JP2012031328A - Method for producing wavelength conversion member, wavelength conversion member and light source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a wavelength conversion member, which can easily produce a high strength wavelength conversion member.SOLUTION: Preferably a sintered preform 30 is formed by: forming a compact containing an inorganic phosphor and glass powder but not containing a binder; and sintering the compact under reduced-pressure atmosphere. In this case, voids in the sintered preform 30 can be reduced, thereby producing the higher strength wavelength conversion member. The shape of the wavelength conversion member is not particularly limited. Also the wavelength conversion member may be in the form of a plate or rod. Specifically, the wavelength conversion member can be a plate form whose dimensional ratio of length to thickness is 100:1 or larger, for example.

Description

  The present invention relates to a method for manufacturing a wavelength conversion member, a wavelength conversion member manufactured by the method, and a light source including the same. In particular, the present invention relates to a method for manufacturing a wavelength conversion member in which an inorganic phosphor powder is dispersed in a glass base material, a wavelength conversion member manufactured by the method, and a light source including the same.

  In recent years, for example, a white light source used for applications such as a backlight of a liquid crystal display has been actively developed. As an example of such a white light source, for example, in Patent Document 1 below, a part of light from an LED is absorbed on the light emitting side of an LED (Light Emitting Diode) that emits blue light, and yellow light is emitted. A light source in which a wavelength conversion member is arranged is disclosed. This light source can emit white light by combining blue light and yellow light.

  As this wavelength conversion member, a material in which an inorganic phosphor powder is dispersed in a resin matrix has been conventionally used. However, in the wavelength conversion member in which the inorganic phosphor powder is dispersed in the resin matrix, there is a problem that the resin deteriorates due to the light from the LED, and the luminance of the white light source tends to decrease with time. In particular, when the light from the LED is a light having a short wavelength such as blue light and a strong energy, the resin is likely to deteriorate.

  In view of such a problem, for example, Patent Documents 2 and 3 below propose a wavelength conversion member in which inorganic phosphor powder is dispersed in glass. The wavelength conversion members described in Patent Documents 2 and 3 do not contain a resin and are composed only of an inorganic solid, and thus have excellent heat resistance and weather resistance. Therefore, by using this wavelength conversion member, it is possible to realize a white light source whose luminance is not easily lowered.

JP 2007-25285 A JP 2005-11933 A Japanese Patent No. 4158012 JP 2007-182529 A

  However, a wavelength conversion member using glass as a dispersion medium has a problem that it is difficult to mold compared to a wavelength conversion member using resin as a dispersion medium. In particular, it is difficult to form a wavelength conversion member using glass as a dispersion medium into a plate shape.

  For example, Patent Document 4 proposes a method of manufacturing a plate-shaped wavelength conversion member by producing a green sheet from a paste containing glass powder and inorganic phosphor powder, and firing the green sheet. .

  However, the method for manufacturing a wavelength conversion member described in Patent Document 4 has a problem that it is difficult to easily manufacture a high-intensity wavelength conversion member.

  This invention is made | formed in view of the point which concerns, The objective is to provide the manufacturing method of the wavelength conversion member which can manufacture a high intensity | strength wavelength conversion member easily.

  As a result of diligent research, the present inventors have found that the strength of the sintered body can be increased by heating and stretching the sintered body preform of the inorganic phosphor powder and the glass powder. It came to be accomplished.

  That is, in the method for producing a wavelength conversion member according to the present invention, the wavelength conversion member is formed by heating and stretching a sintered body preform of an inorganic phosphor powder and a glass powder. For this reason, a high intensity | strength wavelength conversion member can be manufactured easily.

  In the present invention, it is preferable to perform the heat stretching of the sintered body preform at a temperature not lower than the softening point of the glass powder and not higher than 200 ° C. higher than the softening point of the glass powder. In this case, heating and stretching of the sintered body preform can be suitably performed. In addition, a wavelength conversion member with higher strength can be manufactured. In addition, when there is much content of the inorganic fluorescent substance in a sintered compact preform, for example, when it is 5 mass% or more, especially 8 mass% or more, it is 100 degreeC or more from the softening point of glass powder, especially 150 degreeC. It is preferable to perform heat stretching at a higher temperature.

  In the present invention, it is preferable to form a sintered body preform by forming a molded body containing an inorganic phosphor and glass powder and not containing a binder, and firing the molded body in a reduced-pressure atmosphere. In this case, voids in the sintered body preform can be reduced. Accordingly, it is possible to manufacture a wavelength conversion member with higher strength.

