TW202046521A - Wavelength conversion member and method for manufacturing same, and light emission device - Google Patents

Abstract

Provided are: a wavelength conversion member which rarely undergoes the decrease in a luminous flux value or the change in chromaticity after lighting; and a light emission device equipped with the wavelength conversion member. A wavelength conversion member 10 characterized by being provided with: a base material layer 1 which comprises a sintered product of a glass powder 1a; and a phosphor layer 2 which is formed on one main surface of the base material layer 1 and comprises a sintered product of a glass powder 2a and a phosphor powder 2b.

Description

Wavelength conversion member, manufacturing method thereof, and light emitting device

The present invention relates to a wavelength conversion member that converts the wavelength of light emitted by a light emitting diode (LED: Light Emitting Diode) or a laser diode (LD: Laser Diode) into other wavelengths, and a manufacturing method thereof, and a light emitting diode Device.

In recent years, as the next generation of light-emitting devices transformed into fluorescent lamps or incandescent lamps, there has been increasing interest in light-emitting devices using LEDs or LDs. As an example of such a next-generation light-emitting device, a light-emitting device combining an LED emitting blue light and a wavelength conversion member that absorbs part of the light from the LED and converts it into yellow light is disclosed. The light emitting device emits white light which is a composite light of blue light emitted from the LED and yellow light emitted from the wavelength conversion member. In Patent Document 1, as an example of the wavelength conversion member, a wavelength conversion member in which inorganic phosphor powder is dispersed in a glass matrix is proposed. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2003-258308

[The problem to be solved by the invention]

In the above-mentioned light-emitting device, after lighting, there is a tendency for the luminous flux value (beam value) to decrease over time, or the chromaticity changes, and there is a problem that the required luminous flux value or chromaticity cannot be obtained.

Therefore, the object of the present invention is to provide a wavelength conversion member that is less likely to cause a decrease in luminous flux value or a change in chromaticity after lighting, and a light emitting device using the same. [Technical means to solve the problem]

The wavelength conversion member of the present invention is characterized by comprising a base layer containing a sintered body of glass powder, and a phosphor layer formed on one main surface of the base layer and containing the sintered body of glass powder and phosphor powder. By adopting such a configuration, it is possible to suppress a decrease in the luminous flux value after lighting or a change in chromaticity. The mechanism can be explained as follows.

The previous wavelength conversion component has a structure in which phosphors are uniformly dispersed throughout the component. Here, the thermal conductivity of the matrix such as glass, which is the dispersion medium of the phosphor, is relatively low. Therefore, the heat generated by the light emission of the phosphor is difficult to conduct into the matrix, and the heat is difficult to release to the outside of the member. As a result, the temperature of the wavelength conversion member becomes a high temperature, and the luminous flux value easily decreases due to the effect of the temperature extinction of the phosphor. If the luminous flux value of fluorescent light decreases, the luminous flux value of the fluorescent component in the emitted light of the wavelength conversion member (combined light of fluorescent light and transmitted excitation light) decreases (in other words, the luminous flux value of transmitted excitation light is relative to the luminous flux of fluorescent light Value becomes relatively large), so the chromaticity of the emitted light changes.

On the other hand, the wavelength conversion member of the present invention has a structure in which a phosphor layer is formed on the surface of the substrate layer. Therefore, it can maintain the mechanical strength of the member itself while increasing the phosphor concentration in the phosphor layer, thereby making the phosphor The light body layer is partially thinned. In this way, the volume of the matrix occupied in the phosphor layer can be reduced, and the thermal conductivity of the phosphor layer can be increased, so that the heat generated by the phosphor can be efficiently released to the outside. As a result, the temperature extinction of the phosphor can be effectively suppressed, and the decrease of the luminous flux value over time can be suppressed. In addition, the substrate layer and the phosphor layer of the wavelength conversion member of the present invention both contain a sintered body containing glass powder, and therefore have excellent adhesion or bonding strength between the two, and excellent mechanical strength of the entire member.

In the wavelength conversion member of the present invention, it is preferable that the thickness of the substrate layer is greater than the thickness of the phosphor layer. In this way, it is possible to easily reduce the thickness of the phosphor layer while maintaining the mechanical strength of the wavelength conversion member, thereby achieving an increase in the phosphor concentration.

