JP6928287B2 - Manufacturing method of light emitting device - Google Patents

Description

The present invention relates to a method for manufacturing a light emitting device.

Various light emitting devices that emit white light with high color rendering properties have been developed by combining a light source such as a light emitting diode (LED) chip, a phosphor that emits green fluorescence, and a phosphor that emits red fluorescence. ing. As a phosphor that emits green (G), for example _{, a sulfide phosphor represented by the composition of SrGa 2} S ₄ : Eu is known, and as a phosphor that emits red (R), for example, K ₂ SiF ₆ : A fluoride phosphor represented by the composition of Mn is known.

Sulfide phosphors are known to cause a decrease in emission intensity and a chromaticity shift under high temperature and high humidity. This is because the sulfur contained in the sulfide phosphor easily reacts with the moisture in the atmosphere, and the hydrolysis reaction between the sulfur and the moisture produces metal hydroxides and hydrogen sulfide, which deteriorates the phosphor. it is conceivable that.

In order to suppress deterioration of the sulfide phosphor, Patent Document 1 proposes a light emitting device using a glass sheet containing oxide-coated phosphor particles in which the surface of the sulfide-based phosphor particles is coated with an oxide. ing. Although Patent Document 1 includes a solution method, a CVD method, and the like as a method for forming an oxide on sulfide-based phosphor particles, specifically, sulfide fluorescence coated with silicon dioxide by a solution method. An example using body particles is disclosed.

Japanese Unexamined Patent Publication No. 2008-115223

However, even when a sulfide phosphor according to the prior art is used, the moisture resistance of the light emitting device is not sufficiently improved, and deterioration of the sulfide phosphor causes chromaticity shift or light emission output of the light emitting device. The decrease is not suppressed.
Further, when a fluoride phosphor is used in a light emitting device together with a sulfide phosphor, not only the sulfide phosphor but also the fluoride phosphor easily reacts with moisture in the atmosphere, and the fluorine in the fluoride phosphor Hydrogen fluoride is generated by the reaction with water in the atmosphere, and not only the water but also this hydrogen fluoride deteriorates the sulfide phosphor, causing chromaticity shift and the decrease in the light emission output of the light emitting device cannot be suppressed. There is also a problem. It is conceivable to suppress the reaction with water by coating the fluoride phosphor with an oxide film or the like, but since the fluoride phosphor is sensitive to heat, it is difficult to form an oxide deposit or a film. Is.
The present invention uses a first phosphor containing a thiogallate phosphor having improved moisture resistance and hydrogen fluoride resistance, and a second phosphor which is a fluoride phosphor, and emits light even under high temperature and high humidity. It is an object of the present invention to provide a method for manufacturing a light emitting device capable of suppressing a decrease and suppressing a chromaticity deviation.

Specific means for solving the above problems are as follows, and the present invention includes the following aspects.
In the embodiment of the present invention, a film containing aluminum oxide is formed on particles made of thiogallate phosphor (hereinafter, also referred to as “thiogallate phosphor particles”) by a CVD method to emit fluorescence in the range of green to yellowish green. A step of obtaining a single phosphor, a light source that emits light having an emission peak wavelength in the range of 420 to 480 nm, the first phosphor, and fluoride fluorescence activated by manganese that emits fluorescence in the yellow-red to red range. It is a method of manufacturing a light emitting device, which includes a step of obtaining a light emitting device using a second phosphor which is a body.

According to the present invention, the moisture resistance and hydrogen fluoride resistance of the thiogallate phosphor particles are improved, and the first phosphor containing the thiogallate phosphor particles and the second phosphor which is a fluoride phosphor are used at a high temperature. It is possible to provide a method for manufacturing a light emitting device capable of suppressing a decrease in light emitting output and suppressing a color shift even under high humidity.

It is a schematic cross-sectional view which shows the light emitting device which concerns on one Embodiment. It is an SEM image of the first phosphor used in Reference Example 3. It is an SEM image of the cross section of the first phosphor used in Reference Example 3. It is an SEM image of the first phosphor used in Comparative Example 2. 6 is an SEM image of a cross section of the first phosphor used in Comparative Example 2. The results of elemental analysis (horizontal axis: energy (keV), vertical axis: count number) of the region marked with x in the SEM image of the first phosphor used in Reference Example 3 shown in FIG. 3 by the SEM-EDX method are shown. It is a figure which shows. The figure which shows the result (horizontal axis: energy (keV), vertical axis: count number) of the elemental analysis by the SEM-EDX method of the region marked with x in the SEM image of the phosphor used in the comparative example 2 shown in FIG. Is. 6 is an SEM image of the first phosphor used in Example 10. 6 is an SEM image of a cross section of the first phosphor used in Example 10. The results of elemental analysis (horizontal axis: energy (keV), vertical axis: count number) of the region marked with x in the SEM image of the first phosphor used in Example 10 shown in FIG. 9 by the SEM-EDX method are shown. It is a figure which shows.

Hereinafter, a method for manufacturing a light emitting device according to the present invention will be described with reference to embodiments and examples. However, the method for manufacturing the light emitting device shown below is for embodying the technical idea of the present invention, and does not specify the present invention as the following.
The relationship between the color name and the chromaticity coordinate, the relationship between the wavelength range of light and the color name of monochromatic light, and the like are in accordance with JIS Z8110.

The numerical range indicated by using "~" in the present specification indicates a range including the numerical values before and after "~" as the minimum value and the maximum value, respectively. Further, the content of each component in the composition means the total amount of the plurality of substances present in the composition when a plurality of substances corresponding to each component are present in the composition, unless otherwise specified. In the present specification, the term "process" is included in this term as long as the intended purpose of the process is achieved, not only in an independent process but also in the case where it cannot be clearly distinguished from other processes. Is done. Further, the content of each component in the composition means the total amount of the plurality of substances present in the composition when a plurality of substances corresponding to each component are present in the composition, unless otherwise specified.

(Corresponding to claim 1)
One aspect of the present invention is a step of forming a film containing aluminum oxide on thiogallate phosphor particles by a CVD method to obtain a first phosphor that fluoresces in the range of green to yellowish green, and in the range of 420 to 480 nm. A light emitting device is provided by using a light source that emits light having an emission peak wavelength, the first phosphor, and a second phosphor that is a fluoride phosphor activated with manganese that emits fluorescence in the yellow-red to red range. It is a method of manufacturing a light emitting device including a step of obtaining.

