Light-emitting device

Abstract

The present invention provides a light-emitting device that emits red light with high color purity. The light-emitting device that emits red light comprises: a light source; a first layer that covers at least a portion of the light source and contains a fluoride phosphor that converts the wavelength of light emitted from the light source; and a second layer that covers at least a portion of the first layer and contains a nitride phosphor that converts the wavelength of light emitted from the light source and / or the first layer. The maximum luminous peak wavelength in the luminous spectrum of the light-emitting device is set as the center, and the minimum luminous intensity in the luminous spectrum within the range of 15nm or 30nm from the center to the long wavelength side and the short wavelength side, respectively, is set as the reference luminous intensity. When the reference luminous intensity is set to 1, the luminous intensity ratio of the maximum luminous peak wavelength of the light source is within a range of more than 0 and less than 0.1, and the luminous intensity ratio of the maximum luminous peak wavelength exceeds 2.8.

Description

Technical Field

[0001] The present invention relates to a light emitting device. Background Art

[0002] Light emitting devices have been developed that emit white light by combining a light emitting diode (hereinafter also referred to as "LED") with a phosphor. In these light emitting devices, desired luminous colors such as white light or red light are obtained by the principle of light color mixing. These light emitting devices are used in a wide range of fields such as general lighting, vehicle lighting, displays, and backlights for liquid crystals. The light emitting device is required to obtain mixed color light with good color purity. There are known light emitting devices with a narrow half-maximum width of the luminous peak in the luminous spectrum of the light emitting device. The half-maximum width refers to the full width at half maximum (Full Width that Half Maximum: FWHM) of the luminous peak in the luminous spectrum, and refers to the wavelength width of the luminous peak that represents 50% of the maximum value of the luminous peak in the luminous spectrum.

[0003] For example, Patent Document 1 discloses a light-emitting device comprising a blue-emitting LED element and a phosphor that converts the wavelength of light emitted by the LED element and emits yellow light and / or green light. A manganese-activated fluoride phosphor having a narrow half-width is used as the phosphor, thereby reducing the amount of fluoride phosphor used and emitting white light through color mixing of light.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: (Japanese) Patent Publication No. 2012-104814 Summary of the invention

[0007] Problems to be solved by the invention

[0008] An object of one embodiment of the present invention is to provide a light-emitting device that emits red light and has excellent luminous flux and color purity.

[0009] Technical solutions to solve problems

[0010] A first aspect of the present invention provides a light-emitting device that emits red light, comprising: a light source; a first layer that covers at least a portion of the light source and contains a fluoride phosphor, the fluoride phosphor containing at least one of a fluoride complex phosphor activated by manganese and a fluorogermanate phosphor activated by manganese that converts the wavelength of light emitted from the light source; a second layer that covers at least a portion of the first layer and contains a nitride phosphor that converts the wavelength of light emitted from the light source and / or the first layer; and when the fluoride complex phosphor is contained and the fluorogermanate phosphor is not contained, the maximum emission wavelength in the emission spectrum of the light-emitting device is converted to a nitride phosphor. The light peak wavelength is set as the center, and the minimum luminous intensity in the luminous spectrum within the range of 15 nm from the center to the long wavelength side and the short wavelength side respectively is set as the reference luminous intensity. In the case of containing the fluorogermanate phosphor, the maximum luminous peak wavelength in the luminous spectrum of the light-emitting device is set as the center, and the minimum luminous intensity in the luminous spectrum within the range of 30 nm from the center to the long wavelength side and the short wavelength side respectively is set as the reference luminous intensity. When the reference luminous intensity is set to 1, the luminous intensity ratio of the maximum luminous peak wavelength of the light source exceeds 0 and is within the range below 0.1, and the luminous intensity ratio of the maximum luminous peak wavelength exceeds 2.8.

[0011] Effects of the Invention

[0012] According to one embodiment of the present invention, a light-emitting device that emits red light with excellent luminous flux and color purity can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1A This is a schematic cross-sectional view showing a first embodiment of the light emitting device.

[0014] Figure 1B This is a schematic cross-sectional view showing the thickness of the light emitting element, the thickness of the first layer, and the thickness of the second layer in the first embodiment of the light emitting device.

[0015] Figure 2 It is a schematic cross-sectional view showing a second embodiment of the light emitting device.

[0016] Figure 3 FIG. 1 is a schematic cross-sectional view showing a third embodiment of the light emitting device.

[0017] Figure 4 This is a diagram showing the emission spectrum of a fluoride complex phosphor.

[0018] Figure 5 This is a diagram showing the emission spectrum of a fluorogermanate phosphor.

[0019] Figure 6It is a diagram showing the emission spectrum of the nitride phosphor 72-1 ((Ca, Sr, Eu)AlSiN3).

[0020] Figure 7 It is a diagram showing the emission spectrum of the nitride phosphor 72-3 ((Ca, Eu)AlSiN3).

[0021] Figure 8 This is a diagram showing the light emission spectrum of the light emitting device of Example 1 within a wavelength range of 600 nm to 660 nm.

[0022] Fig. 9 This is a diagram showing the maximum emission peak wavelength and the reference emission intensity in the emission spectrum of the light-emitting device of Example 1.

[0023] Fig.10 This is a diagram showing the light emission spectrum of the light emitting device of Example 1 in the wavelength range of 400 nm to 500 nm.

[0024] Fig.11 This is a diagram showing the maximum emission peak wavelength and reference emission intensity in the emission spectrum of the light-emitting device of Example 13.

[0025] Fig.12 This is a diagram showing the light emission spectrum of the light emitting device of Example 13 within the wavelength range of greater than 400 nm and less than 500 nm.

[0026] Fig.13 This is a graph showing the relative luminous flux of the light-emitting devices of Examples 14 and 15 after initial continuous lighting.

[0027] Fig.14 This is a schematic cross-sectional view showing the configuration of the light emitting device of Comparative Example 1.

[0028] Fig.15 This is a schematic cross-sectional view showing the configuration of a light emitting device of Comparative Example 2.

[0029] Fig.16 This is a schematic cross-sectional view showing the configuration of a light emitting device of Comparative Example 3. DETAILED DESCRIPTION

[0030] The light emitting device of the present invention is described below based on an embodiment. However, the embodiment shown below is an example for concretizing the technical idea of ​​the present invention, and the present invention is not limited to the light emitting device below. In addition, the relationship between the color name and the chromaticity coordinate, the relationship between the wavelength range of light and the color name of monochromatic light, etc. are based on JIS Z8110.

[0031] An example of a light emitting device according to an embodiment of the present invention will be described with reference to the drawings. Figure 1AIt is a schematic cross-sectional view showing a light emitting device 101 according to the first embodiment of the present invention.

[0032] The light emitting device 101 includes: a light source 10; a first layer 51 covering at least a portion of the light source 10 and including a fluoride phosphor 71 for converting the wavelength of light emitted from the light source 10; and a second layer 52 covering at least a portion of the first layer 51 and including a nitride phosphor 72 for converting the wavelength of light emitted from the light source 10 and / or the first layer 51. The first layer 51 and the second layer 52 constitute a fluorescent component 50.

[0033] The light emitting device 101 includes a molded body 40. The molded body 40 is integrally molded by a first lead 20, a second lead 30, and a resin portion 42 containing a thermoplastic resin or a thermosetting resin and constituting a side wall of the molded body 40. The molded body 40 forms a recess 40r having a bottom surface and a side surface. A light source 10 is placed on the bottom surface of the recess 40r. The light source 10 is preferably a light emitting element, and the light source 10 has a pair of positive and negative electrodes, and the pair of positive and negative electrodes are respectively electrically connected to the first lead 20 and the second lead 30 via a wire 60. The light emitting device 101 can receive power supply from the outside via the first lead 20 and the second lead 30 and emit light.

[0034] light source

[0035] The light source 10 preferably uses a semiconductor light emitting element, and more preferably uses a GaN-based semiconductor light emitting element. By using a GaN-based semiconductor light emitting element as a light source, a light emitting device with high efficiency, high linearity relative to input, and strong mechanical impact can be formed. For example, a nitride-based semiconductor (In x Al Y Ga 1-X-Y A GaN-based semiconductor light-emitting element with N, 0≦X, 0≦Y, X+Y≦1).

[0036] The light emission peak wavelength of the light source 10 is preferably within a range of 400 nm to 480 nm, and more preferably within a range of 420 nm to 460 nm.

[0037] In the case where the light source 10 is a light-emitting element, when the second surface 10b opposite to the first surface 10a on which a pair of electrodes is formed is placed on the first lead 20 which is the bottom surface of the recess 40r, and the light source 10 is installed face up, the first surface 10a on which a pair of electrodes is formed of the light source 10 mainly becomes a light extraction surface.

[0038] First floor

[0039] The first layer 51 covers at least a portion of the light source 10, and constitutes the fluorescent member 50 together with the second layer 52. The first layer 51 preferably contains a resin or glass and a fluoride phosphor 71 that converts the wavelength of light emitted from the light source 10. The first layer 51 may also contain other phosphors other than the fluoride phosphor 71 that convert the wavelength of light from the light source 10 and emit red light. The first layer 51 covers at least a portion of the light extraction surface of the light source 10. The first layer 51 may be arranged in a manner that covers the entire surface of the light extraction surface of the light source 10, or may be arranged in a manner that covers a portion of the light extraction surface of the light source 10. The first layer 51 is preferably arranged in a manner that contacts at least a portion of the light source 10. When the first layer 51 is arranged in a manner that contacts at least a portion of the light source 10, it is easier to absorb the light emitted from the light source 10 than when the first layer 51 is arranged at a distance from the light source 10, and the wavelength conversion can be efficiently performed, so that red light emission with increased luminous flux can be obtained. The fluoride phosphor 71 contained in the first layer 51 contains at least one of a fluoride complex phosphor activated by manganese (also referred to as a "Mn-activated fluoride complex phosphor") and a fluorogermanate phosphor activated by manganese (also referred to as a "Mn-activated MGF phosphor"). Sometimes the first layer 51 contains a Mn-activated fluoride complex phosphor but does not contain a Mn-activated MGF phosphor. Sometimes the first layer 51 does not contain a Mn-activated fluoride complex phosphor but contains a Mn-activated MGF phosphor. Sometimes the first layer 51 contains both a Mn-activated fluoride complex phosphor and a Mn-activated MGF phosphor.

[0040] Fluoride phosphor

[0041] By containing a fluoride phosphor including at least one of a Mn-activated fluoride complex phosphor and a Mn-activated MGF phosphor in the first layer, the luminous flux of the red light-emitting phosphor can be increased.

[0042] Mn activated fluoride complex phosphor

[0043] Examples of Mn-activated fluoride complex phosphors include: +A fluoride complex phosphor activated by Mn and at least one element selected from the group consisting of elements of Group IVB of the periodic table and elements of Group VIA of the periodic table. The Mn-activated fluoride complex phosphor preferably absorbs light from a light source having a luminescence peak wavelength, for example, in the range of 400 nm to 480 nm, wherein the peak wavelength is preferably in the range of 610 nm to 650 nm, and more preferably in the range of 615 nm to less than 645 nm. The half-peak width of the Mn-activated fluoride complex phosphor is relatively narrow. Specifically, the half-peak width in the luminescence spectrum of the Mn-activated fluoride complex phosphor is less than 20 nm, preferably less than 10 nm, and more preferably less than 5 nm. The Mn-activated fluoride complex phosphor may also be a phosphor having multiple peaks in the luminescence spectrum in the range of 610 nm to 650 nm. By containing a Mn-activated fluoride complex phosphor in the first layer, the luminous flux of the red luminescent light-emitting device can be increased.

[0044] The Mn-activated fluoride complex phosphor preferably has a composition represented by the following formula (I).