In the wavelength conversion member of the present invention, the thickness of the substrate layer is preferably 1.1 to 10 times the thickness of the phosphor layer.

The wavelength conversion member of the present invention preferably has a thickness of the base layer of 45-900 μm.

In the wavelength conversion member of the present invention, the thickness of the phosphor layer is preferably 5-100 μm.

In the wavelength conversion member of the present invention, the content of the phosphor powder in the phosphor layer is preferably 1 to 80% by volume.

In the wavelength conversion member of the present invention, it is preferable that the phosphor powder is a garnet-based phosphor.

The wavelength conversion member of the present invention preferably has a phosphor powder with an average particle size of 1-50 μm.

The wavelength conversion member of the present invention is preferably the glass powder in the substrate layer, which has substantially the same composition as the glass powder in the phosphor layer. In this way, the refractive index difference between the glass in the substrate layer and the glass in the phosphor layer can be eliminated, so the reflection loss at the interface between the two can be reduced. As a result, the emission intensity of the wavelength conversion member can be increased.

The base material layer and/or the phosphor layer of the wavelength conversion member of the present invention may also contain filler powder. In this way, the thermal expansion coefficients of the substrate layer and the phosphor layer can be easily matched, and the warpage or cracks of the member caused by the difference in the thermal expansion coefficient can be suppressed. In addition, the light scattering effect of the filler powder can increase the luminous intensity of the wavelength conversion member. Furthermore, by containing filler powder with high thermal conductivity, the heat dissipation efficiency of the wavelength conversion member can be improved.

The manufacturing method of the wavelength conversion member is used to manufacture the above-mentioned wavelength conversion member, and is characterized by having the following steps: (a) preparing a blank for a substrate layer containing glass powder, and a phosphor containing glass powder and phosphor powder The green sheet for the light body layer; (b) the green sheet laminate is obtained by sandwiching the green sheet for the phosphor layer between a plurality of green sheets for the base material layer; (c) the green sheet laminate is fired, and Obtain a sintered laminated body formed by sandwiching a phosphor layer of a sintered body of glass powder and phosphor powder between two substrate layers of a sintered body of glass powder; and (d) sintering the laminated body One of the substrate layers is removed. If two kinds of green sheets with different materials are laminated and fired, the difference in the amount of shrinkage due to the difference in the coefficient of thermal expansion of each material may cause warpage or cracking. On the other hand, by firing in a state where the phosphor layer green sheet is sandwiched between a plurality of (for example, two) substrate layer green sheets as in the manufacturing method of the present invention, the stress of the entire component can be obtained. It is balanced, so it is not easy to warp or crack during baking. Furthermore, in the sintered laminate after firing, there is also the possibility of residual stress at the interface between the base layer and the phosphor layer due to the difference in thermal expansion coefficient between the two, but the sintered laminate itself has relatively high mechanical strength, so Even if one of the substrate layers is removed by post-processing such as grinding, it is not easy to cause warpage or cracks.

The light-emitting device of the present invention is characterized by having the above-mentioned wavelength conversion member and a light source for irradiating the wavelength conversion member with excitation light of phosphor powder.

In the light-emitting device of the present invention, it is preferable to arrange the wavelength conversion member so that the phosphor layer and the light source face each other. It is particularly preferable that the phosphor layer is directly connected to the light source or via an adhesive layer. For example, in semiconductor elements such as LEDs as light sources, members with excellent thermal conductivity such as sapphire can be used as the light-emitting surface. Therefore, if the phosphor layer is arranged in such a way that it is connected to the light source directly or through an adhesive layer, the heat generated in the phosphor layer can be conducted to the constituent members of the light source and be efficiently released to the outside. [Effects of Invention]

According to the present invention, it is possible to provide a wavelength conversion member that does not easily produce a decrease in luminous flux value or a change in chromaticity after lighting, and a light emitting device using the same.

Hereinafter, preferred embodiments will be described. However, the following embodiments are only examples, and the present invention is not limited to the following embodiments. In addition, in each drawing, components with substantially the same function are sometimes referred to by the same symbols.