  The wavelength conversion member according to the present invention is obtained by heat-stretching a sintered body preform of an inorganic phosphor powder and a glass powder. As described above, the strength of the sintered body can be increased by subjecting the sintered body preform to heat-stretching. Therefore, the wavelength conversion member according to the present invention has high strength.

  The shape of the wavelength conversion member according to the present invention is not particularly limited. The wavelength conversion member according to the present invention may be, for example, a plate shape or a rod shape. Specifically, for example, the wavelength conversion member according to the present invention may have a plate shape in which the ratio of the length dimension to the thickness dimension is 100: 1 or more.

  In the present invention, “plate shape” includes “sheet shape” and “film shape”.

In the wavelength conversion member of the present invention, on the surface of the wavelength conversion member, the average number of linear grooves having a length of 30 μm or more and a depth of 0.05 μm or more per 0.25 mm ² is preferably 100 or less, It is more preferably 50 or less, further preferably 20 or less, still more preferably 10 or less, and particularly preferably substantially absent. In this case, cracks due to the linear grooves are less likely to occur on the surface of the wavelength conversion member due to external pressure, and the problem of cracking and strength reduction is less likely to occur. In addition, light scattering loss due to the linear grooves is reduced. For this reason, the loss on the surface of the wavelength conversion member is reduced, and the light extraction efficiency is increased. As a result, it is possible to obtain a wavelength conversion member having a high light emission intensity and having very small variations in color reproducibility and light emission intensity.

  The length of the linear groove can be measured, for example, by observing an image on the surface of the wavelength conversion member using a scanning electron microscope (SEM). Further, the depth of the linear groove can be measured using, for example, a stylus type surface roughness meter. Here, the depth of the linear groove refers to the distance from the average line to the tip of the linear groove in the measurement curve of the member surface shape.

  In the present invention, the inorganic phosphor powder can be appropriately selected according to required excitation light, converted light, and the like. Examples of inorganic phosphor powders include oxide inorganic phosphors, nitride inorganic phosphors, oxynitride inorganic phosphors, sulfide inorganic phosphors, oxysulfide inorganic phosphors, rare earth sulfide inorganic phosphors, and aluminate chlorides. 1 type or more selected from inorganic phosphors and halophosphate inorganic phosphors.

  The light source which concerns on this invention is equipped with the wavelength conversion member which concerns on the said invention, and the light emitting element which radiate | emits the excitation light of a wavelength conversion member with respect to a wavelength conversion member. As described above, the wavelength conversion member according to the present invention has high strength. Therefore, the light source according to the present invention has high mechanical durability.

  In the present invention, the light emitting element is not particularly limited, and can be constituted by, for example, an LED. By using the LED, a long product life and low power consumption can be realized.

  The light source according to the present invention may emit light of any color tone. The light source according to the present invention includes, for example, a light emitting element that emits blue light and a wavelength conversion member that absorbs blue light from the LED and emits yellow light, and emits white light by combining blue light and yellow light. It may be emitted.

  The light source according to the present invention may include a plurality of light emitting elements.

  In the present invention, “blue light” refers to light in the wavelength range of 440 nm to 480 nm. “White light” refers to light having a chromaticity x of 0.25 to 0.45 and a chromaticity y of 0.25 to 0.45. In particular, light close to the locus of black body radiation is preferable.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the wavelength conversion member which can manufacture a high intensity | strength wavelength conversion member easily is provided.

It is a typical side view of the light source which concerns on one Embodiment of this invention. It is a typical perspective view of a sintered compact preform. It is a typical side view for demonstrating a heating extending process.

  Hereinafter, a preferred embodiment in which the present invention is implemented will be described using the light source 1 shown in FIG. 1 as an example. However, the light source 1 is merely an example. The light source and the wavelength conversion member according to the present invention are not limited to the light source 1 and the wavelength conversion member 10 included in the light source 1.

  FIG. 1 is a schematic side view of a light source according to the present embodiment. As shown in FIG. 1, the light source 1 includes a wavelength conversion member 10 and a plurality of light emitting elements 20. In the light source 1, a part of the excitation light 20 a emitted from the light emitting element 20 is absorbed by the wavelength conversion member 10, and the fluorescence 10 a is emitted from the wavelength conversion member 10 accordingly. On the other hand, a part of the excitation light 20a is transmitted as it is without being absorbed by the wavelength conversion member 10, and a combined light 2 (for example, white light) of the transmitted excitation light 20a and fluorescence 10a is emitted.

