WO2019181478A1 - Wavelength conversion member and wavelength conversion element - Google Patents

Wavelength conversion member and wavelength conversion element Download PDF

Info

Publication number
WO2019181478A1
WO2019181478A1 PCT/JP2019/008571 JP2019008571W WO2019181478A1 WO 2019181478 A1 WO2019181478 A1 WO 2019181478A1 JP 2019008571 W JP2019008571 W JP 2019008571W WO 2019181478 A1 WO2019181478 A1 WO 2019181478A1
Authority
WO
WIPO (PCT)
Prior art keywords
wavelength conversion
conversion member
phosphor
single crystal
film
Prior art date
Application number
PCT/JP2019/008571
Other languages
French (fr)
Japanese (ja)
Inventor
飯塚　和幸
理紀也 鈴木
佳弘 山下
祐輔 新井
清太郎 吉田
伊藤　彰
猪股　大介
博之 澤野
島村　清史
ビジョラ エンカルナシオン アントニア ガルシア
Original Assignee
株式会社タムラ製作所
国立研究開発法人物質・材料研究機構
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社タムラ製作所, 国立研究開発法人物質・材料研究機構 filed Critical 株式会社タムラ製作所
Publication of WO2019181478A1 publication Critical patent/WO2019181478A1/en

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/10—Inorganic compounds or compositions
    • C30B29/16—Oxides
    • C30B29/22—Complex oxides
    • C30B29/28—Complex oxides with formula A3Me5O12 wherein A is a rare earth metal and Me is Fe, Ga, Sc, Cr, Co or Al, e.g. garnets
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters

Definitions

  • the present invention relates to a wavelength conversion member and a wavelength conversion element.
  • Patent Document 1 the wavelength conversion caused by the presence of pores containing air having low thermal conductivity by using a single crystal phosphor containing no pores or a polycrystalline phosphor having a low porosity as a wavelength conversion member. It is said that a decrease in the thermal conductivity of the member can be suppressed. Further, since the pores are not included or the porosity is small, the backscattering of the irradiated excitation light is almost eliminated, and the excitation is performed efficiently.
  • the pores are not included or the porosity is small, the light is spread over a wide range because of less scattering in the wavelength conversion member, and the region where the light is emitted becomes large. In this case, since the light extracted from the wavelength conversion member cannot be efficiently condensed by the lens and used, the coupling efficiency with the optical system is low.
  • An object of the present invention is to provide a wavelength conversion member having excellent coupling efficiency with an optical system and a wavelength conversion element including a layer made of the wavelength conversion member.
  • one aspect of the present invention provides the following wavelength conversion members [1] to [3] and wavelength conversion elements [4] to [7].
  • a wavelength conversion member that is made of a sintered body of a phosphor particle group and has an area ratio of 0.6% to 25% with respect to the entire voids at an arbitrary cut surface.
  • the phosphor is represented by the composition formula (Y 1-x-y- z Lu x Gd y Ce z) 3 + a Al 5-a O 12 (0 ⁇ x ⁇ 0.9994,0 ⁇ y ⁇ 0.0669,
  • the wavelength conversion member according to the above [1] which has a composition represented by 0.0002 ⁇ z ⁇ 0.0067, ⁇ 0.016 ⁇ a ⁇ 0.315).
  • a wavelength conversion layer comprising a sintered body of phosphor particle groups and having an area ratio in the range of 0.6% or more and 25% or less with respect to the entire voids at an arbitrary cut surface, and the wavelength conversion layer
  • a wavelength conversion element comprising: a reflection film formed on the opposite side of the light extraction side of the first electrode; and a pad metal formed on the reflection film on the opposite side of the wavelength conversion layer.
  • the phosphor is represented by the composition formula (Y 1-x-y- z Lu x Gd y Ce z) 3 + a Al 5-a O 12 (0 ⁇ x ⁇ 0.9994,0 ⁇ y ⁇ 0.0669,
  • the wavelength conversion element according to the above [4] which has a composition represented by 0.0002 ⁇ z ⁇ 0.0067, ⁇ 0.016 ⁇ a ⁇ 0.315).
  • any one of the above [4] to [6], comprising a planarizing film formed between the wavelength conversion layer and the reflective film and having a flat surface in contact with the reflective film.
  • the wavelength conversion element as described.
  • a wavelength conversion member including a wavelength conversion member excellent in coupling efficiency with an optical system and a layer made of the wavelength conversion member.
  • FIG. 1A is a perspective view of a wavelength conversion member according to the first embodiment.
  • FIG. 1B is a perspective view of the wavelength conversion member according to the first embodiment.
  • FIG. 2A is a diagram schematically showing an optical path of fluorescence emitted from a general wavelength conversion member made of a phosphor and condensed on a lens.
  • FIG. 2B is a diagram schematically illustrating an optical path of fluorescence emitted from a general wavelength conversion member made of a phosphor and collected on a lens.
  • FIG. 3 is an SEM (Scanning / Electron / Microscope) observation image of a cut surface of an example of the wavelength conversion member according to the first embodiment.
  • FIG. 4 is a flowchart showing an example of a manufacturing process of the wavelength conversion member 1 according to the embodiment.
  • FIG. 5 is a cross-sectional view schematically showing pulling of the single crystal phosphor ingot by the CZ method.
  • FIG. 6 is a vertical cross-sectional view of the wavelength conversion element according to the second embodiment.
  • FIG. 7A is a vertical cross-sectional view illustrating the manufacturing process of the wavelength conversion element when a planarization film is formed on the surface of the wavelength conversion layer on the reflection film side.
  • FIG. 7B is a vertical cross-sectional view showing the manufacturing process of the wavelength conversion element when a planarization film is formed on the surface of the wavelength conversion layer on the reflection film side.
  • FIG. 7C is a vertical cross-sectional view illustrating the manufacturing process of the wavelength conversion element when a planarization film is formed on the surface of the wavelength conversion layer on the reflection film side.
  • FIG. 7D is a vertical cross-sectional view illustrating the manufacturing process of the wavelength conversion element when a planarization film is formed on the surface of the wavelength conversion layer on the reflection film side.
  • FIG. 7E is a vertical cross-sectional view illustrating the manufacturing process of the wavelength conversion element when a planarization film is formed on the surface of the wavelength conversion layer on the reflection film side.
  • FIG. 7F is a vertical cross-sectional view illustrating the manufacturing process of the wavelength conversion element in the case where a planarizing film is formed on the surface of the wavelength conversion layer on the reflective film side.
  • FIG. 8 is a vertical sectional view of the wavelength conversion module according to the second embodiment.
  • the wavelength conversion member 1 is made of a sintered body of phosphor particle groups and has a unique shape. Moreover, the area ratio with respect to the whole space
  • the shape of the wavelength conversion member 1 is not particularly limited, but is typically a flat plate shape.
  • the wavelength conversion member 1 has a flat plate shape with a circular planar shape.
  • FIG. 1A is a schematic diagram in the case where mixed light of a part of excitation light and fluorescence obtained by converting the wavelength of excitation light is extracted from the wavelength conversion member 1. For example, when the excitation light is blue light and the fluorescence is yellow light, white light can be extracted from the wavelength conversion member 1.
  • FIG. 1B is a schematic diagram in the case where the wavelength of almost all of the excitation light is converted and only the fluorescence is extracted from the wavelength conversion member 1.
  • the wavelength conversion member 1 is used as a reflection type wavelength conversion member that reflects excitation light and extracts light, but is a transmission type that transmits excitation light and extracts light. It can also be used as a wavelength conversion member.
  • FIGS. 2A and 2B are diagrams schematically showing an optical path of fluorescence emitted from a general wavelength conversion member 30 made of a phosphor and condensed on a lens 31.
  • FIG. “P” in FIGS. 2A and 2B indicates the irradiation position of the excitation light.
  • the fluorescence 32 emitted from the vicinity of the excitation light irradiation position P is condensed by the lens 31 as parallel light.
  • the fluorescence 32 emitted from a position away from the excitation light irradiation position P is not condensed as parallel light by the lens 31 and cannot be used effectively in the optical system.
  • the wavelength conversion member made of a phosphor As described above, when the pores are not included or the porosity is small, light is spread in a wide range due to less scattering in the wavelength conversion member, and emission of fluorescence The area to be increased. In this case, as shown in FIG. 2B, since the amount of light that cannot be used effectively in the optical system increases, the coupling efficiency with the optical system decreases.
  • the wavelength conversion member 1 scatters light in the wavelength conversion member 1 by including pores in such an amount that the area ratio with respect to the entire voids (pores) in an arbitrary cut surface is 0.6% or more. . Thereby, the expansion of the region where the fluorescence is emitted is suppressed, and the coupling efficiency with the optical system is increased. Further, the wavelength conversion member 1 includes more pores in such an amount that the area ratio with respect to the entire voids (pores) in an arbitrary cut surface is 1% or more, so that the light is more effectively scattered, and the optical system The coupling efficiency can be further increased.
  • the porosity is too high, the mechanical strength and thermal conductivity of the wavelength conversion member 1 may be reduced to an impractical level. Therefore, voids (pores) in an arbitrary cut surface of the wavelength conversion member 1 may be reduced.
  • the area ratio with respect to the whole is 25% or less, preferably 15% or less.
  • FIG. 3 is an SEM (Scanning Electron Microscope) observation image of a cut surface of an example of the wavelength conversion member 1.
  • the wavelength conversion member 1 shown in FIG. 3 is a sintered body of a single crystal phosphor having a composition represented by the composition formula (Y 0.998 Ce 0.002 ) 3 Al 5 O 12 .
  • a portion indicated by an arrow is a void (a pore), and a portion of the same color that occupies most is a phosphor.
  • gap in the arbitrary cut surfaces of the wavelength conversion member 1 can be measured using SEM observation.
  • the wavelength conversion member 1 since the wavelength conversion member 1 is composed of a group of phosphor particles, it has a grain boundary inside. Since the grain boundary scatters light in the same manner as the pores, it is important for improving the coupling efficiency of the wavelength conversion member 1 with the optical system.
  • the wavelength conversion member 1 has an excellent internal quantum efficiency.
  • the particulate phosphor constituting the wavelength conversion member 1 is composed of a composition formula (Y 1-xy-Z Lu x Gd y Ce z ) 3 + a Al 5-a O 12 (0 ⁇ x ⁇ 0.9994, 0 ⁇ y ⁇ 0.0669, 0.0002 ⁇ z ⁇ 0.0067, ⁇ 0.016 ⁇ a ⁇ 0.315), the temperature is 25 ° C., the excitation light The internal quantum efficiency when the peak wavelength is 450 nm is 0.95 or more, the internal quantum efficiency is 0.90 or more when the temperature is 300 ° C. and the peak wavelength of the excitation light is 450 nm.
  • the temperature is 25 ° C.
  • the peak wavelength of the excitation light is 450 nm
  • the internal quantum efficiency is 0.99 or more
  • the temperature is 300 ° C. and the peak wavelength of the excitation light is 450 nm
  • the internal quantum efficiency is 0.90 or more.
  • the particulate phosphor constituting the wavelength conversion member 1 is a single crystal having a composition represented by the composition formula (Lu 0.998 Ce 0.002 ) 3 Al 5 O 12
  • the temperature is 25 ° C.
  • the peak wavelength of the excitation light is 450 nm
  • the internal quantum efficiency is 0.99 or more
  • the temperature is 300 ° C. and the peak wavelength of the excitation light is 450 nm
  • the internal quantum efficiency is 0.93 or more.
  • the wavelength conversion member 1 can maintain high internal quantum efficiency even under a high temperature condition of 300 ° C., for example, a unit such as a laser projector or a laser headlight whose excitation light is laser light. An excellent function as a wavelength conversion member used in a light emitting device having extremely high luminance per area can be exhibited.
  • the thickness of the wavelength conversion member 1 is preferably 0.3 mm or less.
  • the wavelength conversion member 1 made of a YAG single crystal phosphor is irradiated with blue laser light of 20 W or more with a spot diameter of 3.0 mm or less.
  • the thickness is preferably 0.3 mm or less in consideration of the thermal conductivity of the wavelength conversion member 1.
  • the wavelength conversion member 1 when irradiating the wavelength conversion member 1 made of a YAG single crystal phosphor with a blue laser beam of 2 W or more with a spot diameter of 0.300 mm or less for use in a vehicle headlight or flashlight, the wavelength conversion member In consideration of the thermal conductivity of 1, the thickness is preferably 0.3 mm or less. In order to suppress cracking during processing, the thickness of the wavelength conversion member 1 is preferably 0.05 mm or more.
  • the phosphor constituting the wavelength conversion member 1 may be a single crystal phosphor.
  • the wavelength conversion member 1 is preferably made of a sintered body of particle groups of single crystal phosphors.
  • a YAG-based single crystal phosphor has a lower decrease in fluorescence intensity with an increase in temperature than a YAG-based polycrystalline phosphor.
  • the decrease in fluorescence intensity is small because the decrease in internal quantum efficiency is small.
  • the phosphor constituting the wavelength conversion member 1 is not particularly limited, but is preferably a YAG phosphor having excellent temperature characteristics.
  • the YAG phosphor is a phosphor having a Y 3 Al 5 O 12 (YAG) crystal as a mother crystal.
  • the phosphors of the wavelength conversion member 1 the composition formula (Y 1-x-y- z Lu x Gd y Ce z) 3 + a Al 5-a O 12 (0 ⁇ x ⁇ 0.9994,0 ⁇ y ⁇ 0.0669, 0.0002 ⁇ z ⁇ 0.0067, ⁇ 0.016 ⁇ a ⁇ 0.315), a YAG-based phosphor having a composition represented by the formula (Y 0.998 Ce 0.002 ) YAG phosphor having a composition represented by 3 Al 5 O 12, may be used LuAG phosphor having a composition represented by composition formula (Lu 0.998 Ce 0.002) 3 Al 5 O 12.
  • Lu and Gd are components that do not serve as the emission center for substituting Y.
  • Ce is a component (activator) that can serve as a luminescent center for substituting Y.
  • the above phosphor composition some atoms may occupy different positions on the crystal structure.
  • the value of O in the composition ratio in the above composition formula is described as 12, the above composition is slightly deviated from 12 in the composition ratio due to the presence of inevitably mixed or missing oxygen. Also includes composition.
  • the value of a in the composition formula is a value that inevitably changes in the production of the phosphor, but the change within the numerical range of about ⁇ 0.016 ⁇ a ⁇ 0.315 indicates the physical properties of the phosphor. Has little effect on
  • the range of the numerical value of z in the above composition formula representing the concentration of Ce is 0.0002 ⁇ z ⁇ 0.0067 because when the numerical value of z is smaller than 0.0002, the Ce concentration is too low.
  • the problem is that the absorption of excitation light becomes small and the external quantum efficiency becomes too small, and when it is larger than 0.0067, cracks and voids occur when growing an ingot of a single crystal phosphor, and the crystal quality is low. This is because there is a high possibility of a decrease.
  • the numerical value of z is 0.0010 or more, wavelength conversion can be sufficiently performed even if the wavelength conversion member 1 is thin, so that cost reduction and heat dissipation can be improved.
  • the phosphor constituting the wavelength conversion member 1 is a YAG phosphor, it does not contain a group 2 element such as Ba and Sr and a group 17 element such as F and Br, and preferably has high purity. As a result, a phosphor with high brightness and long life can be realized.
  • the phosphor constituting the wavelength conversion member 1 is a single crystal phosphor
  • CZ method Czochralski Method
  • EFG method Edge Film Fed Growth Method
  • Bridgman method Bridgman method
  • FZ method Floating Zone Method
  • the single crystal phosphor particles can be obtained by pulverizing the single crystal phosphor ingots obtained by the liquid phase growth method.
  • the particle diameter (D50) is preferably in the range of 3 ⁇ m to 30 ⁇ m, preferably 3 ⁇ m to 15 ⁇ m. It is more preferable to be within the following range.
  • D50 refers to the particle size at 50 vol% in the cumulative distribution.
  • the particle diameter (D50) When the particle diameter (D50) is 30 ⁇ m or less, the sintering easily proceeds and the pores become small, so that a decrease in the thermal conductivity of the wavelength conversion member 1 due to the pores can be suppressed. If the thermal conductivity is high, high intensity excitation light can be irradiated. Furthermore, when the particle size (D50) is 15 ⁇ m or less, the density of the wavelength conversion member 1 is further increased, and the thermal conductivity is improved. On the other hand, when the particle size (D50) is smaller than 3 ⁇ m, the sintering is easy to proceed, but since the number of pores is too small, light scattering inside the wavelength conversion member 1 is reduced, and the light distribution characteristic is Lambertian light distribution. Get away from. Therefore, the coupling efficiency between the wavelength conversion member 1 and the optical system is reduced. Moreover, when a particle size is too small, the problem that wavelength conversion efficiency and heat conductivity fall will also arise.
  • YAG polycrystalline phosphors synthesize oxide powder raw materials such as Y 2 O 3 , Al 2 O 3 , and CeO 2 by solid phase reaction, they produce phosphors with a particle size larger than about 15 to 20 ⁇ m. Difficult to do.
  • the single crystal YAG phosphor is produced by pulverizing an ingot of a single crystal phosphor that has been melt-grown, a single crystal YAG phosphor having a particle diameter of 100 ⁇ m or more can be obtained.
  • the wavelength conversion member 1 does not include a phosphor sealing material or a binder even when the wavelength conversion member 1 is composed of a single crystal phosphor particle group.
  • the sealing material and the binder have a lower thermal conductivity than the single crystal phosphor, and the heat dissipation of the wavelength conversion member is lowered by using these.
  • the single crystal phosphor particles obtained by pulverizing the single crystal phosphor ingot are solidified by applying pressure to the single crystal phosphor particles. By doing so, a sintered body of the single crystal phosphor particle group is obtained.
  • a SPS (Spark Plasma Sintering) method or a CIP (Cold Isostatic Pressing) method can be used for solidifying and sintering the particle group of the single crystal phosphor.
  • the mixed raw material is solid-phase-reacted using SPS method or CIP method, and is sintered, and thereby has a predetermined shape.
  • a sintered body of phosphor particles is obtained.
  • powders of Y 2 O 3 , Lu 2 O 3 , Gd 2 O 3 , Al 2 O 3 , and CeO 2 as raw materials are used. Mix in an amount that matches the garnet composition and allow a solid phase reaction.
  • the void ratio is controlled by the particle size of the phosphor particles, the pressure in the sintering process, the firing temperature, the firing time, and the like.
  • the larger the particle size of the phosphor particles the larger the voids, so the void ratio increases.
  • the particle size of the phosphor particles can be controlled by, for example, the processing time of the fine pulverization processing of the particles using a planetary ball mill.
  • the pressure in the sintering process is small, the voids remain without being crushed, and the void ratio increases.
  • the firing proceeds further, so the voids are reduced and the void ratio is reduced.
  • FIG. 4 is a flowchart showing an example of a manufacturing process of the wavelength conversion member 1 according to the embodiment.
  • FIG. 4 shows, as an example, the flow of a manufacturing process of the wavelength conversion member 1 made of a sintered body of YAG-based single crystal phosphor particles.
  • a single crystal phosphor is grown to obtain an ingot (step S1).
  • high-purity 99.99% or more
  • Y 2 O 3 , Lu 2 O 3 , Gd 2 O 3 , CeO 2 , and Al 2 O 3 powders are prepared, dry mixed, and the mixed powders are prepared. obtain.
  • the raw material powders of Y, Lu, Gd, Ce, and Al are not limited to the above. Further, when producing a single crystal phosphor containing no Lu or Gd, those raw material powders are not used.
  • FIG. 5 is a cross-sectional view schematically showing pulling of the single crystal phosphor ingot by the CZ method.
  • the crystal growing apparatus 40 mainly includes an iridium crucible 41, a ceramic cylindrical container 42 that houses the crucible 41, and a high-frequency coil 43 that is wound around the cylindrical container 42.
  • the obtained mixed powder is put in the crucible 41, and high-frequency energy of 30 kW is supplied to the crucible 41 in the nitrogen atmosphere by the high-frequency coil 43 to generate an induced current, and the crucible 41 is heated. As a result, the mixed powder is melted to obtain a melt 50.
  • the tip of the seed crystal 51 which is a YAG-based single crystal phosphor
  • the tip of the seed crystal 51 is brought into contact with the melt 50, it is pulled up at a pulling speed of 1 mm / h or less while rotating at a rotation speed of 10 rpm, and a pulling temperature of 1960 ° C. or higher.
  • the single crystal phosphor ingot 52 is grown in the ⁇ 111> direction.
  • the single crystal phosphor ingot 52 is grown by flowing nitrogen into the cylindrical container 42 at a flow rate of 2 L / min in a nitrogen atmosphere under atmospheric pressure.
  • a single crystal phosphor ingot 52 having a diameter of about 2.5 cm and a length of about 10 cm is obtained.
  • the single crystal phosphor ingot is pulverized into particles (step S2).
  • an ingot of a single crystal phosphor is coarsely pulverized by rapid heating and rapid cooling to obtain a single crystal phosphor particle group having a particle size of about 1 to 3 mm.
  • the rapid heating can be performed using a hydrogen / oxygen mixed gas burner.
  • the rapid cooling can be performed by water cooling.
  • the particles are pulverized using a planetary ball mill and then dried.
  • the particle size (D50) of the particle group can be in the range of 3 ⁇ m or more and 30 ⁇ m or less, more preferably in the range of 3 ⁇ m or more and 15 ⁇ m or less.
  • the single crystal phosphor particles are solidified by applying pressure (step S3).
  • the solidification method is not particularly limited, and for example, an SPS method, a CIP method, or the like can be used. Further, solidification may be performed by sheet molding or slip casting. When these methods are used, an organic binder is required to hold the particle group on the wafer, and this organic binder can be removed in the process.
  • the magnitude of pressure applied to the particle group during solidification is large enough to hold the particle group in a solid state, and depends on the solidification method.
  • the pressure is preferably 100 MPa or more.
  • step S4 the solidified single crystal phosphor particles are sintered.
  • the mechanical strength of the solidified single crystal phosphor particles is improved, and the internal quantum efficiency is improved.
  • the temperature and holding time of the heat treatment for sintering depends on the sintering method.
  • sintering is performed under an argon atmosphere.
  • the amount of increase in internal quantum efficiency is larger than when the sintering is performed in an atmosphere of air, oxygen, nitrogen, or a mixed gas of Ar 97.5% and hydrogen 2.5%. It has been confirmed by the present inventors.
  • the temperature and holding time of the heat treatment for sintering depend on the type of single crystal phosphor and the sintering method.
  • the temperature of the heat treatment is preferably in the range of 1650 ° C. or higher and 1850 ° C. or lower.
  • the holding time after reaching the target temperature is preferably in the range of 1 hour or more and 10 hours or less.
  • the temperature of the heat treatment When the temperature of the heat treatment is lower than 1650 ° C., it takes a long time to sinter, and uneven sintering is likely to occur. When the temperature exceeds 1850 ° C., the phosphor may melt. If the holding time is shorter than 1 hour, sintering may be insufficient, and if it is longer than 10 hours, uniformity of grain size is lost as a result of excessive sintering and grain growth. .
  • step S4 is also continuously performed in the SPS apparatus.
  • the single crystal phosphor is a YAG single crystal phosphor
  • heat treatment at 1530 ° C. to 1600 ° C. is performed in a state where a pressure of 30 MPa or more is applied to the particle group of the single crystal phosphor.
  • the density of the single crystal phosphor particle group increases, and the piston that applies pressure to the single crystal phosphor particle group displaces.
  • This holding time is preferably in the range of 30 seconds or more and 3 minutes or less. When the time is shorter than 30 seconds, the sintering may be insufficient. When the time is longer than 3 minutes, the sintering proceeds so much that the uniformity of the particle size is lost.
  • the sintered body of the single crystal phosphor particle group is sliced to obtain a wafer-like sintered body (step S5).
  • Slicing can be performed using a multi-wire saw or the like.
  • the thickness of the wafer-like sintered body is preferably 0.15 mm or more.
  • the thickness of the wafer-like sintered body is preferably 1.0 mm or less.
  • step S6 annealing treatment is performed on the sintered body of the particle group of the wafer-like single crystal phosphor.
  • the annealing temperature is too low or the time is too short, the quantum efficiency of the sintered body of the single crystal phosphor particle group is not sufficiently improved. Moreover, if the temperature of annealing treatment is too high, the load of an apparatus will become large, and if it raises extremely, a sintered compact will melt
  • the annealing treatment time is preferably 15 hours or less.
  • the annealing process is performed in an argon atmosphere.
  • the amount of increase in internal quantum efficiency is larger than that in the atmosphere, oxygen atmosphere, nitrogen atmosphere, or a mixed gas atmosphere of Ar 97.5% and hydrogen 2.5%. It has been confirmed by the present inventors.
  • the sintered body of the particle group of the wafer-like single crystal phosphor is subjected to polishing treatment (step S7).
  • the polishing process is performed, for example, by a combination of grinding, diamond slurry polishing, CMP (Chemical Mechanical Polishing), and the like.
  • the polishing treatment is performed until the desired wavelength conversion member 1 thickness (preferably 0.05 mm or more and 0.3 mm or less) is obtained.
  • a wafer-shaped wavelength conversion member 1 made of a sintered body of YAG-based single crystal phosphor particles is obtained.
  • FIG. 6 is a vertical sectional view of the wavelength conversion element 10 according to the second embodiment.
  • the wavelength conversion element 10 is formed on the surface of the wavelength conversion layer 11 including the wavelength conversion member 1 according to the first embodiment and the opposite side of the light extraction side of the wavelength conversion layer 11 (hereinafter referred to as the back side).
  • an antireflection film 15 formed on the substrate.
  • the wavelength conversion layer 11 includes the wavelength conversion member 1. That is, the wavelength conversion layer 11 is made of a sintered body of phosphor particle groups, and the area ratio with respect to the entire voids in an arbitrary cut surface of the wavelength conversion layer 11 is in the range of 0.6% or more and 25% or less. Preferably, it exists in the range of 1% or more and 15% or less.
  • the thickness of the wavelength conversion layer 11 is preferably in the range of 0.050 or more and 0.3 mm or less, similarly to the wavelength conversion member 1.
  • the reflective film 12 is, for example, a metal film made of a highly reflective metal such as silver, a silver alloy, or aluminum, a dielectric multilayer film, or a combination thereof.
  • the material of the high refractive index film is TiO 2.
  • a material for the low refractive index film such as 2 , ZrO 2 , or ZnO, SiO 2 , CaF 2 , MgF 2, or the like can be used.
  • the average reflectance with respect to the wavelength of light from the wavelength conversion layer 11 side is preferably 90 or more.
  • the protective film 13 prevents the reflective film 12 from being mixed with solder and pad metal 14, thereby reducing the reflectance of the reflective film 12.
  • the reflective film 12 is made of metal (for example, silver, aluminum, or an alloy thereof)
  • the protective film 13 is necessary to protect the reflective film 12.
  • silver when silver is used for the reflective film 12, it is necessary to cover the side of the reflective film 12 with the protective film 13 in order to prevent the sulfidation phenomenon.
  • the material of the protective film 13 is preferably a thermally stable oxide, nitride, refractory metal or the like, and specifically, SiO 2 , SiN, TiN, AlN, TiW, Pt or the like is used. it can.
  • the reflective film 12 is made of a material that is not easily eroded by a solder such as a dielectric or the pad metal 14, the wavelength conversion element 10 may not include the protective film 13.
  • the pad metal 14 has a configuration with high wettability to solder.
  • it has a laminated film structure of Ti / Ni / Au, Ti / Pt / Au, etc. from the reflective film 12 side (protective film 13 side).
  • the antireflection film 15 can suppress reflection of excitation light on the surface when the excitation light enters the wavelength conversion element 10.
  • the antireflection film 15 is made of a single-layer film or a multilayer film of a dielectric film that is transparent to visible light. Instead of providing the antireflection film 15, unevenness may be provided on the light extraction side surface of the wavelength conversion layer 11 to suppress reflection of excitation light. In addition, an antireflection film 15 may be further provided after unevenness is provided on the light extraction side surface of the wavelength conversion layer 11.
  • the reflective film 12 and the protective film 13 are formed on a flat surface.
  • the reflective film 12 is made of a dielectric multilayer film, it is important that the refractive index and thickness of each layer be as designed in order to achieve a high reflectance, and the reflection is performed on a flat surface. It is preferable to form the film 12. For these reasons, since the porosity is relatively high, a flat film is provided on the reflective film 12 side surface of the wavelength conversion layer 11 having irregularities on the surface, and the reflective film 12 and the protective film 13 are formed thereon. It is preferable.
  • 7A to 7F are vertical sectional views showing the manufacturing process of the wavelength conversion element 10 when the planarization film 16 is formed on the surface of the wavelength conversion layer 11 on the reflective film 12 side. 7A to 7F, the pores are shown extremely large in order to emphasize the irregularities on the surface of the wavelength conversion layer 11.
  • a planarizing film 16 is formed on the back surface of the wavelength conversion layer 11 by a CVD method, a sputtering method, a vapor deposition method, an SOG (Spin on Glass) method, or the like.
  • the flattening film 16 is a film transparent to visible light, such as a SiO 2 film, a glass layer formed by screen printing, a coating method, and a baking process.
  • the planarization film 16 has not yet been planarized, and has irregularities corresponding to the irregularities on the surface of the wavelength conversion layer 11.
  • the flattening film 16 is flattened by performing a flattening process such as grinding, diamond slurry polishing, and CMP. As a result, the surface of the planarizing film 16 that contacts the reflective film 12 becomes a flat surface.
  • the planarization film 16 is preferably formed to be relatively thick and then subjected to a planarization process in order to fill the holes on the surface of the wavelength conversion layer 11 more reliably.
  • a film that can be formed relatively thick and is transparent to visible light generally has a low thermal conductivity. Therefore, in order to efficiently release the heat generated in the wavelength conversion layer 11 to a heat sink or the like connected to the pad metal 14, it is preferable to make the planarizing film 16 as thin as possible within a range in which the planarity can be maintained.
  • the planarizing film 16 is a transparent and non-scattering film, if the planarizing film 16 is too thick, light may spread through the planarizing film 16 and the coupling efficiency with the lens may be reduced. is there.
  • the thickness of the planarizing film 16 is preferably 30 ⁇ m or less, and more preferably 10 ⁇ m or less.
  • the reflective film 12 is formed on the flattened film 16 by the sputtering method, the vapor deposition method, or the like.
  • a protective film 13 is formed so as to cover the surface and side surfaces of the reflective film 12.
  • a pad metal 14 is formed on the protective film 13 by sputtering, vapor deposition, or the like. Further, an antireflection film 15 may be formed on the light extraction side surface of the wavelength conversion layer 11 as necessary.
  • the individual wavelength conversion elements 10 are separated into pieces by blade dicing or the like.
  • FIG. 8 is a vertical sectional view of the wavelength conversion module 20 according to the second embodiment.
  • the wavelength conversion module 20 is a module in which the wavelength conversion element 10 is fixed to the heat sink 21 with solder, and the pad metal 14 of the wavelength conversion element 10 and the heat sink 21 are connected via the solder 22. In addition, after solder mounting, since the solder 22 and the pad metal 14 are mixed, the pad metal 14 may not be visible.
  • the solder 22 made of a metal material can efficiently dissipate heat generated in the wavelength conversion layer 11. If the melting point of the solder 22 is too low, the wavelength conversion element 10 may be peeled off from the heat sink 21 when the temperature of the wavelength conversion layer 11 rises. Further, if the melting point of the solder 22 is too high, the reflective film 12 may be deteriorated by heat when the wavelength conversion element 10 is mounted.
  • the material of the solder 22 is preferably SnAgCu (SAC), AuSn, AuGe, or AuSi.
  • the heat sink 21 is preferably made of a material having high thermal conductivity such as Cu, CuW, CuMo, SiC, AlN, diamond, etc., in order to efficiently lower the temperature of the wavelength conversion layer 11. Furthermore, in order to prevent the wavelength conversion layer 11 from cracking, the heat sink 21 preferably has a linear expansion coefficient comparable to that of the wavelength conversion layer 11. For example, when the wavelength conversion layer 11 is made of a sintered body of a YAG phosphor particle group, CuW or CuMo having a linear expansion coefficient comparable to that of the wavelength conversion layer 11 among the above-described high thermal conductivity materials is used. It is preferable as a material for the heat sink 21.
  • the wavelength conversion member 1 having excellent coupling efficiency with the optical system can be provided.
  • the wavelength conversion element 10 excellent in the coupling efficiency with an optical system including the wavelength conversion layer 11 which consists of the wavelength conversion member 1, and the wavelength conversion module 20 are provided. Can do.
  • Example 1 shows an example of a method for producing a wavelength conversion member 1 made of a sintered body of a YAG-based single crystal phosphor particle group using an SPS method.
  • step S1 an ingot of a single crystal phosphor having a composition represented by the composition formula (Y 0.998 Ce 0.002 ) 3 Al 5 O 12 was grown by the CZ method (step S1).
  • the single crystal phosphor ingot was pulverized into particles (step S2).
  • the single crystal phosphor ingot was subjected to rapid heating using a hydrogen / oxygen mixed gas burner and rapid cooling by water cooling and coarsely pulverized to obtain a single crystal phosphor particle group having a particle size of about 1 to 3 mm. .
  • the particle group was dried at 80 ° C. for 1 day.
  • a phosphor single crystal particle group having a particle size (D50) of about 5 ⁇ m was obtained.
  • a ball made of aluminum oxide was used as the ball of the planetary ball mill. Further, in the fine pulverization using a planetary ball mill, the volume ratio of the coarsely pulverized single crystal phosphor particles, the ball and ethanol was set to 1: 1: 1.
  • step S3 and S4 solidification and sintering of the single crystal phosphor particles were carried out by the SPS method to obtain a sintered body.
  • the single crystal phosphor particles were pre-pressed and then housed in a carbon jig having an inner diameter of 20 mm in the SPS apparatus.
  • the SPS apparatus was evacuated and then replaced with an argon atmosphere (1 atm).
  • a pressure of 80 MPa was applied to the single crystal phosphor particles in the carbon jig with a piston through a carbon punch.
  • a current was passed through the carbon punch and the carbon jig while applying a pressure of 80 MPa to heat the particle group of the single crystal phosphor.
  • the temperature inside the carbon jig reached the target temperature of 1570 ° C. in about 10 minutes after the start of heating.
  • a hole having a diameter of 1 mm and a depth of 2 mm is formed on the side surface of the carbon jig, and the temperature inside the carbon jig can be measured using a pyrometer.
  • step S5 the sintered body of the single crystal phosphor particle group was sliced into a wafer having a thickness of 0.5 mm using a multi-wire saw.
  • Step S6 the sintered body of the particle group of the wafer-like single crystal phosphor was annealed.
  • a sintered body of a group of wafer-like single crystal phosphor particles was accommodated in an annealing furnace, and the inside of the annealing furnace was evacuated and then replaced with an argon atmosphere.
  • the temperature in the annealing furnace was raised to 1500 ° C. in about 4 hours, held at 1500 ° C. for 10 hours, and then lowered to room temperature in about 4 hours.
  • the wafer-like single crystal phosphor particle group sintered body was subjected to a polishing process by grinding and diamond slurry polishing (step S7).
  • the thickness of the sintered body of the particle group of the wafer-like single crystal phosphor was reduced from 0.5 mm to 0.15 mm.
  • a wafer-shaped wavelength conversion member comprising a sintered body of single crystal phosphor particles having a composition represented by the composition formula (Y 0.998 Ce 0.002 ) 3 Al 5 O 12. 1 was obtained.
  • Example 2 shows an example of a method of manufacturing the wavelength conversion member 1 made of a sintered body of a YAG-based single crystal phosphor particle group using a CIP method.
  • the ingot growing process (step S1), the crushing process (step S2), the slicing process (step S5), the annealing process (step S6), and the polishing process (step S7) are the same as in the first embodiment. Therefore, the description is omitted.
  • the single crystal phosphor particles were solidified by the CIP method (step S3).
  • the single crystal phosphor particles were pre-pressed and then housed in a rubber jig having an inner diameter of ⁇ 20 mm in a CIP apparatus.
  • the inside of the CIP device was pressurized and solidified by applying a pressure of 300 MPa to the particle group of the single crystal phosphor at room temperature.
  • the solidified single crystal phosphor particles were sintered (step S5).
  • the solidified single crystal phosphor particles are accommodated in a firing furnace, and the temperature in the firing furnace is raised to 1800 ° C. in about 8 hours under normal pressure while flowing argon gas into the firing furnace. After maintaining at 1800 ° C. for 10 hours, the temperature was lowered to room temperature in about 8 hours.
  • a sintered body of a single crystal phosphor particle group having a columnar shape (a flat plate shape having a circular planar shape) having a diameter of 17.5 mm and a height of 10 mm was obtained.
  • the composition represented by the composition formula (Y 0.998 Ce 0.002 ) 3 Al 5 O 12 is passed through a slicing process (step S5), an annealing process (step S6), and a polishing process (step S7).
  • a wafer-shaped wavelength conversion member 1 made of a sintered body of a single crystal phosphor particle group was obtained.
  • a wavelength conversion member having excellent coupling efficiency with an optical system, and a wavelength conversion element including a layer made of the wavelength conversion member.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Organic Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Engineering & Computer Science (AREA)
  • Inorganic Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Luminescent Compositions (AREA)
  • Optical Filters (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)