Fig. 1 is a schematic cross-sectional view showing a wavelength conversion member according to an embodiment of the present invention. The wavelength conversion member 10 includes a base layer 1 and a phosphor layer 2. The phosphor layer 2 is formed on one main surface of the base layer 1. The base material layer 1 contains a sintered body of glass powder 1a. On the other hand, the phosphor layer 2 contains a sintered body of glass powder 2a and phosphor powder 2b. The planar shape of the wavelength conversion member 10 is not particularly limited, and is, for example, a rectangle such as a square or a circle. Hereinafter, each component is explained in detail.

(Substrate layer) As the glass powder 1a constituting the substrate layer 1, borosilicate glass, phosphate glass, tin phosphate glass, bismuthate glass, tellurite glass, etc. can be used. Examples of borosilicate glass include: SiO ₂ 30 to 85%, Al ₂ O ₃ 0 to 30%, B ₂ O ₃ 0 to 50%, Li ₂ O+Na ₂ O+K ₂ O 0～ 10%, and, MgO＋CaO＋SrO＋BaO 0～50%. Examples of tin phosphate-based glasses include those containing 30 to 90% of SnO and 1 to 70% of P ₂ O ₅ in mole %. Examples of tellurite-based glasses include: TeO ₂ containing 50% or more, ZnO 0-45%, RO (R is at least one selected from Ca, Sr and Ba) 0-50% in molar %, And, La ₂ O ₃ ＋Gd ₂ O ₃ ＋Y ₂ O ₃ 0～50%.

The softening point of the glass powder 1a is preferably 250°C to 1000°C, more preferably 300°C to 950°C, and even more preferably 500°C to 900°C. If the softening point of the glass powder 1a is too low, the mechanical strength or chemical durability of the wavelength conversion member 10 may decrease. In addition, since the glass powder 1a itself has low heat resistance, there is a risk of softening and deformation due to heat generated by the phosphor. On the other hand, if the softening point of the glass powder 1a is too high, the phosphor powder 2b may deteriorate and the luminous intensity of the wavelength conversion member 10 may decrease in the firing step during the production described below. Furthermore, from the viewpoint of improving the chemical stability and mechanical strength of the wavelength conversion member 10, the softening point of the glass powder 1a is preferably 500°C or higher, 600°C or higher, 700°C or higher, 800°C or higher, and more preferably 850°C. ℃ above. Examples of such glass include borosilicate glass. However, if the softening point of the glass powder 1a increases, the firing temperature also increases, and as a result, the manufacturing cost tends to increase. Therefore, from the viewpoint of inexpensively manufacturing the wavelength conversion member 10, the softening point of the glass powder 1a is preferably 550°C or lower, 530°C or lower, 500°C or lower, and 480°C or lower, and particularly preferably 460°C or lower. Examples of such glasses include tin phosphate-based glass, bismuthate-based glass, and tellurite-based glass.

The thickness of the substrate layer 1 is preferably 45-900 μm, 50-500 μm, 70-300 μm, and particularly preferably 90-200 μm. If the thickness of the substrate layer 1 is too small, the mechanical strength of the wavelength conversion member 10 is likely to decrease. On the other hand, if the thickness of the substrate layer 1 is too large, the excitation light or fluorescent light inside the substrate layer 1 is excessively absorbed or scattered, and the luminous intensity of the wavelength conversion member 10 is likely to decrease.

The thickness of the substrate layer 1 is preferably greater than the thickness of the phosphor layer 2. Specifically, the thickness of the substrate layer 1 is preferably 1.1 to 10 times, 1.2 to 7 times, 1.5 to 6 times, 1.8 to 5 times, and particularly preferably 3 to 4 times the thickness of the phosphor layer 2. In this way, the mechanical strength of the wavelength conversion member 10 can be maintained, and the phosphor layer 2 can be easily made thinner, so that the phosphor concentration can be increased.

