JP7522344B2 - Manufacturing method of molded body, molded body and light emitting device - Google Patents

Description

The present invention relates to a method for manufacturing a molded body, a molded body, and a light-emitting device.

Light-emitting devices that combine light-emitting elements such as light-emitting diodes (LEDs) and semiconductor laser (LD) chips with phosphors are used as illumination, backlights for liquid crystal display devices, car lights, light sources for projectors, etc. Light-emitting devices are required to be compact depending on the application and location to which they are applied. In addition, for example, in a projector light source that uses an LD as a light-emitting element, high-energy light is emitted locally from the light-emitting element, so the member containing the phosphor that converts the wavelength by the light emitted from the light-emitting element is required to have high heat resistance.

For example, Patent Document 1 discloses a wavelength conversion member that is made of an inorganic material such as glass or sapphire with good thermal conductivity, and that has a phosphor layer made of phosphor and translucent ceramics on a light-transmitting substrate.

International Publication No. 2017/126440

One aspect of the present invention aims to provide a method for producing a molded body having excellent color rendering properties and heat resistance, and a molded body and a light-emitting device.

The present invention includes the following aspects.
A first aspect of the present invention is a method for manufacturing a molded body, comprising: preparing a light-transmitting substrate made of an inorganic material containing first phosphor particles, and a first mixed liquid obtained by mixing second phosphor particles and an alkali metal silicate aqueous solution; disposing the substrate in an electrolyte solution containing cations; pouring the first mixed liquid into the electrolyte solution to prepare a second mixed liquid, causing the second phosphor particles to settle on the substrate; removing a supernatant liquid from the second mixed liquid; and heat-treating the substrate and the second phosphor particles disposed on the substrate in a temperature range of 60°C or higher and 400°C or lower to fix the second phosphor particles on the substrate.

The second aspect of the present invention is a molded body including a base made of an inorganic material containing first phosphor particles, second phosphor particles arranged on the base, a coating of silicon dioxide containing an alkali metal that fixes the second phosphor particles to the base, and a light-transmitting protective film of oxide or nitride having a thickness of 10 nm to 1 μm formed on the coating, and the surface of the molded body has irregularities caused by the second phosphor particles.

A third aspect of the present invention is a light-emitting device comprising the molded body and a light source that irradiates the molded body.

According to one aspect of the present invention, it is possible to provide a manufacturing method for a molded body having excellent color rendering properties and heat resistance, and a molded body and a light-emitting device.

1 is a flowchart illustrating an example of a manufacturing method. 1 is a flowchart illustrating an example of a manufacturing method. FIG. 2 is a schematic cross-sectional view showing a molded body according to the first embodiment. FIG. 5 is a schematic cross-sectional view showing a molded body according to a second embodiment. FIG. 11 is a schematic cross-sectional view showing a molded body according to a third embodiment. FIG. 1 is a schematic perspective view showing a light-emitting module, which is an example of a light-emitting device. 1 is a schematic plan view showing a light-emitting module which is an example of a light-emitting device. 6C is a cross-sectional view taken along line VIC-VIC in FIG. 6B. 6C is a cross-sectional view taken along line VID-VID in FIG. 6B. FIG. 1 is a schematic cross-sectional view showing a light-emitting device including a molded body as a light-transmitting member. FIG. 2 is a schematic bottom view of the light emitting device. FIG. 1 is a schematic side view showing an overview of a light source device for a projector. 8 is a schematic plan view showing one surface of the phosphor wheel as viewed from the arrow A in FIG. 7 . 9 is a schematic plan view showing one surface of the phosphor wheel as viewed from the arrow B in FIG. 8 . 9 is a schematic plan view showing one surface of the phosphor wheel as viewed from the arrow C in FIG. 8 . FIG. 1 is a schematic diagram illustrating a configuration of a projector equipped with a light source device. FIG. 2 is a schematic front view of the lighting device. FIG. 2 is a schematic cross-sectional view of a lighting device. 4 is a SEM photograph showing a cross section of a substrate and an end face of a second phosphor particle fixed with a silicon dioxide coating according to Example 1. 4 is a photograph showing the appearance of a plane of a molded body in which second phosphor particles are fixed to the surface of a base according to Example 1. FIG. 2 is a diagram showing SEM-EDS spectra of a cross section of a substrate and a surface of second phosphor particles fixed with silicon dioxide in Example 1. 1 is an SEM photograph showing a cross section of a substrate and an end face of a second phosphor particle fixed with silicon dioxide according to Example 1, in which an SEM-EDS spectrum was measured and an SEM-EDS mapping was created. FIG. 2 is a SEM-EDS element mapping diagram showing locations where oxygen (O) is present in SEM photographs of a cross section of a substrate and an end face of a second phosphor particle fixed with silicon dioxide according to Example 1. FIG. 2 is a SEM-EDS element mapping diagram showing locations where aluminum (Al) is present in SEM photographs of a cross section of a substrate and an end face of a second phosphor particle fixed with silicon dioxide according to Example 1. FIG. 2 is a SEM-EDS element mapping diagram showing locations where silicon (Si) is present in SEM photographs of a cross section of a substrate and an end face of a second phosphor particle fixed with silicon dioxide according to Example 1. FIG. 2 is a SEM-EDS element mapping diagram showing locations where potassium (K) is present in SEM photographs of a cross section of a substrate and an end face of a second phosphor particle fixed with silicon dioxide according to Example 1.

The manufacturing method of the molded body, the molded body, and the light-emitting device according to the present invention will be described below based on one embodiment. However, the embodiment shown below is an example for embodying the technical idea of the present invention, and the present invention is not limited to the manufacturing method of the molded body, the molded body, and the light-emitting device shown below. The relationship between the color name and the chromaticity coordinates follows JIS Z8110.

The above-mentioned Patent Document 1 describes the use of glass or sapphire, which has high thermal conductivity, as the substrate. However, it does not describe the use of phosphor particles as the substrate. The phosphor layer is formed on the substrate. Patent Document 1 describes that if the thickness of the phosphor layer is excessively thin compared to the particle diameter of the phosphor particles, the light passes through without being wavelength-converted by the phosphor particles, and the performance of converting the wavelength of light is not fully exhibited. In addition, it is disclosed that depending on the particle diameter of the phosphor particles, when the particle diameter of the phosphor particles is set to 1, a thickness of the phosphor layer of 1.5 or more is required for the particle diameter of the phosphor, and depending on the particle diameter of the phosphor, the demand for thinning may not be met. Furthermore, Patent Document 1 describes that by using a substrate with high thermal conductivity, heat storage in the phosphor layer is suppressed, and when the thickness of the phosphor layer exceeds a certain number times the particle diameter of the phosphor particles, the thermal resistance of the grain boundary increases, the temperature of the phosphor layer increases, and the luminous intensity decreases. Depending on the particle diameter of the phosphor particles, it may not be possible to contain the desired phosphor in the phosphor layer, and the desired luminous color may not be obtained. In addition, in Patent Document 1, phosphor particles are mixed with an inorganic binder such as ethyl silicate, and the mixture is applied by screen printing, and the organic components are removed to adhere the phosphor layer to the substrate. When the phosphor particles and the inorganic binder are mixed, the inorganic binder adheres to the periphery of the phosphor particles, and the inorganic binder is interposed between the phosphor particles in the phosphor layer and between the phosphor particles and the substrate. In this way, when the inorganic binder is interposed between the phosphor particles and between the phosphor particles and the substrate, heat is transferred to the substrate via the inorganic binder, which has a lower thermal conductivity than the substrate, resulting in a lower thermal conductivity and reduced heat resistance.

In contrast, the manufacturing method of the molded body, the molded body, and the light-emitting device according to the present embodiment can provide a molded body having excellent color rendering and heat resistance. In other words, by using a base made of an inorganic material containing first phosphor particles, and fixing the second phosphor particles to the base with a silicon dioxide coating so as to compensate for the poor color rendering of the first phosphor particles, it is possible to improve the color rendering as a whole. In other words, the color rendering is not sufficient with a base made of an inorganic material containing first phosphor particles, and further improvement in color rendering is required, so that the color rendering can be improved by fixing the second phosphor particles to this base. In addition, when the first mixed liquid in which the second phosphor particles and an alkali metal silicate aqueous solution are mixed is poured onto a base placed in an electrolyte containing cations, the second phosphor particles are allowed to settle, and the second phosphor particles are fixed to the base with silicon dioxide, the second phosphor particles are fixed in close contact with the base, and heat is transferred directly from the second phosphor particles to the base, so that the thermal conductivity is increased and the molded body has excellent heat resistance.

Method for manufacturing a molded body The method for manufacturing a molded body includes preparing a light-transmitting base made of an inorganic material containing first phosphor particles and a first mixed liquid obtained by mixing second phosphor particles and an alkali metal silicate aqueous solution, placing the base in an electrolyte solution containing cations, pouring the first mixed liquid into the electrolyte solution to prepare a second mixed liquid and allowing the second phosphor particles to settle on the base, removing the supernatant liquid from the second mixed liquid, and heat-treating the base and the second phosphor particles placed on the base in a temperature range of 60°C or more and 400°C or less to fix the second phosphor particles on the base.

1 and 2 are flow charts showing an example of a method for manufacturing a molded body. The method for manufacturing a molded body will be described with reference to FIGS. 1 and 2. The method for manufacturing a molded body includes preparing a substrate S101a, preparing a first mixed liquid S101b, disposing the substrate in an electrolyte solution containing cations S102, pouring the first mixed liquid into the electrolyte solution to prepare a second mixed liquid S103, and allowing the second phosphor particles to settle on the substrate S103, removing the supernatant liquid from the second mixed liquid S104, and subjecting the substrate and the second phosphor particles disposed on the substrate to a heat treatment to fix the second phosphor particles on the substrate S105. The method for manufacturing a molded body may include forming a protective film by atomic deposition after fixing the second phosphor particles S106.

Preparing a base and a first mixed liquid In a method for manufacturing a molded body, a base made of an inorganic material containing first phosphor particles and a first mixed liquid in which second phosphor particles and an alkali metal silicate aqueous solution are mixed are prepared.

Preparing a base In the method for manufacturing a molded body, a base is prepared. The base is made of an inorganic material containing first phosphor particles and has translucency. The base may be made by fixing only the first phosphor particles by sintering, pressure welding, or the like. If the base is made of only the first phosphor particles, the wavelength conversion efficiency can be increased. In addition, if the base is made of only the first phosphor particles, there is no need to consider deterioration of other members or differences in linear expansion coefficient with other members. The base may contain the first phosphor particles and at least one inorganic material selected from ceramics and glass. Even if the first phosphor particles are used alone or in combination with other inorganic materials, the base is made of only inorganic materials, so it has excellent thermal conductivity and at least one of laser resistance, heat resistance, and light resistance. In this specification, translucency refers to a light transmittance of 5% or more at the emission peak wavelength of light irradiated onto the base, and the light transmittance of 10% or more at the emission peak wavelength of light irradiated onto the base is preferably 20% or more. As used herein, ceramics refers to any inorganic, non-metallic material at temperatures below 1000°C.

When the substrate contains ceramics, the ceramics are preferably at least one selected from the group consisting of aluminum oxide, aluminum nitride, mullite, and silicon nitride. If the ceramics are at least one selected from the group consisting of aluminum oxide, aluminum nitride, mullite, and silicon nitride, a substrate having translucency and excellent heat resistance can be obtained. It is more preferable that the ceramics are at least one selected from the group consisting of aluminum oxide, aluminum nitride, and silicon nitride. If the ceramics contained in the substrate is at least one selected from the group consisting of aluminum oxide, aluminum nitride, and silicon nitride, a substrate having translucency, heat resistance, and excellent thermal conductivity can be obtained.

When the substrate contains glass, the glass may be, for example, borosilicate glass. Examples of borosilicate glass include barium borosilicate glass and aluminoborosilicate glass. The glass may have a softening point of 500°C or higher, a softening point of 600°C or higher, or a softening point of 700°C or higher.

