JP2016018878A - Wavelength-conversion laminated composite, and method for manufacturing wavelength-conversion laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-rigidity wavelength-conversion laminated composite which enables the suppression of diffusion of an activator from a first layer into a second layer with the aid of an intermediate layer, and enables the emission of light of desired coloration with a high light emission efficiency.SOLUTION: A wavelength-conversion laminated composite comprises: a first layer 2 including a YAG fluorescent material including an activator and AlO; an intermediate layer 4 of AlOin which of all of particles thereof, particles of 20-80 μm in diameter account for 90% or more; a second layer 3 including a YAG material which is equal to or less than 10% of the activator content in the first layer and AlO. In the first layer, the volume composition ratio of the activator-doped YAG fluorescent material to AlOis in a range of 10:90 to 60:40. In the second layer, the volume composition ratio of the YAG material to AlOis in a range of 10:90 to 40:60. The wavelength-conversion laminated composite has a connection structure in which AlOparticles are connected to each other in each of the first and second layers and at each interface of the layers.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wavelength conversion laminate composite and a method of manufacturing a wavelength conversion laminate, and converts light of a predetermined wavelength from, for example, an LED (light emitting diode) or LD (laser diode) into light having a wavelength different from the wavelength of the light. The present invention relates to a wavelength conversion laminate composite and a method for producing the wavelength conversion laminate.

  Conventionally, for example, YAG (yttrium, aluminum, garnet) -based phosphors containing Ce (cerium) are known as phosphors that emit blue light upon receiving blue light. When such YAG phosphor is irradiated with blue light, white light can be obtained by mixing the emitted blue light and the fluorescent color emitted from the YAG phosphor.

  Patent Document 1 proposes a semiconductor chip including the phosphor. The semiconductor chip disclosed in Patent Document 1 is mounted and used on, for example, an optoelectronic device. Specifically, as shown in FIG. 3, the optoelectronic device 50 has a semiconductor chip 52 disposed on a device casing 51 serving as a heat sink, and releases heat from the semiconductor chip 52 from the device casing 51. It has become.

As shown in FIG. 3, the semiconductor chip 52 includes a ceramic conversion element 55 disposed on a beam emission surface 54 of a semiconductor body 56. The ceramic conversion element 55 includes an active layer 58 made of, for example, a YAG: Ce garnet phosphor, and a carrier layer 57 disposed thereabove. In addition, the arrow in FIG. 3 has shown the discharge | emission direction of heat.
Further, the active layer 58 and the carrier layer 57 will be described. The active layer 58 is made of a phosphor material (for example, YAG: Ce) doped with an activator (for example, Ce), and emits light in a predetermined wavelength region. It has a function of converting to light in other wavelength regions. The carrier layer 57 is made of a phosphor material (for example, YAG) that does not contain an activator.

  Further, in Patent Document 1, as the ceramic conversion element 55, as shown in FIG. 4, in order to suppress the diffusion of the activator (Ce) from the active layer 58 into the carrier layer 57, What is provided with the suppression layer 59 arrange | positioned between the support tanks 57 is proposed. The suppression layer 59 is made of, for example, aluminum oxide.

In the case of manufacturing the above-described ceramic conversion element 55, green sheets to be the active layer 58 and the carrier layer 57 are formed with ceramic powder, a binder, and an additive, and after laminating these, sintering is performed. The ceramic conversion elements connected to each other can be manufactured.
Similarly, in the case of manufacturing the ceramic conversion element 55 including the suppression layer 59, a green sheet that forms each of the active layer 58, the carrier layer 57, and the suppression layer 59 is formed with ceramic powder, a binder, and an additive. After laminating them, the ceramic conversion elements connected to each other can be manufactured by sintering.