In this embodiment, the base material layer 1 contains only the powder sintered body of the glass powder 1a, but it is not limited to this. For example, the base material layer 1 may contain other inorganic powders such as filler powder in order to adjust the thermal expansion coefficient or obtain a light scattering effect. In this way, the thermal expansion coefficient of the base material layer 1 and the phosphor layer 2 can be easily matched, and the generation of warpage or cracks of the wavelength conversion member 10 caused by the difference in the thermal expansion coefficient can be suppressed. In addition, the light scattering effect of the filler powder can increase the luminous intensity of the wavelength conversion member 10. Furthermore, by containing the filler powder with high thermal conductivity, the heat dissipation efficiency of the wavelength conversion member 10 can be improved. Examples of the filler powder include MgO, Al ₂ O ₃ , BN, AlN, and the like. Among them, MgO, Al ₂ O ₃ , and BN have excellent transmittance in the visible light range and are therefore preferable.

(Phosphor layer) As the glass powder 2a constituting the phosphor layer 2, the same as those exemplified as the above-mentioned glass powder 1a can be used. Here, it is preferable that the difference in refractive index between the glass powder 1a in the substrate layer 1 and the glass powder 2a in the phosphor layer 2 is small. For example, the difference between the refractive index (nd) of the glass powder 1a and the glass powder 2a is preferably 0.2 or less, 0.1 or less, more preferably 0.05 or less, and most preferably the same refractive index. In this way, the refractive index difference between the sintered body part of the glass powder 1a and the sintered body part of the glass powder 2a can be reduced, and therefore the reflection loss at the interface between the two can be reduced. As a result, the luminous intensity of the wavelength conversion member 10 can be increased.

In addition, as described below, the base material layer 1 and the phosphor layer 2 are produced by laminating and firing green sheets that are basically the raw materials of each layer. Therefore, the difference between the softening points of the glass powder 1a and the glass powder 2a is preferable Smaller. For example, the difference between the softening points of the glass powder 1a and the glass powder 2a is preferably 100°C or less, 50°C or less, 30°C or less, more preferably 10°C or less, and most preferably the same softening point.

From the above viewpoint, it is preferable that the glass powder 1a and the glass powder 2a have substantially the same composition. Furthermore, the so-called "having substantially the same composition" means that the components deliberately contained in the glass composition have the same composition, and that it is unavoidably mixed as impurities (specifically, at a level of less than 0.1 mol%) The ingredients are not considered.

The phosphor powder 2b is not particularly limited as long as it emits fluorescence by the incidence of excitation light. Specific examples of the phosphor powder 2b include, for example, phosphor powder selected from oxide phosphor powder, nitride phosphor powder, oxynitride phosphor powder, chloride phosphor powder, oxychloride phosphor Powder, sulfide phosphor powder, oxysulfide phosphor powder, halide phosphor powder, chalcogenide phosphor powder, aluminate phosphor powder, halophosphorus oxychloride phosphor One or more of powder and garnet-based compound phosphor powder. Among them, garnet-based phosphors have excellent heat resistance and are therefore preferred. When blue light is used as the excitation light, for example, phosphor powder that emits green light, yellow light or red light as fluorescence can be used.

The average particle diameter of the phosphor powder 2b is preferably 1-50 μm, more preferably 5-25 μm. If the average particle diameter of the phosphor powder 2b is too small, the luminous intensity may decrease. On the other hand, if the average particle size of the phosphor powder 2b is too large, the luminous color may become uneven. In addition, there is a tendency that thinning of the phosphor layer 2 becomes difficult.

The phosphor powder 2b in the phosphor layer 2 may also contain a plurality of phosphor powders with different average particle diameters. In this way, as the filling rate of the phosphor powder 2b in the phosphor layer 2 is increased, the grounding points between the phosphor powder 2b are increased, and it is easy to construct a heat conduction path. As a result, the heat dissipation efficiency of the wavelength conversion member 10 can be improved.

The content (filling rate) of the phosphor powder 2b in the phosphor layer 2 is preferably 1 to 80% by volume, 10 to 78% by volume, 20 to 76% by volume, 30 to 74% by volume, and particularly preferably 40 to 72 volume%. If the content of the phosphor powder 2b is too small, in order to obtain the desired luminous color, the thickness of the phosphor layer 2 must be increased. As a result, the internal scattering of the phosphor layer 2 may increase and the light extraction efficiency may decrease. . On the other hand, if the content of the phosphor powder 2b is too large, the compactness of the phosphor layer 2 is likely to decrease. As a result, the number of pores in the phosphor layer 2 may increase, and internal scattering may increase, and the light extraction efficiency may decrease.

