JP2018010188A - Manufacturing method for wavelength conversion member, and wavelength conversion member group - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a wavelength conversion member, which allows for accurately producing a wavelength conversion member of desired chromaticity.SOLUTION: A method of manufacturing a wavelength conversion member 1 containing phosphor particles 3 is provided, comprising steps of; deriving correlation between chromaticity and thickness of a tabular base material containing phosphor particles; deriving a target thickness corresponding to target chromaticity of a wavelength conversion member 1 to be obtained based on the correlation between chromaticity and thickness; and grinding the tabular base material to the target thickness.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method of manufacturing a wavelength conversion member that converts a wavelength of light emitted from a light emitting diode (LED) or a laser diode (LD) to another wavelength, and a wavelength conversion member group.

  In recent years, attention has been focused on light-emitting devices using LEDs and LDs as next-generation light sources that replace fluorescent lamps and incandescent lamps. As an example of such a next-generation light source, a light-emitting device that combines an LED that emits blue light and a wavelength conversion member that absorbs part of the light from the LED and converts it into yellow light is disclosed. This light emitting device emits white light that is a combined light of blue light emitted from the LED and yellow light emitted from the wavelength conversion member. Patent Document 1 proposes a wavelength conversion member in which phosphor powder is dispersed in a glass matrix as an example of a wavelength conversion member.

JP 2003-258308 A

  A wavelength conversion member such as Patent Document 1 is manufactured by processing a glass base material in which phosphor powder is dispersed in a glass matrix, for example, to a predetermined thickness. However, in the wavelength conversion member obtained by such a method, color variation (chromaticity variation) of emission color between lots may occur. For this reason, it may be impossible to obtain a wavelength conversion member having a desired chromaticity with high accuracy.

  The objective of this invention is providing the manufacturing method of a wavelength conversion member and the wavelength conversion member group which make it possible to obtain the wavelength conversion member of desired chromaticity accurately.

  The method for producing a wavelength conversion member according to the present invention is a method for producing a wavelength conversion member containing phosphor particles, and a step of obtaining a correlation between chromaticity and thickness in a plate-like base material containing phosphor particles; Determining a target thickness corresponding to the target chromaticity of the obtained wavelength conversion member based on the correlation between the chromaticity and the thickness, and polishing the plate-like base material to the target thickness. It is a feature.

  In the wavelength conversion member manufacturing method according to the present invention, preferably, the plate-like base material is polished, and the chromaticity and thickness are measured by measuring the chromaticity and thickness of the polished plate-like base material. Seeking a relationship.

  In the method for manufacturing a wavelength conversion member according to the present invention, preferably, the plate-like base material is polished in a state where the chromaticity is higher than the target chromaticity, and the chromaticity and thickness of the polished plate-like base material are measured. Thus, the correlation between the chromaticity and the thickness is obtained.

  In the method for manufacturing a wavelength conversion member according to the present invention, preferably, after obtaining the correlation between the chromaticity and the thickness, the plate-like base material is further polished to the target thickness.

  In the method for manufacturing a wavelength conversion member according to the present invention, preferably, in the step of obtaining the correlation between the chromaticity and the thickness, the plate-like base material is polished by mirror polishing.

  In the wavelength conversion member manufacturing method according to the present invention, preferably, the plate-shaped base material includes a glass matrix and phosphor particles arranged in the glass matrix.

  In the wavelength conversion member manufacturing method according to the present invention, preferably, the plate-shaped base material has a first main surface and a second main surface facing each other, and the first main surface is The phosphor particles increase toward the second main surface.

  In the wavelength conversion member manufacturing method according to the present invention, preferably, the first main surface is polished after the second main surface is polished.

  In the wavelength conversion member manufacturing method according to the present invention, preferably, the first main surface and the second main surface are polished simultaneously.

  In the method for manufacturing a wavelength conversion member according to the present invention, preferably, a plurality of the plate-shaped base materials are cut out from the same base material. A plurality of the plate-shaped base materials may be cut out from the base material of the same lot.

  In the wavelength conversion member manufacturing method according to the present invention, preferably, the chromaticity variation of the manufactured plurality of wavelength conversion members is within ± 0.01.