An example of the light emitting device thus obtained is shown in FIG. 1 as a light emitting device 100.

The step of obtaining the first phosphor 41 includes a step of forming a film containing aluminum oxide on the thiogallate phosphor particles by a CVD method. In the first phosphor 41, a film containing aluminum oxide is relatively uniformly formed on the entire surface of the thiogallate phosphor particles by the CVD method, so that the reaction between the sulfur contained in the thiogallate phosphor particles and the moisture in the atmosphere occurs. Not only is it suppressed, but the reaction with hydrogen fluoride generated from the fluoride phosphor is suppressed. A light emitting device using these first phosphors can suppress a decrease in luminous flux and a chromaticity shift due to deterioration over time even when the light emitting device is placed under high temperature and high humidity.

(Step of obtaining the first phosphor 41)
The first phosphor 41 contains thiogallate phosphor particles, and is preferably phosphor particles having a chemical composition represented by the following general formula (I).
(M1 _1-x M2 _x ) Ga _2-y S _4-z (I)
In formula (I), M1 is at least one element selected from the group consisting of Sr, Be, Mg, Ca, Ba and Zn, and M2 is at least selected from the group consisting of Eu and Ce. It is one kind of element, and x, y, and z satisfy 0.03 ≦ x ≦ 0.25, −0.2 ≦ y ≦ 0.2, and −0.2 ≦ z ≦ 0.2).

In the step of obtaining the first phosphor 41, it is preferable to form a film containing aluminum oxide by a fluidized bed CVD method. By the fluidized bed CVD method, a film containing aluminum oxide can be more uniformly formed on the entire surface of the thiogallate phosphor particles.

When a film containing aluminum oxide is formed on the thiogallate phosphor particles by the fluidized bed CVD method, a fluidized bed CVD apparatus for powder can be used. For example, thiogallate phosphor particles having thiogallate phosphor particles or deposits formed therein are put into a reaction tube of a fluidized layer CVD apparatus for powder, and trimethylaluminum (TMA) or the like is vaporized in an inert gas as a raw material. A CVD film containing aluminum oxide in the thiogallate phosphor particles (hereinafter, "" Also referred to as "chemical vapor deposition film").
The inert gas is a gas containing argon, helium, nitrogen or the like as a main component, and means a gas containing at least one of argon, helium and nitrogen in an amount of 85% by volume or more.
The reaction temperature is not particularly limited as long as it is a temperature equal to or higher than the boiling point of trimethylaluminum or the like as a raw material, but is preferably 125 ° C. to 450 ° C., more preferably 150 ° C. to 400 ° C.

In the step of obtaining the first phosphor 41, the film containing aluminum oxide may be formed in contact with the deposits formed on the surface of the thiogallate phosphor particles or the surface of the film, but may be formed in contact with the surface of the thiogallate phosphor particles. It is preferable to form. Since the surface of the thiogallate phosphor is smoother than the surface of the deposit or the surface of the film, the entire surface of the thiogallate phosphor particles can be coated with a relatively uniform film containing aluminum oxide by the CVD method. As a result, the reaction with moisture and hydrogen fluoride in the atmosphere is suppressed, so that the moisture resistance and hydrogen fluoride resistance of the first phosphor 41 are further improved.

In the step of obtaining the first phosphor 41, it is preferable to form an deposit containing silicon dioxide on the surface of the film containing aluminum oxide. As a result, the moisture resistance of the first phosphor 41 is further improved.

The deposit containing silicon dioxide is preferably formed by the sol-gel method. Thereby, a deposit containing an amount of silicon dioxide sufficient for improving the moisture resistance can be formed on the surface of the film containing aluminum oxide. When forming a film containing silicon dioxide by a method other than the sol-gel method, for example, the CVD method, it is necessary to use _{silicon tetrachloride (SiCl 4} ), tetramethyl orthosilicate (TMS: Si (OCH ₃ ) _{4), etc. as raw materials.} There is. However, when silicon tetrachloride is used as the raw material, the equipment may be damaged by the hydrochloric acid generated by the reaction, and when tetramethyl orthosilicate is used, the vapor pressure is low and it takes time to form a film. Not preferable because it is spent.

When the deposit containing silicon dioxide is formed by the sol-gel method, the thiogallate phosphor particles having formed the film containing aluminum oxide are dispersed in ethanol, and the silicon alkoxide is added to the alcohol mixed with the thiogallate phosphor particles to make it acidic or acidic. Adhesions containing silicon dioxide can be formed by hydrolyzing under basic conditions to desorb alcohol. Examples of the silicon alkoxide include tetraethyl orthosilicate (TEOS: Si (OC ₂ H ₅ ) ₄ ) and the like.

In the step of obtaining the first phosphor 41, the content of the aluminum element contained in the film containing aluminum oxide is preferably 0.2% by mass or more and 10% by mass or less in the first phosphor 41, more preferably. It is preferably 0.3% by mass or more and 8.0% by mass or less, and more preferably 0.4% by mass or more and 5.0% by mass or less. When the content of the aluminum element is more than a predetermined value, the moisture resistance and hydrogen fluoride resistance tend to be further improved, and when the content is less than the predetermined value, the moisture resistance and hydrogen fluoride resistance due to cracks in the film are generated. It is possible to suppress the decrease in sex.

In the step of obtaining the first phosphor 41, the content of the silicon element contained in the deposit containing silicon dioxide is preferably 0.5% by mass or more and 10% by mass or less in the first phosphor 41. It is more preferably 0.6% by mass or more and 9.0% by mass or less, and further preferably 0.8% by mass or more and 8.0% by mass or less. When the content of silicon element is more than a predetermined value, moisture resistance and hydrogen fluoride resistance tend to be further improved, and when it is less than a predetermined value, moisture resistance and hydrogen fluoride resistance due to cracks in the film are generated. It is possible to suppress the decrease in sex.

In the step of obtaining the first phosphor 41, the average value of the ratio of the thickness of the film containing aluminum oxide to the particle size of the first phosphor 41 is preferably 0.5% or more and 10% or less, more preferably 0. It is 7.7% or more and 9.0% or less, and more preferably 0.8% or more and 8.0% or less. When the average value of the thickness ratio of the film containing aluminum oxide is more than a predetermined value, the moisture resistance and hydrogen fluoride resistance tend to be further improved, and when it is less than the predetermined value, cracks occur in the film. It is possible to suppress a decrease in moisture resistance and hydrogen fluoride resistance.

