Wavelength conversion member and light emitting device

Abstract

The present invention relates to a wavelength conversion member and a manufacturing method thereof, the wavelength conversion member comprising a glass matrix, a phosphor powder and a spherical silica filler powder dispersed in the glass matrix, the spherical silica filler powder having D50 and SPAN values ​​within a specific range. The wavelength conversion member has high fluorescence intensity, excellent optical properties such as light transmittance, luminous flux, and converted luminous flux, and can suppress the decrease in luminous intensity over time when irradiated with high-power excitation light, and can be effectively used in light-emitting devices.

Description

[Technical field]

[0001] Technical Field The present invention relates to a wavelength conversion member and a light emitting device including the same, and more particularly to a wavelength conversion member including a spherical silica filler powder having a particle size distribution within a specific range, and a light emitting device including the same. [Background technology]

[0002] Background technology 2. Description of the Related Art In recent years, light-emitting devices using an excitation light source such as a light-emitting diode (LED) have been attracting attention as next-generation light-emitting devices from the viewpoints of low power consumption, light weight, ease of light quantity control, and the like.

[0003] Such a light emitting device generally includes a blue LED and a wavelength conversion member that absorbs the blue light emitted from the blue LED and generates white light through yellow, green, or red light. The wavelength conversion member generally has a structure in which phosphor powder is dispersed in an organic or inorganic matrix.

[0004] Specifically, a wavelength conversion member in which phosphor powder is dispersed in a resin matrix is ​​used. However, the wavelength conversion member has problems in that the resin deteriorates due to heat from the excitation light source and the irradiated light, and the luminance of the light-emitting device decreases.

[0005] On the other hand, Japanese Patent Application Laid-Open No. 2003-258308 and Japanese Patent No. 4895541 disclose a method for producing a wavelength conversion member in which phosphor powder is dispersed in a glass matrix (or glass base material). However, when a glass matrix is ​​used, some phosphors may deteriorate due to the high sintering temperature during the production of the wavelength conversion member, which may cause a decrease in optical properties and discoloration, and there is a problem that it is difficult to realize a wavelength conversion member with high color rendering properties due to restrictions on the use of phosphors.

[0006] Furthermore, in such wavelength conversion materials, the excitation light from the LED may not be sufficiently scattered inside the wavelength conversion material, causing the light emitted from the light-emitting device to become non-uniform, resulting in a decrease in the intensity of the fluorescent light.

[0007] To solve this problem, methods of increasing the content of phosphor powder have been considered, but in this case, although the amount of light scattered inside the wavelength conversion member can be increased, the color shift becomes large, and there is a limit to obtaining good colors. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2003-258308 A [Patent Document 2] Patent No. 4895541 Summary of the Invention [Problem to be solved by the invention]

[0009] Disclosure of the Invention technical challenges The present invention has been devised to solve the above problems of the prior art. The technical problem to be solved by the present invention is to provide a wavelength conversion member having high fluorescence intensity and excellent optical properties. In particular, the present invention provides a wavelength conversion member capable of suppressing the decrease in luminescence intensity over time when irradiated with high-power excitation light, and a method for producing the same.

[0010] Another technical problem to be solved by the present invention is to provide a light emitting device including the above wavelength conversion member. [Means for solving the problem]

[0011] Solution to the problem Effect of the Invention The wavelength conversion member of the present invention has high fluorescence intensity, excellent optical properties such as light transmittance, luminous flux, and converted luminous flux, and can suppress a decrease in luminescence intensity over time when irradiated with high-power excitation light, and can therefore be advantageously used in light-emitting devices. [Brief description of the drawings]

[0012] BRIEF DESCRIPTION OF THE DRAWINGS The present invention will now be described in more detail with reference to the drawings. [Figure 1] FIG. 1 is a plan view diagrammatically illustrating a wavelength conversion member according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram showing a method for measuring the major axis diameter and minor axis diameter of a spherical silica filler powder according to one embodiment of the present invention. [Diagram 3] FIG. 3 is a process flow diagram showing a method for producing a wavelength conversion member according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] BEST MODE FOR CARRYING OUT THE PRESENTINVENTION The present invention is not limited to the contents disclosed below, and various modifications can be made without departing from the spirit and scope of the present invention.

[0014] In this specification, when a part is said to "comprise" an element, unless otherwise indicated, it should be understood that the part can include other elements as well.

[0015] In this specification, unless otherwise specified, the singular terms "a," "an," and "the" are to be construed as covering either the singular or the plural as appropriate to the context.

[0016] Furthermore, all numbers and expressions relating to quantities of ingredients, reaction conditions, and the like used in this specification should be understood as being modified by the term "about," unless otherwise indicated.

[0017] In addition, in this specification, when a part such as a layer or film is described as being formed "on" another element, this covers not only that one element is formed directly "on" the other element, but also that the other element is interposed therebetween.

[0018] In addition, the dimensions of each component in the drawings may be exaggerated for illustrative purposes and are not intended to represent actual dimensions. Furthermore, the same reference numerals refer to the same elements throughout the specification.

[0019] [Wavelength conversion material] A wavelength conversion member according to a first embodiment of the present invention comprises a glass matrix, and a phosphor powder and a spherical silica filler powder dispersed in the glass matrix, When the particle diameters (or particle sizes) showing 10%, 50%, and 90% of the cumulative volume (%) in the particle size distribution measured by laser diffraction are defined as D10, D50, and D90, respectively, the D50 of the spherical silica filler powder is 1.0 to 15.0 μm, and is expressed by the following formula 1:

number

[0020] The wavelength conversion member according to the embodiment of the present invention comprises a glass matrix, and a phosphor powder and a spherical silica filler powder dispersed in the glass matrix. In particular, the spherical silica filler powder has high fluorescence intensity and excellent optical properties because its D50 and SPAN values ​​are within a specific range. In particular, it is possible to suppress the decrease in luminescence intensity over time when irradiated with high-power excitation light.

[0021] In addition, because the spherical silica filler powder has a high melting point of 1400°C or higher, it is chemically stable in terms of heat resistance to the firing temperature during the production of the wavelength conversion member, and is easily adsorbed to the phosphor. This makes it possible to suppress the shrinkage of the wavelength conversion member that occurs during firing during the production of the wavelength conversion member, and to maintain a uniform dispersion of the phosphor particles in the wavelength conversion member.

[0022] Each component of the wavelength conversion member will now be described in detail.

[0023] Glass Matrix The wavelength conversion member according to an embodiment of the present invention includes a glass matrix. The glass matrix may be a base material of the wavelength conversion member obtained by molding and sintering a glass powder as a raw material. The glass matrix may contain a phosphor powder and a spherical silica filler powder dispersed therein.

