WO2013129477A1

WO2013129477A1 - Wavelength conversion member and semiconductor light-emitting device using same

Info

Publication number: WO2013129477A1
Application number: PCT/JP2013/055140
Authority: WO
Inventors: 覚成勝本; 敏明横尾; 弘也樹神; 宏之伊村; 政巳鈴木; 山本　大輔
Original assignee: 三菱化学株式会社
Priority date: 2012-02-27
Filing date: 2013-02-27
Publication date: 2013-09-06
Also published as: JP2014039006A; TW201347242A

Abstract

The present invention addresses the problem of providing a wavelength conversion member which, when provided on a semiconductor light-emitting device, decreases the contained amount of fluorescent body and thus achieves cost reduction without decreasing the light-emission efficiency of the semiconductor light-emitting device, and a semiconductor light-emitting device using the wavelength conversion member. The problem can be solved by a wavelength conversion member which converts the wavelength of at least part of incident light and emits outgoing light with a wavelength different from the wavelength of the incident light, wherein the wavelength conversion member includes a fluorescent body for absorbing at least part of said incident light and emitting outgoing light with a wavelength different from the wavelength of said incident light, a light diffusion element for diffusing said incident light and said outgoing light, and a base material for holding said light diffusion element, and satisfies the following formula: 0.01 ≤ |(refractive index of light diffusion element) − (refractive index of base material)| × (thickness of wavelength conversion member [mm]) × (volume fraction of light diffusion element [vol%]) ≤ 1.0.

Description

Wavelength converting member and semiconductor light emitting device using the same

The present invention relates to a wavelength conversion member that converts the wavelength of at least part of incident light and emits outgoing light having a wavelength different from that of the incident light, and a semiconductor light emitting device using the wavelength conversion member and a semiconductor light emitting element.

Incandescent bulbs and fluorescent lamps have been widely used as light sources for light-emitting devices. In recent years, in addition to these, semiconductor light-emitting devices that use semiconductor light-emitting elements such as light-emitting diodes (LEDs) and organic ELs (OLEDs) as light sources have been developed and used. Since these semiconductor light emitting elements can obtain various emission colors, a plurality of semiconductor light emitting elements having different emission colors are combined, and the respective emission colors are combined to obtain a combined light of a desired color. Such semiconductor light emitting devices have been developed and used.

For example, a red LED using an LED chip whose emission color is red, a green LED using an LED chip whose emission color is green, and a blue LED using an LED chip whose emission color is blue are combined and supplied to each LED. Japanese Patent Application Laid-Open No. 2004-151867 discloses a semiconductor light emitting device that emits desired white light by adjusting the driving current to be synthesized and combining the light emitted from each LED.

Originally, since the emission spectrum width of the LED chip itself is relatively narrow, when light emitted from the LED chip itself is used for illumination as it is, there is a problem that color rendering, which is important in general illumination light, is reduced. Therefore, in order to solve such problems, an LED has been developed in which the light emitted from the LED chip is wavelength-converted by a wavelength conversion member such as a phosphor, and the light obtained by the wavelength conversion is emitted. A semiconductor light emitting device combining LEDs is disclosed in, for example, Patent Document 2.

In the semiconductor light emitting device disclosed in Patent Document 2, a transparent resin is provided so as to cover an LED chip that emits blue light while being in contact with it, and a yellow phosphor is contained inside the transparent resin. That is, the semiconductor light emitting device disclosed in Patent Document 2 is provided with a wavelength conversion member so as to directly cover the LED chip. However, in the semiconductor light emitting device having such a structure, variations in luminance and color unevenness of the semiconductor light emitting device are large. In order to solve such problems, research and development and commercialization of a semiconductor light emitting device having a structure in which a resin containing a phosphor (that is, a wavelength conversion member) is arranged apart from an LED chip have been actively performed in recent years. Has been done. A semiconductor light emitting device having such a structure is disclosed in Patent Document 3, for example.

JP 2006-4839 A JP 2007-122950 A JP 2011-159813 A

However, the structure in which the wavelength conversion member is provided apart from the LED chip is larger in the size of the wavelength conversion member than the structure in which the wavelength conversion member is provided so as to cover the LED chip so as to cover the LED chip. The amount of phosphor produced is increased. In general, when the wavelength conversion member is separated from the LED chip, a phosphor several times more than the conventional phosphor is required to obtain the same light emission efficiency as when the LED chip is directly covered with the wavelength conversion member. It becomes. Therefore, it is required to reduce the amount of phosphor used for the wavelength conversion member.

Therefore, in the semiconductor light emitting device having a structure in which the wavelength conversion member is provided apart from the LED chip, there is a problem that the amount of the phosphor is increased as compared with the conventional case, and the cost of the wavelength conversion member and the semiconductor light emitting device is increased. . In particular, when a single wavelength conversion member is provided for a large number of LED chips, the product cost has increased.

The present invention has been made in view of such problems, and the object of the present invention is to provide a phosphor content without reducing the light emission efficiency of the semiconductor light emitting device when provided in the semiconductor light emitting device. It is providing the wavelength conversion member which can aim at cost reduction by reducing, and the semiconductor light-emitting device using the said wavelength conversion member.

In order to achieve the above object, the wavelength conversion member of the present invention is a wavelength conversion member that emits outgoing light having a wavelength different from that of the incident light by converting the wavelength of at least part of the incident light. A phosphor that absorbs at least a portion and emits outgoing light having a wavelength different from that of the incident light; a light diffusion element that diffuses the incident light and the outgoing light; and a base material that holds the light diffusion element; Including
0.01 ≦ | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength conversion member [mm]) × (volume fraction of light diffusing element [vol%]) ≦ 1. 0
It satisfies the following formula.

In the wavelength conversion member described above, | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength converting member [mm]) × (volume fraction of light diffusing element) in the above formula. The value of [vol%] is preferably 0.6 or less, and more preferably 0.2 or less.

In the wavelength conversion member described above, the value of | (refractive index of light diffusing element) − (refractive index of base material) | in the above formula is preferably 0.07 or more.

Further, in the above-described wavelength conversion member, the phosphor content concentration [wt%] when a wavelength conversion member that does not include the light diffusing element and emits emitted light of the same chromaticity is created as a reference. The decreasing rate of the phosphor concentration (wt%) may be 3.0% to 86%.

In the wavelength conversion member described above, | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength converting member [mm]) × (volume fraction of light diffusing element) [Vol%]) is preferably 0.04 or more, and more preferably 0.05 or more.

The wavelength conversion member described above is
28 ≤ dy / dx ≤ 447
x: | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength conversion member [mm]) × (volume fraction of light diffusing element [vol%])
y: Concentration [wt] of the phosphor based on the concentration [wt%] of the phosphor when a wavelength conversion member that emits outgoing light of the same chromaticity without including the light diffusing element is created. %] Reduction ratio may be satisfied.

In the wavelength conversion member described above, the phosphor and the light diffusing element may be mixed in the base material. The phosphor and the light diffusing element may be separately contained in the base material, and may form a phosphor layer and a light diffusing layer. In this case, the phosphor layer and the light diffusion layer may be laminated while being in contact with each other, or the base material has a void layer that separates the phosphor layer and the light diffusion layer. It may be.

In the wavelength conversion member described above, it is preferable that a refractive index of the light diffusing element is 1.0 or more and 1.9 or less, and a refractive index of the base material is 1.3 or more and 1.7 or less.

In the wavelength conversion member described above, the light diffusing element is preferably an inorganic light diffusing material or an organic light diffusing material containing at least one element of the group consisting of silicon, aluminum, titanium, and zirconium. . In this case, the organic light diffusing material is more preferably an organic light diffusing material containing silicon as an element or an acrylic light diffusing material.

In the wavelength conversion member described above, the light diffusing element may be formed of bubbles.

In the wavelength conversion member described above, it is preferable that the base material is made of resin or glass. In this case, it is more preferable that the resin is at least one resin selected from the group consisting of a polycarbonate resin, a polyester resin, an acrylic resin, an epoxy resin, and a silicone resin.

In the wavelength conversion member described above, it is more preferable that the base material is polycarbonate resin and the light diffusion element is polymethylsilsesquioxane particles.

In order to achieve the above object, a semiconductor light emitting device of the present invention includes a wiring board, a semiconductor light emitting element disposed on a mounting surface of the wiring board, and wavelength conversion of at least a part of incident light. A semiconductor light emitting device including a wavelength conversion member that emits emitted light of different wavelengths,
The wavelength conversion member includes a phosphor that absorbs at least a part of incident light and emits outgoing light having a wavelength different from that of the incident light, a light diffusion element that diffuses the incident light and the outgoing light, and the light. And a base material holding the diffusing element, and 0.01 ≦ | (refractive index of the light diffusing element) − (refractive index of the base material) | × (thickness of wavelength conversion member [mm]) × (light diffusion) Element volume fraction [vol%]) ≦ 1.0
It satisfies the following formula.

In the semiconductor light emitting device described above, | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength conversion member [mm]) × (volume fraction of light diffusing element) in the above formula. The value of [vol%] is preferably 0.6 or less, and preferably 0.2 or less.

In the semiconductor light emitting device described above, the value of | (refractive index of light diffusing element) − (refractive index of base material) | in the above formula is preferably 0.07 or more.

In the semiconductor light emitting device described above, the light emission efficiency (lm / W) maintenance rate is 90% or more on the basis of the light emission efficiency (lm / W) when the light diffusion element is not included, and the light diffusion element The content concentration [wt%] of the phosphor may be reduced as compared with the case where no phosphor is included.

In the semiconductor light emitting device described above, the semiconductor light emitting element and the wavelength conversion member may be separated from each other.

Furthermore, in the semiconductor light emitting device described above, the phosphor and the light diffusing element may be mixed in the base material. In the semiconductor light emitting device described above, the phosphor and the light diffusing element may be contained separately from each other in the base material and may have a laminated structure including a phosphor layer and a light diffusing layer. . In such a case, the distance from the semiconductor light emitting element to the phosphor layer may be smaller or larger than the distance from the semiconductor light emitting element to the light diffusion layer.

In the semiconductor light emitting device described above, it is preferable that a refractive index of the light diffusing element is 1.0 or more and 1.9 or less, and a refractive index of the base material is 1.3 or more and 1.7 or less.

In the semiconductor light emitting device described above, the base material is preferably made of resin or glass. In this case, it is more preferable that the resin is at least one resin selected from the group consisting of a polycarbonate resin, a polyester resin, an acrylic resin, an epoxy resin, and a silicone resin.

In the semiconductor light emitting device described above, it is more preferable that the base material is polycarbonate resin and the light diffusion element is polymethylsilsesquioxane particles.

In the semiconductor light emitting device described above, the light emitted from the semiconductor light emitting element that has not been wavelength-converted by the wavelength conversion member and the light converted by the wavelength conversion member may be mixed to emit white light.
In the semiconductor light emitting device described above, a mode in which a reflector is provided on the wiring substrate and the area of the portion having a reflectance of 80% or more is 50% or more of the area on the wiring substrate is preferable.
Further, the semiconductor light emitting device described above has a frame body, and a reflector is provided on the wiring board and the wall surface in the frame, and the area of the part having a reflectance of 80% or more is on the wall surface in the frame and the wall surface. The aspect which is 50% or more of the area on a wiring board is preferable.

In order to achieve the above object, a semiconductor light emitting device of the present invention includes a wiring board, a semiconductor light emitting element disposed on a mounting surface of the wiring board, and wavelength conversion of at least a part of incident light. A semiconductor light emitting device including a wavelength conversion member that emits emitted light of different wavelengths,
The wavelength conversion member includes a phosphor that absorbs at least a part of incident light and emits outgoing light having a wavelength different from that of the incident light, a light diffusion element that diffuses the incident light and the outgoing light, and the light. And a base material holding the diffusing element, and 0.01 ≦ | (refractive index of the light diffusing element) − (refractive index of the base material) | × (thickness of wavelength conversion member [mm]) × (light diffusion) Element volume fraction [vol%]) ≦ 1.0
Satisfy the formula of
The (volume fraction [vol%] of the light diffusing element) in the above formula uses the image analysis result of the cross-sectional SEM image of the wavelength conversion member,
C = N × 4π / 3 × (D / 2) ³ / (S × D) × 100
C: Volume fraction [vol%] of the light diffusing element
N: Total number of light diffusing elements in the wavelength conversion member calculated by binarization processing of the cross-sectional SEM image [pieces]
D: of the light diffusing element obtained by multiplying the average diameter of the circle calculated by assuming the circle from the average area of the light diffusing element in the cross-sectional SEM image calculated by the binarization processing of the cross-sectional SEM image by π / 4 Particle size [μm]
S: Total area of cross-sectional SEM image [μm ² ]
It is calculated from the following formula.

In the wavelength conversion member of the present invention, 0.01 ≦ | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength converting member [mm]) × (volume of light diffusing element) Rate [vol%]) ≦≦ 1.0 satisfies the mathematical formula, so that when the semiconductor light emitting device is provided in the semiconductor light emitting device, the phosphor content is reduced without reducing the light emitting efficiency of the semiconductor light emitting device. Reduction can be achieved. This is presumably because the ratio of the light emitted from the semiconductor light emitting element subjected to wavelength conversion per unit weight of the phosphor contained in the wavelength conversion member can be increased. In this case, the value of | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength conversion member [mm]) × (volume fraction of light diffusing element [vol%]) is If it is 0.6 or less, the effect (reduction in luminous efficiency and cost reduction) is remarkably exhibited, and if it is 0.2 or less, the effect is remarkably exhibited.

In the wavelength conversion member of the present invention, | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength converting member [mm]) × (volume fraction of light diffusing element [ vol%]) is 0.02 or more, it is possible to reduce the variation in the luminous efficiency of the semiconductor light emitting device due to the variation in the phosphor content. As a result, the conversion efficiency of the light emitted from the semiconductor light emitting element changes, so that the light emitted from the semiconductor light emitting element (for example, blue light) and the light converted by the wavelength conversion member (for example, yellow) Variation in chromaticity of light (for example, white light) emitted from the semiconductor light emitting device by mixing with the light. In this case, the value of | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength conversion member [mm]) × (volume fraction of light diffusing element [vol%]) is If it is 0.04 or more, the effect (reduction in variation in light emission efficiency) is remarkably exhibited, and if it is 0.05 or more, the effect is remarkably exhibited.

Further, in the semiconductor light-emitting device of the present invention, the wavelength conversion member is 0.01 ≦≦ | (refractive index of the light diffusing element) − (refractive index of the base material) | × (thickness [mm] of the wavelength conversion member) × (Volume volume ratio of light diffusing element [vol%]) ≤ Since 1.0 is satisfied, the phosphor content can be reduced and the cost can be reduced without lowering the luminous efficiency.

Then, when verifying and evaluating the wavelength conversion member included in the semiconductor light emitting device, (the volume fraction [vol%] of the light diffusing element) in the above-described formula is used as the image analysis result of the cross-sectional SEM image of the wavelength conversion member. , C = N × 4π / 3 × (D / 2) ³ / (S × D) × 100 (where C: volume fraction of light diffusing element [vol%], N: binarization of cross-sectional SEM image) The total number of light diffusing elements in the wavelength conversion member calculated by the processing [D], D: assuming a circle from the average area of the light diffusing elements in the cross-sectional SEM image calculated by the binarization processing of the cross-sectional SEM image By calculating using the mathematical formula of the particle diameter [μm] of the light diffusing element obtained by multiplying the calculated average diameter of the circle by π / 4, S: the total area [μm ² ] of the cross-sectional SEM image), High precision equivalent to the case of verification and evaluation using the true volume fraction of the light diffusing element It is possible to realize a Do verification and evaluation.

1 is a perspective view showing an outline of an overall configuration of a semiconductor light emitting device according to a first embodiment. 1 is a plan view of a semiconductor light emitting device according to a first embodiment. FIG. 3 is a cross-sectional view of the semiconductor light emitting device taken along line III-III in FIG. 2. It is an expanded sectional view of the principal part in FIG. It is a graph which shows the result of the simulation in the semiconductor light-emitting device concerning a 1st embodiment. It is a graph which shows the result of the simulation in the semiconductor light-emitting device concerning a 1st embodiment. It is the expanded sectional view which showed the principal part of the semiconductor light-emitting device concerning 2nd Embodiment similarly to FIG. It is the expanded sectional view of the other aspect which showed the principal part of the semiconductor light-emitting device concerning 2nd Embodiment similarly to FIG. FIG. 5 is an enlarged cross-sectional view showing a main part of a semiconductor light emitting device according to a third embodiment in the same manner as FIG. It is the expanded sectional view of the other aspect which showed the principal part of the semiconductor light-emitting device concerning 3rd Embodiment similarly to FIG. In Example 2, the change in the amount of phosphor used when the value of [(refractive index of light diffusing element−refractive index of base material) × thickness of wavelength converting member × volume fraction of light diffusing element] was changed. It is a graph which shows the change of luminous flux value. It is a conceptual diagram which shows the structure of the semiconductor light-emitting device which concerns on the embodiment of this invention. It is a conceptual diagram which shows the structure of the semiconductor light-emitting device which concerns on the embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail based on some embodiments with reference to the drawings. In addition, this invention is not limited to the content demonstrated below, In the range which does not change the summary, it can change arbitrarily and can implement. The drawings used for describing each embodiment schematically show a semiconductor light emitting device according to the present invention, and are partially emphasized, enlarged, reduced, or omitted to deepen understanding. In some cases, it does not accurately represent the scale or shape of each component. Furthermore, all the various numerical values used in each embodiment show an example, and can be changed variously as necessary.

<First Embodiment>
(Configuration of semiconductor light emitting device)
FIG. 1 is a perspective view schematically showing the overall configuration of the semiconductor light emitting device 1 according to the first embodiment, and FIG. 2 is a plan view of the semiconductor light emitting device 1 of FIG. 1 and 2, one direction in the plan view of the semiconductor light emitting device 1 is the X direction, the direction orthogonal to the X direction in the plan view is the Y direction, and the height direction of the semiconductor light emitting device 1 (the wiring board method). Line direction) is defined as the Z direction.

In this embodiment, the semiconductor light emitting device 1 is a light source that emits pseudo white light. As shown in FIG. 1, the semiconductor light-emitting device 1 is a wiring board made of an alumina-based ceramic having excellent electrical insulation, good heat dissipation, and high reflectivity (preferably reflectivity of 80% or more). 2 is provided. On the chip mounting surface 2 a of the wiring substrate 2, four light emitting diode (LED: Light Emitting Diode) chips 3, which are a total of twelve semiconductor light emitting elements, four in the X direction and three in the Y direction are arranged. Although not shown in FIG. 1, a wiring pattern for supplying power to each of these LED chips 3 is formed on the wiring board 2 to constitute an electric circuit.

