KR20060063511A - White light emitted device using green-emitting and yellow emitting phosphor - Google Patents

Abstract

The present invention relates to a white light source having a yellow-green, green or orange light emitting material which is used in a light emitting diode and an active light emitting liquid crystal display and is excited and emitted in a blue or ultraviolet region, and more particularly, a silicate. A white semiconductor light-emitting device employing a white or strontium gallium-based green phosphor and a terbium aluminium-based yellow phosphor to enable white light emission by mixing blue light emitted from a light emitting element with green light and yellow light excited by the blue element and emitting light. to be.

White semiconductor light emitting device, silicate green phosphor, strontium gallium sulfide green phosphor, terbium aluminate yellow phosphor

Description

White light emitting device using green-emitting and yellow emitting phosphor

1 is a graph showing the absorption and emission spectrum of the barium silicate-based green phosphor of the present invention,

Figure 2 is a graph showing the absorption and emission spectrum of the strontium gallium sulfide-based green phosphor of the present invention,

3 is a graph showing the absorption and emission spectra of the terbium aluminate-based yellow phosphor of the present invention;

4 is a schematic configuration diagram of a lead-type white semiconductor light emitting device using barium silicate-based or strontium gallium sulfide-based green phosphors and terbium aluminate-based yellow phosphors of the present invention;

FIG. 5 is a schematic configuration diagram of a surface mount type white semiconductor light emitting device of a reflector injection structure type utilizing a barium silicate-based or strontium sulfide-based green phosphor and a terbium aluminate-based yellow phosphor of the present invention;

Figure 6 is a white light emitting diode emission spectrum by mixing with the emitted light of the terbium-aluminum-based yellow phosphor that absorbs some light emitted by the blue light emitting diode of the present invention to emit yellow light,

7 is a light emission of the barium silicate-based or strontium sulfide gallium-based green phosphor which absorbs partial light emitted by the blue light emitting diode of the present invention and emits green light, and the emitted light of the terbium-aluminum-based yellow phosphor which emits yellow light Emission spectrum of a white light emitting diode,

Fig. 8 shows a range of possible color reproduction by mixing the green light of the barium silicate or strontium gallium sulfide green phosphor which absorbs and emits some light emitted by the blue light emitting diode of the present invention with the yellow light of the terbium aluminate yellow phosphor. It is shown.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a white semiconductor light emitting device, and in particular, a blue reference light emitted from a light emitting layer of a semiconductor light emitting device, and a barium silicate or strontium gallium sulfide green phosphor and aluminum acid capable of absorbing a part of the emitted light and emitting green light. By containing a yttrium-based or terbium-aluminum-based yellow phosphor, semiconductor light emission capable of absorbing white light by a mixture of light from green and yellow phosphors that absorbs and excites a portion of blue light emitted by the semiconductor light emitting device and emits light Relates to a device.

A semiconductor light emitting diode, that is, a light emitting diode (Light Emitting Diode) is basically a semiconductor PN junction diode, an optoelectronic device that emits energy corresponding to the band gap of the semiconductor in the form of light by combining electrons and holes when a voltage is applied. Whereas silicon PN junctions were the protagonists of the electronic information revolution, PN junctions of III-V compound semiconductors are the protagonists of the light revolution.

Currently, technology for implementing white using InGaN-based light emitting devices has been actively conducted worldwide. The method can be summarized into two categories. For example, a technology of realizing white by containing a fluorescent material on a blue chip or a UV light emitting diode chip in the form of a single chip and a method of realizing white by combining two or three light emitting diode chips in a multi-chip form to obtain white. This is mainstream.

In the late 1996, a method of incorporating a phosphor into a single chip was carried out to commercialize high-brightness blue light emitting diodes. Thus, a blue phosphor was used as a reference light source to excite and emit a yellow phosphor to emit white light by mixing blue and yellow. I am using an implementation method. Examples of those known as current white semiconductor light emitting devices include the following.

Nichia's U.S. Patent Nos. 5,998,925 and 6,069,440 disclose YAG-based yellow fluorescent materials which absorb blue light and other long-wavelength light by absorbing a part of the light emitted by the blue light emitting device containing the nitride semiconductor and the blue light emitting device. A light emitting device is disclosed.

US Patent 6,504, 179 to Osram Corporation discloses a white light emitting device containing a blue light emitting device and a TAG-based yellow fluorescent material.

However, in case of TAG type, yellow orange light is emitted and white light is not formed by mixing with blue light. Therefore, green phosphor is added and mixed. When green phosphor is added, green phosphor is low in efficiency. There is a problem that the overall luminous intensity is lowered.