[0024] Specifically, the glass matrix can be obtained by applying a composition for wavelength conversion members, which contains glass powder, phosphor powder, and spherical silica filler powder, to a substrate in the form of a sheet, and firing the composition. The glass matrix can also be obtained by putting the phosphor powder, spherical silica filler powder, and glass powder into a mold, compressing and molding the mixture, and sintering the mixture at, for example, 450 to 950°C.

[0025] The glass matrix can function as a medium for stably maintaining the phosphor powder and the spherical silica filler powder in a uniformly dispersed state in the glass matrix.

[0026] Referring to FIG. 1, in a wavelength conversion member (100) according to one embodiment of the present invention, phosphor powder (120) and spherical silica filler powder (130) are uniformly dispersed in a glass matrix (110).

[0027] In addition, since the reactivity between the glass powder and the phosphor powder may differ depending on the composition of the glass powder used as the raw material for forming the glass matrix, it is important to select a glass powder composition suitable for the phosphor powder used. For example, if the sintering temperature is increased in the production of the wavelength conversion member, the glass matrix may react with the phosphor, resulting in a decrease in the quantum conversion yield of the wavelength conversion member. Therefore, the composition of the glass powder is important to prevent this.

[0028] According to one embodiment of the present invention, the glass matrix is 2 O 5 , ZnO, SiO 2 , and B. 2 O 3 It is preferable that the main component is

[0029] In particular, the glass matrix can be obtained from a glass powder having a particular composition.

[0030] The glass powder contains 2-10 mole % P based on the total moles of glass powder. 2 O 5 , 30 to 50 mol% ZnO, 10 to 25 mol% SiO 2 and 15 to 25 mol% B 2 O 3 may include:

[0031] Since the glass powder has the above composition, the glass powder can be sufficiently sintered even if the content of the phosphor powder is large, and the decrease in the brightness of the light can be suppressed even when the wavelength conversion member is used for a long period of time. In addition, since the wavelength conversion member has excellent water resistance even in a humid environment, it can achieve excellent light absorption.

[0032] Specifically, P 2 O 5 is a component that forms a glass skeleton and enhances water resistance. 2 O 5 The content may be 2 to 10 mol %, preferably 2 to 6 mol %, based on the total moles of the glass powder.

[0033] P 2 O 5 If the content is less than the above range, vitrification may be difficult, whereas if it exceeds the above range, the softening point (Ts) may become high and weather resistance may decrease.

[0034] ZnO is a component that improves solubility by lowering the melting temperature. The content of ZnO may be 30 to 50 mol %, preferably 30 to 40 mol %, based on the total moles of the glass powder.

[0035] If the ZnO content is less than the above range, the effect of improving the melting property may be small, whereas if it exceeds the above range, the weather resistance may be deteriorated, or the transmittance may be decreased, resulting in a decrease in the emission intensity.

[0036] SiO 2 is a component that forms the glass skeleton. SiO 2 The content may be 10 to 25 mol %, preferably 15 to 25 mol %.

[0037] SiO 2 If the content is less than the above range, the weather resistance and mechanical strength may decrease, whereas if it exceeds the above range, the phosphor powder may be deteriorated by high-temperature firing during the production of the wavelength conversion member.

[0038] B 2 O 3 is a component that forms the glass skeleton. It can lower the melting temperature, improving meltability and increasing light diffusion. 2 O 3 The content may be 15 to 25 mol %, preferably 15 to 20 mol %, based on the total number of moles of the glass powder.

[0039] B 2 O 3 If the content is less than the above range, the above effects may be difficult to obtain, whereas if the content exceeds the above range, chemical durability may decrease.

[0040] According to one embodiment of the present invention, the glass powder contains 1 to 10 mol % Al. 2 O 3 , 0.1 to 7 mol% SnO 2 , 1 to 5 mol% SnO 2, 1 to 5 mol% BaO, 0.1 to 5 mol% SrO, 1 to 5 mol% CaO, 1 to 5 mol% Li 2 O, 1 to 7 mol% Na 2 O, and 1 to 5 mol% K 2 O may further comprise at least one selected from the group consisting of

[0041] Al 2 O 3 Al is a component that enhances chemical durability. 2 O 3 The content may be 1 to 10 mol %, preferably 2 to 6 mol %, based on the total moles of the glass powder.

[0042] Al 2 O 3 If the content of Al is less than the above range, the effect of improving chemical durability may be reduced. 2 O 3 If the content exceeds the above range, the meltability of the glass tends to decrease.

[0043] SnO 2 is a component that can lower thermal property temperatures such as the glass transition temperature, yield point, and softening point (Ts). 2 The content may be 0.1 to 7 mol %, more preferably 0.2 to 6 mol %, based on the total moles of the glass powder.

[0044] SnO 2 If the content of SnO is less than the above range, the effect of lowering the thermophysical temperature may be small. 2 If the content of exceeds the above range, devitrification substances (especially tetravalent tin substances) due to Sn tend to precipitate in the glass during glass melting, resulting in a decrease in transmittance. As a result, it becomes difficult to obtain a wavelength conversion member with high luminous efficiency, and vitrification by melt separation may become difficult.

[0045] BaO is a component that lowers the melting temperature and improves the melting property, and also has the effect of promoting phase separation of the glass and suppressing the reaction with the phosphor powder.

[0046] The content of BaO may be 1 to 5 mol%, preferably 1 to 4 mol%. If the content of BaO is less than the above range, the effect of improving the solubility may be reduced. If the content of BaO exceeds the above range, the chemical durability may decrease and the tendency of the glass to undergo phase separation may become too great, so that even a slight change in the heat treatment temperature may cause a large change in the phase separation state. This may cause an imbalance in the diffusion of light among a large number of wavelength conversion members.

[0047] SrO is a component that lowers the melting temperature and improves the melting property. It also has the effect of promoting phase separation of glass and suppressing reaction with phosphor powder.

[0048] The content of SrO may be 0.1 to 5 mol%, preferably 0.1 to 4 mol%. If the content of SrO is less than the above range, the effect of improving the melting property may be small. If the content of SrO exceeds the above range, the chemical durability decreases and the tendency of the glass to separate into phases becomes too large, so that even a slight change in the heat treatment temperature may cause a large change in the phase separation state. For this reason, the light diffusion is likely to vary among a large number of wavelength conversion members.

[0049] CaO is a component that lowers the melting temperature and improves the meltability. It also has the effect of promoting phase separation of the glass and suppressing the reaction with the phosphor powder.