Note that the material of the wiring board 2 is not limited to alumina-based ceramics. For example, a material selected from resin, glass epoxy, a composite resin containing a filler in the resin, and the like as a material excellent in electrical insulation. You may form the main body of the wiring board 2 using. Alternatively, in order to improve the light reflectivity on the chip mounting surface 2a of the wiring board 2 and improve the light emission efficiency of the semiconductor light emitting device 1, silicone containing white pigment such as alumina powder, silica powder, magnesium oxide, titanium oxide or the like is used. It is preferable to use a resin. On the other hand, in order to obtain more excellent heat dissipation and reflectivity, the main body of the wiring board 2 may be made of metal such as silver. In such a case, it is necessary to electrically insulate the wiring pattern of the wiring board 2 from the metal body.

From the viewpoint of improving the light emission efficiency of the semiconductor light emitting device 1, the chip mounting surface 2a of the wiring board 2 preferably has a part with a reflectance of 90% or more, and the area of the part with a reflectance of 90% or more is 50%. More preferably, it is more preferably 70% or more, and particularly preferably 80% or more.
In addition, a reflectance means the reflectance of visible region light.
An example of a material for achieving such a reflectance is a reflective material in which a filler is contained in a resin. Specifically, metal oxides are contained in reflectors and ceramics that contain metal oxide fillers such as alumina, titania, silicon oxide, zinc oxide, magnesium oxide in silicone resin, polycarbonate resin, polyphthalamide resin, etc. A reflective material or the like is preferable.
Examples of the reflective material containing a metal oxide such as titania in polycarbonate resin include Iupilon EHR3100 and EHR3200.
Examples of the reflective material in which a metal oxide such as alumina or titania is contained in a silicone resin include the reflective materials described in WO2011 / 078239 and WO2011 / 136302.
Moreover, a reflective material in which a metal oxide such as alumina or titania is contained in polyphthalamide is also preferably exemplified.

Further, as shown in FIG. 1, on the chip mounting surface 2a of the wiring board 2 on which the LED chip 3 is mounted, at least part of incident light incident from the LED chip 3 is wavelength-converted to a different wavelength, and the wavelength conversion is performed. A wavelength conversion member 4 that emits the emitted light as emitted light to the outside of the semiconductor light emitting device 1 is disposed. The shape of the wavelength converting member 4 is hemispherical and has a dome shape (that is, a bowl shape) in which a gap is formed. The wavelength conversion member 4 is separated from the twelve LED chips 3 and covers all the LED chips 3.

FIG. 3 is a cross-sectional view of the semiconductor light emitting device 1 taken along the line III-III in FIG. 2, and FIG. 4 is an enlarged view of a main part of the cross-sectional view shown in FIG. Hereinafter, the LED chip 3 and the wavelength conversion member 4 will be described in detail with reference to FIGS. 3 and 4.

(LED chip)
In the present embodiment, an LED chip that emits blue light having a peak wavelength of 460 nm is used as the LED chip 3. Specifically, as such an LED chip, for example, there is a GaN-based LED chip in which an InGaN semiconductor is used for a light emitting layer. Note that the type and emission wavelength characteristics of the LED chip 3 are not limited thereto, and various semiconductor light emitting elements such as LED chips can be used without departing from the gist of the present invention. In this embodiment, the peak wavelength of the light emitted from the LED chip 3 is preferably in the wavelength range of 360 nm to 480 nm, and more preferably in the wavelength range of 390 nm to 430 nm or in the wavelength range of 430 nm to 480 nm.

As shown in FIG. 4, a p-electrode 5 and an n-electrode 6 are provided on the surface of the LED chip 3 facing the wiring board 2 side. In the case of the LED chip 3 shown in FIG. 4, the p-electrode 5 is bonded to the wiring pattern 7 formed on the chip mounting surface 2a of the wiring board 2, and the wiring pattern 8 also formed on the chip mounting surface 2a is n. The electrode 6 is joined. The p electrode 5 and the n electrode 6 are connected to the wiring pattern 7 and the wiring pattern 8 by soldering via metal bumps (not shown). Other LED chips 3 (not shown) are also bonded to the wiring pattern formed on the chip mounting surface 2a of the wiring board 2 corresponding to each LED chip 3 in the same manner. Has been. Here, the LED chips 3 may be connected in series via the wiring pattern 7 and the wiring pattern 8, may be connected in parallel, and is further connected in a combination of serial connection and parallel connection. Also good.

In addition, the mounting method of the LED chip 3 on the wiring board 2 is not limited to this, and an appropriate method can be selected according to the type and structure of the LED chip 3. For example, after the LED chip 3 is bonded and fixed to a predetermined position of the wiring board 2, two electrodes of each LED chip 3 may be connected to a corresponding wiring pattern by wire bonding, or one electrode may be connected as described above. While joining to a corresponding wiring pattern, you may make it connect the other electrode to a corresponding wiring pattern by wire bonding.

(Wavelength conversion member)
As described above, the wavelength conversion member 4 converts the wavelength of a part of incident light emitted from the LED chip 3 and emits outgoing light having a wavelength different from that of the incident light. As a more specific configuration, the wavelength conversion member 4 absorbs and excites incident light emitted from the LED chip 3, and emits outgoing light having a wavelength different from the incident light when returning to the ground state. 4a, the light diffusing element 4b that diffuses the emitted light emitted from the phosphor 4a and guides it to the emitting surface side of the semiconductor light emitting device 1, the phosphor 4a and the light diffusing element 4b are dispersed and held, and wavelength conversion is performed. It has resin 4c which functions as a base material of member 4. FIG. 4 is an enlarged view of a main part of a cross-sectional view of the semiconductor light emitting device 1 when a resin is used as a base material. In the wavelength conversion member 4 in the present embodiment of FIG. The light diffusing element 4b is mixed.

Further, in the semiconductor light emitting device 1 of the present embodiment, since the wavelength conversion member 4 is separated from the LED chip, the wavelength conversion member 4 is not heated by the heat generated by the LED chip 3, and the wavelength conversion member 4 is not heated. The wavelength conversion function and the light emission efficiency of the semiconductor light emitting device 1 are prevented from decreasing. In the present embodiment, the wavelength conversion member 4 is separated from the LED chip 3 by about 25 mm. In the aspect in which the wavelength conversion member and the LED chip are separated from each other, the separation distance is appropriately set depending on the size of the device and the like, and is usually 1 mm or more, preferably 5 mm or more, and usually 500 mm or less, preferably 300 mm or less.

[Phosphor]
In this embodiment, since the LED chip 3 that emits blue light is used as a semiconductor light emitting element, in order to obtain white light from the semiconductor light emitting device 1, a part of the blue light is wavelength-converted to yellow light. It is necessary to synthesize white light by mixing the yellow light and the blue light that has not been wavelength-converted. Therefore, a yellow phosphor that converts the wavelength of blue light into yellow light is used as the phosphor 4a in the present embodiment.

In addition, in order to adjust the chromaticity and color temperature of white light or to improve color rendering, a part of the blue light may be wavelength-converted into red light or green light. In this case, a red phosphor or a green phosphor can be used in addition to the yellow phosphor, or a red phosphor and a green phosphor can be used instead of the yellow phosphor.

The emission peak wavelength of a specific yellow phosphor is usually 530 nm or more, preferably 540 nm or more, more preferably 550 nm or more, and usually 620 nm or less, preferably 600 nm or less, more preferably 580 nm or less. Is preferred. Among them, as the yellow phosphor, for example, Y ₃ Al ₅ O ₁₂ : Ce [YAG phosphor], Lu ₃ Al ₅ O ₁₂ : Ce [LuAG phosphor], (Y, Gd) ₃ Al ₅ O ₁₂ : Ce, ( Sr, Ca, Ba, Mg) ₂ SiO ₄ : Eu, (Ca, Sr) Si ₂ N ₂ O ₂ : Eu, α-sialon, La ₃ Si ₆ N ₁₁ : Ce (provided that some of them are Ca or O Is optionally substituted).

When a red phosphor is used, the emission peak wavelength is usually in the wavelength range of 565 nm or more, preferably 575 nm or more, more preferably 580 nm or more, and usually 780 nm or less, preferably 700 nm or less, more preferably 680 nm or less. Is preferred. Examples of such red phosphors are, for example, CaAlSiN ₃ : Eu [CASN phosphor] described in JP-A-2006-008721 and JP-A-2008-7751 (Sr, Ca ) AlSiN ₃ : Eu [SCASN phosphor], Ca _1-x Al _1-x Si _{1 + x} N _3-x O _x : Eu [CASON phosphor] and the like described in JP-A-2007-231245 Use active oxide, nitride or oxynitride phosphor, 3.5MgO · 0.5gF ₂ · GeO ₂ : Mn activated germanate phosphor such as Mn, Mn ⁴⁺ activated fluoride complex phosphor, etc. Is also possible.

In the case of using a green phosphor, the emission peak wavelength is usually larger than 500 nm, preferably 510 nm or more, more preferably 515 nm or more, and usually 550 nm or less, especially 540 nm or less, further 535 nm or less. It is preferable that If this emission peak wavelength is too short, it tends to be bluish, while if it is too long, it tends to be yellowish, and there is a possibility that the characteristics as green light will deteriorate. As such a green phosphor, for example, Y ₃ (Al, Ga) ₅ O ₁₂ : Ce [G-YAG phosphor], described in International Publication No. 2007/091687 (Ba, Ca, Sr, Mg) ₂ SiO ₄ : Eu-activated alkaline earth silicate phosphor represented by Eu [BSS phosphor], Si _6-z Al _z N _8-z O _z described in Japanese Patent No. 3911545 : Eu-activated oxynitride phosphor [β-SiAlON phosphor] such as Eu (where 0 <z ≦ 4.2), M ₃ Si described in International Publication No. 2007/088966 Eu-activated oxynitride phosphor [BSON phosphor] such as ₆ O ₁₂ N ₂ : Eu (wherein M represents an alkaline earth metal element), BaMgAl described in JP-A-2008-274254 ₁₀ _17: Eu, it is also possible to use Mn-activated aluminate phosphor [GBAM phosphor.

As for the particle diameter of the phosphor 4a, the volume-based median diameter D _50v is preferably 0.1 μm or more, more preferably 1 μm or more. Moreover, the thing of 30 micrometers or less is preferable, and the thing of 20 micrometers or less can be used more preferably. Here, the volume-based median diameter D _50v is a volume-based relative when a sample is measured and a particle size distribution (cumulative distribution) is obtained using a particle size distribution measuring apparatus based on a laser diffraction / scattering method. It is defined as the particle size at which the particle amount is 50%. As a measuring method, for example, the phosphor 4a is put in ultrapure water, an ultrasonic disperser (manufactured by Kaijo Co., Ltd.) is used, the frequency is 19 KHz, the ultrasonic intensity is 5 W, and the sample is ultrasonicated for 25 seconds After being dispersed by the above method, the transmittance is adjusted to a range of 88% to 92% using a flow cell, and after confirming that the particles are not aggregated, a laser diffraction particle size distribution analyzer (Horiba LA-300) Examples thereof include a measurement method in a particle size range of 0.1 μm to 600 μm. Further, when the phosphor particles aggregate in the above-described method, a dispersant may be used. For example, phosphor 4a in an aqueous solution containing 0.0003% by weight of Tamol (manufactured by BASF) or the like. And may be measured after being dispersed with ultrasonic waves in the same manner as described above.

As an index indicating the degree of particle size distribution, there is a ratio (D _v / D _n ) between the volume-based average particle size D _v and the number-based average particle size D _n of the phosphor 4a. In the present invention, D _v / D _n is preferably 1.0 or more, more preferably 1.2 or more, and further preferably 1.4 or more. On the other hand, D _v / D _n is preferably 25 or less, more preferably 10 or less, and particularly preferably 5 or less. If D _v / D _n is too large, there will be phosphor particles with greatly different weights, and the phosphor particles will tend to be non-uniformly dispersed in the phosphor layer.

Further, as the phosphor 4a, it is possible to use a phosphor whose surface is previously coated with a third component. The type of the third component used for coating and the coating method are not particularly limited, and any known third component and method may be used.

Examples of the third component include organic acids, inorganic acids, silane treating agents, silicone oil, liquid paraffin, and the like. By using these third components to surface-treat and coat the phosphor 4a, the affinity for the resin 4c, dispersibility, thermal stability, fluorescence coloring property and the like tend to be improved. The surface treatment and the coating amount are usually 0.01 to 10 parts by weight per 100 parts by weight of the phosphor 4a. If the amount is less than 0.01 parts by weight, the affinity, dispersibility, thermal stability, fluorescence coloring property, etc. It is difficult to obtain the improvement effect, and even if the amount exceeds 10 parts by weight, problems such as deterioration of thermal stability, mechanical properties, and fluorescence developability are likely to occur.

The content of the phosphor 4a in the wavelength conversion member 4 depends on the types of the light diffusing element 4b and the resin 4c. For example, when the resin 4c is a polycarbonate resin, the content of the phosphor 4a is usually 0. 1 part by weight or more, preferably 0.5 part by weight or more, more preferably 1 part by weight or more, and usually 50 parts by weight or less, preferably 40 parts by weight or less, more preferably 30 parts by weight or less, still more preferably 20 parts by weight or less. If the content of the phosphor 4a is too small, the wavelength conversion effect of the phosphor tends to be difficult to obtain, and if it is too much, the mechanical properties may be deteriorated.

(Light diffusion element)
In the present embodiment, it is preferable to use an inorganic light diffusing material, an organic light diffusing material, or air bubbles as the light diffusing element 4b.

As the inorganic light diffusing material, for example, inorganic light diffusing materials such as silicon, aluminum, titanium, zirconium, calcium, and barium can be used, and the group consisting of silicon, aluminum, titanium, and zirconium can be used. It is preferable to use an inorganic light diffusing material containing at least one element. As the organic light diffusing material, it is possible to use an acrylic light diffusing material, or an organic light diffusing material containing silicon as an element, or an organic material containing silicon as an element. It is preferable to use a system light diffusing material.

Specific examples of inorganic light diffusing materials include silicon dioxide (silica), white carbon, talc, magnesium oxide, zinc oxide, titanium oxide, aluminum oxide, zirconium oxide, boron oxide, calcium carbonate, barium carbonate, magnesium carbonate, water Examples thereof include aluminum oxide, calcium hydroxide, magnesium hydroxide, barium sulfate, calcium silicate, magnesium silicate, aluminum silicate, sodium aluminosilicate, zinc silicate, glass, mica and the like.

Examples of the organic light diffusing material include styrene (co) polymers, acrylic (co) polymers, siloxane (co) polymers, polyamide (co) polymers, and the like. Some or all of these molecules of the organic diffusing material may or may not be cross-linked. Here, “(co) polymer” means both “polymer” and “copolymer”.

Among the light diffusion elements described above, in order to increase the light diffusion effect with a small amount, it is preferable to select a light diffusion element having a large difference between the refractive index of the base material and the refractive index of the selected light diffusion element. Further, in order not to greatly reduce the luminous efficiency, it is preferable to select a light diffusing element having high transparency.

For example, when the resin 4c is a polycarbonate resin, the light diffusing element 4b includes a crosslinked acrylic (co) polymer particle, a crosslinked particle of a copolymer of an acrylic compound and a styrene compound, a siloxane (co) polymer particle, It is preferable to use hybrid crosslinked particles of an acrylic compound and a compound containing a silicon atom, and it is more preferable to use crosslinked acrylic (co) polymer particles and siloxane (co) polymer particles.

As the crosslinked acrylic (co) polymer particles, polymer particles composed of a non-crosslinkable acrylic monomer and a crosslinkable monomer are more preferable, and polymer particles obtained by crosslinking methyl methacrylate and trimethylolpropane tri (meth) acrylate are more preferable. . As the siloxane-based (co) polymer, polyorganosilsesquioxane particles are more preferable, and polymethylsilsesquioxane particles are more preferable.

In the present invention, polymethylsilsesquioxane particles are particularly preferable in terms of excellent thermal stability.

The dispersion shape of the light diffusing element 4b in the resin 4c may be any of a substantially spherical shape, a plate shape, a needle shape, and an indefinite shape, but is preferably a substantially spherical shape from the viewpoint that there is no anisotropy in light scattering effect. . The average dimension of the light diffusing element 4b is usually 100 μm or less, preferably 30 μm or less, more preferably 10 μm or less, and usually 0.01 μm or more, preferably 0.1 μm or more. More preferably, it is 0.5 μm or more. When the average size of the light diffusing element 4b is out of the above range, the light diffusibility is likely to fluctuate greatly due to a subtle difference in the content of the light diffusing element 4b or a difference in the particle diameter, thereby stabilizing the light diffusibility It may be difficult to control the light diffusibility required in the present invention. As a result, it may become difficult to stably control the wavelength conversion efficiency within a preferable range. Here, the average dimension of the light diffusing element 4b is a 50% average dimension based on volume, and is the value of the median diameter (D50) of the volume standard particle size distribution measured by laser or diffraction scattering method.

Further, the particle size distribution of the light diffusing element 4b may be a monodispersed system or a polydispersed system having several peak tops, and is a single peak top having a narrow particle size distribution. However, it is preferable that the particle size distribution is narrow and the particle size is almost a single particle size (monodispersion or near monodispersion particle size distribution).

As an index indicating the degree of particle size distribution of the light diffusing element 4b, there is a ratio (D _v / D _n ) of the volume-based average particle diameter D _v and the number-based average particle diameter D _n of the light diffusing element 4b. . In the present _invention, it is preferred D v / _{D n} is 1.0 or more. On the other _hand, it is preferred D v / _{D n} is 5 or less. When D _v / D _n is too large, there is a light diffusing element 4 b having a significantly different weight, and the dispersion of the light diffusing element 4 b tends to be non-uniform in the wavelength conversion member 4.

The inorganic light diffusing material, the organic light diffusing material, and the bubbles used as the light diffusing element 4b described above may be used singly or in combination of two or more kinds having different materials and dimensions. Good. When two or more types are used in combination, the refractive index of the light diffusing element 4b is calculated by the volume average of a plurality of light diffusing elements.