[0045] A2[M a 1-a Mn 4+ a F6](I)

[0046] (In formula (I), A is an alkali metal element and NH4 + At least one element selected from the group consisting of a is at least one element selected from the group consisting of elements of Group IVB of the periodic table and elements of Group VIA of the periodic table, and a is a number satisfying 0<a<0.2. )

[0047] The Mn-activated fluoride complex phosphor is preferably a particle. In the case where the Mn-activated fluoride complex phosphor is a particle, the average particle size of the Mn-activated fluoride complex phosphor particles is preferably within a range of 10 μm or more and 90 μm or less, more preferably within a range of 15 μm or more and 70 μm or less, and further preferably within a range of 20 μm or more and 60 μm or less. The average particle size of the phosphor particles can be measured by the Fisher Sub-Sieve Sizer method (also known as the "FSSS method"). The FSSS method is a type of air permeation method, which is a method for measuring the specific surface area using the air flow resistance and mainly obtaining the particle size of the primary particles. The average particle size measured by the FSSS method is the Fisher Sub-Sieve Sizer's Number. When the Mn-activated fluoride complex phosphor is a particle and the average particle size measured by the FSSS method is within a range of 10 μm or more and 90 μm or less, the light from the light source can be efficiently wavelength-converted and red light emission can be performed more efficiently. When the Mn-activated fluoride complex phosphor is in the form of particles and the average particle size is less than 10 μm, the wavelength of light from the light source may not be efficiently converted. When the Mn-activated fluoride complex phosphor is in the form of particles and the average particle size exceeds 90 μm, it may be difficult to handle when forming the first layer, and the arrangement of the Mn-activated fluoride complex phosphor in the first layer may be uneven.

[0048] The average particle size of the fluoride phosphor particles contained in the first layer when the fluoride phosphor is a particle is preferably larger than the average particle size of the nitride phosphor particles contained in the second layer when the nitride phosphor is a particle. When the average particle size of the fluoride phosphor particles contained in the first layer is larger than the average particle size of the nitride phosphor particles contained in the second layer, in the light source, i.e., the light-emitting element, the first layer, and the second layer, which are arranged in a manner perpendicular to the direction of gravity, the fluoride phosphor in the first layer is easily arranged on the light-emitting element side by natural sedimentation or centrifugal sedimentation, and the nitride phosphor in the second layer is also easily arranged on the light-emitting element and the first layer side.

[0049] Mn activated MGF phosphor

[0050] The Mn-activated MGF phosphor contains magnesium oxide, an oxide containing at least one element selected from the group consisting of alkali metal elements and rare earth metal elements, magnesium fluoride, germanium oxide, and an oxide containing at least one element selected from the VA group of the periodic table. The Mn-activated MGF phosphor absorbs light from a light source having a peak emission wavelength in the range of, for example, 400 nm to 480 nm, preferably has a peak emission wavelength in the range of 640 nm to 680 nm, more preferably has a peak emission wavelength in the range of 640 nm to 670 nm, and more preferably has a peak emission wavelength in the range of 645 nm to 670 nm. Specifically, the half-peak width of the Mn-activated MGF phosphor is 30 nm or less, preferably 28 nm or less, and more preferably 25 nm or less. The Mn-activated MGF phosphor may also be a phosphor having multiple peaks in the range of 640 nm to 680 nm in the emission spectrum. By containing the Mn-activated MGF phosphor in the first layer, the luminous flux of the red light-emitting device can be increased.

[0051] The Mn-activated MGF phosphor preferably has a composition represented by any one of the following formulas (II-I) and (II-II).

[0052] 3.5MgO·0.5MgF2·GeO2: Mn (II-I)

[0053] (ij)MgO·(j / 2)M b 2O3·kMgF2·mCaF2·(1-n)GeO2·(n / 2)M c 2O3:zMn 4+ (II-II)

[0054] (In formula (II-II), M b is at least one element selected from the group consisting of Li, Na, K, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, and M c is at least one element selected from the group consisting of Al, Ga and In, and i, j, k, m, n and z are numbers satisfying 2≦i≦4, 0≦j<0.5, 0<k<1.5, 0≦m<1.5, 0<n<0.5, and 0<z<0.05 respectively. )

[0055] Second floor

[0056] The second layer 52 covers at least a portion of the first layer 51, and together with the first layer 51, constitutes the fluorescent component 50. The second layer 52 preferably contains a resin or glass, and a nitride phosphor 72 that converts the wavelength of light emitted from the light source 10 and / or the first layer 51. The second layer 52 may also contain other phosphors other than the nitride phosphor 72 that convert the wavelength of light from the light source 10 and emit red light. The nitride phosphor 72 may use a single nitride phosphor, or may use two or more nitride phosphors with different phosphor compositions. The second layer 52 is preferably configured in contact with at least a portion of the first layer 51. When the second layer 52 is configured in contact with at least a portion of the first layer 51, it is easy to absorb light emitted from the first layer 51 or light passing through the first layer 51, and it is easy to absorb light emitted from the light source 10 and / or the first layer 51, and it is possible to efficiently convert the wavelength to obtain red light emission with increased luminous flux, compared with the case where the second layer 52 is configured at a distance from the first layer 51.

[0057] Nitride phosphor

[0058] As nitride phosphors, there can be mentioned: a nitride phosphor containing at least one of calcium and strontium, silicon, and aluminum in the composition and activated by europium; or a nitride phosphor containing at least one element selected from the group consisting of alkaline earth metal elements, at least one element selected from the group consisting of alkali metal elements, and aluminum in the composition and activated by europium. The nitride phosphor is preferably a nitride phosphor that easily absorbs light from a light source, for example, light from a light source having a peak emission wavelength in the range of 400 nm to 480 nm, and contains at least one of calcium and strontium, silicon, and aluminum in the composition and activated by europium. The nitride phosphor easily and efficiently absorbs light emitted from the light source, and light in a specific wavelength range does not substantially escape from the light-emitting device, and the light emitted from the light source is wavelength-converted to obtain red light with good color purity. The light in the wavelength range that does not substantially escape from the light-emitting device may also be, for example, light from a light source having a peak emission wavelength in the range of 400 nm to 480 nm. Light in a specific wavelength range does not substantially escape from the light-emitting device means that, with the maximum luminous peak wavelength in the luminous spectrum of the light-emitting device containing a fluoride phosphor in the first layer and a nitride phosphor in the second layer as the center, and the minimum luminous intensity in the luminous spectrum within the range of 15 nm from the center to the long wavelength side and the short wavelength side respectively as the reference luminous intensity, when the above-mentioned reference luminous intensity is set to 1, the luminous intensity ratio of the maximum luminous peak wavelength of the above-mentioned light source is within the range greater than 0 and less than 0.1.

[0059] A nitride phosphor containing at least one of calcium and strontium, silicon, and aluminum and activated by europium, or a nitride phosphor containing at least one element selected from the group consisting of alkaline earth metal elements, aluminum and activated by europium preferably absorbs light from a light source having a peak emission wavelength in the range of not less than 400 nm and not more than 480 nm, and has a peak wavelength in the range of not less than 620 nm and not more than 660 nm.

[0060] The nitride phosphor is preferably a particle. In the case where the nitride phosphor is a particle, the average particle size of the nitride phosphor measured by the FSSS method is preferably within the range of 5 μm to 50 μm, more preferably within the range of 10 μm to 40 μm, and further preferably within the range of 15 μm to 35 μm. When the nitride phosphor is a particle and the average particle size measured by the FSSS method is within the range of 5 μm to 50 μm, the light from the light source is efficiently absorbed, and the light in a specific wavelength range does not substantially escape from the light-emitting device, and the light emitted from the light source is wavelength-converted to obtain red light with good color purity. When the nitride phosphor is a particle and the average particle size is less than 5 μm, there is a case where the efficiency of the wavelength conversion of the light from the light source is reduced. When the nitride phosphor is a particle and the average particle size exceeds 50 μm, the number of phosphors per unit mass contained in the second layer decreases, and the scattering of light in the second layer decreases. For example, there is a case where it is difficult to perform wavelength conversion in a manner that the light from the light source does not substantially escape.

[0061] The nitride phosphor preferably has a composition represented by the following formula (III). When a nitride phosphor having a composition represented by formula (III) is used, it is easy to absorb light emitted from a light source, light having a peak emission wavelength in the range of 400 nm to 480 nm, and can suppress the light emitted from the light source from escaping from the light-emitting device without wavelength conversion, thereby obtaining red light with good color purity.

[0062] (Ca 1-s-t Sr s Eu t ) x Al u Si v N w (III)

[0063] (In formula (III), s, t, u, v, w and x are numbers satisfying 0≦s<1, 0<t<1.0, 0<s+t<1.0, 0.8≦x≦1.0, 0.8≦u≦1.2, 0.8≦v≦1.2, 1.9≦u+v≦2.1, 2.5≦w≦3.5 respectively.)

[0064] The nitride phosphor may be a nitride phosphor activated by Eu and having a composition represented by the following formula (IV).

[0065] (Ca b Sr 1-b-c-d Ba c Eu d ) e M d f Al3N g (IV)

[0066] (In formula (IV), M d is at least one alkali metal element selected from the group consisting of Li, Na, K, Rb and Cs, and b, c, d, e, f and g are numbers satisfying 0≦b<1.0, 0.001<c≦0.1, 0≦d≦0.2, 3.0≦e≦5.0, 0.8≦f≦1.05, and 0.8≦g≦1.05 respectively.)

[0067] The nitride phosphor may be a nitride phosphor activated by Eu and having a composition represented by the following formula (V).

[0068] M e h M f o Eu p Al3N q (V)

[0069] (Where M e is at least one element selected from the group consisting of Sr, Ca, Ba and Mg, and M f is at least one element selected from the group consisting of Li, Na and K, and h, o, p and q are numbers satisfying 0.80≦h≦1.1, 0.4≦o≦1.8, 0.001<p≦0.1, 1.5≦q≦5.0 respectively.

[0070] Resin

[0071] The resin used in the first layer 51 or the second layer 52 is preferably at least one selected from the group consisting of silicone resin, modified silicone resin, epoxy resin and modified epoxy resin. Among them, the resin used in the first layer 51 or the second layer 52 is more preferably a silicone resin or a modified silicone resin with excellent heat resistance and weather resistance. As silicone resins, dimethyl silicone resin, phenyl-methyl silicone resin and diphenyl silicone resin can be mentioned. The resin used in the first layer 51 or the second layer 52 can also be a single resin or a combination of two or more. The resin contained in the first layer 51 or the second layer 52 can also be the same resin or different resins. In order to efficiently convert the wavelength of light emitted from the light source or the first layer through the second layer 52, the difference in refractive index between the first layer 51 and the second layer 52 is preferably small. In order to reduce the difference in refractive index, it is preferred to use the same type of resin.

[0072] Glass

[0073] Examples of the glass used for the first layer 51 or the second layer 52 include borosilicate glass, quartz glass, sapphire glass, calcium fluoride glass, aluminoborosilicate glass, oxynitride glass, and chalcogenide glass.

[0074] The light emitting device emits the following light: with the maximum peak wavelength of light in the light spectrum of the light emitting device as the center, the minimum light emission intensity in the light emission spectrum within the range of 15 nm or 30 nm from the center to the long wavelength side and the short wavelength side respectively is set as the reference light emission intensity, and when the above-mentioned reference light emission intensity is set to 1, the light emission intensity ratio of the maximum peak wavelength of light emitted by the light source is within the range of more than 0 and less than 0.1, and the light emission intensity ratio of the maximum peak wavelength exceeds 2.8. When the maximum peak wavelength of light in the light spectrum of the light emitting device is less than 645 nm, the reference light emission intensity is preferably the minimum light emission intensity in the light emission spectrum within the range of 15 nm from the center to the long wavelength side and the short wavelength side respectively with the maximum peak wavelength as the center. In addition, when the maximum peak wavelength of light in the light spectrum of the light emitting device is greater than 645 nm, the reference light emission intensity is preferably the minimum light emission intensity in the light emission spectrum within the range of 30 nm from the center to the long wavelength side and the short wavelength side respectively with the maximum peak wavelength as the center.

[0075] In the emission spectrum of the light-emitting device, the maximum emission peak wavelength is within the wavelength range of the red region. In the emission spectrum of the light-emitting device, the maximum emission peak wavelength is preferably within the range of 610 nm to 670 nm, and more preferably within the range of 620 nm to 670 nm. In the emission spectrum of the light-emitting device, the maximum emission peak mainly originates from the red emission emitted from the monofluoride phosphor of the Mn-activated fluoride complex phosphor or the Mn-activated MGF phosphor. In the emission spectrum of the light-emitting device, the minimum emission intensity in the emission spectrum within the range of 15 nm or 30 nm from the maximum emission peak wavelength to the long wavelength side and the short wavelength side, respectively, with the maximum emission peak wavelength as the center, is also within the wavelength range of the red region, and is considered to be mainly derived from the red emission emitted from the nitride phosphor. In the emission spectrum of the light-emitting device, it is difficult to distinguish between the spectrum of red emission originating from a fluoride phosphor of a Mn-activated fluoride complex phosphor or a Mn-activated MGF phosphor and the spectrum of red emission originating from a nitride phosphor. In the emission spectrum within the range from the maximum emission peak wavelength to the minimum emission intensity of 15 nm or 30 nm on the long wavelength side and the short wavelength side, respectively, there is a case where the spectrum of red emission originating from the nitride phosphor and the spectrum of red emission originating from a fluoride phosphor of a Mn-activated fluoride complex phosphor or a Mn-activated MGF phosphor are mixed.