[0050] The CaO content may be 1 to 5 mol%, preferably 1 to 4 mol%. If the CaO content is less than the above range, the effect of improving the solubility may be small. If the CaO content exceeds the above range, the chemical durability decreases and the tendency of the glass to separate into phases becomes too great, so that even a slight change in the heat treatment temperature may cause a large change in the phase separation state. For this reason, the light diffusion is likely to vary among a large number of wavelength conversion members.

[0051] Li 2 O is a component that lowers the softening point.2 The O content is preferably 1 to 5 mol %, and more preferably 2 to 5 mol %, based on the total number of moles of the glass powder.

[0052] Li 2 If the O content is less than the above range, the above effects may be reduced. 2 If the O content exceeds the above range, the chemical durability may decrease, or the glass may have an excessive tendency to undergo phase separation, resulting in increased light scattering loss. In addition, problems may occur such as a decrease in weather resistance and a decrease in luminous intensity over time due to irradiation with light from a light-emitting diode (LED) or laser diode (LD).

[0053] Na 2 O is a component that lowers the softening point. 2 The O content is preferably 1 to 7 mol %, and more preferably 2 to 6 mol %, based on the total number of moles of the glass powder.

[0054] Na 2 If the O content is less than the above range, the above effects may be reduced. 2 If the O content exceeds the above range, the chemical durability may decrease, or the glass may have an excessive tendency to separate into phases, resulting in increased light scattering loss. In addition, problems may occur such as a decrease in weather resistance and a decrease in luminous intensity over time due to light irradiation from an LED or LD.

[0055] K 2 O is a component that lowers the softening point. 2 The O content is preferably 1 to 5 mol %, and more preferably 2 to 5 mol %, based on the total number of moles of the glass powder.

[0056] K 2 If the O content is less than the above range, the above effects may be reduced. 2If the O content exceeds the above range, the chemical durability may decrease, or the glass may have an excessive tendency to separate into phases, resulting in increased light scattering loss. In addition, problems may occur such as a decrease in weather resistance and a decrease in luminous intensity over time due to light irradiation from an LED or LD.

[0057] Specifically, the glass powder may contain 0.1 to 7 mol %, for example 0.2 to 6 mol % SnO based on the total moles of the glass powder. 2 and 1 to 10 mol %, for example 2 to 6 mol % Al. 2 O 3 It may further include.

[0058] The glass powder may further comprise 1-5 mol % BaO, 0.1-5 mol % SrO, and 1-5 mol % CaO, based on the total moles of the glass powder.

[0059] The glass powder contains 1-5 mole % K based on the total moles of glass powder. 2 O, 1 to 5 mol% Na 2 O, and 1 to 5 mol% Li 2 It may further contain O.

[0060] Alternatively, the glass powder may contain, as the alkali metal oxide, Na 2 O and K 2 O, Na 2 O and Li 2 O, or Li 2 O and K 2 It may further contain O. When the glass powder contains the above components in the above combination, it is desirable to appropriately adjust the total content of these components within the range of 2 to 15 mol %, preferably 3 to 10 mol %.

[0061] The average particle size (D50) of the glass powder may be from 2 to 15 μm, preferably from 5 to 15 μm.

[0062] If the average particle size (D50) of the glass powder is less than the above range, the amount of bubbles generated during firing increases, and bubbles may remain in the wavelength conversion member. The porosity of the wavelength conversion member is preferably 5% or less, 3% or less, and particularly 1% or less. If the porosity exceeds the above range, the optical properties may deteriorate. Furthermore, if the wavelength conversion member contains a large number of bubbles, light scattering may become excessive, and the fluorescence intensity may decrease due to scattering loss.

[0063] In addition, moisture may easily penetrate into the wavelength conversion member, which may reduce the chemical durability. If the average particle size (D50) of the glass powder exceeds the above range, it may be difficult to uniformly disperse the phosphor powder in the wavelength conversion member. As a result, the fluorescence intensity of the wavelength conversion member may decrease, or chromaticity deviation may occur.

[0064] The refractive index of the glass matrix may be 1.44 to 1.89. Specifically, the refractive index of the glass matrix is ​​preferably 1.57 to 1.85, and more preferably 1.60 to 1.84.

[0065] On the other hand, the softening point (Ts) of the glass matrix may be 550 to 850°C.

[0066] Specifically, the softening point (Ts) of the glass matrix is ​​preferably from 550 to 630°C, and more preferably from 550 to 600°C.

[0067] If the softening point (Ts) of the glass matrix is ​​too low, the mechanical strength and chemical durability of the wavelength conversion member may decrease. In addition, since the thermal resistance of the glass matrix itself is low, the glass matrix may absorb the heat generated by the phosphor, melt, and cause a softening deformation in which the shape changes. On the other hand, if the softening point (Ts) of the glass matrix is ​​too high, the phosphor powder may deteriorate during sintering, causing a decrease in the luminescence intensity of the wavelength conversion member. In addition, the softening point (Ts) of the glass matrix is ​​preferably 550°C or higher from the viewpoint of increasing the chemical stability and mechanical strength of the wavelength conversion member. Examples of such glasses include borosilicate glass, P 2 O 5 -ZnO-SiO 2 -B 2 O 3 Glasses based on these compounds are also useful.

[0068] Phosphor Powder According to an embodiment of the present invention, the phosphor powder can be uniformly dispersed in the glass matrix. When the phosphor powder is uniformly dispersed in the glass matrix, a wavelength conversion member having excellent heat resistance can be provided.

[0069] The phosphor powder may include a phosphor powder that emits fluorescence with a wavelength longer than that of the excitation light when ultraviolet or visible excitation light is incident. For example, when visible excitation light is incident and a phosphor powder that emits fluorescence of a complementary color of the excitation light is used, the transmitted excitation light and the fluorescence of the phosphor powder are mixed to generate white light. Therefore, a white LED can be easily manufactured. Specifically, when the visible excitation light has a dominant wavelength of 430 to 490 nm and the fluorescence of the phosphor powder has a dominant wavelength of 530 to 590 nm, it can be advantageous to provide white light.

[0070] The average particle size (D50) of the phosphor powder may be 3 to 30 μm, preferably 3 to 30 μm. If the average particle size (D50) of the phosphor powder is less than the above range, the phosphor powder particles may easily aggregate, resulting in a decrease in luminous intensity. If the average particle size (D50) of the phosphor powder exceeds the above range, the efficiency of the wavelength conversion member may decrease or the color shift may become large, which is not preferable.