Abstract

Provided are: a wavelength conversion member that has excellent coupling efficiency with respect to an optical system; and a wavelength conversion element that includes a layer comprising said wavelength conversion member. One embodiment according to the present invention provides a wavelength conversion member 1 which comprises a sintered body of groups of fluorescence substance particles, wherein, in a given cross section, the area ratio of voids to the entire cross-sectional area falls within a range of 0.6-25%.

Description

波長変換部材及び波長変換素子Wavelength conversion member and wavelength conversion element
　本発明は、波長変換部材及び波長変換素子に関する。 The present invention relates to a wavelength conversion member and a wavelength conversion element.
　従来、励起光を吸収して波長の異なる光を発する波長変換部材として、単結晶蛍光体又は気孔率が０．５％以下の多結晶蛍光体よりなるものが知られている（例えば、特許文献１参照）。 Conventionally, as a wavelength conversion member that absorbs excitation light and emits light having a different wavelength, one made of a single crystal phosphor or a polycrystalline phosphor having a porosity of 0.5% or less is known (for example, Patent Documents). 1).
　特許文献１によれば、気孔を含まない単結晶蛍光体又は気孔率が低い多結晶蛍光体を波長変換部材として用いることにより、熱伝導率の低い空気を含む気孔の存在に起因する、波長変換部材の熱伝導率の低下を抑えることができるとされている。また、気孔を含まない又は気孔率が小さいために、照射される励起光の後方散乱が殆どなくなり、効率よく励起が行われるとされている。 According to Patent Document 1, the wavelength conversion caused by the presence of pores containing air having low thermal conductivity by using a single crystal phosphor containing no pores or a polycrystalline phosphor having a low porosity as a wavelength conversion member. It is said that a decrease in the thermal conductivity of the member can be suppressed. Further, since the pores are not included or the porosity is small, the backscattering of the irradiated excitation light is almost eliminated, and the excitation is performed efficiently.
特許第６１６４２２１号公報Japanese Patent No. 6164221
　しかしながら、気孔を含まない場合や気孔率が小さい場合、波長変換部材内において散乱が少ないために光が広範囲に拡がり、光の出射される領域が大きくなる。この場合、波長変換部材から取り出された光をレンズにより効率的に集光して用いることができないため、光学系との結合効率が低い。 However, when the pores are not included or the porosity is small, the light is spread over a wide range because of less scattering in the wavelength conversion member, and the region where the light is emitted becomes large. In this case, since the light extracted from the wavelength conversion member cannot be efficiently condensed by the lens and used, the coupling efficiency with the optical system is low.
　本発明の目的は、光学系との結合効率に優れた波長変換部材、及びその波長変換部材からなる層を含む波長変換素子を提供することにある。 An object of the present invention is to provide a wavelength conversion member having excellent coupling efficiency with an optical system and a wavelength conversion element including a layer made of the wavelength conversion member.
　本発明の一態様は、上記目的を達成するために、下記［１］～［３］の波長変換部材、［４］～［７］の波長変換素子を提供する。 To achieve the above object, one aspect of the present invention provides the following wavelength conversion members [1] to [3] and wavelength conversion elements [4] to [7].
［１］蛍光体の粒子群の焼結体からなり、任意の切断面における空隙の全体に対する面積比率が０．６％以上、２５％以下の範囲内にある、波長変換部材。 [1] A wavelength conversion member that is made of a sintered body of a phosphor particle group and has an area ratio of 0.6% to 25% with respect to the entire voids at an arbitrary cut surface.
［２］前記蛍光体が、組成式（Ｙ１－ｘ－ｙ－ｚＬｕｘＧｄｙＣｅｚ）３＋ａＡｌ５－ａＯ１２（０≦ｘ≦０．９９９４、０≦ｙ≦０．０６６９、０．０００２≦ｚ≦０．００６７、－０．０１６≦ａ≦０．３１５）で表される組成を有する、上記［１］に記載の波長変換部材。 [2] The phosphor is represented by the composition formula (Y 1-x-y- z Lu x Gd y Ce z) 3 + a Al 5-a O 12 (0 ≦ x ≦ 0.9994,0 ≦ y ≦ 0.0669, The wavelength conversion member according to the above [1], which has a composition represented by 0.0002 ≦ z ≦ 0.0067, −0.016 ≦ a ≦ 0.315).
［３］前記蛍光体の粒子群が、単結晶蛍光体の粒子群である、上記［１］又は［２］に記載の波長変換部材。 [3] The wavelength conversion member according to [1] or [2] above, wherein the phosphor particle group is a single crystal phosphor particle group.
［４］蛍光体の粒子群の焼結体からなり、任意の切断面における空隙の全体に対する面積比率が０．６％以上、２５％以下の範囲内にある波長変換層と、前記波長変換層の光取り出し側の反対側に形成された反射膜と、前記反射膜の前記波長変換層の反対側に形成されたパッドメタルと、を備えた、波長変換素子。 [4] A wavelength conversion layer comprising a sintered body of phosphor particle groups and having an area ratio in the range of 0.6% or more and 25% or less with respect to the entire voids at an arbitrary cut surface, and the wavelength conversion layer A wavelength conversion element comprising: a reflection film formed on the opposite side of the light extraction side of the first electrode; and a pad metal formed on the reflection film on the opposite side of the wavelength conversion layer.
［５］前記蛍光体が、組成式（Ｙ１－ｘ－ｙ－ｚＬｕｘＧｄｙＣｅｚ）３＋ａＡｌ５－ａＯ１２（０≦ｘ≦０．９９９４、０≦ｙ≦０．０６６９、０．０００２≦ｚ≦０．００６７、－０．０１６≦ａ≦０．３１５）で表される組成を有する、上記［４］に記載の波長変換素子。 [5] The phosphor is represented by the composition formula (Y 1-x-y- z Lu x Gd y Ce z) 3 + a Al 5-a O 12 (0 ≦ x ≦ 0.9994,0 ≦ y ≦ 0.0669, The wavelength conversion element according to the above [4], which has a composition represented by 0.0002 ≦ z ≦ 0.0067, −0.016 ≦ a ≦ 0.315).
［６］前記蛍光体の粒子群が、単結晶蛍光体の粒子群である、上記［４］又は［５］に記載の波長変換素子。 [6] The wavelength conversion element according to [4] or [5] above, wherein the phosphor particle group is a single crystal phosphor particle group.
［７］前記波長変換層と前記反射膜との間に形成され、前記反射膜と接する面が平坦面である平坦化膜を備えた、上記［４］～［６］のいずれか１項に記載の波長変換素子。 [7] In any one of the above [4] to [6], comprising a planarizing film formed between the wavelength conversion layer and the reflective film and having a flat surface in contact with the reflective film. The wavelength conversion element as described.
　本発明によれば、光学系との結合効率に優れた波長変換部材、及びその波長変換部材からなる層を含む波長変換素子を提供することができる。 According to the present invention, it is possible to provide a wavelength conversion member including a wavelength conversion member excellent in coupling efficiency with an optical system and a layer made of the wavelength conversion member.
図１Ａは、第１の実施の形態に係る波長変換部材の斜視図である。FIG. 1A is a perspective view of a wavelength conversion member according to the first embodiment. 図１Ｂは、第１の実施の形態に係る波長変換部材の斜視図である。FIG. 1B is a perspective view of the wavelength conversion member according to the first embodiment. 図２Ａは、蛍光体からなる一般的な波長変換部材から発せられてレンズに集光される蛍光の光路を模式的に示す図である。FIG. 2A is a diagram schematically showing an optical path of fluorescence emitted from a general wavelength conversion member made of a phosphor and condensed on a lens. 図２Ｂは、蛍光体からなる一般的な波長変換部材から発せられてレンズに集光される蛍光の光路を模式的に示す図である。FIG. 2B is a diagram schematically illustrating an optical path of fluorescence emitted from a general wavelength conversion member made of a phosphor and collected on a lens. 図３は、第１の実施の形態に係る波長変換部材の一例の切断面のＳＥＭ（Scanning Electron Microscope）観察像である。FIG. 3 is an SEM (Scanning / Electron / Microscope) observation image of a cut surface of an example of the wavelength conversion member according to the first embodiment. 図４は、実施の形態に係る波長変換部材１の製造工程の一例を示すフローチャートである。FIG. 4 is a flowchart showing an example of a manufacturing process of the wavelength conversion member 1 according to the embodiment. 図５は、ＣＺ法による単結晶蛍光体インゴットの引き上げを模式的に示す断面図である。FIG. 5 is a cross-sectional view schematically showing pulling of the single crystal phosphor ingot by the CZ method. 図６は、第２の実施の形態に係る波長変換素子の垂直断面図である。FIG. 6 is a vertical cross-sectional view of the wavelength conversion element according to the second embodiment. 図７Ａは、波長変換層の反射膜側の面上に平坦化膜を形成する場合の波長変換素子の製造工程を示す垂直断面図である。FIG. 7A is a vertical cross-sectional view illustrating the manufacturing process of the wavelength conversion element when a planarization film is formed on the surface of the wavelength conversion layer on the reflection film side. 図７Ｂは、波長変換層の反射膜側の面上に平坦化膜を形成する場合の波長変換素子の製造工程を示す垂直断面図である。FIG. 7B is a vertical cross-sectional view showing the manufacturing process of the wavelength conversion element when a planarization film is formed on the surface of the wavelength conversion layer on the reflection film side. 図７Ｃは、波長変換層の反射膜側の面上に平坦化膜を形成する場合の波長変換素子の製造工程を示す垂直断面図である。FIG. 7C is a vertical cross-sectional view illustrating the manufacturing process of the wavelength conversion element when a planarization film is formed on the surface of the wavelength conversion layer on the reflection film side. 図７Ｄは、波長変換層の反射膜側の面上に平坦化膜を形成する場合の波長変換素子の製造工程を示す垂直断面図である。FIG. 7D is a vertical cross-sectional view illustrating the manufacturing process of the wavelength conversion element when a planarization film is formed on the surface of the wavelength conversion layer on the reflection film side. 図７Ｅは、波長変換層の反射膜側の面上に平坦化膜を形成する場合の波長変換素子の製造工程を示す垂直断面図である。FIG. 7E is a vertical cross-sectional view illustrating the manufacturing process of the wavelength conversion element when a planarization film is formed on the surface of the wavelength conversion layer on the reflection film side. 図７Ｆは、波長変換層の反射膜側の面上に平坦化膜を形成する場合の波長変換素子の製造工程を示す垂直断面図である。FIG. 7F is a vertical cross-sectional view illustrating the manufacturing process of the wavelength conversion element in the case where a planarizing film is formed on the surface of the wavelength conversion layer on the reflective film side. 図８は、第２の実施の形態に係る波長変換モジュールの垂直断面図である。FIG. 8 is a vertical sectional view of the wavelength conversion module according to the second embodiment.
〔第１の実施の形態〕
（波長変換部材の構成）
　図１Ａ、図１Ｂは、第１の実施の形態に係る波長変換部材１の斜視図である。波長変換部材１は、蛍光体の粒子群の焼結体からなり、固有の形状を有する。また、波長変換部材１の任意の切断面における空隙（気孔）の全体に対する面積比率は、０．６％以上、２５％以下の範囲内にあり、好ましくは、１％以上、１５％以下の範囲内にある。 [First Embodiment]
(Configuration of wavelength conversion member)
1A and 1B are perspective views of the wavelength conversion member 1 according to the first embodiment. The wavelength conversion member 1 is made of a sintered body of phosphor particle groups and has a unique shape. Moreover, the area ratio with respect to the whole space | gap (pore) in the arbitrary cut surfaces of the wavelength conversion member 1 is in the range of 0.6% or more and 25% or less, preferably in the range of 1% or more and 15% or less. Is in.
　波長変換部材１の形状は特に限定されないが、典型的には平板形状である。図１Ａ、図１Ｂに示される例では、波長変換部材１は平面形状が円形である平板形状を有する。 The shape of the wavelength conversion member 1 is not particularly limited, but is typically a flat plate shape. In the example shown in FIGS. 1A and 1B, the wavelength conversion member 1 has a flat plate shape with a circular planar shape.
　図１Ａは、励起光の一部と励起光を波長変換した蛍光との混合光を波長変換部材１から取り出す場合の模式図である。例えば、励起光が青色光であり、蛍光が黄色光である場合、白色光を波長変換部材１から取り出すことができる。図１Ｂは、励起光のほぼ全てを波長変換し、ほぼ蛍光のみを波長変換部材１から取り出す場合の模式図である。 FIG. 1A is a schematic diagram in the case where mixed light of a part of excitation light and fluorescence obtained by converting the wavelength of excitation light is extracted from the wavelength conversion member 1. For example, when the excitation light is blue light and the fluorescence is yellow light, white light can be extracted from the wavelength conversion member 1. FIG. 1B is a schematic diagram in the case where the wavelength of almost all of the excitation light is converted and only the fluorescence is extracted from the wavelength conversion member 1.
　なお、図１Ａ、図１Ｂに示される例では、励起光を反射して光を取り出す反射型の波長変換部材として波長変換部材１を用いているが、励起光を透過させて光を取り出す透過型の波長変換部材として用いることもできる。 In the example shown in FIGS. 1A and 1B, the wavelength conversion member 1 is used as a reflection type wavelength conversion member that reflects excitation light and extracts light, but is a transmission type that transmits excitation light and extracts light. It can also be used as a wavelength conversion member.
　図２Ａ、図２Ｂは、蛍光体からなる一般的な波長変換部材３０から発せられてレンズ３１に集光される蛍光の光路を模式的に示す図である。図２Ａ、図２Ｂの「Ｐ」は、励起光の照射位置を示す。 2A and 2B are diagrams schematically showing an optical path of fluorescence emitted from a general wavelength conversion member 30 made of a phosphor and condensed on a lens 31. FIG. “P” in FIGS. 2A and 2B indicates the irradiation position of the excitation light.
　図２Ａに示されるように、励起光の照射位置Ｐの近傍から発せられる蛍光３２は、レンズ３１により平行光として集光される。一方で、図２Ｂに示されるように、励起光の照射位置Ｐから離れた位置から発せられた蛍光３２は、レンズ３１により平行光として集光されず、光学系に有効に用いることができない。 As shown in FIG. 2A, the fluorescence 32 emitted from the vicinity of the excitation light irradiation position P is condensed by the lens 31 as parallel light. On the other hand, as shown in FIG. 2B, the fluorescence 32 emitted from a position away from the excitation light irradiation position P is not condensed as parallel light by the lens 31 and cannot be used effectively in the optical system.
　一般的に、蛍光体からなる波長変換部材においては、上述のように、気孔を含まない場合や気孔率が小さい場合、波長変換部材内において散乱が少ないために光が広範囲に拡がり、蛍光の出射される領域が大きくなる。この場合、図２Ｂに示されるように、光学系に有効に用いることができない光の量が増えるため、光学系との結合効率が低くなる。 In general, in the wavelength conversion member made of a phosphor, as described above, when the pores are not included or the porosity is small, light is spread in a wide range due to less scattering in the wavelength conversion member, and emission of fluorescence The area to be increased. In this case, as shown in FIG. 2B, since the amount of light that cannot be used effectively in the optical system increases, the coupling efficiency with the optical system decreases.
　また、吸収されずに反射等される励起光の一部と蛍光の混合光を白色光等として取り出す場合には、蛍光の出射される領域が大きくなると、励起光が射出される領域との差が生じ、取り出した光を遠方に照射したときに色割れが生じるという問題がある。 In addition, when extracting a part of the excitation light that is reflected without being absorbed and the mixed light of the fluorescence as white light or the like, the difference from the area where the excitation light is emitted becomes larger when the area where the fluorescence is emitted becomes larger. There is a problem that color breakage occurs when the extracted light is irradiated far away.
　波長変換部材１は、任意の切断面における空隙（気孔）の全体に対する面積比率が０．６％以上となるような量の気孔を含むことにより、波長変換部材１内において光を散乱させている。これにより、蛍光の出射される領域の拡大を抑え、光学系との結合効率を高めている。また、波長変換部材１が、任意の切断面における空隙（気孔）の全体に対する面積比率が１％以上となるような量の気孔を含むことにより、より効果的に光を散乱させ、光学系との結合効率をより高めることができる。 The wavelength conversion member 1 scatters light in the wavelength conversion member 1 by including pores in such an amount that the area ratio with respect to the entire voids (pores) in an arbitrary cut surface is 0.6% or more. . Thereby, the expansion of the region where the fluorescence is emitted is suppressed, and the coupling efficiency with the optical system is increased. Further, the wavelength conversion member 1 includes more pores in such an amount that the area ratio with respect to the entire voids (pores) in an arbitrary cut surface is 1% or more, so that the light is more effectively scattered, and the optical system The coupling efficiency can be further increased.
　ただし、気孔率が高すぎると、波長変換部材１の機械的な強度や熱伝導率が実用的でない程度まで低下する場合があるため、波長変換部材１の任意の切断面における空隙（気孔）の全体に対する面積比率は、２５％以下であり、好ましくは、１５％以下である。 However, if the porosity is too high, the mechanical strength and thermal conductivity of the wavelength conversion member 1 may be reduced to an impractical level. Therefore, voids (pores) in an arbitrary cut surface of the wavelength conversion member 1 may be reduced. The area ratio with respect to the whole is 25% or less, preferably 15% or less.
　図３は、波長変換部材１の一例の切断面のＳＥＭ（Scanning Electron Microscope）観察像である。図３に示される波長変換部材１は、組成式（Ｙ０．９９８Ｃｅ０．００２）３Ａｌ５Ｏ１２で表される組成を有する単結晶蛍光体の焼結体である。矢印で示される部分が空隙（気孔）であり、大部分を占める同一色の部分が蛍光体である。このように、波長変換部材１の任意の切断面における空隙の全体に対する面積比率は、ＳＥＭ観察などを用いて測定することができる。 FIG. 3 is an SEM (Scanning Electron Microscope) observation image of a cut surface of an example of the wavelength conversion member 1. The wavelength conversion member 1 shown in FIG. 3 is a sintered body of a single crystal phosphor having a composition represented by the composition formula (Y 0.998 Ce 0.002 ) 3 Al 5 O 12 . A portion indicated by an arrow is a void (a pore), and a portion of the same color that occupies most is a phosphor. Thus, the area ratio with respect to the whole space | gap in the arbitrary cut surfaces of the wavelength conversion member 1 can be measured using SEM observation.
　また、波長変換部材１は、蛍光体の粒子群から構成されるため、内部に粒界を有する。粒界は気孔と同様に光を散乱させるため、波長変換部材１の光学系との結合効率を向上させるために重要である。 Moreover, since the wavelength conversion member 1 is composed of a group of phosphor particles, it has a grain boundary inside. Since the grain boundary scatters light in the same manner as the pores, it is important for improving the coupling efficiency of the wavelength conversion member 1 with the optical system.
　また、波長変換部材１は、優れた内部量子効率を有する。例えば、波長変換部材１を構成する粒子状の蛍光体が組成式（Ｙ１－ｘ－ｙ－ｚＬｕｘＧｄｙＣｅｚ）３＋ａＡｌ５－ａＯ１２（０≦ｘ≦０．９９９４、０≦ｙ≦０．０６６９、０．０００２≦ｚ≦０．００６７、－０．０１６≦ａ≦０．３１５）で表される組成を有する単結晶体である場合、温度が２５℃、励起光のピーク波長が４５０ｎｍであるときの内部量子効率は０.９５以上であり、温度が３００℃、励起光のピーク波長が４５０ｎｍであるときの内部量子効率は０.９０以上である。 Moreover, the wavelength conversion member 1 has an excellent internal quantum efficiency. For example, the particulate phosphor constituting the wavelength conversion member 1 is composed of a composition formula (Y 1-xy-Z Lu x Gd y Ce z ) 3 + a Al 5-a O 12 (0 ≦ x ≦ 0.9994, 0 ≦ y ≦ 0.0669, 0.0002 ≦ z ≦ 0.0067, −0.016 ≦ a ≦ 0.315), the temperature is 25 ° C., the excitation light The internal quantum efficiency when the peak wavelength is 450 nm is 0.95 or more, the internal quantum efficiency is 0.90 or more when the temperature is 300 ° C. and the peak wavelength of the excitation light is 450 nm.