The refractive index of the light diffusing element 4b is usually 1.0 or more and usually 1.9 or less. The reason will be described when referring to an evaluation result described later. The light diffusing element 4b preferably has high transparency and excellent light transmittance. For example, the extinction coefficient may be 10 ⁻² or less, preferably 10 ⁻³ or less, and more preferably. 10 ⁻⁴ or less, particularly preferably 10 ⁻⁶ or less. The refractive index of the light diffusing element 4b can be measured by a liquid immersion method (Aerosol Research Vol. 9, No. 1 Spring pp. 44-50 (1994)) of YOSHIYAMA et al. The measurement temperature is 20 ° C., and the measurement wavelength is 450 nm.

Table 1 below shows the refractive indexes of materials generally used as the light diffusing element 4b. In addition, the refractive index of each material in Table 1 is a general reference value, and the refractive index of each material is not necessarily limited to the value in Table 1.

The content of the light diffusing element 4b in the wavelength conversion member 4 depends on the types of the phosphor 4a and the resin 4c. For example, the resin 4c is a polycarbonate resin, and the light diffusing element 4b is polymethylsilsesquioxane particles. In some cases, it is usually 0.1 parts by weight or more, preferably 0.3 parts by weight or more, more preferably 0.5 parts by weight or more, and usually 10.0 parts by weight or less with respect to 100 parts by weight of the polycarbonate resin. The amount is preferably 7.0 parts by weight or less, more preferably 3.0 parts by weight or less. If the content of the light diffusing element 4b is too small, the diffusing effect is insufficient, and the effect of reducing the amount of the phosphor 4a tends to be difficult to obtain. .

The phosphor 4a described above may also diffuse yellow light. However, in the calculation of the volume fraction of the light diffusing element of the present invention, the phosphor 4a is not included as a part of the light diffusing element 4b. .

[Base material]
The base material holds the light diffusing element. Moreover, it is preferable that the light diffusing element is dispersed in the base material. In the present embodiment, it is preferable that the base material holds a phosphor, and the phosphor is dispersed in the base material. As the base material, resin, glass or the like is usually used.

〔resin〕
The resin 4c that disperses and holds the phosphor 4a and the light diffusing element 4b usually has a refractive index of 1.3 or more and 1.7 or less. The reason will be described when referring to an evaluation result described later. In addition, the measuring method of the refractive index of resin 4c is as follows. The measurement temperature is 20 ° C., measured by the prism coupler method. The measurement wavelength is 450 nm.

Table 2 below lists the refractive indices of resins generally used as a base material. In addition, the refractive index of each resin in Table 2 is a general reference value, and the refractive index of each resin is not necessarily limited to the value in Table 2.

As the more specific resin 4c, polycarbonate resin, polyester resin (for example, polyethylene terephthalate resin, polybutylene terephthalate resin), acrylic resin (for example, polymethyl methacrylate resin), epoxy resin, and silicone resin are used. It is preferable. The resin 4c preferably does not absorb light (for example, ultraviolet light, near ultraviolet light, or blue light) emitted from the semiconductor light emitting element or visible light emitted from the wavelength conversion member. Furthermore, it is preferable to have sufficient transparency and durability against blue light emitted from the LED chip 3.

These resins used as the resin 4c described above may be used alone or in combination of two or more. Moreover, the copolymer of these resin may be sufficient and it may use it, laminating | stacking 2 or more types. When two or more types are used in combination, the refractive index of the resin 4c is calculated by the volume average of a plurality of resins.

As the resin 4c, a polycarbonate resin is most preferably used because it is excellent in transparency, heat resistance, mechanical properties, and flame retardancy. Hereinafter, the polycarbonate resin will be described in detail.

The polycarbonate resin used in the present invention is a polymer having a basic structure having a carbonic acid bond represented by the following general chemical formula (1).

In the chemical formula (1), X ¹ is generally a hydrocarbon, but X ¹ into which a hetero atom or a hetero bond is introduced may be used for imparting various properties.

The polycarbonate resin can be classified into an aromatic polycarbonate resin in which the carbon directly bonded to the carbonic acid bond is an aromatic carbon, and an aliphatic polycarbonate resin in which the carbon is an aliphatic carbon, either of which can be used. Of these, aromatic polycarbonate resins are preferred from the viewpoints of heat resistance, mechanical properties, electrical characteristics, and the like.

Although there is no restriction | limiting in the specific kind of polycarbonate resin, For example, the polycarbonate polymer formed by making a dihydroxy compound and a carbonate precursor react is mentioned. At this time, in addition to the dihydroxy compound and the carbonate precursor, a polyhydroxy compound or the like may be reacted. Further, a method of reacting carbon dioxide with a cyclic ether using a carbonate precursor may be used. The polycarbonate polymer may be linear or branched. Further, the polycarbonate polymer may be a homopolymer composed of one type of repeating unit or a copolymer having two or more types of repeating units. At this time, the copolymer can be selected from various copolymerization forms such as a random copolymer and a block copolymer. In general, such a polycarbonate polymer is a thermoplastic resin.

Among monomers used as raw materials for aromatic polycarbonate resins, examples of aromatic dihydroxy compounds include dihydroxy compounds such as 1,2-dihydroxybenzene, 1,3-dihydroxybenzene (ie, resorcinol), 1,4-dihydroxybenzene, and the like. Benzenes; dihydroxybiphenyls such as 2,5-dihydroxybiphenyl, 2,2′-dihydroxybiphenyl, 4,4′-dihydroxybiphenyl; 2,2′-dihydroxy-1,1′-binaphthyl, 1,2-dihydroxy Dihydroxynaphthalenes such as naphthalene, 1,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 2,7-dihydroxynaphthalene; 2 , 2'- Hydroxydiphenyl ether, 3,3′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxy-3,3′-dimethyldiphenyl ether, 1,4-bis (3-hydroxyphenoxy) benzene, 1,3 Dihydroxydiaryl ethers such as bis (4-hydroxyphenoxy) benzene; 2,2-bis (4-hydroxyphenyl) propane (ie bisphenol A), 1,1-bis (4-hydroxyphenyl) propane, 2, 2-bis (3-methyl-4-hydroxyphenyl) propane, 2,2-bis (3-methoxy-4-hydroxyphenyl) propane, 2- (4-hydroxyphenyl) -2- (3-methoxy-4- Hydroxyphenyl) propane, 1,1-bis (3-tert- Til-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (3-cyclohexyl-4-hydroxyphenyl) propane, 2- (4- Hydroxyphenyl) -2- (3-cyclohexyl-4-hydroxyphenyl) propane, α, α'-bis (4-hydroxyphenyl) -1,4-diisopropylbenzene, 1,3-bis [2- (4-hydroxy Phenyl) -2-propyl] benzene, bis (4-hydroxyphenyl) methane, bis (4-hydroxyphenyl) cyclohexylmethane, bis (4-hydroxyphenyl) phenylmethane, bis (4-hydroxyphenyl) (4-propenylphenyl) ) Methane, bis (4-hydroxyphenyl) diphenylmethane, bis (4 Hydroxyphenyl) naphthylmethane, 1-bis (4-hydroxyphenyl) ethane, 2-bis (4-hydroxyphenyl) ethane, 1,1-bis (4-hydroxyphenyl) -1-phenylethane, 1,1-bis (4-hydroxyphenyl) -1-naphthylethane, 1-bis (4-hydroxyphenyl) butane, 2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxyphenyl) pentane, 1,1 -Bis (4-hydroxyphenyl) hexane, 2,2-bis (4-hydroxyphenyl) hexane, 1-bis (4-hydroxyphenyl) octane, 2-bis (4-hydroxyphenyl) octane, 1-bis (4 -Hydroxyphenyl) hexane, 2-bis (4-hydroxyphenyl) hexane, 4,4-bis (4-hydride) Bis (hydroxyaryl) alkanes such as loxyphenyl) heptane, 2,2-bis (4-hydroxyphenyl) nonane, 10-bis (4-hydroxyphenyl) decane, 1-bis (4-hydroxyphenyl) dodecane; 1 -Bis (4-hydroxyphenyl) cyclopentane, 1-bis (4-hydroxyphenyl) cyclohexane, 4-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3-dimethyl Cyclohexane, 1-bis (4-hydroxyphenyl) -3,4-dimethylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3,5-dimethylcyclohexane, 1,1-bis (4-hydroxyphenyl)- 3,3,5-trimethylcyclohexane, 1,1-bis (4-hydroxy -3,5-dimethylphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3-propyl-5-methylcyclohexane, 1,1-bis (4-hydroxyphenyl) -3-tert-butyl-cyclohexane, 1,1-bis (4-hydroxyphenyl) -3-tert-butyl-cyclohexane, 1,1-bis (4-hydroxyphenyl) -3-phenylcyclohexane, 1,1- Bis (hydroxyaryl) cycloalkanes such as bis (4-hydroxyphenyl) -4-phenylcyclohexane; 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (4-hydroxy-3-methylphenyl) ) Cardiostructure-containing bisphenols such as fluorene; 4,4'-dihydroxydiphenyls Dihydroxy diaryl sulfides such as 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfide; 4,4'-dihydroxydiphenyl sulfoxide, 4,4'-dihydroxy-3,3'-dimethyldiphenyl sulfoxide, etc. Dihydroxydiaryl sulfoxides; dihydroxydiaryl sulfones such as 4,4′-dihydroxydiphenylsulfone and 4,4′-dihydroxy-3,3′-dimethyldiphenylsulfone;

Of these, bis (hydroxyaryl) alkanes are preferred, and bis (4-hydroxyphenyl) alkanes are preferred, and 2,2-bis (4-hydroxyphenyl) propane (ie, in terms of impact resistance and heat resistance) Bisphenol A) is preferred.

In addition, 1 type may be used for an aromatic dihydroxy compound, and it may use 2 or more types together by arbitrary combinations and a ratio.

Examples of monomers used as raw materials for aliphatic polycarbonate resins include ethane-1,2-diol, propane-1,2-diol, propane-1,3-diol, 2,2-dimethylpropane-1, 3-diol, 2-methyl-2-propylpropane-1,3-diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, decane-1,10-diol Alkanediols such as cyclopentane-1,2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, 1,4-cyclohexanedimethanol, 4- (2-hydroxyethyl) cyclohexanol, Cycloalkanediols such as 2,2,4,4-tetramethyl-cyclobutane-1,3-diol; Glycols such as xidiethanol (ie ethylene glycol), diethylene glycol, triethylene glycol, propylene glycol, spiroglycol, etc .; 1,2-benzenedimethanol, 1,3-benzenedimethanol, 1,4-benzenedimethanol, 1 , 4-benzenediethanol, 1,3-bis (2-hydroxyethoxy) benzene, 1,4-bis (2-hydroxyethoxy) benzene, 2,3-bis (hydroxymethyl) naphthalene, 1,6-bis (hydroxy Ethoxy) naphthalene, 4,4′-biphenyldimethanol, 4,4′-biphenyldiethanol, 1,4-bis (2-hydroxyethoxy) biphenyl, bisphenol A bis (2-hydroxyethyl) ether, bisphenol S bis (2 -Hydroxyethyl Aralkyldiols such as ether; 1,2-epoxyethane (ie, ethylene oxide), 1,2-epoxypropane (ie, propylene oxide), 1,2-epoxycyclopentane, 1,2-epoxycyclohexane, 1,4 -Cyclic ethers such as epoxycyclohexane, 1-methyl-1,2-epoxycyclohexane, 2,3-epoxynorbornane, 1,3-epoxypropane, etc., may be used alone, or two or more May be used in any combination and ratio.

Among the monomers used as the raw material for the aromatic polycarbonate resin, examples of the carbonate precursor include carbonyl halide and carbonate ester. In addition, 1 type may be used for a carbonate precursor and it may use 2 or more types together by arbitrary combinations and a ratio.

Specific examples of the carbonyl halide include phosgene, haloformates such as bischloroformate of dihydroxy compounds, and monochloroformate of dihydroxy compounds.

Specific examples of carbonate esters include diaryl carbonates such as diphenyl carbonate and ditolyl carbonate; dialkyl carbonates such as dimethyl carbonate and diethyl carbonate; biscarbonate bodies of dihydroxy compounds, monocarbonate bodies of dihydroxy compounds, and cyclic carbonates. And carbonate bodies of dihydroxy compounds such as

The method for producing the polycarbonate resin is not particularly limited, and any method can be adopted. Examples thereof include an interfacial polymerization method, a melt transesterification method, a pyridine method, a ring-opening polymerization method of a cyclic carbonate compound, and a solid phase transesterification method of a prepolymer. Hereinafter, the interfacial polymerization method and the melt transesterification method, which are particularly suitable among these methods, will be specifically described.

(Interfacial polymerization method)
In the interfacial polymerization method, a dihydroxy compound and a carbonate precursor (preferably phosgene) are reacted in the presence of an organic solvent inert to the reaction and an aqueous alkaline solution, usually at a pH of 9 or higher. Polycarbonate resin is obtained by interfacial polymerization in the presence. In the reaction system, a molecular weight adjusting agent (terminal terminator) may be present as necessary, or an antioxidant may be present to prevent the oxidation of the dihydroxy compound.

The dihydroxy compound and the carbonate precursor are as described above. Of the carbonate precursors, phosgene is preferably used, and a method using phosgene is particularly called a phosgene method.

Examples of the organic solvent inert to the reaction include chlorinated hydrocarbons such as dichloromethane, 1,2-dichloroethane, chloroform, monochlorobenzene and dichlorobenzene; aromatic hydrocarbons such as benzene, toluene and xylene. . In addition, 1 type may be used for an organic solvent and it may use 2 or more types together by arbitrary combinations and a ratio.

Examples of the alkali compound contained in the alkaline aqueous solution include alkali metal compounds and alkaline earth metal compounds such as sodium hydroxide, potassium hydroxide, lithium hydroxide, and sodium hydrogen carbonate, among which sodium hydroxide and water Potassium oxide is preferred. In addition, 1 type may be used for an alkali compound and it may use 2 or more types together by arbitrary combinations and a ratio.

The concentration of the alkali compound in the alkaline aqueous solution is not limited, but is usually used at 5 to 10% by weight in order to control the pH in the alkaline aqueous solution of the reaction to 10 to 12. For example, when phosgene is blown, the molar ratio of the bisphenol compound to the alkali compound is usually 1: 1.9 or more in order to control the pH of the aqueous phase to be 10 to 12, preferably 10 to 11. Among these, it is preferable that the ratio is 1: 2.0 or more, usually 1: 3.2 or less, and more preferably 1: 2.5 or less.

Examples of the polymerization catalyst include aliphatic tertiary amines such as trimethylamine, triethylamine, tributylamine, tripropylamine, and trihexylamine; alicyclic rings such as N, N′-dimethylcyclohexylamine and N, N′-diethylcyclohexylamine Tertiary amines; aromatic tertiary amines such as N, N′-dimethylaniline and N, N′-diethylaniline; quaternary ammonium salts such as trimethylbenzylammonium chloride, tetramethylammonium chloride and triethylbenzylammonium chloride; Examples include pyridine, guanine, guanidine salts, and the like. In addition, 1 type may be used for a polymerization catalyst and it may use 2 or more types together by arbitrary combinations and a ratio.

Examples of the molecular weight modifier include aromatic phenols having a monovalent phenolic hydroxyl group; aliphatic alcohols such as methanol and butanol, mercaptans, and phthalimides, among which aromatic phenols are preferred. Specific examples of such aromatic phenols include alkyl groups such as m-methylphenol, p-methylphenol, m-propylphenol, p-propylphenol, p-tert-butylphenol, and p-long chain alkyl-substituted phenol. Substituted phenols: vinyl group-containing phenols such as isopropanyl phenol, epoxy group-containing phenols, carboxyl group-containing phenols such as o-oxine benzoic acid and 2-methyl-6-hydroxyphenylacetic acid. In addition, a molecular weight regulator may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

The amount of the molecular weight modifier used is usually 0.5 mol or more, preferably 1 mol or more, and usually 50 mol or less, preferably 30 mol or less, per 100 mol of the dihydroxy compound. By making the usage-amount of a molecular weight modifier into this range, the thermal stability and hydrolysis resistance of a polycarbonate resin composition can be improved.

In the reaction, the order of mixing the reaction substrate, reaction medium, catalyst, additive and the like is arbitrary as long as a desired polycarbonate resin is obtained, and an appropriate order may be arbitrarily set. For example, when phosgene is used as the carbonate precursor, the molecular weight regulator can be mixed at any time as long as it is between the reaction (phosgenation) of the dihydroxy compound and phosgene and the start of the polymerization reaction. The reaction temperature is usually 0 to 40 ° C., and the reaction time is usually several minutes (for example, 10 minutes) to several hours (for example, 6 hours).

(Melted ester exchange method)
In the melt transesterification method, for example, a transesterification reaction between a carbonic acid diester and a dihydroxy compound is performed.

The dihydroxy compound is as described above. On the other hand, examples of the carbonic acid diester include dialkyl carbonate compounds such as dimethyl carbonate, diethyl carbonate, and di-tert-butyl carbonate; diphenyl carbonate; substituted diphenyl carbonate such as ditolyl carbonate, and the like. Of these, diphenyl carbonate and substituted diphenyl carbonate are preferable, and diphenyl carbonate is particularly preferable. In addition, carbonic acid diester may use 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

The ratio of the dihydroxy compound and the carbonic acid diester is arbitrary as long as the desired polycarbonate resin can be obtained, but it is preferable to use an equimolar amount or more of the carbonic acid diester with respect to 1 mol of the dihydroxy compound. Is more preferable. The upper limit is usually 1.30 mol or less. By setting it as such a range, the amount of terminal hydroxyl groups can be adjusted to a suitable range.

In polycarbonate resins, the amount of terminal hydroxyl groups tends to have a large effect on thermal stability, hydrolysis stability, color tone, and the like. For this reason, you may adjust the amount of terminal hydroxyl groups as needed by a well-known arbitrary method. In the transesterification reaction, a polycarbonate resin in which the terminal hydroxyl group amount is adjusted can be usually obtained by adjusting the mixing ratio of the carbonic acid diester and the aromatic dihydroxy compound, the degree of vacuum during the transesterification reaction, and the like. In addition, the molecular weight of the polycarbonate resin usually obtained can also be adjusted by this operation.

When adjusting the amount of terminal hydroxyl groups by adjusting the mixing ratio of carbonic acid diester and dihydroxy compound, the mixing ratio is as described above. Further, as a more aggressive adjustment method, there may be mentioned a method in which a terminal terminator is mixed separately during the reaction. Examples of the terminal terminator at this time include monohydric phenols, monovalent carboxylic acids, carbonic acid diesters, and the like. In addition, 1 type may be used for a terminal terminator and it may use 2 or more types together by arbitrary combinations and a ratio.