[0071] The type of phosphor powder is not particularly limited. For example, nitride phosphor powder, oxynitride phosphor powder, oxide phosphor powder (including garnet phosphor powder such as YAG phosphor powder), sulfide phosphor powder, oxysulfide phosphor powder, halide phosphor powder (such as fluoride and chloride), and aluminum oxychloride phosphor can be mentioned. Among the above phosphor powders, nitride phosphor powder, oxynitride phosphor powder, and oxide phosphor powder have high heat resistance and are not easily deteriorated during firing, and are particularly suitable as phosphor powders used in wavelength conversion members for white LED devices.

[0072] From the viewpoint of increasing the quantum conversion efficiency, the phosphor powder is preferably an oxide phosphor powder or a chloroaluminate phosphor powder.

[0073] The oxide phosphor or aluminochloride phosphor may comprise at least one phosphor powder selected from the group consisting of yttrium-aluminum-garnet (YAG)-based, lutetium-aluminum-garnet (LuAG)-based, nitride-based, sulfide-based and silicate-based materials.

[0074] The phosphor powder may be a phosphor powder having an emission wavelength range in the visible wavelength range, for example, from 380 nm to 780 nm.

[0075] Specifically, the phosphor powder may include at least one selected from blue, green, red, and yellow luminescent particles, where the blue, green, red, and yellow luminescent particles refer to particles that emit blue, green, red, and yellow fluorescence, respectively.

[0076] The blue light-emitting particles may include phosphor powder having an emission wavelength range of 440 nm to 480 nm. The green light-emitting particles may include phosphor powder having an emission wavelength range of 500 nm to 540 nm. The yellow light-emitting particles may include phosphor powder having an emission wavelength range of more than 540 nm to 595 nm. The red light-emitting particles may include phosphor powder having an emission wavelength range of 660 nm to 700 nm.

[0077] Specifically, when irradiated with ultraviolet to near ultraviolet excitation light with a wavelength of 300 nm to 440 nm, the blue light-emitting particles are (Sr,Ba)MgAl 10 O 17 :EU 2+ , (Sr,Ba) 3 MgSi 2 O 8 :EU 2+ may be also possible.

[0078] When irradiated with ultraviolet to near ultraviolet excitation light with wavelengths of 300 nm to 440 nm, the green luminescent particles are SrAl 2 O 4 :EU 2+ ;SrBaSiO 4 :EU 2+ ;(Y,Lu) 3 (Al,Gd) 5 O 12 :Ce 3+ ;SrSiON:Eu 2+ ;BaMgAl 10 O 17 :EU 2+ ,Mn 2+ ;Ba 2 MgSi 2 O 7 EU 2+ ;Ba 2 SiO 4 :EU 2+ ;Ba 2 Li 2 S 2 O 7 :EU 2+ ;BaAl 2 O 4 :EU 2+ When irradiated with blue excitation light having a wavelength of 440 nm to 480 nm, the green light-emitting particles may be SrAl2 O 4 :EU 2+ ;SrBaSiO 4 :EU 2+ ;(Y,Lu) 3 (Al,Gd) 5 O 12 :Ce 3+ ;SrSiON:Eu 2+ ;β-SiAlON:Eu 2+ may be also possible.

[0079] When irradiated with ultraviolet to near-ultraviolet excitation light with wavelengths of 300 nm to 440 nm, the yellow light-emitting particles are La 3 S 6 N 11 :Ce 3+ When irradiated with blue excitation light having a wavelength of 440 nm to 480 nm, the yellow light-emitting particles may be (Y, Lu) 3 (Al,Gd) 5 O 12 :Ce 3+ ;Sr 2 SiO 4 :EU 2+ may be also possible.

[0080] When irradiated with ultraviolet to near ultraviolet excitation light with wavelengths of 300 nm to 440 nm, the red light-emitting particles are CaGa 2 S 4 :Mn 2+ ;MgSr 3 S 2 O 8 :EU 2+ ,Mn 2+ ;Ca 2 MgSi 2 O 7 :EU 2+ ,Mn 2+ When irradiating with blue excitation light having a wavelength of 440 nm to 480 nm, the red light emitting particles may be CaAlSiN 3 :EU 2+ ;CaSiN 3 :EU 2+ ;(Ca,Sr) 2 S 5 N 8 :EU 2+ ;α-SiAlON:Eu 2+may be also possible.

[0081] According to an embodiment of the present invention, various phosphor powders may be mixed and used depending on the excitation light and emission wavelength. For example, when generating white light by irradiating excitation light in the ultraviolet region, phosphor powders containing blue, green, yellow, or red light emitting particles may be used.

[0082] The refractive index of the phosphor powder may be 1.5 to 2.4.

[0083] In addition, in the wavelength conversion member of the present invention, the difference in refractive index between the glass matrix and the phosphor powder may be, for example, less than 0.05, preferably less than 0.03. When the difference in refractive index between the glass matrix and the phosphor powder is small, suitable scattering and light diffusion are achieved, which is considered to be more advantageous for achieving the desired effects in the present invention.

[0084] According to one embodiment of the present invention, the content of the phosphor powder in the wavelength conversion member may be 5 to 50% by weight, preferably 10 to 40% by weight, and more preferably 10 to 30% by weight of the entire phosphor, based on the total weight of the glass matrix, the spherical silica filler powder, and the phosphor powder.

[0085] If the content of the phosphor powder is too low, the amount of light emitted will be insufficient, making it difficult to obtain the desired white light. If the content of the phosphor powder is too high, sintering will be difficult, and the excitation light will not be sufficiently irradiated to the entire phosphor powder, which may reduce the fluorescence intensity. In addition, voids will easily form inside the wavelength conversion member, making it difficult to obtain a dense structure.

[0086] Spherical silica filler powder According to one embodiment of the present invention, the wavelength converting member comprises a spherical silica filler powder.

[0087] In a wavelength conversion member containing spherical silica filler powder, both the glass matrix and the spherical silica filler powder are made of glass, and therefore, the occurrence of non-uniform layers or voids at the interface between them can be minimized.

[0088] The spherical silica filler powder can be uniformly dispersed in the glass matrix. When the spherical silica filler powder is uniformly dispersed in the glass matrix, the heat resistance is improved, and the decrease in the fluorescence intensity and the occurrence of the color shift can be minimized.

[0089] The wavelength conversion member of the present invention is characterized by containing a spherical silica filler powder and having a particle size distribution in a specific range, ie, a D50 of 1.0 to 15.0 μm and a SPAN value of 1.0 to 5.0.