Special table 2014-504807 gazette

Various evaluations and researches have been made on ceramic conversion elements obtained by laminating and sintering each layer (active layer, suppression layer, carrier layer) proposed in Patent Document 1, and have the following technical problems. It has been found.
First, the suppression layer in the ceramic conversion element obtained by laminating and sintering each layer (active layer, suppression layer, carrier layer) described in Patent Document 1 does not function sufficiently, There has been a technical problem that the activator diffuses from the active layer to the carrier layer and diffusion reduction is not sufficient.
In particular, when the Ce concentration in the carrier layer exceeds 40 wt% of the Ce concentration in the active layer, the carrier layer also has an active (fluorescence) function, and is aimed at the light emitted from the carrier layer. It was difficult to obtain chromaticity.

Second, when the active layer is made of YAG: Ce and the suppression layer is made of Al ₂ O ₃ , the difference in refractive index between the active layer and the suppression layer becomes large. It has been found that there is a technical problem in that the amount of incident light reflected from the semiconductor body increases at the interface between the active layer and the suppression layer, and the light emission efficiency decreases due to an increase in return light.

Third, since the active layer and the carrier layer are formed of only the YAG material, the strength is low, and the difference in thermal expansion coefficient of Al ₂ O ₃ of the suppression layer interposed between the active layer and the carrier layer is small. Because of the difference, it has been found that there is a technical problem that cracking is likely to occur due to thermal stress at each interface.

Fourth, since the active layer is composed only of a YAG material, there is a technical problem that heat conductivity is low, heat generated from the semiconductor body is easily trapped in the active layer, and luminous efficiency is reduced. It has been found.
Patent Document 1 also proposes an example in which Al ₂ O ₃ particles are mixed as a scattering agent in the carrier layer, but none of the above problems can be solved effectively.

In order to solve the first to fourth technical problems described above, the present inventors have laminated and sintered each layer (active layer, suppression layer, carrier layer) proposed in Patent Document 1. The obtained ceramic conversion element was studied earnestly.
As a result, the formed intermediate layer of _Al 2 _{O 3} the diameter of the _Al 2 _{O 3} of (inhibition layer) to a specific range, in the first layer (active layer) and the second layer (carrier layer), YAG-based fluorescent The volume composition ratio of the material and Al ₂ O ₃ is in a specific range, and further, the first to fourth techniques are formed by forming a connection structure in which Al ₂ O ₃ particles are connected in each layer and in each layer interface. As a result, the present inventors have come up with the present invention.

  The present invention has been made under the circumstances as described above, and an intermediate layer between a first layer containing an activator-containing YAG-based fluorescent material and a second layer containing a YAG-based material. In the wavelength conversion laminate composite in which is disposed, the intermediate layer suppresses the diffusion of the activator from the first layer to the second layer, has high heat dissipation, and has high light of a desired hue. An object of the present invention is to provide a wavelength conversion laminate composite and a wavelength conversion laminate manufacturing method that can emit light with high luminous efficiency and have high rigidity.

The wavelength conversion laminated composite according to the present invention, which has been made to solve the above problems, includes a first layer made of an activator-containing YAG-based fluorescent material and Al ₂ O _3, and the first layer. And an intermediate layer made of Al ₂ O _{3 in} which particles having a diameter of 20 μm or more and 300 μm or less occupy 90% or more of the total number of particles, and the activator content of the first layer laminated on the intermediate layer of a second layer of 10% or less of the YAG-based material and _Al 2 _{O 3,} and the YAG fluorescent material activator-containing in the first layer, a volume composition ratio of _Al 2 _{O 3} Is in the range of 10:90 to 60:40, the volume composition ratio of the YAG-based material in the second layer to Al ₂ O ₃ is in the range of 10:90 to 40:60, and When Al ₂ O ₃ particles are connected in each layer, Furthermore, the present invention is characterized by having a connection structure in which Al ₂ O ₃ particles are connected to each other at the interface of each layer.