When a polycarbonate resin is produced by the melt transesterification method, a transesterification catalyst is usually used. Any transesterification catalyst can be used. Among them, it is preferable to use, for example, an alkali metal compound and / or an alkaline earth metal compound. In addition, auxiliary compounds such as basic boron compounds, basic phosphorus compounds, basic ammonium compounds, and amine compounds may be used in combination. In addition, 1 type may be used for a transesterification catalyst and it may use 2 or more types together by arbitrary combinations and a ratio.

In the melt transesterification method, the reaction temperature is usually 100 to 320 ° C. The pressure during the reaction is usually a reduced pressure condition of 2 mmHg or less. As a specific operation, a melt polycondensation reaction may be performed under the above-mentioned conditions while removing a by-product such as an aromatic hydroxy compound.

The melt polycondensation reaction can be performed by either a batch method or a continuous method. When performing by a batch type, the order which mixes a reaction substrate, a reaction medium, a catalyst, an additive, etc. is arbitrary as long as a desired aromatic polycarbonate resin is obtained, What is necessary is just to set an appropriate order arbitrarily. However, considering the stability of the polycarbonate resin and the polycarbonate resin composition, the melt polycondensation reaction is preferably carried out continuously.

In the melt transesterification method, a catalyst deactivator may be used as necessary. As the catalyst deactivator, a compound that neutralizes the transesterification catalyst can be arbitrarily used. Examples thereof include sulfur-containing acidic compounds and derivatives thereof. In addition, 1 type may be used for a catalyst deactivator and it may use 2 or more types together by arbitrary combinations and a ratio.

The amount of the catalyst deactivator used is usually 0.5 equivalents or more, preferably 1 equivalent or more, and usually 10 equivalents or less, relative to the alkali metal or alkaline earth metal contained in the transesterification catalyst. Preferably it is 5 equivalents or less. Furthermore, it is 1 ppm or more normally with respect to aromatic polycarbonate resin, and is 100 ppm or less normally, Preferably it is 20 ppm or less.

The molecular weight of the polycarbonate resin is arbitrary and may be appropriately selected and determined. The viscosity average molecular weight [Mv] converted from the solution viscosity is usually 10,000 or more, preferably 16,000 or more, more preferably 18, 000 or more, and usually 40,000 or less, preferably 30,000 or less. By setting the viscosity average molecular weight to be equal to or higher than the lower limit of the above range, the mechanical strength of the polycarbonate resin composition of the present invention can be further improved, which is more preferable when used for applications requiring high mechanical strength. On the other hand, by setting the viscosity average molecular weight to be equal to or lower than the upper limit of the above range, the polycarbonate resin composition of the present invention can be suppressed and improved in fluidity, and the molding processability can be improved and the molding process can be easily performed. Two or more types of polycarbonate resins having different viscosity average molecular weights may be mixed and used, and in this case, a polycarbonate resin having a viscosity average molecular weight outside the above-mentioned preferred range may be mixed.

The viscosity average molecular weight [Mv] is obtained by using methylene chloride as a solvent and obtaining an intrinsic viscosity [η] (unit: dl / g) at a temperature of 20 ° C. using an Ubbelohde viscometer. , Η = 1.23 × 10 ⁻⁴ Mv ^0.83 . The intrinsic viscosity [η] is a value calculated by the following formula (1) by measuring the specific viscosity [η _sp ] at each solution concentration [C] (g / dl).

The terminal hydroxyl group concentration of the polycarbonate resin is arbitrary and may be appropriately selected and determined, but is usually 1,000 ppm or less, preferably 800 ppm or less, more preferably 600 ppm or less. Thereby, the residence heat stability and color tone of the polycarbonate resin composition of the present invention can be further improved. Moreover, the minimum is 10 ppm or more normally, Preferably it is 30 ppm or more, More preferably, it is 40 ppm or more. Thereby, the fall of molecular weight can be suppressed and the mechanical characteristic of the polycarbonate resin composition of this invention can be improved more. The unit of the terminal hydroxyl group concentration is the weight of the terminal hydroxyl group expressed in ppm relative to the weight of the polycarbonate resin. The measuring method is a colorimetric determination by the titanium tetrachloride / acetic acid method (the method described in Macromol. Chem. 88 215 (1965)).

The polycarbonate resin may be used alone or in combination of two or more in any combination and ratio.

The polycarbonate resin is a polycarbonate resin alone (the polycarbonate resin alone is not limited to an embodiment containing only one type of polycarbonate resin, and is used in a sense including an embodiment containing a plurality of types of polycarbonate resins having different monomer compositions and molecular weights, for example. .), Or an alloy (mixture) of a polycarbonate resin and another thermoplastic resin may be used in combination. Further, for example, for the purpose of further improving flame retardancy and impact resistance, a polycarbonate resin is copolymerized with an oligomer or polymer having a siloxane structure; for the purpose of further improving thermal oxidation stability and flame retardancy A monomer, oligomer or polymer having a copolymer; a monomer, oligomer or polymer having a dihydroxyanthraquinone structure for the purpose of improving thermal oxidation stability; Copolymers with oligomers or polymers having an olefin-based structure; for the purpose of improving chemical resistance, they may be configured as copolymers mainly composed of polycarbonate resins, such as copolymers with polyester resin oligomers or polymers. . When used in combination with other thermoplastic resins, the proportion of the polycarbonate resin in the resin component is preferably 50% by weight or more, more preferably 60% by weight, and further preferably 70% by weight or more. preferable.

Further, in order to improve the appearance of the molded product and the fluidity, the polycarbonate resin may contain a polycarbonate oligomer. The viscosity average molecular weight [Mv] of this polycarbonate oligomer is usually 1,500 or more, preferably 2,000 or more, and usually 9,500 or less, preferably 9,000 or less. Furthermore, the polycarbonate ligomer contained is preferably 30% by weight or less of the polycarbonate resin (including the polycarbonate oligomer).

Furthermore, the polycarbonate resin may be not only a virgin raw material but also a polycarbonate resin regenerated from a used product (so-called material-recycled polycarbonate resin). Examples of the used products include: optical recording media such as optical disks; light guide plates; vehicle window glass, vehicle headlamp lenses, windshields and other vehicle transparent members; water bottles and other containers; eyeglass lenses; Examples include architectural members such as glass windows and corrugated sheets. Also, non-conforming products, pulverized products obtained from sprues, runners, etc., or pellets obtained by melting them can be used.

However, the recycled polycarbonate resin is preferably 80% by weight or less, more preferably 50% by weight or less, among the polycarbonate resins contained in the polycarbonate resin composition of the present invention. Recycled polycarbonate resin is likely to have undergone deterioration such as heat deterioration and aging deterioration, so when such polycarbonate resin is used more than the above range, hue and mechanical properties can be reduced. It is because there is sex.

In the resin 4c described above, various known additives can be added as necessary within the range not impairing the characteristics of the present invention. For example, heat stabilizer, antioxidant, mold release agent, flame retardant, flame retardant aid, UV absorber, lubricant, light stabilizer, plasticizer, antistatic agent, thermal conductivity improver, conductivity improver, Coloring agents, impact resistance improving agents, antibacterial agents, chemical resistance improving agents, reinforcing agents, laser marking improving agents, refractive index adjusting agents and the like can be mentioned. The specific kind and amount of these additives can be selected from known suitable ones for the resin 4c.

Here, preferable additives to be blended in the polycarbonate resin will be exemplified.

Examples of the heat stabilizer include phosphorus compounds. Any known phosphorous compound can be used. Specific examples include phosphorus oxo acids such as phosphoric acid, phosphonic acid, phosphorous acid, phosphinic acid, and polyphosphoric acid; acidic pyrophosphate metal salts such as acidic sodium pyrophosphate, acidic potassium pyrophosphate, and acidic calcium pyrophosphate; phosphoric acid Examples thereof include phosphates of Group 1 or Group 10 metals such as potassium, sodium phosphate, cesium phosphate, and zinc phosphate; organic phosphate compounds, organic phosphite compounds, and organic phosphonite compounds.

Among them, triphenyl phosphite, tris (monononylphenyl) phosphite, tris (monononyl / dinonyl phenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, monooctyl diphenyl phosphite, Dioctyl monophenyl phosphite, monodecyl diphenyl phosphite, didecyl monophenyl phosphite, tridecyl phosphite, trilauryl phosphite, tristearyl phosphite, 2,2-methylenebis (4,6-di-tert-butylphenyl) ) Organic phosphites such as octyl phosphite are preferred.

The content of the heat stabilizer is usually 0.001 parts by weight or more, preferably 0.001 parts by weight or more, more preferably 0.01 parts by weight or more with respect to 100 parts by weight of the polycarbonate resin. It is not more than parts by weight, preferably not more than 0.5 parts by weight, more preferably not more than 0.3 parts by weight, still more preferably not more than 0.1 parts by weight. If the amount of the heat stabilizer is too small, it is difficult to obtain the effect of improving the heat stability.

Examples of the antioxidant include hindered phenol antioxidants. Specific examples thereof include pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl). ) Propionate, thiodiethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N′-hexane-1,6-diylbis [3- (3,5-di-) tert-butyl-4-hydroxyphenylpropionamide), 2,4-dimethyl-6- (1-methylpentadecyl) phenol, diethyl [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl ] Methyl] phosphoate, 3,3 ′, 3 ″, 5,5 ′, 5 ″ -hexa-tert-butyl-a, a ′, a ''-(Mesitylene-2,4,6-triyl) tri-p-cresol, 4,6-bis (octylthiomethyl) -o-cresol, ethylenebis (oxyethylene) bis [3- (5-tert- Butyl-4-hydroxy-m-tolyl) propionate], hexamethylenebis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-tris (3,5- Di-tert-butyl-4-hydroxybenzyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 2,6-di-tert-butyl-4- (4 And 6-bis (octylthio) -1,3,5-triazin-2-ylamino) phenol.

Among them, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate preferable.

The content of the antioxidant is usually 0.001 part by weight or more, preferably 0.01 part by weight or more, and usually 1 part by weight or less, preferably 0.5 part by weight with respect to 100 parts by weight of the polycarbonate resin. Part or less, more preferably 0.3 part by weight or less. When the content of the antioxidant is less than or equal to the lower limit of the range, the effect as an antioxidant may be insufficient, and when the content of the antioxidant exceeds the upper limit of the range, There is a possibility that the effect reaches its peak and is not economical.

Examples of the release agent include aliphatic carboxylic acids, esters of aliphatic carboxylic acids and alcohols, aliphatic hydrocarbon compounds having a number average molecular weight of 200 to 15,000, and polysiloxane silicone oils.

Examples of the aliphatic carboxylic acid include saturated or unsaturated aliphatic monovalent, divalent, or trivalent carboxylic acids. Here, the aliphatic carboxylic acid includes alicyclic carboxylic acid. Among these, preferred aliphatic carboxylic acids are monovalent or divalent carboxylic acids having 6 to 36 carbon atoms, and aliphatic saturated monovalent carboxylic acids having 6 to 36 carbon atoms are more preferred. Specific examples of such aliphatic carboxylic acids include palmitic acid, stearic acid, caproic acid, capric acid, lauric acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, mellicic acid, tetrariacontanoic acid, montanic acid, adipine Examples include acids and azelaic acid.

As the aliphatic carboxylic acid in the ester of an aliphatic carboxylic acid and an alcohol, for example, the same one as the aliphatic carboxylic acid can be used. On the other hand, examples of the alcohol include saturated or unsaturated monohydric or polyhydric alcohols. These alcohols may have a substituent such as a fluorine atom or an aryl group. Among these, a monovalent or polyvalent saturated alcohol having 30 or less carbon atoms is preferable, and an aliphatic or alicyclic saturated monohydric alcohol or aliphatic saturated polyhydric alcohol having 30 or less carbon atoms is more preferable.

Specific examples of such alcohols include octanol, decanol, dodecanol, stearyl alcohol, behenyl alcohol, ethylene glycol, diethylene glycol, glycerin, pentaerythritol, 2,2-dihydroxyperfluoropropanol, neopentylene glycol, ditrimethylolpropane, dipentaerythritol and the like. Is mentioned.

Specific examples of esters of aliphatic carboxylic acids and alcohols include beeswax (a mixture based on myricyl palmitate), stearyl stearate, behenyl behenate, stearyl behenate, glycerin monopalmitate, glycerin monostearate Examples thereof include rate, glycerol distearate, glycerol tristearate, pentaerythritol monopalmitate, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, pentaerythritol tetrastearate and the like.

Examples of the aliphatic hydrocarbon compound having a number average molecular weight of 200 to 15,000 include liquid paraffin, paraffin wax, microwax, polyethylene wax, Fischer-Tropsch wax, and α-olefin oligomer having 3 to 12 carbon atoms. . Here, the aliphatic hydrocarbon includes alicyclic hydrocarbons.

Among these, paraffin wax, polyethylene wax, or a partial oxide of polyethylene wax is preferable, and paraffin wax and polyethylene wax are more preferable.

The number average molecular weight of the aliphatic hydrocarbon is preferably 5,000 or less.

Examples of the polysiloxane silicone oil include dimethyl silicone oil, phenylmethyl silicone oil, diphenyl silicone oil, and fluorinated alkyl silicone.

The content of the release agent is usually 0.001 part by weight or more, preferably 0.01 part by weight or more, and usually 5 parts by weight or less, preferably 3 parts by weight or less, relative to 100 parts by weight of the polycarbonate resin. More preferably, it is 1 part by weight or less, and still more preferably 0.5 part by weight or less. When the content of the release agent is not more than the lower limit of the above range, the effect of releasability may not be sufficient, and when the content of the release agent exceeds the upper limit of the above range, hydrolysis resistance And mold contamination during injection molding may occur.

Examples of the flame retardant include halogen-based, phosphorus-based, organic acid metal salt-based, and silicone-based flame retardants, and examples of the flame retardant aid include fluororesin-based flame retardant aids. A flame retardant and a flame retardant aid can be used in combination, or a plurality of flame retardants can be used in combination. Among these, phosphorus flame retardants, organic acid metal salt flame retardants, and fluororesin flame retardant aids are preferred.

Examples of phosphorus-based flame retardants include aromatic phosphate esters and phosphazene compounds. As the organic acid metal salt flame retardant, an organic sulfonic acid metal salt is preferable, and a fluorine-containing organic sulfonic acid metal salt is particularly preferable. Specific examples thereof include potassium perfluorobutane sulfonate. As the fluorine-based flame retardant aid, a fluoroolefin resin is preferable, and a tetrafluoroethylene resin having a fibril structure can be exemplified. The fluorine-based flame retardant aid may be in a powder form, a dispersion form, a powder form in which a fluororesin is coated with another resin, or any form.

The blending ratio of these flame retardants and flame retardant aids may be blended in the amount necessary to achieve the desired flame retardant level, but is usually in the case of phosphorus flame retardants relative to 100 parts by weight of polycarbonate. It is preferably blended in the range of 1 to 20 parts by weight, in the case of organic acid metal salts in the range of 0.01 to 1 part by weight, and in the case of fluororesin-based flame retardant aids in the range of 0.01 to 1 part by weight. . Within the above range, one or more flame retardants and flame retardant aids can be used. If the amount is less than this range, it is difficult to improve the flame retardancy. The flame retardant level can be determined by, for example, a combustion test typified by UL94.

Examples of ultraviolet absorbers include inorganic ultraviolet absorbers such as cerium oxide and zinc oxide; organics such as benzotriazole compounds, benzophenone compounds, salicylate compounds, cyanoacrylate compounds, triazine compounds, oxanilide compounds, malonic ester compounds, and hindered amine compounds. Examples include ultraviolet absorbers. Of these, organic ultraviolet absorbers are preferred, and benzotriazole compounds are more preferred. By selecting an organic ultraviolet absorber, the polycarbonate resin composition of the present invention tends to have good transparency and mechanical properties.

Specific examples of the benzotriazole compound include, for example, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- [2′-hydroxy-3 ′, 5′-bis (α, α-dimethylbenzyl). ) Phenyl] -benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-tert-butyl-phenyl) -benzotriazole, 2- (2′-hydroxy-3′-tert-butyl-5 ′) -Methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-butyl-phenyl) -5-chlorobenzotriazole), 2- (2'-hydroxy-3 ', 5'-di-tert-amyl) -benzotriazole, 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2N-benzotriazol-2-yl) phenol], among others, 2- (2 ′ -Hydroxy-5′-tert-octylphenyl) benzotriazole, 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2N-benzotriazol-2-yl) phenol In particular, 2- (2′-hydroxy-5′-tert-octylphenyl) benzotriazole is preferable.

Specific examples of such benzotriazole compounds include “Seesorb 701”, “Seesorb 702”, “Seesorb 703”, “Seesorb 704”, and “Seesorb 705” manufactured by Sipro Kasei Co., Ltd. (trade names, the same applies hereinafter). , “Seasorb 709”, “Biosorb 520”, “Biosorb 580”, “Biosorb 582”, “Biosorb 583”, manufactured by Kyodo Yakuhin Co., Ltd. “UV5411”, “LA-32”, “LA-38”, “LA-36”, “LA-34”, “LA-31” manufactured by Adeka Corporation, “Tinuvin P”, “Cinuvin” manufactured by Ciba Specialty Chemicals 234 "," Tinubin 326 "," Tinubin 327 "," Tinubin 28 ", and the like.

The preferable content of the ultraviolet absorber is 0.01 parts by weight or more, more preferably 0.1 parts by weight or more, and 5 parts by weight or less, preferably 3 parts by weight or less with respect to 100 parts by weight of the polycarbonate resin. More preferably, it is 1 part by weight or less, and still more preferably 0.5 part by weight or less. If the content of the UV absorber is below the lower limit of the above range, the effect of improving the weather resistance may be insufficient, and if the content of the UV absorber exceeds the upper limit of the above range, the mold Debogit etc. may occur and cause mold contamination. In addition, 1 type may contain the ultraviolet absorber and 2 or more types may contain it by arbitrary combinations and a ratio.

[Method for producing resin composition constituting wavelength conversion member 4]
The manufacturing method of the resin composition which comprises the wavelength conversion member 4, and the processing method of the wavelength conversion member 4 are not specifically limited, What is necessary is just to use a well-known method as a processing method of resin 4c. For example, the general manufacturing method of the resin composition when the resin 4c is a polycarbonate resin is as follows.

The phosphor 4a, the light diffusing element 4b, and other components blended as necessary are added to the polycarbonate resin and mixed with various mixers such as a tumbler mixer and a Henschel mixer. Mixing may be performed by mixing all raw materials at once, or by dividing several raw materials and mixing them. Thereafter, it is melt-kneaded with a Banbury mixer, roll, Brabender, single-screw kneading extruder, twin-screw kneading extruder, kneader or the like to obtain resin composition pellets.