  The wavelength conversion member group according to the present invention is a wavelength conversion member group composed of a plurality of wavelength conversion members, and the chromaticity variation of the plurality of wavelength conversion members is within ± 0.01.

  The wavelength conversion member group according to the present invention is preferably composed of 10 or more wavelength conversion members.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the wavelength conversion member which makes it possible to obtain the wavelength conversion member of desired chromaticity accurately can be provided.

It is typical sectional drawing which shows the wavelength conversion member manufactured with the manufacturing method of the wavelength conversion member which concerns on one Embodiment of this invention. It is a graph which shows an example of correlation with chromaticity and thickness in the manufacturing method of the wavelength conversion member concerning one embodiment of the present invention. It is typical sectional drawing which shows the plate-shaped base material used with the manufacturing method of the wavelength conversion member which concerns on one Embodiment of this invention. It is typical sectional drawing which shows the modification of the plate-shaped base material used with the manufacturing method of the wavelength conversion member which concerns on one Embodiment of this invention.

  Hereinafter, preferred embodiments will be described. However, the following embodiments are merely examples, and the present invention is not limited to the following embodiments. Moreover, in each drawing, the member which has the substantially the same function may be referred with the same code | symbol.

(Wavelength conversion member)
FIG. 1 is a schematic cross-sectional view showing a wavelength conversion member manufactured by a method for manufacturing a wavelength conversion member according to an embodiment of the present invention. As shown in FIG. 1, the wavelength conversion member 1 is made of phosphor glass including, for example, a glass matrix 2 and phosphor particles 3. The phosphor particles 3 are arranged in the glass matrix 2. More specifically, the phosphor particles 3 are dispersed in the glass matrix 2. The wavelength conversion member 1 has, for example, a rectangular plate shape.

The glass matrix 2 is not particularly limited as long as it can be used as a dispersion medium for the phosphor particles 3 such as inorganic phosphors. For example, borosilicate glass, phosphate glass, tin phosphate glass, bismuthate glass, tellurite glass, and the like can be used. The borosilicate-based glass, in _{mass%, SiO 2 30~85%, Al} 2 O 3 0~30%, B 2 O 3 0~50%, Li 2 O + Na 2 O + K 2 O 0~10%, and , MgO + CaO + SrO + BaO containing 0 to 50%. Examples of the tin phosphate glass include those containing, in mol%, SnO 30 to 90% and P ₂ O ₅ 1 to 70%. As the tellurite-based glass, TeO ₂ 50% or more, ZnO 0 to 45%, RO (R is at least one selected from Ca, Sr and Ba) 0 to 50%, and La ₂ O in mol%. _{3 + Gd 2 O 3 + Y} 2 O 3 which contains 0-50% thereof.

  The softening point of the glass matrix 2 is preferably 250 ° C to 1000 ° C, more preferably 300 ° C to 950 ° C, and further preferably in the range of 500 ° C to 900 ° C. If the softening point of the glass matrix 2 is too low, the mechanical strength and chemical durability of the wavelength conversion member 1 may decrease. Further, since the heat resistance of the glass matrix 2 itself is low, the glass matrix 2 itself may be softened and deformed by heat generated from the phosphor particles 3. On the other hand, if the softening point of the glass matrix 2 is too high, the phosphor particles 3 may be deteriorated and the light emission intensity of the wavelength conversion member 1 may be reduced when a firing step is included during production. In addition, from the viewpoint of further increasing the chemical stability and mechanical strength of the wavelength conversion member 1, the softening point of the glass matrix 2 is preferably 500 ° C. or higher, 600 ° C. or higher, 700 ° C. or higher, particularly 800 ° C. or higher. It is preferable that it is 850 degreeC or more. Examples of the glass constituting such a glass matrix 2 include borosilicate glass. However, when the softening point of the glass matrix 2 increases, the firing temperature also increases, and as a result, the manufacturing cost tends to increase. Therefore, from the viewpoint of manufacturing the wavelength conversion member 1 more inexpensively, the softening point of the glass matrix 2 is preferably 550 ° C. or less, 530 ° C. or less, 500 ° C. or less, 480 ° C. or less, particularly 460 ° C. or less. Is preferred. Examples of the glass constituting such a glass matrix 2 include tin phosphate glass, bismuthate glass, and tellurite glass.