The present invention comprises a blue light emitted by a blue light emitting element and a part of the blue light by containing a high efficiency barium silicate or strontium gallium sulfide green phosphor and a terbium aluminate yellow phosphor in a light transmitting resin layer of a light emitting element having a blue light emitting chip. The present invention provides a white semiconductor light emitting device having excellent optical characteristics and color reproducibility by mixing a green light of a barium silicate-based or strontium gallium sulfide-based green phosphor that absorbs and emits light.

In order to achieve the above object, in the present invention, a white semiconductor having excellent optical characteristics and color reproducibility by applying green and yellow phosphors to a blue light emitting diode element to absorb blue light of a blue light emitting element as a reference light to emit green and yellow light Provide light emitting device:

<package>

In the present embodiment, the metal base of the package is formed by joining a metal thin plate constituting the terminal of the positive electrode and a metal thin plate constituting the terminal of the negative electrode with an insulating resin, respectively, and the positive electrode and the negative electrode of the light emitting diode chip. It is connected to the negative electrode by a wire.

Here, the light emitting diode chip is die-bonded by die-bonding resin on one metal thin plate. However, in the present invention, the light emitting diode chip may be die-bonded on the other metal thin plate or may be die-bonded over the metal thin plate and the metal thin plate.

〈Light Emitting Diode Chip〉

Since the blue light emitting diode of the present embodiment is configured to convert a part or all of the light in the light emitting diode chip into a wavelength by a fluorescent material, the blue light emitting diode chip emits light having a light emission wavelength capable of exciting the fluorescent material. Use it. In the present invention, it is preferable to use a light emitting diode chip using a nitride semiconductor (InAlGa) capable of emitting light of a short wavelength capable of efficiently exciting a fluorescent material. The blue light emitting diode chip has an InGaN light emitting layer, and the light emission wavelength can be arbitrarily changed from about 430 nm to 480 nm by the mixed crystal composition. Examples of the structure of the light emitting diode chip include a homo structure, a hetero structure, or a double hetero structure having a MIS junction, a PIN junction, a PN junction, and the like. In the present invention, any one can be used, but a double hetero can be obtained having a higher luminance. It is preferable to employ a structure. In addition, various light emission wavelengths can be selected depending on the composition of the semiconductor constituting the light emitting layer (active layer) and the degree of mixing thereof. In addition, the active layer may have a single quantum well structure or a multi quantum well structure including a thin film having a quantum effect.

In the case of a light emitting diode chip using a nitride semiconductor, materials such as sapphire, spinel, SiC, Si, ZnO, etc. may be used as the substrate. However, in order to form a nitride crystal with good crystallinity with good productivity, a sapphire substrate is used. desirable.

<Phosphor>

A barium silicate-based or strontium gallium sulfide-based green phosphor and a terbium aluminate-based yellow phosphor applied to the semiconductor light emitting device will be described.

Phosphors used in the semiconductor light emitting device of the present invention are green and yellow phosphors which are excited by ultraviolet light emitted from the semiconductor light emitting layer and an energy source in the visible region, and emit light having a wavelength different from that of the excitation light. Specifically, the barium silicate-based green phosphor is represented by the general formula (Ba _1-pq , M _p ) ₂ SiO ₄ : E _q , and M is at least one element selected from Sr, Ca, Mg, K, Na, and Ba. ≤ p <1 and 0 <q <0.5.

Preferably it is 0 <p + q <1, More preferably, it is 0.2 <p + q <0.7. Moreover, it is preferable that 0.1 <p <0.7, 0.0005 <q <0.2.

In the above general formula, it is possible to obtain a preferable luminous efficiency when p and q are in the numerical range. In addition, when q is in the above numerical range, Eu 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 strontium gallium sulfide-based green phosphor is described in more detail by the general formula (Sr _{1-p'-q '} , M _p' ) Ga ₂ S ₄ : Eu _{q '} , and M is represented by Sr, Ca, Mg, K, At least one element selected from Na and Ba is 0 ≦ p '<0.5 and 0 <q'<0.5.

Preferably it is 0 <p '+ q' <1, More preferably, it is 0 <p '+ q' <0.5. In addition, it is preferable that 0.05 <p '<0.3 and 0.0005 <q' <0.1.

In the above general formula, when p 'and q' are in the numerical range, preferable luminous efficiency can be obtained. In addition, when q 'is within the above numerical range, Eu 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 green phosphor exhibits an absorption peak in the range of about 400 nm to 500 nm and an emission peak of about 500 nm to 600 nm.