The thickness of the phosphor layer 2 is preferably 5 to 100 μm, 10 to 90 μm, 15 to 80 μm, and particularly preferably 20 to 70 μm. If the thickness of the phosphor layer 2 is too small, it may be difficult to obtain sufficient luminous intensity. Or, in order to obtain the desired luminous color, the content of the phosphor powder 2b must be increased, and the compactness of the phosphor layer 2 is liable to decrease. On the other hand, if the thickness of the phosphor layer 2 is too large, the scattering or absorption of light in the phosphor layer 2 may become too large, and the emission efficiency of fluorescent light or excitation light may decrease.

In this embodiment, the phosphor layer 2 includes only the powder sintered body of the glass powder 2a and the phosphor powder 2b, but it is not limited to this. For example, similarly to the base layer 1, in order to adjust the thermal expansion coefficient or obtain a light scattering effect, the phosphor layer 2 may contain other inorganic powders such as filler powder. In this way, the thermal expansion coefficients of the base material layer 1 and the phosphor layer 2 can be easily matched, and the generation of warpage or cracks of the wavelength conversion member 10 due to the difference in thermal expansion coefficient can be suppressed. In addition, the light scattering effect of the filler powder can increase the luminous intensity of the wavelength conversion member 10. Furthermore, by containing the filler powder with high thermal conductivity, the heat dissipation efficiency of the wavelength conversion member 10 can be improved. In addition, the filler powder may be contained in only one of the base material layer 1 and the phosphor layer 2, or the filler powder may be contained in both.

(Method of manufacturing wavelength conversion component) Fig. 2 is a schematic diagram showing a method of manufacturing a wavelength conversion member according to an embodiment of the present invention. First, in step (a), a green sheet 1'for a base material layer containing glass powder 1a and a green sheet 2'for a phosphor layer containing glass powder 2a and phosphor powder 2b are prepared as follows.

A slurry is produced by adding organic components such as a binder resin or a solvent to the glass powder 1a and kneading it. By coating the prepared slurry on a supporting substrate, a doctor blade provided at a specific interval from the supporting substrate moves relative to the slurry to produce a green sheet 1'for the substrate layer (doctor blade method) ). As the supporting substrate, for example, a resin film such as polyethylene terephthalate can be used.

In addition, an organic component such as a binder resin or a solvent is added to the mixed powder of the glass powder 2a and the phosphor powder 2b and kneaded to prepare a slurry. Using the obtained slurry, a green sheet 2'for the phosphor layer was produced by the same doctor blade method as described above.

Next, in the step (b), the green sheet laminate 20' is obtained by sandwiching the phosphor layer green sheet 2'between the plurality of base material layer green sheets 1'. Here, in order to improve the adhesiveness of each layer, it is preferable to pressurize the green sheets after the green sheets are laminated. Furthermore, in this embodiment, the green sheet laminate 20' is produced by sandwiching one green sheet 2'for the phosphor layer between two green sheets 1'for the base material layer, but it is not limited to this. . For example, in order to adjust the thickness of each layer, the green sheet 1'for the base material layer or the green sheet 2'for the phosphor layer may each include a plurality of green sheets.

Then, in step (c), by firing the green sheet laminate 20', it is obtained that the glass powder 2a and the phosphor powder are sandwiched between the two substrate layers 1 of the sintered body containing the glass powder 1a. 2b is a sintered layered body 20 made of the phosphor layer 2 of the sintered body. Generally, the green sheet shrinks greatly during firing. Therefore, if two kinds of green sheets with different materials are laminated and fired, the difference in the amount of shrinkage due to the difference in the coefficient of thermal expansion of each material may cause warpage or cracking. On the other hand, in this embodiment, by firing in a state where the phosphor layer green sheet 2'is sandwiched between the two substrate layer green sheets 1', the stress balance of the entire member can be achieved. Therefore, it is not easy to warp or crack during baking.

The firing temperature is preferably within ±150°C of the softening point of glass powder 1a and glass powder 2a, and more preferably within ±100°C of the softening point of glass powder 1a and glass powder 2a. If the firing temperature is too low, the glass powder 1a and the glass powder 2a may not soften and flow, and a dense sintered body may not be obtained. On the other hand, if the firing temperature is too high, the phosphor powder 2b may deteriorate and the luminous intensity may decrease.