[0076] The light-emitting device sets the minimum light emission intensity in the light emission spectrum within the range of 15 nm or 30 nm on the long wavelength side and the short wavelength side, respectively, from the maximum light emission peak wavelength in the light emission spectrum as a reference light emission intensity, and emits light with a light emission intensity ratio of more than 0 and less than 0.1 at the maximum light emission peak wavelength of the light source when the reference light emission intensity is set to 1. In the light emission spectrum of the light-emitting device, when the light emission intensity ratio of the maximum light emission peak wavelength of the light source to the reference light emission intensity exceeds 0 and is less than 0.1, the light emitted from the light-emitting device does not substantially contain the light from the light source, and when the light from the light source is light in the blue region of more than 400 nm and less than 480 nm, the blue light does not substantially escape from the light-emitting device, and thus red light emission with high color purity is obtained.

[0077] The light emitting device emits the following light: when the minimum luminous intensity in the luminous spectrum within the range of 15nm or 30nm from the maximum luminous peak wavelength to the long wavelength side and the short wavelength side in the luminous spectrum is set as the reference luminous intensity and the reference luminous intensity is set to 1, the luminous intensity ratio of the maximum luminous peak wavelength exceeds 2.8. When the reference luminous intensity in the luminous spectrum is set to 1, the light emitting device emits light with a luminous intensity ratio of preferably 3.0 or more and 12.0 or less, and more preferably 3.5 or more and 11.0 or less. When the reference luminous intensity in the luminous spectrum is set to 1, if the luminous intensity ratio of the maximum luminous peak wavelength exceeds 2.8, the light emitting device emits red light with high luminous flux. The more the main wavelength of the red light emitted from the light emitting device moves to the long wavelength side, the further away from the vicinity of 555nm where the luminous efficiency is the highest, and there is a tendency that the luminous efficiency becomes lower and the luminous flux decreases. Even in the case where the main wavelength moves to the long wavelength side, if the luminous intensity of the maximum luminous peak wavelength when the reference luminous intensity in the luminous spectrum is set to 1 exceeds 2.8, the light emitting device emits red light with high luminous flux. In the light-emitting device, when the light-emitting intensity ratio of the maximum light-emitting peak wavelength is 3.0 or more and 12.0 or less in the light-emitting spectrum, the light-emitting device emits red light with higher light flux and higher color purity when the light-emitting intensity ratio of the maximum light-emitting peak wavelength is 3.0 or more and 11.0 or less when the light-emitting device contains a Mn-activated fluoride complex phosphor in the first layer and does not contain a Mn-activated MGF phosphor, and when the light-emitting device uses the minimum light-emitting intensity in the light-emitting spectrum within the range of 15 nm from the maximum light-emitting peak wavelength to the long wavelength side and the short wavelength side as the reference light-emitting intensity and the reference light-emitting intensity is 1, the light-emitting device emits red light with higher light flux and higher color purity. The dominant wavelength is the wavelength of the point where the chromaticity coordinates (x=0.333, y=0.333) of white light and the chromaticity coordinates (x, y) of light emitted by the light-emitting device are connected by a straight line and the extended line intersects the spectrum locus.

[0078] The fluoride phosphor 71 contained in the first layer 51 absorbs light from a light source having a peak emission wavelength in the range of, for example, 400 nm to 480 nm, and emits red light. The absorption of the light from the light source having a peak emission wavelength in the range of, for example, 400 nm to 480 nm by the fluoride phosphor 71 is lower than that of the nitride phosphor 72 contained in the second layer 52, and the light from the light source is not completely absorbed, so that the light from the light source escapes from the first layer 51. The light from the light source 10 that is not absorbed by the fluoride phosphor 71 contained in the first layer 51 and escapes from the first layer 51 is absorbed by the nitride phosphor 72 contained in the second layer 52 that absorbs the light from the light source 10 better than the fluoride phosphor 71, and the blue light from the light source does not substantially escape from the light emitting device 101. The light from the light source 10 is wavelength-converted by the fluoride phosphor 71 and the nitride phosphor 72, and the light emitting device emits red light with high color purity and high luminous flux. For example, the refractive index of the fluoride phosphor 71 contained in the first layer 51 is in the vicinity of 1.3 to 1.4, and the refractive index of the resin contained in the first layer 51 is in the vicinity of 1.4 to 1.5, and the refractive index difference is small. Therefore, when the particles of the fluoride phosphor are irradiated with light, the light easily passes through the particles of the fluoride phosphor. In addition, even if a plurality of particles of the fluoride phosphor are irradiated with light, the proportion reflected by each particle of the fluoride phosphor is small, and the optical path length becomes short, so only a proportion lower than the actual reflectivity is reflected. In contrast, the refractive index of the nitride phosphor 72 contained in the second layer 52 is in the vicinity of 2.0 to 2.3, and the refractive index of the resin contained in the second layer 52 is in the vicinity of 1.4 to 1.5, and the refractive index difference is larger than that of the fluoride phosphor. Therefore, when the particles of the nitride phosphor are irradiated with light, the light is less likely to pass through the particles of the nitride phosphor than in the case of the fluoride phosphor. In addition, when a plurality of particles of nitride phosphors are irradiated with light, a large proportion of light is reflected by each particle of the nitride phosphor, light is scattered, and the optical path length becomes longer, so that light is reflected at a proportion higher than the actual reflectivity. For example, when a light source having a luminescence peak near 450nm is used as a light source, the fluoride phosphor 71 contained in the first layer 51 absorbs more than 50% and less than 90% of the light from the light source, but reflects or transmits more than 10% of the light from the light source. In contrast, the nitride phosphor 72 contained in the second layer 52 absorbs more than 90% of the light from the light source, but reflects or transmits only less than 8% of the light from the light source. The reflection spectrum and excitation spectrum of the phosphor are always used as reference values.

[0079] Therefore, when a mixture of a fluoride phosphor and a nitride phosphor is used as the resin, the proportion of light from the light source passing through the mixture is large, and the light from the light source is missed, making it difficult to obtain a light-emitting device that emits red light with high color purity. In contrast, in this embodiment, specific phosphors are mixed in the first layer and the second layer, and the order of their arrangement is determined, thereby obtaining a light-emitting device that emits red light with high color purity.

[0080] The light-emitting device is preferably a light-emitting device that emits red light, and comprises: a light source; a first layer covering at least a portion of the above-mentioned light source and containing a Mn-activated MGF phosphor that converts the wavelength of light emitted from the light source; a second layer covering at least a portion of the above-mentioned first layer and containing a nitride phosphor that converts the wavelength of light emitted from the above-mentioned light source and / or the above-mentioned first layer; the maximum luminous peak wavelength in the luminous spectrum of the light-emitting device is set as the center, and the minimum luminous intensity in the luminous spectrum within the range of 30 nm from the above-mentioned center to the long wavelength side and the short wavelength side respectively is set as a reference luminous intensity, when the above-mentioned reference luminous intensity is set to 1, the luminous intensity ratio of the maximum luminous peak wavelength of the above-mentioned light source is within the range of greater than 0 and less than 0.1, and the luminous intensity ratio of the above-mentioned maximum luminous peak wavelength is greater than 2.8.

[0081] The amount of the fluoride phosphor or nitride phosphor in the first layer or the second layer relative to the resin or glass is preferably within the range of 20 to 200 parts by mass, more preferably within the range of 40 to 180 parts by mass, and further preferably within the range of 60 to 180 parts by mass. When the fluoride phosphor contained in the first layer is within the range of 20 to 200 parts by mass relative to 100 parts by mass of the resin or glass contained in the first layer, red light emission with high luminous flux can be obtained. If the nitride phosphor contained in the second layer is within the range of 20 to 200 parts by mass relative to 100 parts by mass of the resin or glass contained in the second layer, light emitted from the light source and / or the first layer is efficiently absorbed and wavelength converted to obtain red light emission with high color purity.

[0082] With respect to the mass ratio of the fluoride phosphor contained in the first layer to the nitride phosphor contained in the second layer, when the nitride phosphor is 100 parts by mass, the fluoride phosphor is preferably in the range of 20 parts by mass or more and 200 parts by mass or less, more preferably in the range of 40 parts by mass or more and 180 parts by mass or less, and further preferably in the range of 60 parts by mass or more and 180 parts by mass or less. If the mass ratio of the fluoride phosphor contained in the first layer to the nitride phosphor contained in the second layer is within the above range, red light emission with a high luminous flux can be obtained.

[0083] The first layer or the second layer may contain other components besides the phosphor, resin or glass, such as fillers, light stabilizers, colorants, etc. Examples of the filler include silicon dioxide, barium titanate, titanium oxide, aluminum oxide, and the like.

[0084] The thickness of the first layer is set to T1, and the thickness of the second layer is set to T2. In the case where the light source is a light-emitting element, it is preferred that the total thickness T1+T2 of the first layer and the second layer is larger than the thickness Te of the light-emitting element. The total thickness of the first layer and the second layer is preferably a thickness in the range of 1.1 times or more and 3 times or less, more preferably a thickness in the range of 1.3 times or more and 2.6 times or less, and further preferably a thickness in the range of 1.6 times or more and 2.3 times or less. If the total thickness T1+T2 of the first layer and the second layer is a thickness in the range of 1.1 times or more and 3 times or less relative to the thickness Te of the light-emitting element, it is easy to absorb the light emitted from the light source by the first layer, and the wavelength conversion can be performed efficiently to emit red light with increased luminous flux. In the second layer, it is also easy to efficiently absorb the light emitted from the light source, and the light in a specific wavelength range will not substantially escape from the light-emitting device. The light emitted from the light source is wavelength-converted, and red light with good color purity is emitted. Figure 1A In the light emitting device 101 of the first embodiment shown in FIG. Figure 1B As shown, regarding the thickness of the light-emitting element 10, the thickness between the surface 10b of the light-emitting element 10 placed on the first lead 20 and the first surface 10a on which a pair of electrodes facing each other is formed is referred to as the thickness Te of the light-emitting element 10. In the light-emitting device 102 of the second embodiment and the light-emitting device 103 of the third embodiment described later, the thickness of the light-emitting element 10 refers to the thickness between one second surface 10b of the light-emitting element 10 and the other first surface 10a facing each other. Figure 1BIn the light emitting device 101 of the first embodiment shown, the total thickness T1+T2 of the first layer 51 and the second layer 52 may be within a range of 1.1 to 3 times the thickness Te of the light emitting element 10 at all locations on the first surface 10a of the light emitting element 10 on the same line in a direction perpendicular to the first surface 10a of the light emitting element 10. The total thickness of the first layer 51 and the second layer 52 can generally be measured as the total thickness T1+T2 of the first layer 51 and the second layer 52 by taking the distance from the first surface 10a of the light emitting element 10 that is opposite to the surface 10b on which the first lead 20 is placed, as the total thickness T1+T2 of the first layer 51 and the second layer 52. For example, when the thickness of the light emitting element is 150 μm, the total thickness of the first layer and the second layer is preferably within a range of 165 to 450 μm.

[0085] The thickness T1 of the first layer 51 may be greater than the thickness T2 of the second layer 52. When the thickness T2 of the second layer 52 is set to 1, the thickness T1 of the first layer 51 may be within a range of 1.1 times or more and 5 times or less, 1.2 times or more and 4.5 times or less, 1.3 times or more and 4 times or less, 3.5 times or less, 3 times or less, or 2 times or less. In the case where the light source is the light emitting element 10, Figure 1A In the light emitting device 101 of the first embodiment shown in FIG. Figure 1B As shown in FIG. 1 , the ratio of the thickness T1 of the first layer 51 to the thickness T2 of the second layer 52 refers to the ratio of the thickness T1 of the first layer 51 to the thickness T2 of the second layer 52 on the same line in the direction perpendicular to the first surface 10a of the light-emitting element 10. In the light-emitting device of the second embodiment and the light-emitting device of the third embodiment described later, when the light source is the light-emitting element 10, the ratio of the thickness T1 of the first layer to the thickness T2 of the second layer refers to the ratio of the thickness T1 of the first layer 51 to the thickness T2 of the second layer 52 on the same line in the direction perpendicular to the first surface 10a of the light-emitting element 10 on the first surface 10a of the light-emitting element 10 facing the substrate 200. When the thickness T1 of the first layer 51 is larger than the thickness T2 of the second layer 52, the light emitted from the light source is easily absorbed by the first layer 51, and the wavelength conversion can be performed efficiently, so that red light with high luminous flux is emitted from the light-emitting device 101, 102, or 103.