The thickness of the substrate is not particularly limited. Taking into consideration mechanical strength and wavelength conversion efficiency, the substrate preferably has a thickness in the range of 1 μm to 1 mm, may have a thickness in the range of 10 μm to 800 μm, may have a thickness in the range of 50 μm to 500 μm, or may have a thickness in the range of 100 μm to 300 μm.

First phosphor particles The first phosphor particles emit light when irradiated with light from a light source, and in order to obtain the desired chromaticity, it is preferable that the first phosphor particles are at least one type selected from the group consisting of rare earth aluminate phosphors, alkaline earth metal silicate phosphors, alkaline earth metal aluminate phosphors, alkaline earth metal halosilicate phosphors, and β-sialon phosphors.

The first phosphor particles may be phosphor particles that have a peak emission wavelength in the range of 530 nm to 590 nm when irradiated with light from a light source, or may be phosphor particles that have a peak emission wavelength in the range of 490 nm to 555 nm.

When the first phosphor particles are phosphor particles that have an emission peak wavelength in the range of 530 nm to 590 nm when irradiated with light from a light source, it is preferable that the first phosphor particles contain at least one type of aluminate phosphor.

The aluminate phosphor may be a rare earth aluminate phosphor having a composition represented by the following formula (1A).
M ¹ ₃ (Al, Ga) ₅ O ₁₂ :Ce (1A)
In formula (1A), ^M1 is at least one selected from the group consisting of Y, Lu, Gd and Tb.
In this specification, in a composition formula, a plurality of elements separated by a comma (,) means that at least one of these elements is contained in the composition. A plurality of elements separated by a comma (,) in a composition formula includes at least one element selected from the plurality of elements separated by the comma in the composition, and may include a combination of two or more of the plurality of elements. In this specification, in a formula representing the composition of a phosphor, the part before the colon (:) represents the elements constituting the host crystal and their molar ratio, and the part after the colon (:) represents an activator element.

When the first phosphor particles are phosphor particles having an emission peak wavelength in the range of 530 nm or more and 590 nm or less when irradiated with light from a light source, examples of the first phosphor particles include _Y3Al5O12 : _Ce , _Y3 (Al,Ga _{)5O12:Ce, (Y,Gd)3Al5O12:Ce, Lu3Al5O12 : Ce , and Lu3 ( Al ,} Ga _{) 5O12 :} Ce.

As described above, or instead of the above, when the first phosphor particles are phosphor particles having an emission peak wavelength in the range of 490 nm to 555 nm by light irradiated from a light source, the first phosphor particles may be at least one phosphor selected from the group consisting of alkaline earth metal silicate phosphors, alkaline earth metal aluminate phosphors, alkaline earth metal halosilicate phosphors, and β-sialon phosphors. For example, the first phosphor particles may be at least one phosphor selected from the group consisting of alkaline earth metal silicate phosphors having a composition represented by the following formula (1B), alkaline earth metal aluminate phosphors having a composition represented by the following formula (1C), alkaline earth metal halosilicate phosphors having a composition represented by the following formula (1D), and β-sialon phosphors having a composition represented by the following formula (1E).

BaSi ₂ O ₂ N ₂ :Eu (1B)
Sr ₄ Al ₁₄ O ₂₅ :Eu (1C)
(Ca, Sr, Ba) ₈ MgSi ₄ O ₁₆ (F, Cl, Br) ₂ :Eu (1D)
Si _6-a Al _a O _a N _8-a :Eu (1E)
In formula (1E), a is a number that satisfies 0<a<4.2.

When the first phosphor particles are phosphor particles having an emission peak wavelength in the range of 490 nm or more and 555 nm or less by light irradiated from a light source, specific examples of the first phosphor particles include Ca ₈ MgSi ₄ O ₁₆ Cl ₂ :Eu and the like.

The content of the first phosphor particles in the base varies depending on the desired chromaticity. As described above, the base may be one in which the first phosphor particles are sintered, and the content of the first phosphor particles in the base may be 100%. When the base contains at least one inorganic material selected from ceramics and glass that does not convert the wavelength of the irradiated light in addition to the first phosphor particles, the content of the first phosphor particles may be in the range of 0.1 mass% or more and 99.9 mass% or less with respect to the total amount of the inorganic material and the first phosphor particles constituting the base. The content of the first phosphor particles is more preferably 0.5 mass% or more, more preferably 1 mass% or more, more preferably 3 mass% or more, and particularly preferably 5 mass% or more. In addition, the content of the first phosphor particles is more preferably 95 mass% or less, more preferably 80 mass% or less, more preferably 70 mass% or less, and particularly preferably 50 mass% or less. When the base contains first phosphor particles and at least one inorganic material selected from ceramics and glass that does not convert the wavelength of the irradiated light, if the content of the first phosphor particles is within the range of 0.1 mass% to 99.9 mass% relative to the total amount of the first phosphor particles and the inorganic material, the base containing the first phosphor particles and the second phosphor particles containing particles that exist intermittently in the horizontal direction along the surface of the base can convert the wavelength of the irradiated light to obtain mixed color light with the desired chromaticity.

The average particle size of the first phosphor particles is preferably in the range of 1 μm or more and 50 μm or less. The average particle size of the first phosphor particles is more preferably 2 μm or more, more preferably 5 μm or more. The average particle size of the first phosphor particles is more preferably 40 μm or less, even more preferably 20 μm or less, and particularly preferably 15 μm or less. When the average particle size of the first phosphor particles is 1 μm or more, the first phosphor particles can be dispersed approximately uniformly in the base. When the average particle size of the first phosphor particles is 50 μm or less, the voids in the base are reduced, so that the wavelength conversion efficiency of the irradiated light can be increased. In this specification, the average particle size of the phosphor particles refers to the average particle size (Fisher Sub-Sieve Siezer's Number) measured by the Fisher Sub-Sieve Sizer method (hereinafter also referred to as the "FSSS method").

Preparing First Mixed Liquid In the method for producing a molded body, a first mixed liquid containing second phosphor particles and an aqueous solution of an alkali metal silicate is prepared.

Alkali metal silicate aqueous solution The first mixed liquid contains the second phosphor particles and an alkali metal silicate aqueous solution. The alkali metal silicate aqueous solution preferably contains 10 mass % or more of alkali metal silicate in terms of solid content. Examples of the alkali metal silicate aqueous solution include a sodium silicate aqueous solution, a potassium silicate aqueous solution, and a lithium silicate aqueous solution. The alkali metal silicate aqueous solution is preferably a sodium silicate aqueous solution or a potassium silicate aqueous solution. The alkali metal silicate aqueous solution has an alkali metal content per mole of silicon of preferably 0.1 mol or more, more preferably 0.12 mol or more, even more preferably 0.14 mol or more, preferably 1.5 mol or less, more preferably 1.2 mol or less, and even more preferably 1.0 mol or less. The alkali metal silicate may have a composition represented by the following formula (I). Examples of commercially available alkali metal silicate aqueous solutions include potassium silicate (Ohka Seal (Type A), Ohka Seal (Type B) (manufactured by Tokyo Ohka Kogyo Co., Ltd.)).
A ¹ ₂ O・vSiO ₂・wH ₂ O (I)
(In formula (I), A ¹ is at least one selected from the group consisting of Li, Na, and K, and v and w satisfy 0.4≦v≦3.9 and 5≦w≦90, respectively.)

The alkali metal silicate aqueous solution preferably contains alkali metal silicate in the aqueous solution in a range of 1% by mass to 50% by mass in terms of solid content, and more preferably in a range of 5% by mass to 30% by mass. The first mixed liquid preferably contains an alkali metal silicate aqueous solution in which alkali metal silicate is contained within the above range in terms of solid content per 1 part by mass of phosphor in a range of 50 parts by mass to 200 parts by mass, and more preferably in a range of 80 parts by mass to 150 parts by mass. If the content of the solid content of the alkali metal silicate in the first mixed liquid is in a range of 5% by mass to 30% by mass, the second phosphor particles can be arranged on the substrate in a state in which the second phosphor particles have a portion protruding from the liquid surface of the second mixed liquid described later, and the second phosphor particles can be fixed to the substrate so that unevenness due to the second phosphor particles is formed on the surface of the substrate.

Second phosphor particles The second phosphor particles emit light by light irradiated from a light source, and emit light in a wavelength range different from that of the first phosphor particles. In order to obtain a desired chromaticity, the second phosphor particles are preferably at least one phosphor selected from the group consisting of a fluoride phosphor, an alkaline earth metal silicon nitride phosphor, and an α-sialon phosphor.

It is preferable that the second phosphor particles convert the wavelength of the light irradiated from the light source and emit light having an emission peak wavelength in the range of 600 nm to 690 nm.

In the molded body, when the first phosphor particles have an emission peak wavelength in the range of 530 nm or more and 590 nm or less, it is preferable that the second phosphor particles have an emission peak wavelength in the range of 600 nm or more and 670 nm or less.

In the molded body, when the first phosphor particles have an emission peak wavelength in the range of 490 nm or more and 555 nm or less, it is preferable that the second phosphor particles have an emission peak wavelength in the range of 600 nm or more and 690 nm or less.

When the second phosphor particles are phosphor particles that have an emission peak wavelength in the range of 600 nm to 690 nm by light emitted from a light source, it is preferable that the second phosphor particles are at least one phosphor selected from the group consisting of a fluoride phosphor having a composition represented by the following formula (2A), an alkaline earth metal silicon nitride phosphor having a composition represented by the following formula (2C), an alkaline earth metal silicon nitride phosphor having a composition represented by the following formula (2D), an α-sialon phosphor having a composition represented by the following formula (2E), and an alkaline earth metal silicon nitride phosphor having a composition represented by the following formula (2F).

A ² ₂ [M ² _1-b Mn ⁴⁺ _b F ₆ ] (2A)
In formula (2A), ^A2 is at least one selected from the group consisting of Li, Na, K, Rb, Cs, Fr and _NH4 ⁺ , and ^M2 is a Group 4 element and a Group 14 element. The element is at least one element selected from the group consisting of elements, and b is a number that satisfies 0<b<0.2.

(i-j)MgO・(j/2) ^M32O3 _{・ kMgF2}・_mCaF2・₍ 1-n _{)GeO2・(n/2)M42O3 : zMn4} ⁺ (2B ⁾
In formula (2B), ^M3 is selected from Li, Na, K, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. ^M4 is at least one element selected from the group consisting of Al, Ga, and In, and i, j, k, m, n, and z are The following conditions are satisfied: 2≦i≦4, 0≦j<0.5, 0<k<1.5, 0≦m<1.5, 0<n<0.5, and 0<z<0.05. It is a number.

(Ca _1-p Sr _p )AlSiN ₃ :Eu (2C)
In formula (2C), p is a number that satisfies 0≦p≦1.0.

(Ca _1-q-r Sr _{q Bar} ) ₂ Si ₅ N ₈ :Eu (2D)
In formula (2D), q and r are numbers that satisfy 0≦q≦1.0, 0≦r≦1.0, and q+r≦1.0, respectively.

M ⁵ _c Si _12-(d+e) Al _d+e O _e N _16-e :Eu (2E)
In formula (2E), ^M5 is at least one element selected from the group consisting of Li, Mg, Ca, Sr, Y, and lanthanoid elements (excluding La and Ce); c, d, and and e are numbers satisfying 0<c≦2.0, 2.0≦d≦6.0, and 0≦e≦1.0.

M ⁶ _f M ⁷ _g M ⁸ _h Al _3-s Si _s N _t (2F)
In formula (2F), ^M6 is at least one element selected from the group consisting of Sr, Ca, Ba, and Mg, and ^M7 is at least one element selected from the group consisting of Li, Na, and K. ^M8 is at least one element selected from the group consisting of Eu, Ce, Tb and Mn, and f, g, h, s and t are each within the range of 0.80≦f≦ These numbers satisfy the following conditions: 1.05, 0.80≦g≦1.05, 0.001<h≦0.1, 0≦s≦0.5, and 3.0≦t≦5.0.