[0090] Specifically, the D50 of the spherical silica filler powder may be 1.0 to 15.0 μm, preferably 1.2 to 13.2 μm, and more preferably 2.0 to 6.0 μm. If the D50 of the spherical silica filler powder is less than the above range, the spherical silica filler powder may aggregate, resulting in a decrease in the light transmittance of the wavelength conversion member. On the other hand, if the D50 of the spherical silica filler powder exceeds the above range, the distribution of the spherical silica filler powder in the wavelength conversion member may become non-uniform, resulting in a decrease in the fluorescence intensity of the wavelength conversion member or a large chromaticity deviation. In addition, the wavelength conversion member may shrink during firing. On the other hand, if the D50 of the spherical silica filler powder satisfies the above range, the distance between the spherical silica filler particles or between the spherical silica filler powder and the phosphor powder is shortened, and heat can be effectively dissipated to the outside.

[0091] The SPAN value of the spherical silica filler powder may be 1.0 to 5.0, preferably 1.0 to 4.5, and more preferably 1.0 to 3.0.

[0092] The SPAN value is an index that indicates the particle size distribution of the spherical silica filler powder. Specifically, the SPAN value is an index that indicates the particle size and amount ratio of silica powder that exists mainly as fine particles in the spherical silica powder to silica powder that exists as slightly larger particles.

[0093] When the SPAN value satisfies the above range, a decrease in the fluorescence intensity or an imbalance in chromaticity of the wavelength conversion member is suitably suppressed.

[0094] If the PAN value is less than the above range, the spherical silica filler powder is likely to re-aggregate and form large aggregates when the wavelength conversion member is produced. In such a case, it is undesirable because there is a possibility that a large amount of scattering occurs beyond the effective range to the extent that light cannot be transmitted. On the other hand, if the SPAN value of the spherical silica filler powder exceeds the above range, the ratio of the fine silica filler powder to the coarse silica filler powder becomes relatively large, making it difficult to make a paste.

[0095] When the SPAN value satisfies the above range, a symmetrical particle size distribution can be obtained, or an asymmetrical particle size distribution with a short base on the coarse side and a long base on the fine side can be obtained.

[0096] In the present invention, the particle size of the spherical silica filler powder was measured using an S3500 device manufactured by Microtrea Corporation. The analytical values ​​D10, D50, and D90 respectively indicate the particle size (D10) when the cumulative volume concentration (%) is 10%, the particle size (D50) when the cumulative volume concentration (%) is 50%, and the particle size (D90) when the cumulative volume concentration (%) is 90% in particle size distribution measurement by laser light diffraction method. The SPAN value can be calculated using the above formula 1.

[0097] Furthermore, the D90 / D10 (DSPAN) of the spherical silica filler powder may be 1.5-15, preferably 1.5-13, and more preferably 1.5-10.

[0098] The D90 / D10 (DSPAN) value is an index that indicates the ratio of particle size distribution to particle size of the spherical silica filler powder. Specifically, the D90 / D10 (DSPAN) value is an index that indicates the ratio of particle size and amount of silica powder that exists mainly as fine particles in the spherical silica powder to silica powder that exists as slightly larger particles.

[0099] When the D90 / D10(DSPAN) value is within the upper limit of the above range, the particle size distribution curve of the spherical silica filler powder will show a sharp shape. When the D90 / D10(DSPAN) value of the spherical silica filler powder is within the above range, the shrinkage of the wavelength conversion member during sintering can be suppressed, and the uniform dispersion of the phosphor particles in the wavelength conversion member can be suitably maintained.

[0100] The specific surface area (Brunauer-Emmett-Teller; BET) of spherical silica filler powder is 1.0 to 6.5 m 2 / g, preferably 2.0 to 5.0 m 2 / g, more preferably 2.0 to 4.0m 2 / g.

[0101] If the specific surface area of ​​the spherical silica filler powder is less than the above range, the number of silica filler powder aggregates increases, and the light transmittance of the wavelength conversion member may decrease. On the other hand, if the specific surface area of ​​the spherical silica filler powder exceeds the above range, the dispersibility of the spherical silica filler powder in the wavelength conversion member may decrease, and the fluorescence intensity of the wavelength conversion member may decrease or the chromaticity deviation may increase.

[0102] The specific surface area can be measured by the BET method using nitrogen adsorption, for example, using a commonly used specific surface area measuring device (such as Macsorb HM (Model 1210) manufactured by MOUNTECH or Belsorp-mini II manufactured by Microtrac BEL).

[0103] Since the spherical silica filler powder has a spherical shape, it exhibits large light scattering (scattering of excitation light), and is therefore advantageous for obtaining a wavelength conversion member capable of emitting uniform, high-intensity fluorescent light.

[0104] On the other hand, the average sphericity of the spherical silica filler powder is preferably 2.0 or less, and more preferably 1.5 or less.

[0105] In the present invention, "sphericity" refers to the "long axis diameter (L max ) / Short axis diameter (L min )".

[0106] Referring to FIG. 2, the major axis diameter (L max ) is the length of the longest straight line (L max ) can be referred to as the minor axis diameter (L min ) is the length of the shortest straight line (L min ) can be used.

[0107] According to one embodiment of the present invention, the spherical silica filler powder may contain a certain number of particles having a relatively small particle size. In this case, if the spherical silica filler powder is not completely spherical, the silica filler powder having a relatively small particle size may enter the gaps between the particles and fill the gaps. In consideration of the above, the average sphericity of the spherical silica filler powder is preferably 1.1 to 1.5.

[0108] On the other hand, the refractive index of the spherical silica filler powder may be 1.44 to 1.47.

[0109] The difference in refractive index between the glass matrix and the spherical silica filler powder may be 0.01 to 0.52, preferably 0.12 to 0.50, and more preferably 0.33 to 0.40.

[0110] If the difference in refractive index between the glass matrix and the spherical silica filler powder is too large, the light reflectance at the interface between the glass matrix and the spherical silica filler powder increases, causing excessive light scattering and reducing the light efficiency. It may become difficult for the excitation light to be irradiated onto the phosphor powder in the wavelength conversion member, causing a reduction in the fluorescence intensity. If the difference in refractive index between the glass matrix and the spherical silica filler powder is too small, sufficient light scattering cannot be obtained, which reduces the luminous intensity and may make it difficult to achieve the desired effect of the present invention.

[0111] On the other hand, the softening point (Ts) of the spherical silica filler powder is preferably 500°C or more higher than the softening point (Ts) of the glass matrix. In this case, it is possible to prevent the silica powder from softening and flowing during the production of the wavelength conversion member, which would cause a decrease in light diffusibility. Specifically, the softening point (Ts) of the spherical silica filler powder is 1400 to 1700°C, preferably 1400 to 1600°C.