In the step of obtaining the first phosphor 41, the average value of the ratio of the thickness of the deposit containing silicon dioxide to the particle size of the first phosphor 41 is preferably 0.5% or more and 10% or less, more preferably. It is 0.6% or more and 8.0% or less. When the average value of the thickness ratio of the deposit containing silicon dioxide is more than a predetermined value, the moisture resistance and hydrogen fluoride resistance tend to be further improved, and when it is less than the predetermined value, cracks occur in the film. It is possible to suppress a decrease in moisture resistance and hydrogen fluoride resistance due to the above.

The average particle size of the first phosphor 41 is preferably 3.0 μm or more and 20 μm or less, more preferably 4.0 μm or more and 15 μm or less, still more preferably 5.0 μm or more and 12 μm or less, and even more preferably. Is 5.0 μm or more and 10 μm or less. In the present specification, the average particle size of the first phosphor 41 is determined by the Fisher Sub-Sieve Sizer (FSSS) method using, for example, Fisher Sub-Sieve Sizer Model 95 (manufactured by Fisher Scientific). , The value of the average particle size measured as the Fisher Subsieving Sizar's Number (FSSSN).
When the average particle size is equal to or less than a predetermined value, the moisture resistance and hydrogen fluoride resistance tend to decrease, and when the average particle size is equal to or more than a predetermined value, production is difficult.

(Process to obtain light emitting device)
An LED chip made of a nitride semiconductor having an emission peak wavelength of 455 nm is arranged as the light source 10 on the bottom surface of the recess of the package 20, and the light source 10 and the first lead 21 and the second lead 22 are connected by wires 30, respectively. _{The first phosphor 41 obtained in the step of obtaining the first phosphor and the K 2} SiF ₆ : prepared in advance so that the CIE chromaticity coordinates x and y of the mixed color light emitted by the light emitting device have predetermined values. The second phosphor 42, which is Mn, is added to the resin and mixed and dispersed to obtain a phosphor-containing resin composition. An appropriate amount of this phosphor-containing resin composition is injected into the recess of the package 20 and the resin in the fluorescent composition is cured to form the fluorescent member 40. As a result, the light emitting device 100 shown in FIG. 1 can be obtained.

(Light emitting device)
The light emitting device 100 includes a package 20 that forms a recess, and a light source 10 that is arranged on the bottom surface of the recess. The package 20 has a first lead 21, a second lead 22, and a molded body 23, and a part of the surface of the first lead 21 and a part of the surface of the second lead 22 are formed on the bottom surface of the recess of the package 20. Is exposed from the molded body 23 at the bottom of the recess. The light source 10 is arranged on the first lead 21. The light source 10 has a pair of positive and negative electrodes, and the pair of positive and negative electrodes are electrically connected to the first lead 21 and the second lead 22 via a wire 30, respectively. The light source 10 is covered with a fluorescent member 40. The fluorescent member 40 contains a first phosphor 41 and a second phosphor 42 that wavelength-convert the light from the light source 10.

Hereinafter, each element constituting the light emitting device 100 will be described.

[Light source 10]
The emission peak wavelength of the light source 10 is in the range of 420 to 480 nm. By using the light source 10 having the emission peak wavelength in this range as the excitation light source of the phosphor, it is possible to configure the light emitting device 100 that emits the mixed color light of the light from the light source 10 and the fluorescence from the phosphor. As the light source 10, for example, _{an LED chip made of a nitride semiconductor (In X} Al _Y Ga _1-XY N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) can be used.

[Package 20]
The package 20 is formed by integrally forming the first lead 21, the second lead 22, and the molded body 23. In the present embodiment, the package 20 has a recess, and the light source 10 is arranged at the bottom thereof.

[First lead 21 and second lead 22]
The first lead 21 and the second lead 22 have conductivity and are for electrically connecting the light source 10 and the outside. The first lead 21 and the second lead 22 have, for example, a base material containing copper and a reflective film containing silver formed on the surface thereof.

[Molded product 23]
As the molded body 23, an electrically insulating one having excellent light resistance and heat resistance is used. As the material, resin, ceramics, etc. can be used.

[Wire 30]
The wire 30 electrically connects the positive electrode and the negative electrode of the light source 10 to the first lead 21 or the second lead 22, and is usually a metal such as gold, copper, platinum, or aluminum, or a metal thereof. The wire 30 using the alloy of the above can be used. In particular, it is preferable to use gold having excellent thermal resistance and the like for the wire 30.

[Fluorescent member 40]
The fluorescent member 40 covers the light source 10 and includes a first phosphor 41 and a second phosphor 42. Here, the first phosphor 41 and the second phosphor 42 are mixed with a translucent resin that allows light from the light source 10, light from the first phosphor 41, and light from the second phosphor 42 to pass through. Is used as the fluorescent member 40. As the resin, it is preferable to use a silicone resin composition, but an epoxy resin composition or the like can also be used. Further, other materials such as a diffusing material can be added to the fluorescent member 40.

[First Fluorescent Agent 41]
The first phosphor 41 includes a chemical vapor deposition film containing thiogallate phosphor particles having a composition represented by the following general formula (II) and aluminum oxide, and emits fluorescence in the range of green to yellowish green. As a result, the reaction between the sulfur contained in the SGS phosphor particles and the moisture and hydrogen fluoride in the atmosphere is suppressed, the moisture resistance and hydrogen fluoride resistance are improved, and the case is placed under high temperature and high humidity. However, the deterioration of the phosphor can be suppressed.
(M1 _1-x M2 _x ) Ga _2-y S _4-z (II)
(In formula (II), M1 is at least one element selected from the group consisting of Sr, Be, Mg, Ca, Ba and Zn, and M2 is at least selected from the group consisting of Eu and Ce. It is one kind of element, and x, y, and z satisfy 0.03 ≦ x ≦ 0.25, −0.2 ≦ y ≦ 0.2, and −0.2 ≦ z ≦ 0.2).

If the thiogallate phosphor particles having the composition represented by the general formula (II) emit fluorescence in the range of green to yellowish green, a part of Ga in the composition represented by the general formula (II) is Al and It may be substituted with at least one element selected from the group consisting of In, and a part of S may be substituted with at least one element selected from the group consisting of Se and Te. Further, in the thiogallate phosphor particles having the composition represented by the general formula (II), it is preferable that M1 is Sr and M2 is Eu in the formula (II), and the fluorescence in the range of green to yellowish green is exhibited. Eu may be replaced with Ce by at least one element selected from the group consisting of Be, Mg, Ca, Ba and Zn as long as it is emitted.