In this manner, in the wavelength conversion laminated composite according to the present invention, _Al in an intermediate layer formed by 2 _{O 3,} the _Al 2 _O 300 [mu] m or less in particle number diameter 20μm or more _3, the _Al 2 _{O 3} By occupying 90% or more of the total number of particles, the diffusion of the activator from the first layer to the second layer can be sufficiently reduced.
The diameter of _Al 2 _{O 3} forming the intermediate layer is preferably 5μm or 500μm or less. When the diameter of Al ₂ O ₃ forming the intermediate layer is in the range of 5 μm or more and 500 μm or less, the diffusion of the activator can be more effectively suppressed and the Al ₂ O ₃ particles become larger. The accompanying decrease in mechanical strength can be further suppressed.

The second layer is made of a YAG-based material and Al ₂ O _{3 that} are 10% or less of the activator content of the first layer, and is the same material except for the presence of the first layer and the activator. Therefore, even when the wavelength conversion laminated composite according to the present invention is used as an LED element or an LD element, the wavelength conversion accompanying the heat generation of the LED element or the LD element can be achieved. Warpage and cracking of the laminated composite can be suppressed.

In addition, when the volume composition ratio of the YAG fluorescent material containing the activator in the first layer and Al ₂ O ₃ is a, the volume composition ratio a is 10:90 or more and 60:40 or less. When the volume composition ratio of the YAG-based material in the second layer and Al ₂ O ₃ is b, the volume composition ratio b is in the range of 10:90 or more and 40:60 or less.

As described above, each of the first layer and the second layer includes Al ₂ O ₃ at a predetermined ratio, so that it has sufficient rigidity, and is caused by thermal stress at the time of use accompanying a difference in thermal expansion coefficient between the respective layers. Generation of cracks can be suppressed. Moreover, since the heat dissipation in the first layer is improved, it is possible to suppress a decrease in light emission efficiency due to hot flashing. In addition, heat dissipation to a heat sink such as an LED package can be excellent.

Furthermore, the Al ₂ O ₃ particles are connected with each other within each layer, since the Al ₂ O ₃ grains even in each layer interface has a connection structure to be connected, the light caused by the refractive index difference between the layers The amount of interface reflection can be reduced, and the decrease in luminous efficiency due to the increase in return light can be suppressed.
In addition, since the Al ₂ O ₃ particles are connected to each other, a decrease in heat generation efficiency due to heat accumulation in the first layer can be suppressed. Moreover, the heat dissipation to the device casing as a heat sink can also be improved.

Here, the average particle diameter of the YAG-based fluorescent material included in the first layer and the YAG-based material included in the second layer is not less than 0.5 μm and not more than 5 μm, and the first layer and the second layer It is desirable that the average particle diameter of Al ₂ O ₃ contained in the layer is 0.5 μm or more and 10 μm or less.
By setting the particle size as described above, the scattering property of the emitted light is improved, the color unevenness at the viewing angle can be further reduced, and in particular, the heterogeneity of the YAG-based fluorescent material in the first layer The in-plane color unevenness of the emitted light accompanying the distribution can be further reduced.

Moreover, in the wavelength conversion laminated composite of this invention, when the volume composition ratio of the activator containing YAG type fluorescent material in the said 1st layer which made the whole 100 is set to a, a is 10-30. When the volume composition ratio of the YAG-based material in the second layer, which is 100 as a whole, is b, it is more preferable that b is 20 to 40 and b is larger than the a.
By using the wavelength conversion laminate composite so that the second layer is positioned on the upper surface of the light emitting element and irradiating blue light from the light emitting element, the blue light emitted from the light emitting element is reduced in volume of the YAG-based material. When the first layer is more diffused and the first layer is irradiated with a larger composition ratio, the blue light is more uniformly diffused, and heat generation due to local irradiation unevenness can be suppressed, and the luminous efficiency can be improved. It can be improved further.

Further, the YAG fluorescent material activator-containing contained in the first _{layer, (Y 1-s Gd s} ) 3 (Al 1-t Ga t) 5 O 12: Ce (0.1 ≦ s < 1, 0.1 ≦ t <1) is desirable. With such a YAG fluorescent material, the wavelength conversion laminate composite can be more reliably produced, and the effects of the present invention described above can be made more remarkable.