When the second phosphor particles are phosphor particles having an emission peak wavelength in the range of 600 _nm or more and 670 _nm or less when irradiated with light from a light source, specific examples of the second phosphor particles include magnesium fluorogermanate phosphors (MGF:Mn) represented by _K2SiF6 :Mn, 3.5MgO.0.5MgF2.GeO2: _Mn4 ⁺ _{, etc.} , _Ca2Si5N8 : _Eu , _{(Ba,Sr)2Si5N8 :} Eu, (Sr, _Ca ) _AlSiN3 : _Eu , _CaAlSiN3 : _Eu , _{Sr0.9925Li1.0000Eu0.0075Al3N4} , _etc.

The average particle size of the second phosphor particles is preferably in the range of 1 μm to 50 μm. The average particle size of the second phosphor particles is preferably 2 μm or more, more preferably 5 μm or more. The average particle size of the second phosphor particles is preferably 40 μm or less, more preferably 30 μm or less. If the average particle size of the second phosphor particles is in the range of 5 μm to 50 μm, the time for the second phosphor particles to be settled on the base body described later is shortened, and workability is improved. If the average particle size of the second phosphor particles is 1 μm to 5 μm, the time for the second phosphor particles to be settled on the base body described later is longer than when the average particle size of the second phosphor particles is 5 μm or more, but the second phosphor particles can be settled more evenly on the surface of the base and the second phosphor particles can be fixed evenly on the surface of the base. Here, "even" means that the particle size of less than 5 μm is longer than that of 5 μm or more, thereby suppressing the variation in the arrangement of the phosphor. Furthermore, if the average particle size of the second phosphor particles is within the range of 1 μm to 50 μm, unevenness caused by the second phosphor particles is likely to be formed on the surface of the substrate. If the average particle size of the second phosphor particles is within the range of 1 μm to 50 μm, the second phosphor particles are fixed to the surface of the substrate by silicon dioxide containing an alkali metal derived from an alkali metal silicate, and mixed color light with improved color rendering is obtained by the second phosphor particles fixed to the substrate, the first phosphor particles in the substrate, and the light irradiated from the light source.

The content of the second phosphor particles in the first mixture is preferably in the range of 0.2% by mass to 1.0% by mass, more preferably in the range of 0.3% by mass to 0.9% by mass, and even more preferably in the range of 0.4% by mass to 0.8% by mass, relative to the total amount of the first mixture. If the content of the second phosphor particles in the first mixture is in the range of 0.2% by mass to 1.0% by mass, relative to the total amount of the first mixture, the second phosphor particles can be settled on the substrate, and the second phosphor particles can be fixed on the substrate so that unevenness due to the second phosphor particles is formed on the substrate. If the amount of the second phosphor particles in the first mixture is too small, it may be difficult to obtain a luminescent color having a desired chromaticity. If the amount of the second phosphor particles in the first mixture is too large, it may be difficult to arrange the second phosphor particles on the substrate so that unevenness due to the second phosphor particles is formed on the substrate.

In the step of preparing the third phosphor particles, the first mixed liquid may further contain third phosphor particles that convert the wavelength of the irradiated light and emit light in a wavelength range different from that of the second phosphor particles. When the first mixed liquid further contains the third phosphor particles, the third phosphor particles can be fixed to the base together with the second phosphor particles so as to form unevenness on the surface of the base. The third phosphor particles fixed to the surface of the base can further convert the wavelength of the light that has passed through the base without being wavelength-converted by the first phosphor particles on the surface of the base, and mixed-color light having a desired chromaticity can be obtained from the molded body.

The third phosphor particles may convert the wavelength of light from the first phosphor particles or the second phosphor particles, but preferably convert the wavelength of light irradiated from a light source. The third phosphor particles can convert the wavelength of light that passes through the base without being wavelength-converted by the first phosphor particles contained in the base, and a mixed color light having a desired chromaticity can be obtained from the molded body by the light that passes through the base, the light that has been wavelength-converted by the first phosphor particles, the light that has been wavelength-converted by the second phosphor particles, and the light that has been wavelength-converted by the third phosphor particles. By making the emission color from the third phosphor particles the same as or similar to the emission color of the first phosphor particles, the emission color of the first phosphor particles is supplemented, and the light emitted from the light emitting device can be shifted in color toward the emission color of the first phosphor particles.

The third phosphor particles may be phosphor particles having a peak emission wavelength in the range of 530 nm to 590 nm when irradiated with light from a light source, or may be phosphor particles having a peak emission wavelength in the range of 490 nm to 555 nm.

When the third phosphor particles are phosphor particles having a peak emission wavelength in the range of 530 nm to 590 nm by light irradiated from a light source, the third phosphor particles may be at least one aluminate phosphor. The aluminate phosphor may be a rare earth aluminate phosphor having a composition represented by the formula (1A). When the third phosphor particles are phosphor particles having a peak emission wavelength in the range of 530 nm to 590 nm by light irradiated from a light source, the _third phosphor particles may be _Y3Al5O12 :Ce _{, Y3(Al,Ga)5O12 : Ce , (} Y,Gd) _{3Al5O12 :} Ce _{, Lu3Al5O12 :} Ce, or _Lu3 (Al,Ga) _5O12 : _Ce .

When the third phosphor particles are phosphor particles having an emission peak wavelength in the range of 490 nm to 555 nm by light irradiated from a light source, the third phosphor particles are preferably at least one phosphor selected from the group consisting of alkaline earth metal silicate phosphors, alkaline earth metal aluminate phosphors, alkaline earth metal halosilicate phosphors, and β-sialon phosphors. When the third phosphor particles are phosphor particles having an emission peak wavelength in the range of 490 nm to 555 nm by light irradiated from a light source, the third phosphor particles may be at least one phosphor selected from the group consisting of alkaline earth metal silicate phosphors having the composition represented by the formula (1B), alkaline earth metal aluminate phosphors having the composition represented by the formula (1C), alkaline earth metal halosilicate phosphors having the composition represented by the formula (1D), and β-sialon phosphors having the composition represented by the formula (1E). When the third phosphor particles are phosphor particles having an emission peak wavelength in the range of 490 nm or more and 555 nm or less when irradiated with light from a light source, specific examples of the third phosphor particles include BaSi ₂ O ₂ N ₂ :Eu, Sr ₄ Al ₁₄ O ₂₅ :Eu, Ca ₈ MgSi ₄ O ₁₆ Cl ₂ :Eu, and Si _6-a Al _a O _a N _8-a :Eu (wherein a is a number satisfying 0<a<4.2).

The average particle size of the third phosphor particles is preferably within the range of 1 μm to 50 μm, similar to the second phosphor particles. The reason why the average particle size of the third phosphor particles is preferably within the range of 1 μm to 50 μm is the same as that of the second phosphor particles.

When the first mixture contains third phosphor particles, the total amount of the second phosphor particles and the third phosphor particles is preferably in the range of 0.2% by mass to 1.0% by mass, more preferably in the range of 0.3% by mass to 0.9% by mass, and even more preferably in the range of 0.4% by mass to 0.8% by mass, relative to the total amount of the first mixture. If the total amount of the second phosphor particles and the third phosphor particles in the first mixture is in the range of 0.2% by mass to 1.0% by mass, relative to the total amount of the first mixture, the second phosphor particles and the third phosphor particles can be settled on the substrate, and the second phosphor particles and the third phosphor particles can be fixed on the substrate so that unevenness due to the second phosphor particles and the third phosphor particles is formed on the substrate. In order to obtain an emission color of the desired chromaticity, the mixing ratio of the second phosphor particles and the third phosphor particles is preferably in the range of 20% by mass to 95% by mass of the third phosphor particles relative to the total amount of the second phosphor particles and the third phosphor particles, and may be in the range of 40% by mass to 92% by mass, or may be in the range of 50% by mass to 90% by mass.

Placing the substrate in an electrolyte solution containing cations In the method for producing a molded body, the substrate is placed in an electrolyte solution containing cations. The cations in the electrolyte solution containing cations are preferably at least one selected from the group consisting of alkaline earth metals, alkali metals, and ammonium. The cations contained in the electrolyte solution are at least one selected from the group consisting of barium ions, strontium ions, calcium ions, potassium ions, sodium ions, and ammonium ions, and more preferably at least one selected from the group consisting of barium ions, potassium ions, and ammonium ions. The electrolyte solution containing cations is preferably an acetic acid solution, a nitrate solution, or a sulfate solution containing at least one selected from the group consisting of alkaline earth metals, alkali metals, and ammonium. The electrolyte solution containing cations is specifically obtained by dissolving barium acetate, barium nitrate, barium sulfate, strontium acetate, strontium nitrate, strontium sulfate, potassium acetate, potassium nitrate, potassium sulfate, or ammonium nitrate in water or deionized water. The electrolyte solution containing cations may also be called a cushion solution. The cation concentration in the electrolyte is in the range of 300 mass ppm to 1000 mass ppm, more preferably in the range of 400 mass ppm to 900 mass ppm, and even more preferably in the range of 500 mass ppm to 800 mass ppm. When the cations in the electrolyte are in the above range, the surface charge of the silanol group (-Si-OH) bonded to the surface of the substrate and the silanol group bonded to the surface of the second phosphor particle is neutralized, the repulsive action between the second phosphor particle and the substrate surface is suppressed, and the condensation reaction of the silanol group on the substrate surface and the silanol group on the surface of the second phosphor particle is promoted. When the first mixture contains third phosphor particles, silanol groups are also bonded to the surfaces of the third phosphor particles.

The electrolyte solution containing cations is preferably in the range of 3 to 10 times, and may be in the range of 4 to 8 times, by mass, relative to the first mixed liquid. The substrate may be placed on a jig capable of lifting the substrate from the electrolyte. Alternatively, the substrate placed on the jig may be placed in a container capable of discharging liquid from the bottom, and the electrolyte solution containing cations may be poured into the container. It is preferable to pour an amount of electrolyte solution containing cations such that the liquid level of the electrolyte is higher than the substrate placed in the container.

Precipitating the second phosphor particles In the manufacturing method of the molded body, the first mixed liquid is added to the electrolyte containing the cations in which the substrate is disposed to form the second mixed liquid, and the second phosphor particles are precipitated on the substrate. When the first mixed liquid contains the third phosphor particles, the third phosphor particles are also precipitated on the substrate together with the second phosphor particles. The time and temperature at which the second phosphor particles are precipitated on the substrate are not limited. It is preferable that the substrate is left stationary when the second phosphor particles are precipitated.

Removing the Supernatant In the method for producing a molded body, after the second phosphor particles are allowed to settle on the substrate, the supernatant of the second mixed liquid is removed. The supernatant of the second mixed liquid is removed without disturbing the second phosphor particles that have settled on the substrate. The supernatant of the second mixed liquid may be removed by sucking with a suction tool, such as a dropper, or may be discharged from the bottom of a container.

After the process of removing the supernatant liquid and before fixing the second phosphor particles, the second phosphor particles are preferably arranged on the surface of the substrate in a state in which at least a portion of the second phosphor particles protrude from the liquid surface of the second mixed liquid. If at least a portion of the second phosphor particles are arranged in a state in which they protrude from the liquid surface of the second mixed liquid, when the second phosphor particles are fixed to the substrate, unevenness caused by the second phosphor particles is easily formed on the surface. If the second phosphor particles are fixed to the substrate so that unevenness caused by the second phosphor particles is formed on the substrate surface, the light emitted by the unevenness is diffusely reflected, and color unevenness can be reduced. If the second phosphor particles are fixed to the substrate so that unevenness is formed on the substrate surface, a thinner silicon dioxide coating can be formed compared to a phosphor layer formed by applying the second phosphor particles dispersed in an inorganic binder, and the demand for thinning can be met. The thickness of the coating of silicon dioxide or the like is not particularly limited, but is preferably in the range of 0.005 μm to 10 μm, and more preferably in the range of 0.1 μm to 5 μm. In addition, since the second phosphor particles are fixed in contact with the base, heat is directly transferred between the second phosphor particles made of ceramic and the base, resulting in high thermal conductivity and excellent heat resistance.