[0112] The content of the spherical silica filler powder may be 0.5 to 50% by weight based on the total weight of the glass matrix, the spherical silica filler powder, and the phosphor powder. Specifically, the content of the spherical silica filler powder is preferably 0.5 to 30% by weight, more preferably 1 to 20% by weight, based on the total weight of the glass matrix, the spherical silica filler powder, and the phosphor powder. If the content of the spherical silica filler powder is less than the above range, the effect of the filler is not fully exerted. If the content of the spherical silica filler powder exceeds the above range, the light scattering becomes excessive, the loss increases, and the light efficiency may decrease.

[0113] Furthermore, when the difference in refractive index between the phosphor powder and the glass matrix is ​​relatively large, light scattering is likely to occur, and therefore, even if spherical silica filler powder is added, the effect of the filler may not be obtained easily.

[0114] Therefore, it is desirable to appropriately determine the content of the silica powder in consideration of the difference in refractive index between the phosphor powder and the glass matrix.

[0115] According to one embodiment of the present invention, the content of the glass powder and the spherical silica filler powder forming the glass matrix can be changed according to the content of the phosphor powder.

[0116] Specifically, the weight ratio (X:Y) of the content of the mixture of glass powder and spherical silica filler powder (X) to the phosphor powder (Y) may be 60-95:5-40, preferably 70-95:5-30. If the mixture of glass powder and spherical silica filler powder (X) is less than the above range, the sinterability deteriorates, the transmittance of the wavelength conversion member decreases, and the desired white light cannot be obtained.

[0117] When the weight ratio (X:Y) of the content (X) of the mixture of glass powder and spherical silica filler powder to the phosphor powder (Y) satisfies the above range, the light transmittance from the light source and the conversion amount of the phosphor powder can be controlled in a well-balanced manner, and the dimensional shrinkage of the wavelength conversion member can be suppressed during production of the wavelength conversion member, thereby minimizing the occurrence of spots of light conversion chromaticity.

[0118] According to one embodiment of the present invention, the weight ratio of the phosphor powder to the spherical silica filler powder may be 1:0.1-5.

[0119] Characteristics of wavelength conversion materials The thickness of the wavelength conversion member according to one embodiment of the present invention may be 100 to 800 μm, preferably 150 to 500 μm. If the thickness of the wavelength conversion member is equal to or greater than the lower limit of the above range, the wavelength conversion member is easy to handle and is prevented from cracking when it is cut to a desired size. If the thickness of the wavelength conversion member is equal to or less than the upper limit of the above range, the amount of light flux passing through the wavelength conversion member can be kept high. If the thickness of the wavelength conversion member is too thick, exceeding the above range, the luminous efficiency of the phosphor may decrease.

[0120] The light transmittance of the wavelength conversion member may be 70 to 95%. Specifically, the light transmittance of the wavelength conversion member may be 72 to 92%, or 72.2 to 85%.

[0121] The luminous flux (Φv) of the wavelength conversion member may be 66 to 80 lm. Specifically, the luminous flux (Φv) of the wavelength conversion member may be 73 to 80 lm or 74 to 80 lm.

[0122] The converted light flux of the wavelength conversion member may be 98% to 105%. Specifically, the converted light flux of the wavelength conversion member may be 98% to 103%, or 100% to 103%.

[0123] The luminous flux and converted luminous flux can be measured from the chromaticity distribution using an integrating sphere measuring device (LMS-200, manufactured by J&C Tech.) and an excitation light source of 445 nm.

[0124] Furthermore, the wavelength conversion member preferably has a parallel light (straight line) transmittance of 20% or less, and more preferably 10% or less, measured in accordance with JIS K 7105. If the parallel light transmittance is too high, the light will propagate too much, which may result in a decrease in fluorescence intensity and color shift.

[0125] Furthermore, the wavelength conversion member may have a haze of 70% or more, preferably 75% or more, measured in accordance with JIS K7105.

[0126] [Preparation process of wavelength conversion material] The present invention provides a method for producing a wavelength conversion member.

[0127] Referring to FIG. 3, a method for producing a wavelength conversion member according to one embodiment of the present invention may include a first step (S110) of obtaining a composition for wavelength conversion members containing glass powder, phosphor powder, and spherical silica filler powder, a second step (S120) of applying the composition for wavelength conversion members onto a substrate to obtain a green sheet for wavelength conversion members, and a third step (S130) of firing the green sheet for wavelength conversion members.

[0128] Specifically, the first step (S110) includes obtaining a composition for a wavelength conversion member, which contains a glass powder, a phosphor powder, and a spherical silica filler powder.

[0129] Specifically, a composition containing a glass powder capable of forming a glass matrix, a phosphor powder, and a spherical silica filler powder can be prepared. The types and contents of the glass powder, phosphor powder, and spherical silica filler powder are as described above.

[0130] According to one embodiment of the present invention, the content of each component in the composition for wavelength conversion member can be considered to be the same as the content of each component contained in the wavelength conversion member after firing.

[0131] The composition for wavelength conversion members may further contain a binder resin and a solvent.

[0132] The binder resin may include at least one selected from the group consisting of polyvinyl butyral (PVB), polyvinyl alcohol (PVA), and polyvinyl acetate (PVAc). Specifically, the binder resin may include polyvinyl butyral (PVB) or polyvinyl alcohol (PVA).

[0133] The weight average molecular weight of the binder resin may be 1,000 to 70,000 g / mol. Specifically, the weight average molecular weight of the binder resin may be 20,000 to 60,000 g / mol.

[0134] The solvent may have a low boiling point in order to rapidly produce the green sheet. Specifically, the boiling point of the solvent may be 30 to 150° C. More specifically, the boiling point of the solvent may be 60 to 130° C.

[0135] The solvent may also comprise at least one selected from the group consisting of toluene, ethanol, butanol, acetone, and methanol. Specifically, the solvent may comprise at least one selected from the group consisting of toluene, ethanol, and butanol. For example, the solvent may comprise toluene, ethanol, and butanol.

[0136] The content of the solvent may be appropriately selected depending on the properties of the composition and the drying conditions. Specifically, the solvent may be contained in an amount of 30 to 50% by weight based on the total weight of the composition for wavelength conversion member.

[0137] The composition for wavelength conversion members may further contain a plasticizer. The plasticizer may contain at least one selected from the group consisting of DOP (dioctyl phthalate), DOA (dioctyl adipate), and TCP (tricresyl phosphate). Specifically, the plasticizer may contain DOP (dioctyl phthalate) or DOA (dioctyl adipate).

[0138] The plasticizer may be contained in an amount of 10 to 200 parts by weight based on 100 parts by weight of the binder resin. Specifically, the plasticizer may be contained in an amount of 30 to 90 parts by weight based on 100 parts by weight of the binder resin.