  The phosphor particles 3 are not particularly limited as long as they emit fluorescence when incident excitation light is incident. Specific examples of the phosphor particles 3 include, for example, oxide phosphors, nitride phosphors, oxynitride phosphors, chloride phosphors, acid chloride phosphors, sulfide phosphors, oxysulfide phosphors, Examples thereof include one or more selected from a halide phosphor, a chalcogenide phosphor, an aluminate phosphor, a halophosphate phosphor, and a garnet compound phosphor. When blue light is used as the excitation light, for example, a phosphor that emits green light, yellow light, or red light as fluorescence can be used.

  The average particle diameter of the phosphor particles 3 is preferably 1 μm to 50 μm, and more preferably 5 μm to 25 μm. If the average particle size of the phosphor particles 3 is too small, the emission intensity may be reduced. On the other hand, if the average particle diameter of the phosphor particles 3 is too large, the emission color may be non-uniform.

  The content of the phosphor particles 3 in the wavelength conversion member 1 is preferably 1% by volume or more, 1.5% by volume or more, particularly preferably 2% by volume or more, preferably 70% by volume or less, 50% by volume. % Or less, and particularly preferably 30% by volume or less. If the content of the phosphor particles 3 is too small, it is necessary to increase the thickness of the wavelength conversion member 1 in order to obtain a desired luminescent color, and as a result, the internal scattering of the wavelength conversion member 1 increases, so that the light The extraction efficiency may be reduced. On the other hand, if the content of the phosphor particles 3 is too large, it is necessary to reduce the thickness of the wavelength conversion member 1 in order to obtain a desired emission color, so that the mechanical strength of the wavelength conversion member 1 may be reduced. .

  The thickness of the wavelength conversion member 1 is preferably 0.01 mm or more, 0.03 mm or more, 0.05 mm or more, 0.075 mm or more, particularly preferably 0.1 mm or more, preferably 1 mm or less, 0.5 mm or less. 0.35 mm or less, 0.3 mm or less, and particularly preferably 0.25 mm or less. If the wavelength conversion member 1 is too thick, light scattering and absorption in the wavelength conversion member 1 become too large, and the fluorescence emission efficiency may be lowered. If the wavelength conversion member 1 is too thin, it may be difficult to obtain sufficient light emission intensity. Moreover, the mechanical strength of the wavelength conversion member 1 may become insufficient.

  The wavelength conversion member 1 may be made of ceramics such as YAG ceramics, or may be made of phosphor particles dispersed in a resin other than those made of phosphor glass.

  Hereinafter, an example of the manufacturing method of the wavelength conversion member 1 is demonstrated.

(Manufacturing method of wavelength conversion member)
In the manufacturing method of the wavelength conversion member 1, first, a correlation between chromaticity and thickness in a plate-like base material including phosphor particles is obtained (first step). Next, based on the correlation between the obtained chromaticity and thickness, a target thickness corresponding to the target chromaticity of the obtained wavelength conversion member is determined, and the plate-like base material is polished to the target thickness, whereby the wavelength The conversion member 1 is obtained (second step).

  Hereinafter, the first step and the second step will be described in more detail.

First step;
In the first step, for example, a plate-like base material containing phosphor particles is polished, the chromaticity and thickness of the polished plate-like base material are measured, and based on the measured chromaticity and thickness of the plate-like base material Then, the correlation between the chromaticity and thickness of the plate-like base material is obtained. Specifically, by measuring the chromaticity at each thickness by changing the thickness of the plate-like base material by polishing, and plotting the chromaticity at each thickness, for example, the chromaticity as shown in the graph of FIG. Correlation with thickness can be obtained. Note that the number of plots for creating the graph may be two, but is preferably three or more from the viewpoint of obtaining the correlation between chromaticity and thickness with higher accuracy.

  The chromaticity of the plate-like base material is determined by irradiating excitation light from the light source to be used from one side main surface of the plate-like base material and using the chromaticity meter to emit light emitted from the other side main surface of the plate-like base material. It can be obtained by measuring.