In the case of terbium aluminate yellow phosphor, the general formula (Tb _1-a X _a ) ₃ Al ₅ O ₁₂ : Ce _b and X is at least one selected from the group consisting of Y, Lu, Sc, La, Gd and Sm It is an element, and it is preferable to set it to the ratio of 0 <a <1 and 0.001 <= b <0.5. In the above general formula, a preferable luminous efficiency can be obtained when a and b are in the numerical range. In addition, when b 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 decrease due to a quenching effect may occur. The yellow phosphor exhibits an absorption peak in the range of about 400 nm to 500 nm and an emission peak of about 460 nm to 700 nm.

The green and yellow phosphors as described above are filled in a reflective cup formed of a hole cup or a plastic injection molding, including a blue LED chip upper surface, included in a transparent epoxy resin layer or a transparent silicone resin layer in manufacturing a white semiconductor light emitting device. The barium silicate or strontium sulfide gallium green phosphor and the terbium aluminate yellow phosphor included in the transparent epoxy resin layer or the transparent silicone resin layer are based on the inner bottom surface of the reflection cup formed of a hole cup or a plastic injection according to the particle size (particle size). It consists of large particles, medium particles, and small particles, and the green and yellow phosphors of the transparent epoxy resin layer or the transparent silicone resin layer are preferably settled and cured so as to sufficiently fill the mold material. When the phosphor is sufficiently settled in the transparent epoxy resin layer or the transparent silicone resin layer to harden the mold material, the light generated from the semiconductor light emitting element is absorbed by the phosphor particles, and the light path difference that scatters and disappears is reduced, thereby It is possible to increase the intensity of the white light as well as to uniformly emit white light. However, when the phosphor particles solidify and overlap with each other in a suspended state without sufficient sedimentation, the light generated from the semiconductor light emitting device is close to the surface of the LED chip. Partially suspended phosphor particles are absorbed by the phosphor and emitted as excited secondary light, but the excited secondary emission light hits the phosphor particles away from the chip surface along the path and does not contribute to light emission, and some transmit And part of it is reflected and diffused, and part of it is extinguished, which significantly lowers the luminous intensity. Thereby. In the present invention, the particle size (particle size) of the barium silicate-based or strontium-gallium-based green phosphor and the terbium-aluminum-based yellow phosphor contained in the transparent epoxy resin layer or the transparent silicone resin layer, the large particles and the medium particle phosphor size is 2 The small particle fluorescent substance size is set in the range of 0.1 µm to 2 µm. Since the phosphor mainly emits light on the surface of the powder, the smaller the particle size, the more the surface area of the powder increases and the emission intensity increases, but when the particle size becomes smaller than a certain limit (for example, less than 0.1 μm), the scattered light It is extinguished by the optical path difference absorbed between the particles, and also does not sufficiently settle in the transparent epoxy resin layer or the transparent silicone resin layer, so that the aggregates are easily formed in a suspended state, and thus the luminous intensity is lowered. In addition, if the particle size is larger than the limit (for example, larger than 50 μm), the sedimentation rate is accelerated, the fluorescent material layer is thickened and overlaps with each other, so that the ratio of fluorescent materials that do not contribute to light emission is increased, resulting in a decrease in emission intensity. . That is, in the sedimentation by the particle size (particle size), the LED chip is filled with large particles and medium particle phosphors having a particle size in the range of 2 μm to 50 μm based on the inner bottom surface of the reflection cup formed of a hole cup or a plastic injection product. It is possible to further increase the luminous intensity and to enable uniform white light emission by disposing small particle phosphors which are present in the vicinity of and do not overlap the particle size having a particle size in the range of 0.1 µm to 2 µm.

As described above, the semiconductor light emitting device described above is a combination of a gallium nitride-based (AllnGaN) compound semiconductor device capable of emitting blue light, a barium silicate or strontium gallium sulfide green phosphor, and a terbium aluminate yellow phosphor. By mixing blue light emitted from the light and green and yellow light emitted from the phosphor excited by the light emission, white light having excellent optical characteristics and color reproducibility can be realized.

As the light emitter of the white semiconductor light emitting device, organic and inorganic phosphors may be used. The inorganic phosphor guarantees higher chemical stability, temperature stability, and light stability than the organic phosphor.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention.