  The light emitting element 20 is not particularly limited, and can be constituted by, for example, an LED, a plasma light emitting element, an electroluminescence light emitting element, or the like.

  In the present embodiment, the wavelength conversion member 10 is formed by dispersing inorganic phosphor powder in glass.

  The inorganic phosphor powder can be appropriately selected according to the wavelength of the synthesized light 2 to be emitted from the light source 1, the wavelength of the excitation light 20a emitted from the light emitting element 20, or the like. Examples of inorganic phosphor powders include oxide inorganic phosphors, nitride inorganic phosphors, oxynitride inorganic phosphors, sulfide inorganic phosphors, oxysulfide inorganic phosphors, rare earth sulfide inorganic phosphors, and aluminate chlorides. Inorganic phosphors and halophosphate inorganic phosphors can be used.

Examples of inorganic phosphor powder that emits blue light when irradiated with ultraviolet to near-ultraviolet excitation light having a wavelength of 300 to 440 nm include Sr ₅ (PO ₄ ) ₃ Cl: Eu ²⁺ , (Sr, Ba) MgAl ₁₀ O ₁₇ : Eu ²⁺ , (Sr, Ba) ₃ MgSi ₂ O ₈ : Eu ^{2+ and the} like.

Inorganic phosphor powders that emit green fluorescence (fluorescence having a wavelength of 500 nm to 540 nm) when irradiated with excitation light having a wavelength of 300 to 440 nm, such as SrAl ₂ O ₄ : Eu ²⁺ and SrGa ₂ S ₄ : Eu. ²⁺ , SrBaSiO ₄ : Eu ²⁺ , CdS: In, CaS: Ce ³⁺ , Y ₃ (Al, Gd) ₅ O ₁₂ : Ce ²⁺ , Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce ³⁺ , SrSiOn: Eu ²⁺ , ZnS: Al ³⁺ , Cu ⁺ , CaS: Sn ²⁺ , CaS: Sn ²⁺ , F, CaSO ₄ : Ce ³⁺ , Mn ²⁺ , LiAlO ₂ : Mn ²⁺ , BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , Mn ²⁺ , ZnS: Cu ⁺ , Cl ^{_{-, Ca 3 WO 6: U}} , Ca 3 SiO 4 Cl 2: Eu 2+, Sr 0.2 Ba 0.7 Cl _1.1 Al ₂ O _3.45 : Ce ³⁺ , Mn ²⁺ , Ba ₂ MgSi ₂ O ₇ : Eu ²⁺ , Ba ₂ SiO ₄ : Eu ²⁺ , Ba ₂ Li ₂ Si ₂ O ₇ : Eu ²⁺ , ZnO: S, _{ZnO: Zn, Ca 2 Ba 3} (PO 4) 3 Cl: Eu 2+, BaAl 2 O 4: ^{Eu 2+.}

Inorganic phosphor powders that emit green fluorescence (fluorescence having a wavelength of 500 nm to 540 nm) when irradiated with blue excitation light having a wavelength of 440 to 480 nm include SrAl ₂ O ₄ : Eu ²⁺ , SrGa ₂ S ₄ : Eu ²⁺ , SrBaSiO ₄ : Eu ²⁺ , CdS: In, CaS: Ce ³⁺ , Y ₃ (Al, Gd) ₅ O ₁₂ : Ce ²⁺ , Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce ³⁺ , SrSiOn: Eu ^{2+ and the} like.

As the non-fluorescent powder that emits yellow fluorescence (fluorescence having a wavelength of 540 nm to 595 nm) when irradiated with excitation light having a wavelength of 300 to 440 nm, ZnS: Eu ²⁺ , Ba ₅ (PO ₄ ) ₃ Cl: U, Sr ₃ WO ₆ : U, CaGa ₂ S ₄ : Eu ²⁺ , SrSO ₄ : Eu ²⁺ , Mn ²⁺ , ZnS: P, ZnS: P ³⁻ , Cl ⁻ , ZnS: Mn ^{2+ and the} like.