Finally, in step (d), the wavelength conversion member 10 is obtained by removing one of the base material layers 1 in the sintered laminate 20. The base material layer 1 can be removed by polishing or grinding, for example. In the sintered laminate 20 after firing, there is a possibility of residual stress at the interface between the base layer 1 and the phosphor layer 2 due to the difference in thermal expansion coefficient between the two. However, the mechanical strength of the sintered laminate 20 itself is relatively high, so Even if one of the base material layers 1 is removed by post-processing such as grinding, it is not easy to cause warpage or cracks.

Furthermore, in order to adjust the overall thickness of the wavelength conversion member 10, or to adjust the surface roughness of the wavelength conversion member 10, the unremoved base layer 1 may be subjected to grinding or grinding processing. For example, when the unremoved base layer 1 becomes the light-emitting surface, the surface roughness of the base layer 1 is preferably 0.01-0.25 μm, 0.03-0.24 μm, 0.05-0.23 μm, and particularly preferably 0.06-0.22 μm. In this way, the light extraction efficiency of excitation light and fluorescent light is easily improved.

(Light-emitting device) 3 is a schematic cross-sectional view of a light emitting device using a wavelength conversion member according to an embodiment of the present invention.

The light emitting device 100 includes a substrate 3, a light source 4, a wavelength conversion member 10 and a reflection member 5. Specifically, the light source 4 and the wavelength conversion member 10 are sequentially arranged on the substrate 3 so that the reflection member 5 covers the periphery of the light source 4 and the wavelength conversion member 10. With this configuration, the excitation light generated by the light source 4 undergoes wavelength conversion in the phosphor layer 2 of the wavelength conversion member 10 to become fluorescent light, and passes through the substrate layer together with the excitation light without wavelength conversion 1 and release to the outside.

The wavelength conversion member 10 is installed so that the side of the phosphor layer 2 faces the light source 4. Specifically, the wavelength conversion member 10 is arranged in such a way that the phosphor layer 2 and the light source 4 are connected. Alternatively, the phosphor layer 2 may be provided in such a way that it is connected to the light source via an adhesive layer (not shown). As the light source 4, semiconductor elements such as LEDs or LDs can usually be used. However, since a member with excellent thermal conductivity such as sapphire is used as the light-emitting surface of the semiconductor element, if it is in direct contact with the light source 4 or through an adhesive layer The arrangement of the phosphor layer 2 allows the heat generated by the phosphor layer 2 to be conducted to the constituent members of the light source 4 and is efficiently released to the outside.

As the substrate 3, for example, white LTCC (Low Temperature Co-fired Ceramics) which efficiently reflects the light emitted from the light source 4 can be used. Specifically, a sintered body of inorganic powder such as alumina, titanium oxide, and niobium oxide and glass powder can be cited.

In addition, as the substrate 3, in order to efficiently release the heat emitted from the light source 4, a material with higher thermal conductivity may be used. Especially in terms of excellent heat resistance and weather resistance, it is preferable to use a ceramic-containing substrate or the like. Specifically, ceramic substrates such as alumina and aluminum nitride can be cited.

The reflective member 5 can also be used to reflect the light source 4 and the light leaking from the wavelength conversion member 10. The reflective member 5 may be formed of, for example, a resin (highly reflective resin) containing a white color such as titanium oxide. [Example]

Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited to these examples.

(Example) (i) The glass powder is made into a glass composition of SiO ₂ 61%, Al ₂ O ₃ 4%, B ₂ O ₃ 5%, CaO 16%, BaO 12%, and ZnO 2% in terms of mole% In this way, the raw materials are prepared and melted and vitrified at 1200-1700°C for 1 to 2 hours using a platinum crucible. The molten glass flows out between a pair of cooling rolls to form a film. The obtained film-like glass molded body was pulverized by a ball mill, and then classified to obtain glass powder having an average particle diameter D ₅₀ of 2.5 μm (softening point 850° C., refractive index (nd) 1.58). Furthermore, the softening point uses the fiber extension method, and the temperature at which the viscosity becomes 10 ^7.6 dPa·s.

