula 4) (Ca _1-X ) ₂ Si ₅ N ₅ : Eu In Formula 4, the study agent Eu is set to a ratio within the range 0.001≤X≤0.2 mol. The white light emitting device of claim 1, wherein the terbium borate-based yellow light-emitting phosphor of Formula 1 is 0 <x + y + z <1 and 4 ≦ a + b ≦ 7. The illuminating white light emitting device of claim 1, wherein the yellow light emitting phosphor exhibits an absorption peak in a range of about 420 nm to 480 nm and a light emission peak in a range of about 500 nm to 650 nm. The white light emitting device of claim 1, wherein the red phosphor is any one compound selected from the group consisting of SrS: Eu, CaS: Eu, and Ca ₂ Si ₅ N ₈ : Eu. The white light emitting device of claim 1, wherein the red phosphor exhibits an absorption peak in a range of about 425 nm to 530 nm and a light emission peak in a range of about 500 nm to 700 nm. The white light emitting device of claim 1, wherein each of the yellow phosphor and the red phosphor has a spherical shape, a polygonal shape, or a plate shape, and has a particle size in the range of 0.1 to 50 μm. The method according to claim 1, wherein the phosphor coating layer comprises from 0.01 to 70 parts by weight of the yellow light-emitting phosphor with respect to 100 parts by weight of the transparent resin, the red light-emitting phosphor comprises from 0.01 to 60 parts by weight based on 100 parts by weight of the yellow light-emitting phosphor A white light emitting device for illumination. The white light emitting device of claim 1, wherein the transparent resin is at least one resin selected from the group consisting of an epoxy resin and a silicone resin. The white light emitting device of claim 1, wherein the blue semiconductor light emitting device has an emission spectrum peak of 400 nm to 530 nm. The method of claim 1, wherein the blue semiconductor light emitting device, Board; And And a light emitting layer formed on the substrate, the light emitting layer comprising at least one nitride semiconductor compound selected from the group consisting of GaN, InGaN, AlGaN, and AlInGaN. The white light emitting device of claim 10, wherein the substrate is sapphire or silicon carbide. The method according to any one of claims 1 to 11, A mount lead including a lead and a recess on the top of the lead; An LED chip positioned in the recess portion, the positive electrode and the negative electrode of which are connected to leads of the mount lead by metal wires, respectively, and emit UV or blue light; A phosphor coating layer filled in the recess to cover the LED chip; And And an exterior member sealing the mount lead portion except the lower portion of the mount lead and the LED chip and the phosphor coating layer. Terbium borate-based yellow light emitting phosphor represented by the following Chemical Formula 1, wherein the phosphor coating layer absorbs the light emitted by the semiconductor light emitting device and emits light having a wavelength different from that of the absorbed light; The white light emitting device for illumination comprising a red light emitting phosphor which is any one compound selected from the group consisting of compounds represented by 4 to: (Formula 1) (Tb _1-xyz RE _x A _y ) ₃ D _a B _b O ₁₂ : Ce _z In the above formula, RE is at least one rare earth element selected from the group consisting of Y, Lu, Sc, La, Gd, Sm, Pr, Nd, Eu, Dy, Ho, Er, Tm and Yb, and A is Li, Na, Is a metal element of at least one typical element selected from the group consisting of K, Rb, Cs and Fr, D is an amphoteric element of at least one typical element selected from the group consisting of Al, In and Ga, 0 ≦ x <0.5, 0 <y <0.5, 0 <z <0.5, 0 <a <5, and 0 <b <5, (Formula 2) (Sr _1-X ) S: Eu _X In Formula 2, the study agent Eu is set to a ratio within the range of 0.001≤X≤0.1mol, (Formula 3) (Ca _1-x S): Eu _X In Formula 3, the study agent Eu is set to a ratio within the range 0.001≤X≤0.1 mol, (Formula 4) (Ca _1-X ) ₂ Si ₅ N ₅ : Eu In Formula 4, the study agent Eu is set to a ratio within the range 0.001≤X≤0.2 mol. The method according to any one of claims 1 to 11, A casing having a recess in an upper portion thereof and equipped with a metal terminal; It is mounted in the recess, the positive electrode and the negative electrode are connected to the metal terminal by a metal wire, respectively, UV or An LED chip emitting blue light; And And a phosphor coating layer filled in the recess to cover the LED chip to bury the metal wire, wherein the phosphor coating layer has a wavelength of light absorbed and absorbed by the transparent resin and the light emitted by the semiconductor light emitting device. Terbium borate-based yellow light emitting phosphor represented by the following Chemical Formula 1, which emits light having a different wavelength, and a red light emitting phosphor comprising any one compound selected from the group consisting of compounds represented by the following Chemical Formulas 2 to 4 White light emitter: (Formula 1) (Tb _1-xyz RE _x A _y ) ₃ D _a B _b O ₁₂ : Ce _z In the above formula, RE is at least one rare earth element selected from the group consisting of Y, Lu, Sc, La, Gd, Sm, Pr, Nd, Eu, Dy, Ho, Er, Tm and Yb, and A is Li, Na, Is a metal element of at least one typical element selected from the group consisting of K, Rb, Cs and Fr, D is an amphoteric element of at least one typical element selected from the group consisting of Al, In and Ga, 0 ≦ x <0.5, 0 <y <0.5, 0 <z <0.5, 0 <a <5, and 0 <b <5, (Formula 2) (Sr _1-X ) S: Eu _X In Formula 2, the study agent Eu is set to a ratio within the range of 0.001≤X≤0.1mol, (Formula 3) (Ca _1-x S): Eu _X In Formula 3, the study agent Eu is set to a ratio within the range 0.001≤X≤0.1 mol, (Formula 4) (Ca _1-X ) ₂ Si ₅ N ₅ : Eu In Formula 4, the study agent Eu is set to a ratio within the range 0.001≤X≤0.2 mol.

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