[Second phosphor 42]
As the second phosphor 42, a fluoride phosphor activated with manganese that emits fluorescence in the range of yellow-red to red is used. As the manganese-activated fluoride phosphor, it is preferable to use one having a composition represented by the following general formula (III). A fluoride phosphor having a composition represented by the following general formula (III) emits fluorescence having a main emission peak wavelength in the vicinity of 630 nm when excited by light from the light source.
A ₂ [M3 _1-u Mn ^{4 +} _u F ₆ ] (III)
(In the formula, ^{A, K +, Li +, Na} +, Rb +, a further include optionally cations of at least one selected from Cs ⁺ and the group consisting of _NH ^{4 +,} M3 is a Group 4 element and It is at least one element selected from the group consisting of Group 14 elements, and u indicates a number satisfying 0 <u <0.2).
Since the phosphor represented by the general formula (III) has a narrow half-value width of the main emission peak, the color reproduction range is wider than that of other red phosphors.

(Production Example 1: Preparation of thiogallate phosphor particles)
_{SrCO 3} (manufactured by Sakai Kogyo Co., Ltd.) _{as the Sr source, Eu 2} O ₄ (manufactured by Shin-Etsu Chemical Co., Ltd.) as the Eu source, so as to have the composition shown by Sr _0.88 Eu _0.12 Ga ₂ S _{4. Ga 2} O ₃ (manufactured by New Material Co., Ltd.) was weighed as a Ga source and mixed using a super mixer (manufactured by Kawata Co., Ltd.) to obtain a raw material mixture. The obtained raw material mixture was filled in a quartz crucible, and fired for two hours at 960 ° C. under hydrogen sulfide _(H 2 S) _atmosphere, composition represented by Sr _{0.88 Eu} 0.12 _Ga 2 _{S 4} The thiogallate phosphor particles having the above were obtained. The emission peak wavelength of the thiogallate phosphor particles was 537 nm. The obtained thiogallate phosphor particles were obtained by the Fisher Sub-Sieve Sizer Model 95 (manufactured by Fisher Scientific) by the Fisher Sub-Sieve Sizer (FSS) method. The average particle size measured as (FSSSN) was 6.0 μm.

( Reference example 1)
(Step of obtaining the first phosphor 41)
50 g of the thiogallate phosphor particles obtained in Production Example 1 was put into the reaction tube of the fluidized bed CVD apparatus for powder. Nitrogen gas was bubbled into trimethylaluminum (TMA) at a flow rate of 0.05 L / min, and the obtained nitrogen gas containing TMA flowed in as it was from the lower part of the reaction tube. _{Oxygen (O 2} ) flowed into the reaction tube from the upper part of the reaction tube at a flow rate of 0.15 L / min. The flow rates of TMA / N ₂ and O ₂ are both flow rates at 25 ° C. The reaction was carried out at a reaction tube temperature of 380 ° C. for 15 minutes, and oxidation treatment with trimethylaluminum was carried out to obtain a first phosphor 41 coated with a CVD film containing aluminum oxide.

(Process to obtain light emitting device)
The process of obtaining the light emitting device will be described with reference to FIG.
An LED chip made of a nitride semiconductor having an emission peak wavelength of 455 nm was arranged as the light source 10 on the bottom surface of the recess of the package 20, and the light source 10 and the first lead 21 and the second lead 22 were connected by wires 30, respectively. _{With the first phosphor 41 prepared above and K 2} SiF ₆ : Mn prepared in advance so that the CIE chromaticity coordinates x of the mixed color light emitted by the light emitting device are around 0.280 and y is around 0.270. A certain second phosphor 42 was added to the silicone resin and mixed and dispersed to obtain a phosphor-containing resin composition. An appropriate amount of this phosphor-containing resin composition was injected into the recess of the package 20, and the resin in the fluorescent composition was cured to form a fluorescent member 40 to obtain a light emitting device 100.

(Comparative Example 1)
A light emitting device was obtained in the same manner as in Reference Example 1 except that the thiogallate phosphor particles obtained in Production Example 1 were used instead of the first phosphor 41.

(Comparative Example 2)
Adhesions containing aluminum oxide were attached to the thiogallate phosphor particles obtained in Production Example 1 by the sol-gel method. Specifically, 50 g of the thiogallate phosphor particles obtained in Production Example 1 was added to 200 mL of ethanol and suspended, and 10.0 g of pure water and aluminum isopropoxide (Al (OCH (CH ₃ )) were added thereto. ₂ ) ₃ ) 5.0 g was added, and 12.2 g of aqueous ammonia (concentration 18% by mass) was further added as a catalyst to hydrolyze the aluminum alkoxide, and a phosphor to which the deposit containing aluminum oxide was attached was obtained. Obtained. A light emitting device was obtained in the same manner as in Reference Example 1 except that this phosphor was used in place of the first phosphor 41.

(Comparative Example 3)
Adhesions containing silicon dioxide were attached to the thiogallate phosphor particles obtained in Production Example 1 by the sol-gel method. Specifically, 50 g of the thiogallate phosphor particles obtained in Production Example 1 was added to 200 mL of ethanol and suspended, and 17.9 g of pure water and tetraethyl orthosilicate (TEOS: Si (OC ₂ H _{5)) were added thereto. 4} ) 17.9 g was added, and 21.4 g of aqueous ammonia (concentration 18% by mass) was further added as a catalyst to hydrolyze the silicon alkoxide to obtain a phosphor to which deposits containing silicon dioxide were attached. .. A light emitting device was obtained in the same manner as in Reference Example 1 except that this phosphor was used in place of the first phosphor 41.

( Reference example 2)
In the step of obtaining the first fluorescent material 41, the first fluorescent material 41 was obtained in the same manner as in Reference Example 1 except that the reaction was carried out in the reaction tube of the fluidized bed CVD apparatus for powder for 33 minutes. A light emitting device was obtained in the same manner as in Reference Example 1 except that 41 was used.

( Reference example 3)
In the step of obtaining the first fluorescent material 41, the first fluorescent material 41 was obtained in the same manner as in Reference Example 1 except that the reaction was carried out in the reaction tube of the fluidized bed CVD apparatus for powder for 1 hour and 41 minutes. A light emitting device was obtained in the same manner as in Reference Example 1 except that the phosphor 41 was used.