[0086] When the thickness Te of the light emitting element is 150 μm and the thickness T2 of the second layer is in the range of 30 μm to 250 μm, the thickness T1 of the first layer may be in the range of 150 μm to 400 μm, in the range of 200 μm to 350 μm, or in the range of 200 μm to 300 μm. When the thickness Te of the light emitting element is 150 μm and the thickness T1 of the first layer is in the range of 150 μm to 400 μm, the thickness T2 of the second layer may be in the range of 50 μm to 200 μm, or in the range of 50 μm to 150 μm. When the thickness Te of the light-emitting element is 150 μm, the total T1+T2 of the thickness T1 of the first layer and the thickness T2 of the second layer may be in the range of greater than 180 μm and less than 650 μm, greater than 200 μm and less than 600 μm, or greater than 230 μm and less than 550 μm.

[0087] The thickness T1 of the first layer may be the same as or smaller than the thickness T2 of the second layer. When the thickness T2 of the second layer is set to 1, the thickness T1 of the first layer may be in the range of 0.1 times or more and 1 times or less, in the range of 0.2 times or more and 0.9 times or less, in the range of 0.3 times or more and 0.8 times or less, in the range of 0.7 times or less, or in the range of 0.6 times or less. When the thickness T1 of the first layer is smaller than the thickness T2 of the second layer, the second layer is used to suppress the intrusion of oxygen and water into the light-emitting device, suppress the degradation of the fluoride phosphor that easily reacts with oxygen and water, and for example, when the light-emitting device is continuously lit for a long time, the reduction in the luminous flux maintenance rate of the light-emitting device can be suppressed.

[0088] When the thickness Te of the light-emitting element is 150 μm, and the thickness T2 of the second layer is in the range of 50 μm to 300 μm, the thickness T1 of the first layer may be in the range of 100 μm to 300 μm, or in the range of 150 μm to 300 μm. When the thickness Te of the light-emitting element is 150 μm, and the thickness T1 of the first layer is in the range of 100 μm to 300 μm, the thickness T2 of the second layer may be in the range of 50 μm to 300 μm, or in the range of 100 μm to 250 μm. When the thickness Te of the light-emitting element is 150 μm, the total thickness T1 of the first layer and the thickness T2 of the second layer (T1+T2) may be in the range of 150 μm to 600 μm, or in the range of 200 μm to 600 μm, or in the range of 230 μm to 550 μm.

[0089] Translucent

[0090] In the light emitting device 101, the second layer 52 is arranged in contact with at least a portion of the first layer 51, and includes a light-transmitting body 90 arranged on the opposite side of the second layer 52 in contact with the first layer 51. When the second layer 52 is arranged in contact with at least a portion of the first layer 51, the wavelength-converted light by the fluoride phosphor 71 contained in the first layer 51 and the light from the light source 10 emitted by passing through the first layer 51 are efficiently converted in wavelength, and red light with high luminous flux is obtained from the light emitting device 101. The light emitting device 101 can suppress the entry of oxygen and water existing outside the light emitting device 101 into the light emitting device 101 by using the light-transmitting body 90 arranged on the opposite side of the second layer 52 in contact with the first layer 51, protect the nitride phosphor 72 contained in the second layer 52, and maintain a high luminous flux of red light. In addition, by including the light-transmitting body 90, the light emitting device 101 can improve the intensity of the light emitting device 101. The thickness of the light-transmitting body is not particularly limited as long as it can suppress the intrusion of oxygen and water into the light-emitting device. For example, it can be set in the range of 30 μm to 300 μm, preferably in the range of 40 μm to 280 μm, and more preferably in the range of 50 μm to 270 μm.

[0091] The light-transmitting body is preferably made of a glass material. Examples of the glass material constituting the light-transmitting body include borosilicate glass, quartz glass, sapphire glass, calcium fluoride glass, aluminoborosilicate glass, oxynitride glass, and chalcogenide glass. When the light-transmitting body is made of a glass material, the intrusion of oxygen and water into the light-emitting device can be further suppressed, and the red light emitted from the second layer will not be hindered, so that the intensity of the light-emitting device can be improved. In the case where the first layer or the second layer is made of a glass material, the light-transmitting body may be made of the same glass material as the second layer, or may be made of a glass material different from the second layer.

[0092] The light-transmitting body and the molded body or the second layer may also be bonded by an adhesive material. As the adhesive material, an adhesive material containing epoxy resin, silicone resin, etc., an organic adhesive material with a high refractive index, an inorganic adhesive material, a low melting point glass, etc. may be used.

[0093] Reflective parts

[0094] The light emitting device 101 preferably includes a reflective member 80 disposed in contact with a portion of the light source 10, a portion of the first layer 51, and a portion of the second layer 52. The reflective member 80 preferably contacts a portion of the light source 10, a portion of the first layer 51, and a portion of the second layer 52, and is disposed from the bottom surface to the inner wall surface of the recess 40r of the molded body 40. The reflective member 80 efficiently reflects the light emitted from the light source 10 and the light wavelength-converted by the first layer 51 and the second layer 52, and can increase the luminous flux of the red light emitted from the light emitting device 101.

[0095] The reflective component preferably contains a reflective material and a resin or glass. As a reflective material, for example, an oxide containing at least one selected from a group consisting of yttrium, zirconium, aluminum and titanium whose reflectivity at a specific wavelength is above a specific value can be cited. For example, an oxide containing at least one selected from a group consisting of yttrium, zirconium, aluminum and titanium whose reflectivity at a specific wavelength is above 50% from a light source having a luminous peak wavelength within a range of above 400nm and below 480nm can be cited. The reflective component may also contain a white pigment whose reflectivity at a specific wavelength is not above a specific value. As a white pigment, one of titanium oxide, zinc oxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, calcium carbonate, calcium hydroxide, calcium silicate, magnesium silicate, barium titanate, barium sulfate, aluminum hydroxide, aluminum oxide and zirconium oxide can be used alone, or two or more of them can be used in combination. The shape of the white pigment is not particularly limited, and it can also be amorphous or broken, but it is preferably spherical from the perspective of fluidity. In addition, the particle size of the white pigment can be cited, for example, a degree of above 0.1μm and below 0.5μm.

[0096] The manufacturing method of the light-emitting device 101 of the first mode preferably includes: placing the light source 10 on the first lead 20 constituting the bottom surface of the recess 40r of the molded body 40; covering at least a portion of the light extraction surface of the light source 10 with a first resin composition containing a first resin and a fluoride phosphor 71, and curing the first resin composition to form a first layer 51; covering at least a portion of the first layer 51 with a second resin composition containing a second resin and a nitride phosphor 72, and curing the second resin composition to form a second layer 52.

[0097] In the process of placing the light source 10 on the molded body 40, the light source 10 is die-bonded with the first lead 20, and the positive and negative electrodes formed on the first surface 10a of the first lead 20 for extracting light and opposite to the second surface 10b are connected to the first lead 20 and the second lead 30 via the wire 60, respectively. With regard to the molded body 40, the first lead 20 and the second lead 30 may be arranged at predetermined positions in the cavity of the resin molding metal mold, and the molding resin may be injected into the cavity and cured to form the molded body 40 having the recess 40r. Alternatively, the molded body 40 in which the first lead 20 and the second lead 30 are integrally molded by resin may be purchased in advance for use. With regard to the reflective component 80, the reflective component may be formed by injecting a resin composition for the reflective component into the recess 40r of the molded body 40 before forming the first layer 51 and the second layer 52. Alternatively, the molded body 40 having the reflective component 80 may be purchased in advance for use.

[0098] In the process of forming the first layer 51, the first resin composition can be dropped using a dispensing machine or the like in such a manner that the first resin composition contacts at least a portion of the light extraction surface of the light source 10 placed in the recess 40r of the molded body 40, and the first resin composition is cured to form the first layer 51 containing the fluoride phosphor 71.

[0099] In the process of forming the second layer 52, the second resin composition may be dripped from the first layer 51 using a dispensing machine or the like in such a manner as to contact at least a portion of the first layer 51, the second resin composition may be cured, and the second layer 52 containing the nitride phosphor 72 may be formed in such a manner as to contact at least a portion of the first layer 51. After the second layer 52 is formed, a light-transmitting body 90 may be arranged on the side of the second layer 52 opposite to the side in contact with the first layer 51. In the case of using an aggregate molded body in which a plurality of molded bodies including a plurality of recesses 40r are integrally molded, a singulation process of cutting the aggregate molded body into individual molded bodies for singulation may also be included. As a method for singulating the aggregate molded body, a method such as cutting based on a wire cutting mold or a cutting saw or cutting based on a laser may be used.

[0100] Figure 2 1 is a schematic cross-sectional view showing a second embodiment of the light emitting device. The light emitting device 102 showing the second embodiment is different from the light emitting device 101 showing the first embodiment in that the light source 10 is the light emitting element and the surface on which the pair of electrodes are formed is flip-chip mounted on the substrate 200, and that a resin molded portion 43 that is integral with the substrate 200 and constitutes the side wall of the recess is provided instead of the molded body 40 in which the first lead and the second lead are integrally molded, but the other aspects are the same.

[0101] substrate

[0102] The substrate 200 carries at least one light source 10 and electrically connects the light emitting device 102 to the outside. The substrate 200 includes a flat support member and a conductor wiring arranged on the surface and / or inside of the support member. The support member of the substrate 200 is formed in a flat plate shape, and the support member may also include a heat dissipation member or a heat dissipation terminal. The support member is preferably formed using an insulating material. As the insulating material constituting the support member, ceramics such as aluminum oxide, aluminum nitride, and mullite, phenol resins, epoxy resins, polyimide resins, bismaleimide triazine resins, and resins such as polyphthalamide can be cited. The substrate 200 can be formed by dripping or flowing the resin into the chamber and curing it. The conductor wiring and the terminal for heat dissipation can be formed using metals such as Cu, Ag, Au, Al, Pt, Ti, W, Pd, Fe, Ni, and their alloys. The conductor wiring can be formed by methods such as electroplating, electroless plating, evaporation, and sputtering.

[0103] As a method for manufacturing the light emitting device 102 of the second embodiment, for example, there can be cited the following method, which includes: flip-chip mounting the light source 10 on the substrate 200 in the concave portion of the resin molded portion 43; arranging the reflective member 81 around the light source 10; arranging the first layer 51 in contact with the reflective member 81; and arranging the second layer 52 on the first layer 51. The reflective member 81 preferably contains a reflective material and a resin or glass like the reflective member 80, and the reflective material can use the same material as the reflective member 80. The reflective member 81 can be formed by dripping a reflective member composition containing a reflective material and a resin or glass around the light source 10 in the concave portion of the resin molded portion 43 and curing the composition.

[0104] When the light source 10 is a light emitting element, the surface 10b on which the positive and negative electrodes are formed may be mounted, for example, face-down, on the conductor wiring of the substrate 200 via a bonding member such as a bump. When the light emitting element is face-down mounted on the substrate 200 as the light source 10, the first surface 10a opposite to the surface 10b on which the pair of electrodes of the light source 10 are formed mainly becomes a light extraction surface.

[0105] The light emitting device 102 preferably carries the upper surface of the substrate 200 other than the part on which the light source 10 flip-chip mounted on the substrate 200 is mounted, at least a part of the light source 10, and at least a part of the first layer 51 are covered by a reflective component 81. The reflective component 81 can supply the third resin composition constituting the reflective component 81 into the recess 43r of the resin molding portion 43, cure the third resin composition and form the reflective component 81. The reflective component 81 can use the same raw materials as the raw materials constituting the reflective component used in the light emitting device 101 of the first embodiment, containing a reflective material or a white pigment, preferably containing a resin. In the case where the flip-chip mounted light source 10 is a light emitting element, the reflective component 81 can also be configured in a manner that covers the entire side surface of the light emitting element, or in a manner that covers a part of the side surface. In the case where the flip-chip mounted light source 10 is a light-emitting element, the reflective component 81 covers a portion of the side surface or the entire side surface of the light-emitting element from the upper surface of the substrate 200 to a height consistent with the upper surface of the resin molded portion 43 constituting the side wall of the recess. When covering the inner surface of the recess of the resin molded portion 43, light will not be extracted from the side surface of the second layer 52 which becomes the light emission surface, so the emission direction of the light will not be scattered, and red light can be emitted from the upper surface of the second layer 52.