  The polishing method for changing the thickness of the plate-shaped base material is not particularly limited, and can be performed by lapping or mirror polishing. Lapping has the advantage that the polishing rate is faster than mirror polishing. On the other hand, mirror polishing can improve the accuracy of the polished surface more than lapping. From the viewpoint of obtaining the correlation between chromaticity and thickness with higher accuracy, it is preferable to employ a polishing method that provides a surface state (surface roughness) equivalent to the finished surface of the final product. For example, when the final product is finished by mirror polishing, it is preferable to adopt mirror polishing as a polishing method when changing the thickness of the plate-like base material.

  Further, the correlation between the chromaticity and the thickness in the first step is such that the plate-like base material for obtaining the wavelength conversion member 1 is polished in a state where the chromaticity is higher than the target chromaticity, and the polished plate-like base material It is preferable to obtain the correlation between the thickness and the chromaticity by measuring the chromaticity and thickness. If it does in this way, the wavelength conversion member 1 which has target chromaticity can be obtained by further grind | polishing the same plate-shaped base material in the 2nd process after. But you may obtain | require the correlation of chromaticity and thickness by using the plate-shaped base material different from the plate-shaped base material for obtaining the wavelength conversion member 1. FIG. At this time, it is desirable that the plate-like base material for obtaining the correlation and the plate-like base material for obtaining the wavelength conversion member 1 are cut out from the same base material.

Second step;
In the second step, a target thickness corresponding to the target chromaticity of the obtained wavelength conversion member is determined based on the correlation between the chromaticity and the thickness obtained in the first step, and the plate-like base material is made up to the target thickness. Grind. Thereby, the wavelength conversion member 1 is obtained.

  The polishing method for polishing the plate-like base material to the target thickness is not particularly limited, and can be performed by lapping or mirror polishing. However, it is preferable to polish by lapping to a thickness slightly larger than the target thickness corresponding to the target chromaticity, and further polish to the target thickness corresponding to the target chromaticity by mirror polishing. In this case, the wavelength conversion member 1 can be obtained more easily, and the wavelength conversion member 1 can be obtained more accurately.

  As described above, in the manufacturing method of the present embodiment, the target thickness corresponding to the target chromaticity of the obtained wavelength conversion member 1 is determined based on the correlation between the chromaticity and the thickness obtained in advance, and the target thickness is determined. Polish the plate-like base material. For this reason, in the manufacturing method of the present embodiment, it is difficult for color variations (chromaticity variations) of emission colors between lots to occur. Therefore, in the manufacturing method of this embodiment, the wavelength conversion member 1 having a desired chromaticity can be obtained with high accuracy. For example, when a plurality of plate-like members are cut out from the same base material, and each of the plate-like base materials is polished to manufacture the wavelength conversion member 1, a plurality of manufactured (for example, arbitrary 10) wavelength conversion members (wavelength conversion members) The chromaticity variation of the member group is preferably within ± 0.01.

  In addition, as a plate-shaped base material, for example, as shown in FIG. 3, a plate-shaped base material 11 made of a phosphor glass including a glass matrix 12 and phosphor particles 13 arranged in the glass matrix 12. Can be used. More specifically, in the plate-like base material 11 of the present embodiment, the phosphor particles 13 are dispersed in the glass matrix 12. The glass matrix 12 and the phosphor particles 13 may be the same as the glass matrix 2 and the phosphor particles 3 described in the column of the wavelength conversion member 1 described above. The planar shape of the plate-like base material 11 is preferably rectangular, for example, like the wavelength conversion member 1.

  The plate-like base material 11 made of phosphor glass can be produced using a slurry containing glass particles that become the glass matrix 12, phosphor particles 13, and organic components such as a binder resin and a solvent. For example, the slurry can be formed by applying a slurry on a resin film such as polyethylene terephthalate by a doctor blade method or the like, and heating and drying to produce a green sheet and firing the green sheet. Alternatively, the slurry can be formed by applying the slurry onto a substrate to form a film, and drying and baking the obtained film. Further, the plate-like base material 11 made of phosphor glass can also be produced by firing a green compact of a mixed powder containing glass particles serving as the glass matrix 12 and phosphor particles 13.