( Reference example 4)
In the step of obtaining the first fluorescent material 41, the first fluorescent material 41 was obtained in the same manner as in Reference Example 1 except that the reaction was carried out in the reaction tube of the fluidized bed CVD apparatus for powder for 3 hours and 6 minutes. A light emitting device was obtained in the same manner as in Reference Example 1 except that the phosphor 41 was used.

( Reference example 5)
In the step of obtaining the first phosphor 41, the first fluorescent material 41 was obtained in the same manner as in Reference Example 1 except that the reaction was carried out in the reaction tube of the fluidized bed CVD apparatus for powder for 3 hours and 56 minutes. A light emitting device was obtained in the same manner as in Reference Example 1 except that the phosphor 41 was used.

( Reference example 6)
In the step of obtaining the first fluorescent material 41, the first fluorescent material 41 was obtained in the same manner as in Reference Example 1 except that the reaction was carried out in the reaction tube of the fluidized bed CVD apparatus for powder for 4 hours and 16 minutes. A light emitting device was obtained in the same manner as in Reference Example 1 except that the phosphor 41 was used.

( Reference example 7)
In the step of obtaining the first fluorescent material 41, the first fluorescent material 41 was obtained in the same manner as in Reference Example 1 except that the reaction was carried out in the reaction tube of the fluidized bed CVD apparatus for powder for 5 hours and 10 minutes. A light emitting device was obtained in the same manner as in Reference Example 1 except that the phosphor 41 was used.

( Reference example 8)
Using a phosphor in which a film containing aluminum oxide is formed on the surface of the thiogallate phosphor particles obtained in Reference Example 4 by the CVD method, silicon dioxide is contained on the film containing aluminum oxide by the sol-gel method. The kimono was attached. Specifically, by adding a phosphor 50g obtained in Reference Example 4 in ethanol 200 mL, it was suspended, to which purified water 5.2 g, tetraethyl orthosilicate _{(TEOS: Si (OC 2 H} 5) 4 ) 5.2 g was added, and 6.2 g of aqueous ammonia (concentration 18% by mass) was further added as a catalyst to hydrolyze the silicon alkoxide to obtain the first phosphor 41 to which the deposit containing silicon dioxide was attached. rice field. A light emitting device was obtained in the same manner as in Reference Example 1 except that the first phosphor 41 was used.

(Example 9)
Pure water 12.3 g, tetraethyl orthosilicate _{(TEOS: Si (OC 2 H} 5) 4) 12.3g was added further aqueous ammonia as a catalyst (concentration 18 mass%) 14.6 g was added to hydrolyze the silicon alkoxide A first phosphor 41 was obtained in the same manner as in Reference Example 8 except that it was decomposed and an deposit containing silicon dioxide was attached, and the same as Reference Example 1 except that the first phosphor 41 was used. A light emitting device was obtained in the same manner.

(Example 10)
Pure water 17.9 g, tetraethyl orthosilicate _{(TEOS: Si (OC 2 H} 5) 4) 17.9g was added further aqueous ammonia as a catalyst (concentration 18 mass%) 21.4 g was added to hydrolyze the silicon alkoxide A first phosphor 41 was obtained in the same manner as in Reference Example 8 except that it was decomposed and an deposit containing silicon dioxide was attached, and the same as Reference Example 1 except that the first phosphor 41 was used. A light emitting device was obtained in the same manner.

(Example 11)
Pure water 35.7 g, tetraethyl orthosilicate _{(TEOS: Si (OC 2 H} 5) 4) 35.7g was added further aqueous ammonia as a catalyst (concentration 18 mass%) 42.9 g was added to hydrolyze the silicon alkoxide A first phosphor 41 was obtained in the same manner as in Reference Example 8 except that it was decomposed and an deposit containing silicon dioxide was attached, and the same as Reference Example 1 except that the first phosphor 41 was used. A light emitting device was obtained in the same manner.

( Reference example 12)
Pure water 65.0 g, tetraethyl orthosilicate _{(TEOS: Si (OC 2 H} 5) 4) 65.0g was added further aqueous ammonia as a catalyst (concentration 18 mass%) 78.0 g was added to hydrolyze the silicon alkoxide A first phosphor 41 was obtained in the same manner as in Reference Example 8 except that it was decomposed and an deposit containing silicon dioxide was attached, and the same as Reference Example 1 except that the first phosphor 41 was used. A light emitting device was obtained in the same manner.

( Reference example 13)
50 g of the phosphor particles obtained in Comparative Example 3 was charged into the reaction tube of the fluidized layer CVD apparatus for powder and reacted for 2 hours and 36 minutes, and the thiogallate phosphor particles were formed in the same manner as in Example 1. A first phosphor 41 in which a deposit containing silicon dioxide was attached and a film containing aluminum oxide was formed on the surface of the deposit containing silicon dioxide was obtained by a CVD method. A light emitting device was obtained in the same manner as in Reference Example 1 except that the first phosphor 41 was used.

[Evaluation of the first phosphor 41]
The first fluorescent material 41 obtained in Reference Examples 1 to 7 , 8, 12, and 13 and Examples 9 to 11 and the fluorescent material replacing the first fluorescent material 41 of Comparative Examples 1 to 3 were averaged by the following method. The particle size, the content of the aluminum element and the content of the silicon element were measured.

(Average particle size)
The average particle size of the phosphor is determined by the Fisher Sub-Sieve Sizer Model 95 (manufactured by Fisher Scientific) by the Fisher Sub-Sieve Sizer (FSSS) method. The average particle size was measured as FSSSSN).