Was also made in order to solve the above problems, the method for manufacturing a wavelength conversion laminated composite body according to the present invention, a first layer of YAG fluorescent material activator-containing and Al ₂ O ₃ Prefecture, the An intermediate layer made of Al ₂ O ₃ , wherein the particles having a diameter of 20 μm or more and 300 μm or less occupying 90% or more of the total number of particles, and being laminated on the intermediate layer, It is characterized by sintering in a state having a YAG-based material having a content of activator of 10% or less and a second layer made of Al ₂ O ₃ .
According to this, the spreading | diffusion to the said 2nd layer of the activator contained in a said 1st layer is suppressed, and a highly rigid wavelength conversion laminated composite can be obtained.

  According to the present invention, in the wavelength conversion laminate composite in which the intermediate layer is disposed between the first layer containing the activator-containing YAG-based fluorescent material and the second layer containing the YAG-based material, The intermediate layer suppresses the diffusion of the activator from the first layer to the second layer, has high heat dissipation, can emit light of a desired hue with high luminous efficiency, and is rigid. A high wavelength conversion laminate composite can be obtained. Further, diffusion of the activator contained in the first layer into the second layer is suppressed, and a method for producing a highly rigid wavelength conversion laminate composite is obtained.

FIG. 1 is a cross-sectional view of a wavelength conversion laminate composite according to the present invention. FIG. 2 is a cross-sectional view showing a state in which the wavelength conversion laminated composite of FIG. 1 is arranged on a light emitting element. FIG. 3 is a cross-sectional view of a conventional optoelectronic device including a phosphor that converts the wavelength of incident light. 4 is a cross-sectional view of a wavelength conversion element provided in the optoelectronic device of FIG.

Hereinafter, embodiments of a wavelength conversion laminated composite according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a wavelength conversion laminate composite 1 according to the present invention.
As shown in FIG. 1, the wavelength conversion laminate composite 1 includes a first layer 2 that performs wavelength conversion, an intermediate layer 4 that is laminated on the first layer 2, and a laminate on the intermediate layer 4. And a second layer 3 serving as a carrier layer of an LED (light emitting diode) or LD (laser diode). The first layer 2 is disposed on the beam emission surface of an LED (light emitting diode) or LD (laser diode). That is, the wavelength conversion laminated composite 1 converts light of a predetermined wavelength incident from an LED or LD into a different wavelength in the first layer 2 and emits it.

The first layer 2 has a wavelength conversion function of converting a part of excitation light (specific wavelength) from an LED (light emitting diode) or LD (laser diode) into a wavelength longer than the wavelength and transmitting it.
Specifically, it is a layer composed of a YAG-based fluorescent material (for example, YAG: Ce) containing an activator (for example, Ce) and Al ₂ O ₃ . The wavelength conversion function layer such as the first layer 2 is adjusted in the wavelength or the like for converting the excitation light according to the composition of the fluorescent material substrate, the type and content of the activator, the thickness of the layer, and the like (chromaticity Designed).
More particularly, the YAG fluorescent material of the _{activator-containing, (Y 1-s Gd s} ) 3 (Al 1-t Ga t) 5 O 12: Ce, where 0.1 ≦ s <1, 0 .Ltoreq.1 <t <1, and it is possible to more reliably produce the above-mentioned wavelength conversion laminate composite by using such a YAG-based fluorescent material, and to further enhance the effects of the present invention described later. It can be.