1 is a graph showing the absorption and emission spectrum of the barium silicate-based green phosphor of the present invention, the (Ba _1-xy , M _x ) ₂ SiO ₄ : Eu _y green phosphor to be used in the present invention is a representation of the exact structural formula (Ba _0.79 Sr _0.2 ) ₂ SiO ₄ : Eu _0.1 . Since Eu ²⁺ ions are composed of substitution forms at Ba ²⁺ positions, strontium nitride, barium nitride, silicate oxide and europium nitride are used in a stoichiometric ratio for synthesis.

In the absorption and emission spectrum shown in FIG. 1, (Ba _0.79 Sr _0.2 ) ₂ SiO ₄ : Eu _0.1 has excellent absorption characteristics from 440 nm to 470 nm, which is the emission region of the blue light emitting diode, and excellent emission from 500 nm to 650 nm. It can be seen that it shows characteristics.

Figure 2 is a graph showing the absorption and emission spectrum of the strontium gallium sulfide-based green phosphor of the present invention, the expression of the exact structural formula of the SrGa ₂ S ₄ : Eu phosphor to be used in the present invention is Sr _0.95 Ga ₂ S ₄ : EU _0.05 to be. Since Eu ²⁺ ions are composed of substitution forms in the position of Sr ²⁺ , strontium sulfide, gallium nitride, sulfur and europium sulfide are used in a stoichiometric ratio.

In the absorption and emission spectrum shown in FIG. 2, Sr _0.95 Ga ₂ S ₄ : Eu _0.05 has excellent absorption characteristics of 470nm to 470nm, which is the emission region of the blue light emitting diode, and shows excellent emission characteristics of 500nm to 650nm. It can be seen.

3 is a graph showing the absorption and emission spectra of the terbium aluminate-based yellow phosphor of the present invention, the (Tb _1-a X _a ) ₃ Al ₅ O ₁₂ : Ce _0.01 phosphor to be used in the present invention is represented by the exact structural formula (Tb _1-a X _a ) ₃ Al ₅ O ₁₂ : Ce _0.01 . Since Ce ³⁺ ions are composed in the substitution form at the Tb ³⁺ position, terbium oxide, aluminum nitride and cerium oxide are used in a stoichiometric ratio.

In the absorption and emission spectrum shown in FIG. 3, (Tb _1-a X _a ) ₃ Al ₅ O ₁₂ : Ce _0.01 has excellent absorption characteristics of 470 nm to 470 nm, which is the emission region of the blue light emitting diode, and at 500 nm. It can be seen that the excellent emission characteristics of 650nm.

4 is a schematic block diagram of a lead type white semiconductor light emitting device using barium silicate or strontium gallium sulfide green phosphor and terbium aluminate yellow phosphor as an embodiment of the present invention. The lead type white semiconductor light emitting device of the present invention may be applied to a light emitting diode having a cup-shaped reflector or similar structure as a conventional structure. Electrical connection is possible by connecting the LED chip 8, the anode lead 9, and the cathode lead 10 with conductive wires 11, respectively. Barium silicate-based or strontium-gallium-based green fluorescent substance having a transparent epoxy resin layer or a transparent silicone resin layer 13 inside the cup so that the LED chip is positioned inside the cup of the cathode lead 10 and surrounds the LED chip. And a mold member 14 formed of a terbium aluminate-based yellow phosphor and coated with a transparent or colored translucent resin around the transparent resin layer.

According to the present invention, the transparent epoxy resin layer or the transparent silicone resin layer is a barium silicate-based or strontium-gallium sulfide-based green phosphor and a terbium-aluminum yellow in the light emitting path of the blue light emitting device. It is characterized in that the phosphor is included.

The particle size of the green and yellow phosphors contained in the mold layer of the present invention is preferably in the form of a mixture of large particles, medium particles and small particles. And it is more preferable to distinguish particle sizes of green and yellow phosphors. For example, if the green phosphor particle size is selected as a large particle or a medium particle and the yellow phosphor is selected as a small particle, or if the yellow phosphor is selected as a large particle or a medium particle and the green phosphor is selected as a small particle, the luminance is 10% or more than when there is no particle size classification. There was an improvement.

FIG. 5 is a schematic block diagram of a surface mount type white semiconductor light emitting device having a reflector injection structure using a barium silicate or strontium gallium sulfide green phosphor and a terbium aluminate yellow phosphor as another embodiment of the present invention. .