(Aluminum element content)
The masses of the aluminum elements contained in the first phosphors 41 and the phosphors of Comparative Examples 2 obtained in Reference Examples 1 to 7 , 8, 12, and 13 and Examples 9 to 11 were measured by an ICP analyzer (Hitachi High-Tech Science). The content of the aluminum element was calculated by the following formula by measuring using SPS3500) manufactured by the company.
Content of aluminum element in phosphor (mass%) = mass of aluminum element (g) ÷ total mass of phosphor (g) x 100

(Content of silicon element)
The mass of the silicon element contained in the first phosphor 41 and the phosphor of Comparative Example 3 obtained in Examples 9 to 11 , Reference Examples 8, 12, and 13 was measured by an ICP analyzer (manufactured by Hitachi High-Tech Science Co., Ltd., SPS3500). ), And the content of silicon element was calculated by the following formula.
Content of silicon element in phosphor (mass%) = mass of silicon element (g) ÷ total mass of phosphor (g) × 100

(SEM image)
Using a scanning electron microscope (SEM), SEM images of the first phosphor 41 and the phosphor of Comparative Example 2 obtained in Reference Example 3 and Example 10 and an SEM image of a cross section were obtained. Figure 2 is an SEM image of a first fluorescent material 41 of Reference Example 3, FIG. 3 is a cross-sectional SEM image of the first phosphor 41 of Example 3. FIG. 4 is an SEM image of the phosphor of Comparative Example 2, and FIG. 5 is an SEM image of a cross section of the phosphor of Comparative Example 2. FIG. 8 is an SEM image of the first phosphor 41 of Example 10, and FIG. 9 is an SEM image of a cross section of the first phosphor 41 of Example 10.

(Average value of the ratio of the thickness of the film containing aluminum oxide to the particle size of the first phosphor)
The average value of the ratio of the thickness of the film containing aluminum oxide to the particle size of the first phosphor 41 in Reference Examples 1 to 7 was obtained by photographing the cross section of the obtained first phosphor 41 with a scanning electron microscope (SEM). , The sum of the particle size (major axis) of the core thiogallate phosphor particles and the thickness of the film containing aluminum oxide was measured, and it was calculated from this measured value by the following formula (1).
Ratio of film thickness to particle size (%)
= Sum of film thickness ÷ (sum of core particle major axis + film thickness) x 100 (1)
The ratio of the film thickness to the particle size was determined for the three phosphor particles, and the average value of the film thickness ratio was calculated as the arithmetic mean. The sum of the thicknesses of the films containing aluminum oxide was measured from the difference in contrast between the core thiogallate phosphor particles in the SEM image and the film containing aluminum oxide.

(Average value of the ratio of the thickness of the deposit containing silicon dioxide to the particle size of the phosphor)
In the phosphor of Comparative Example 3, the average value of the ratio of the thickness of the deposit containing silicon dioxide to the particle size of the first phosphor 41 was obtained by scanning the cross section of the first phosphor 41 with a scanning electron microscope (SEM). The sum of the particle size (major axis) of the core thiogallate phosphor particles and the thickness of the deposit containing silicon dioxide was measured, and calculated from this measured value by the following formula (2).
Ratio of deposit thickness to particle size (%)
= Sum of thickness of deposits ÷ (sum of major axis of core particles + sum of thickness of deposits) x 100 (2)
The ratio of the thickness of the deposit to the particle size was determined for the three phosphor particles, and the average value of the ratio of the thickness of the deposit was calculated as the arithmetic mean. The sum of the thicknesses of the films containing aluminum oxide was measured from the difference in contrast between the core thiogallate phosphor particles in the SEM image and the deposits containing silicon dioxide.

(Average value of the ratio of the thickness of the deposit containing silicon dioxide to the particle size of the first phosphor)
In the first phosphor 41 obtained in Examples 9 to 11 and Reference Examples 8 and 12, the film containing aluminum oxide and the deposit containing silicon dioxide cannot be distinguished from each other from the difference in contrast in the SEM image. Can not. Therefore, similarly to Reference Examples 1 to 7, the thickness of the film containing aluminum oxide formed in contact with the surface of the thiogallate phosphor particles is measured first, and then the surface of the film containing aluminum oxide contains silicon dioxide. After the kimono is formed, the total thickness of the film containing aluminum oxide and the deposit containing silicon dioxide is measured, and the thickness of the previously formed film containing aluminum oxide is subtracted from this total thickness to obtain carbon dioxide. The thickness of the deposit containing silicon was calculated. The ratio (%) of the thickness of the deposit to the particle size was calculated by using the calculated value of the thickness of the obtained deposit containing silicon dioxide as the sum of the thickness of the deposit of the above formula (2).
The ratio of the thickness of the deposit to the particle size was determined for the three phosphor particles, and the average value of the ratio of the thickness of the deposit was calculated as the arithmetic mean.

In the first phosphor 41 obtained in Reference Example 13, the deposit containing silicon dioxide and the film containing aluminum oxide cannot be distinguished from each other from the difference in contrast in the SEM image.
When a deposit containing silicon dioxide is formed in contact with the surface of the thiogallate phosphor particles, the deposit containing silicon dioxide formed in contact with the surface of the thiogallate phosphor particles is formed in the same manner as in Comparative Example 3. The thickness is measured first, and then the film containing aluminum oxide is formed in contact with the surface of the deposit containing silicon dioxide, and then the total thickness of the film containing aluminum oxide and the deposit containing silicon dioxide is measured. The thickness of the film containing aluminum oxide was calculated by subtracting the thickness of the previously formed deposit containing silicon dioxide from this thickness.
The ratio (%) of the thickness of the deposit to the particle size was calculated by using the calculated value of the thickness of the obtained film containing aluminum oxide as the sum of the thickness of the film of the above formula (1).
The ratio of the thickness of the film to the particle size was determined for the three phosphor particles, and the average value of the ratio of the thickness of the deposits was calculated as the arithmetic mean.

(Elemental analysis by SEM-EDX method)
Using SEM-EDX (scanning electron microscope / energy dispersive X-ray spectroscopy), elemental analysis of the regions marked with x in the SEM images of each phosphor shown in FIGS. 3, 5 and 9 was performed.
FIG. 6 shows the results of elemental analysis by the SEM-EDX method in the regions marked with x in the SEM image of the first phosphor 41 of Reference Example 3 shown in FIG. 3 (horizontal axis: energy (keV), vertical axis: count). It is a figure which shows the number).
FIG. 7 shows the results of elemental analysis by the SEM-EDX method in the regions marked with x in the SEM image of the phosphor used in Comparative Example 2 shown in FIG. 5 (horizontal axis: energy (keV), vertical axis: count number). ).
FIG. 10 shows the results of elemental analysis by the SEM-EDX method in the regions marked with x in the SEM image of the first phosphor 41 used in Example 10 shown in FIG. 9 (horizontal axis: energy (keV), vertical axis). : Count number).

[Evaluation of light emitting device]
For the light emitting devices of Reference Examples 1 to 7, 8, 12, 13, and Examples 9 to 11 and Comparative Examples 1 to 3, the initial relative luminous flux and the reliability evaluation test of the following light emitting devices were performed.