　また、波長変換部材１を構成する粒子状の蛍光体が組成式（Ｙ０．９９８Ｃｅ０．００２）３Ａｌ５Ｏ１２で表される組成を有する単結晶体である場合、温度が２５℃、励起光のピーク波長が４５０ｎｍであるときの内部量子効率は０．９９以上であり、温度が３００℃、励起光のピーク波長が４５０ｎｍであるときの内部量子効率は０．９０以上である。 When the particulate phosphor constituting the wavelength conversion member 1 is a single crystal having a composition represented by the composition formula (Y 0.998 Ce 0.002 ) 3 Al 5 O 12 , the temperature is 25 ° C. When the peak wavelength of the excitation light is 450 nm, the internal quantum efficiency is 0.99 or more, and when the temperature is 300 ° C. and the peak wavelength of the excitation light is 450 nm, the internal quantum efficiency is 0.90 or more.
　また、波長変換部材１を構成する粒子状の蛍光体が組成式（Ｌｕ０．９９８Ｃｅ０．００２）３Ａｌ５Ｏ１２で表される組成を有する単結晶体である場合、温度が２５℃、励起光のピーク波長が４５０ｎｍであるときの内部量子効率は０．９９以上であり、温度が３００℃、励起光のピーク波長が４５０ｎｍであるときの内部量子効率は０．９３以上である。 In addition, when the particulate phosphor constituting the wavelength conversion member 1 is a single crystal having a composition represented by the composition formula (Lu 0.998 Ce 0.002 ) 3 Al 5 O 12 , the temperature is 25 ° C. When the peak wavelength of the excitation light is 450 nm, the internal quantum efficiency is 0.99 or more, and when the temperature is 300 ° C. and the peak wavelength of the excitation light is 450 nm, the internal quantum efficiency is 0.93 or more.
　文献Solid-State Lighting Research and Development: Multi Year Program Plan March 2011 (Updated May 2011) P.69 の表 A1.3 によれば、内部量子効率（Quantum Yield (25°C) across the visible spectrum）の２０１０年の数値は０．９０であり、２０２０年の目標値が０．９５であることが記載されている。このことから、業界では、２年で０．０１程度の量子効率の向上が期待されていることがわかり、本実施の形態の蛍光体は、出願時において目標とされる数値に近い、又は超えた量子効率を有する優れた蛍光体であるといえる。 According to the document Solid-State Lighting Research and Development: Multi Year Program Plan March 2011 (Updated May 2011) P.69 Table A1.3, the internal quantum efficiency (Quantum Yield (25 ° C) across the visible spectrum) 2010 The numerical value of the year is 0.90, and it is described that the target value for 2020 is 0.95. From this, it can be seen that the quantum efficiency of about 0.01 is expected in the industry in two years, and the phosphor of the present embodiment is close to or exceeding the target value at the time of filing. It can be said that the phosphor has excellent quantum efficiency.
　上述のように、波長変換部材１は、３００℃という高温条件下においても高い内部量子効率を保つことができるため、例えば、励起光がレーザー光であるレーザープロジェクタやレーザーヘッドライトのように、単位面積当たりの輝度が極めて高い発光装置に用いられる波長変換部材として優れた機能を発揮することができる。 As described above, since the wavelength conversion member 1 can maintain high internal quantum efficiency even under a high temperature condition of 300 ° C., for example, a unit such as a laser projector or a laser headlight whose excitation light is laser light. An excellent function as a wavelength conversion member used in a light emitting device having extremely high luminance per area can be exhibited.
　また、放熱性を向上させるため、波長変換部材１の厚さは０．３ｍｍ以下であることが好ましい。具体例としては、プロジェクターやスポットライトなどの高輝度照明に用いるために、ＹＡＧ系単結晶蛍光体からなる波長変換部材１に２０Ｗ以上の青色レーザー光を直径３．０ｍｍ以下のスポット径で照射する場合、波長変換部材１の熱伝導率を考慮して、厚さは０．３ｍｍ以下であることが好ましい。また、車両のヘッドライトやフラッシュライトに用いるために、ＹＡＧ系単結晶蛍光体からなる波長変換部材１に２Ｗ以上の青色レーザー光を直径０．３００ｍｍ以下のスポット径で照射する場合、波長変換部材１の熱伝導率を考慮して、厚さは０．３ｍｍ以下であることが好ましい。また、加工中の割れを抑えるために、波長変換部材１の厚さは０．０５ｍｍ以上であることが好ましい。 In order to improve heat dissipation, the thickness of the wavelength conversion member 1 is preferably 0.3 mm or less. As a specific example, for use in high-luminance illumination such as projectors and spotlights, the wavelength conversion member 1 made of a YAG single crystal phosphor is irradiated with blue laser light of 20 W or more with a spot diameter of 3.0 mm or less. In this case, the thickness is preferably 0.3 mm or less in consideration of the thermal conductivity of the wavelength conversion member 1. Further, when irradiating the wavelength conversion member 1 made of a YAG single crystal phosphor with a blue laser beam of 2 W or more with a spot diameter of 0.300 mm or less for use in a vehicle headlight or flashlight, the wavelength conversion member In consideration of the thermal conductivity of 1, the thickness is preferably 0.3 mm or less. In order to suppress cracking during processing, the thickness of the wavelength conversion member 1 is preferably 0.05 mm or more.
（蛍光体の特徴）
　一般的に、単結晶蛍光体は多結晶蛍光体よりも温度の上昇に伴う蛍光強度の低下が少ない場合が多いため、波長変換部材１を構成する蛍光体は、単結晶蛍光体であることが好ましい。すなわち、波長変換部材１は、単結晶蛍光体の粒子群の焼結体からなることが好ましい。 (Characteristics of phosphor)
In general, since the single crystal phosphor often has a lower decrease in fluorescence intensity due to the temperature rise than the polycrystalline phosphor, the phosphor constituting the wavelength conversion member 1 may be a single crystal phosphor. preferable. That is, the wavelength conversion member 1 is preferably made of a sintered body of particle groups of single crystal phosphors.
　例えば、ＹＡＧ系単結晶蛍光体は、ＹＡＧ系多結晶蛍光体よりも温度の上昇に伴う蛍光強度の低下が少ない。蛍光強度の低下が少ないのは、内部量子効率の低下が少ないことによる。 For example, a YAG-based single crystal phosphor has a lower decrease in fluorescence intensity with an increase in temperature than a YAG-based polycrystalline phosphor. The decrease in fluorescence intensity is small because the decrease in internal quantum efficiency is small.
　また、波長変換部材１を構成する蛍光体は、特に限定されないが、温度特性に優れるＹＡＧ系蛍光体であることが好ましい。ＹＡＧ系蛍光体は、Ｙ３Ａｌ５Ｏ１２（ＹＡＧ）結晶を母結晶とする蛍光体である。 Further, the phosphor constituting the wavelength conversion member 1 is not particularly limited, but is preferably a YAG phosphor having excellent temperature characteristics. The YAG phosphor is a phosphor having a Y 3 Al 5 O 12 (YAG) crystal as a mother crystal.
　例えば、波長変換部材１を構成する蛍光体として、組成式（Ｙ１－ｘ－ｙ－ｚＬｕｘＧｄｙＣｅｚ）３＋ａＡｌ５－ａＯ１２（０≦ｘ≦０．９９９４、０≦ｙ≦０．０６６９、０．０００２≦ｚ≦０．００６７、－０．０１６≦ａ≦０．３１５）で表される組成を有するＹＡＧ系蛍光体、組成式（Ｙ０．９９８Ｃｅ０．００２）３Ａｌ５Ｏ１２で表される組成を有するＹＡＧ蛍光体、組成式（Ｌｕ０．９９８Ｃｅ０．００２）３Ａｌ５Ｏ１２で表される組成を有するＬｕＡＧ蛍光体を用いることができる。ここで、Ｌｕ、Ｇｄは、Ｙを置換する発光中心とならない成分である。Ｃｅは、Ｙを置換する発光中心となり得る成分（付活剤）である。 For example, the phosphors of the wavelength conversion member 1, the composition formula (Y 1-x-y- z Lu x Gd y Ce z) 3 + a Al 5-a O 12 (0 ≦ x ≦ 0.9994,0 ≦ y ≦ 0.0669, 0.0002 ≦ z ≦ 0.0067, −0.016 ≦ a ≦ 0.315), a YAG-based phosphor having a composition represented by the formula (Y 0.998 Ce 0.002 ) YAG phosphor having a composition represented by 3 Al 5 O 12, may be used LuAG phosphor having a composition represented by composition formula (Lu 0.998 Ce 0.002) 3 Al 5 O 12. Here, Lu and Gd are components that do not serve as the emission center for substituting Y. Ce is a component (activator) that can serve as a luminescent center for substituting Y.
　なお、上記の蛍光体の組成のうち、一部の原子は結晶構造上の異なる位置を占めることがある。また、上記の組成式における組成比のＯの値は１２と記述されるが、上記の組成は、不可避的に混入または欠損する酸素の存在により組成比のＯの値が僅かに１２からずれた組成も含む。また、組成式におけるａの値は、蛍光体の製造上、不可避的に変化する値であるが、－０．０１６≦ａ≦０．３１５程度の数値範囲内での変化は、蛍光体の物性にほとんど影響を及ぼさない。 In the above phosphor composition, some atoms may occupy different positions on the crystal structure. In addition, although the value of O in the composition ratio in the above composition formula is described as 12, the above composition is slightly deviated from 12 in the composition ratio due to the presence of inevitably mixed or missing oxygen. Also includes composition. Further, the value of a in the composition formula is a value that inevitably changes in the production of the phosphor, but the change within the numerical range of about −0.016 ≦ a ≦ 0.315 indicates the physical properties of the phosphor. Has little effect on
　Ｃｅの濃度を表す上記組成式におけるｚの数値の範囲が０．０００２≦ｚ≦０．００６７であるのは、ｚの数値が０．０００２よりも小さい場合は、Ｃｅ濃度が低すぎるために、励起光の吸収が小さくなり、外部量子効率が小さくなりすぎるという問題が生じ、０．００６７よりも大きい場合は、単結晶蛍光体のインゴットを育成する際にクラックやボイド等が生じ、結晶品質が低下する可能性が高くなるためである。また、ｚの数値が０．００１０以上であれば、波長変換部材１が薄くても十分に波長変換を行うことができるため、コストの低減や放熱性の向上をはかることができる。 The range of the numerical value of z in the above composition formula representing the concentration of Ce is 0.0002 ≦ z ≦ 0.0067 because when the numerical value of z is smaller than 0.0002, the Ce concentration is too low. The problem is that the absorption of excitation light becomes small and the external quantum efficiency becomes too small, and when it is larger than 0.0067, cracks and voids occur when growing an ingot of a single crystal phosphor, and the crystal quality is low. This is because there is a high possibility of a decrease. Moreover, if the numerical value of z is 0.0010 or more, wavelength conversion can be sufficiently performed even if the wavelength conversion member 1 is thin, so that cost reduction and heat dissipation can be improved.
　また、波長変換部材１を構成する蛍光体は、ＹＡＧ系蛍光体である場合、Ｂａ、Ｓｒ等の２族元素及びＦ、Ｂｒ等の１７族元素を含まず、高い純度を有することが好ましい。これにより高輝度で高寿命な蛍光体を実現できる。 Further, when the phosphor constituting the wavelength conversion member 1 is a YAG phosphor, it does not contain a group 2 element such as Ba and Sr and a group 17 element such as F and Br, and preferably has high purity. As a result, a phosphor with high brightness and long life can be realized.
　波長変換部材１を構成する蛍光体は、単結晶蛍光体である場合、例えば、ＣＺ法（Czochralski Method）、ＥＦＧ法（Edge Defined Film Fed Growth Method）、ブリッジマン法、ＦＺ法（Floating Zone Method）、ベルヌーイ法等の液相成長法によって得ることができる。そして、単結晶蛍光体の粒子群は、これらの液相成長法により得られた単結晶蛍光体のインゴットを粉砕することにより得られる。 When the phosphor constituting the wavelength conversion member 1 is a single crystal phosphor, for example, CZ method (Czochralski Method), EFG method (Edge Film Fed Growth Method), Bridgman method, FZ method (Floating Zone Method) It can be obtained by a liquid phase growth method such as Bernoulli method. The single crystal phosphor particles can be obtained by pulverizing the single crystal phosphor ingots obtained by the liquid phase growth method.
　波長変換部材１を構成する蛍光体の粒子群が単結晶蛍光体の粒子群である場合、その粒径（Ｄ５０）は、３μｍ以上、３０μｍ以下の範囲内にあることが好ましく、３μｍ以上、１５μｍ以下の範囲内にあることがより好ましい。ここで、Ｄ５０とは、累積分布における５０ｖｏｌ％のときの粒径をいう。 When the phosphor particle group constituting the wavelength conversion member 1 is a single crystal phosphor particle group, the particle diameter (D50) is preferably in the range of 3 μm to 30 μm, preferably 3 μm to 15 μm. It is more preferable to be within the following range. Here, D50 refers to the particle size at 50 vol% in the cumulative distribution.
　粒径（Ｄ５０）が３０μｍ以下である場合、焼結が進み易くなり、また、空孔が小さくなるため、空孔による波長変換部材１の熱伝導率の低下を抑制することができる。熱伝導率が高ければ、強度の大きな励起光を照射することができる。さらに、粒径（Ｄ５０）が１５μｍ以下である場合、波長変換部材１の密度がより高まり、熱伝導率が向上する。一方、粒径（Ｄ５０）が３μｍより小さい場合、焼結は進みやすいが、空孔が少なくなりすぎるため、波長変換部材１の内部での光の散乱が減り、配光特性がランバーシアン配光から離れる。そのため、波長変換部材１と光学系との結合効率が低下する。また、粒径が小さ過ぎると、波長変換効率や熱伝導率が低下するという問題も生じる。 When the particle diameter (D50) is 30 μm or less, the sintering easily proceeds and the pores become small, so that a decrease in the thermal conductivity of the wavelength conversion member 1 due to the pores can be suppressed. If the thermal conductivity is high, high intensity excitation light can be irradiated. Furthermore, when the particle size (D50) is 15 μm or less, the density of the wavelength conversion member 1 is further increased, and the thermal conductivity is improved. On the other hand, when the particle size (D50) is smaller than 3 μm, the sintering is easy to proceed, but since the number of pores is too small, light scattering inside the wavelength conversion member 1 is reduced, and the light distribution characteristic is Lambertian light distribution. Get away from. Therefore, the coupling efficiency between the wavelength conversion member 1 and the optical system is reduced. Moreover, when a particle size is too small, the problem that wavelength conversion efficiency and heat conductivity fall will also arise.
　なお、ＹＡＧ多結晶蛍光体は、Ｙ２Ｏ３、Ａｌ２Ｏ３、ＣｅＯ２等の酸化物粉末原料を固相反応によって合成するため、１５～２０μｍ程度以上に大きな粒子径の蛍光体を製造することが困難である。一方、単結晶ＹＡＧ蛍光体は、融液成長した単結晶蛍光体のインゴットを粉砕して作製するため、１００μｍ以上の粒径のものも得ることができる。 Since YAG polycrystalline phosphors synthesize oxide powder raw materials such as Y 2 O 3 , Al 2 O 3 , and CeO 2 by solid phase reaction, they produce phosphors with a particle size larger than about 15 to 20 μm. Difficult to do. On the other hand, since the single crystal YAG phosphor is produced by pulverizing an ingot of a single crystal phosphor that has been melt-grown, a single crystal YAG phosphor having a particle diameter of 100 μm or more can be obtained.
　波長変換部材１は、単結晶蛍光体の粒子群から構成される場合であっても、蛍光体の封止材やバインダーを含まない。通常、封止材やバインダーは単結晶蛍光体よりも熱伝導率が低く、これらを用いることにより波長変換部材の放熱性が低下する。 The wavelength conversion member 1 does not include a phosphor sealing material or a binder even when the wavelength conversion member 1 is composed of a single crystal phosphor particle group. Usually, the sealing material and the binder have a lower thermal conductivity than the single crystal phosphor, and the heat dissipation of the wavelength conversion member is lowered by using these.
〔波長変換部材の製造〕
　単結晶蛍光体の粒子群から構成される波長変換部材１を製造する場合、単結晶蛍光体のインゴットを粉砕することにより得られる単結晶蛍光体の粒子群に圧力を加えて固形化し、焼結することにより、単結晶蛍光体の粒子群の焼結体を得る。単結晶蛍光体の粒子群の固形化、焼結には、ＳＰＳ（Spark Plasma Sintering）法やＣＩＰ（Cold Isostatic Pressing）法を用いることができる。 [Manufacture of wavelength conversion member]
When manufacturing the wavelength conversion member 1 composed of single crystal phosphor particles, the single crystal phosphor particles obtained by pulverizing the single crystal phosphor ingot are solidified by applying pressure to the single crystal phosphor particles. By doing so, a sintered body of the single crystal phosphor particle group is obtained. A SPS (Spark Plasma Sintering) method or a CIP (Cold Isostatic Pressing) method can be used for solidifying and sintering the particle group of the single crystal phosphor.
　また、多結晶蛍光体により構成される波長変換部材１を製造する場合は、混合した原料をＳＰＳ法やＣＩＰ法を用いて固相反応させ、焼結させることにより、所定の形状を有する多結晶蛍光体の粒子群の焼結体を得る。例えば、ＹＡＧ系単結晶蛍光体の粒子群の焼結体を製造するためには、原料であるＹ２Ｏ３、Ｌｕ２Ｏ３、Ｇｄ２Ｏ３、Ａｌ２Ｏ３、ＣｅＯ２の粉末をガーネット組成に合わせた量で混合して、固相反応させる。 Moreover, when manufacturing the wavelength conversion member 1 comprised with a polycrystalline fluorescent substance, the mixed raw material is solid-phase-reacted using SPS method or CIP method, and is sintered, and thereby has a predetermined shape. A sintered body of phosphor particles is obtained. For example, in order to manufacture a sintered body of a YAG-based single crystal phosphor particle group, powders of Y 2 O 3 , Lu 2 O 3 , Gd 2 O 3 , Al 2 O 3 , and CeO 2 as raw materials are used. Mix in an amount that matches the garnet composition and allow a solid phase reaction.
　波長変換部材１の空隙の割合を、任意の切断面における空隙の全体に対する面積比率が０．６％以上、２５％以下の範囲内、好ましくは１％以上、１５％以下の範囲内に納めるためには、蛍光体が単結晶である場合も、多結晶である場合も、蛍光体粒子の粒径、焼結工程における圧力、焼成温度、焼成時間などにより空隙の割合を制御する。 In order to keep the ratio of the gap of the wavelength conversion member 1 within the range of 0.6% or more and 25% or less, preferably 1% or more and 15% or less, of the area ratio to the whole of the gap at an arbitrary cut surface. In the case where the phosphor is a single crystal or a polycrystal, the void ratio is controlled by the particle size of the phosphor particles, the pressure in the sintering process, the firing temperature, the firing time, and the like.
　例えば、蛍光体粒子の粒径が大きいほど空隙が大きくなるため、空隙の割合が増える。蛍光体粒子の粒径は、例えば、遊星ボールミルを用いた粒子の微粉砕処理の処理時間によって制御することができる。また、焼結工程における圧力が小さいと、空隙が潰れずに残るため、空隙の割合が大きくなる。また、焼結工程において焼成温度を高くする、又は焼成時間を長くすることにより、より焼成が進むため、空隙が小さくなり、空隙の割合が小さくなる。 For example, the larger the particle size of the phosphor particles, the larger the voids, so the void ratio increases. The particle size of the phosphor particles can be controlled by, for example, the processing time of the fine pulverization processing of the particles using a planetary ball mill. On the other hand, when the pressure in the sintering process is small, the voids remain without being crushed, and the void ratio increases. Further, by increasing the firing temperature or lengthening the firing time in the sintering step, the firing proceeds further, so the voids are reduced and the void ratio is reduced.
　以下に、より具体的な波長変換部材１の製造方法の例を示す。 Hereinafter, a more specific example of the manufacturing method of the wavelength conversion member 1 will be shown.
　図４は、実施の形態に係る波長変換部材１の製造工程の一例を示すフローチャートである。図４は、一例として、ＹＡＧ系単結晶蛍光体の粒子群の焼結体からなる波長変換部材１の製造工程の流れを示す。 FIG. 4 is a flowchart showing an example of a manufacturing process of the wavelength conversion member 1 according to the embodiment. FIG. 4 shows, as an example, the flow of a manufacturing process of the wavelength conversion member 1 made of a sintered body of YAG-based single crystal phosphor particles.
　まず、単結晶蛍光体を育成して、インゴットを得る（ステップＳ１）。出発原料として、高純度（９９．９９％以上）のＹ２Ｏ３、Ｌｕ２Ｏ３、Ｇｄ２Ｏ３、ＣｅＯ２、Ａｌ２Ｏ３の粉末を用意し、乾式混合を行い、混合粉末を得る。なお、Ｙ、Ｌｕ、Ｇｄ、Ｃｅ、及びＡｌの原料粉末は、上記のものに限られない。また、Ｌｕ又はＧｄを含まない単結晶蛍光体を製造する場合は、それらの原料粉末は用いない。 First, a single crystal phosphor is grown to obtain an ingot (step S1). As starting materials, high-purity (99.99% or more) Y 2 O 3 , Lu 2 O 3 , Gd 2 O 3 , CeO 2 , and Al 2 O 3 powders are prepared, dry mixed, and the mixed powders are prepared. obtain. The raw material powders of Y, Lu, Gd, Ce, and Al are not limited to the above. Further, when producing a single crystal phosphor containing no Lu or Gd, those raw material powders are not used.
　図５は、ＣＺ法による単結晶蛍光体インゴットの引き上げを模式的に示す断面図である。結晶育成装置４０は、イリジウム製のルツボ４１と、ルツボ４１を収容するセラミックス製の筒状容器４２と、筒状容器４２の周囲に巻回される高周波コイル４３とを主として備えている。 FIG. 5 is a cross-sectional view schematically showing pulling of the single crystal phosphor ingot by the CZ method. The crystal growing apparatus 40 mainly includes an iridium crucible 41, a ceramic cylindrical container 42 that houses the crucible 41, and a high-frequency coil 43 that is wound around the cylindrical container 42.