Moreover, as described above, the intermediate layer 4 made of Al ₂ O ₃ is provided between the first layer 2 and the second layer 3. When the intermediate layer 4 is prepared by sequentially laminating the green sheets to be the layers 2 to 4 in the production of the wavelength conversion laminate composite 1, the activator in the first layer 2 is added in the firing step. It suppresses diffusion to the second layer 3.
That is, when the activator contained in the first layer 2 diffuses into the second layer 3, the content of the activator in the first layer 2 decreases from the intended amount, and the conversion wavelength shifts. Arise. Further, since the second layer 3 is doped with the activator, the second layer 3 also partially converts the excitation light, and as a result, the overall chromaticity of the emitted light cannot be achieved as designed. The problem arises. In order to solve these problems, the intermediate layer 4 is provided.

Further, the intermediate layer 4 is formed by _Al 2 _{O 3,} the _Al 2 _O The number of particles diameter 20μm or 300μm below _3, is configured to occupy the _Al 2 _{O 3} of the total number of particles in 90% Yes.
By thus the green sheet the _Al 2 300 [mu] m or less in particle number diameter 20μm or more _{O 3} after firing step is completed the stack is fired to occupy the _Al 2 _{O 3} of the total number of particles in 90% The diffusion of the activator from the first layer to the second layer can be sufficiently reduced. In addition, it becomes possible to suppress the diffusion of the activator in the reheating process such as film formation and adhesion after firing.

The diameter of the Al ₂ O ₃ particles forming the intermediate layer 4 is more preferably 5 μm or more and 500 μm or less. If the diameter of such Al ₂ O ₃ particles, the diffusion of the activator can be more effectively suppressed, and the decrease in mechanical strength associated with the excessive particles can be suppressed. it can.
Further, Al ₂ O ₃ forming the intermediate layer 4 has a porosity of 0.1% or more and 2.0% or less, and it is more preferable that pores having a diameter of 0.3 μm or more and 3 μm or less are uniformly distributed, Thereby, the crack by thermal stress can be prevented more reliably.

The second layer 3 is made of the same material as the first layer 2 except for the presence or absence of an activator, specifically, a YAG-based material having a content of activator of the first layer 2 of 10% or less. It consists of Al ₂ O ₃ .
By forming the second layer 3 in this way, when the wavelength conversion laminated composite 1 is used as an LED lamp or an LD lamp, the occurrence of warpage of the composite accompanying the heat generation of the LED element or the LD element is suppressed. be able to.

The volume composition ratio of the activator-containing doped YAG-based fluorescent material in the first layer to Al ₂ O ₃ is in the range of 10:90 to 60:40, and the second layer The volume composition ratio between the YAG-based material and Al ₂ O _{3 in} the range of 10:90 to 40:60.
Further, the first layer 2, second layer 3, with _Al 2 _{O 3} particles are connected with each other in each layer of the intermediate layer 4, the _Al 2 _{O 3} grains even at the interface of each layer 2, 3, 4 It has a connecting structure to be connected.
That is, the wavelength conversion laminated composite 1 is a structure of the first layer 2 and second layer 3 having the above composition ratio, sandwiching the intermediate layer 4 made of Al ₂ O _3, In addition, the 3 One of the layers has a connection structure between the _Al 2 _{O 3,} and a connecting structure between the _Al 2 _{O 3} even in each layer interface.

In particular, each of the first layer 2 and the second layer 3 has sufficient strength because it contains Al ₂ O ₃ at a predetermined composition ratio, and thermal stress during use accompanying a difference in thermal expansion coefficient between the respective layers. It is possible to suppress the occurrence of cracks due to. In order to further reduce the occurrence of this crack, it is preferable to make the Al ₂ O ₃ volume composition ratio of the first layer 2 and the second layer 3 uniform within ± 5 vol%. Moreover, since the heat dissipation in the first layer is improved, it is possible to suppress a decrease in light emission efficiency due to hot flashing. In addition, heat dissipation to a heat sink such as an LED package can be excellent.

Moreover, since it has a connection structure in which Al ₂ O ₃ particles are connected to each other at the interface between the layers 2, 3, and 4, it is possible to reduce the amount of light reflected by the interface due to the difference in refractive index between the layers. As a result, a decrease in luminous efficiency can be suppressed. In addition, since the Al ₂ O ₃ particles are connected to each other, a decrease in heat generation efficiency due to heat accumulation in the first layer can be suppressed. Moreover, the heat dissipation to the device casing as a heat sink can also be improved.