As shown in FIG. 5, the light emitting diode is electrically connected by connecting the blue LED chip 1, the anode terminal 3, and the cathode terminal 2, respectively, and is made of a transparent epoxy resin layer or transparent silicon. It has the conventional structure containing the resin layer 4 and the reflecting plate 5 of the cup form of the opaque resin material which has a reflection function. The reflective surface 6 is formed on the inner side of the reflector 5, and the anode terminal and the cathode terminal are connected to the N-type electrode and the P-type electrode of the LED chip with a conductive wire (Au wire, 7), respectively, so that the electrical connection is made. It is possible. The transparent epoxy resin layer or the transparent silicone resin layer 4 is characterized in that the barium silicate-based or strontium gallium-based green phosphor and the terbium-aluminum-based yellow phosphor are laminated in the light emitting path of the blue light emitting device as a feature of the present invention. do.

The particle size of the green and yellow phosphors contained in the mold layer of the present invention is preferably in the form of a mixture of large particles, medium particles and small particles. And it is more preferable to distinguish particle sizes of green and yellow phosphors. For example, if the green phosphor particle size is selected as a large particle or a medium particle, the yellow phosphor is selected as a small particle, or when the yellow phosphor is selected as a large particle and a medium particle, and the green phosphor is selected as a small particle, the luminance is 15% or more than when there is no particle size classification. There was an improvement.

6 and 7 illustrate a white light emitting diode emission spectrum and blue light due to mixing with light emitted by a terbium aluminate yellow phosphor which absorbs some light emitted by a blue light emitting diode and emits yellow light. Light emission spectrum of a white light emitting diode in which the emitted light of a barium silicate or strontium sulfide gallium green phosphor which emits green light by absorbing some light emitted by the light emitting diode and a terbium aluminum sulfate phosphor that emits yellow light is mixed and emits light It is shown.

The emission spectrum shown in FIG. 6 is formed by white light mixed by a single tungsten aluminum TAG phosphor and blue light, indicating that x = 0.296 and y = 0.252 color positions are formed, thereby making it impossible to form excellent white light. The emission spectrum shown in Fig. 7 contains the barium silicate-based or strontium sulfide gallium-based green phosphor of the present invention, and thus the barium silicate-based or strontium gallium sulfide which absorbs and emits part of the blue light emitted by the blue light-emitting device. By mixing the green light of the green phosphor and the yellow light of the terbium aluminate yellow phosphor, white light having excellent color characteristics of x = 0.298 and y = 0.280 can be realized. In particular, by arranging the phosphors having a particle size in the range of 0.1 μm to 30 μm so as not to overlap each other, it is possible to increase the emission intensity as well as to enable uniform white light emission.

FIG. 8 illustrates a color reproduction range of green light of a barium silicate or strontium gallium sulfide green phosphor that absorbs and emits some light emitted by a blue light emitting diode and yellow light of a terbium aluminate yellow phosphor. Color coordinates shown. As shown in Fig. 8, by adjusting the contents of the barium silicate-based or strontium-gallium-based green phosphor that absorbs some light of the blue LED chip and emits green light, and the terbium-aluminum-based yellow phosphor that emits yellow light, It is possible to implement color coordinates of the designated area.

The regions ① to ④ shown in FIG. 8 can be implemented by changing the weight percent of the yellow and green phosphors contained in the transparent epoxy resin layer or the transparent silicone resin layer. It can be implemented by containing 5-10% of yellow phosphor and 2-5% of green phosphor, and the area is 15-20% of yellow phosphor and 5-8% of transparent epoxy resin layer or transparent silicone resin layer. It can be realized by containing the green phosphor of (3). Also, the region contains 18 to 25% of the green phosphor and 2 to 5% of the yellow phosphor contained in the transparent epoxy resin layer or the transparent silicone resin layer used for the coating part. ④ region is 10-15% of green type with respect to the transparent epoxy resin layer or the transparent silicone resin layer used for the coating part. Body and by containing the yellow phosphor of 2-5% can be implemented. Therefore, in the region selected in FIG. 8, a color within a solid line can be realized by appropriately adjusting the contents of the barium silicate-based green phosphor and the terbium aluminate-based yellow phosphor in the transparent epoxy resin layer or the transparent silicone resin layer.

As described above, the white light emitting diode having the barium silicate-based or strontium sulfide-based green phosphor and the terbium aluminate-based yellow phosphor according to the present invention can realize a white light having excellent optical properties and color reproducibility under excitation in the visible region. Applications of LED applications using light emitting devices and the blue band as energy sources are suitable.

The present invention is not limited to the above-described embodiment, and it will be apparent that many modifications are possible by those skilled in the art within the technical spirit of the present invention.