　得られた混合粉末をルツボ４１内に入れ、窒素雰囲気中で高周波コイル４３により３０ｋＷの高周波エネルギーをルツボ４１に供給して誘導電流を生じさせ、ルツボ４１を加熱する。これにより混合粉末を溶融し、融液５０を得る。 The obtained mixed powder is put in the crucible 41, and high-frequency energy of 30 kW is supplied to the crucible 41 in the nitrogen atmosphere by the high-frequency coil 43 to generate an induced current, and the crucible 41 is heated. As a result, the mixed powder is melted to obtain a melt 50.
　次に、ＹＡＧ系単結晶蛍光体である種結晶５１の先端を融液５０に接触させた後、１０ｒｐｍの回転数で回転させながら１ｍｍ／ｈ以下の引き上げ速度で引き上げ、１９６０℃以上の引き上げ温度で＜１１１＞方向に単結晶蛍光体インゴット５２を育成する。この単結晶蛍光体インゴット５２の育成は、筒状容器４２内に毎分２Ｌの流量で窒素を流し込み、大気圧下、窒素雰囲気中で行われる。 Next, after the tip of the seed crystal 51, which is a YAG-based single crystal phosphor, is brought into contact with the melt 50, it is pulled up at a pulling speed of 1 mm / h or less while rotating at a rotation speed of 10 rpm, and a pulling temperature of 1960 ° C. or higher. The single crystal phosphor ingot 52 is grown in the <111> direction. The single crystal phosphor ingot 52 is grown by flowing nitrogen into the cylindrical container 42 at a flow rate of 2 L / min in a nitrogen atmosphere under atmospheric pressure.
　こうして、例えば、直径約２．５ｃｍ、長さ約１０ｃｍの単結晶蛍光体インゴット５２が得られる。 Thus, for example, a single crystal phosphor ingot 52 having a diameter of about 2.5 cm and a length of about 10 cm is obtained.
　次に、単結晶蛍光体のインゴットを粉砕し、粒子化する（ステップＳ２）。まず、単結晶蛍光体のインゴットを、急加熱、急冷却することにより粗く粉砕し、１～３ｍｍ程度の粒径を有する単結晶蛍光体の粒子群を得る。急加熱は、水素・酸素混合ガスバーナーを用いて実施することができる。また、急冷却は、水冷によって実施することができる。 Next, the single crystal phosphor ingot is pulverized into particles (step S2). First, an ingot of a single crystal phosphor is coarsely pulverized by rapid heating and rapid cooling to obtain a single crystal phosphor particle group having a particle size of about 1 to 3 mm. The rapid heating can be performed using a hydrogen / oxygen mixed gas burner. The rapid cooling can be performed by water cooling.
　続けて、遊星ボールミルを用いて粒子群を微粉砕した後、乾燥させる。これにより、粒子群の粒径（Ｄ５０）が３μｍ以上、３０μｍ以下の範囲内、より好ましくは３μｍ以上、１５μｍ以下の範囲内とすることができる。 Next, the particles are pulverized using a planetary ball mill and then dried. Thereby, the particle size (D50) of the particle group can be in the range of 3 μm or more and 30 μm or less, more preferably in the range of 3 μm or more and 15 μm or less.
　次に、単結晶蛍光体の粒子群に圧力を加えて固形化する（ステップＳ３）。固形化の方法は特に限定されず、例えば、ＳＰＳ法、ＣＩＰ法などを用いることができる。また、シート成形やスリップキャスト法により固形化を施してもよい。これらの方法を用いる場合、粒子群をウエハ上に保持するために有機バインダーが必要となるが、この有機バインダーは工程内で除去することができる。 Next, the single crystal phosphor particles are solidified by applying pressure (step S3). The solidification method is not particularly limited, and for example, an SPS method, a CIP method, or the like can be used. Further, solidification may be performed by sheet molding or slip casting. When these methods are used, an organic binder is required to hold the particle group on the wafer, and this organic binder can be removed in the process.
　固形化の際に粒子群に印加する圧力の大きさは、粒子群を固形状に保持できる程度の大きさであり、固形化方法による。例えば、ＣＩＰ法を用いる場合は、１００ＭＰａ以上であることが好ましい。 The magnitude of pressure applied to the particle group during solidification is large enough to hold the particle group in a solid state, and depends on the solidification method. For example, when the CIP method is used, the pressure is preferably 100 MPa or more.
　次に、固形化した単結晶蛍光体の粒子群を焼結する（ステップＳ４）。焼結を実施することにより、固形化した単結晶蛍光体の粒子群の機械的強度が向上し、また、内部量子効率が向上する。焼結のための熱処理の温度や保持時間は、焼結方法による。 Next, the solidified single crystal phosphor particles are sintered (step S4). By carrying out the sintering, the mechanical strength of the solidified single crystal phosphor particles is improved, and the internal quantum efficiency is improved. The temperature and holding time of the heat treatment for sintering depends on the sintering method.
　また、焼結は、アルゴン雰囲気下で実施される。焼結をアルゴン雰囲気下で実施する場合、大気、酸素雰囲気、窒素雰囲気、又はＡｒ９７．５％と水素２．５％の混合ガス雰囲気下で実施する場合よりも、内部量子効率の増加量が大きいことが本発明者らにより確かめられている。 Also, sintering is performed under an argon atmosphere. When the sintering is performed in an argon atmosphere, the amount of increase in internal quantum efficiency is larger than when the sintering is performed in an atmosphere of air, oxygen, nitrogen, or a mixed gas of Ar 97.5% and hydrogen 2.5%. It has been confirmed by the present inventors.
　焼結のための熱処理の温度や保持時間は、単結晶蛍光体の種類や焼結方法による。例えば、単結晶蛍光体がＹＡＧ系単結晶蛍光体であって、焼成炉内で焼結を実施する場合は、熱処理の温度は１６５０℃以上、１８５０℃以下の範囲内にあることが好ましい。また、目標温度に達してからの保持時間は１時間以上、１０時間以下の範囲内にあることが好ましい。 The temperature and holding time of the heat treatment for sintering depend on the type of single crystal phosphor and the sintering method. For example, when the single crystal phosphor is a YAG single crystal phosphor and sintering is performed in a firing furnace, the temperature of the heat treatment is preferably in the range of 1650 ° C. or higher and 1850 ° C. or lower. The holding time after reaching the target temperature is preferably in the range of 1 hour or more and 10 hours or less.
　熱処理の温度が１６５０℃より低い場合は、焼結に時間がかかる上に、焼結ムラを生じやすく、１８５０℃を越える場合は、蛍光体が溶融するおそれがある。保持時間が１時間より短い場合は、焼結が不十分になることがあり、また１０時間より長い場合は、焼結が進み過ぎて粒成長が進んだ結果、粒径の均一性が失われる。 When the temperature of the heat treatment is lower than 1650 ° C., it takes a long time to sinter, and uneven sintering is likely to occur. When the temperature exceeds 1850 ° C., the phosphor may melt. If the holding time is shorter than 1 hour, sintering may be insufficient, and if it is longer than 10 hours, uniformity of grain size is lost as a result of excessive sintering and grain growth. .
　なお、ステップＳ３の固形化にＳＰＳ法を用いた場合、ステップＳ４の焼成もＳＰＳ装置内で連続的に行われる。具体的には、例えば、単結晶蛍光体がＹＡＧ系単結晶蛍光体である場合、単結晶蛍光体の粒子群に３０ＭＰａ以上の圧力を印加した状態で、１５３０℃～１６００℃の熱処理を施す。 In addition, when SPS method is used for solidification of step S3, baking of step S4 is also continuously performed in the SPS apparatus. Specifically, for example, when the single crystal phosphor is a YAG single crystal phosphor, heat treatment at 1530 ° C. to 1600 ° C. is performed in a state where a pressure of 30 MPa or more is applied to the particle group of the single crystal phosphor.
　圧力が３０ＭＰａより小さい場合、焼結が進みにくく、そのために空孔が増える。このため、波長変換部材１の熱伝導率が低下したり、波長変換部材１への励起光の侵入が妨げられたりなどの問題が生じる。また、熱処理温度が１５３０℃より低い場合、焼結に時間がかかる上に、焼結ムラを生じやすく、１６００℃を越えると蛍光体が溶融するおそれがある。 When the pressure is less than 30 MPa, sintering is difficult to proceed, and the number of pores increases accordingly. For this reason, problems such as a decrease in the thermal conductivity of the wavelength conversion member 1 and an intrusion of excitation light into the wavelength conversion member 1 occur. Further, when the heat treatment temperature is lower than 1530 ° C., it takes time to sinter, and sintering unevenness is likely to occur, and if it exceeds 1600 ° C., the phosphor may melt.
　このとき、温度の上昇に伴って、単結晶蛍光体の粒子群の密度が大きくなり、単結晶蛍光体の粒子群に圧力を加えるピストンが変位する。目標温度に達して、ピストンの変位量がほぼ零になってから、所定の時間保持する。この保持時間は、３０秒以上、３分以下の範囲内にあることが好ましい。３０秒より短い場合は焼結が不十分になることがあり、また３分より長いと焼結が進み過ぎて粒径の均一性が失われる。 At this time, as the temperature rises, the density of the single crystal phosphor particle group increases, and the piston that applies pressure to the single crystal phosphor particle group displaces. After the target temperature is reached and the displacement of the piston becomes almost zero, it is held for a predetermined time. This holding time is preferably in the range of 30 seconds or more and 3 minutes or less. When the time is shorter than 30 seconds, the sintering may be insufficient. When the time is longer than 3 minutes, the sintering proceeds so much that the uniformity of the particle size is lost.
　単結晶蛍光体の粒子群に圧力を加えながら熱処理を施す方法としては、ＳＰＳ法の他にＨＩＰ（Hot Iso-static Press）法、ＶＰ（Vacuum Press）法などの方法があり、これらを用いてもよい。 In addition to the SPS method, there are methods such as the HIP (Hot Iso-static Press) method and the VP (Vacuum Press) method in addition to the SPS method. Also good.
　次に、単結晶蛍光体の粒子群の焼結体をスライスして、ウエハ状の焼結体を得る（ステップＳ５）。スライスは、マルチワイヤーソーなどを用いて実施することができる。 Next, the sintered body of the single crystal phosphor particle group is sliced to obtain a wafer-like sintered body (step S5). Slicing can be performed using a multi-wire saw or the like.
　ウエハ状の焼結体の厚さは、薄すぎるとスライスした際に割れが発生して歩留まりが低下するおそれがある。この観点からは、ウエハ状の焼結体の厚さは、０.１５ｍｍ以上であることが好ましい。また、厚すぎるとスライスにより切り出せる枚数が減るため、結果としてコストが増加する。この観点からは、ウエハ状の焼結体の厚さは、１.０ｍｍ以下であることが好ましい。 If the thickness of the wafer-like sintered body is too thin, cracking may occur when slicing and the yield may be reduced. From this viewpoint, the thickness of the wafer-like sintered body is preferably 0.15 mm or more. On the other hand, if it is too thick, the number of sheets that can be cut out by slicing decreases, resulting in an increase in cost. From this viewpoint, the thickness of the wafer-like sintered body is preferably 1.0 mm or less.
　次に、ウエハ状の単結晶蛍光体の粒子群の焼結体にアニール処理を施す（ステップＳ６）。アニール処理を実施することにより、単結晶蛍光体の粒子群の焼結体の内部量子効率が向上する。 Next, annealing treatment is performed on the sintered body of the particle group of the wafer-like single crystal phosphor (step S6). By carrying out the annealing treatment, the internal quantum efficiency of the sintered body of the single crystal phosphor particle group is improved.
　アニール処理の温度が低すぎる場合や、時間が短すぎる場合は、単結晶蛍光体の粒子群の焼結体の量子効率が十分に向上しない。また、アニール処理の温度が高すぎると装置の負荷が大きくなり、極端に高くすると、焼結体が溶けてしまう。また、アニール処理の時間は長い方が量子効率を高くする観点では好ましいが、長くし過ぎるとコストが増加するという問題がある。このため、アニール処理の温度は、１４５０℃以上、１６００℃以下の範囲内にあることが好ましい。また、アニール処理の時間は、５時間以上であることが好ましい。また、アニール処理の時間が１５時間を超えると単結晶蛍光体の粒子群の焼結体の内部量子効率の増加量にほとんど変化がなく、また、アニール処理の時間が長くなるほどコストが増加するため、アニール処理の時間は１５時間以下であることが好ましい。 When the annealing temperature is too low or the time is too short, the quantum efficiency of the sintered body of the single crystal phosphor particle group is not sufficiently improved. Moreover, if the temperature of annealing treatment is too high, the load of an apparatus will become large, and if it raises extremely, a sintered compact will melt | dissolve. In addition, a longer annealing time is preferable from the viewpoint of increasing the quantum efficiency, but there is a problem in that the cost increases if the annealing time is too long. For this reason, it is preferable that the temperature of an annealing process exists in the range of 1450 degreeC or more and 1600 degrees C or less. The annealing treatment time is preferably 5 hours or longer. Further, when the annealing time exceeds 15 hours, there is almost no change in the amount of increase in the internal quantum efficiency of the sintered body of the single crystal phosphor particle group, and the cost increases as the annealing time becomes longer. The annealing treatment time is preferably 15 hours or less.
　また、アニール処理は、アルゴン雰囲気下で実施される。アニール処理をアルゴン雰囲気下で実施する場合、大気、酸素雰囲気、窒素雰囲気、又はＡｒ９７．５％と水素２．５％の混合ガス雰囲気下で実施する場合よりも、内部量子効率の増加量が大きいことが本発明者らにより確かめられている。 Also, the annealing process is performed in an argon atmosphere. When the annealing treatment is performed in an argon atmosphere, the amount of increase in internal quantum efficiency is larger than that in the atmosphere, oxygen atmosphere, nitrogen atmosphere, or a mixed gas atmosphere of Ar 97.5% and hydrogen 2.5%. It has been confirmed by the present inventors.
　次に、ウエハ状の単結晶蛍光体の粒子群の焼結体に研磨処理を施す（ステップＳ７）。研磨処理は、例えば、研削、ダイヤモンドスラリー研磨、ＣＭＰ（Chemical Mechanical Polishing）などの組み合わせにより実施される。研磨処理は、目的の波長変換部材１の厚さ（好ましくは０．０５ｍｍ以上０．３ｍｍ以下）が得られるまで実施される。 Next, the sintered body of the particle group of the wafer-like single crystal phosphor is subjected to polishing treatment (step S7). The polishing process is performed, for example, by a combination of grinding, diamond slurry polishing, CMP (Chemical Mechanical Polishing), and the like. The polishing treatment is performed until the desired wavelength conversion member 1 thickness (preferably 0.05 mm or more and 0.3 mm or less) is obtained.
　以上の工程を経て、ＹＡＧ系単結晶蛍光体の粒子群の焼結体からなる、ウエハ形状の波長変換部材１が得られる。 Through the above steps, a wafer-shaped wavelength conversion member 1 made of a sintered body of YAG-based single crystal phosphor particles is obtained.
〔第２の実施の形態〕
（波長変換素子の構成）
　図６は、第２の実施の形態に係る波長変換素子１０の垂直断面図である。波長変換素子１０は、第１の実施の形態に係る波長変換部材１からなる波長変換層１１と、波長変換層１１の光取り出し側の反対側（以下、裏側という）の面上に形成された反射膜１２と、反射膜１２の裏側の面上に形成された保護膜１３と、保護膜１３の裏側の面上に形成されたパッドメタル１４と、波長変換層１１の光取り出し側の面上に形成された反射防止膜１５と、を備える。 [Second Embodiment]
(Configuration of wavelength conversion element)
FIG. 6 is a vertical sectional view of the wavelength conversion element 10 according to the second embodiment. The wavelength conversion element 10 is formed on the surface of the wavelength conversion layer 11 including the wavelength conversion member 1 according to the first embodiment and the opposite side of the light extraction side of the wavelength conversion layer 11 (hereinafter referred to as the back side). Reflective film 12, protective film 13 formed on the back surface of reflective film 12, pad metal 14 formed on the back surface of protective film 13, and light extraction side surface of wavelength conversion layer 11 And an antireflection film 15 formed on the substrate.
　波長変換層１１は、波長変換部材１からなる。すなわち、波長変換層１１は、蛍光体の粒子群の焼結体からなり、波長変換層１１の任意の切断面における空隙の全体に対する面積比率は、０．６％以上、２５％以下の範囲内にあり、好ましくは、１％以上、１５％以下の範囲内にある。 The wavelength conversion layer 11 includes the wavelength conversion member 1. That is, the wavelength conversion layer 11 is made of a sintered body of phosphor particle groups, and the area ratio with respect to the entire voids in an arbitrary cut surface of the wavelength conversion layer 11 is in the range of 0.6% or more and 25% or less. Preferably, it exists in the range of 1% or more and 15% or less.
　また、波長変換層１１の厚さも、波長変換部材１と同様に、０．０５０以上、０．３ｍｍ以下の範囲内にあることが好ましい。 Also, the thickness of the wavelength conversion layer 11 is preferably in the range of 0.050 or more and 0.3 mm or less, similarly to the wavelength conversion member 1.
　反射膜１２は、例えば、銀、銀合金、アルミニウムなどの反射率の高い金属からなる金属膜、誘電体多層膜、又はその組合せである。誘電体多層膜は、高屈折率（ｎ＝２．０以上）の膜と低屈折率（ｎ＝１．５以下）の膜の多層積層膜であり、高屈折率膜の材料としては、ＴｉＯ２、ＺｒＯ２、ＺｎＯなど、低屈折率膜の材料としては、ＳｉＯ２、ＣａＦ２、ＭｇＦ２などを用いることができる。反射膜１２の反射率は、波長変換層１１側からの光の波長（例えば４５０～７００ｎｍ）に対する平均反射率が９０以上であることが好ましい。 The reflective film 12 is, for example, a metal film made of a highly reflective metal such as silver, a silver alloy, or aluminum, a dielectric multilayer film, or a combination thereof. The dielectric multilayer film is a multilayer laminated film of a film having a high refractive index (n = 2.0 or more) and a film having a low refractive index (n = 1.5 or less). The material of the high refractive index film is TiO 2. As a material for the low refractive index film such as 2 , ZrO 2 , or ZnO, SiO 2 , CaF 2 , MgF 2, or the like can be used. Regarding the reflectance of the reflective film 12, the average reflectance with respect to the wavelength of light from the wavelength conversion layer 11 side (for example, 450 to 700 nm) is preferably 90 or more.
　保護膜１３は、波長変換素子１０を半田実装する際に、反射膜１２に半田やパッドメタル１４が混ざり、反射膜１２の反射率が低下することを防ぐ。例えば、反射膜１２が金属（例えば、銀、アルミニウム、又はそれらの合金）からなる場合には、反射膜１２を保護するために保護膜１３は必要である。特に、反射膜１２に銀を用いる場合には、硫化現象を防止するために反射膜１２の側面を含めて保護膜１３で覆う必要がある。保護膜１３の材料は、熱的に安定な酸化物、窒化物、高融点金属などであることが好ましく、具体的には、ＳｉＯ２、ＳｉＮ、ＴｉＮ、ＡｌＮ、ＴｉＷ、Ｐｔなどを用いることができる。なお、反射膜１２が誘電体などの半田やパッドメタル１４によって浸食されにくい材料からなる場合には、波長変換素子１０は保護膜１３を含まなくてもよい。 When the wavelength conversion element 10 is solder-mounted, the protective film 13 prevents the reflective film 12 from being mixed with solder and pad metal 14, thereby reducing the reflectance of the reflective film 12. For example, when the reflective film 12 is made of metal (for example, silver, aluminum, or an alloy thereof), the protective film 13 is necessary to protect the reflective film 12. In particular, when silver is used for the reflective film 12, it is necessary to cover the side of the reflective film 12 with the protective film 13 in order to prevent the sulfidation phenomenon. The material of the protective film 13 is preferably a thermally stable oxide, nitride, refractory metal or the like, and specifically, SiO 2 , SiN, TiN, AlN, TiW, Pt or the like is used. it can. When the reflective film 12 is made of a material that is not easily eroded by a solder such as a dielectric or the pad metal 14, the wavelength conversion element 10 may not include the protective film 13.
　パッドメタル１４は、半田に対する濡れ性が高い構成を有する。例えば、反射膜１２側（保護膜１３側）からＴｉ／Ｎｉ／Ａｕ、Ｔｉ／Ｐｔ／Ａｕなどの積層膜構造を有する。 The pad metal 14 has a configuration with high wettability to solder. For example, it has a laminated film structure of Ti / Ni / Au, Ti / Pt / Au, etc. from the reflective film 12 side (protective film 13 side).
　反射防止膜１５は、励起光が波長変換素子１０に入射するときに表面で反射されることを抑制できる。反射防止膜１５は、可視光に対して透明な誘電体膜の単層膜又は多層膜からなる。なお、反射防止膜１５を設ける代わりに波長変換層１１の光取り出し側の面に凹凸を設けて、励起光の反射を抑えてもよい。また、波長変換層１１の光取り出し側の面に凹凸を設けた上で、さらに反射防止膜１５を設けてもよい。 The antireflection film 15 can suppress reflection of excitation light on the surface when the excitation light enters the wavelength conversion element 10. The antireflection film 15 is made of a single-layer film or a multilayer film of a dielectric film that is transparent to visible light. Instead of providing the antireflection film 15, unevenness may be provided on the light extraction side surface of the wavelength conversion layer 11 to suppress reflection of excitation light. In addition, an antireflection film 15 may be further provided after unevenness is provided on the light extraction side surface of the wavelength conversion layer 11.