Using the obtained resin composition pellets, required by any molding method such as sheet / film extrusion molding, profile extrusion molding, vacuum molding, injection molding, blow molding, injection blow molding, rotational molding, foam molding, etc. The shaped wavelength conversion member 4 is formed. Among these, it is preferable to adopt an injection molding method. Furthermore, if necessary, the molded body can be further processed by welding, bonding, cutting, and the like. When the light diffusing element 4b is a bubble, the bubble may be formed in the member by a method such as blending of a blowing agent, nitrogen gas injection, supercritical gas injection, or the like.

In the case where the resin 4c is a polycarbonate resin and the light diffusing element 4b is other than bubbles, the preferable conditions are illustrated in more detail.

The polycarbonate resin, the phosphor 4a, the light diffusing element 4b, and other additives are mixed with a tumbler mixer and then melt-kneaded using a single screw or twin screw extruder. As a melt-kneading condition, a screw composed mainly of a forward-flight flight screw element is used as a screw so as not to apply excessive pruning force. The frequent use of a screw element that strongly applies a cutting force, such as a reverse feed flight screw or a kneading screw element, is undesirable because it causes discoloration of the resin. In addition, when the phosphor 4a is hard, it is preferable to use a material that has been subjected to an abrasion-resistant treatment that is difficult to scrape as the material of the screw and cylinder.

The kneading temperature is preferably in the range of 230 to 340 ° C. If the measured resin temperature exceeds 340 ° C., discoloration tends to occur, which is not preferable. If the resin temperature is less than 230 ° C., the melt viscosity of the polycarbonate resin is too high, and the mechanical load on the extruder increases. A particularly preferable kneading temperature is in the range of 240 to 300 ° C.

The screw rotation speed and discharge amount may be appropriately selected in view of the production speed, the load on the extruder, and the state of the resin pellets. Moreover, it is preferable to install one or more vent structures in the extruder for releasing air entrained with the raw material and gas generated by heating out of the extruder system.

What is necessary is just to shape | mold and process into a desired shape by arbitrary processing methods using the polycarbonate resin composition pellet obtained by the above.

The semiconductor light emitting device 1 of the present embodiment having the configuration as described above can be used as general illumination. In such a case, the light emitted from the semiconductor light emitting device 1 (specifically, white light that is a combined light of blue light and yellow light) has a deviation duv of −0.0200 to 0.0200 from the black body radiation locus. The color temperature is preferably in the range of 1,600K to 7,000K.

Further, the semiconductor light emitting device 1 of the present embodiment having the above-described configuration can be used as a backlight in addition to general illumination. When used as an LED light source for a backlight of a display, light emitted from the semiconductor light emitting device 1 (specifically, white light which is a combined light of blue light and yellow light) usually has a color temperature of 5,000K to Within the range of 20,000K.

(Evaluation by simulation)
Next, for the semiconductor light emitting device 1 in this embodiment, the materials and characteristics of the YAG phosphor 4a, the light diffusing element 4b, and the resin 4c are changed, and the light emission efficiency of each semiconductor light emitting device is calculated by simulation, and the calculation is performed. The results (simulation results) were evaluated. As more specific conditions, the characteristics (refractive index, extinction coefficient, quantum efficiency) of the phosphor 4a are known publications “Zongyuan Liu” and three others, “YAG for white light emitting diode package: “Measurement and numerical studies of optical properties of YAG: Ce phosphor for white light-emitting diode packaging”, APPLIED OPTICS, January 10, 2010, No. 1 49, No. 2, p. 247-257 ”. Further, the visible light reflectance of the wiring board 2 was 90%, the extinction coefficient of the light diffusing element 4b was 10 ⁻⁶ or less, and the extinction coefficient of the light absorption coefficient of the resin 4c was 10 ⁻⁶ or less. Furthermore, the target chromaticity of the semiconductor light emitting device 1 was set to x = 0.30 and y = 0.31. The average particle size and particle size distribution of the light diffusing element 4b and the average particle size and particle size distribution of the phosphor 4a are assumed to be various, and LightTools (registered as lighting design analysis software of ORA (currently Synopsis)) is registered. (Trademark) was used for the simulation by the ray tracing method. The simulation results will be described in detail with reference to Tables 3 to 8 and FIGS. 5 and 6, and favorable conditions of the wavelength conversion member 4 will be described. In Tables 3 to 8, the value of “volume fraction of light diffusing element” is expressed by rounding off the third decimal place to the second decimal place, but “refractive index difference × thickness × volume fraction”. In calculating the value of “,” the volume fraction of the light diffusing element is calculated by using the numerical value up to the fourth decimal place, so the value of “refractive index difference × thickness × volume fraction” There may be a gap between the notation and the actual calculated value.

Assuming the case where silicon dioxide is used for the light diffusing element 4b and polycarbonate resin is used for the resin 4c as the first sample group, when the amount of silicon dioxide used as the light diffusing element 4b (volume fraction) is changed, The light emission efficiency (lm / W) of each semiconductor light emitting device was calculated by simulation. As a specific condition, the wavelength conversion member 4 was composed of the phosphor 4a and the polycarbonate resin as the resin 4c without including the silicon dioxide as the light diffusion element 4b in the wavelength conversion member 4 in the sample 1-1. The wavelength converting members 4 of Samples 1-2 to 1-20 contain silicon dioxide as the light diffusing element 4b, and the wavelength converting member 4 is made of the phosphor 4a, the light diffusing element 4b, and the polycarbonate resin as the resin 4c. The content of the light diffusing element 4b was increased as the sample number increased, and the volume fraction (vol%) of the light diffusing element 4b was increased.

In the simulation of the first sample group, silicon dioxide was assumed for the light diffusing element 4b and polycarbonate resin was assumed for the resin 4c. Therefore, the refractive index at 450 nm at a measurement temperature of 20 ° C. was 1.45 for the light diffusing element 4b and the resin 4c. Was 1.58. The density of the light diffusing element 4b was 2.20 g / cm ³ and the density of the resin 4c was 1.20 g / cm ³ . Furthermore, the thickness of the wavelength conversion member 4 itself (that is, the thickness of the resin 4c) was set to 1.00 mm.

Table 3 below shows “volume fraction of light diffusing element 4b (vol%)”, “difference of refractive index × thickness of wavelength conversion member 4 itself × volume of light diffusing element 4b” in each sample (semiconductor light emitting device 1). Rate "," use concentration of phosphor 4a (wt%) "," decrease rate of use concentration of phosphor 4a (%) "," emission efficiency (lm / W) ", and" emission efficiency maintenance rate (%) ) ". Here, the “decrease rate (%) of the use concentration of the phosphor 4a” is the difference between the use concentration of the phosphor 4a in the sample 1-1 and the use concentration of the phosphor 4a in each of the other samples. Divided by the working concentration of phosphor 4a at -1, and the divided value is multiplied by 100. The “luminance efficiency maintenance ratio (%)” is a numerical value obtained by dividing the luminous efficiency of each of the other samples by the luminous efficiency of the sample 1-1 with the luminous efficiency of the sample 1-1 as a reference (100%). 100 times.

As shown in Table 3, in the first sample group, the refractive index difference between the light diffusing element and the base material × the thickness of the light conversion member × the volume fraction of the light diffusing element is 0.743, and the phosphor 4a The concentration used could be reduced by 85.8%, and the luminous efficiency maintenance rate was 91.5%.

In addition, when the difference in refractive index between the light diffusing element and the base material × the thickness of the light conversion member × the volume fraction of the light diffusing element is 2.463, the usage concentration of the phosphor 4a is reduced by 91.1%. In this case, the maintenance ratio of the luminous efficiency was 75.7%. Even in this case, it is possible to secure a value (70% or more) of the luminous efficiency maintenance rate that can generally obtain good characteristics.

Furthermore, when the value of the difference in refractive index between the light diffusing element and the base material × the thickness of the light conversion member × the volume fraction of the light diffusing element exceeds 3.467, the reduction rate of the use concentration of the phosphor 4a is 90.7%. However, it has been found that the maintenance ratio of the luminous efficiency is less than 70%.

That is, in the first sample group, the concentration of the phosphor 4a is adjusted by setting the difference in refractive index between the light diffusing element and the base material × the thickness of the light conversion member × the volume fraction of the light diffusing element within an appropriate range. It was found that the light emission efficiency can be reduced and the luminous efficiency can be sufficiently maintained.

Assuming a case where silicon dioxide is used for the light diffusing element 4b and a silicone resin is used for the resin 4c as the second sample group, when the amount of silicon dioxide used as the light diffusing element 4b (volume fraction) is changed, The light emission efficiency (lm / W) of each semiconductor light emitting device was calculated by simulation. As specific conditions, the wavelength conversion member 4 was composed of the phosphor 4a and the silicone resin as the resin 4c without including the silicon dioxide as the light diffusing element 4b in the wavelength conversion member 4 in the sample 2-1. Then, the wavelength conversion members 4 of Sample 2-2 to Sample 2-19 contain silicon dioxide as the light diffusion element 4b, and the wavelength conversion member 4 is converted from the phosphor 4a, the light diffusion element 4b, and the silicone resin as the resin 4c. The content of the light diffusing element 4b was increased as the sample number increased, and the volume fraction (vol%) of the light diffusing element 4b was increased.

In the simulation of the second sample group, silicon dioxide was assumed for the light diffusing element 4b and silicone resin was assumed for the resin 4c. Therefore, the refractive index at 450 nm at a measurement temperature of 20 ° C. was 1.45 for the light diffusing element 4b and the resin 4c. Was 1.40. Further, the density of the light diffusing elements 4b 2.20 g / cm ^3, the density of the resin 4c was 1.00 g / cm ^3. Furthermore, the thickness of the wavelength conversion member 4 itself (that is, the thickness of the resin 4c) was set to 1.00 mm.

Table 4 below shows “volume fraction of light diffusing element 4b (vol%)”, “difference in refractive index × thickness of wavelength conversion member 4 itself × volume of light diffusing element 4b” in each sample (semiconductor light emitting device 1). Rate "," use concentration of phosphor 4a (wt%) "," decrease rate of use concentration of phosphor 4a (%) "," emission efficiency (lm / W) ", and" emission efficiency maintenance rate (%) ) ". The “decrease rate (%) of use concentration of phosphor 4a” and “maintenance rate (%) of luminous efficiency” are the same as those defined in Table 3.

As shown in Table 4, in the second sample group, the difference in refractive index between the light diffusing element and the base material × the thickness of the light conversion member × the volume fraction of the light diffusing element is 0.240, and the phosphor 4a The concentration used could be reduced by 55.0%, and the maintenance rate of the luminous efficiency was 95.2%.

Further, when the value of the refractive index difference between the light diffusing element and the base material × the thickness of the light conversion member × the volume fraction of the light diffusing element is 1.563, the usage concentration of the phosphor 4a is reduced by 82.1%. In this case, the maintenance ratio of the luminous efficiency was 90.4%. Even in this case, it is possible to secure a value (70% or more) of the luminous efficiency maintenance rate that can generally obtain good characteristics.

That is, also in the second sample group, by setting the value of the refractive index difference between the light diffusing element and the base material × the thickness of the light conversion member × the volume fraction of the light diffusing element to an appropriate range, Although there was no effect of maintaining the luminous efficiency, it was found that the use concentration of the phosphor 4a can be reduced and the luminous efficiency can be sufficiently maintained.

Assuming the case where aluminum oxide is used for the light diffusing element 4b and polycarbonate resin is used for the resin 4c as the third sample group, when the amount of aluminum oxide used as the light diffusing element 4b (volume fraction) is changed, The light emission efficiency (lm / W) of each semiconductor light emitting device was calculated by simulation. As specific conditions, the wavelength conversion member 4 was made of the phosphor 4a and the polycarbonate resin, which is the resin 4c, without containing the aluminum oxide as the light diffusing element 4b in the wavelength conversion member 4 in the sample 3-1. The wavelength converting members 4 of Samples 3-2 to 3-20 contain aluminum oxide as the light diffusing element 4b, and the wavelength converting member 4 is made of the phosphor 4a, the light diffusing element 4b, and the polycarbonate resin as the resin 4c. The content of the light diffusing element 4b was increased as the sample number increased, and the volume fraction (vol%) of the light diffusing element 4b was increased.

In the simulation of the third sample group, it was assumed that the light diffusing element 4b was made of aluminum oxide and the resin 4c was made of polycarbonate resin. Therefore, the light diffusing element 4b was 1.75 and the resin 4c as a refractive index at 450 nm at a measurement temperature of 20 ° C. Was 1.58. Further, the density of the light diffusing elements 4b 4.00 g / cm ^3, and the density of the resin 4c and 1.20 g / cm ^3. Furthermore, the thickness of the wavelength conversion member 4 itself (that is, the thickness of the resin 4c) was set to 1.00 mm.

In Table 5 below, “volume fraction of light diffusing element 4b (vol%)”, “difference of refractive index × thickness of wavelength converting member 4 itself × volume of light diffusing element 4b” in each sample (semiconductor light emitting device 1). Rate "," use concentration of phosphor 4a (wt%) "," decrease rate of use concentration of phosphor 4a (%) "," emission efficiency (lm / W) ", and" emission efficiency maintenance rate (%) ) ". The “decrease rate (%) of use concentration of phosphor 4a” and “maintenance rate (%) of luminous efficiency” are the same as those defined in Table 3.

As shown in Table 5, in the third sample group, the difference in refractive index between the light diffusing element and the base material × the thickness of the light conversion member × the volume fraction of the light diffusing element is 0.548, and the phosphor 4a The working concentration could be reduced by 87.2%, and the luminous efficiency maintenance rate was 90.1%.

In addition, when the value of the difference in refractive index between the light diffusing element and the base material × the thickness of the light conversion member × the volume fraction of the light diffusing element is 1.186, the use concentration of the phosphor 4a is reduced by 91.2%. In this case, the maintenance ratio of the luminous efficiency was 84.1%. Even in this case, it is possible to secure a value (70% or more) of the luminous efficiency maintenance rate that can generally obtain good characteristics.

Further, when the value of the difference in refractive index between the light diffusing element and the base material × the thickness of the light conversion member × the volume fraction of the light diffusing element exceeds 1.937, the reduction rate of the use concentration of the phosphor 4a is 91.7%. However, it has been found that the maintenance ratio of the luminous efficiency is less than 70%.

That is, also in the third sample group, the value of the difference in refractive index between the light diffusing element and the base material × the thickness of the light conversion member × the volume fraction of the light diffusing element is set to an appropriate range, thereby being the same as in the first sample group. In addition, it was found that the use concentration of the phosphor 4a can be reduced and the luminous efficiency can be sufficiently maintained.

Assuming a case where aluminum oxide is used for the light diffusing element 4b and silicone resin is used for the resin 4c as the fourth sample group, the amount of use (volume fraction) of aluminum oxide that is the light diffusing element 4b is changed. The light emission efficiency (lm / W) of each semiconductor light emitting device was calculated by simulation. As a specific condition, the wavelength conversion member 4 was composed of the phosphor 4a and the silicone resin as the resin 4c without including the aluminum oxide as the light diffusion element 4b in the wavelength conversion member 4 in the sample 4-1. Then, the wavelength conversion members 4 of Sample 4-2 to Sample 4-19 contain aluminum oxide as the light diffusion element 4b, and the wavelength conversion member 4 is formed from the phosphor 4a, the light diffusion element 4b, and the silicone resin as the resin 4c. The content of the light diffusing element 4b was increased as the sample number increased, and the volume fraction (vol%) of the light diffusing element 4b was increased.

In the simulation of the fourth sample group, since the light diffusing element 4b is assumed to be aluminum oxide and the resin 4c is assumed to be a silicone resin, the light diffusing element 4b has a refractive index at 450 nm at a measurement temperature of 20 ° C. Was 1.40. Further, the density of the light diffusing elements 4b 4.00 g / cm ^3, the density of the resin 4c was 1.00 g / cm ^3. Furthermore, the thickness of the wavelength conversion member 4 itself (that is, the thickness of the resin 4c) was set to 1.00 mm.

In Table 6 below, “volume fraction of light diffusing element 4b (vol%)”, “difference in refractive index × thickness of wavelength converting member 4 itself × volume of light diffusing element 4b” in each sample (semiconductor light emitting device 1). Rate "," use concentration of phosphor 4a (wt%) "," decrease rate of use concentration of phosphor 4a (%) "," emission efficiency (lm / W) ", and" emission efficiency maintenance rate (%) ) ". The “decrease rate (%) of use concentration of phosphor 4a” and “maintenance rate (%) of luminous efficiency” are the same as those defined in Table 3.

As shown in Table 6, in the fourth sample group, the difference in refractive index between the light diffusing element and the base material × the thickness of the light conversion member × the volume fraction of the light diffusing element is 0.178, and the phosphor 4a The concentration used could be reduced to 80.4% and the luminous efficiency maintenance rate was 91.1%.

In addition, when the value of the refractive index difference between the light diffusing element and the base material × the thickness of the light conversion member × the volume fraction of the light diffusing element is 0.946, the concentration of the phosphor 4a used is reduced by 93.0%. In this case, the maintenance ratio of the luminous efficiency was 71.7%. Even in this case, it is possible to secure a value (70% or more) of the luminous efficiency maintenance rate that can generally obtain good characteristics.

Further, when the value of the difference in refractive index between the light diffusing element and the base material × the thickness of the light converting member × the volume fraction of the light diffusing element exceeds 0.946, the reduction ratio of the concentration of the phosphor 4a used is 93.0%. However, it has been found that the maintenance ratio of the luminous efficiency is less than 70%.

That is, also in the fourth sample group, the value of the refractive index difference between the light diffusing element and the base material × the thickness of the light conversion member × the volume fraction of the light diffusing element is set to an appropriate range, thereby being the same as in the first sample group. In addition, it was found that the use concentration of the phosphor 4a can be reduced and the luminous efficiency can be sufficiently maintained.

Assuming the case where bubbles are used for the light diffusion element 4b and polycarbonate resin is used for the resin 4c as the fifth sample group, each semiconductor when the content (volume fraction) of the bubbles which are the light diffusion elements 4b is changed The luminous efficiency (lm / W) of the light emitting device was calculated by simulation. As a specific condition, the wavelength conversion member 4 was made of the phosphor 4a and the polycarbonate resin as the resin 4c without including the bubbles as the light diffusion element 4b in the wavelength conversion member 4 in the sample 5-1. Then, the wavelength conversion member 4 of Samples 5-2 to 5-7 contains bubbles as the light diffusion element 4b, and the wavelength conversion member 4 is made of the phosphor 4a, the light diffusion element 4b, and the polycarbonate resin as the resin 4c. The content of the light diffusing element 4b was increased as the sample number was increased, and the volume fraction (vol%) of the light diffusing element 4b was increased.