(ii) Production of blanks for substrate layer By adding a binder resin (OliCox manufactured by Kyoeisha Chemical Co., Ltd.) and plasticizer (DOA manufactured by Huying Chemical Industry Co., Ltd.) and dispersant (manufactured by Kyoeisha Chemical Co., Ltd.) to the glass powder Flowlen G-700) and organic solvent (methyl ethyl ketone) are kneaded to obtain a slurry mixture. The obtained slurry-like mixture was formed into a sheet shape by a doctor blade method, and dried at room temperature to obtain a green sheet for a base material layer having a thickness of 220 μm.

(iii) Preparation of the green sheet for the phosphor layer: Mix the phosphor powder (Y ₃ Al ₅ O ₁₂ : Ce, average particle size D ₅₀ = 15 μm) with the glass powder, and add a binder resin (Kyoeisha Chemical Co., Ltd.) OliCox manufactured by Co., Ltd.) and plasticizer (DOA manufactured by Huying Chemical Industry Co., Ltd.), dispersant (Flowlen G-700 manufactured by Kyoeisha Chemical Co., Ltd.), and organic solvent (methyl ethyl ketone) Kneading to obtain a slurry-like mixture. The obtained slurry mixture was formed into a sheet by a doctor blade method and dried at room temperature to obtain a green sheet for a phosphor layer with a thickness of 120 μm. Furthermore, the amount of phosphor powder added is such that the total amount of glass powder and phosphor powder becomes 60% by volume (in the characteristic evaluation test described below, white light is obtained when the excitation light source is irradiated. Light body density) to adjust.

Furthermore, the "white light" in this embodiment is defined as follows. That is, from the CIE 1931 2-deg, x(＿), y(＿), z(＿) color matching function, the energy distribution spectrum is integrated to obtain the tristimulus value XYZ, and then the color degree is calculated by the tristimulus value XYZ When x=X/(X+Y+Z) and chromaticity y=Y/(X+Y+Z), these values refer to light that becomes x=0.33 and y=0.33, respectively.

(iv) Fabrication of wavelength conversion components After cutting the green sheet for the base material layer and the green sheet for the phosphor layer to a specific size, the green sheet for the phosphor layer is sandwiched between the two green sheets for the base layer and heated by a press Press bonding to obtain a green sheet laminate. After debinding the green sheet laminate in an electric furnace, in a vacuum gas displacement furnace, vacuum firing is performed near the softening point of the glass powder. Thereby, a sintered laminate obtained by sandwiching the phosphor layer including the sintered body of glass powder and phosphor powder between the two substrate layers of the sintered body including glass powder is obtained.

By grinding the sintered layered body, one of the base material layers is removed. The remaining substrate layer and phosphor layer are polished to a mirror surface state, thereby obtaining a wavelength conversion member having a substrate layer with a thickness of 90 μm and a phosphor layer with a thickness of 30 μm formed on one main surface thereof.

(v) Characteristic evaluation test With respect to the obtained wavelength conversion member, the total luminous flux value and chromaticity change over time were measured in the following manner.

The wavelength conversion member is adhered to an LED light source with an excitation wavelength of 450 nm through a silicone resin adhesive, and the outer periphery of the LED light source and the wavelength conversion member are covered by the reflective member, thereby obtaining a light emitting device. Here, the wavelength conversion member is arranged so that the phosphor layer side faces the light source. A direct current of 1.0 A was applied to the light-emitting device to turn on the light source. After the light emitted from the wavelength conversion member is absorbed by the inside of the integrating sphere, it is guided to a spectroscope calibrated according to the standard light source, and the energy distribution spectrum of the light is measured. Calculate the total luminous flux value by matching the standard specific visual sensitivity with the obtained spectrum. The total luminous flux value was continuously measured after the light source was turned on until after 180 seconds had elapsed. As a result, when it was set to 1 immediately after lighting, the change rate of the total luminous flux value was 0.96.

In addition, the chromaticity x calculated from the following formula was continuously measured after the light source was turned on until 180 seconds passed. As a result, the amount of change (the amount of decrease) was 0.002.