Fixing the second phosphor particles to the substrate by heat treatment In the manufacturing method of the molded body, the substrate and the second phosphor particles arranged on the substrate are heat treated at a temperature range of 60°C to 400°C to fix them. The surface of the substrate and the surface of the second phosphor particles are bonded with silanol groups resulting from the alkali metal silicate. The silanol groups bonded to the surface of the substrate and the silanol groups bonded to the surfaces of the second phosphor particles are dehydrated and condensed to form siloxane bonds (-Si-O-Si-), thereby fixing a part of the second phosphor particles to the substrate so as to contact the substrate. When the third phosphor particles are contained in the first mixture, the silanol groups bonded to the surfaces of the third phosphor particles are dehydrated and condensed to fix a part of the third phosphor particles to the substrate so as to contact the substrate. Hereinafter, the second phosphor particles and the third phosphor particles may be collectively referred to as "phosphor particles". When the silanol groups present on both the surface of the phosphor particles and the surface of the substrate undergo dehydration condensation to form siloxane bonds and the phosphor particles are fixed to the substrate, the film thickness can be made thinner than when the phosphor particles are dispersed in an inorganic binder and applied.

In the step of fixing the second phosphor particles, it is preferable to fix the second phosphor particles with a coating of silicon dioxide containing an alkali metal so as to cover the entire upper surface of the second phosphor particles and the base. The second phosphor particles are fixed to the base by dehydration condensation of silanol groups bonded to the surface of the second phosphor particles and the surface of the base to form siloxane bonds, so that the second phosphor particles are easily fixed by being covered with a coating of silicon dioxide containing an alkali metal so as to cover the entire upper surface of the second phosphor particles and the base. When the first mixture contains third phosphor particles, it is preferable to fix the second phosphor particles and the third phosphor particles by being covered with a coating of silicon dioxide containing an alkali metal so as to cover the entire upper surface of the phosphor particles and the base. The silanol groups bonded to the surface of the phosphor particles and the surface of the base are dehydration condensation to form a coating of silicon dioxide containing an alkali metal. The silicon dioxide coating is formed along the surface of the phosphor particles or the surface of the base, so that unevenness caused by the phosphor particles is easily formed on the surface. In order to fix the second phosphor particles and the entire upper surface of the base with a coating of silicon dioxide containing an alkali metal so as to cover them, it is preferable to perform heat treatment while the surface of the phosphor particles and the base is wet with the second mixed liquid, for example, after removing the supernatant liquid of the second mixed liquid. For example, it is preferable to start the heat treatment within 10 minutes, and preferably within 8 minutes, after removing the supernatant liquid of the second mixed liquid.

In the heat treatment step, the heat treatment temperature may be in the range of 70°C to 350°C, or in the range of 80°C to 300°C. The heat treatment may be performed in an air atmosphere (an atmosphere containing 20% by volume of oxygen) or under atmospheric pressure (101.3 kPa). The heat treatment time may be 1 minute to 1 hour, 2 minutes to 50 minutes, or 5 minutes to 40 minutes. The heat treatment may be performed by placing the base on which the second phosphor particles and, if necessary, the third phosphor particles are arranged in a furnace or the like, or by placing the base on which the second phosphor particles and, if necessary, the third phosphor particles are arranged on a hot plate.

Forming a light-transmitting protective film The manufacturing method of the molded body preferably includes, after fixing the second phosphor particles, forming a light-transmitting protective film on the surface of the coating by atomic layer deposition (ALD). The protective film is preferably formed of, for example, an inorganic material. Specific examples of the inorganic material include aluminum oxide (Al ₂ O ₃ ), silicon dioxide (SiO ₂ ), aluminum nitride (AlN), silicon nitride (Si ₃ N ₄ ), etc., with aluminum oxide being particularly preferred. This allows a dense protective film to be formed on the surfaces of the base, the second phosphor particles, and, if necessary, the third phosphor particles, which can protect the surface of the coating from moisture and the like.

The form of the protective film formed by the atomic deposition method can be identified by observing the cross section or end surface with a scanning electron microscope (SEM) or the like. In other words, it can be identified as a film formed in atomic layer units. Specifically, the atoms that compose the protective film are arranged adjacent to each other so that there are no gaps that would allow water molecules to pass through. In addition, unlike sputtering, CVD, etc., the ALD method has low linearity of the reaction components, so even near obstacles such as unevenness, all reaction components are supplied equally to the film formation site and formed in atomic layers. As a result, even if the surface is uneven due to phosphor particles, a protective film with approximately uniform thickness and good film quality is formed.

The protective film may be a single layer or multilayer film made of one material, or may be a multilayer film made of two or more different materials. A multilayer film can better protect the phosphor particles from moisture and the like, and can improve the extraction of light emitted from the molded body. The protective film preferably has a thickness in the range of, for example, 10 nm to 10 μm. If the thickness of the protective film is in the range of 10 nm to 10 μm, the second phosphor particles and, if necessary, the third phosphor particles can be sufficiently protected, while the reduction in the luminous intensity of the light emitted from the molded body due to the protective film can be suppressed.

The protective film can be formed by atomic deposition, for example, as follows.
First, a substrate on which the second phosphor particles and, if necessary, the third phosphor particles are arranged is introduced into an atomic layer deposition apparatus, and then, for example, trimethylaluminum (TMA) gas is introduced into the atomic layer deposition apparatus to react the OH groups present on the surface of the coating with the TMA. Next, the excess gas is exhausted. After that, H ₂ O gas is introduced to react the TMA bonded to the OH groups in the previous reaction with the H ₂ O. Next, the excess gas is exhausted.
Then, by repeating one cycle of reaction with TMA, evacuation, reaction with OH groups, and evacuation, a protective film of Al ₂ O ₃ having a predetermined thickness can be formed.

Molded body The molded body of the first embodiment is a molded body including a light-transmitting base made of an inorganic material containing first phosphor particles, second phosphor particles arranged on the base, a silicon dioxide coating containing an alkali metal that fixes the second phosphor particles to the base, and a light-transmitting protective film of oxide or nitride having a thickness of 10 nm to 1 μm formed on the coating, and the surface of the molded body is formed with unevenness due to the second phosphor particles. In this specification, the surface of the molded body is formed with unevenness due to the second phosphor particles, which refers to the state before the silicon dioxide coating and protective film are formed. The silicon dioxide coating and protective film are formed along the unevenness due to the second phosphor particles, so unevenness due to the second phosphor particles may be formed in a state where the silicon dioxide coating is formed. The protective film is preferably formed by atomic deposition, and since the protective film is formed along a silicon dioxide coating that is formed along the unevenness caused by the second phosphor particles, the unevenness caused by the second phosphor particles may be formed when the silicon dioxide coating and the protective film are formed.

3 is a schematic cross-sectional view showing a molded body according to the first embodiment. The molded body 31 is a molded body including a light-transmitting base 101 made of an inorganic material 101b containing first phosphor particles 101a, second phosphor particles 102a arranged on the base 101, a coating 103 of silicon dioxide containing an alkali metal with the second phosphor particles 102a fixed to the base 101, and a light-transmitting protective film 104 of oxide or nitride having a thickness within a range of 10 nm to 1 μm formed on the coating 103, and the surface of the molded body 31 has unevenness caused by the second phosphor particles 102a. The second phosphor particles 102a are fixed to the base 101 by silicon dioxide containing an alkali metal derived from an alkali metal silicate solution, so that the second phosphor particles are directly transferred to the base, the thermal conductivity is increased, and the heat resistance is excellent. In addition, if the second phosphor particles 102a are fixed to the surface of the base 101 so that unevenness due to the second phosphor particles 102a is formed, the light emitted by the unevenness is diffused, and the color unevenness of the light emitted from the molded body 31 can be reduced. In addition, the molded body 31 is fixed to the base 101 by the second phosphor particles 102a so that unevenness due to the second phosphor particles 102a is formed on the surface, and a thin silicon dioxide coating 103 and a protective film 104 are formed. Therefore, the thickness of the molded body can be made thinner than a phosphor layer formed by applying second phosphor particles dispersed in an inorganic binder, and the demand for a thinner body can be met.

The average particle size of the second phosphor particles measured by the FSSS method is preferably in the range of 1 μm to 50 μm. The second phosphor particles can be the same as the second phosphor particles described in the manufacturing method of the molded body. If the average particle size of the second phosphor particles is in the range of 5 μm to 50 μm, unevenness due to the second phosphor particles can be formed on the surface of the base. If the average particle size of the second phosphor particles is in the range of 1 μm to 50 μm, the second phosphor particles are fixed to the surface of the base by silicon dioxide containing an alkali metal derived from an alkali metal silicate, and mixed color light with improved color rendering can be obtained by the second phosphor particles fixed to the base, the first phosphor particles in the base, and the light irradiated from the light source.

The thickness of the alkali metal-containing silicon dioxide that fixes the second phosphor particles is preferably 1 μm or less. The second phosphor particles are fixed to the substrate by the alkali metal-containing silicon dioxide derived from the alkali metal silicate aqueous solution contained in the first mixed liquid in the above-mentioned method for producing a molded body, and if the thickness of the alkali metal-containing silicon dioxide is 1 μm or less, the demand for a thinner substrate can be met.

The molded body 31 may have, in the horizontal direction along the surface of the base 101, portions where the second phosphor particles 102a are intermittently present and portions where the second phosphor particles 102a are not present. In the portions of the surface of the base 101 where the second phosphor particles 102a are not present, only silicon dioxide containing an alkali metal may be present.

The molded body 31 emits a mixed color light consisting of light whose wavelength has been converted by the second phosphor particles 102a fixed to the surface of the base 101 so that it has unevenness, light from the light source that has passed through the translucent base 101, and light whose wavelength has been converted by the first phosphor particles 101a contained in the base 101, and the light from the light source, the light whose wavelength has been converted by the first phosphor particles 101a, and the light whose wavelength has been converted by the second phosphor particles 102a can emit a mixed color light with excellent color rendering properties.

Figure 4 is a schematic cross-sectional view showing a molded body according to the second embodiment. The molded body 32 according to the second embodiment differs from the molded body 31 according to the first embodiment in that the base 101 is made of only the first phosphor particles 101a. The first phosphor particles 101a of a predetermined size are sintered and solidified at a predetermined temperature. Since the base 101 can be formed only from the first phosphor particles 101a, it has excellent heat resistance. The surfaces of at least some of the first phosphor particles 101a may be partially or entirely melted, thereby fixing the first phosphor particles 101a together.

Figure 5 is a schematic cross-sectional view showing a molded body according to the third embodiment. The molded body 33 according to the third embodiment is different from the molded body 31 according to the first embodiment in that the phosphor arranged on the surface of the base 101 is arranged with third phosphor particles 102b in addition to the second phosphor particles 102a. This makes it possible to obtain mixed-color light having a desired chromaticity from the molded body. In the molded body 33, third phosphor particles 102b that emit light in a wavelength range different from that of the second phosphor particles 102a and are fixed with silicon dioxide containing an alkali metal are fixed in the horizontal direction along the surface of the base 101. The third phosphor particles 102b may be arranged adjacent to the second phosphor particles 102a in the horizontal direction along the surface of the base 101, or may be arranged away from the second phosphor particles 102a. The third phosphor particles 102b may be arranged in a portion of the surface of the base 101 where the second phosphor particles 102a are not arranged. The third phosphor particles 102b may also be arranged in the concave portions of the concaves and convexes of the second phosphor particles 102a. This allows the second phosphor particles 102a and the third phosphor particles 102b to correct the chromaticity while also reducing the thickness.