[0139] The composition for wavelength conversion members can be prepared by mixing a solvent and a binder resin, removing air bubbles to obtain a binder solution, and then mixing the binder solution, glass powder, phosphor powder, spherical silica filler powder, and a plasticizer. In the present invention, by using a solvent having a low boiling point, the binder resin and the solvent can be mixed at room temperature when preparing the composition for wavelength conversion members.

[0140] The second step (S120) includes applying the composition for the wavelength conversion member onto a substrate to obtain a green sheet for the wavelength conversion member.

[0141] Specifically, the composition for wavelength conversion member obtained in the first step is applied onto a substrate. Here, the application may be performed by a tape casting method or a doctor blade, or the like.

[0142] The substrate may be a polyester substrate, for example, a resin film such as polyethylene terephthalate (PET).

[0143] According to one embodiment of the present invention, the green sheet for wavelength conversion member may be one sheet, or may be a laminate of multiple green sheets for wavelength conversion member produced by casting and compressing them. In this case, the number of layers of the green sheets for wavelength conversion member is not particularly limited. For example, the green sheets for wavelength conversion member may be laminated so that the thickness of the green sheet for wavelength conversion member when compressed is 50 to 1500 μm.

[0144] The compression may be performed at a pressure of 1 to 100 MPa. Specifically, the compression may be performed at a pressure of 2 to 50 MPa.

[0145] The third step (S130) includes firing the green sheet for the wavelength conversion member.

[0146] The firing temperature is preferably within the range of the softening point of the glass matrix ±100° C., particularly within the range of the softening point of the glass matrix ±50° C. If the firing temperature is too low, it may be difficult to fuse the layers, the glass powder may not be sufficiently fired, or the mechanical strength of the wavelength conversion member may be reduced. On the other hand, if the firing temperature is too high, the luminescence intensity of the wavelength conversion member may be reduced.

[0147] The firing may be carried out at 450 to 950° C. for 10 minutes to 72 hours. Specifically, the firing may be carried out at 600 to 800° C. for 10 minutes to 52 hours.

[0148] In each of the above manufacturing processes, degreasing to remove organic substances may be performed before firing, i.e., after compressing the green sheet for wavelength conversion member and before firing. In addition, when multiple green sheets for wavelength conversion member are included, each layer may be appropriately heated and pressed to increase the adhesion of each layer when stacking them.

[0149] The fabrication process may also optionally comprise further processing steps after sintering, such as grinding, polishing, and re-pressing.

[0150] Light Emitting Device One aspect of the present invention provides a light-emitting device including the wavelength conversion member described above and a light source that irradiates the wavelength conversion member with excitation light.

[0151] Specifically, the wavelength conversion member may be used as a light emitting device together with a light source that irradiates excitation light to the phosphor powder. As the light source, a semiconductor light emitting device such as a light emitting diode (LED) and a laser diode (LD) may be used. A plurality of semiconductor light emitting elements may be used.

[0152] The light emitting device may be arranged such that the wavelength conversion member is in direct contact with the semiconductor light emitting device. For example, the light emitting device may have a structure in which the semiconductor light emitting device and the wavelength conversion member are sequentially stacked. Alternatively, the semiconductor light emitting device may be arranged so as to be surrounded by the wavelength conversion member, or the wavelength conversion member may be arranged so as to be surrounded by the semiconductor light emitting device.

[0153] Furthermore, the semiconductor light emitting device and the wavelength converting member may be spaced apart from each other.

[0154] Modes of the Invention The present invention will be described in more detail below with reference to examples. However, these examples are provided for the purpose of illustrating the present invention, and the scope of the present invention is not limited to these examples.

[0155] Preparation Example 1: Preparation of glass powder Glass was prepared by mixing the components so as to obtain the composition shown in Table 1 below and melting the mixture at 1200° C. The prepared glass was pulverized to produce glass powder having an average particle size of 5.9 μm.

[0156] [Table 1]

[0157] Example 1: Preparation of wavelength conversion member 1-1. Preparation of composition of wavelength conversion member As shown in Table 2 below, 80% by weight of the glass powder of Preparation Example 1, 10% by weight of YAG phosphor powder (average particle size (D50): 25 μm, manufacturer: Ohshu Electronic Materials, product name: DLP-Y62-25), and 10% by weight of spherical silica filler powder (DENKA / FB-7SDX) were mixed with a binder solution and plasticizer in a ratio of 85:15 to prepare a composition for wavelength conversion members.

[0158] Here, the binder solution was prepared by adding 27 g of polyvinyl butyral (PVB, weight average molecular weight: 50,000 g / mol) to 81 g of solvent (a mixture of toluene and butanol in a volume ratio of 3:2) and dissolving at room temperature for 1 h, and the plasticizer was a phthalate ester-based plasticizer.

[0159] 1-2. Preparation of green sheet for forming wavelength conversion member The composition for wavelength conversion members prepared in step 1-1 above was applied onto a PET film by tape casting, and the resulting green sheet for wavelength conversion members having a thickness of 50 μm was obtained by forming a sheet. 21 of the above green sheets were stacked and pressed at a pressure of 14 MPa to obtain a green sheet for wavelength conversion members.

[0160] 1-3. Firing of green sheets for wavelength conversion materials The green sheet for wavelength conversion member prepared in step 1-2 above was fired at 600° C. for 12 hours to obtain a wavelength conversion member.

[0161] Examples 2 to 7 A wavelength conversion member was prepared in the same manner as in Example 1, except that in step 1-1 of Example 1, spherical silica filler powders with different particle size distributions were used and the contents of glass powder, spherical silica filler powder, and phosphor powder were adjusted as shown in Table 2 below.

[0162] Comparative Example 1 A wavelength conversion member was produced in the same manner as in Example 1, except that in step 1-1 of Example 1, no spherical silica filler powder was used and the glass powder content was changed to 90% by weight as shown in Table 2 below.

[0163] Comparative Example 2 As shown in Table 2 below, a wavelength conversion member was prepared in the same manner as in Example 1, except that in step 1-1 of Example 1, a rectangular columnar silica filler powder (Amotec, abp-05) was used instead of the spherical silica filler powder.

[0164] Comparative Example 3 As shown in Table 2 below, a wavelength conversion member was prepared in the same manner as in Example 1, except that in step 1-1 of Example 1, a spherical fumed silica filler powder having a different particle size distribution (Aerosil R-202, manufactured by Evonik) was used instead of the spherical silica filler powder.