As an inorganic phosphor powder that emits yellow fluorescence (fluorescence having a wavelength of 540 nm to 595 nm) when irradiated with blue excitation light having a wavelength of 440 to 480 nm, Y ₃ (Al, Gd) ₅ O ₁₂ : Ce ²⁺ , Ba ₅ ( PO ₄ ) ₃ Cl: U, CaGa ₂ S ₄ : Eu ²⁺ , Sr ₂ SiO ₄ : Eu ²⁺ .

Examples of the inorganic phosphor powder that emits red fluorescence (fluorescence having a wavelength of 600 nm to 700 nm) when irradiated with excitation light having a wavelength of 300 to 440 nm are CaS: Yb ²⁺ , Cl, Gd ₃ Ga ₄ O ₁₂ : Cr ³⁺ , CaGa ₂ S ₄ : Mn ²⁺ , Na (Mg, Mn) ₂ LiSi ₄ O ₁₀ F ₂ : Mn, ZnS: Sn ²⁺ , Y ₃ Al ₅ O ₁₂ : Cr ³⁺ , SrB ₈ O ₁₃ : Sm ²⁺ , MgSr ₃ Si ₂ O ₈ : Eu ²⁺ , Mn ²⁺ , α-SrO.3B ₂ O ₃ : Sm ²⁺ , ZnS-CdS, ZnSe: Cu ⁺ , Cl, ZnGa ₂ S ₄ : Mn ²⁺ , ZnO: Bi ³⁺ , BaS ^{: Au, K, ZnS: Pb} 2+, ZnS: Sn 2+, Li +, ZnS: Pb, Cu, CaTiO 3: Pr 3+, CaTiO 3 _{^{Eu 3+, Y 2 O 3:}} Eu 3+, (Y, Gd) 2 O 3: Eu 3+, CaS: Pb 2+, Mn 2+, YPO 4: Eu 3+, Ca 2 MgSi 2 O 7: Eu 2+, Mn 2+, Y (P, V) O ₄ : Eu ³⁺ , Y ₂ O ₂ S: Eu ³⁺ , SrAl ₄ O ₇ : Eu ³⁺ , CaYAlO ₄ : Eu ³⁺ , LaO ₂ S: Eu ³⁺ , LiW ₂ O ₈ : Eu ³⁺ , Sm ³⁺ , (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ , Mn ²⁺ , Ba ₃ MgSi ₂ O ₈ : Eu ²⁺ , Mn ^{2+ and the} like.

Examples of inorganic phosphor powder that emits red fluorescence (fluorescence having a wavelength of 600 nm to 700 nm) when irradiated with blue excitation light having a wavelength of 440 to 480 nm include ZnS: Mn ²⁺ , Te ²⁺ , Mg ₂ TiO ₄ : Mn ⁴⁺ , K ₂ SiF ₆ : Mn ⁴⁺ , SrS: Eu ²⁺ , CaS: Eu ²⁺ , Na _1.23 K _0.42 Eu _0.12 TiSi ₄ O ₁₁ , Na _1.23 K _0.42 Eu _0.12 TiSi ₅ O ₁₃ : Eu ³⁺ , CdS: In, Te, CaAlSiN ₃ : Eu ²⁺ , CaSiN ₃ : Eu ²⁺ , (Ca, Sr) ₂ Si ₅ N ₈ : Eu ²⁺ , Eu ₂ W ₂ O _{7 and the} like.

  A plurality of inorganic phosphor powders may be mixed and used in accordance with the wavelength range of excitation light or light emission. For example, when white light is obtained by irradiation with ultraviolet excitation light, inorganic phosphor powders emitting blue, green, and red fluorescence may be mixed and used.

  For example, a white light source 1 useful as a light source of a liquid crystal display is realized by using an LED that emits blue light as the light emitting element 20 and using a wavelength conversion member 10 that absorbs blue light and emits yellow light. Can do.

The glass as the dispersion medium is not particularly limited as long as it can stably hold the inorganic phosphor powder. Specific examples of the glass that can be used as the dispersion medium include, for example, silicate glass, borate glass, SiO ₂ —B ₂ O ₃ —RO glass (R is at least Mg, Ca, Sr, and Ba). Borosilicate glass such as SnO—P ₂ O ₅ glass, borophosphate glass, and the like. Of _these, SiO ₂ -B ₂ O 3 -RO based glass or _SnO-P 2 _{O 5} based glass is preferably used.