　保護膜１３により精度よく反射膜１２を覆い、効果的に保護するためには、平坦な面上に反射膜１２及び保護膜１３を形成することが好ましい。また、反射膜１２が誘電体多層膜からなる場合には、高い反射率を実現するためには、各層の屈折率や厚さが設計通りになることが重要であり、平坦な面上に反射膜１２を形成することが好ましい。これらの理由から、気孔率が比較的高いために表面に凹凸を有する波長変換層１１の反射膜１２側の面上に平坦な膜を設け、その上に反射膜１２や保護膜１３を形成することが好ましい。 In order to cover the reflective film 12 with high accuracy and effectively protect the protective film 13, it is preferable to form the reflective film 12 and the protective film 13 on a flat surface. In addition, when the reflective film 12 is made of a dielectric multilayer film, it is important that the refractive index and thickness of each layer be as designed in order to achieve a high reflectance, and the reflection is performed on a flat surface. It is preferable to form the film 12. For these reasons, since the porosity is relatively high, a flat film is provided on the reflective film 12 side surface of the wavelength conversion layer 11 having irregularities on the surface, and the reflective film 12 and the protective film 13 are formed thereon. It is preferable.
　図７Ａ～図７Ｆは、波長変換層１１の反射膜１２側の面上に平坦化膜１６を形成する場合の波長変換素子１０の製造工程を示す垂直断面図である。なお、図７Ａ～図７Ｆにおいては、波長変換層１１の表面の凹凸を強調するため、気孔を極端に大きく表している。 7A to 7F are vertical sectional views showing the manufacturing process of the wavelength conversion element 10 when the planarization film 16 is formed on the surface of the wavelength conversion layer 11 on the reflective film 12 side. 7A to 7F, the pores are shown extremely large in order to emphasize the irregularities on the surface of the wavelength conversion layer 11.
　まず、図７Ａに示されるように、波長変換層１１の裏側の面上にＣＶＤ法、スパッタ法、蒸着法、ＳＯＧ（Spin on Glass）法などにより平坦化膜１６を形成する。平坦化膜１６は、ＳｉＯ２膜や、スクリーン印刷、塗布法などと焼成工程によって形成したガラス層などの可視光に対して透明な膜である。この段階では平坦化膜１６はまだ平坦化されておらず、波長変換層１１の表面の凹凸に応じた凹凸を有する。 First, as shown in FIG. 7A, a planarizing film 16 is formed on the back surface of the wavelength conversion layer 11 by a CVD method, a sputtering method, a vapor deposition method, an SOG (Spin on Glass) method, or the like. The flattening film 16 is a film transparent to visible light, such as a SiO 2 film, a glass layer formed by screen printing, a coating method, and a baking process. At this stage, the planarization film 16 has not yet been planarized, and has irregularities corresponding to the irregularities on the surface of the wavelength conversion layer 11.
　次に、図７Ｂに示されるように、平坦化膜１６に研削、ダイヤモンドスラリー研磨、ＣＭＰなどの平坦化処理を施し、平坦化する。これにより、平坦化膜１６の反射膜１２と接する面が平坦面となる。 Next, as shown in FIG. 7B, the flattening film 16 is flattened by performing a flattening process such as grinding, diamond slurry polishing, and CMP. As a result, the surface of the planarizing film 16 that contacts the reflective film 12 becomes a flat surface.
　平坦化膜１６は、波長変換層１１の表面の穴をより確実に埋めるために、比較的厚く形成して、それから平坦化処理を施すことが好ましい。一方、比較的厚く形成することが可能で、かつ可視光に対して透明な膜は、一般的に、熱伝導率が高くない。そのため、波長変換層１１で発生した熱を効率的にパッドメタル１４に接続されるヒートシンクなどへ逃がすために、平坦化処理により平坦化膜１６を平坦性を保てる範囲でなるべく薄くすることが好ましい。また、平坦化膜１６は平坦化層は透明で散乱性の無い膜であるため、平坦化膜１６が厚すぎると、平坦化膜１６を通して光が広がり、レンズとの結合効率が低下するおそれがある。これらの理由から、平坦化膜１６の厚さは、３０μｍ以下であることが好ましく、１０μｍ以下であることがより好ましい。 The planarization film 16 is preferably formed to be relatively thick and then subjected to a planarization process in order to fill the holes on the surface of the wavelength conversion layer 11 more reliably. On the other hand, a film that can be formed relatively thick and is transparent to visible light generally has a low thermal conductivity. Therefore, in order to efficiently release the heat generated in the wavelength conversion layer 11 to a heat sink or the like connected to the pad metal 14, it is preferable to make the planarizing film 16 as thin as possible within a range in which the planarity can be maintained. Further, since the planarizing film 16 is a transparent and non-scattering film, if the planarizing film 16 is too thick, light may spread through the planarizing film 16 and the coupling efficiency with the lens may be reduced. is there. For these reasons, the thickness of the planarizing film 16 is preferably 30 μm or less, and more preferably 10 μm or less.
　次に、図７Ｃに示されるように、平坦化された平坦化膜１６の上に、スパッタ法、蒸着法などにより反射膜１２を形成する。 Next, as shown in FIG. 7C, the reflective film 12 is formed on the flattened film 16 by the sputtering method, the vapor deposition method, or the like.
　次に、図７Ｄに示されるように、反射膜１２の表面及び側面を覆うように保護膜１３を形成する。 Next, as shown in FIG. 7D, a protective film 13 is formed so as to cover the surface and side surfaces of the reflective film 12.
　次に、図７Ｅに示されるように、保護膜１３の上に、スパッタ法、蒸着法などによりパッドメタル１４を形成する。また、必要に応じて波長変換層１１の光取り出し側の面上に反射防止膜１５を形成してもよい。 Next, as shown in FIG. 7E, a pad metal 14 is formed on the protective film 13 by sputtering, vapor deposition, or the like. Further, an antireflection film 15 may be formed on the light extraction side surface of the wavelength conversion layer 11 as necessary.
　次に、図７Ｆに示されるように、ブレードダイシングなどにより、個々の波長変換素子１０に個片化する。 Next, as shown in FIG. 7F, the individual wavelength conversion elements 10 are separated into pieces by blade dicing or the like.
　図８は、第２の実施の形態に係る波長変換モジュール２０の垂直断面図である。波長変換モジュール２０は、波長変換素子１０が半田によりヒートシンク２１に固定されたモジュールであり、波長変換素子１０のパッドメタル１４と、ヒートシンク２１とを半田２２を介して接続されている。なお、半田実装後は、半田２２とパッドメタル１４が混合されているため、パッドメタル１４を視認できなくなる場合がある。 FIG. 8 is a vertical sectional view of the wavelength conversion module 20 according to the second embodiment. The wavelength conversion module 20 is a module in which the wavelength conversion element 10 is fixed to the heat sink 21 with solder, and the pad metal 14 of the wavelength conversion element 10 and the heat sink 21 are connected via the solder 22. In addition, after solder mounting, since the solder 22 and the pad metal 14 are mixed, the pad metal 14 may not be visible.
　半田２２は、金属材料からなる方が、波長変換層１１で発生した熱を効率的に放熱できる。また、半田２２の融点が低すぎると、波長変換層１１の温度が上昇した際に、波長変換素子１０がヒートシンク２１から剥がれるおそれがある。また、半田２２の融点が高すぎると、波長変換素子１０の実装時の熱によって反射膜１２が劣化するおそれがある。これらの理由から、半田２２の材料としては、ＳｎＡｇＣｕ（ＳＡＣ）、ＡｕＳｎ、ＡｕＧｅ、ＡｕＳｉが好ましい。 The solder 22 made of a metal material can efficiently dissipate heat generated in the wavelength conversion layer 11. If the melting point of the solder 22 is too low, the wavelength conversion element 10 may be peeled off from the heat sink 21 when the temperature of the wavelength conversion layer 11 rises. Further, if the melting point of the solder 22 is too high, the reflective film 12 may be deteriorated by heat when the wavelength conversion element 10 is mounted. For these reasons, the material of the solder 22 is preferably SnAgCu (SAC), AuSn, AuGe, or AuSi.
　ヒートシンク２１は、波長変換層１１の温度を効率的に下げるためには、Ｃｕ、ＣｕＷ、ＣｕＭｏ、ＳｉＣ、ＡｌＮ、ダイヤモンドなどの熱伝導率が高い材料からなることが好ましい。さらに、波長変換層１１の割れを防止するため、ヒートシンク２１が波長変換層１１と同程度の線膨張係数を有することが好ましい。例えば、波長変換層１１がＹＡＧ系蛍光体の粒子群の焼結体からなる場合、上述の熱伝導率が高い材料のうち、波長変換層１１と同程度の線膨張係数を有するＣｕＷ又はＣｕＭｏがヒートシンク２１の材料として好ましい。 The heat sink 21 is preferably made of a material having high thermal conductivity such as Cu, CuW, CuMo, SiC, AlN, diamond, etc., in order to efficiently lower the temperature of the wavelength conversion layer 11. Furthermore, in order to prevent the wavelength conversion layer 11 from cracking, the heat sink 21 preferably has a linear expansion coefficient comparable to that of the wavelength conversion layer 11. For example, when the wavelength conversion layer 11 is made of a sintered body of a YAG phosphor particle group, CuW or CuMo having a linear expansion coefficient comparable to that of the wavelength conversion layer 11 among the above-described high thermal conductivity materials is used. It is preferable as a material for the heat sink 21.
（実施の形態の効果）
　上記第１の実施の形態によれば、光学系との結合効率に優れた波長変換部材１を提供することができる。また、上記第２の実施の形態によれば、その波長変換部材１からなる波長変換層１１を含む、光学系との結合効率に優れた波長変換素子１０、及び波長変換モジュール２０を提供することができる。 (Effect of embodiment)
According to the first embodiment, the wavelength conversion member 1 having excellent coupling efficiency with the optical system can be provided. Moreover, according to the said 2nd Embodiment, the wavelength conversion element 10 excellent in the coupling efficiency with an optical system including the wavelength conversion layer 11 which consists of the wavelength conversion member 1, and the wavelength conversion module 20 are provided. Can do.
　実施例１として、ＳＰＳ法を用いたＹＡＧ系単結晶蛍光体の粒子群の焼結体からなる波長変換部材１の製造方法の例を示す。 Example 1 shows an example of a method for producing a wavelength conversion member 1 made of a sintered body of a YAG-based single crystal phosphor particle group using an SPS method.
　まず、組成式（Ｙ０．９９８Ｃｅ０．００２）３Ａｌ５Ｏ１２で表される組成を有する単結晶蛍光体のインゴットをＣＺ法により育成した（ステップＳ１）。 First, an ingot of a single crystal phosphor having a composition represented by the composition formula (Y 0.998 Ce 0.002 ) 3 Al 5 O 12 was grown by the CZ method (step S1).
　次に、単結晶蛍光体インゴットを粉砕して粒子化した（ステップＳ２）。まず、単結晶蛍光体インゴットに水素・酸素混合ガスバーナーを用いた急加熱と水冷による急冷却を施して粗く粉砕し、１～３ｍｍ程度の粒径を有する単結晶蛍光体の粒子群を得た。続けて、およそ２時間、遊星ボールミルを用いて粒子群を微粉砕した後、粒子群を８０℃で１日乾燥させた。これにより、粒径（Ｄ５０）がおよそ５μｍの蛍光体単結晶の粒子群を得た。 Next, the single crystal phosphor ingot was pulverized into particles (step S2). First, the single crystal phosphor ingot was subjected to rapid heating using a hydrogen / oxygen mixed gas burner and rapid cooling by water cooling and coarsely pulverized to obtain a single crystal phosphor particle group having a particle size of about 1 to 3 mm. . Subsequently, after pulverizing the particle group using a planetary ball mill for about 2 hours, the particle group was dried at 80 ° C. for 1 day. Thus, a phosphor single crystal particle group having a particle size (D50) of about 5 μm was obtained.
　ここで、遊星ボールミルのボールとして、酸化アルミニウムからなるボールを用いた。また、遊星ボールミルを用いた微粉砕において、粗く粉砕された単結晶蛍光体粒子とボールとエタノールの体積比を１：１：１とした。 Here, a ball made of aluminum oxide was used as the ball of the planetary ball mill. Further, in the fine pulverization using a planetary ball mill, the volume ratio of the coarsely pulverized single crystal phosphor particles, the ball and ethanol was set to 1: 1: 1.
　次に、ＳＰＳ法により、単結晶蛍光体の粒子群の固形化及び焼結を実施し、焼結体を得た（ステップＳ３、Ｓ４）。まず、単結晶蛍光体の粒子群にプレプレスを施した後、ＳＰＳ装置内の内径φ２０ｍｍのカーボン冶具内に収容した。次に、ＳＰＳ装置内を真空引きした後、アルゴン雰囲気（１ａｔｍ）に置換した。次に、カーボンパンチを介してピストンでカーボン冶具内の単結晶蛍光体の粒子群に８０ＭＰａの圧力を加えた。次に、８０ＭＰａの圧力を加えた状態でカーボンパンチ及びカーボン冶具に電流を流し、単結晶蛍光体の粒子群を加熱した。 Next, solidification and sintering of the single crystal phosphor particles were carried out by the SPS method to obtain a sintered body (steps S3 and S4). First, the single crystal phosphor particles were pre-pressed and then housed in a carbon jig having an inner diameter of 20 mm in the SPS apparatus. Next, the SPS apparatus was evacuated and then replaced with an argon atmosphere (1 atm). Next, a pressure of 80 MPa was applied to the single crystal phosphor particles in the carbon jig with a piston through a carbon punch. Next, a current was passed through the carbon punch and the carbon jig while applying a pressure of 80 MPa to heat the particle group of the single crystal phosphor.
　加熱開始後、約１０分でカーボン冶具内部の温度が目標温度の１５７０℃に到達した。なお、カーボン冶具の側面には直径１ｍｍ、深さ２ｍｍの孔があけられており、パイロメータを使ってカーボン冶具内部の温度を測定することができる。 The temperature inside the carbon jig reached the target temperature of 1570 ° C. in about 10 minutes after the start of heating. A hole having a diameter of 1 mm and a depth of 2 mm is formed on the side surface of the carbon jig, and the temperature inside the carbon jig can be measured using a pyrometer.
　カーボン冶具内部の温度が目標温度の１５７０℃に到達し、温度の上昇に伴うピストンの変位がほぼ零になってから、その状態を３分間保持した。その後、加圧を止め、室温に達するまで２時間かけて降温させた。その結果、直径φ２０ｍｍ、高さ１０ｍｍの円柱状（平面形状が円形である平板形状）の単結晶蛍光体の粒子群の焼結体を得た。 The temperature inside the carbon jig reached the target temperature of 1570 ° C., and the displacement of the piston accompanying the increase in temperature became almost zero, and this state was maintained for 3 minutes. Thereafter, the pressurization was stopped, and the temperature was lowered over 2 hours until reaching room temperature. As a result, a sintered body of a single crystal phosphor particle group having a columnar shape (a flat plate shape having a circular planar shape) having a diameter of 20 mm and a height of 10 mm was obtained.
　次に、マルチワイヤーソーを用いて単結晶蛍光体の粒子群の焼結体を厚さ０．５ｍｍのウエハ状にスライスした（ステップＳ５）。 Next, the sintered body of the single crystal phosphor particle group was sliced into a wafer having a thickness of 0.5 mm using a multi-wire saw (step S5).
　次に、ウエハ状の単結晶蛍光体の粒子群の焼結体に、アニール処理を施した（ステップＳ６）。まず、アニール処理炉内にウエハ状の単結晶蛍光体の粒子群の焼結体を収容し、アニール処理炉内を真空引きした後、アルゴン雰囲気に置換した。次に、アニール処理炉内の温度をおよそ４時間で１５００℃まで昇温させ、１５００℃で１０時間保持した後、およそ４時間で室温まで降温させた。 Next, the sintered body of the particle group of the wafer-like single crystal phosphor was annealed (Step S6). First, a sintered body of a group of wafer-like single crystal phosphor particles was accommodated in an annealing furnace, and the inside of the annealing furnace was evacuated and then replaced with an argon atmosphere. Next, the temperature in the annealing furnace was raised to 1500 ° C. in about 4 hours, held at 1500 ° C. for 10 hours, and then lowered to room temperature in about 4 hours.
　次に、ウエハ状の単結晶蛍光体の粒子群の焼結体に、研削及びダイヤモンドスラリー研磨による研磨処理を施した（ステップＳ７）。この研磨処理により、ウエハ状の単結晶蛍光体の粒子群の焼結体の厚さを０．５ｍｍから０．１５ｍｍまで薄くした。 Next, the wafer-like single crystal phosphor particle group sintered body was subjected to a polishing process by grinding and diamond slurry polishing (step S7). By this polishing treatment, the thickness of the sintered body of the particle group of the wafer-like single crystal phosphor was reduced from 0.5 mm to 0.15 mm.
　以上の工程を経て、組成式（Ｙ０．９９８Ｃｅ０．００２）３Ａｌ５Ｏ１２で表される組成を有する単結晶蛍光体の粒子群の焼結体からなる、ウエハ形状の波長変換部材１を得た。 Through the above steps, a wafer-shaped wavelength conversion member comprising a sintered body of single crystal phosphor particles having a composition represented by the composition formula (Y 0.998 Ce 0.002 ) 3 Al 5 O 12. 1 was obtained.
　実施例２として、ＣＩＰ法を用いたＹＡＧ系単結晶蛍光体の粒子群の焼結体からなる波長変換部材１の製造方法の例を示す。なお、インゴットの育成工程（ステップＳ１）、粉砕工程（ステップＳ２）、スライス工程（ステップＳ５）、アニール処理工程（ステップＳ６）、研磨処理工程（ステップＳ７）については、実施例１と同じであるため、説明を省略する。 Example 2 shows an example of a method of manufacturing the wavelength conversion member 1 made of a sintered body of a YAG-based single crystal phosphor particle group using a CIP method. The ingot growing process (step S1), the crushing process (step S2), the slicing process (step S5), the annealing process (step S6), and the polishing process (step S7) are the same as in the first embodiment. Therefore, the description is omitted.
　インゴットの育成工程（ステップＳ１）、粉砕工程（ステップＳ２）を経た後、ＣＩＰ法により、単結晶蛍光体の粒子群の固形化を実施した（ステップＳ３）。まず、単結晶蛍光体の粒子群にプレプレスを施した後、ＣＩＰ装置内の内径φ２０ｍｍのゴム製冶具内に収容した。次に、ＣＩＰ装置内を加圧し、室温下で単結晶蛍光体の粒子群に３００ＭＰａの圧力を加えて、固形化した。 After passing through the ingot growing process (step S1) and the pulverizing process (step S2), the single crystal phosphor particles were solidified by the CIP method (step S3). First, the single crystal phosphor particles were pre-pressed and then housed in a rubber jig having an inner diameter of φ20 mm in a CIP apparatus. Next, the inside of the CIP device was pressurized and solidified by applying a pressure of 300 MPa to the particle group of the single crystal phosphor at room temperature.
　次に、固形化した単結晶蛍光体の粒子群を焼結した（ステップＳ５）。まず、焼成炉内に固形化した単結晶蛍光体の粒子群を収容し、焼成炉内にアルゴンガスを流しながら、常圧下で、焼成炉内の温度をおよそ８時間で１８００℃まで昇温させ、１８００℃で１０時間保持した後、およそ８時間で室温まで降温させた。その結果、直径φ１７．５ｍｍ、高さ１０ｍｍの円柱状（平面形状が円形である平板形状）の単結晶蛍光体の粒子群の焼結体を得た。 Next, the solidified single crystal phosphor particles were sintered (step S5). First, the solidified single crystal phosphor particles are accommodated in a firing furnace, and the temperature in the firing furnace is raised to 1800 ° C. in about 8 hours under normal pressure while flowing argon gas into the firing furnace. After maintaining at 1800 ° C. for 10 hours, the temperature was lowered to room temperature in about 8 hours. As a result, a sintered body of a single crystal phosphor particle group having a columnar shape (a flat plate shape having a circular planar shape) having a diameter of 17.5 mm and a height of 10 mm was obtained.
　その後、スライス工程（ステップＳ５）、アニール処理工程（ステップＳ６）、研磨処理工程（ステップＳ７）を経て、組成式（Ｙ０．９９８Ｃｅ０．００２）３Ａｌ５Ｏ１２で表される組成を有する単結晶蛍光体の粒子群の焼結体からなる、ウエハ形状の波長変換部材１を得た。 Thereafter, the composition represented by the composition formula (Y 0.998 Ce 0.002 ) 3 Al 5 O 12 is passed through a slicing process (step S5), an annealing process (step S6), and a polishing process (step S7). A wafer-shaped wavelength conversion member 1 made of a sintered body of a single crystal phosphor particle group was obtained.
　以上、本発明の実施の形態、実施例を説明したが、本発明は、上記実施の形態、実施例に限定されず、発明の主旨を逸脱しない範囲内において種々変形実施が可能である。 Although the embodiments and examples of the present invention have been described above, the present invention is not limited to the above-described embodiments and examples, and various modifications can be made without departing from the spirit of the invention.
　また、上記に記載した実施の形態、実施例は特許請求の範囲に係る発明を限定するものではない。また、実施の形態、実施例の中で説明した特徴の組合せの全てが発明の課題を解決するための手段に必須であるとは限らない点に留意すべきである。
Further, the embodiments and examples described above do not limit the invention according to the claims. In addition, it should be noted that not all combinations of features described in the embodiments and examples are essential to the means for solving the problems of the invention.
　光学系との結合効率に優れた波長変換部材、及びその波長変換部材からなる層を含む波長変換素子を提供する。 Provided is a wavelength conversion member having excellent coupling efficiency with an optical system, and a wavelength conversion element including a layer made of the wavelength conversion member.
１…波長変換部材、　１０…波長変換素子、　２０…波長変換モジュール DESCRIPTION OF SYMBOLS 1 ... Wavelength conversion member, 10 ... Wavelength conversion element, 20 ... Wavelength conversion module