[0165] Comparative Examples 4 to 5 As shown in Table 2 below, in step 1-1 of Example 1, spherical silica filler powders having SPAN values ​​of 1.4 and 5.4, respectively, and different particle size distributions were used, but the wavelength conversion member was prepared in the same manner as in Example 1.

[0166] Test Example The physical properties of each component used in the Examples and Comparative Examples, or each wavelength conversion member produced in the Examples and Comparative Examples, were evaluated by the following methods. The results are shown in Tables 2 and 3.

[0167] (1) Softening point (Ts) The softening point (softening temperature) was measured using a thermal analyzer (SDT:Q600, TA Instruments, USA) at a temperature increase rate of 10°C / min from room temperature to 1000°C.

[0168] (2) Refractive index The refractive index was measured using Professional Gemstone Refractometers (Kruess model ER601 LED, Germany). For the measurement, the sample was processed to a thickness of 1 mm (1T), and a certain amount of the refractive solution was applied to the measurement position of the sample so that it was in close contact with the measurement site.

[0169] (3) Particle size Particle size was measured using an S3500 device manufactured by Microtrea Corp. The analytical values ​​D10, D50, and D90 indicate the particle size (D10) when the cumulative volume concentration (%) is 10%, the particle size (D50) when the cumulative volume concentration (%) is 50%, and the particle size (D90) when the cumulative volume concentration (%) is 90%, respectively, in particle size distribution measurement by laser light diffraction method.

[0170] (4) BET The specific surface area of ​​the silica filler powder used in the examples and comparative examples was measured using a Mountec Maxsorb HM (Model 1210) with a mixture of nitrogen and helium gas (N 2 The measurements were performed using a single-point BET method under a flow of 0.1% NaCl, 0.2% NaCl, and 0.3% He.

[0171] (5) Light transmittance (%) The transmittance of light with a reference wavelength of 550 nm was measured using a PerkinElmer UV / Visible spectrophotometer (Lambda35, USA). The light transmittance in the absence of a sample was 100%.

[0172] (6) Chromaticity distribution (Cx, Cy, luminous flux (Φv, lumen (lm)), and equivalent luminous flux (%) The chromaticity distribution was measured using an integrating sphere measuring device (LMS-200, manufactured by J&C Tech.) by placing a wavelength conversion member on a 445 nm excitation light source.

[0173] [Table 2]

[0174] [Table 3]

[0175] As can be seen from Table 3 above, in the wavelength conversion members of Examples 1 to 7 containing phosphor powder and spherical silica filler powder dispersed in a glass matrix, the D50 of the spherical silica filler powder was 1.23 to 13.2, the SPAN value was 1.1 to 4.5, and the optical properties such as light transmittance, luminous flux, and converted luminous flux were excellent overall.

[0176] Specifically, the wavelength conversion members of Examples 1 to 7 had excellent light transmittance of 72.3 to 72.7%, luminous flux of 73.6 to 78.6 lm, and converted luminous flux of 100.3 to 102.2%.

[0177] In contrast, the wavelength conversion member of Comparative Example 1 which did not contain silica filler powder, the wavelength conversion member of Comparative Example 2 which contained prismatic silica filler powder, and the wavelength conversion members of Comparative Examples 3 to 5 in which either the D50 value or the SPAN value of the spherical silica filler powder was outside the range of the present invention were all inferior in optical properties such as light transmittance, luminous flux, and converted luminous flux compared to the wavelength conversion members of Examples 1 to 7. [Explanation of symbols]

[0178] [Drawing symbol] 100: Wavelength conversion material 110: Glass matrix 120: Phosphor powder 130: Spherical silica filler powder L max :Major axis diameter L min : minor axis diameter

Claims

1. A glass matrix, and a phosphor powder and a spherical silica filler powder dispersed in the glass matrix, When particle sizes indicating 10%, 50% and 90% of the cumulative volume (%) in the particle size distribution measured by laser diffraction are defined as D10, D50 and D90, respectively, the D50 of the spherical silica filler powder is 1.2 to 13.2 μm, and is expressed by the following formula 1: [0010] The wavelength conversion member has a SPAN value of 1.0 to 5.

0.

2. The wavelength conversion member according to claim 1 , wherein the spherical silica filler powder has a D90 / D10 of 1.5 to 15.

3. The spherical silica filler powder has a diameter of 1.0 to 6.5 m ２ The wavelength conversion member according to claim 1, having a specific surface area (Brunauer-Emmett-Teller; BET) of 100 nm to 100 nm / g.

4. 2. The wavelength conversion member according to claim 1, wherein the difference in refractive index between the glass matrix and the spherical silica filler powder is 0.01 to 0.

52.

5. The glass matrix has a refractive index of 1.44 to 1.89 and a softening temperature (T ｓ The wavelength conversion member according to claim 1 .

6. The wavelength conversion member according to claim 1, wherein the phosphor powder has an average particle size (D50) of 3 to 30 μm.

7. 2. The wavelength conversion member according to claim 1, wherein the content of the spherical silica filler powder is 0.5 to 50% by weight based on the total weight of the glass matrix, the spherical silica filler powder and the phosphor powder.

8. 2. The wavelength conversion member according to claim 1, wherein a weight ratio of the phosphor powder to the spherical silica filler powder is 1:0.1 to 1:

5.

9. the glass matrix is ​​derived from a glass powder having an average particle size (D50) of 2 to 15 μm, The glass powder has the following composition, based on the total moles of the glass powder: 2 to 10 mol% P ２ O ５ , 30 to 50 mol % ZnO, 10 to 25 mol% SiO ２ , and 15 to 25 mol% B ２ O ３ The wavelength conversion member according to claim 1 ,

10. The glass powder has the following composition: 1 to 10 mol% Al ２ O ３ , 0.1 to 7 mol% SnO ２ , 1 to 5 mol % BaO, 0.1 to 5 mol % SrO, 1 to 5 mol % CaO, 1 to 5 mol% Li ２ O. 1 to 7 mol% Na ２ O and 1 to 5 mol% K ２ O The wavelength conversion member according to claim 9 , further comprising at least one selected from the following:

11. A method for producing the wavelength conversion member according to claim 1, A first step of obtaining a composition for a wavelength conversion member, the composition comprising a glass powder, a phosphor powder, and a spherical silica filler powder; A second step of applying the composition for wavelength conversion members to a substrate to obtain a green sheet for wavelength conversion members; A third step of firing the green sheet for the wavelength conversion member; A method for producing a wavelength conversion member comprising the steps of:

12. A light emitting device comprising: the wavelength conversion member according to any one of claims 1 to 10; and a light source that irradiates the wavelength conversion member with excitation light.

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