The average particle size of the third phosphor particles measured by the FSSS method is preferably in the range of 1 μm to 50 μm. The third phosphor particles can be the same as the third phosphor particles described in the manufacturing method of the molded body. If the average particle size of the third phosphor particles is in the range of 5 μm to 50 μm, unevenness due to the third phosphor particles can be formed on the surface of the base. If the average particle size of the third phosphor particles is in the range of 1 μm to 50 μm, the third phosphor particles are fixed to the surface of the base by silicon dioxide containing an alkali metal derived from an alkali metal silicate, and mixed color light with improved color rendering is obtained by the third phosphor particles fixed to the base, the first phosphor particles in the base, and the light irradiated from the light source.

Light-emitting device The light-emitting device includes the molded article and a light source for irradiating the molded article. The light-emitting device can be used as a light source for a projector, a lighting device, a display device, etc.

The light source is preferably a light emitting _element made of a light emitting diode (LED) or a semiconductor laser (LD) chip, and a semiconductor light emitting element using a nitride semiconductor ( _{InXAlYGa1 -X-} YN, 0≦X, 0≦Y, X+Y≦1) can be used. By using a semiconductor light emitting element as the light source, it is possible to obtain a stable light emitting device that is highly efficient, has high linearity of output relative to input, and is resistant to mechanical shock.

The light source is preferably a semiconductor laser. Light emitted from the semiconductor laser as the light source may be incident on the molded body, and the light whose wavelength has been converted by the molded body may be condensed and separated into red light, green light, and blue light by a plurality of optical systems such as a lens array, a polarization conversion element, and a color separation optical system, and modulated according to image information to form color image light. The light emitted from the semiconductor laser as the light source may be incident on the molded body through an optical system such as a dichroic mirror or a collimating optical system.

The light emitting device preferably has an average color rendering index Ra of 70 or more. The average color rendering index Ra of the light emitting device is more preferably 71 or more, and even more preferably 72 or more. The average color rendering index Ra of the light emitting device can be measured in accordance with JIS Z8726. The closer the average color rendering index Ra of the light emitting device is to 100, the closer the color rendering is to that of the reference light source. If the average color rendering index Ra is 70 or more, it is possible to provide a light emitting device that emits light suitable for lighting applications for general tasks in offices, schools, etc.

Light emitting device (light emitting module)
A light-emitting device having a molded body and a light source, a light-emitting module having a light-emitting device, and a lighting device will be described. The light-emitting device is not limited to the light-emitting module described below. The dimensions, materials, shapes, and relative arrangements of the components of the light-emitting device, light-emitting module, and lighting device described below are merely examples, and are not intended to be limited to the following descriptions unless otherwise specified. Note that the sizes and positional relationships of the components shown in each drawing may be exaggerated to clarify the explanation. In addition, the light-emitting elements shown in each drawing are illustrated with a number set as an example to make the configuration easy to understand.

Figure 6A is a schematic perspective view showing the configuration of a light emitting module, which is an example of a light emitting device, including a light emitting device with a molded body and a light source. Figure 6B is a schematic plan view showing the configuration of a light emitting module, which is an example of a light emitting device, including a light emitting device with a molded body and a light source. Figure 6C is a cross-sectional view taken along line VIC-VIC in Figure 6B. Figure 6D is a cross-sectional view taken along line VID-VID in Figure 6B. Figure 6E is a schematic cross-sectional view showing the configuration of an example of a light emitting device. Figure 6F is a schematic bottom view showing the configuration of an example of a light emitting device.

The light-emitting module 200, which is an example of a light-emitting device, includes a light-emitting device 100 and a module substrate 80 on which the light-emitting device 100 is mounted.

Light Emitting Device The light emitting device 100 will now be described.
The light emitting device 100 has a plurality of light emitting surfaces on the upper surface thereof as light extraction regions of the light emitting device 100 .
The light emitting device 100 includes a submount substrate 10, a light emitting element 20 provided on the submount substrate 10, a light transmitting member 30 made of the above-mentioned molded body provided on the light emitting element 20, a light guiding member 40 disposed between the light transmitting member 30 and the light emitting element 20, an element structure 15 including a first covering member 50 covering a side surface of the light emitting element 20 on the submount substrate 10, and a second covering member 60 covering a side surface of the element structure 15 and holding a plurality of element structures 15. The upper surface of the light transmitting member 30 is exposed from the second covering member 60 and constitutes a plurality of light emitting surfaces provided in the light emitting device 100.
In the light emitting device 100, a plurality of element structures 15, each having a light emitting surface, are held by a second covering member 60. The second covering member 60 makes it possible to hold each of the element structures 15 in a desired arrangement, so that the plurality of light emitting surfaces can be arranged at a narrower distance and with a higher density.
The light emitting device 100 may not use the light guiding member 40 and may directly bond the light transmitting member 30 and the light emitting element 20 to each other.

Each component of the light emitting device 100 will now be described.
The submount substrate 10 is a member on which the light emitting element 20 and the protective element 25 are mounted. The submount substrate 10 is formed, for example, in a substantially rectangular shape in a plan view.
For the submount substrate 10, it is preferable to use an insulating material and a material that is difficult to transmit light emitted from the light emitting element 20 and external light. For example, ceramics such as alumina, aluminum nitride, mullite, etc., thermoplastic resins such as polyamide, polyphthalamide, polyphenylene sulfide, liquid crystal polymer, etc., and resins such as epoxy resin, silicone resin, modified epoxy resin, urethane resin, phenol resin, etc. Among them, it is preferable to use ceramics that have excellent heat dissipation properties.

The submount substrate 10 has wiring on the upper surface, the lower surface, and inside thereof for electrically connecting to the light emitting element 20 and an external power supply. The wiring can be formed using, for example, a metal such as Fe, Cu, Ni, Al, Ag, Au, Al, Pt, Ti, W, or Pd, or an alloy containing at least one of these metals.
For example, the submount substrate 10 may include a substrate having upper surface wiring 2 connected to the light emitting element 20 on the upper surface on which the light emitting element 20 is mounted, and external connection electrodes 3 (e.g., an anode electrode 3a and a cathode electrode 3b) electrically connected to an external power source on the lower surface opposite to the upper surface on which the light emitting element 20 is mounted. In this case, the upper surface wiring 2 and the external connection electrodes 3 may be formed with vias 4 that extend to both the upper and lower surfaces, that is, that penetrate the submount substrate 10. This electrically connects the upper surface wiring 2 and the external connection electrodes 3.

In the light emitting device 100, the distance L1 between adjacent submount substrates 10 may be, for example, 0.05 mm or more and 0.2 mm or less. As a result, the thickness of the second covering member 60 arranged between the submount substrates 10 is 0.05 mm or more and 0.2 mm or less, so that adjacent submount substrates 10 can be densely joined to each other. Also, in a light emitting device 100 having a plurality of element structures 15, each of the plurality of element structures 15 has a submount substrate 10, and the second covering member 60 can be arranged between the submount substrates 10. As a result, the influence of thermal stress due to expansion or contraction of the submount substrate 10 caused by heat generated in each element structure 15 and thermal history during mounting of the light emitting device can be suppressed.

The light emitting element 20 is a semiconductor element that emits light by itself when a voltage is applied. The shape and size of the light emitting element 20 can be selected arbitrarily. The light emitting element 20 can be selected to emit light of any wavelength depending on the application. For example, the light emitting element 20 of blue (light with a wavelength of 430 nm to 500 nm) or green (light with a wavelength of 500 nm to 570 nm) can be made of the above-mentioned nitride-based semiconductor (In _x Al _y Ga _1-X-Y N, 0≦X, 0≦Y, X+Y≦1), GaP, or the like. The light emitting element 20 of red (light with a wavelength of 610 nm to 700 nm) can be made of GaAlAs, AlInGaP, or the like in addition to the nitride-based semiconductor element. The light source of the light emitting device is preferably a semiconductor laser among semiconductor light emitting elements, but a light emitting diode can also be used.

It is preferable to use a light-emitting element 20 that has positive and negative element electrodes on one surface, so that the light-emitting element 20 can be flip-chip mounted to the wiring on the submount substrate 10 using a conductive adhesive 8. As the conductive adhesive 8, for example, eutectic solder, conductive paste, bumps, etc. can be used.

The protective element 25 is, for example, a Zener diode. The protective element 25 has positive and negative element electrodes on one surface, and is flip-chip mounted to the wiring on the submount substrate 10 with a conductive adhesive 8. Note that the light emitting device may not include the protective element 25.

The above-mentioned molded body can be used for the light-transmitting member 30. The light-transmitting member 30 is a flat plate-like member having an upper surface that is the main light-emitting surface of each element structure 15 and the light-emitting device 100, and a lower surface opposite to the upper surface. The light-transmitting member 30 is disposed on the light-emitting element 20. The light-transmitting member 30 preferably has an upper surface that is wider than the upper surface of the light-emitting element 20, and is preferably disposed so as to enclose the light-emitting element 20 in a planar view.
In the light emitting device 100, the distance L2 between the light transparent members 30 exposed on the upper surface of the light emitting device 100 may be, for example, 0.2 mm or less. If the distance L2 between adjacent light transparent members 30 is 0.2 mm or less, the light source can be made smaller. The distance L2 between adjacent light transparent members 30 may be 0.1 mm or less, or 0.05 mm or less. From the viewpoint of ease of manufacturing the light emitting device 100, the distance L2 between the light transparent members 30 may be 0.03 mm or more.

The planar shape of the light-transmitting member 30 can be various, such as a circle, an ellipse, a square, or a polygon such as a hexagon. Among them, from the viewpoint of arranging multiple light-emitting surfaces in close proximity, a rectangular shape such as a square or a rectangle is preferable, and a shape similar to the planar shape of the light-emitting element 20 is even more preferable.

The light-guiding member 40 is disposed between the light-transmitting member 30 and the light-emitting element 20, and is a member that joins the light-emitting element 20 and the light-transmitting member 30. The light-guiding member 40 is a member that makes it easier to extract light from the light-emitting element 20, and guides the light from the light-emitting element 20 to the light-transmitting member 30. The light-guiding member 40 can improve the luminous flux and the light extraction efficiency. The light-guiding member 40 is preferably provided also on the side surface of the light-emitting element 20.
The light guide member 40 covering the side surface of the light emitting element 20 can be formed by spreading the adhesive member that bonds the light transmitting member 30 and the light emitting element 20 onto the side surface of the light emitting element 20 .

The light guide member 40 is formed in a triangular shape in a cross-sectional view such that the width of the member increases from the underside (submount substrate 10 side) of the light emitting element 20 toward the light-transmitting member 30. This configuration makes it easier for light traveling laterally from the light emitting element 20 to be reflected upward, thereby improving the luminous flux and light extraction efficiency. However, the cross-sectional shape of the outer surface of the light guide member 40 is not limited to a linear shape, and may be a curved shape. For example, the curved shape of the light guide member 40 may be a curved shape that bulges toward the first covering member 50 side, or a curved shape that is recessed toward the light emitting element 20 side.

The light-guiding member 40 may cover only the area of the side surface of the light-emitting element 20 that includes the light-emitting portion, but from the viewpoint of improving the luminous flux and light extraction efficiency, it is more preferable that the light-guiding member 40 cover substantially the entire side surface of the light-emitting element 20.
For example, a light-transmitting resin material, glass, or ceramics can be used as the light-guiding member 40. The light-guiding member 40 may contain a diffusing material. This allows light to be more evenly incident on the light-transmitting member 30, and prevents color unevenness in the light-emitting device 100.

The first covering member 50 is provided on the submount substrate 10 and covers the side surface of the light emitting element 20. The first covering member 50 can increase the adhesive strength between the submount substrate 10 and the light emitting element 20. The first covering member 50 covers the side surface of the light emitting element 20 via the light guiding member 40.
The first covering member 50 is formed, for example, in a triangular cross-sectional shape so that the member width increases from the light-transmitting member 30 side toward the submount substrate 10 in a cross-sectional view. The cross-sectional shape of the outer surface of the first covering member 50 is not limited to a linear shape, and may be a curved shape. For example, the curved shape of the first covering member 50 may be a curved shape that bulges toward the second covering member 60 side, or a curved shape that is recessed toward the light-emitting element 20 side.