[0106] The first layer 51 containing the fluoride phosphor 71 can be formed by using a first resin composition containing the fluoride phosphor 71 and a resin, and curing the first resin composition. The first resin composition is preferably dripped onto the recess 43r of the resin molded portion 43 in a manner in contact with the reflective member 81 and cured. A second resin composition containing a nitride phosphor 72 and a resin is dripped from the first layer 51, and the second resin composition is cured, so that the second layer 52 can be formed in a manner in contact with the first layer 51. The second layer 52 can also be formed by curing the second resin composition separately from the first layer 51 without dripping the second resin composition onto the first layer 51, so that the second layer 51 is in contact with the first layer 51, and the first layer 51 and the second layer 52 are bonded using an adhesive material. The first layer 51 can also be configured so that the fluoride phosphor 71 is present on the side of the deflected light source 10, for example, by centrifugal sedimentation before curing the resin or glass, and then the first resin composition is cured to form the first layer 51. In addition, the second layer 52 may be configured so that the nitride phosphor 72 is present on the side biased toward the first layer 51 by natural sedimentation or centrifugal sedimentation before the resin or glass is cured, and then the second resin composition is cured to form the second layer 52. In the case where the fluoride phosphor 71 or the nitride phosphor 72 is biased, a transparent layer in which the fluoride phosphor 71 or the nitride phosphor 72 is not present may be formed between the first layer 51 and the second layer 52, or a transparent layer in which the nitride phosphor 72 is not present may be formed on the opposite side of the second layer 52 in contact with the first layer 51. When a transparent layer in which the nitride phosphor 72 is not present is formed on the opposite side of the second layer 52 in contact with the first layer 51, the transparent layer can suppress the intrusion of oxygen and water into the light-emitting device 102.

[0107] When the resin molded portion 43 having a plurality of recessed portions 43r is an integrally molded assembly, a singulation step may be included in which the assembly is cut into individual light emitting devices 102 each including at least one light source 10. As a method for singulating the assembly, the same method as the method for singulating the above-mentioned assembly molded body may be used.

[0108] In the light emitting device 102 of the second embodiment, the total thickness T1+T2 of the first layer and the second layer on the same line in the direction perpendicular to the first surface 10a of the light emitting element 10 is preferably greater than the thickness Te of the light emitting element. In the light emitting device 102 of the second embodiment, the total thickness T1+T2 of the first layer and the second layer on the same line in the direction perpendicular to the first surface 10a of the light emitting element 10 is preferably within a range of 1.1 times or more and 3 times or less, more preferably within a range of 1.3 times or more and 2.6 times or less, and further preferably within a range of 1.6 times or more and 2.3 times or less. In the light emitting device 102 of the second embodiment, the thickness T1 of the first layer 51 on the same line in the direction perpendicular to the first surface 10a of the light emitting element 10 may be greater than the thickness T2 of the second layer 52. When the thickness T2 of the second layer 52 is set to 1, the thickness T1 of the first layer 51 may be within a range of 1.1 times or more and 5 times or less, 1.2 times or more and 4.5 times or less, 1.3 times or more and 4 times or less, 3.5 times or less, 3 times or less, or 2 times or less. In the light emitting device 102 of the second embodiment, the thickness T1 of the first layer 51 on the first surface 10a of the light emitting element 10 and on the same line in a direction perpendicular to the first surface 10a of the light emitting element 10 may be the same as or smaller than the thickness T2 of the second layer 52. When the thickness T2 of the second layer 52 is set to 1, the thickness T1 of the first layer 51 may be within a range of 0.1 times or more and 1 times or less, 0.2 times or more and 0.9 times or less, 0.3 times or more and 0.8 times or less, 0.7 times or less, or 0.6 times or less.

[0109] Figure 3 1 is a schematic cross-sectional view showing a third embodiment of the light emitting device. The light emitting device 103 showing the third embodiment is different from the light emitting device 102 showing the second embodiment in that there is no boundary between the first layer 51 and the second layer 52 but an intermediate region 53 and that the reflective component 81 covers a part of the side surface of the light source 10, but the other aspects are the same.

[0110] Middle area

[0111] The first layer 51 and the second layer 52 of the light emitting device 103 are arranged continuously, and an intermediate region 53 containing a fluoride phosphor 71, a nitride phosphor 72, and a resin or glass is provided between the first layer 51 and the second layer 52. With regard to the intermediate region, after a first resin composition containing a fluoride phosphor 71 and a resin or glass and constituting the first layer 51 is arranged around the light source 10, before the first resin composition is cured, a second resin composition containing a nitride phosphor 72 and a resin or glass and constituting the second layer 52 is arranged in a manner such that at least a portion of the second resin composition is continuous with the first resin composition, and then the first resin composition and the second resin composition are cured, thereby the first layer 51 containing a fluoride phosphor 71 and a resin or glass, the intermediate region 53 containing a fluoride phosphor 71, a nitride phosphor 72, and a resin or glass, and the second layer 52 containing a nitride phosphor 72 and a resin or glass are continuously manufactured without boundaries between the respective layers or regions. Compared with the case where the first layer 51 and the second layer 52 have a boundary, the heat from the light source is easily dissipated to the outside when the first layer 51, the intermediate region 53, and the second layer 52 are continuously arranged without any boundary, and the heat dissipation is good.

[0112] Regarding the manufacturing method of the light-emitting device 103, a first resin composition containing a fluoride phosphor 71 and a resin is poured onto the light source 10, and before the first resin composition is cured, a second resin composition containing a nitride phosphor 72 is poured. It can also be configured so that before the second resin composition is poured, the fluoride phosphor 71 in the first resin composition poured onto the light source 10 exists on the side biased toward the light source by natural sedimentation or centrifugal sedimentation. The second resin composition can also be configured so that after being poured onto the first resin composition, the nitride phosphor 72 exists on the side biased toward the first resin composition by natural sedimentation or centrifugal sedimentation. Before the first resin composition is cured, there is no boundary between the first resin composition and the second resin composition, and an intermediate region 53 in which the fluoride phosphor 71 and the nitride phosphor 72 are mixed is formed. At this time, regarding the particle size of the phosphors of the first layer 51 and the second layer 52, it is preferred that the average particle size of the fluoride phosphor 71 contained in the first layer 51 is larger than the average particle size of the nitride phosphor 72 contained in the second layer 52. Thus, when the phosphors are arranged in the first layer 51 and the second layer 52 by natural sedimentation or centrifugal sedimentation, the fluoride phosphor 71 contained in the first layer 51 can be prevented from mixing into the second layer 52 outside the intermediate region 53, and the nitride phosphor 72 contained in the second layer 52 can be prevented from mixing into the first layer 51 outside the intermediate region 53, so that excellent heat dissipation can be obtained while suppressing the reduction of the light flux. When there is no boundary between the first layer 51 and the second layer 52, and the intermediate region 53 containing the fluoride phosphor 71 and the nitride phosphor 72 having better thermal conductivity than resin or glass is formed, the heat dissipation path of the heat passing through the resin or glass with low thermal conductivity becomes shorter than when a transparent layer without the fluoride phosphor 71 and the nitride phosphor 72 is formed between the first layer 51 and the second layer 52, so that the heat dissipation of the heat emitted from the light source 10 is excellent. In the second layer 52, a transparent layer without the nitride phosphor 72 may be formed on the side opposite to the light source 10 side. When a transparent layer in which the nitride phosphor 72 is not present is formed on the side of the second layer 52 opposite to the light source 10 side, the transparent layer can suppress the intrusion of oxygen and water into the light emitting device 103 .

[0113] In the light emitting device 103 of the third embodiment, it is difficult to measure the thickness of the intermediate region 53 alone, and it is also difficult to separately measure the thickness T1 of the first layer 51 and the thickness of the intermediate region 53, and the thickness T2 of the second layer 52 and the thickness of the intermediate region 53. In the light emitting device 103, when the first layer 51, the second layer 52, and the intermediate region 53 are formed, the total thickness of the first layer 51, the second layer 52, and the intermediate region 53 can be measured as the total thickness T1+T2 of the thickness T1 of the first layer 51 and the thickness T2 of the second layer 52. In the light emitting device 103 of the third embodiment, the total thickness T1+T2 of the first layer 51, the intermediate region 53, and the second layer 52 on the same line in a direction perpendicular to the first surface 10a of the light emitting element 10 is preferably greater than the thickness Te of the light emitting element 10. In the light emitting device 103 of the third embodiment, the total thickness T1+T2 of the first layer 51, the intermediate region 53, and the second layer 52 on the first surface 10a of the light emitting element 10 and on the same line in a direction perpendicular to the first surface 10a of the light emitting element 10 is preferably a thickness in the range of 1.1 times or more and 3 times or less, more preferably a thickness in the range of 1.3 times or more and 2.6 times or less, and further preferably a thickness in the range of 1.6 times or more and 2.3 times or less. In the light emitting device 103 of the third embodiment, the thickness Te of the light emitting element 10, the total thickness T1+T2 of the first layer 51, the intermediate region 53, and the second layer 52 is the total thickness T1+T2 of the thickness Te of the light emitting element 10, the first layer 51, the intermediate region 53, and the second layer 52 on the same line in a direction perpendicular to the first surface 10a of the light emitting element 10.

[0114] [Example]

[0115] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples.

[0116] Fluoride complex phosphor 71-1

[0117] As the Mn-activated fluoride complex phosphor 71-1, a phosphor having K2[SiMn 4+ F6] fluoride phosphor. The emission spectrum and reflection spectrum of the fluoride complex phosphor 71-1 were measured by the method described below. 4+F6] The fluoride complex phosphor 71-1 of the composition represented by has a luminescence peak wavelength at 631nm, and the half-peak width of the maximum luminescence peak is 2.6nm. When the luminescence peak wavelength of the excitation light is 450nm, the reflectivity of the fluoride complex phosphor 71-1 is 22.0%. The reflectivity measured according to the reflection spectrum of each phosphor is a reference value. The refractive index of the fluoride complex phosphor 71-1 and 71-2 is 1.36. The refractive index of the fluoride complex phosphor, MGF phosphor, nitride phosphor and silicone resin is a calculated value. The average particle size of the fluoride complex phosphor 71-1 measured by the FSSS method described later is 29.0μm.

[0118] Fluoride complex phosphor 71-2

[0119] As the Mn-activated fluoride complex phosphor 71-2, a phosphor having K2[SiMn 4+ The fluoride phosphor with a composition represented by K2[SiMn 4+ The fluoride complex phosphor 71-2 of the composition represented by F6] has a peak emission wavelength at 631nm, and the half-peak width of the maximum emission peak is 2.6nm. When the peak emission wavelength of the excitation light is 450nm, the reflectivity of the fluoride complex phosphor 71-2 is 12.2%. The average particle size of the fluoride complex phosphor 71-2 measured by the FSSS method is 70.5μm.

[0120] MGF phosphor 71-3

[0121] As the Mn-activated MGF phosphor 71-3, a phosphor having (ij)MgO·(j / 2)M b 2O3·kMgF2·mCaF2·(1-n)GeO2·(n / 2)M c 2O3:zMn 4+ (MGF phosphor 71-3 having a composition represented by (the above formula (II-II)). The emission spectrum and reflectance spectrum of MGF phosphor 71-3 are measured by the method described below. MGF phosphor 71-3 having a composition represented by formula (II-II) has a peak emission wavelength at 670nm, and the half-width of the maximum emission peak is 25nm. When the peak emission wavelength of the excitation light is 450nm, the reflectivity of MGF phosphor 71-3 is about 40%, and the refractive index is 1.70 to 1.81. The average particle size of Mn-activated MGF phosphor 71-3 measured by the FSSS method is 20.5μm.

[0122] Nitride phosphor 72-1

[0123] As the nitride phosphor 72-1, a nitride phosphor having a composition represented by (Ca, Sr, Eu)AlSiN3 is prepared. The luminescence spectrum and reflectance spectrum of the nitride phosphor are measured by the method described later. The nitride phosphor having a composition represented by (Ca, Sr, Eu)AlSiN3 has a luminescence peak wavelength at 635nm, and the half-width of the maximum luminescence peak is 78.9nm. When the luminescence peak wavelength of the excitation light is 450nm, the reflectivity of the nitride phosphor 72-1 is 5.8%. The refractive index of the nitride phosphors 72-1, 72-2, 72-3 and 72-4 is 2.15 to 2.25. The average particle size of the nitride phosphor 72-1 measured by the FSSS method is 14.1μm.