Further, in the simulation of the fifth sample group, it is assumed that the light diffusion element 4b is a bubble and the resin 4c is a polycarbonate resin. Therefore, the refractive index at 450 nm at a measurement temperature of 20 ° C. is 1.00 and the resin 4c is 1.00. 1.58. The density of the light diffusing element 4b was 0.001 g / cm ³ and the density of the resin 4c was 1.2 g / cm ³ . Furthermore, the thickness of the wavelength conversion member 4 itself (that is, the thickness of the resin 4c) was set to 1.00 mm.

In Table 7 below, “volume fraction of light diffusing element 4b (vol%)”, “difference of refractive index × thickness of wavelength converting member 4 itself × volume of light diffusing element 4b” in each sample (semiconductor light emitting device 1). Rate "," use concentration of phosphor 4a (wt%) "," decrease rate of use concentration of phosphor 4a (%) "," emission efficiency (lm / W) ", and" emission efficiency maintenance rate (%) ) ". The “decrease rate (%) of use concentration of phosphor 4a” and “maintenance rate (%) of luminous efficiency” are the same as those defined in Table 3.

As shown in Table 7, in the fifth sample group, the difference in refractive index between the light diffusing element and the base material × the thickness of the light conversion member × the volume fraction of the light diffusing element is 0.415, and the phosphor 4a The concentration used could be reduced to 88.0%, and the luminous efficiency maintenance rate was 90.2%.

Further, when the difference in refractive index between the light diffusing element and the base material × the thickness of the light conversion member × the volume fraction of the light diffusing element exceeds 0.415, the reduction rate of the use concentration of the phosphor 4a is 88.0%. However, it was found that the maintenance ratio of the luminous efficiency was less than 90%. However, even in this case, it is possible to ensure a value (70% or more) of the luminous efficiency maintenance rate that can generally obtain good characteristics.

Assuming a case where barium fluoride is used for the light diffusing element 4b and silicone resin is used for the resin 4c as the sixth sample group, when the content (volume fraction) of barium fluoride which is the light diffusing element 4b is changed The light emission efficiency (lm / W) of each semiconductor light emitting device was calculated by simulation. As a specific condition, the wavelength conversion member 4 was composed of the phosphor 4a and the silicone resin as the resin 4c without including the barium fluoride as the light diffusion element 4b in the wavelength conversion member 4 in the sample 6-1. The wavelength conversion members 4 of the samples 6-2 to 6-20 contain barium fluoride as the light diffusing element 4b, and the wavelength converting members are converted from the phosphor 4a, the light diffusing element 4b, and the silicone resin as the resin 4c. 4, the content of the light diffusing element 4b was increased as the sample number increased, and the volume fraction (vol%) of the light diffusing element 4b was increased.

In the simulation of the sixth sample group, since the light diffusion element 4b is assumed to be barium fluoride and the resin 4c is assumed to be a silicone resin, the light diffusion element 4b is 1.48 as a refractive index at a measurement temperature of 20 ° C. and 450 nm. 4c was set to 1.40. In addition, the density of the light diffusing element 4b was 4.9 g / cm ³ and the density of the resin 4c was 1.0 g / cm ³ . Furthermore, the thickness of the wavelength conversion member 4 itself (that is, the thickness of the resin 4c) was set to 1.00 mm.

Table 8 below shows “volume fraction of light diffusing element 4b (vol%)”, “difference in refractive index × thickness of wavelength conversion member 4 itself × volume of light diffusing element 4b” in each sample (semiconductor light emitting device 1). Rate "," use concentration of phosphor 4a (wt%) "," decrease rate of use concentration of phosphor 4a (%) "," emission efficiency (lm / W) ", and" emission efficiency maintenance rate (%) ) ". The “decrease rate (%) of use concentration of phosphor 4a” and “maintenance rate (%) of luminous efficiency” are the same as those defined in Table 3.

As shown in Table 8, in the sixth sample group, when the refractive index difference between the light diffusing element and the base material × the thickness of the light conversion member × the volume fraction of the light diffusing element is 0.760, the phosphor 4a is used. The concentration could be reduced to 80.8%, and the luminous efficiency maintenance rate was 92.0%.

Further, when the value of the refractive index difference between the light diffusing element and the base material × the thickness of the light conversion member × the volume fraction of the light diffusing element exceeds 1.5, the reduction rate of the use concentration of the phosphor 4a is 85.0%. However, it was found that the maintenance ratio of the luminous efficiency was less than 90%. However, even in this case, it is possible to ensure a value (70% or more) of the luminous efficiency maintenance rate that can generally obtain good characteristics.

Based on the results of Tables 3 to 8, “(absolute value of refractive index difference between light diffusing element 4b and resin 4c) × (wavelength conversion member 4) in each sample from the first sample group to the sixth sample group. Relationship between “thickness of itself” × (volume fraction of light diffusing element 4b) ”and“ (concentration of phosphor 4a) × (thickness of wavelength converting member 4 itself) ”and“ (light diffusing element 4b and resin) The relationship between the absolute value of the difference in refractive index with respect to 4c) × (the thickness of the wavelength conversion member 4 itself) × (the volume fraction of the light diffusing element 4b) ”and“ luminous efficiency ”is graphed. FIG. 5 is a graph representing the former, and FIG. 6 is a graph representing the latter.

As a result of the above-described simulation, when compared with a sample that does not contain the light diffusing element 4b in the wavelength conversion member 4, the content rate of the phosphor 4a is reduced while securing a maintenance efficiency of 70% or higher. As a possible condition, the following condition (2) was found.

0.01 ≦ | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength conversion member [mm]) × (volume fraction of light diffusing element [vol%]) ≦ 1. 0 (2)

Moreover, when compared with the sample which does not contain the light-diffusion element 4b in the wavelength conversion member 4 from the result of the simulation mentioned above, content rate of the fluorescent substance 4a is ensured while ensuring the maintenance rate of the luminous efficiency of 80% or more. The condition shown in the following mathematical formula (3) was found as a condition for reducing the above.

0.01 ≦ | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength conversion member [mm]) × (volume fraction of light diffusing element [vol%]) ≦ 0. 6 (3)

Furthermore, from the result of the simulation described above, the content rate of the phosphor 4a is ensured while maintaining a luminous efficiency maintenance rate of 90% or more when compared with a sample in which the wavelength conversion member 4 does not contain the light diffusion element 4b. The condition shown in the following mathematical formula (4) was found as a condition for reducing the above.

0.01 ≦ | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength conversion member [mm]) × (volume fraction of light diffusing element [vol%]) ≦ 0. 2 (4)

Moreover, based on the result of the simulation described above on the assumption that any one of the above-described mathematical formulas (2) to (4) is satisfied, the light diffusion element 4b has a refractive index of 1.0 or more and 1.9 or less. It is preferable to select a resin 4c having a refractive index of 1.3 or more and 1.7 or less. The difference between the refractive index of the light diffusing element 4b and the refractive index of the resin 4c as the base material is preferably 0.07 or more, more preferably 0.10 or more.

Next, it was found that the reduction ratio of the phosphor 4a was 3.0% to 93% when satisfying the above-described formula (2) and the refractive index conditions of the light diffusing element 4b and the resin 4c. The numerical value is based on the simulation results of Sample 2-4 and Sample 4-16. This is because “(absolute value of refractive index difference between light diffusing element 4b and resin 4c) × (thickness of wavelength converting member 4 itself) × (volume fraction of light diffusing element 4b)” of sample 2-4 is The minimum value satisfying the lower limit value of the above-described formula (2), and “(absolute value of refractive index difference between the light diffusing element 4b and the resin 4c) × (thickness of the wavelength conversion member 4 itself) × This is because “(the volume fraction of the light diffusing element 4 b)” is the maximum value that satisfies the upper limit value of the mathematical formula (2) described above.

Further, it was found that the reduction ratio of the phosphor 4a is 3.0% to 91% when the above-described mathematical formula (3) and the refractive index conditions of the light diffusing element 4b and the resin 4c are satisfied. The numerical value is based on the simulation results of Sample 2-4 and Sample 5-7. This is because “(absolute value of refractive index difference between light diffusing element 4b and resin 4c) × (thickness of wavelength converting member 4 itself) × (volume fraction of light diffusing element 4b)” of sample 2-4 is This is the minimum value satisfying the lower limit value of the mathematical formula (3), and “(absolute value of refractive index difference between the light diffusing element 4b and the resin 4c) × (thickness of the wavelength conversion member 4 itself) × of the sample 5-7 × This is because “(the volume fraction of the light diffusing element 4 b)” is the maximum value that satisfies the upper limit value of the mathematical formula (3) described above.

Furthermore, it was found that the reduction ratio of the phosphor 4a is 3.0% to 86% when the above-described formula (4) and the refractive index conditions of the light diffusing element 4b and the resin 4c are satisfied. The numerical value is based on the simulation results of Sample 2-4 and Sample 5-4. This is because “(absolute value of refractive index difference between light diffusing element 4b and resin 4c) × (thickness of wavelength converting member 4 itself) × (volume fraction of light diffusing element 4b)” of sample 2-4 is The minimum value satisfying the lower limit value of the above-described mathematical formula (4), and “(absolute value of refractive index difference between light diffusing element 4b and resin 4c) × (thickness of wavelength conversion member 4 itself) × of sample 5-4 × This is because “(volume fraction of the light diffusing element 4 b)” is the maximum value that satisfies the upper limit value of the above-described equation (4).

From the above, the wavelength conversion member that emits the emitted light of the same chromaticity without including the light diffusing element 4b as long as the above formula (4) and the refractive index conditions of the light diffusing element 4b and the resin 4c are satisfied. 4, the decrease rate of the content concentration [wt%] of the phosphor 4a is always within the range of 3.0% to 86% with reference to the content concentration [wt%] of the phosphor 4a. The retention rate of the light emission efficiency of the semiconductor light emitting device 1 can be ensured to be 90% or more while reducing the use amount of the light emitting device.

Further, if the above formula (3) and the refractive index conditions of the light diffusing element 4b and the resin 4c are satisfied, the minimum value of the luminous efficiency maintenance ratio is reduced to 80%, but the range of the reduction ratio is 3.0. % To 91%, and the amount of phosphor 4a used can be reduced. Furthermore, if the above-described mathematical formula (2) and the refractive index conditions of the light diffusing element 4b and the resin 4c are satisfied, the minimum value of the luminous efficiency maintenance ratio decreases to 70%, but the range of the reduction ratio is 3 Thus, the amount of phosphor 4a used can be reduced. Note that it is considered that a light emitting device having good characteristics can be provided if the maintenance ratio of the luminous efficiency is 70% or more, preferably 80% or more, more preferably 90% or more, and particularly preferably 95%. That's it.

Further, “(absolute value of the difference in refractive index between the light diffusing element 4b and the resin 4c) × (thickness of the wavelength conversion member 4 itself) × (volume of the light diffusing element 4b” is the value (x) on the horizontal axis in FIG. 5), and the value (y) on the vertical axis in FIG. 5 is “(concentration used of phosphor 4a) × (thickness of wavelength converting member 4 itself)”. When evaluated for (dy / dx), the results in Table 9 below were obtained. As a specific method of calculating the inclination, for each sample, the difference (dx) in the horizontal axis in FIG. 5 and the difference (dy) in the vertical axis in FIG. The slope (dy / dx) was calculated by dividing (dy) by the difference (dx) between the values on the horizontal axis. Here, the difference (dy) in the value on the vertical axis is not the actual difference of “(use concentration of phosphor 4a) × (thickness of wavelength conversion member 4 itself)”, but the decrease rate of use concentration of phosphor ( %) Difference. In each sample group, the sample with the largest sample number (Sample 1-20, Sample 2-19, Sample 3-20, Sample 4-19, Sample 5-7, Sample 6-20) For, the slope is not calculated. Note that values with negative inclinations are uniformly set to zero “0”.

Here, as shown in Table 9, the slope of the sample 2-4 having the minimum value satisfying the lower limit value of the above-described equation (4) is 447, and the maximum value satisfying the upper limit value of the above-described equation (4) is The slope of Sample 5-4 that it had was 19. For this reason, in the range where the slope is relatively small, that is, in the range where the slope is moderately gentle, the variation in the chromaticity of the emitted light due to the change in the thickness of the wavelength conversion member or the change in the phosphor concentration is suppressed. be able to. When Expression (4) described above is shown using the slope in FIG. 5, it can be expressed as the following Expression (5).

19 ≤ dy / dx ≤ 447 (5)

In the above formula (5), x is | (refractive index of the light diffusing element) − (refractive index of the base material) | × (thickness [mm] of the wavelength conversion member) × (volume fraction of the light diffusing element [ vol%]), and y represents the decreasing rate of the concentration of the phosphor 4a used.

Furthermore, considering FIG. 5 and Table 9 comprehensively, in all of the first sample group, the third sample group, the fourth sample group, and the fifth sample group, “(refraction of the light diffusing element 4b and the resin 4c”. The value of (absolute value of rate difference) × (thickness of wavelength conversion member 4 itself) × (volume fraction of light diffusing element 4b) ”(value (x) on the horizontal axis in FIG. 5) is in the range of 0 to 0.02. In FIG. 5, the value of “(concentration of phosphor 4a) × (thickness of wavelength converting member 4 itself)” (value (y) on the vertical axis in FIG. 5) decreases particularly steeply, and the horizontal axis in FIG. Is within the range of 0.02 to 0.04, the value of “(concentration of phosphor 4a) × (thickness of wavelength converting member 4 itself)” (the value on the vertical axis in FIG. 5) y)) sharply decreases, and when the value (x) on the horizontal axis in FIG. 5 is in the range of 0.04 to 0.05, “(the concentration of phosphor 4a used) × ( The value of “the thickness of the wavelength conversion member 4 itself” (the value (y) on the vertical axis in FIG. 5) is decreased, though not as much as the decrease rate in the above-described range. On the other hand, in the range where the value (x) on the horizontal axis in FIG. 5 is 0.05 or more, the value (y) on the vertical axis in FIG. 5 is gradually decreasing or almost not decreasing.

From this, “(absolute value of refractive index difference between light diffusing element 4b and resin 4c) × (thickness of wavelength converting member 4 itself) × (light diffusing element 4b)” is the value (x) on the horizontal axis in FIG. By setting the value of “volume fraction” of 0.02 or more to a value less than 0.02, the variation in the luminous efficiency of the semiconductor light emitting device 1 due to the variation in the content of the phosphor 4a is reduced. Can be reduced. Further, by setting the value (x) on the horizontal axis in FIG. 5 to 0.04 or more, it is possible to further reduce the variation in the light emission efficiency of the semiconductor light emitting device 1 due to the variation in the content of the phosphor 4a. it can. Furthermore, by setting the value (x) on the horizontal axis in FIG. 5 to be 0.05 or more, the variation in the light emission efficiency of the semiconductor light emitting device 1 due to the variation in the content of the phosphor 4a is 0.05. It can reduce reliably compared with the case of less than. As a result, the conversion efficiency of the light emitted from the semiconductor light emitting element changes, so that the light emitted from the semiconductor light emitting element (blue light) and the light converted by the wavelength conversion member (yellow light) Variation in chromaticity of light (white light) mixed and emitted from the semiconductor light emitting device can be reduced. Accordingly, the wavelength conversion member 4 has the following relationship: | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength converting member [mm]) × (volume fraction of light diffusing element [vol%] ) Is preferably 0.02 or more, more preferably the value is 0.04 or more, and particularly preferably, the following formula (6) is satisfied.

0.05 ≦≦ (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength conversion member [mm]) × (volume fraction of light diffusing element [vol%]) ≦ 0. 2 (6)

Here, as shown in Table 9, the slope of the sample 1-7 (dy / dx) is 233, the slope of the sample 2-7 (dy / dx) is 399, and the slope of the sample 4-5 (dy / dx) ) Was 376, and the slope (dy / dx) of Sample 5-2 was 176. When the above equation (6) is shown using the gradient in FIG. 5 in consideration of these inclinations, it can be expressed as the following equation (7).

400 ≤ dy / dx ≤ 447 (7)

In the above formula (7), x is | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength conversion member [mm]) × (volume fraction of light diffusing element [ vol%]), and y represents the decreasing rate of the concentration of the phosphor 4a used.

In addition, although the fluorescent substance 4a mentioned above may also diffuse yellow light, in the numerical formula mentioned above, the fluorescent substance 4a is not included in the light diffusion element 4b, and the fluorescent substance 4a is not considered as a part of the light diffusion element 4b. And

(Actual sample evaluation)
<Examples 1-1 and 1-2>
Next, with respect to the semiconductor light emitting device 1 in the present embodiment, the target chromaticity point of light emitted from the semiconductor light emitting device 1 is changed by changing the mixing ratio of the phosphors 4a and the use concentration (wt%) of the phosphors 4a. Adjustments were made so that (x, y) = (0.46, 0.41). And the luminous efficiency of each semiconductor light-emitting device was actually measured, and the said measurement result was evaluated. As the wiring board 2, white alumina having a reflectance of 90% or more was used. The evaluation result will be described in detail with reference to Table 10.

The raw materials of the resin compositions of Examples 1-1 and 1-2 used for producing the wavelength conversion member 4 are as follows.
Light diffusing element 4b: polymethylsilsesquioxane spherical particles, manufactured by Momentive, trade name “Tospearl 120”, average particle size 2 μm, refractive index 1.42, density 1.3 g / cm ³
Resin 4c: Polycarbonate resin (a polycarbonate resin granule produced by an interfacial polymerization method using bisphenol A as a starting material), manufactured by Mitsubishi Engineering Plastics Co., Ltd., trade name “Iupilon S-3000FN”, viscosity average molecular weight 21,000, density = 1.2 g / cm ³ (23 ° C.), refractive index 1.58
Phosphor 4a: a mixture of a phosphor manufactured by Mitsubishi Chemical Corporation, YAG (yellow phosphor), CASN (red phosphor), SCASN (short wavelength red phosphor), and G-YAG (green phosphor). The mixing ratio is (YAG + G−YAG) :( CASN + SCASN) = 8: 2.

The manufacturing conditions of the resin composition used for the wavelength conversion member 4 and the molding conditions of the wavelength conversion member 4 are as follows.