The first covering member 50 may be, for example, a translucent resin material containing a reflective material. Examples of the resin material used for the first covering member 50 include silicone resin, epoxy resin, and urea resin. In particular, it is preferable to use silicone resin, which has excellent light resistance and heat resistance. Examples of the reflective material include titanium oxide, silica, silicon oxide, aluminum oxide, zirconium oxide, magnesium oxide, potassium titanate, zinc oxide, silicon nitride, and boron nitride. Among these, it is preferable to use titanium oxide, which has a relatively high refractive index, from the viewpoint of light reflection.

The first covering member 50 may cover at least a part of the side surface of the light emitting element 20. Preferably, the first covering member 50 covers the entire side surface of the light emitting element 20. More preferably, the first covering member 50 extends from the side surface of the light emitting element 20 to cover at least a part of the side surface of the light transparent member 30. This makes it possible to suppress the light from the side surface of the light emitting element 20 from being directly emitted to the outside in each element structure 15. This makes it possible to suppress light leakage to adjacent element structures 15 in a light emitting device 100 including a plurality of element structures 15, thereby making it possible to provide a light emitting device 100 with less uneven light emission. In addition, as described below, when a sorting process is performed after the element structures 15 are singulated, the chromaticity coordinates of the element structures 15 can be more easily grasped.
Moreover, the first covering member 50 preferably covers the lower surface of the light emitting element 20. This allows light traveling downward from the light emitting element 20 to be irradiated to and reflected by the reflecting material contained in the first covering member 50, thereby further increasing the luminous flux of the light emitting device 100. In addition, the adhesive strength between the submount substrate 10 and the light emitting element 20 can be further increased.

The second covering member 60 is a member provided around the multiple element structures 15. The second covering member 60 is preferably made of a resin material, but glass or ceramics can also be used. The second covering member 60 is formed by covering the side of the element structure 15 with, for example, a white resin made of a translucent resin material containing a reflective material. That is, the second covering member 60 covers the side of the submount substrate 10, the side of the first covering member 50, and the side of the light-transmitting member 30. The second covering member 60 is also provided between adjacent element structures 15, and covers the outer peripheral side of each of the multiple element structures 15 while exposing the upper surface of the light-transmitting member 30.

The resin material used for the second covering member 60 may be, for example, one of the resin materials exemplified for the first covering member 50. The reflective material contained in the resin used for the second covering member 60 may be, for example, one of the reflective materials exemplified for the first covering member 50.

The light emitting device 100 includes a plurality of element structures 15, each of which includes a first covering member 50 covering a side surface of the light emitting element 20, and therefore can suppress lateral leakage of light emitted from the light emitting element 20. This makes it possible to arrange the plurality of element structures 15 closer to each other without reducing the light extraction efficiency of each element structure 15.
In the light emitting device 100, as an example here, four element structures 15 arranged in a matrix of two rows and two columns are held by the second covering member 60. The element structures 15 are arranged so that the protective elements 25 are located on the outside. This allows the four light transparent members 30 to be arranged in a matrix with narrower intervals. The light emitting device may include three or less element structures 15, or may include five or more element structures 15.

Manufacturing method of light-emitting device The manufacturing method of the light-emitting device 100 includes a submount substrate 10, a light-emitting element 20 provided on the submount substrate 10, a light-transmitting member 30 provided on the light-emitting element 20, a light-guiding member 40 provided on the side of the light-emitting element 20, and a first covering member 50 covering the side of the light-emitting element 20 on the submount substrate 10. An element structure preparation step is a step of preparing a plurality of element structures 15, an element structure mounting step is a step of mounting a plurality of element structures 15 on a sheet member so that the submount substrate 10 of the element structure 15 faces the sheet member, a second covering member formation step is a step of forming a second covering member 60 on the sheet member that covers the side of the plurality of element structures 15 and holds the plurality of element structures 15, and a sheet member removal step is a step of removing the sheet member. In addition to using the above-mentioned molded body as the light-transmitting member 30, the manufacturing method described in Japanese Patent Application No. 2020-006262 can be referenced for the manufacturing method of the light-emitting device.

Light-Emitting Module Next, a light-emitting module 200, which is a light-emitting device, will be described.
The light emitting module 200 includes the light emitting device 100 having the configuration already described, and a module substrate 80 on which the light emitting device 100 is mounted so that the submount substrate 10 of the light emitting device 100 faces the module substrate 80 .
In addition, when the light emitting device 100 does not include the protective element 25, the protective element 25 may be provided on the module substrate 80. Furthermore, the module substrate 80 may be configured to include electronic components other than the protective element 25.

The light emitting device 100 has the configuration as described above.
The module substrate 80 is a member on which the light emitting device 100 is mounted, and electrically connects the light emitting device 100 to the outside. The module substrate 80 is formed, for example, in a substantially rectangular shape in a plan view.
Examples of materials for the module substrate 80 include the materials exemplified as those for use in the submount substrate 10 .
The module substrate 80 has wiring on its upper surface for electrically connecting to the light emitting device 100. Examples of materials for the wiring of the module substrate 80 include the materials exemplified as those used for the wiring of the submount substrate 10. A composite material of an insulating material and a metal member may also be used.

The light emitting device 100 is mounted on the upper surface of the module substrate 80 so that the wiring of the submount substrate 10 and the wiring of the module substrate 80 are joined via a conductive adhesive. Examples of the conductive adhesive that can be used include eutectic solder, conductive paste, bumps, and sintered metal bodies. A strong fixation can be achieved by using a sintered metal body, for example, a metal powder such as silver particles sintered at 160°C or higher, preferably 180°C or higher, and 400°C or lower, preferably 280°C or lower.

When the light emitting module 200 is driven, a current is supplied from an external power source to the light emitting element 20, causing the light emitting element 20 to emit light. Of the light emitted by the light emitting element 20, the light traveling upward is extracted to the outside above the light emitting device 100 via the light transparent member 30. The light traveling downward is reflected by the submount substrate 10 and extracted to the outside of the light emitting device 100 via the light transparent member 30. The light traveling laterally is reflected by the first covering member 50 and/or the second covering member 60 and extracted to the outside of the light emitting device 100 via the light transparent member 30.

A manufacturing method of the light emitting module 200 may include a light emitting device preparation step of preparing the light emitting device 100 using the manufacturing method of the light emitting device 100, and a light emitting device mounting step of mounting the light emitting device 100 so that the submount substrate 10 faces the module substrate 80. The manufacturing method of the light emitting module as the light emitting device can be referred to as described in Japanese Patent Application No. 2020-006262.

A light emitting device including the molded body and a light source can be used as a light source for a projector. An example of a projector will be described with reference to Fig. 7 and Figs. 8A to 8C. Fig. 7 is a schematic side view showing an overview of a light source device 300 for a projector.

As shown in FIG. 7, the light source device 300 includes a light source 310, a condenser lens 320 on which the light emitted from the light source 310 is incident, a phosphor wheel 330 on which the light emitted from the condenser lens 320 is incident, and a light receiving lens 340 on which the light emitted from the phosphor wheel 330 is incident. The phosphor wheel 330 is a disc-shaped phosphor wheel that transmits light from the light source, and is rotated by a drive motor 350 via a drive shaft 352. Note that in FIG. 7, the light source device 300 is shown including the light source 310, the condenser lens 320, the phosphor wheel 330, and the light receiving lens 340, but the light source device 300 may be composed of the light source 310, the condenser lens 320, and the phosphor wheel 330 without including the light receiving lens 340.

Next, an overview of the light source device 300 will be described along the flow of light emitted from the light source 310. In this embodiment, an example will be described in which a semiconductor laser that emits blue light is used as the light source 310. Blue light is emitted from the light source 310, and the emitted blue light enters the condenser lens 320, is condensed by the condenser lens 320, and enters the phosphor wheel 330 rotated by the drive motor 350. The phosphor wheel 330 is made of a material that transmits light, and is provided with a molded body 33 containing phosphor in at least a portion of the area. Not limited to the molded body 33, any of the molded bodies 31, 32, 34, and 35 can be used. The phosphor wheel 330 may be divided into an area where the molded body 33 is provided and an area where the molded body 33 is not provided. If the area is divided into an area where the molded body 33 is provided and an area where the molded body 33 is not provided, when blue light enters the phosphor wheel 330 from the condenser lens 320, the green light of the first phosphor particles, the red light of the second phosphor particles, the yellow light of the third phosphor particles, and the blue light of the light source 310 are emitted from the phosphor wheel 330 and enter the light receiving lens 340. The light is then collimated by the light receiving lens 340 and emitted from the light source device 300. Note that the light receiving lens 340 can not only emit parallel light, but can also emit light in a direction that spreads, or can be focused at a specified position.

7 and 8A to 8C, the structure of the phosphor wheel 330 used in the light source device 300 for a projector will be described. As the phosphor provided in the phosphor wheel 330, the above-mentioned molded body can be used, and for example, the molded body 33 can be used.
The phosphor wheel 330 is a transmissive phosphor wheel that transmits light from the light source 310, and includes, in order from the light source 310 side, a first substrate 332 and a second substrate 334. The first substrate 332 and the second substrate 334 are fixed to a drive shaft 352 of a drive motor 350, and rotate around the drive shaft 352 by the driving force of the drive motor 350. That is, the first substrate 332 and the second substrate 334 are fixed in position relative to each other by the drive shaft 352. However, the method of fixing the relative positions of the first substrate 332 and the second substrate 334 is not limited to the case where the drive shaft 352 is used, and they can be fixed by any other means, for example, by inserting a spacer between the first substrate 332 and the second substrate 334.
The phosphor wheel 330 includes, for example, a molded body 33 between a first substrate 332 and a second substrate 334. In addition, it is preferable that the molded body 33 viewed from the arrow B in Fig. 7 has a base including the first phosphor particles disposed on the first substrate 332 side. It is also preferable that the second phosphor particles 102a and the third phosphor particles 102c of the molded body 33 are disposed on the second substrate 334 side.

The phosphor wheel 330 is provided with a filter 360 on the light source 310 side that transmits light in the wavelength range of light from the light source 310 and reflects light in the wavelength range of light that has been wavelength converted by the first phosphor particles, the second phosphor particles, or the third phosphor particles contained in the molded body 33. In the embodiment shown in FIG. 7, the filter 360 is provided on the light source side of the first substrate 332. Specifically, the filter 360 can be a short-pass filter that transmits light in the blue wavelength range and reflects light in the green, yellow, and red wavelength ranges.

The phosphor wheel 330 is provided with a filter 362 on the side opposite to the light source 310, which transmits light in the wavelength range of light wavelength-converted by the first phosphor particles, the second phosphor particles, and the third phosphor particles, and reflects light in the wavelength range of light from the light source 310. In the embodiment shown in FIG. 7, the filter 362 is provided on the surface of the second substrate 334 opposite to the light source 310, at a position corresponding to the molded body 33 in the rotation direction. Specifically, a long-pass filter that transmits light in the wavelength ranges of green light, yellow light, and red light and reflects blue light can be used as the filter 362. Note that for light in the wavelength range between blue light and red light, for example, light in the wavelength range of yellow light or green light, the filter 362 can transmit or reflect light in a specific wavelength range, and the optimal transmission wavelength range of the filter can be determined depending on the application.

The arrangement on each surface of the first substrate 332 and the second substrate 334 will now be described with reference to Figures 8A to 8C. Figure 8A is a diagram showing the surface of the first substrate 332 of the phosphor wheel 330 facing the light source as viewed from the arrow A in Figure 7. The first substrate 332 is provided with a filter 360 in the area where the molded body 33 is provided on the back side.

Figure 8B is a diagram showing the surface of the second substrate 334 of the phosphor wheel 330 facing the light source as viewed from the arrow B in Figure 7. The second substrate 334 has an area SP in the rotation direction where the molded body 33 is provided, and a blue emission area SB where no phosphor is provided.