In each of the above production methods, the firing temperature is preferably within the softening point of glass particles ± 150 ° C., and more preferably within the softening point of glass particles ± 100 ° C. If the firing temperature is too low, the glass particles may not soften and flow, and a dense sintered body may not be obtained. On the other hand, if the firing temperature is too high, the phosphor particles 13 are eluted in the glass and the emission intensity is lowered, or the phosphor components are diffused in the glass and the glass is colored to reduce the emission intensity. There is. Moreover, it is preferable to perform baking in a reduced pressure atmosphere. Specifically, the atmosphere during firing is preferably less than 1.013 × 10 ⁵ Pa, more preferably 1000 Pa or less, and even more preferably 400 Pa or less. Thereby, the amount of bubbles remaining in the plate-like base material 11 can be reduced. As a result, the scattering factor in the obtained wavelength conversion member can be reduced, and the luminous efficiency can be improved.

  The plate-like base material 11 may be made of a ceramic material such as YAG ceramics or a material in which phosphor particles are dispersed in a resin other than the material made of the phosphor glass.

  As shown in FIG. 3, in the plate-like base material 11 of the present embodiment, the phosphor particles 13 are uniformly dispersed in the glass matrix 12 from the first main surface 14 toward the second main surface 15. Yes. Thus, when the phosphor particles 13 are uniformly dispersed in the glass matrix 12, the wavelength conversion member 1 having a desired chromaticity can be obtained with higher accuracy.

  However, in the present invention, the phosphor particles 23 in the glass matrix 22 are directed from the first main surface 24 toward the second main surface 25 as in the plate-like base material 21 shown as a modification in FIG. You may distribute so that it may increase. Even in such a case, the correlation between the thickness and chromaticity when the first main surface 24 is polished and the correlation between the thickness and chromaticity when the second main surface 25 is polished are obtained. By setting the polishing amount with respect to the target chromaticity, the wavelength conversion member 1 can be obtained by polishing the plate-like base material 21 to the target thickness.

  In this case, it is preferable to select a surface to be polished according to the chromaticity of the plate-like base material 21. Specifically, when the chromaticity of the plate-like base material 21 is close to the target chromaticity, it is preferable to polish the first main surface 24 where the concentration of the phosphor particles 23 is low. In this way, since the chromaticity can be finely adjusted, the wavelength conversion member 1 having the target chromaticity can be obtained with higher accuracy. On the other hand, when the chromaticity of the plate-like base material 21 is away from the target chromaticity, it is preferable to polish the second main surface 25 having a high concentration of the phosphor particles 23. In this way, the amount of polishing for obtaining the wavelength conversion member 1 having the target chromaticity can be reduced, so that the production efficiency is easily improved. For example, first, polishing starts from the second main surface 25 where the concentration of the phosphor particles 23 is high, and when the chromaticity of the plate-like base material 21 approaches the target chromaticity, the concentration of the phosphor particles 23 is low. The surface 24 may be polished. Alternatively, the first main surface 24 and the second main surface 25 may be polished simultaneously. In this way, the wavelength conversion member 1 having the target chromaticity can be manufactured with higher accuracy and more efficiency.

  The thickness of the plate-shaped base materials 11 and 21 is preferably 0.01 mm or more, 0.03 mm or more, 0.05 mm or more, 0.075 mm or more, particularly preferably 0.1 mm or more, preferably 1 mm or less, It is preferably 0.5 mm or less, 0.35 mm or less, 0.3 mm or less, and particularly preferably 0.25 mm or less. When the thickness of the plate-shaped base materials 11 and 21 is in the above range, the wavelength conversion member 1 can be obtained more easily.

(Example)
YAG phosphor powder was mixed with glass powder (average particle diameter D ₅₀ : 2 μm) having each composition shown in Table 1 to obtain a mixed powder. The content of the YAG phosphor powder was 8.3% by volume in the mixed powder. The mixed powder was pressure-molded with a mold to prepare a preform of 14 mm × 14 mm × 40 mm. A preform was produced by firing the preform at the temperature shown in Table 1. Ten plate-shaped base materials of 12 mm × 12 mm × 0.3 mm were cut out from the base material.