(Initial value relative luminous flux)
Luminous flux was measured using a total luminous flux measuring device using an integrating sphere for the light emitting devices of Reference Examples 1 to 7, 8, 12, 13 and Examples 9 to 11 and Comparative Examples 1 to 3 before storage. The initial relative luminous flux was calculated with reference to the luminous flux of the light emitting device of Comparative Example 1.

(LED reliability evaluation: difference Δy between CIE chromaticity coordinates y values before and after storage)
The light emitting device was stored in a high-temperature and high-humidity environmental tester at 60 ° C. and 90% relative humidity at a current of 20 mA with or without continuous lighting for 1000 hours. The y1 value in the CIE chromaticity coordinates before storage and the y2 value in the CIE chromaticity coordinates after storage were measured using a multi-channel spectroscope (Hamamatsu Photonics Co., Ltd., product name: PMA = 12), and the y1 value was obtained. The difference Δy of the y2 values was calculated as an absolute value.

(LED reliability evaluation: relative luminous flux (Po) after storage)
The light emitting device was stored in a high-temperature and high-humidity environmental tester at 60 ° C. and 90% relative humidity at a current of 20 mA with or without continuous lighting for 1000 hours. With the total luminous flux measuring device using the integrating sphere, the luminous flux of the light emitting device after storage was determined as the relative luminous flux (Po) when the initial value of the light emitting device before storage was set to 100.

Table 1 shows the evaluation results of the phosphors used in Comparative Examples 1 to 3 and the first phosphor 41 used in Reference Examples 1 to 7 and a light emitting device using these phosphors.

As shown in Table 1, the light emitting devices of Reference Examples 1 to 7 have an absolute value of difference Δy as compared with the light emitting device of Comparative Example 1 even after being continuously lit for 1000 hours under high temperature and high humidity and stored. Was small, and it was confirmed that there was no chromaticity shift. Further, as shown in Table 1, the light emitting devices of Reference Examples 1 to 7 are relative to the light emitting devices of Comparative Examples 1 to 3 even after being continuously lit for 1000 hours under high temperature and high humidity and stored. It was confirmed that the luminous flux (Po) was maintained at 90 or more, the light emission output was maintained as compared with that before storage, and the decrease in the light emission output was suppressed.
The first phosphor 41 used in the light emitting devices of Reference Examples 1 to 7 has an average value of 0.5% of the ratio of the thickness of the film containing aluminum oxide formed by the CVD method to the particle size of the first phosphor 41. It has been confirmed that the moisture resistance and hydrogen fluoride resistance are improved by using the first phosphor 41 in which a film containing aluminum oxide having an average value of this ratio is formed, which is 10.0% or more or more. did it.
On the other hand, as shown in Table 1, Comparative Example 1 in which thiogallate phosphor particles having not formed a film containing aluminum oxide by the CVD method were used instead of the first phosphor 41, and aluminum oxide formed by the sol-gel method. In the light emitting device of Comparative Example 2 in which a phosphor having a deposit containing the above substance was used instead of the first phosphor 41, the difference Δy was 0. It was as large as 08 or more, a chromaticity shift occurred, the relative light beam (Po) was as low as 85 or less, and the emission output was lowered.
The phosphor provided with the aluminum oxide-containing deposits formed by the sol-gel method of Comparative Example 2 had substantially uniform thickness and no aluminum oxide-containing deposits adhered to the surface of the thiogallate phosphor particles, and the surface was uneven. Was formed.
The light emitting device using the phosphor provided with the deposit containing silicon dioxide formed by the sol-gel method of Comparative Example 3 has a low relative luminous flux of less than 90 after being continuously lit for 1000 hours under high temperature and high humidity. The light emission output was reduced.

As shown in FIGS. 2 and 3, in the first phosphor 41 used in Reference Example 3, a smooth film containing aluminum oxide was formed on the entire surface of the thiogallate phosphor particles by the CVD method.
On the other hand, as shown in FIGS. 4 and 5, in the phosphor used in place of the first phosphor 41 of Comparative Example 2, deposits containing aluminum oxide by the sol-gel method were formed on a part of the surface of the thiogallate phosphor particles. It was attached. In addition, these deposits were in a state in which the generated small aluminum oxide particles were agglomerated with each other. As shown in FIG. 4, the surface of the phosphor used in place of the first phosphor 41 of Comparative Example 2 is uneven because the surface of the thiogallate phosphor particles is not slippery due to the deposit containing aluminum oxide by the sol-gel method. Was.

As shown in FIG. 6, in the SEM image of the first phosphor 41 used in Reference Example 3 shown in FIG. 3, the element by the SEM-EDX method in which the region of the substantially central portion in the thickness direction of the film containing aluminum oxide was measured. As a result of the analysis, in addition to the carbon element (C) derived from the sample preparation and the elements constituting the thiogallate phosphor particles, strontium (Sr), gallium (Ga), and sulfur (S), aluminum (Al) And the peak of the oxygen (O) element appears, and the first phosphor 41 used in Reference Example 3 is in contact with the surface of the thiogallate phosphor particles, and a film containing aluminum oxide is formed by the CVD method. It could be confirmed.

As shown in FIG. 7, in the SEM image of the phosphor used in Comparative Example 2 shown in FIG. 5, elemental analysis by the SEM-EDX method was performed by measuring the region near the surface of the deposit containing aluminum oxide formed by the solgel method. As a result, it is formed by the solgel method in addition to the carbon element (C) derived from the sample preparation and the elements constituting the thiogallate phosphor particles, strontium (Sr), gallium (Ga), and sulfur (S). Peaks of aluminum (Al) and oxygen (O) elements, which constitute deposits containing aluminum oxide, appeared.

Table 2 shows the evaluation results of the fluorescent substances used in Comparative Examples 1 to 3 and the first fluorescent substances 41 used in Examples 9 to 11, Reference Examples 8 , 12 and 13, and the light emitting device using these fluorescent substances. Is shown.