Figure 8C is a diagram showing the surface of the second substrate 334 of the phosphor wheel 330 opposite the light source as viewed from the arrow C in Figure 7. The second substrate 334 has a filter 362 provided on the surface opposite the light source side, so as to correspond to the area SP with the molded body 33 on the light source side. In addition, the blue emission region SB does not have phosphor. However, it is also possible to vapor-deposit a dielectric multilayer film, form an anti-reflection film, or form a layer containing a scatterer on the blue emission region SB.

In the phosphor wheel 330 shown in Figures 7 and 8A to 8C, the base of the molded body 33 is arranged on the surface of the first substrate 332 opposite the light source 310, and the second phosphor particles 102a and the third phosphor particles 102b of the molded body are arranged on the surface of the second substrate 334 facing the light source 310.

Description of the Projector Next, a case where the above-mentioned light source device 300 is used as a light source device in a so-called one-chip type DLP projector will be described with reference to Fig. 9. Fig. 9 is a schematic diagram for showing the configuration of a projector 400 according to one embodiment that includes the above-mentioned light source device 300, and is a schematic plan view of the light source device 300 and the projector 400 as viewed from above.
In FIG. 9, the light emitted from the light source device 300 is incident on a DMD (Digital Micromirror Device) element (light modulation means) 470, which is an optical spatial modulator, via an optical system. The light is then reflected by the DMD element 470, condensed by a projection lens 480, which is a projection means, and projected onto a screen 490. The DMD element 470 is a matrix arrangement of fine mirrors corresponding to each pixel of the image projected onto the screen 490, and can turn on/off the light emitted onto the screen by changing the angle of each mirror in microseconds. In addition, by changing the gradation of the light incident on the projection lens depending on the ratio of the time each mirror is turned on to the time it is turned off, gradation display based on the image data of the image to be projected is possible.

In this embodiment, a DMD element is used as the light modulation means, but this is not limited to this, and any other light modulation element can be used depending on the application. Furthermore, the light source device 300 according to the present invention and the projector 400 using this light source device 300 are not limited to the above-mentioned embodiment, and various other embodiments are included in the present invention.
In addition, in this embodiment, the light receiving lens 340 is included in the light source device 300, but this is not limited to the above. For example, the light receiving lens 340 may not be included in the light source device 300, but may be included as part of the optical system.

As described above, the projector 400 in this embodiment includes the above-mentioned light source device 300, a DMD element 470 that forms an image by sequentially modulating light of multiple wavelength bands emitted from the light source device 300 based on image data, and a projection lens 480 that enlarges and projects the image.
By the above steps, a molded article and a light emitting device having excellent color rendering properties and heat resistance can be easily manufactured.

Illumination device An illumination device including a molded body and a light source will be described. The light source may emit laser light. Fig. 10A is a schematic front view showing an outline of an example of the illumination device. Fig. 10B is a schematic cross-sectional view of the illumination device.

The lighting device 500 includes a housing 512, a reflector unit 510, a plurality of laser light source units 515, and a fluorescent member 514 made of the above-mentioned molded body. In FIG. 10A, the plurality of laser light source units 512 are disposed at positions on the rear side of the reflector unit 510 (positions hidden by the reflecting surface 510A).

The emission port 512A of the housing 512 may be provided with a cover 519, and the rear portion 512B of the housing 512 may bulge toward the rear. The housing 512 may be made of a material with high thermal conductivity, such as aluminum.

The laser light source unit 515 includes a laser light source 516, a lens 517, and a heat dissipation member 518. A semiconductor laser (LD) may be used as the laser light source 516. A fiber laser may be used as the laser light source 516. The lens 517 focuses the laser light emitted from the laser light source 516 onto the fluorescent member 514. It is preferable that the multiple laser light source units 515 are arranged at the same angle and at the same distance from the fluorescent member 514. This can prevent the irradiation target from becoming blurred due to overlapping of multiple laser lights, and can prevent the irradiation spot diameter from widening.

The fluorescent member 514 is preferably made of the above-mentioned molded body. The fluorescent member 514 is preferably supported in the center of the reflector unit 510 by a support member 513 that extends from the end of the reflector unit 510 to the center. The support member 513 may be made of a material with high thermal conductivity, such as aluminum.

The reflector unit 510 has a concave shape, and the concave surface is the reflecting surface 510A. The laser light source unit 515 is disposed on the rear side of the reflecting surface 510A of the reflector unit 510. The reflector unit 510 has an annular slit-shaped hole 511 for transmitting the light emitted from the laser light source unit 515 and focusing the light on the fluorescent member 514. The reflector unit 510 may be divided by the hole 511 into a central portion and a circumferential portion that can be separated.

The laser light emitted from the laser light source unit 515 passes through the circular slit-shaped hole 511 and is focused on the fluorescent member 514. The laser light focused on the fluorescent member 514 is wavelength converted by the fluorescent member 514 and is emitted from the fluorescent member 514 toward the reflecting surface 510A of the reflecting mirror unit 510. The light emitted from the fluorescent member 514 is reflected by the reflecting surface 510A of the reflecting mirror unit 510. The light reflected by the reflecting surface 510A becomes parallel light approximately parallel to the optical axis K, and is emitted from the lighting device 500 as illumination light.

The present embodiment will be described in detail below with reference to examples. The present embodiment is not limited to these examples.

First phosphor particle a
The first phosphor particles a _were rare earth _aluminate phosphor particles having _a composition represented by _{Lu2.984Ce0.016Al5O12} (hereinafter also referred to as "LAG phosphor") and an average particle size measured by the FSSS method of 21.5 μm. The first phosphor particles a had an emission peak wavelength in the range of 490 nm to 555 nm. The true density of the LAG first phosphor particles a was 6.69 g/ ^cm3 .

First phosphor particle b
The first phosphor particles b _{were rare} earth _aluminate phosphor particles having a composition represented by _{Y2.955Ce0.045Al5O12} (hereinafter also referred to as "YAG phosphor") and an average particle size measured by the FSSS method of 14.9 μm. The first phosphor particles a had an emission peak wavelength in the range of 530 nm to 590 nm. The true density of the YAG first phosphor particles b was 4.60 g/ ^cm3 .

Second phosphor particle c
As the second phosphor particles, alkaline earth metal silicon nitride phosphor particles having a composition represented by (Sr,Ca) _AlSiN3 :Eu (hereinafter also referred to as "SCASN phosphor") and an average particle size measured by the FSSS method of 12.5 μm were used. The second phosphor particles c had an emission peak wavelength in the range of 600 nm to 670 nm.

Second phosphor particle d
The second phosphor particles were alkaline earth metal silicon nitride phosphor particles having a composition represented by CaAlSiN ₃ :Eu (hereinafter also referred to as "CASN phosphor") and an average particle size measured by the FSSS method of 12.0 μm. The second phosphor particles d had an emission peak wavelength in the range of 600 nm to 670 nm.

Average particle size by FSSS method The average particle size of the first phosphor particles was determined using a Fisher Sub Sieve Sizer Model 95 (manufactured by Fisher Scientific) in an environment of 25°C temperature and 70% relative humidity by measuring out 1 cm3 of sample, packing it in a dedicated tubular container, passing dry air through it at a constant pressure, reading the specific surface area from the differential pressure, and calculating the average particle size by the FSSS method.

Example 1: Preparing a base A1 was prepared, which contained 26.7% by mass of the first phosphor particles a (LAG phosphor) and 73.3% by mass of aluminum oxide, had a relative density of 98.8%, and had a thickness of 0.18 mm. A base B1 was prepared, which contained 13% by mass of the first phosphor particles b (YAG phosphor) and 87% by mass of aluminum oxide, had a relative density of 99.7%, and had a thickness of 0.18 mm. In the examples and reference examples, the relative density of the base was calculated based on the following formulas (1) to (3).

Example 1: Preparing the first mixed solution The second phosphor particles c (SCASN phosphor) and _a potassium silicate aqueous solution represented by _{K2O.3.40SiO2.42.58H2O} (Ohkasil (Type _B ), manufactured by Tokyo Ohka Kogyo Co., Ltd.) were mixed to prepare a first mixed solution. The content of the second phosphor particles d (CASN phosphor) was 0.4 mass% relative to 100 mass% of the first mixed solution. 120 mass parts of potassium silicate aqueous solution were added to 1 mass part of the second phosphor particles c, and pure water was added so that the weight ratio of the aqueous solution of barium acetate described later was 1/6 and the total weight was 50 g, that is, the first mixed solution was 8.57 g (50 g/7), to prepare the first mixed solution.

Example 1: Placing a substrate in an electrolyte solution containing cations A process of applying a phosphor-containing composition to a substrate A barium acetate aqueous solution was prepared as an electrolyte solution (cushion solution) containing cations. The concentration of barium ions in the barium acetate aqueous solution was 736 mass ppm. A barium acetate aqueous solution having a volume six times the volume of the first mixed solution was prepared and poured into a 50 mL beaker. The substrate A1 placed on a jig was placed in the barium acetate aqueous solution.

Example 1: Step of obtaining a molded body by precipitating second phosphor particles on a substrate The first mixed liquid was poured into a barium acetate aqueous solution to obtain a second mixed liquid, and the second phosphor particles c (SCASN phosphor) were precipitated on the substrate A1. The temperatures of the barium acetate aqueous solution, the first mixed liquid, and the second mixed liquid were room temperature (20°C ± 5°C), and the time it took for the second phosphor particles c (SCASN phosphor) to precipitate was within 5 minutes.

Example 1: Removing the supernatant of the second mixed solution After the second phosphor particles c (SCASN phosphor) were allowed to settle on the substrate A1, the supernatant of the second mixed solution was sucked up and removed with a dropper without allowing the second phosphor particles to move.

Example 1: Fixing the second phosphor particles c to the base by heat treatment The base A1 on which the second phosphor particles c (SCASN phosphor) were arranged was taken out of the container together with the jig, and the base A1 was placed on a hot plate while still on the jig, and heat-treated at 80°C for 10 minutes, and the second phosphor particles c were fixed to the base A1 with silicon dioxide containing an alkali metal, to produce a molded body. The heat treatment was started within 5 minutes after removing the supernatant. The heat treatment was performed in an air atmosphere (oxygen content of 20% by volume or more, atmospheric pressure of 101.3 kPa).

Example 2
A molded body was produced in the same manner as in Example 1, except that the base B1 was used as the base and the second phosphor particles d (CASN phosphor) were used as the second phosphor particles.

Example 3
A molded body was produced in the same manner as in Example 2, except that the content of the second phosphor particles d (CASN phosphor) was 0.6 mass % relative to 100 mass % of the first mixed liquid.

Example 4
A protective film was formed by atomic layer deposition (ALD) on the silicon dioxide coating of the molded body manufactured in the same manner as in Example 2. The substrate B1, on which the second phosphor particles d (CASN phosphor) were fixed and covered with a silicon dioxide coating, was introduced into an atomic layer deposition apparatus, trimethylaluminum (TMA) gas was introduced into the atomic layer deposition apparatus, and the OH groups present on the surface of the silicon dioxide coating were reacted with TMA, and excess gas was exhausted. Then, H ₂ O gas was introduced to react the TMA bonded to the OH groups in the previous reaction with H ₂ O. Next, excess gas was exhausted. Then, the reaction of TMA, exhaust, reaction with the OH groups, and exhaust were repeated to form a protective film of Al ₂ O ₃ with a thickness of 17.5 nm, and a molded body with a protective film was obtained.

Reference Example 1
The substrate B1, on which the second phosphor particles were not fixed, was used as the substrate of Reference Example 1.

Reference Example 2
The substrate A1, on which the second phosphor particles were not fixed, was used as the substrate of Reference Example 2.