Claims (7)

  1. 　蛍光体の粒子群の焼結体からなり、任意の切断面における空隙の全体に対する面積比率が０．６％以上、２５％以下の範囲内にある、
    　波長変換部材。     It consists of a sintered body of a particle group of phosphors, and the area ratio with respect to the whole voids in an arbitrary cut surface is in the range of 0.6% or more and 25% or less.
    Wavelength conversion member.
  2. 　前記蛍光体が、組成式（Ｙ１－ｘ－ｙ－ｚＬｕｘＧｄｙＣｅｚ）３＋ａＡｌ５－ａＯ１２（０≦ｘ≦０．９９９４、０≦ｙ≦０．０６６９、０．０００２≦ｚ≦０．００６７、－０．０１６≦ａ≦０．３１５）で表される組成を有する、
    　請求項１に記載の波長変換部材。     The phosphor is represented by the composition formula (Y 1-x-y- z Lu x Gd y Ce z) 3 + a Al 5-a O 12 (0 ≦ x ≦ 0.9994,0 ≦ y ≦ 0.0669,0.0002 ≦ z ≦ 0.0067, −0.016 ≦ a ≦ 0.315),
    The wavelength conversion member according to claim 1.
  3. 　前記蛍光体の粒子群が、単結晶蛍光体の粒子群である、
    　請求項１又は２に記載の波長変換部材。     The phosphor particle group is a single crystal phosphor particle group,
    The wavelength conversion member according to claim 1 or 2.
  4. 　蛍光体の粒子群の焼結体からなり、任意の切断面における空隙の全体に対する面積比率が０．６％以上、２５％以下の範囲内にある波長変換層と、
    　前記波長変換層の光取り出し側の反対側に形成された反射膜と、
    　前記反射膜の前記波長変換層の反対側に形成されたパッドメタルと、
    　を備えた、
    　波長変換素子。     A wavelength conversion layer comprising a sintered body of a group of phosphor particles, and having an area ratio of 0.6% to 25% of the entire void in an arbitrary cut surface;
    A reflective film formed on the side opposite to the light extraction side of the wavelength conversion layer;
    Pad metal formed on the opposite side of the wavelength conversion layer of the reflective film;
    With
    Wavelength conversion element.
  5. 　前記蛍光体が、組成式（Ｙ１－ｘ－ｙ－ｚＬｕｘＧｄｙＣｅｚ）３＋ａＡｌ５－ａＯ１２（０≦ｘ≦０．９９９４、０≦ｙ≦０．０６６９、０．０００２≦ｚ≦０．００６７、－０．０１６≦ａ≦０．３１５）で表される組成を有する、
    　請求項４に記載の波長変換素子。     The phosphor is represented by the composition formula (Y 1-x-y- z Lu x Gd y Ce z) 3 + a Al 5-a O 12 (0 ≦ x ≦ 0.9994,0 ≦ y ≦ 0.0669,0.0002 ≦ z ≦ 0.0067, −0.016 ≦ a ≦ 0.315),
    The wavelength conversion element according to claim 4.
  6. 　前記蛍光体の粒子群が、単結晶蛍光体の粒子群である、
    　請求項４又は５に記載の波長変換素子。     The phosphor particle group is a single crystal phosphor particle group,
    The wavelength conversion element according to claim 4 or 5.
  7. 　前記波長変換層と前記反射膜との間に形成され、前記反射膜と接する面が平坦面である平坦化膜を備えた、
    　請求項４又は５に記載の波長変換素子。     A flattening film formed between the wavelength conversion layer and the reflective film and having a flat surface in contact with the reflective film,
    The wavelength conversion element according to claim 4 or 5.
PCT/JP2019/008571 2018-03-20 2019-03-05 Wavelength conversion member and wavelength conversion element WO2019181478A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2018-053260 2018-03-20
JP2018053260A JP7178074B2 (en) 2018-03-20 2018-03-20 WAVELENGTH CONVERSION MEMBER, WAVELENGTH CONVERSION ELEMENT AND METHOD FOR MANUFACTURING WAVELENGTH CONVERSION MEMBER