As shown in Table 2, the light emitting devices of Examples 9 to 11 and Reference Examples 8 , 12, and 13 were stored under high temperature and high humidity under continuous lighting for 1000 hours, but after being stored without lighting for 1000 hours. Also, it was confirmed that the absolute value of the difference Δy was smaller than that of the light emitting devices of Comparative Examples 1 to 3 and that the chromaticity deviation did not occur. Further, as shown in Table 2, the light emitting devices of Examples 9 to 11 and Reference Examples 8 , 12, and 13 were continuously lit for 1000 hours under high temperature and high humidity, and were not lit for 1000 hours even after being stored. Even after storage, the relative luminous flux (Po) was maintained at 80 or more. Compared with the light emitting devices of Comparative Examples 1 to 3, the light emitting devices of Examples 9 to 11 and Reference Examples 8 , 12, and 13 maintained the light emitting output even after being stored under high temperature and high humidity for 1000 hours, and the light emitting output was maintained. It was confirmed that the decrease in the amount was suppressed.
When the amount of deposits containing silicon dioxide is small as in the first phosphor 41 used in Reference Example 8, the relative luminous flux becomes different in Example 9 after storage under high temperature and high humidity for 1000 hours without lighting. ~ 11, It was lower than Reference Examples 12 and 13.
Further, like the first phosphor 41 used in Reference Example 13, after deposits containing silicon dioxide are attached to the surface of the thiogallate phosphor particles by the sol-gel method, deposits containing thiogallate phosphor particles and silicon dioxide are attached. Even when a film containing aluminum oxide is formed from above by the CVD method, the chromaticity is maintained under high temperature and high humidity under continuous lighting for 1000 hours, and after storage without lighting for 1000 hours. It was confirmed that the deviation can be suppressed, the relative light beam can be maintained, and the decrease in the emission output can be suppressed.

As shown in FIG. 8, in the first phosphor 41 used in Example 10, a film containing smooth aluminum oxide formed by the CVD method was formed on the entire surface of the thiogallate phosphor particles, and aluminum oxide was further formed. Adhesions containing silicon dioxide were adhered to the surface of the containing film relatively smoothly. As shown in FIG. 9, in the first phosphor 41 used in Example 10, a film containing aluminum oxide and a deposit containing silicon dioxide formed on the entire surface of the thiogallate phosphor particles by the CVD method were uniformly formed. It was formed with a similar thickness.

As shown in FIG. 10, in the SEM image of the first phosphor 41 used in Example 10 shown in FIG. 9, the regions of the film containing aluminum oxide and the deposit containing silicon dioxide formed by the CVD method were measured. As a result of elemental analysis by the SEM-EDX method, carbon element (C) derived during sample preparation, strontium (Sr), gallium (Ga), sulfur (S) elements, which are elements constituting thiogallate phosphor particles, and others The peaks of the aluminum (Al) and oxygen (O) elements that make up the film containing aluminum oxide appear, and the peaks of the silicon (Si) and oxygen (O) elements that make up the deposit containing silicon dioxide appear. It was confirmed that the first phosphor 41 used in Example 10 had a film containing aluminum oxide and an deposit containing silicon dioxide formed on the surface of the thiogallate phosphor particles.

The light emitting device according to the present invention can be suitably used for a white LED display light source, a backlight light source, a lighting light source, and the like.

10: Light source, 20: Package, 21: First lead, 22: Second lead, 23: Molded product, 30: Wire, 40: Fluorescent member, 41: First fluorescent material, 42: Second fluorescent material, 100: Light source

Claims (9)

The particles made of the thiogallate phosphor are brought into contact with the surface of the particles of the thiogalate phosphor, and a film containing aluminum oxide is formed on the entire surface of the particles of the thiogalate phosphor by a CVD method to contain the aluminum oxide. A step of forming an deposit containing silicon dioxide on the surface of the film to obtain a first phosphor that emits fluorescence in the range of green to yellow-green, and a light source that emits light having an emission peak wavelength in the range of 420 to 480 nm. The CIE chromaticity coordinate x is 0.280, using the first phosphor and the second phosphor which is a fluoride phosphor activated with manganese that emits fluorescence in the yellow-red to red range. Including a step of obtaining a light emitting device that emits mixed color light having y of 0.270.
The average value of the ratio of the thickness of the film containing aluminum oxide to the particle size of the first phosphor is 0.5% or more and 10% or less.
The average value of the ratio of the thickness of the deposit containing silicon dioxide to the particle size of the first phosphor is 1.7% to 5.1%.
A method for manufacturing a light emitting device, wherein the content of the aluminum element in the first phosphor is 0.2% by mass or more and 10% by mass or less. The particles made of the thiogallate phosphor are brought into contact with the surface of the particles of the thiogalate phosphor, and a film containing aluminum oxide is formed on the entire surface of the particles of the thiogalate phosphor by a CVD method to contain the aluminum oxide. A step of forming an deposit containing silicon dioxide on the surface of the film to obtain a first phosphor that emits fluorescence in the range of green to yellow-green, and a light source that emits light having an emission peak wavelength in the range of 420 to 480 nm. The CIE chromaticity coordinate x is 0.280, using the first phosphor and the second phosphor which is a fluoride phosphor activated with manganese that emits fluorescence in the yellow-red to red range. Including a step of obtaining a light emitting device that emits mixed color light having y of 0.270.
The average value of the ratio of the thickness of the film containing aluminum oxide to the particle size of the first phosphor is 0.5% or more and 10% or less.
The average value of the ratio of the thickness of the deposit containing silicon dioxide to the particle size of the first phosphor is 1.7% to 5.1%.
A method for manufacturing a light emitting device, wherein the average particle size of the first phosphor is 3.0 μm or more and 20 μm or less. The method for manufacturing a light emitting device according to claim 1 or 2 , wherein the deposit containing silicon dioxide is formed by a sol-gel method. The method for manufacturing a light emitting device according to claim 2, wherein the content of the aluminum element in the first phosphor is 0.2% by mass or more and 10% by mass or less. The method for manufacturing a light emitting device according to any one of claims 1 to 4, wherein the content of the aluminum element in the first phosphor is 0.4% by mass or more and 10% by mass or less. The method for manufacturing a light emitting device according to any one of claims 1 to 5, wherein the content of the silicon element in the first phosphor is 0.5% by mass or more and 10% by mass or less. The method for manufacturing a light emitting device according to any one of claims 1 to 6, wherein the content of the silicon element in the first phosphor is 1.7% by mass or more and 5.0% by mass or less. The light emission according to any one of claims 1 to 7, wherein the average value of the ratio of the thickness of the film containing aluminum oxide to the particle size of the first phosphor is 0.7% or more and 8.0% or less. Manufacturing method of the device. The method for manufacturing a light emitting device according to claim 1, wherein the average particle size of the first phosphor is 3.0 μm or more and 20 μm or less.

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