  Measure the chromaticity at each thickness while changing the thickness by lapping and polishing each plate base material using a double-side polishing machine, and correlate the chromaticity and thickness of the plate base material from each measured value Sought a relationship. The chromaticity was determined as follows. A wavelength conversion member is installed under a light source with an excitation wavelength of 450 nm, and light emitted from the lower surface of the wavelength conversion member is taken into the integrating sphere, and then guided to a spectroscope calibrated by a standard light source, and the light energy distribution spectrum Was measured. Next, the above spectrum was integrated from CIE 1931 2-deg, x (_), y (_), z (_) color matching functions, and tristimulus values XYZ were obtained. From the tristimulus values XYZ, chromaticity x = X / (X + Y + Z) was calculated. Based on the obtained correlation, the plate-like base material was polished to a thickness corresponding to the target chromaticity. As a result, ten wavelength conversion members having a thickness of about 0.2 mm were obtained. Chromaticity was measured for each obtained wavelength conversion member, and chromaticity variation was calculated. The results are shown in Table 1.

(Comparative example)
Except that ten plate-like base materials produced in the same manner as in the example were polished to a predetermined thickness of 0.2 mm without obtaining the correlation between chromaticity and thickness, the same as in the example. Thus, a wavelength conversion member was produced. Chromaticity was measured for each obtained wavelength conversion member, and chromaticity variation was calculated. The results are shown in Table 1.

  As is clear from Table 1, the chromaticity variation of the wavelength conversion member group obtained in the example was within ± 0.004, and the absolute value was smaller than that of the comparative example.

DESCRIPTION OF SYMBOLS 1 ... Wavelength conversion member 11, 21 ... Plate-shaped base material 2, 12, 22 ... Glass matrix 3, 13, 23 ... Phosphor particle 14, 24 ... 1st main surface 15, 25 ... 2nd main surface

Claims (13)

A method for producing a wavelength conversion member containing phosphor particles,
Obtaining a correlation between chromaticity and thickness in a plate-like base material containing phosphor particles;
Based on the correlation between the chromaticity and thickness, determining a target thickness corresponding to the target chromaticity of the obtained wavelength conversion member, and polishing the plate-like base material to the target thickness;
A method for manufacturing a wavelength conversion member.   The wavelength conversion member according to claim 1, wherein the correlation between the chromaticity and the thickness is obtained by polishing the plate-like base material and measuring the chromaticity and thickness of the polished plate-like base material. Method.   Polishing the plate-like base material in a state where the chromaticity is higher than the target chromaticity, and measuring the chromaticity and thickness of the polished plate-like base material, thereby obtaining a correlation between the chromaticity and the thickness. The manufacturing method of the wavelength conversion member of Claim 2.   The method for manufacturing a wavelength conversion member according to claim 3, wherein after obtaining the correlation between the chromaticity and the thickness, the plate-like base material is further polished to the target thickness.   The method for manufacturing a wavelength conversion member according to any one of claims 1 to 4, wherein in the step of obtaining a correlation between the chromaticity and the thickness, the plate-like base material is polished by mirror polishing.   The manufacturing method of the wavelength conversion member of any one of Claims 1-5 in which the said plate-shaped base material contains the glass matrix and the fluorescent substance particle distribute | arranged in the said glass matrix.   The plate-like base material has a first main surface and a second main surface facing each other, and the phosphor particles increase from the first main surface toward the second main surface. The method for producing a wavelength conversion member according to claim 6.   The method for manufacturing a wavelength conversion member according to claim 7, wherein after polishing the second main surface, the first main surface is polished.   The method for manufacturing a wavelength conversion member according to claim 7, wherein the first main surface and the second main surface are polished simultaneously.   The manufacturing method of the wavelength conversion member of any one of Claims 1-9 which cuts out the said several plate-shaped base material from the same base material.   The manufacturing method of the wavelength conversion member of any one of Claims 1-10 whose chromaticity dispersion | variation of the manufactured several wavelength conversion member is less than +/- 0.01.   A wavelength conversion member group comprising a plurality of wavelength conversion members, wherein the chromaticity variation of the plurality of wavelength conversion members is within ± 0.01.   The wavelength conversion member group of Claim 12 comprised from a 10 or more wavelength conversion member.

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