Publications (1)

Publication Number Publication Date
WO2019181478A1 true WO2019181478A1 (en) 2019-09-26

Family

ID=67987794

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2019/008571 WO2019181478A1 (en) 2018-03-20 2019-03-05 Wavelength conversion member and wavelength conversion element

Country Status (2)

Country Link
JP (1) JP7178074B2 (en)
WO (1) WO2019181478A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114503378A (en) * 2019-10-03 2022-05-13 株式会社田村制作所 Wavelength conversion member

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4163540A1 (en) 2020-06-08 2023-04-12 Ngk Spark Plug Co., Ltd. Fluorescent plate, wavelength conversion member, and light source device

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009524235A (en) * 2006-01-17 2009-06-25 ルシメア カンパニー リミテッド Sheet-like antibody, method for producing the same, and light-emitting device using the same
JP2016204563A (en) * 2015-04-24 2016-12-08 太平洋セメント株式会社 Fluorescent member, manufacturing method therefor and light emitting device
WO2017068765A1 (en) * 2015-10-20 2017-04-27 パナソニックＩｐマネジメント株式会社 Wavelength conversion element and light-emitting device
WO2017094832A1 (en) * 2015-12-04 2017-06-08 東レ株式会社 Fluorescent sheet, light-emitting element using same, light source unit, display, and production method for light-emitting element
WO2017115778A1 (en) * 2015-12-28 2017-07-06 株式会社タムラ製作所 Light emitting device

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002062358A (en) * 2000-08-18 2002-02-28 Hitachi Ltd Method for polishing sintered body crystal and particle detector using polished fluorescent substance
JP5989268B2 (en) 2015-02-18 2016-09-07 日東電工株式会社 Phosphor ceramics, sealed optical semiconductor element, circuit board, optical semiconductor device, and light emitting device
JP6094617B2 (en) 2015-03-31 2017-03-15 ウシオ電機株式会社 Fluorescent light source device
CN107304984B (en) 2016-04-22 2020-06-09 松下电器产业株式会社 Wavelength conversion member and projector

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009524235A (en) * 2006-01-17 2009-06-25 ルシメア カンパニー リミテッド Sheet-like antibody, method for producing the same, and light-emitting device using the same
JP2016204563A (en) * 2015-04-24 2016-12-08 太平洋セメント株式会社 Fluorescent member, manufacturing method therefor and light emitting device
WO2017068765A1 (en) * 2015-10-20 2017-04-27 パナソニックＩｐマネジメント株式会社 Wavelength conversion element and light-emitting device
WO2017094832A1 (en) * 2015-12-04 2017-06-08 東レ株式会社 Fluorescent sheet, light-emitting element using same, light source unit, display, and production method for light-emitting element
WO2017115778A1 (en) * 2015-12-28 2017-07-06 株式会社タムラ製作所 Light emitting device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114503378A (en) * 2019-10-03 2022-05-13 株式会社田村制作所 Wavelength conversion member

Also Published As

Publication number Publication date
JP2019164302A (en) 2019-09-26
JP7178074B2 (en) 2022-11-25

Similar Documents

Publication Publication Date Title
US9722148B2 (en) Luminescent ceramic for a light emitting device
JP6480398B2 (en) Polycrystalline gallium nitride free-standing substrate and light emitting device using the same
JP2010157774A (en) Wavelength-converted semiconductor light emitting device
WO2007148829A1 (en) Composite for light conversion, light emitting device using the same, and method for controlling color tone
JP2018021193A (en) Sintered phosphor, light-emitting device, illumination device, image display device and indicator lamp for vehicle
CN108603113B (en) Phosphor and method for producing same, phosphor-containing member, and light-emitting device or projector
WO2019181478A1 (en) Wavelength conversion member and wavelength conversion element
WO2017145802A1 (en) Polycrystalline gallium nitride self-supported substrate and light emitting element using same
JP2023162184A (en) Phosphor plate, and light-emitting device using the same
JP7157898B2 (en) Wavelength conversion member
WO2019156159A1 (en) Wavelength conversion member
JP7430183B2 (en) Phosphor plate and light emitting device using it
WO2022202035A1 (en) Phosphor plate and light emitting device
CN114026201B (en) Phosphor plate and light-emitting device using same
CN115151845B (en) Phosphor plate and light-emitting device
US20230053528A1 (en) Phosphor plate and light emitting device
JP2023137938A (en) Wavelength conversion member and light source device

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19771708

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 19771708

Country of ref document: EP

Kind code of ref document: A1