The phosphor 4a, the light diffusing element 4b, and the resin 4c are blended in predetermined amounts shown in Table 10, mixed with a tumbler mixer, and then cylinder temperature using a 40 mm single-screw extruder (made by Isuzu Processing Co., Ltd., full flight screw). Melting and kneading were performed under the conditions of 280 ° C. setting, screw rotation speed 75 rpm, production rate 18 kg / h, and vacuum vent 0.08 MPa to obtain resin composition pellets. Next, using the obtained pellets, an injection molding machine (“NS40” manufactured by Nissei Co., Ltd.) uses a cylinder temperature of 280 ° C., a mold temperature of 80 ° C., an injection holding time of 3 sec, and a cooling time of 10 sec. The conversion member 4 was produced.

Table 10 below shows “volume fraction of light diffusing element 4b (vol%)”, “difference in refractive index × thickness of wavelength converting member 4 itself × volume of light diffusing element 4b” in each sample (semiconductor light emitting device 1). "Rate", "Used concentration of phosphor 4a (wt%)", and "Luminescence efficiency (lm / W)".

As shown in Table 10, it can be seen that even if the concentration of the phosphor 4a used is changed, a relatively high luminous efficiency can be obtained if any one of the above-described formulas (2) to (4) is satisfied. It was. In this evaluation, when the use concentration (wt%) of the phosphor is decreased, the light emission efficiency is increased, which is different from the simulation result described above. This is because the luminous efficiency of the semiconductor light emitting device 1 is affected by other factors (for example, the mixing ratio of the phosphor 4a) other than the addition of the light diffusing element 4b.

<Examples 2-1 to 2-4, Comparative Example 1>
With respect to the semiconductor light emitting device 1 in the present embodiment, the usage concentration of the phosphor and the change in the light emission efficiency of the semiconductor light emitting device with and without the addition of the light diffusing element 4b were evaluated. The light emitted from the semiconductor light emitting device 1 was adjusted so that the target chromaticity point (x, y) = (0.26, 0.25). And the luminous efficiency of each semiconductor light-emitting device was actually measured, and the said measurement result was evaluated. As the wiring board 2, white alumina having a reflectance of 90% or more was used. The evaluation result will be described in detail with reference to Table 11.

The raw materials of the resin compositions of Examples 2-1 to 2-4 and Comparative Example 1 used for manufacturing the wavelength conversion member 4 are as follows.
Light diffusion element 4b: Alumina particles, manufactured by Micron, trade name “AX3-32”, average particle size 3 μm, refractive index 1.78, density 4.0 g / cm ³
Resin 4c: Silicone resin, manufactured by Toray Dow Corning, trade name “OE6336A / B”, density = 1.0 g / cm ³ (23 ° C.), refractive index 1.42
Phosphor 4a: a phosphor manufactured by Mitsubishi Chemical Corporation, YAG (yellow phosphor)

Phosphor 4a, light diffusing element 4b, and resin 4c were blended in the prescribed amounts shown in Table 11 (total weight 10 g), and defoamed at 1200 rpm for 3 minutes at room temperature using a vacuum defoaming kneader V-mini300 manufactured by EME. The mixture was kneaded to obtain a phosphor-containing silicone resin composition. The obtained resin composition was cast so as to have a diameter of 62 mm and a thickness of 1 mm, and was molded by heating and curing at 150 ° C. for 5 minutes and then at 200 ° C. for 20 minutes, whereby the wavelength conversion member 4 was obtained.

In Table 11 below, “volume fraction of light diffusing element 4b (vol%)”, “difference in refractive index × thickness of wavelength converting member 4 itself × volume of light diffusing element 4b” in each sample (semiconductor light emitting device 1). "Rate", "Relative phosphor usage (Comparative Example 1 is 1.00)", and "Relative luminous flux value (Comparative Example 1 is 1.00)".

If the refractive index of the light diffusing element, the volume fraction of the light diffusing element, and the refractive index of the base material are in the state before the light diffusing element is mixed into the base material, the amount of each material and the manufacturing process are grasped. By doing so, it is possible to accurately calculate (that is, the true value), and it is possible to easily use the above-described mathematical expressions. On the other hand, the refractive index of the light diffusing element, the volume fraction of the light diffusing element, and the refractive index of the base material are from the state after the light diffusing element is mixed into the base material (that is, the state of the wavelength conversion member), It is difficult to calculate accurately. In particular, regarding the volume fraction of the light diffusing element, it is impossible to calculate the actual volume fraction of the light diffusing element from the state after the light diffusing element is mixed into the base material. However, even in a state after the light diffusing element is mixed into the base material, the refractive index of the light diffusing element, the volume fraction of the light diffusing element, and the refractive index of the base material are true by the following method. Value (actual value) can be calculated, and by applying the calculated value to the above formula, the target wavelength conversion member (that is, the light diffusion element is mixed in the base material) The member in a state after being applied) can be verified and evaluated.

Specific verification and evaluation of the light diffusing element includes analysis of the base material (estimating the refractive index from the type of base material), analysis of the light diffusing element (estimating the refractive index from the type of the light diffusing element), and light diffusing element. It is done by quantitative determination. Here, the qualitative analysis of the base material is performed by infrared spectroscopy or the like, and the qualitative analysis of the light diffusing element is performed by SEM-EDS, nuclear magnetic resonance (NMR) or the like, and the quantitative analysis of the light diffusing element. Is performed by image analysis of a cross-sectional SEM image. The qualitative analysis of the base material and the light diffusing element can also be performed by a known method such as IR or pyrolysis GC / MS.

The analysis of the base material is performed using a commercially available infrared spectrometer, for example, NEXUS670 and Nic-Plan manufactured by Thermo Fisher Scientific. By comparing the obtained spectrum with the database, the type of the base material can be specified. Then, the refractive index of the identified base material can be determined by referring to Table 2 described above.

The analysis and quantification of the light diffusion element is performed according to the following procedure. Specifically, a cross section of the wavelength conversion member is created using a cross section polisher manufactured by JEOL, and SEM images of phosphors and light diffusing elements contained in the base material are taken. For SEM, for example, Ultra 55 manufactured by Carl Zeiss may be used.

Here, the phosphor and the light diffusing element are distinguished from each other by SEM-EDS analysis. By qualitative analysis of X-ray diffraction (XRD: X-ray Diffraction), the phosphor candidates included in the wavelength conversion member are previously determined. It is good to narrow down. When silicon or oxygen is observed as the main element of the light diffusing element, the type of the light diffusing element is presumed to be glass or silicone resin. When carbon or oxygen is observed as the main element of the light diffusing element, it is presumed that an organic resin is used, and an acrylic or styrene resin (see Table 1) is used for the light diffusing element. Here, oxygen is detected in addition to carbon in the case of acrylic, but only carbon is detected in the case of styrene (however, a trace amount of oxygen may be detected due to the influence of impurities, etc.) is there). If it is difficult to distinguish between the two by SEM-EDS, the type is identified by NMR or the like. When it is difficult to distinguish between a phosphor using NMR or the like and a light diffusing element due to a low content, etc., it may be dissolved and filtered as necessary. Then, similarly to the determination of the refractive index of the base material, the refractive index of the specified light diffusing element can be determined by referring to Table 1 described above.

Quantification of the light diffusing element is performed by image analysis of the secondary electron image or reflected electron composition image of the SEM. Specifically, first, the phosphor is distinguished from the contrast (brightness) of the secondary electron image or the reflected electron composition image. Here, it is sufficient that the light diffusing element can be specified from the contrast of the secondary electron image or the reflected electron composition image. Therefore, it is not necessary to perform SEM-EDS analysis on all light diffusing elements. The magnification of the cross-sectional SEM image to be photographed is set so that the maximum particle size (diameter) of the observed light diffusing element is 20 times or more the image pixel size. For example, in the case of a light diffusing element particle having a maximum diameter of 2 μm, a cross-sectional SEM image of 0.1 μm or less per pixel is taken. In order to reduce statistical errors, the number of cross-sectional SEM images used for quantification is set so that the total number of light diffusing elements is 1000 or more.

Next, image analysis is performed by binarization processing by a computer. For example, ImageProPlus manufactured by Media Cybernetics is used. Specifically, the total number N of light diffusing elements in the wavelength conversion member and the average area of the light diffusing elements in the cross-sectional SEM image are extracted by binarizing the cross-sectional SEM image, and a circle is assumed from the average area. The value obtained by multiplying the average diameter of the circle calculated by π / 4 is the particle size D [μm] of the light diffusing element, and the total area of the cross-sectional SEM image used in the above calculation is S [μm ² ], The concentration (volume fraction) C [vol%] of the light diffusing element is calculated according to the following formula (8).

It is calculated by the above-described analysis of the base material (estimating the refractive index from the type of base material), analysis of the light diffusing element (estimating the refractive index from the type of light diffusing element), and quantification of the light diffusing element. By applying the values of the refractive index of the light diffusing element, the volume fraction of the light diffusing element, and the refractive index of the base material to any of the above formulas (2) to (4) and (6), The wavelength conversion member (that is, the member in a state after the light diffusing element is mixed into the base material) can be verified and evaluated.

When the target wavelength conversion member is verified and evaluated using the method described above, the true values of the refractive index of the light diffusing element, the volume fraction of the light diffusing element, and the refractive index of the base material are obtained. In contrast, when the wavelength conversion member was verified and evaluated, the error was about 10% to 20%. When the error is 10%, the above formulas (2) to (4) and (6) can be expressed as the following formulas (2 ') to (4') and (6 ').

0.01 ± 0.001 ≦ | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength conversion member [mm]) × (volume fraction of light diffusing element [vol%] ) ≤ 1.0 ± 0.1 (2 ')

0.01 ± 0.001 ≦ | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength conversion member [mm]) × (volume fraction of light diffusing element [vol%] ) ≤ 0.6 ± 0.06 (3 ')

0.01 ± 0.001 ≦ | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength conversion member [mm]) × (volume fraction of light diffusing element [vol%] ) ≤ 0.2 ± 0.02 (4 ')

0.05 ± 0.005 ≦ | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength conversion member [mm]) × (volume fraction of light diffusing element [vol%] )
≦ 0.2 ± 0.02 (6 ′)

Even if the target wavelength conversion member is verified and evaluated using the above-described method from the above formulas (2 ′) to (4 ′) and (6 ′), the evaluation result uses a true value. It was found that there was no inferiority compared to the evaluation results, and an excellent evaluation accuracy equivalent to the evaluation using the true value was realized.

(Effects of this embodiment)
In the wavelength conversion member 4 of the present embodiment, 0.01 ≦ | (refractive index of the light diffusing element 4b) − (refractive index of the resin 4c) | × (thickness [mm] of the wavelength conversion member 4) × (light diffusion) Since the volume fraction of element 4b [vol%]) ≦ 1.0 is satisfied, the phosphor 4a does not decrease the luminous efficiency of the semiconductor light emitting device 1 when it is provided in the semiconductor light emitting device 1. The content can be reduced to reduce the cost. In this case, | (refractive index of light diffusing element 4b) − (refractive index of resin 4c) | × (thickness of wavelength conversion member 4 [mm]) × (volume fraction of light diffusing element 4b [vol%]) If the value is 0.6 or less, the effect (reduction in luminous efficiency and cost reduction) is remarkably exhibited, and if it is 0.2 or less, the effect is remarkably exhibited.

In the wavelength conversion member 4 of the present embodiment, | (refractive index of the light diffusing element 4b) − (refractive index of the resin 4c) | × (thickness [mm] of the wavelength converting member 4) × (light diffusing element 4b). When the value of the volume fraction [vol%] is 0.02 or more, it is possible to reduce the variation in the luminous efficiency of the semiconductor light emitting device 1 due to the variation in the content of the phosphor 4a. In this case, | (refractive index of light diffusing element 4b) − (refractive index of resin 4c) | × (thickness of wavelength conversion member 4 [mm]) × (volume fraction of light diffusing element 4b [vol%]) If the value is 0.04 or more, the effect (reduction in variation in light emission efficiency) is remarkably exhibited, and if the value is 0.05 or more, the effect is remarkably exhibited.

Furthermore, in the semiconductor light emitting device 1 of the present embodiment, the wavelength conversion member 4 is 0.01 ≦≦ | (refractive index of the light diffusing element 4b) − (refractive index of the resin 4c) | × (thickness of the wavelength conversion member 4). [Mm]) × (volume fraction of light diffusing element 4b [vol%]) ≦ 1.0 satisfies the formula of 1.0, so the content of phosphor 4a is reduced without reducing the luminous efficiency and the cost Reduction can be achieved.

Then, when verifying and evaluating the wavelength conversion member 4 included in the semiconductor light emitting device 1, (the volume fraction of the light diffusing element [vol%]) in the above-described mathematical formula is used as the image analysis of the cross-sectional SEM image of the wavelength conversion member 4. Using the results, C = N × 4π / 3 × (D / 2) ³ / (S × D) × 100 (where C: volume fraction [vol%] of light diffusion element 4b, N: cross-sectional SEM image) The total number of light diffusing elements 4b in the wavelength conversion member 4 calculated by the binarization process of [D]: D: average of the light diffusing elements 4b in the cross-sectional SEM image calculated by the binarization process of the cross-sectional SEM image The particle diameter [μm] of the light diffusing element 4b obtained by multiplying the average diameter of the circle calculated from the area by assuming a circle by π / 4, and S: the total area [μm ² ] of the cross-sectional SEM image) Is calculated using the true value of the volume fraction of the light diffusing element 4b. And it is possible to achieve comparable accurate verification and evaluation and for evaluation.

In the present embodiment, the resin 4c as described above is used as the base material of the wavelength conversion member 4. However, the present invention is not limited to this, and glass or the like can also be used.

In this embodiment, the LED chip 3 that emits blue light is used as the light source of the semiconductor light emitting device 1. However, if white light can be emitted from the semiconductor light emitting device 1, the LED chip that emits blue light is used. Without limitation, for example, an LED chip that emits ultraviolet light may be used. In such a case, the wavelength converting member 4 absorbs ultraviolet rays and emits red light, red phosphors that absorb ultraviolet rays and emits green light, and green phosphors that absorb ultraviolet rays and emits blue light, and emits blue light. The blue phosphor is dispersed and held.

The emission peak wavelength of a specific red phosphor is usually 570 nm or more, preferably 580 nm or more, more preferably 585 nm or more, and usually 780 nm or less, preferably 700 nm or less, more preferably 680 nm or less. Is preferred. Among them, as the red phosphor, for example, (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Ca, Sr, Ba) Si (N, O) ₂ : Eu, (Ca, Sr, Ba) ) AlSi (N, O) ₃ : Eu, (Sr, Ba) ₃ SiO ₅ : Eu, (Ca, Sr) S: Eu, SrAlSi ₄ N ₇ : Eu, (La, Y) ₂ O ₂ S: Eu, Eu _{(dibenzoylmethane)} beta-diketone Eu complex such as 3-1,10-phenanthroline complex, a carboxylic acid Eu _complex, K 2 _SiF 6: Mn is _{preferred, (Ca, Sr, Ba)} 2 Si 5 (N , O) ₈ : Eu, (Sr, Ca) AlSi (N, O) ₃ : Eu, SrAlSi ₄ N ₇ : Eu, (La, Y) ₂ O ₂ S: Eu, K ₂ SiF ₆ : Mn Part of Si may be replaced with Al or Na Is more preferable.

The emission peak wavelength of a specific green phosphor is usually 500 nm or more, preferably 510 nm or more, more preferably 515 nm or more, and usually less than 550 nm, preferably 542 nm or less, more preferably 535 nm or less. Is preferred. Among them, as the green phosphor, for example, Y ₃ (Al, Ga) ₅ O ₁₂ : Ce, CaSc ₂ O ₄ : Ce, Ca ₃ (Sc, Mg) ₂ Si ₃ O ₁₂ : Ce, (Sr, Ba) ₂ SiO ₄ : Eu, (Si, Al) ₆ (O, N) ₈ : Eu (β-sialon), (Ba, Sr) ₃ Si ₆ O ₁₂ : N ₂ : Eu, SrGa ₂ S ₄ : Eu, BaMgAl ₁₀ O ₁₇ : Eu and Mn are preferable.

The emission peak wavelength of a specific blue phosphor is usually 420 nm or more, preferably 430 nm or more, more preferably 440 nm or more, usually less than 500 nm, preferably 490 nm or less, more preferably 480 nm or less, and even more preferably 470 nm or less. Particularly preferred are those in the wavelength range of 460 nm or less. Among them, as a blue phosphor, for example, (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu, (Ba, Ca , Mg, Sr) ₂ SiO ₄ : Eu, (Ba, Ca, Sr) ₃ MgSi ₂ O ₈ : Eu are preferred, (Ba, Sr) MgAl ₁₀ O ₁₇ : Eu, (Ca, Sr, Ba) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu, Ba ₃ MgSi ₂ O ₈ : Eu are more preferable, and Sr ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, BaMgAl ₁₀ O ₁₇ : Eu is particularly preferable.

Furthermore, in the present embodiment, the blue light emitted from the LED chip 3 and the yellow light emitted from the phosphor 4a which is a yellow phosphor are synthesized, and pseudo white light is emitted from the semiconductor light emitting device 1. However, since yellow light is the combined light of red light and green light, the phosphor contained in the wavelength conversion member 4 may be replaced with the red phosphor and the green phosphor described above. In such a case, the blue light emitted from the LED chip 3, the red light emitted from the red phosphor, and the green light emitted from the green phosphor are synthesized, and the semiconductor light emitting device 1 is simulated. Will emit white light.

And in the semiconductor light-emitting device 1 in this embodiment, although the LED chip 3 and the wavelength conversion member 4 were arrange | positioned spaced apart, you may arrange | position the wavelength conversion member 4 so that LED chip 3 may be covered.

Even in the modified example as described above, the same effect as in the above-described embodiment can be obtained when the above-described mathematical formula (2) and the refractive index conditions of the light diffusing element 4b and the resin 4c are satisfied. it can.

FIG. 12 is a schematic diagram of a light emitting device according to an embodiment of the present invention.
The light emitting device 100 includes at least a blue semiconductor light emitting element 101 and a wavelength conversion member 103 as its constituent members. The blue semiconductor light emitting element 101 emits excitation light for exciting the phosphor contained in the wavelength conversion member 103.
The blue semiconductor light emitting device 101 usually emits excitation light having a peak wavelength of 425 nm to 475 nm, and preferably emits excitation light having a peak wavelength of 430 nm to 470 nm. The number of blue semiconductor light emitting elements 101 can be appropriately set depending on the intensity of excitation light required by the apparatus.
On the other hand, a purple semiconductor light emitting element can be used instead of the blue semiconductor light emitting element 101. The violet semiconductor light emitting device usually emits excitation light having a peak wavelength of 390 nm to 425 nm, and preferably emits excitation light having a peak wavelength of 395 to 415 nm.