  “Composition ratio (vol%) × thickness (μm) of YAG-based fluorescent material contained in the first layer 2” is A (vol% · μm), and “YAG contained in the second layer 3”. Assuming that “composition ratio (vol%) × thickness (μm) of the system material” is B (vol% · μm), A / B is more preferably 0.024 or more and 5 or less. By satisfying other conditions and further forming in this range, it is possible to more reliably reduce warpage that occurs during use. In order to further enhance this effect, the A / B is more preferably 0.083 to 0.360.

The YAG fluorescent material contained in the first layer 2 and the YAG material contained in the second layer 3 have an average particle size of 0.5 μm or more and 5 μm or less, and the first layer 2 The average particle diameter of Al ₂ O ₃ contained in the second layer 3 is 0.5 μm or more and 10 μm or less.
By setting the particle size as described above, the scattering property of the emitted light is improved, the color unevenness at the viewing angle can be further reduced, and in particular, the heterogeneity of the YAG-based fluorescent material in the first layer The in-plane color unevenness of the emitted light accompanying the distribution can be further reduced.

Moreover, when the volume composition ratio of the activator-containing YAG fluorescent material in the first layer 2 is a, a is 10 to 30, and the volume composition of the YAG material in the second layer 3 is When the ratio is b, it is more preferable that b is 20 to 40, and b is larger than the a.
2, the second layer 3 is positioned on the upper surface of the light emitting element 5 and is used so as to emit blue light from the light emitting element. When the blue light is further diffused in the second layer 3 having a large volume composition ratio of the YAG-based material and is irradiated onto the first layer 2, the blue light is more uniformly diffused and is locally irradiated. Heat generation due to unevenness can be suppressed, and luminous efficiency can be further improved.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not restrict | limited by the following Example.

(Preparation of first layer green sheet)
Cerium oxide powder with an average particle size of 0.3 to 1.5 μm and purity of 99.9%, yttrium oxide powder with an average particle size of 0.6 to 5 μm and purity of 99.9%, and an average particle size of 0.2 to 0.001. A predetermined amount of 9 μm-purified aluminum oxide powder having a purity of 99.9% was blended so as to have a composition after firing under the firing conditions described later as shown in Table 1 to obtain a raw material powder.
Ethanol, a PVB binder and a glycerin plasticizer were added to the raw material powder to the raw material powder, and pulverized and mixed by a ball mill using aluminum oxide balls for 10 hours to prepare a slurry.
And the green sheet of the predetermined thickness shown in Table 1 was produced from the obtained slurry by the doctor blade method. Next, the produced green sheet was punched into a 100 mm mouth.

(Production of intermediate layer green sheet)
An aluminum oxide powder having an average particle size of 0.3 to 2.1 μm and a purity of 99.9% was used as a raw material powder. It selected so that the diameter of the aluminum oxide particle after baking on the baking conditions etc. which are described later may become in the range of the minimum value shown in Table 1, and the minimum value.
Ethanol, PVB binder and glycerin plasticizer were added to the raw material powder to this raw material powder, and pulverized and mixed for 10 hours by a ball mill using aluminum oxide balls to prepare a slurry.
And the green sheet of the predetermined | prescribed thickness shown in Table 2 was produced from the obtained slurry by the doctor blade method. Next, the produced green sheet was punched into a 100 mm mouth.