[0124] Nitride phosphor 72-2

[0125] As the nitride phosphor 72-2, a nitride phosphor having a composition represented by (Ca, Sr, Eu)AlSiN3 is prepared. The luminescence spectrum and reflectance spectrum of the nitride phosphor are measured by the method described later. The nitride phosphor 72-2 having a composition represented by (Ca, Sr, Eu)AlSiN3 has a luminescence peak wavelength at 648nm, and the half-width of the maximum luminescence peak is 86.8nm. When the luminescence peak wavelength of the excitation light is 450nm, the reflectivity of the nitride phosphor 72-2 is 7.0%. The average particle size of the nitride phosphor 72-2 measured by the FSSS method is 10.4μm.

[0126] Nitride phosphor 72-3

[0127] As the nitride phosphor 72-3, a nitride phosphor having a composition represented by (Ca, Eu)AlSiN3 is prepared. The luminescence spectrum and reflectance spectrum of the nitride phosphor are measured by the method described later. The nitride phosphor 72-3 having a composition represented by (Ca, Eu)AlSiN3 has a luminescence peak wavelength at 665nm, and the half-width of the maximum luminescence peak is 90.7nm. When the luminescence peak wavelength of the excitation light is 450nm, the reflectivity of the nitride phosphor 72-3 is 6.6%. The average particle size of the nitride phosphor 72-3 measured by the FSSS method is 10.2μm.

[0128] Nitride phosphor 72-4

[0129] As the nitride phosphor 72-4, a nitride phosphor having a composition represented by (Ca, Sr, Eu)AlSiN3 is prepared. The luminescence spectrum and reflectance spectrum of the nitride phosphor are measured by the method described later. The nitride phosphor having a composition represented by (Ca, Sr, Eu)AlSiN3 has a luminescence peak wavelength at 633nm, and the half-peak width of the maximum luminescence peak is 76nm. When the luminescence peak wavelength of the excitation light is 450nm, the reflectivity of the nitride phosphor 72-4 is 5.0%. The average particle size of the nitride phosphor 72-4 measured by the FSSS method is 12.0μm.

[0130] Evaluation of each phosphor

[0131] Luminescence spectrum

[0132] For fluoride complex phosphors, MGF phosphors, and nitride phosphors, a quantum efficiency measuring device (manufactured by Otsuka Electronics Co., Ltd., product name: QE-2000) was used to irradiate the fluoride phosphor or nitride phosphor with light of an excitation wavelength of 450 nm, and the emission spectrum at room temperature (25°C±5°C) was measured. Figure 4 In the expression, K2[SiMn 4+ F6] shows the emission spectrum of the fluoride complex phosphor 71-1 having a composition. Figure 5 Graph (II) shows the emission spectrum of the MGF phosphor 71-3 having the composition represented by formula (II-II). Figure 6 Graph (a) and (b) show the emission spectrum of the nitride phosphor 72-1 having a composition represented by (Ca, Sr, Eu)AlSiN3. Figure 7 Graph (a) and (b) show the emission spectrum of the nitride phosphor 72-3 having a composition represented by (Ca, Eu)AlSiN3.

[0133] Reflectance spectrum

[0134] For fluoride complex phosphors, MGF phosphors, and nitride phosphors, a spectrofluorophotometer (manufactured by Hitachi High-Technologies Co., Ltd., product name: F-4500) was used to irradiate the fluoride phosphor or nitride phosphor, which was a sample, with light from a halogen lamp, which was an excitation light source, at room temperature (25°C ± 5°C), and the wavelengths of the spectrofluorophotometer on the excitation side and the fluorescence side were scanned to measure the reflection spectrum within the wavelength range of 380 nm to 730 nm. As a reference sample, calcium hydrogen phosphate (CaHPO4) was used. The reflectivity of calcium hydrogen phosphate relative to the excitation light with a peak emission wavelength of 450 nm was used as a reference, and the reflectivity of the fluoride complex phosphor, MGF phosphor, or nitride phosphor was used as a relative reflectivity.

[0135] Average particle size

[0136] The average particle size of each phosphor was measured by the FSSS method using Fisher Sub-Sieve Sizer Model 95 (manufactured by Fisher Scientific Co., Ltd.).

[0137] Example 1

[0138] manufacture Figure 2 A light emitting device 102 in the manner shown. As the light source 10, a light emitting element composed of a GaN-based semiconductor having a peak emission wavelength of 450 nm is used. The light emitting device 102 is flip-chip mounted on a substrate 200 by mounting the light emitting element as the light source 10. A first resin composition containing a silicone resin and a fluoride phosphor 71 containing a fluoride complex phosphor 71-1 and not containing an MGF phosphor at a mixing ratio (parts by mass) shown in Table 1 is dripped so as to contact at least a portion of the light source 10, and the first resin composition is cured to form a first layer 51 containing the fluoride phosphor 71. Next, a second resin composition containing a silicone resin and a nitride phosphor 72-1 at a mixing ratio (parts by mass) shown in Table 1 is dripped onto the first layer 51 so as to contact at least a portion of the first layer 51, and the second resin composition is cured to form a second layer 52 containing the nitride phosphor 72. The refractive index of the silicone resin is 1.4 to 1.5.

[0139] Comparative Example 1

[0140] manufacture Fig.14 The light emitting device 104 is similar to the light emitting device 104 in that it includes a fluorescent layer 54 composed of a single layer containing a nitride fluorescent body 72-1. Figure 2 The light emitting device 102 of the embodiment shown in the figure is different. As for the fluorescent layer 54, a resin composition for the fluorescent layer containing a silicone resin and a nitride phosphor 72-1 in the mixing ratio (parts by mass) shown in Table 1 is used, and the resin composition for the fluorescent layer is dripped in a manner that contacts at least a portion of the light source 10, and the resin composition is cured to form the fluorescent layer 54.

[0141] Comparative Example 2

[0142] manufacture Fig.15 The light emitting device 105 is similar to the light emitting device 105 in that it includes a fluorescent layer 55 composed of a single layer containing a fluoride complex fluorescent substance 71-1 and a nitride fluorescent substance 72-1. Figure 2The light emitting device 102 of the embodiment shown in the figure is different. As for the fluorescent layer 55, a resin composition for the fluorescent layer containing silicone resin, fluoride complex phosphor 71-1, and nitride phosphor 72-1 in the mixing ratio (parts by mass) shown in Table 1 is used, and the resin composition for the fluorescent layer is dripped in a manner that contacts at least a part of the light source 10, and the resin composition is cured to form a fluorescent layer 55 containing the fluoride complex phosphor 71-1 and the nitride phosphor 72-1.

[0143] Comparative Example 3

[0144] manufacture Fig.16 The light emitting device 106 is similar to the light emitting device 106 in that it includes a fluorescent layer 56 composed of a single layer containing a fluoride complex fluorescent substance 71-1. Figure 2 As for the fluorescent layer 56, a resin composition for the fluorescent layer containing a silicone resin and a fluoride complex phosphor 71-1 in the mixing ratio (parts by mass) shown in Table 1 is used, and the resin composition for the fluorescent layer is dripped in a manner that contacts at least a portion of the light source 10, and the resin composition is cured to form a fluorescent layer 56 containing the fluoride complex phosphor 71-1.

[0145] Evaluation of light-emitting devices

[0146] Luminescence spectrum

[0147] For the light-emitting devices of each embodiment and comparative example, the light-emitting spectrum indicating the light-emitting intensity relative to the wavelength of each light-emitting device was measured using the same total light-emitting flux measuring device as the measurement of the relative light-emitting flux. The minimum light-emitting intensity and its wavelength in the light-emitting spectrum in the range of 15nm or 30nm from the center to the long wavelength side and the short wavelength side were obtained, taking the maximum light-emitting peak wavelength and the maximum light-emitting peak wavelength in the light-emitting spectrum of each light-emitting device as the center. The light-emitting intensity ratio of the maximum light-emitting peak wavelength and the light-emitting peak wavelength in the light-emitting spectrum of the light-emitting device, with the minimum light-emitting intensity in the light-emitting spectrum in the range of 15nm or 30nm from the center to the long wavelength side and the short wavelength side as the reference light-emitting intensity, was obtained when the reference light-emitting intensity was set to 1. In addition, the dominant wavelength of the light-emitting devices of Examples 1 to 2 and Comparative Examples 1 to 5 was obtained. As for the dominant wavelength, the chromaticity coordinates of white light (x=0.333, y=0.333) and the chromaticity coordinates (x, y) of the light emitted by the light-emitting device in the chromaticity diagram of the CIE1931 color system are connected by a straight line, and the wavelength of the point where the extended line intersects the spectral trajectory is set as the dominant wavelength.

[0148] Chroma(x,y)

[0149] For the light emitting devices of the respective examples and comparative examples, the chromaticity coordinates x and y of the CIE 1931 chromaticity diagram were measured using a light measurement system that combined a multi-channel spectrometer and an integrating sphere.

[0150] Color purity (%)

[0151] The color purity of the light emitting devices of each example and comparative example was measured using a light measuring system combining a multi-channel spectrometer and an integrating sphere. Color purity (%) indicates the concentration of light emitted by a light emitting device.

[0152] Luminous flux (lm)

[0153] The luminous flux of the light emitting device of each example and comparative example was measured using a total luminous flux measuring device using an integrating sphere.

[0154] Table 1 shows the evaluation results of the light emitting devices of Example 1 and Comparative Examples 1 and 2.

[0155]

[0156] In the light emitting device 102 of Example 1, when the reference light emitting intensity is set to 1 in the light emitting spectrum, the light emitting intensity ratio of the maximum light emitting peak wavelength is 8.1, and the light from the light source 10 that is not wavelength-converted by the fluoride phosphor 71 contained in the first layer 51 is efficiently wavelength-converted by the nitride phosphor 72 contained in the second layer 52. Therefore, the blue light emitted from the light source 10 does not substantially escape from the light emitting device 102, and red light with high color purity and high luminous flux is obtained. Compared with the light emitting device 105 of Comparative Example 2 having the fluorescent layer 55 containing the fluoride complex phosphor 71-1 and the nitride phosphor 72-1, the light emitting device 102 of Example 1 has a higher luminous flux. This is because the light-emitting device 102 of Example 1 contains a fluoride complex phosphor 71-1 in the first layer 51 closer to the light source 10, which has a smaller refractive index difference with the resin constituting the first layer 51 and a smaller light reflectivity than the nitride phosphor contained in the second layer 52. Therefore, the blue light from the light source can be efficiently wavelength-converted and the luminous flux can be increased. In addition, the blue light from the light source escaping from the first layer 51 is wavelength-converted by using the nitride phosphor 72-1 contained in the second layer 52, so that red light with high color purity and high luminous flux can be obtained.

[0157] Figure 8 and 9 The light emission spectrum of the light emitting device of Example 1 within the wavelength range of 600 nm to 660 nm is shown. Fig.10The light emission spectrum of the light emitting device of Example 1 in the wavelength range of 400 nm to 500 nm is shown. In the light emission spectrum of the light emitting device of Example 1, the light emission peak of the light source is smaller than the maximum light emission peak. Figure 8 and 9 The light emitting spectrum having the maximum light emitting peak of the light emitting device of Example 1 is shown. Figure 8 and 9 In the emission spectrum of the light-emitting device of Example 1 shown, the maximum emission peak wavelength is 631nm, and the wavelength of the minimum emission intensity in the range from 631nm to 15nm on the long wavelength side and the short wavelength side, that is, in the range of 616nm to 646nm, is 642.1nm. The minimum emission intensity in the range of 616nm to 646nm is set as the reference emission intensity, and the reference emission intensity is set to 1, and the emission intensity ratio of the maximum emission peak wavelength of the above-mentioned light source and the emission intensity ratio of the maximum emission peak wavelength of the light-emitting device are obtained. When the reference emission intensity in the emission spectrum of the light-emitting device is set to 1, the emission intensity ratio of the maximum emission peak wavelength is 8.1 as described above. Fig.10 The luminous spectrum with the maximum luminous peak of the light source of the luminous device of Example 1 is shown. In the luminous spectrum of the luminous device, the luminous peak wavelength of the light source is 441.7nm. When the reference luminous intensity in the luminous spectrum of the luminous device is set to 1, the luminous intensity ratio of the maximum luminous peak wavelength of the light source is 0.017.