The blue semiconductor light emitting element 1011 is mounted on the chip mounting surface 102 a of the wiring substrate 102. A wiring pattern (not shown) for supplying electrodes to these blue semiconductor light emitting elements 101 is formed on the wiring substrate 102, and constitutes an electric circuit. In FIG. 12, it is displayed that the wavelength conversion member 103 is placed on the wiring board 102, but this is not restrictive, and the wiring board 102 and the wavelength conversion member 103 may be arranged via other members.
For example, in FIG. 13, the wiring substrate 102 and the wavelength conversion member 103 are arranged via the frame body 104. The frame body 104 may have a tapered shape in order to give light directivity. Further, the frame body 104 may be a reflective material.

From the viewpoint of improving the light emission efficiency of the light emitting device 100, the wiring board 102 is preferably excellent in electrical insulation, has good heat dissipation, and preferably has a high reflectance. In addition, a reflective plate having a high reflectance can be provided on a surface where the blue semiconductor light emitting element 101 does not exist or on at least a part of the inner surface of another member connecting the wiring substrate 102 and the wavelength conversion member 103.
The reflectance of the reflector used in such a wiring board or the reflectance of the reflector covering a part of the wiring board is preferably 80% or more, and the area of the part where the reflectance is 80% or more is More preferably, it is 50% or more of the area of the wiring board, more preferably 70% or more, particularly preferably 80% or more, and further, it has a part having a reflectance of 90% or more. Preferably, the area of the part having a reflectivity of 90% or more is more preferably 50% or more of the area of the wiring board, still more preferably 70% or more, and particularly preferably 80% or more. In addition, a reflectance means the reflectance of visible region light.
Similarly, when a frame is used, the reflectance of the reflector used for the frame or the reflectance of the reflector covering a part of the frame is preferably 80% or more, and the reflectance is The area of 80% or more of the part is more preferably 50% or more of the area of the frame body and the wiring board, more preferably 70% or more, and particularly preferably 80% or more. Furthermore, it is preferable to have a part with a reflectance of 90% or more, and the area of the part with a reflectance of 90% or more is more preferably 50% or more of the area of the frame and the wiring board, and 70% or more. More preferably, it is more preferably 80% or more. In addition, a reflectance means the reflectance of visible region light.
An example of a material for achieving such a reflectance is a reflective material in which a filler is contained in a resin. Specifically, metal oxides are contained in reflectors and ceramics that contain metal oxide fillers such as alumina, titania, silicon oxide, zinc oxide, magnesium oxide in silicone resin, polycarbonate resin, polyphthalamide resin, etc. A reflective material or the like is preferable.
Examples of the reflective material containing a metal oxide such as titania in polycarbonate resin include Iupilon EHR3100 and EHR3200.
Examples of the reflective material in which a metal oxide such as alumina or titania is contained in a silicone resin include the reflective materials described in WO2011 / 078239 and WO2011 / 136302.
Moreover, a reflective material in which a metal oxide such as alumina or titania is contained in polyphthalamide is also preferably exemplified.

<Reference example: Light emitting device using a reflective material with high reflectivity>
Same wavelength conversion member (refractive index of the light diffusing element is 1.45, refractive index of the resin is 1.58, volume fraction of the light diffusing element is 0.5 Vol%, the thickness of the wavelength converting member itself is 2.00 mm, ( 1.58-1.45) × 0.5 × 2 = 0.13) on the wiring board (with a reflectance of less than 80%) and the inner wall of the frame (with a reflectance of less than 80%). The improvement in luminous efficiency when a reflective material having a reflectivity of 93 to 95% (on the surface where no semiconductor light emitting element is present in the case of a wiring board) was confirmed by the same light emission and measurement method as described above. The luminescence Lumen value, Ra (color rendering) and CCT (luminescence color temperature) measurement results are shown in Table 12. The reflectance was measured using U-3310 manufactured by Hitachi High-Tech Co., with barium sulfate as a standard sample.

It can be seen that high efficiency can be achieved in a light emitting device using the present wavelength conversion member by using a reflecting material having a high reflectance over a certain ratio.

<Second Embodiment>
In the first embodiment described above, the phosphor 4a and the light diffusing element 4b are mixed in the resin 4c. However, the structure of the wavelength conversion member 4 is not limited to the structure shown in FIG. It may replace with the wavelength conversion member which has a structure, and demonstrates below the wavelength conversion member 24 which has such a structure as 2nd Embodiment. 7 is an enlarged cross-sectional view of a main part of the semiconductor light emitting device 21 shown in the same manner as FIG. 4. The same reference numerals are given to the same components as those in the first embodiment, and the description thereof is omitted.

As shown in FIG. 7, the plurality of phosphors 24a and the plurality of light diffusion elements 24b are contained separately in the resin 24c. A phosphor layer 24d is formed from the plurality of phosphors 24a and the resin 24c, and a light diffusion layer 24e is formed from the plurality of light diffusion elements 24b and the resin 24c. That is, in the wavelength conversion member 24 in the present embodiment, the light diffusion layer 24e in which the resin 24c contains only the light diffusion element 24b is formed on the phosphor layer 24d in which the resin 24c contains only the phosphor 24a. It has a laminated two-layer structure.

In the present embodiment, the phosphor layer 24d is arranged so as to face the LED chip 3. That is, the distance from the LED chip 3 to the phosphor layer 24d is smaller than the distance from the LED chip to the light diffusion layer 24e.

In addition, as shown in FIG. 8, you may arrange | position so that the light-diffusion layer 24e may oppose the LED chip 3. FIG. That is, the distance from the LED chip 3 to the phosphor layer 24d is larger than the distance from the LED chip to the light diffusion layer 24e.

Also in the present embodiment, the same effect as in the first embodiment described above can be obtained when the above-described mathematical formula (2) and the refractive index of the light diffusing element and the resin are satisfied. The semiconductor light emitting device 21 according to the present embodiment has a relatively high luminous efficiency and is suitable for general lighting applications and backlight applications. Furthermore, since the phosphor layer 24d and the light diffusion layer 24e are stacked in contact with each other, it is easy to reduce the size of the semiconductor light emitting device 21.

<Third Embodiment>
In the second embodiment described above, the wavelength conversion member 24 includes a phosphor layer 24d formed from a plurality of phosphors 24a and a resin 24c, and a light diffusion layer 24e formed from a plurality of light diffusion elements 24b and a resin 24c. Had a two-layered structure. However, the structure of the wavelength conversion member 24 is not limited to this, and the wavelength conversion member having the structure as shown in FIG. 9 may be used, and the wavelength conversion member 34 having such a structure is used in the third embodiment. As a form, it demonstrates below. FIG. 9 is an enlarged cross-sectional view of the main part of the semiconductor light emitting device 31 shown in the same manner as FIGS. 4 and 7, and the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted. To do.

As shown in FIG. 9, the resin 34c is separated into two layers through a gap layer 34f. A plurality of phosphors 34a are dispersed and held in one layer of the resin 34c, thereby forming a phosphor layer 34d. A plurality of light diffusion elements 34b are dispersed and held in the other layer of the resin 34c, thereby forming a light diffusion layer 34e. That is, the wavelength conversion member 34 in the present embodiment has a three-layer structure in which the phosphor layer 34d, the gap layer 34f, and the light diffusion layer 34e are sequentially stacked.

In the present embodiment, the phosphor layer 34d is disposed so as to face the LED chip 3. That is, the distance from the LED chip 3 to the phosphor layer 34d is smaller than the distance from the LED chip to the light diffusion layer 34e.

In addition, as shown in FIG. 10, you may arrange | position so that the light-diffusion layer 34e may oppose the LED chip 3. FIG. That is, the distance from the LED chip 3 to the phosphor layer 34d is larger than the distance from the LED chip to the light diffusion layer 34e. Even in such a case, the light emitting efficiency is not reduced as compared with the semiconductor light emitting device 31 described in FIG. 9, and the light emitting efficiency can be sufficiently used as a general lighting application and a backlight application.

Also in the present embodiment, the same effect as in the first embodiment described above can be obtained when the above-described mathematical formula (2) and the refractive index of the light diffusing element and the resin are satisfied. In the present embodiment, the thickness of the wavelength conversion member in the above formulas (2) to (6) is not the entire thickness of the wavelength conversion member 34, but the thickness of the phosphor layer 34d and the thickness of the light diffusion layer 34e. Is the sum of That is, the thickness is obtained by subtracting the thickness of the gap layer 34f from the thickness of the entire wavelength conversion member 34.

1, 21, 31 Semiconductor light emitting device 2 Wiring board 2a Chip mounting surface 3 LED chip (semiconductor light emitting element)
4, 24, 34

Wavelength conversion member

4a, 24a,

34a Phosphor

4b, 24b, 34b Light diffusing element 4c, 24c, 34c Resin (base material)
5 p electrode 6 n electrode 7 wiring pattern 7
8 Wiring pattern 8
24d,

34d phosphor layer

24e, 34e light diffusion layer 34f gap layer 100 semiconductor light emitting device 101 LED chip (semiconductor light emitting element)
102 Wiring board 102a Chip mounting surface 103 Wavelength conversion member

Claims

A wavelength conversion member that wavelength-converts at least part of incident light and emits outgoing light having a wavelength different from that of the incident light;
A phosphor that absorbs at least part of the incident light and emits outgoing light having a wavelength different from that of the incident light;
A light diffusing element that diffuses the incident light and the outgoing light;
A base material for holding the light diffusing element,
0.01 ≦ | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength conversion member [mm]) × (volume fraction of light diffusing element [vol%]) ≦ 1. 0
The wavelength conversion member characterized by satisfying the formula:
The value of | (refractive index of light diffusing element) − (refractive index of base material) | × (wavelength conversion member thickness [mm]) × (volume fraction of light diffusing element [vol%]) in the above equation is: The wavelength conversion member according to claim 1, wherein the wavelength conversion member is 0.6 or less.
The value of | (refractive index of light diffusing element) − (refractive index of base material) | × (wavelength conversion member thickness [mm]) × (volume fraction of light diffusing element [vol%]) in the above equation is: It is 0.2 or less, The wavelength conversion member of Claim 1 characterized by the above-mentioned.
4. The wavelength according to claim 1, wherein a value of | (refractive index of light diffusing element) − (refractive index of base material) | in the mathematical formula is 0.07 or more. 5. Conversion member.
Content concentration [wt%] of the phosphor based on the content concentration [wt%] of the phosphor when a wavelength conversion member that emits emitted light of the same chromaticity without including the light diffusing element is created. The wavelength conversion member according to any one of claims 1 to 4, wherein the decrease ratio is 3.0% to 86%.
The value of | (refractive index of light diffusing element) − (refractive index of base material) | × (wavelength conversion member thickness [mm]) × (volume fraction of light diffusing element [vol%]) in the above equation is: It is 0.04 or more, The wavelength conversion member of any one of Claim 1 thru | or 5 characterized by the above-mentioned.
The value of | (refractive index of light diffusing element) − (refractive index of base material) | × (wavelength conversion member thickness [mm]) × (volume fraction of light diffusing element [vol%]) in the above equation is: It is 0.05 or more, The wavelength conversion member of Claim 6 characterized by the above-mentioned.
28 ≤ dy / dx ≤ 447
x: | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength conversion member [mm]) × (volume fraction of light diffusing element [vol%])
y: Concentration [wt] of the phosphor based on the concentration [wt%] of the phosphor when a wavelength conversion member that emits outgoing light of the same chromaticity without including the light diffusing element is created. The wavelength conversion member according to any one of claims 1 to 7, wherein a numerical expression of a reduction ratio of%] is satisfied.
The wavelength conversion member according to any one of claims 1 to 8, wherein the phosphor and the light diffusing element are mixed in the base material.
9. The phosphor according to claim 1, wherein the phosphor and the light diffusing element are contained separately from each other in the base material, and form a phosphor layer and a light diffusing layer. The wavelength conversion member as described.
The wavelength conversion member according to claim 10, wherein the phosphor layer and the light diffusion layer are laminated while being in contact with each other.
The wavelength conversion member according to claim 10, wherein the base material has a void layer that separates the phosphor layer and the light diffusion layer.
The refractive index of the light diffusing element is 1.0 or more and 1.9 or less,
The wavelength conversion member according to any one of claims 1 to 12, wherein a refractive index of the base material is 1.3 or more and 1.7 or less.
14. The light diffusing element is an inorganic light diffusing material or an organic light diffusing material containing at least one element of the group consisting of silicon, aluminum, titanium, and zirconium. The wavelength conversion member according to any one of the above.
The wavelength conversion member according to claim 14, wherein the organic light diffusing material is an organic light diffusing material containing silicon as an element or an acrylic light diffusing material.
The wavelength conversion member according to any one of claims 1 to 13, wherein the light diffusion element is formed of bubbles.
The wavelength conversion member according to any one of claims 1 to 16, wherein the base material is made of resin or glass.
The wavelength conversion member according to claim 17, wherein the resin is at least one resin selected from the group consisting of a polycarbonate resin, a polyester resin, an acrylic resin, an epoxy resin, and a silicone resin.
The wavelength conversion member according to claim 17, wherein the resin is a polycarbonate resin, and the light diffusion element is polymethylsilsesquioxane particles.
A wiring board;
A semiconductor light emitting device disposed on a mounting surface of the wiring board;
A semiconductor light emitting device comprising a wavelength conversion member that converts the wavelength of at least part of incident light and emits outgoing light having a wavelength different from that of the incident light,
The wavelength conversion member includes a phosphor that absorbs at least a part of incident light and emits outgoing light having a wavelength different from that of the incident light, a light diffusion element that diffuses the incident light and the outgoing light, and the light. A base material holding the diffusing element,
The wavelength conversion member is
0.01 ≦ | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength conversion member [mm]) × (volume fraction of light diffusing element [vol%]) ≦ 1. 0
A semiconductor light emitting device satisfying the following formula:
The value of | (refractive index of light diffusing element) − (refractive index of base material) | × (wavelength conversion member thickness [mm]) × (volume fraction of light diffusing element [vol%]) in the above equation is: 21. The semiconductor light emitting device according to claim 20, wherein the semiconductor light emitting device is 0.6 or less.
The value of | (refractive index of light diffusing element) − (refractive index of base material) | × (wavelength conversion member thickness [mm]) × (volume fraction of light diffusing element [vol%]) in the above equation is: 21. The semiconductor light emitting device according to claim 20, wherein the semiconductor light emitting device is 0.2 or less.
23. The semiconductor according to claim 20, wherein a value of | (refractive index of light diffusing element) − (refractive index of base material) | in the mathematical formula is 0.07 or more. Light emitting device.
Based on the luminous efficiency (lm / W) when the light diffusing element is not included as a reference, the maintenance ratio of the luminous efficiency (lm / W) is 90% or more, and compared with the case where the light diffusing element is not included. 24. The semiconductor light emitting device according to claim 20, wherein the phosphor concentration [wt%] is reduced.
The semiconductor light-emitting device according to any one of claims 20 to 24, wherein the semiconductor light-emitting element and the wavelength conversion member are separated from each other.
The semiconductor light emitting device according to any one of claims 20 to 25, wherein the phosphor and the light diffusing element are mixed in the base material.
The phosphor and the light diffusing element are contained separately from each other in the base material, and form a laminated structure including a phosphor layer and a light diffusing layer. 2. A semiconductor light emitting device according to claim 1.
28. The semiconductor light emitting device according to claim 27, wherein a distance from the semiconductor light emitting element to the phosphor layer is smaller than a distance from the semiconductor light emitting element to the light diffusion layer.
28. The semiconductor light emitting device according to claim 27, wherein a distance from the semiconductor light emitting element to the phosphor layer is larger than a distance from the semiconductor light emitting element to the light diffusion layer.
The refractive index of the light diffusing element is 1.0 or more and 1.9 or less,
30. The semiconductor light emitting device according to claim 20, wherein a refractive index of the base material is 1.3 or more and 1.7 or less.
31. The semiconductor light-emitting device according to claim 20, wherein the base material is made of resin or glass.
32. The semiconductor light emitting device according to claim 31, wherein the resin is at least one resin selected from the group consisting of polycarbonate resin, polyester resin, acrylic resin, epoxy resin, and silicone resin.
32. The semiconductor light-emitting device according to claim 31, wherein the resin is a polycarbonate resin, and the light diffusion element is polymethylsilsesquioxane particles.
34. The light emitted from the semiconductor light emitting element that has not been wavelength-converted by the wavelength conversion member and the light that has been converted by the wavelength conversion member are mixed to radiate white light. The semiconductor light-emitting device of any one of Claims.
35. Any one of claims 20 to 34, wherein a reflector is provided on the wiring substrate of the semiconductor light emitting device, and an area of a portion having a reflectance of 80% or more is 50% or more of the area on the wiring substrate. 2. A semiconductor light emitting device according to claim 1.
The semiconductor light emitting device has a frame, and a reflector is provided on the wiring board and on the wall surface of the frame, and the area of the part having a reflectance of 80% or more is on the wall surface of the frame and on the wiring board. The semiconductor light-emitting device according to claim 20, wherein the semiconductor light-emitting device is 50% or more of the area.
A wiring board;
A semiconductor light emitting device disposed on a mounting surface of the wiring board;
A semiconductor light emitting device comprising a wavelength conversion member that converts the wavelength of at least part of incident light and emits outgoing light having a wavelength different from that of the incident light,
The wavelength conversion member includes a phosphor that absorbs at least a part of incident light and emits outgoing light having a wavelength different from that of the incident light, a light diffusion element that diffuses the incident light and the outgoing light, and the light. A base material holding the diffusing element,
The wavelength conversion member is
0.01 ≦ | (refractive index of light diffusing element) − (refractive index of base material) | × (thickness of wavelength conversion member [mm]) × (volume fraction of light diffusing element [vol%]) ≦ 1. 0
Satisfy the formula of
The (volume fraction [vol%] of the light diffusing element) in the above formula uses the image analysis result of the cross-sectional SEM image of the wavelength conversion member,
C = N × 4π / 3 × (D / 2) 3 / (S × D) × 100
C: Volume fraction [vol%] of the light diffusing element
N: Total number of light diffusing elements in the wavelength conversion member calculated by binarization processing of the cross-sectional SEM image [pieces]
D: of the light diffusing element obtained by multiplying the average diameter of the circle calculated by assuming the circle from the average area of the light diffusing element in the cross-sectional SEM image calculated by the binarization processing of the cross-sectional SEM image by π / 4 Particle size [μm]
S: Total area of cross-sectional SEM image [μm 2 ]
A semiconductor light emitting device calculated from the following formula.