(Preparation of second layer green sheet)
An yttrium oxide powder having a purity of 99.9% and an average particle diameter of 0.6 to 5 μm, and an aluminum oxide powder having a purity of 99.9% and an average particle diameter of 0.2 to 0.9 μm, as shown in Table 1, A predetermined amount was blended so as to obtain a composition after firing under the firing conditions to be described to obtain a raw material powder.
Ethanol, a PVB binder and a glycerin plasticizer were added to the raw material powder to the raw material powder, and pulverized and mixed by a ball mill using aluminum oxide balls for 10 hours to prepare a slurry.
And the green sheet of the predetermined thickness shown in Table 3 was produced from the obtained slurry by the doctor blade method. Next, the produced green sheet was punched into a 100 mm mouth.

(Creation of wavelength conversion laminate composite)
After punching the first layer, the intermediate layer, and the second layer, the green sheet for the intermediate layer is sandwiched between the green sheet for the first layer and the green sheet for the second layer. The laminate was made.
Subsequently, a warm isostatic pressing method (WIP) was performed in an atmosphere of 60 ° C. and 100 MPa to produce a molded body having a laminated structure.
And the produced molded object was sintered at 1550-1750 degreeC in vacuum atmosphere after degreasing calcining in air | atmosphere, and the wavelength conversion laminated composite was obtained (Example 1- Example 17, Comparative Examples 1-5). ).

[Measurement and evaluation of each example and each comparative example]
(Presence or absence of connection between Al ₂ O ₃ particles)
Each example, each comparative example, connexion was verified whether the connection between the Al ₂ O ₃ particles in each layer and each layer interface.
The presence or absence of connection between Al ₂ O ₃ particles at each layer and each layer interface was determined by observing an arbitrary vertical cross section in the thickness direction of the wavelength conversion laminate composite with an SEM (scanning electron microscope), and Al _{2 at} each layer and each layer interface. It was confirmed whether or not O ₃ particles were connected (bonded). The results are shown in Table 4.

(Measurement of the number of Al ₂ O ₃ particles and each particle size)
When an arbitrary vertical cross section in the thickness direction of the wavelength conversion laminate composite is observed with an SEM (scanning electron microscope) and the intermediate layer portion is imaged with a total viewing angle of 1 mm ² , the number of Al ₂ O ₃ particles and each particle The diameter was measured.

(Measurement of Ce concentration (atom%) in first layer and second layer after firing)
The Ce concentration (atom%) in the first layer and the second layer after firing was measured by ICP emission analysis after each layer was cut out by grinding.

(Measurement of uneven color)
Color unevenness is processed into 1 mm square, irradiated with blue LED light condensed to a diameter of 0.3 mm from the back, and received from the front using a spectroscope ("USB4000 Fiber Melch Channel Spectrometer" manufactured by Ocean Optics). .
CIEx was calculated from the obtained spectrum data. The values shown in Table 5 indicate standard deviations when measuring 51 × 51 (2601 points) at a 0.1 mm pitch in a 5 mm square area.

(Measurement of chromaticity and luminous efficiency)
The chromaticity and luminous efficiency were processed to 1 mm square and then fixed with a silicone resin on a blue LED element (light emitting area 1 mm square, emission wavelength 460 nm). After collecting the luminescence with an integrating sphere, the emission spectrum was measured using a spectroscope (“USB4000 Fiber Melch Channel Spectrometer” manufactured by Ocean Optics).
The emission intensity normalized by the measurement of the fluorescence peak wavelength and the amount of absorption was calculated from the obtained spectrum. The fluorescence peak wavelength becomes shorter as Ce diffuses in the second layer. In order to obtain desired white light (8000 K or less) in combination with blue light, the emission peak wavelength needs to be 540 nm or more.
Luminous intensity (luminous efficiency) was set to 100 as a measurement result of a commercially available YAG: Ce phosphor (“P46-Y3” manufactured by Kasei Optonix).

(Warming / cracking status)
The confirmation of the state of warping / cracking was conducted by heating the wavelength conversion laminated composite cut out to 30 mm to 200 ° C. and then dropping it into water at 0 ° C. to confirm whether warpage / cracking occurred. The measurement results are shown in Table 5.
The A / B of Comparative Example 3 is 0.178, and the A / B of Comparative Example 5 is 0.171. However, since other conditions are not satisfied, warpage and cracking occur.