(Comparative example) Using the same method as in Example 1, a green sheet for the phosphor layer with a thickness of 320 μm was obtained. Furthermore, the amount of phosphor powder added is such that the total amount of glass powder and phosphor powder becomes 8.5% by volume (in the characteristic evaluation test, the fluorescent white light obtained when the excitation light source is irradiated Body concentration) to adjust.

After debinding the green sheet for the phosphor layer cut to a specific size in an electric furnace, it is subjected to vacuum firing in a vacuum gas displacement furnace near the softening point of the glass powder. The sintered body of the glass powder and phosphor powder obtained by grinding is made into a mirror state, and a wavelength conversion member with a thickness of 120 μm is obtained.

With respect to the obtained wavelength conversion member, the same characteristic evaluation test as in the examples was performed. As a result, when set to 1 immediately after lighting, the change rate of the total luminous flux value was 0.91, and the change amount (decrease amount) of the chromaticity x was 0.012.

From the above, it can be seen that the luminous flux value of the wavelength conversion member of the present invention decreases with time or the chromaticity changes less after lighting, and it is easy to obtain the required luminous flux value or chromaticity.

1: substrate layer 1a: glass powder 1': Green sheet for base layer 2: Phosphor layer 2a: glass powder 2b: Phosphor powder 2': Green sheet for phosphor layer 3: substrate 4: light source 5: reflective component 10: Wavelength conversion component 20: Sintered laminated body 20': Blank laminated body 100: Light-emitting device

Fig. 1 is a schematic cross-sectional view showing a wavelength conversion member according to an embodiment of the present invention. 2(a) to (d) are schematic diagrams showing a method of manufacturing a wavelength conversion member according to an embodiment of the present invention. 3 is a schematic cross-sectional view of a light emitting device using a wavelength conversion member according to an embodiment of the present invention.

Claims (14)

A wavelength conversion component is characterized by having: A substrate layer of a sintered body containing glass powder; and A phosphor layer formed on one main surface of the substrate layer and containing a sintered body of glass powder and phosphor powder. The wavelength conversion member of claim 1, wherein the thickness of the substrate layer is greater than the thickness of the phosphor layer. The wavelength conversion member of claim 2, wherein the thickness of the substrate layer is 1.1-10 times the thickness of the phosphor layer. The wavelength conversion member according to any one of claims 1 to 3, wherein the thickness of the substrate layer is 45-900 μm. The wavelength conversion member according to any one of claims 1 to 4, wherein the thickness of the phosphor layer is 5-100 μm. The wavelength conversion member according to any one of claims 1 to 5, wherein the content of the phosphor powder in the phosphor layer is 1 to 80% by volume. The wavelength conversion member according to any one of claims 1 to 6, wherein the phosphor powder is a garnet-based phosphor. The wavelength conversion member according to any one of claims 1 to 7, wherein the average particle diameter of the phosphor powder is 1-50 μm. The wavelength conversion member according to any one of claims 1 to 8, wherein the glass powder in the substrate layer and the glass powder in the phosphor layer have substantially the same composition. The wavelength conversion member according to any one of claims 1 to 9, wherein the substrate layer and/or the phosphor layer contains filler powder. A method for manufacturing a wavelength conversion member, which is used to manufacture the wavelength conversion member according to any one of Claims 1 to 10, characterized by having the following steps: (a) Prepare a green sheet for a substrate layer containing glass powder and a green sheet for a phosphor layer containing glass powder and phosphor powder; (b) The green sheet laminate is obtained by sandwiching the green sheet for the phosphor layer between a plurality of the green sheets for the base layer; (c) By firing the above-mentioned green sheet laminate, a phosphor layer in which a sintered body including the above glass powder and phosphor powder is sandwiched between two substrate layers of a sintered body including the above glass powder is obtained The sintered laminate; and (d) Remove one of the above-mentioned base material layers in the above-mentioned sintered laminate. A light emitting device, characterized by comprising: the wavelength conversion member according to any one of claims 1 to 10, and a light source for irradiating the wavelength conversion member with excitation light of the phosphor powder. The light-emitting device of claim 12, wherein the wavelength conversion member is arranged such that the phosphor layer and the light source are opposed to each other. The light-emitting device of claim 13, wherein the phosphor layer is directly connected to the light source or via an adhesive layer.

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