Comparative Example 1
The same substrate A1 as in Example 1 was used. 50% by mass of an inorganic binder (sol-gel) containing polysilanol, which is a silica precursor, in the range of 1% by mass to 10% by mass and containing isopropyl alcohol as a solvent, and 50% by mass of the second phosphor particles c (SCASN phosphor) were mixed to form a phosphor-containing composition, which was applied to the substrate A1 by a printing method using a mask, and the substrate was placed on a hot plate and dried at 80 ° C. for 3 minutes to remove the solvent contained in the inorganic binder. The thickness of the mask used was 58 μm. The substrate was then heated stepwise at 150 ° C. for 5 minutes, 200 ° C. for 5 minutes, and 250 ° C. for 5 minutes, and then heat-treated at 300 ° C. for 30 minutes after the temperature increase, and the second phosphor particles c (SCASN phosphor) were fixed to the surface of the substrate A1 through a translucent ceramic made of silicon dioxide derived from the inorganic binder to obtain a molded body. Further, in the same manner as in Example 4, a protective film of Al ₂ O ₃ having a thickness of 17.5 nm was formed by atomic layer deposition to obtain a molded body having a protective film formed thereon.

Comparative Example 2
A molded body was obtained in the same manner as in Comparative Example 1, except that the second phosphor particles d (CASN phosphor) were used as the second phosphor particles, the final heat treatment temperature after the stepwise temperature increase was 450° C., and no Al ₂ O ₃ protective film with a thickness of 17.5 nm was formed.

SEM Photos SEM photos of the plan or cross-section (end face) of the molded bodies of each Example and Reference Example were obtained using a scanning electron microscope (product name JSM-IT200, manufactured by JEOL Ltd.) SEM photos are shown in Figs.

SEM-EDS element mapping On the SEM image, elements (Al, O) contained in the substrate and elements (K, Si) contained in the silicon dioxide coating were analyzed by SEM-EDS (scanning electron microscope/energy dispersive X-ray spectrometry). The measurement conditions for SEM-EDS were acceleration voltage: 20 kV, focal length: 11.7 mm, and sample tilt angle: 0°. FIG. 13 shows the SEM-EDS spectrum, and FIG. 15 to FIG. 18 show the SEM-EDS mapping.

Chromaticity x, y due to LED illumination
Each molded body of the Examples and Reference Examples was irradiated with blue light having a wavelength of 455 nm from a bullet-shaped LED, and a handy LED spectroradiometer (product: MK-350, manufactured by UPRtek) was used to measure the transmitted light emitted from the side where the second phosphor particles of each molded body existed at room temperature, and the x, y chromaticity coordinates of the chromaticity diagram in the CIE (International Commission on Illumination: Commission Internationale de l'Eclairage) 1931 color system were obtained from the measured values. The average color rendering index Ra was measured in accordance with JIS Z8726. The input current when measuring the color rendering index Ra was 20 mA to be the rated forward current, and the forward voltage at that time was 3 V.

Heat resistance The side of each molded body of the Examples, Comparative Examples, and Reference Examples where the second phosphor particles were fixed was irradiated with blue laser light having a wavelength of 450 nm and a spot diameter ^{of 0.785} mm2, and the power density of the laser irradiation was increased from 10 to 126 W/ ^mm2 , and the power density of the laser irradiation at which a change occurred in the molded body was measured. The larger the value of the power density (W/ ^mm2 ) of the laser irradiation at which a change occurred in the molded body, the more excellent the heat resistance.

The molded bodies of Examples 2 and 4 were attached to a dicing tape with the side on which the second phosphor particles were fixed facing up, and cut into pieces of 10 x 10 mm size using a dicing device (manufactured by DISCO Corporation), and the width of the fallen part of the second phosphor particles was measured. The fallen width was defined as the width of the largest part of the part where the second phosphor particles fell off from the dicing line.

The molded body according to Example 1 had a laser irradiation density of 47.1 (W/ ^mm2 ) at which degradation was observed, and had heat resistance equal to or greater than that of the molded body of Reference Example 2 in which the second phosphor particles were not fixed to the substrate. The molded bodies of Comparative Examples 1 and 2 in which the second phosphor particles were fixed to the substrate by the sol-gel method began to deteriorate at laser irradiation densities of 5.1 and 10.2 (W/ ^mm2 ), and had low heat resistance. If the sol-gel reacts completely, it becomes an inorganic binder, but if it becomes a thick film, raw materials containing organic matter are likely to remain. It is believed that the heat resistance is low due to the influence of organic residues.

The average color rendering index Ra (CRI) of the transmitted light emitted from the side where the second phosphor particles are present in the molded bodies of Examples 2 and 3 is higher than that of Reference Example 1, and color rendering has been improved by fixing the second phosphor particles. In addition, although the potassium silicate aqueous solution is presumed to have low water resistance, the molded body of Example 4 with a protective film had a smaller falling width than the molded body of Example 2 without a protective film, and the falling width was suppressed. The molded body with a protective film suppressed the falling of the second phosphor particles even during the dicing process in which the molded body is cut while being sprayed with water, reaching a practical level. From this result, the molded body including a protective film can be used in applications where dicing is required.

Fig. 11 is a SEM photograph showing a cross section of a substrate and an end face of a second phosphor particle fixed to the substrate with a coating of silicon dioxide containing potassium according to Example 1. Fig. 12 is an external photograph showing a plane of a molded body in which a second phosphor particle is fixed to the surface of a substrate according to Example 1.
In the molded body according to Example 1, the second phosphor particles were fixed to the surface of the base. It was confirmed that in the molded body according to Example 1, the second phosphor particles were bonded by potassium-containing silicon dioxide, and the surfaces of the second phosphor particles were covered with a silicon dioxide coating.

Fig. 13 is a diagram showing SEM-EDS spectra of the cross section of the base and the surface of the second phosphor particle fixed with silicon dioxide according to Example 1. Fig. 14 is an SEM photograph showing the cross section of the base and the end face of the second phosphor particle fixed with silicon dioxide, for which the SEM-EDS spectrum was measured and SEM-EDS mapping was created according to Example 1. Figs. 15 to 18 show SEM-EDS mapping diagrams showing the location of each element in the SEM photographs of the cross section of the base and the end face of the second phosphor particle fixed with silicon dioxide according to Example 1, with Fig. 15 showing the location where oxygen (O) is present, Fig. 16 showing the location where aluminum (Al) is present, Fig. 17 showing the location where silicon (Si) is present, and Fig. 18 showing the location where potassium (K) is present.
In the SEM-EDS spectrum, peaks of oxygen (O), aluminum (Al), silicon (Si), and potassium (K) can be confirmed for the molded body according to Example 1. Peaks of oxygen (O), silicon (Si), and potassium (K) can be confirmed from the portion of the second phosphor particles 103 on the surface of the substrate. Peaks of strontium (Sr) and the like contained in the second phosphor particles (SCASN) were not confirmed, which indicates that the binder completely coats the particle surface and that the binder is silicon dioxide (SiO2) containing potassium (K) derived from potassium silicate.

In one embodiment of the present invention, the molded article can be used in combination with an LED or LD light source as a wavelength conversion member for light-emitting devices used in lighting devices for vehicles or general lighting, backlights for liquid crystal display devices, and light sources for projectors.

2: upper surface wiring, 3: external connection electrode, 3a: anode electrode, 3b: cathode electrode, 4: via, 8: conductive adhesive, 10: submount substrate, 15: element structure, 20: light emitting element, 25: protective element, 30: light-transmitting member (molded body), 31, 32, 33: molded body, 40: light-guiding member, 50: first covering member, 60: second covering member, 80: module substrate, 100: light emitting device, 101: base, 101a: first phosphor particle, 101b: inorganic material, 102a: second No. 2 phosphor particle, 102b: third phosphor particle, 103: silicon dioxide coating, 104: protective film, 200: light emitting module, 300: light source device, 310: light source, 320: condenser lens, 330: phosphor wheel, 332: first substrate, 334: second substrate, 340: light receiving lens, 350: drive motor, 352: drive shaft, 360: filter, 362: filter, 400: projector, 470: DMD element, 480: projection lens, 490: screen,
500: lighting device, 510: reflector unit, 510A: reflecting surface, 511: hole, 512: housing, 512A: light outlet, 512B: rear surface, 513: support member, 514: fluorescent member, 515: laser light source unit, 516: laser light source, 517: lens, 518: heat dissipation member, 519: cover.

Claims (14)

preparing a light-transmitting base made of an inorganic material containing first phosphor particles, and a first mixed liquid obtained by mixing second phosphor particles and an aqueous solution of an alkali metal silicate;
placing the substrate in an electrolyte solution containing cations;
adding the first mixed solution to the electrolyte to prepare a second mixed solution, and allowing the second phosphor particles to settle on the substrate;
removing a supernatant liquid from the second mixture;
and heat-treating the base and the second phosphor particles disposed on the base at a temperature in the range of 60° C. to 400° C. to fix the second phosphor particles on the base .
a content of the second phosphor particles in the first mixture is within a range of 0.2% by mass to 1.0% by mass with respect to a total amount of the first mixture,
The alkali metal silicate in the aqueous alkali metal silicate solution is in the range of 1% by mass to 50% by mass in terms of solid content,
the first mixture contains the alkali metal silicate aqueous solution in a range of 50 parts by mass or more and 200 parts by mass or less per part by mass of the second phosphor particles, and a solid content of the alkali metal silicate in the first mixture is in a range of 5% by mass or more and 30% by mass or less;
A method for manufacturing a molded body , wherein in the step of fixing the second phosphor particles, the second phosphor particles are fixed with a coating of silicon dioxide containing an alkali metal so as to cover the second phosphor particles and the entire upper surface of the base . The method for producing a molded body according to claim 1 , further comprising forming a light-transmitting protective film on a surface of the coating by atomic deposition after the second phosphor particles are fixed. 3. The method for producing a molded body according to claim 1 or 2, further comprising, after the step of removing the supernatant liquid and before the step of fixing the second phosphor particles, making at least a portion of the second phosphor particles arranged on the substrate have a portion protruding above the liquid surface of the second mixed liquid. The method for producing a molded body according to claim 1 , wherein in the preparing step, the base contains at least one of ceramics and glass. 5. The method for producing a molded body according to claim 4 , wherein in the preparing step, the ceramic is at least one selected from the group consisting of aluminum oxide, aluminum nitride, mullite, and silicon nitride. 6. The method for producing a molded body according to claim 1, wherein in the preparing step, the first phosphor particles are at least one type of phosphor selected from the group consisting of a rare earth aluminate phosphor, an alkaline earth metal silicate phosphor, an alkaline earth metal aluminate phosphor, an alkaline earth metal halosilicate phosphor, and a β-sialon phosphor. 7. The method for producing a molded body according to claim 1, wherein in the preparing step, the second phosphor particles are at least one type of phosphor selected from the group consisting of a fluoride phosphor, an alkaline earth metal silicon nitride phosphor, and an α - sialon phosphor. 8. The method for producing a molded body according to claim 1, wherein in the step of placing the substrate in the electrolytic solution, the cation is at least one selected from the group consisting of alkaline earth metals, alkali metals, and ammonium. The method for producing a molded body according to claim 1 , wherein in the preparing step, the aqueous alkali metal silicate solution is a sodium silicate solution or a potassium silicate solution. a light-transmitting base made of an inorganic material containing first phosphor particles;
second phosphor particles disposed on the substrate;
a silicon dioxide coating containing an alkali metal having the second phosphor particles fixed to the substrate;
a light-transmitting protective film of an oxide or nitride having a thickness of 10 nm to 1 μm formed on the coating,
the thickness of the alkali metal-containing silicon dioxide present between the second phosphor particles and the base is 1 μm or less;
The surface of the molded body is formed with irregularities caused by the second phosphor particles. The molded body according to claim 10 , wherein the volume-based particle size of the second phosphor particles is within a range of 1 μm or more and 50 μm or less, as measured by a laser diffraction particle size distribution measurement method. The molded body according to claim 10 or 11 , further comprising third phosphor particles fixed to a surface of the base, the third phosphor particles emitting light of a wavelength different from that of the second phosphor particles. A light emitting device comprising : the molded body according to claim 10 ; and a light source that irradiates the molded body. The light emitting device according to claim 13 , wherein the light source is a semiconductor laser.

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