As a result of the above examples, as in Examples 1 to 17, particles having a diameter of 20 μm or more and 300 μm or less occupy 90% or more of the total number of particles in the intermediate layer formed of Al ₂ O ₃ . It has been confirmed that the Ce (activator) concentration in the second layer can be made sufficiently low, and the diffusion of Ce (activator) into the second layer can be suppressed.
In addition, the volume composition ratio of the activator-containing YAG-based fluorescent material in the first layer and Al ₂ O ₃ is in the range of 10:90 to 60:40, and the YAG-based material in the second layer It was confirmed that high luminous efficiency was obtained when the volume composition ratio with Al ₂ O ₃ was in the range of 10:90 or more and 40:60 or less.
In addition, the average particle size of the YAG-based fluorescent material included in the first layer and the YAG-based material included in the second layer is not less than 0.5 μm and not more than 5 μm, and the first layer, the second layer, In the range where the average particle diameter of Al ₂ O ₃ contained in the layer is 0.5 μm or more and 10 μm or less, the scattering property of the emitted light becomes good, the color unevenness at the viewing angle is reduced, and particularly the YAG system in the first layer It was confirmed that the in-plane color unevenness of the emitted light due to the heterogeneous distribution of the fluorescent material is further reduced.

DESCRIPTION OF SYMBOLS 1 Wavelength conversion laminated composite 2 1st layer 3 2nd layer 4 Intermediate | middle layer 5 LED element

Claims (5)

A first layer composed of an activator-containing YAG-based fluorescent material and Al ₂ O ₃ ;
An intermediate layer made of Al ₂ O ₃ laminated on the first layer, and particles having a diameter of 20 μm or more and 300 μm or less occupying 90% or more of the total number of particles;
A second layer made of Al ₂ O ₃ and a YAG-based material that is laminated on the intermediate layer and is 10% or less of the content of the activator of the first layer;
The volume composition ratio between the activator-containing YAG-based fluorescent material in the first layer and Al ₂ O ₃ is in the range of 10:90 to 60:40,
The volume composition ratio between the YAG-based material in the second layer and Al ₂ O ₃ is in the range of 10:90 or more and 40:60 or less,
And, together with the Al ₂ O ₃ particles are connected with each other within each layer, the wavelength conversion laminated composite, characterized in that the Al ₂ O ₃ grains even in each layer interface has a connection structure to be connected. The average particle size of the YAG-based fluorescent material contained in the first layer and the YAG-based material contained in the second layer is 0.5 μm or more and 5 μm or less,
2. The wavelength conversion laminate composite according to claim 1, wherein an average particle diameter of Al ₂ O ₃ contained in the first layer and the second layer is 0.5 μm or more and 10 μm or less.   When the volume composition ratio of the activator-containing YAG-based fluorescent material in the first layer as a whole is 100, a is 10 to 30, and the whole is 100 in the second layer. 3. The wavelength conversion laminated composite according to claim 1, wherein when the volume composition ratio of the YAG-based material is b, b is 20 to 40, and b is larger than the a. body. The YAG fluorescent material activator-containing contained in the first _{layer, (Y 1-s Gd s} ) 3 (Al 1-t Ga t) 5 O 12: Ce (0.1 ≦ s <1, The wavelength conversion laminated composite according to any one of claims 1 to 3, wherein 0.1≤t <1). A first layer composed of an activator-containing YAG-based fluorescent material and Al ₂ O ₃ ;
An intermediate layer made of Al ₂ O ₃ laminated on the first layer, and particles having a diameter of 20 μm or more and 300 μm or less occupying 90% or more of the total number of particles;
It is laminated on the intermediate layer, and is sintered in a state having a YAG-based material of 10% or less of the activator content of the first layer and a second layer made of Al ₂ O _3. The manufacturing method of the wavelength conversion laminated composite which performs.

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