SiO ₂ -B ₂ O ₃ -RO based glass, for example, in _{mol%, SiO 2 30~80%, B} 2 O 3 1~30%, 0~10% MgO, CaO 0~30%, SrO 0~ The glass may contain 20%, BaO 0-40%, MgO + CaO + SrO + BaO 5-45%, Al ₂ O ₃ 0-10% and ZnO 0-10%.

In addition to the above components, SiO ₂ —B ₂ O ₃ —RO-based glass reduces the softening point of glass such as alkali metal oxides such as Li ₂ O, Na ₂ O, K ₂ O, etc. Components that enable firing, components that improve the meltability of glass such as P ₂ O _5, and chemicals of glasses such as Ta ₂ O ₅ , TiO ₂ , Nb ₂ O ₅ , Gd ₂ O ₃ , and La ₂ O ₃ It may further contain a component for improving durability.

_SnO-P 2 _{O 5} based glass, for example, in _{mol%, SnO 35~80%, P 2} O 5 5~40%, B 2 O 3 0~30%, Al 2 O 3 0~10%, SiO _{2 0~10%, Li 2 O 0~10} %, Na 2 O 0~10%, K 2 O 0~10%, 0~10% MgO, CaO 0~10%, SrO 0~10% and BaO 0 It may be a glass containing 10% to 10% composition.

In addition to the above components, SnO—P ₂ O ₅ glass is composed of components that improve weather resistance such as Ta ₂ O ₅ , TiO ₂ , Nb ₂ O ₅ , Gd ₂ O ₃ , La ₂ O ₃ , ZnO It may further contain a component that stabilizes the glass.

From the viewpoint of lowering the softening point of SnO—P ₂ O ₅ glass and stabilizing the glass, the molar ratio of SnO to P ₂ O ₅ (SnO / P ₂ O ₅ ) is in the range of 0.9 to 16. It is preferable that it is in the range, more preferably in the range of 1.5 to 10, and still more preferably in the range of 2 to 5. When the molar ratio (SnO / P ₂ O ₅ ) is too small, firing at a low temperature becomes difficult, and the inorganic phosphor powder may be easily deteriorated during firing. On the other hand, if the molar ratio (SnO / P ₂ O ₅ ) is too small, the weather resistance may be too low. On the other hand, if the molar ratio (SnO / P ₂ O ₅ ) is too large, the glass tends to be devitrified, and the transmittance of the glass may be too low.

  Although content of the inorganic fluorescent substance powder in the wavelength conversion member 10 is not specifically limited, For example, it is preferable that it is 0.01 mass%-30 mass%, and it is more preferable that it is 0.1 mass%-25 mass%. The content is preferably 1% by mass to 20% by mass.

  The shape of the wavelength conversion member 10 is not particularly limited. The wavelength conversion member 10 may be, for example, a plate shape or a rod shape. In the present embodiment, an example in which the wavelength conversion member 10 has a plate shape in which the ratio of the length dimension to the thickness dimension is 100: 1 or more will be described.

  Next, the manufacturing method of the wavelength conversion member 10 of this embodiment is demonstrated, mainly referring FIG.2 and FIG.3.

  First, a so-called binder-free molded body containing inorganic phosphor powder and glass powder and not containing a binder is prepared. Specifically, the molded body can be produced, for example, by press-molding a mixed powder of inorganic phosphor powder and glass powder using a mold.

  In addition, it is preferable that the average particle diameter D50 of inorganic fluorescent substance powder is 1 micrometer-50 micrometers, and it is more preferable that they are 5 micrometers-25 micrometers. If the average particle diameter D50 of the inorganic phosphor powder is too small, the emission intensity tends to decrease. On the other hand, if the average particle diameter D50 of the inorganic phosphor powder is too large, the uniformity of the luminescent color tends to decrease.

  The average particle diameter D50 of the glass powder is preferably 0.1 μm to 100 μm, and more preferably 1 μm to 50 μm. If the average particle diameter D50 of the glass powder is too small, bubbles are likely to be generated during firing. For this reason, the intensity | strength of the wavelength conversion member 10 obtained may fall. In addition, light scattering in the wavelength conversion member 10 is lowered, and the light emission efficiency may be reduced. On the other hand, when the average particle diameter D50 of the glass powder is too large, the inorganic phosphor powder is difficult to be uniformly dispersed, and as a result, the light emission efficiency of the obtained wavelength conversion member 10 may be lowered.

  In the present specification, the average particle diameter D50 is a value measured according to JIS-R1629 using SALD200J manufactured by Shimadzu Corporation.