Claims (12)

And a green phosphor, a yellow phosphor, and a transparent mold material which absorb a portion of light emitted by a GaN, InGaN, AlGaN, or AlGaInN series blue semiconductor light emitting diode and emit light having a wavelength different from that of the absorbed light. A white semiconductor light emitting device that emits white light by mixing emission light of a fluorescent material excited on a blue LED and a part of blue LEDs. The fluorescent material is a white semiconductor light emitting device, characterized in that the barium silicate or strontium gallium sulfide-based green phosphor and terbium-based yellow phosphor. The method of claim 1, The light emitting device is a white semiconductor light emitting device comprising a blue light emitting device of GaN, InGaN, AlGaN, AlGaInN series. The method of claim 1, The green phosphor contained in the light-transmitting mold material is a barium silicate-based and / or strontium sulfide-based activated bivalent euroform; (Ba _1-pq , M _p ) ₂ SiO ₄ : Eu _q and / or (Sr _{1-p'-q '} , M _p' ) Ga ₂ S ₄ : Eu _{q '} Specifically, barium silicate-based and / or strontium gallium sulfide-based green phosphors are represented by general formula, and M is selected from the group consisting of at least one element selected from Sr, Ca, Mg, K, Na, and Ba. White semiconductor light emitting device. The method of claim 1, The yellow phosphor contained in the light-transmissive mold material is terbium aluminate, activated by trivalent cerium; (Tb _1-a X _a ) ₃ Al ₅ O _l2 : Ce _b Specifically, a terbium aluminate-based yellow phosphor is represented by a general formula, and X is selected from the group consisting of Y, Lu, Sc, La, Gd, and Sm. The method of claim 1, The semiconductor light emitting device is a white semiconductor light emitting device, characterized in that the lead frame is formed in a cup shape, the blue LED chip is a lead type formed by connecting the anode terminal and the cathode terminal with a conductive wire (Au wire). The method of claim 1, The semiconductor light emitting device includes a reflector injection structure type surface-mounted white semiconductor light emitting device in which an LED chip is formed by connecting an anode terminal and a cathode terminal with a conductive wire in a reflection cup formed of plastic injection. The method of claim 1, The transparent resin of the phosphor coating layer is a white semiconductor light emitting device, characterized in that the transparent epoxy resin or silicone resin. The method of claim 1, The barium silicate or strontium sulfide gallium green phosphor and the terbium aluminate yellow phosphor have spherical particles or flakelike particles, and the particle size ranges from 0.1 μm to 50 μm. A white semiconductor light emitting device. The method of claim 1, The particle size of the phosphor contained in the mold layer is characterized in that the particle size of the green phosphor and yellow phosphor is uniformly used or divided into large particles, medium particles and small particles, specifically, the particle size of the green phosphor large particles and heavy particles (2 Μm to 50 μm) and yellow phosphors are used as small particles (0.1 μm to 2 μm) or yellow phosphors are used as large particles and medium particles (2 μm to 50 μm) and green phosphors are small particles (0.1 μm to 2 μm). And a white semiconductor light emitting device, characterized in that used. The method of claim 1, The LED has a main peak of its emission spectrum in the range of 400 nm to 500 nm, and the main emission wavelength peak of the green and yellow phosphors is longer than the main emission wavelength peak of the LED light emitting device. A green phosphor and a yellow phosphor, which absorb a portion of the light emitted by the blue semiconductor light emitting element and emit light having a wavelength different from that of the absorbed light, are contained together with the translucent mold resin to form a coating layer. The green phosphor is a barium silicate-based and / or strontium gallium sulfide-based green phosphor activated by divalent europium: (Ba _1-pq , M _p ) ₂ SiO ₄ : Eu _q and / or (Sr _{1-p'-q '} , M _p' ) Ga ₂ S ₄ : Eu _{q '} Specifically, barium silicate-based green phosphor is represented by the general formula, M is selected from the group consisting of at least one element selected from Sr, Ca, Mg, K, Na, Ba, The yellow phosphor contained in the light transmitting mold material is terbium aluminate-based activated by trivalent cerium; (Tb _1-a X _a ) ₃ Al ₅ O ₁₂ : Ce _b Specifically, the aluminum terbium-based yellow phosphor is represented by a general chemical formula, and X is made of at least one element selected from the group consisting of Y, Lu, Sc, La, Gd and Sm. A display module and a mechanism device in which the white semiconductor light emitting devices according to any one of claims 1 to 10 are arranged in parallel or in series to be employed as a back light source.

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