[0158] Compared with the light emitting device 104 of Comparative Example 1 having the fluorescent layer 54 containing the nitride phosphor 72-1 and not containing the fluoride complex phosphor 71-1, the light emitting device 105 of Comparative Example 2 has a higher luminous flux due to the fluorescent layer 55 containing the nitride phosphor 72-1 and the fluoride complex phosphor 71-1. On the other hand, the light emitting device 106 of Comparative Example 3 has the fluorescent layer 56 containing the fluoride complex phosphor 71-1 and not containing the nitride phosphor 72-1. Therefore, the main wavelength cannot be measured by using only the blue light emitted from the light source that is not completely absorbed by the fluoride complex phosphor 71-1, and the light emitting device does not emit red light.

[0159] Example 2

[0160] The light emitting device 102 of Example 2 is formed in the same manner as in Example 1, except that the nitride phosphor 72 - 2 is used as the nitride phosphor 72 contained in the second layer 52 .

[0161] Comparative Example 4

[0162] The light-emitting device 104 of Comparative Example 4 is formed in the same manner as Comparative Example 1, except that the nitride phosphor 72-2 is used as the nitride phosphor and a resin composition for a fluorescent layer containing the nitride phosphor 72-2 in the mixing ratio (parts by mass) shown in Table 2 is used.

[0163] Comparative Example 5

[0164] The light-emitting device 105 of Comparative Example 5 is formed in the same manner as Comparative Example 2, except that the nitride phosphor 72-2 is used as the nitride phosphor and a resin composition for a fluorescent layer containing the nitride phosphor 72-2 in the mixing ratio (mass parts) shown in Table 2 is used.

[0165] Table 2 shows the evaluation results of the light emitting devices of Example 2 and Comparative Examples 4 and 5 measured by the above-mentioned evaluation method.

[0166]

[0167] In the emission spectrum of the light emitting device 102 of Example 2, when the reference emission intensity is set to 1, the emission intensity ratio of the maximum emission peak wavelength is 7.6, and the emission intensity ratio of the maximum emission peak wavelength of the light source 10 is 0.014, so the blue light of the light source 10 does not escape from the light emitting device 102, the color purity is substantially the same as that of Comparative Examples 4 and 5, and the luminous flux becomes higher. In the light emitting device 102 of Example 2, the light from the light source 10 that is not wavelength-converted by the fluoride complex phosphor 71-1 contained in the first layer 51 is efficiently wavelength-converted by the nitride phosphor 72-2 contained in the second layer 52, so the blue light of the light source does not escape from the light emitting device 102, and red emission with a high luminous flux is obtained.

[0168] Embodiments 3 to 7

[0169] The light-emitting devices 102 of Examples 3 to 7 were formed in the same manner as in Example 1, except that the fluoride complex phosphor 71-2 was used as the fluoride phosphor contained in the first layer 51 and the fluoride complex phosphor 72-1 was used as the nitride phosphor contained in the second layer 52 in the mixing ratio shown in Table 3.

[0170] Table 3 shows the evaluation results of the light-emitting devices of Examples 3 to 7 measured by the above-mentioned evaluation method.

[0171]

[0172] In the light-emitting devices 102 of Examples 3 to 7, as the mixing ratio of the fluoride complex phosphor 71-2 contained in the first layer 51 increases, the luminous intensity ratio of the maximum luminous peak wavelength when the reference luminous intensity is set to 1 in the luminous spectrum of the light-emitting device 102 increases, and the luminous intensity ratio of the luminous peak wavelength of the light source decreases. According to this result, as the mixing ratio of the fluoride complex phosphor 71-1 contained in the first layer 51 increases, the blue light emitted from the light source 10 does not escape from the light-emitting device 102, and red light with high color purity and high luminous flux is obtained.

[0173] Embodiments 8 to 12

[0174] The light-emitting devices 102 of Examples 8 to 12 are formed in the same manner as in Example 1, except that the fluoride complex phosphor 71-2 is used as the fluoride phosphor 71 contained in the first layer 51 and the nitride phosphor 72-2 is used as the nitride phosphor 72 contained in the second layer 52 in the mixing ratio shown in Table 4.

[0175] Table 4 shows the evaluation results of the light-emitting devices of Examples 8 to 12 measured by the above-mentioned evaluation method.

[0176]

[0177] In the light-emitting devices 102 of Examples 8 to 12, as the mixing ratio of the fluoride complex phosphor 71-2 contained in the first layer 51 increases, the luminous intensity ratio of the maximum luminous peak wavelength when the reference luminous intensity in the luminous spectrum of the light-emitting device 102 is set to 1 increases, and the luminous intensity ratio of the luminous peak wavelength of the light source decreases. According to this result, as the mixing ratio of the fluoride complex phosphor 71 contained in the first layer 51 increases, the blue light emitted from the light source 10 does not escape from the light-emitting device 102, and red light with high color purity and high luminous flux is obtained.

[0178] Example 13

[0179] The light-emitting device 102 of Example 13 is formed in the same manner as in Example 1, except that the MGF phosphor 71-3 is used instead of the fluoride complex phosphor 71-1, and a first resin composition containing the MGF phosphor 71-3 and the nitride phosphor 72-3 in the mixing ratio (parts by mass) shown in Table 5 is used.

[0180] Comparative Example 6

[0181] The light-emitting device 104 of Comparative Example 6 was formed in the same manner as Comparative Example 1, except that a resin composition for a fluorescent layer containing a nitride phosphor 72-3 having a composition represented by (Ca, Eu)AlSiN3 in the mixing ratio (parts by mass) shown in Table 5 was used.

[0182] Table 5 shows the evaluation results of the light-emitting devices of Example 13 and Comparative Example 6.

[0183]

[0184] In the light-emitting device 102 of Example 13, when the reference light-emitting intensity in the light-emitting spectrum is set to 1, the light-emitting intensity ratio of the maximum light-emitting peak wavelength is 3.6, and the blue light emitted from the light source 10 does not substantially escape from the light-emitting device 102, and a red light emission with high color purity and high luminous flux maintained substantially unchanged from that of Comparative Example 6 is obtained. As the main wavelength of the red light emitted from the light-emitting device moves toward the long wavelength side, there is a tendency that the luminous efficiency moves away from the wavelength of 555nm that is easy to focus on the human eye, the visibility becomes lower, and the luminous flux decreases. The main wavelength of the light-emitting device of Example 13 is 636.2nm, and the main wavelength is shifted to the long wavelength side by about 5nm compared with the light-emitting device 104 of Comparative Example 6. Even if the main wavelength of the light-emitting device of Example 13 moves to the long wavelength side, it maintains a slightly higher luminous flux than the light-emitting device of Comparative Example 6, and obtains red light emission with a high luminous flux maintained.

[0185] In the emission spectrum of the light emitting device 104 of Comparative Example 6, when the reference emission intensity is set to 1, the emission intensity ratio of the maximum emission peak wavelength is as low as 1.7, and the luminous flux is slightly lower than that of Example 13.

[0186] Fig.11 The light emission spectrum of the light emitting device of Example 13 within the wavelength range of 600 nm to 800 nm is shown. Fig.12 The light emission spectrum of the light emitting device of Example 13 in the wavelength range of 400 nm to 800 nm is shown. In the light emission spectrum of the light emitting device of Example 13, the light emission peak of the light source is smaller than the maximum light emission peak, so Fig.11 The light emitting spectrum with the maximum light emitting peak of the light emitting device of Example 13 is shown. Fig.12 In the luminous spectrum of the light-emitting device of Example 13 shown, the maximum luminous peak wavelength is 659.9nm, which means that the wavelength with the minimum luminous intensity within the range from 659.9nm to 30nm on the long wavelength side and the short wavelength side, that is, above 629.9nm and below 680.9nm, is 630.2nm. The reference luminous intensity is set to 1, and the luminous intensity ratio of the maximum luminous peak wavelength of the above-mentioned light source and the luminous intensity ratio of the maximum luminous peak wavelength of the light-emitting device are obtained. The luminous intensity ratio of the maximum luminous peak wavelength when the reference luminous intensity in the luminous spectrum of the light-emitting device is set to 1 is 3.6 as described above. In the luminous spectrum of the light-emitting device, the luminous peak wavelength of the light source is 443.4nm. Fig.12The light emission spectrum having the maximum light emission peak of the light source of the light emitting device of Example 13 is shown. The light emission intensity ratio of the maximum light emission peak wavelength of the light source when the reference light emission intensity in the light emission spectrum of the light emitting device is 1 is 0.007.

[0187] Embodiment 14

[0188] manufacture Figure 2 A light emitting device 102 in the manner shown. As the light source 10, a light emitting element composed of a GaN-based semiconductor having a peak emission wavelength of 450 nm is used. The light emitting device 102 flips the light emitting element as the light source 10 onto the substrate 200. A first resin composition containing a silicone resin and a fluoride phosphor 71 is prepared, wherein the fluoride phosphor 71 contains a fluoride complex phosphor 71-1 and does not contain an MGF phosphor. The first resin composition contains 150 parts by mass of the fluoride complex phosphor 71-1 relative to 100 parts by mass of the silicone resin. The first resin composition is dripped in a manner contacting at least a portion of the light source 10, and the first resin composition is cured to form a first layer 51 containing the fluoride phosphor 71. Next, a second resin composition containing a silicone resin and a nitride phosphor 72-4 is prepared. The second resin composition contains 100 parts by mass of the nitride phosphor 72-4 relative to 100 parts by mass of the silicone resin. The second resin composition is dripped onto the first layer 51 in a manner that contacts at least a portion of the first layer 51, and the second resin composition is cured to form the second layer 52 containing the nitride phosphor 72. The refractive index of the silicone resin is 1.4 to 1.5. In the obtained light-emitting device 102, the fluoride phosphor 71 is present on the side of the light-emitting element 10 in the first layer 51 by centrifugal sedimentation, and a transparent layer containing no fluoride phosphor 71 or nitride phosphor 72 is formed between the first layer 51 and the second layer 52. In the cross section of the obtained light-emitting device 102, the thickness Te of the light-emitting element 10 measured by the method described later is 134 μm, the thickness T1 of the first layer 51 on the first surface 10a of the light-emitting element 10 and on the same line in a direction perpendicular to the first surface 10a of the light-emitting element 10 is 76 μm, and the thickness T2 of the second layer 52 is 226 μm. The transparent layer formed between the first layer 51 and the second layer 52 is included in the first layer 51 , and the thickness of the transparent layer alone cannot be measured.

[0189] Embodiment 15

[0190] manufacture Figure 3A light emitting device 103 in the manner shown. The light source 10 uses the same light emitting element as in Example 14. The light emitting device 103 is flip-chip mounted on a substrate 200 by mounting the light emitting element as the light source 10. A first resin composition containing a silicone resin and a fluoride phosphor 71 is prepared, wherein the fluoride phosphor 71 contains a fluoride complex phosphor 71-1 and does not contain an MGF phosphor. The first resin composition contains 150 parts by mass of the fluoride complex phosphor 71-1 relative to 100 parts by mass of the silicone resin. In addition, a second resin composition containing a silicone resin and a nitride phosphor 72-2 is prepared. The second resin composition contains 35 parts by mass of the nitride phosphor 72-2 and 35 parts by mass of the nitride phosphor 72-4 relative to 100 parts by mass of the silicone resin. In order to adjust the chromaticity of the light emitted from the light emitting device 103, two types of nitride phosphors 72-2 and nitride phosphors 72-4 having different compositions of the phosphors are used as the nitride phosphor 72 contained in the second resin composition. The first resin composition is dripped in a manner contacting at least a portion of the light source 10, and the first resin composition is cured to form a first layer 51 containing a fluoride phosphor 71. Then, the second resin composition is dripped onto the first layer 51 in a manner contacting at least a portion of the first layer 51, and the second resin composition is cured to form a second layer 52 containing a nitride phosphor 72. The obtained light-emitting device 103 contains: the first layer 51 containing the fluoride phosphor 71, the intermediate region 53 where the fluoride phosphor 71 and the nitride phosphor 72 are mixed, and the second layer 52 containing the nitride phosphor 72. The first layer 51, the intermediate region 53, and the second layer 52 are continuous without boundaries between the respective layers or regions. In the cross section of the obtained light-emitting device 103, the thickness Te of the light-emitting element 10 measured by the method described later is 137 μm, and the total thickness T1+T2 of the first layer 51, the second layer 52, and the intermediate region 53 on the first surface 10a of the light-emitting element 10 and on the same line in a direction perpendicular to the first surface 10a of the light-emitting element 10 is 301 μm. In the obtained light-emitting device 103, the first layer 51, the intermediate region 53, and the second layer 52 are continuously formed without boundaries, so the thickness T1 of the first layer 51 and the thickness T2 of the second layer 52 cannot be measured separately.