  Next, the formed compact is fired in a reduced-pressure atmosphere to form a sintered compact preform 30 shown in FIG. The pressure of the atmosphere in the firing step is preferably less than 1 atm, for example, because bubbles hardly remain in the sintered body preform. The maximum firing temperature can be, for example, about the softening point of the glass powder to the softening point + 100 ° C.

  In addition, in this embodiment, since the wavelength conversion member 10 is plate shape, it is preferable that the sintered compact preform 30 is also plate shape, a rectangular parallelepiped shape, or a cube shape.

  Next, the wavelength conversion member 10 is formed by heating and stretching the obtained sintered body preform 30. Specifically, as shown in FIG. 3, the end of the sintered body preform 30 is pulled by a roller 32 in a state where the sintered body preform 30 is heated and softened by the heater 31. Thereby, the softened sintered body preform 30 is stretched, and the wavelength conversion member 10 is formed.

  The heating and stretching of the sintered body preform 30 is preferably performed at a temperature not lower than the softening point of the glass powder and not higher than 200 ° C. higher than the softening point of the glass powder.

  Although ratio (t1 / t0) of thickness t1 after extending | stretching with respect to thickness t0 of the sintered compact preform 30 before extending | stretching is not specifically limited, For example, it can be set as about 5-50.

  As described above, in this embodiment, the wavelength conversion member 10 is formed by heating and stretching the sintered body preform 30. For this reason, the high intensity | strength wavelength conversion member 10 can be manufactured easily. In addition, it is considered that the reason why the high-intensity wavelength conversion member 10 is easily obtained by heat stretching is due to the following reasons 1 to 3.

  Reason 1: A compressive stress layer (for example, a layer having a compressive stress of about 0.1 MPa to 10 MPa) is formed on the surface layer of the wavelength conversion member 10 by heat stretching.

  Reason 2: The reaction between the surface layer of the inorganic phosphor powder and the glass proceeds, and the adhesion strength between the inorganic phosphor powder and the glass increases.

Reason 3: The surface layer of the sintered body preform 30 is softened, so that the surface layer is repaired. Accordingly, in the manufactured wavelength conversion member 10, the average number of linear grooves having a length of 30 μm or more and a depth of 0.05 μm or more per 0.25 mm ² is 100 or less on the surface of the wavelength conversion member 10. It is preferably 50 or less, more preferably 20 or less, still more preferably 10 or less, and particularly preferably substantially absent.

  Moreover, in this embodiment, the heat-stretching of the sintered compact preform 30 is performed at a temperature not lower than the softening point of the glass powder and not higher than 200 ° C. higher than the softening point of the glass powder. For this reason, the wavelength conversion member 10 of higher intensity | strength can be manufactured. When the heating and stretching temperature of the sintered body preform 30 is too low, the heating and stretching cannot be suitably performed, and the strength of the obtained wavelength conversion member 10 may be lowered. On the other hand, if the heating and stretching temperature of the sintered body preform 30 is too high, the wavelength conversion member 10 having a desired shape may not be obtained.

  In this embodiment, the binder-free molded body is fired in a reduced-pressure atmosphere. For this reason, the porosity of the sintered compact preform 30 and by extension, the wavelength conversion member 10 can be made low. Therefore, it is possible to manufacture the wavelength conversion member 10 having higher strength and higher luminous efficiency. The porosity of the sintered body preform 30 and the wavelength conversion member 10 is preferably 2% by volume or less, and more preferably 1% by volume or less.

  In the present embodiment, the example in which the plate-like wavelength conversion member 10 is manufactured by heating and stretching the plate-like sintered body preform 30 has been described. However, each shape of the sintered compact preform 30 and the wavelength conversion member 10 is not limited to a plate shape. For example, you may manufacture a rod-shaped wavelength conversion member by heat-drawing a rod-shaped sintered compact preform.

  Hereinafter, the present invention will be described in more detail on the basis of specific examples. However, the present invention is not limited to the following examples, and may be appropriately modified and implemented without departing from the scope of the present invention. Is possible.

(Example)
The following glass powder and inorganic phosphor powder are mixed so that the mass ratio (glass powder: inorganic phosphor powder) is 9: 1, and press molded using a mold to obtain a molded body. Produced. Thereafter, the compact was fired under the following conditions to produce a sintered body preform.