[0191] Thickness of the light emitting element, the first layer, the second layer and the intermediate region

[0192] Using a scanning electron microscope (SEM), cross-sectional SEM photographs of the light-emitting devices of Examples 14 and 15 were obtained. In the cross-sectional SEM photographs, the thickness between the first surface 10a of the light source 10 mounted on the substrate 200 and the other second surface 10b opposite thereto was measured as the thickness Te of the light-emitting element 10. In addition, on the first surface 10a of the light-emitting element 10 and on the same line in a direction perpendicular to the first surface 10a of the light-emitting element 10, the total thickness T1+T2 of the first layer 51 and the second layer 52 was measured.

[0193] The evaluation results of the light-emitting devices of Example 14 and Example 15 are shown in Table 6.

[0194]

[0195] In the luminous spectra of the light-emitting device 102 of Example 14 and the light-emitting device 103 of Example 15, when the reference luminous intensity is set to 1, the luminous intensity ratio of the maximum luminous peak wavelength is 7.4 or 7.8, and the blue light emitted from the light source 10 will not substantially escape from the light-emitting device 102 or the light-emitting device 103, thereby obtaining red luminescence with high color purity and high luminous flux.

[0196] Reliability evaluation (relative luminous flux after continuous lighting)

[0197] The light-emitting devices of Examples 14 and 15 were placed in a high-temperature tank at a temperature of 85°C and a humidity of 85%, and were continuously illuminated at 350 mA. The luminous flux was measured at each elapsed time using a total luminous flux measuring device using an integrating sphere. The luminous flux of the initial light-emitting device illuminated at 350 mA before being placed in the high-temperature tank was set to 100%, and the luminous flux at each elapsed time from the initial was expressed as a relative value. In addition, the relative value of the luminous flux of the light-emitting device after 1018 hours relative to the luminous flux of the initial light-emitting device of 100% was calculated as the luminous flux maintenance rate. The results are presented in Fig.13 Indicated in.

[0198] The luminous flux maintenance rate of the light emitting device of Example 14 is 42.8%, and the luminous flux maintenance rate of the light emitting device of Example 15 is 72.0%. Fig.13As shown, the light-emitting device of Example 15 forms an intermediate region between the first layer and the second layer where the fluoride complex phosphor 71-1, the nitride phosphor 72-4, and the nitride phosphor 72-2 are mixed. The first layer, the intermediate region, and the second layer are continuously arranged without any boundary. Therefore, it is believed that the heat from the light source is easily dissipated to the outside, the heat dissipation is good, and the luminous flux maintenance rate is increased. The light-emitting device of Example 15 has an intermediate region between the first layer and the second layer where the fluoride complex phosphor 71-1, the nitride phosphor 72-4, and the nitride phosphor 72-2 are mixed. Therefore, even when continuously lit at a high temperature, the durability of the light-emitting device is improved and the luminous flux maintenance rate is improved. The light-emitting device of Example 14 has a transparent layer without any phosphor formed between the first layer and the second layer. Therefore, compared with the light-emitting device of Example 15 having an intermediate region between the first layer and the second layer, the luminous flux maintenance rate is lower.

[0199] Industrial Applicability

[0200] The light emitting device disclosed herein can be applied to traffic lights, illuminated switches, various sensors, various indicators, small flashlights, and the like.

[0201] Description of Reference Numerals

[0202] 10: light source, 10a: first surface, 10b: second surface, 20: first lead, 30: second lead, 40: molded body, 40r: recess, 42: resin portion, 43: resin molded portion, 43r: recess, 50: fluorescent component, 51: first layer, 52: second layer, 53: intermediate area, 54, 55, 56: fluorescent layer, 60: wire, 70: phosphor, 71: fluoride phosphor, 72: nitride phosphor, 80, 81: reflective component, 90: light-transmitting body, 101, 102, 103, 104, 105, 106: light-emitting device, 200: substrate.

Claims

1. A light emitting device for emitting red light, characterized in that: include: A light source, which is a semiconductor light emitting element; a first layer covering at least a portion of the light source and containing a fluoride phosphor including at least one of a fluoride complex phosphor activated by manganese and a fluorogermanate phosphor activated by manganese for converting the wavelength of light emitted from the light source; a second layer covering at least a portion of the first layer and containing a nitride phosphor that converts the wavelength of light emitted from the light source and / or the first layer, and the second layer further contains glass or resin, wherein the content of the nitride phosphor is within a range of 20 parts by mass or more and 200 parts by mass or less relative to 100 parts by mass of the glass or resin; In the case where the fluoride complex phosphor is contained and the fluorogermanate phosphor is not contained, the maximum emission peak wavelength of the light-emitting device in the emission spectrum of the light-emitting device is set as the center, and the minimum emission intensity in the emission spectrum within the range of 15 nm from the center to the long wavelength side and the short wavelength side is set as the reference emission intensity, In the case of containing the fluorogermanate phosphor, the maximum emission peak wavelength of the light-emitting device in the emission spectrum of the light-emitting device is set as the center, and the minimum emission intensity in the emission spectrum within the range of 30 nm from the center to the long wavelength side and the short wavelength side is set as the reference emission intensity, When the reference luminous intensity is set to 1, the luminous intensity ratio of the maximum luminous peak wavelength of the light source exceeds 0 and is within the range of 0.1 or less, and the luminous intensity ratio of the maximum luminous peak wavelength of the light emitting device is greater than 3.0 and less than 12.

0.

2. The light emitting device according to claim 1, wherein: The fluoride complex phosphor has a composition represented by the following formula (I): <h2 style=";text-align:left;direction:ltr">A2[M<h2 style=";text-align:left;direction:ltr"> a <h2 style=";text-align:left;direction:ltr"> 1-a <h2 style=";text-align:left;direction:ltr"> Mn<h2 style=";text-align:left;direction:ltr"> 4+ <h2 style=";text-align:left;direction:ltr"> a <h2 style=";text-align:left;direction:ltr"> F6](I) In formula (I), A is an alkali metal element and NH4 + At least one element or ion selected from the group consisting of a is at least one element selected from the group consisting of Group IVB elements and Group VIA elements of the periodic table, and a is a number satisfying 0<a<0.

2.

3. The light emitting device according to claim 1, wherein: The fluorogermanate phosphor has a composition represented by any one of the following formulas (II-I) and (II-II): 3.5MgO·0.5MgF2·GeO2: Mn(II-I) (i-j)MgO·(j / 2)M b 2O3·kMgF2·mCaF2·(1-n)GeO2·(n / 2)M c 2O3:zMn 4+ (II-II) In formula (II-II), M b is at least one element selected from the group consisting of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, and M c is at least one element selected from the group consisting of Al, Ga and In, and i, j, k, m, n and z are numbers satisfying 2≦i≦4, 0≦j<0.5, 0<k<1.5, 0≦m<1.5, 0<n<0.5, and 0<z<0.05, respectively.

4. The light emitting device according to claim 1, wherein: The nitride phosphor is at least one selected from nitride phosphors containing at least one of calcium and strontium and silicon and aluminum in their composition and activated by europium.

5. The light emitting device according to claim 1, wherein: The nitride phosphor has a composition represented by the following formula (III): (That 1-s-t Sr. s I t ) x the u And v N w (III) In formula (III), s, t, u, v, w and x are numbers that satisfy 0≦s<1, 0<t<1.0, 0<s+t<1.0, 0.8≦x≦1.0, 0.8≦u≦1.2, 0.8≦v≦1.2, 1.9≦u+v≦2.1, and 2.5≦w≦3.5, respectively.

6. The light emitting device according to claim 1, wherein: The light source has a light emission peak wavelength in a range of 400 nm to 480 nm.

7. The light emitting device according to claim 1, wherein: The light source is a GaN-based semiconductor light-emitting element.

8. The light emitting device according to claim 1, wherein: The first layer and the second layer contain resin or glass.

9. The light emitting device according to claim 8, wherein: The resin is at least one selected from the group consisting of silicone resin, modified silicone resin, epoxy resin, and modified epoxy resin.

10. The light emitting device according to claim 1, wherein: The second layer is continuously arranged with the first layer, and contains an intermediate region between the first layer and the second layer. The intermediate region contains the fluoride phosphor and the nitride phosphor, and the intermediate region further contains resin or glass.

11. The light emitting device according to claim 1, wherein: The second layer is arranged so as to be in contact with at least a portion of the first layer, and includes a light-transmitting body arranged on the side of the second layer opposite to the side in contact with the first layer.

12. The light emitting device according to claim 11, wherein: The light-transmitting body is made of glass material.

13. The light emitting device according to claim 1, wherein: A reflecting member is included and is arranged so as to be in contact with a part of the light source, the first layer, or a part of the second layer.

14. The light emitting device according to claim 1, wherein: The first layer includes the fluoride phosphor and glass or resin, and the content of the fluoride phosphor is in a range of 20 parts by mass or more and 200 parts by mass or less relative to 100 parts by mass of the glass or resin.

15. The light emitting device according to claim 1, wherein: In the first layer, the content of the fluoride phosphor is in a range of 150 parts by mass or more and 200 parts by mass or less relative to 100 parts by mass of the glass or the resin.

16. The light emitting device according to claim 2, wherein: The fluoride complex phosphor is Mn-activated fluoride complex phosphor particles, and the average particle size of the Mn-activated fluoride complex phosphor particles is within a range of 10 μm to 90 μm.

17. The light emitting device according to claim 1, wherein: In the second layer, the content of the nitride phosphor is in a range of 100 parts by mass or more and 200 parts by mass or less relative to 100 parts by mass of the glass or the resin.

18. The light emitting device according to claim 1, wherein: The nitride phosphor is a particle, and an average particle size of the nitride phosphor is within a range of 5 μm to 50 μm.

19. The light emitting device according to claim 1, wherein: The light source is a semiconductor light emitting element, and a total thickness of a thickness (T1) of the first layer and a thickness (T2) of the second layer is larger than a thickness (Te) of the semiconductor light emitting element.

20. The light emitting device according to claim 1, wherein: The light source is a semiconductor light emitting element, and the total of the thickness (T1) of the first layer and the thickness (T2) of the second layer is within a range of 1.1 to 3 times the thickness (Te) of the semiconductor light emitting element.

21. The light emitting device according to claim 1, wherein: When the thickness ( T2 ) of the second layer is set to 1, the thickness ( T1 ) of the first layer is 1.1 times or more and 5 times or less of the thickness ( T2 ) of the second layer.

22. The light emitting device according to claim 1, wherein: When the thickness ( T2 ) of the second layer is set to 1, the thickness ( T1 ) of the first layer is greater than or equal to 0.1 times and less than or equal to 1 times the thickness ( T2 ) of the second layer.

23. The light emitting device according to claim 1, wherein: The light source is a semiconductor light emitting element, and when the thickness of the semiconductor light emitting element is 150 μm, the total thickness of the first layer ( T1 ) and the thickness of the second layer ( T2 ) is within a range of 165 μm to 450 μm.

24. The light emitting device according to claim 1, wherein: The light source is a semiconductor light emitting element, and when the thickness of the semiconductor light emitting element is 150 μm, and the thickness (T2) of the second layer is in the range of greater than 30 μm and less than 250 μm, the thickness (T1) of the first layer is in the range of greater than 150 μm and less than 450 μm.

25. The light emitting device according to claim 1, wherein: The light source is a semiconductor light emitting element, and when the thickness of the semiconductor light emitting element is 150 μm, the total thickness of the first layer ( T1 ) and the thickness of the second layer ( T2 ) is within a range of 180 μm to 650 μm.

26. The light emitting device according to claim 1, wherein: The light source is a semiconductor light emitting element, and when the thickness of the semiconductor light emitting element is 150 μm, and when the thickness (T2) of the second layer is in the range of greater than 50 μm and less than 300 μm, the thickness (T1) of the first layer is in the range of greater than 100 μm and less than 300 μm.

27. The light emitting device according to claim 1, wherein: The light source is a semiconductor light emitting element, and when the thickness of the semiconductor light emitting element is 150 μm, the total thickness of the first layer ( T1 ) and the thickness of the second layer ( T2 ) is within a range of 150 μm to 600 μm.

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