Composition (mass ratio) of glass powder: SiO ₂ 50%, BaO 25%, CaO 10%, B ₂ O ₃ 5%, Al ₂ O ₃ 5%, ZnO 5%
Average particle diameter of glass powder (D50): 3 μm
Softening point of glass powder: 850 ° C
Composition of inorganic phosphor powder: Y ₃ (Al, Gd) ₅ O ₁₂ : Ce ²⁺
Average particle size (D50) of inorganic phosphor powder: 20 μm
Maximum firing temperature: 850 ° C
Firing atmosphere: Air Firing atmosphere pressure: 100 Pa

  Next, the obtained sintered body was cut into a rectangular parallelepiped shape having a width of 15 mm, a thickness of 4.5 mm, and a length of 100 mm to produce a base material. Next, this base material is set in a stretch molding machine, carried into a molding furnace held at 1020 ° C. (softening point + 170 ° C.) at a feed rate of 1 mm / min, and pulled out from the molding furnace outlet at a rate of 225 mm / min. It was. The drawn molded body was cut with an automatic cutting machine to prepare a rectangular long wavelength conversion member having a width of 1 mm, a thickness of 0.3 mm, and a length of 300 mm. When this wavelength conversion member was irradiated with light from a blue LED (emission wavelength: 460 nm), white light emission was confirmed.

  The three-point bending strength of the wavelength conversion member obtained in this example was 250 MPa when measured according to JIS-R1601 using an autograph AG-10kNIS manufactured by Shimadzu Corporation.

(Comparative example)
A glass paste containing the glass powder used in the above examples and the inorganic phosphor powder at a mass ratio of 9: 1 was prepared. The glass paste was applied on a PET film to produce a green sheet. After that, the green sheet was fired under the same firing conditions as in the above example to produce a wavelength conversion member having the same dimensions as in the above example.

  The three-point bending strength of the obtained wavelength conversion member was measured by the same method as in the above example, and found to be 130 MPa.

  From the above results, it can be seen that a high-intensity wavelength conversion member can be produced by heating and stretching the sintered body preform.

DESCRIPTION OF SYMBOLS 1 ... Light source 2 ... Synthetic light 10 ... Wavelength conversion member 10a ... Fluorescence 20 ... Light emitting element 20a ... Excitation light 30 ... Sintered body preform 31 ... Heater 32 ... Roller

Claims (12)

  The manufacturing method of the wavelength conversion member which shape | molds a wavelength conversion member by heat-stretching the sintered compact preform of inorganic fluorescent substance powder and glass powder.   The wavelength conversion member according to claim 1, wherein the heating and stretching of the sintered body preform is performed at a temperature not lower than the softening point of the glass powder and not higher than 200 ° C higher than the softening point of the glass powder. Production method.   The sintered body preform is formed by forming a molded body that includes the inorganic phosphor and the glass powder, does not include a binder, and is fired in a reduced-pressure atmosphere. A manufacturing method of the wavelength conversion member given in 2.   A wavelength conversion member formed by heat-stretching a sintered body preform of inorganic phosphor powder and glass powder.   The wavelength conversion member according to claim 4 which is plate shape or rod shape.   The wavelength conversion member according to claim 5, wherein the ratio between the length dimension and the thickness dimension is a plate shape having a ratio of 100: 1 or more.   The inorganic phosphor powder includes oxide inorganic phosphor, nitride inorganic phosphor, oxynitride inorganic phosphor, sulfide inorganic phosphor, oxysulfide inorganic phosphor, rare earth sulfide inorganic phosphor, and aluminate chloride. The wavelength conversion member according to any one of claims 4 to 6, comprising at least one selected from an inorganic phosphor and a halophosphate chloride inorganic phosphor. 8. The average number of existing linear grooves per 0.25 mm ² having a length of 30 μm or more and a depth of 0.05 μm or more on the surface of the wavelength conversion member is 100 or less. The wavelength conversion member as described in 2. The wavelength conversion member according to any one of claims 4 to 8,
A light emitting element that emits excitation light of the wavelength conversion member with respect to the wavelength conversion member,
A light source comprising   The light source according to claim 9, wherein the light emitting element is an LED. The light emitting element emits blue light,
The light source according to claim 9 or 10, wherein the wavelength conversion member absorbs part of the blue light to emit yellow light, and emits white light by combining the blue light and the yellow light.   The light source according to any one of claims 9 to 11, comprising a plurality of the light emitting elements.

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