JP7060816B2 - Light emitting device - Google Patents

Description

The present invention relates to a light emitting device.

A light emitting device that emits white light by combining a light emitting diode (Light Emitting Diode, hereinafter also referred to as “LED”) and a phosphor has been developed. In these light emitting devices, a desired light emitting color such as white light or red light can be obtained by the principle of color mixing of light. These light emitting devices are used in a wide range of fields such as general lighting, in-vehicle lighting, displays, and liquid crystal backlights. The light emitting device is required to be capable of obtaining mixed color light having good color purity. A light emitting device having a narrow half width of a light emitting peak in the light emitting spectrum of the light emitting device is known. The full width at half maximum refers to the full width at half maximum (FWHM) of the emission peak in the emission spectrum, and refers to the wavelength width of the emission peak indicating a value of 50% of the maximum value of the emission peak in the emission spectrum.

For example, Patent Document 1 includes an LED element that emits blue light and a fluorescent substance that emits yellow light and / or green light by wavelength-converting the light emitted by the LED element, and the half-price range of this fluorescent body is narrow. A light emitting device is disclosed in which a fluoride phosphor activated with manganese is used, the amount of the fluoride phosphor used is reduced, and white light is emitted by color mixing of light.

Japanese Unexamined Patent Publication No. 2012-104814

One aspect of the present invention is to provide a light emitting device that emits red light having excellent luminous flux and color purity.

A first aspect of the present invention is a light source, a manganese-activated fluoride complex phosphor that covers at least a portion of the light source and wavelength-converts the light emitted from the light source, and a manganese-activated fluorojar money. A nitride that covers at least a part of the first layer and the first layer containing a fluoride phosphor containing at least one of the phosphors, and wavelength-converts the light emitted from the light source and / or the first layer. With a second layer containing a phosphor, including the fluoride complex phosphor, and not including the fluorogermanate phosphor, centered on the maximum emission peak wavelength in the emission spectrum of the light emitting device. The smallest emission intensity in the emission spectrum within the range of 15 nm for each of the long wavelength side and the short wavelength side from the center is set as the reference emission intensity, and when the fluorogermanate phosphor is contained, the maximum emission intensity in the emission spectrum of the light emitting device. The reference emission intensity is the smallest 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, respectively, with the emission peak wavelength as the center. It is a light emitting device that emits red light, wherein the emission intensity ratio of the maximum emission peak wavelength is in the range of more than 0 and 0.1 or less, and the emission intensity ratio of the maximum emission peak wavelength is more than 2.8.

According to one aspect of the present invention, it is possible to provide a light emitting device that emits red light having excellent luminous flux and color purity.

It is a schematic cross-sectional view which shows the 1st aspect of a light emitting device. It is a schematic cross-sectional view which shows the thickness of a light emitting element, the thickness of a 1st layer, and the thickness of a 2nd layer in the 1st aspect of a light emitting device. It is a schematic cross-sectional view which shows the 2nd aspect of a light emitting device. It is a schematic cross-sectional view which shows the 3rd aspect of a light emitting device. It is a figure which shows the emission spectrum of a fluoride complex phosphor. It is a figure which shows the emission spectrum of a fluorogermanate phosphor. It is a figure which shows the emission spectrum of the nitride phosphor 72-1 ((Ca, Sr, Eu) AlSiN ₃ ). It is a figure which shows the emission spectrum of the nitride phosphor 72-3 ((Ca, Eu) AlSiN ₃ ). It is a figure which shows the emission spectrum in the wavelength range of 600 nm or more and 660 nm or less of the light emitting apparatus which concerns on Example 1. FIG. It is a figure which shows the maximum emission peak wavelength and the reference emission intensity in the emission spectrum of the light emitting apparatus which concerns on Example 1. FIG. It is a figure which shows the emission spectrum in the wavelength range of 400 nm or more and 500 nm or less of the light emitting apparatus which concerns on Example 1. FIG. It is a figure which shows the maximum emission peak wavelength and the reference emission intensity in the emission spectrum of the light emitting apparatus which concerns on Example 13. It is a figure which shows the emission spectrum in the wavelength range of 400 nm or more and 500 nm or less of the light emitting apparatus which concerns on Example 13. It is a graph which shows the relative luminous flux after continuous lighting from the initial stage of the light emitting device which concerns on Examples 14 and 15. It is a schematic cross-sectional view which shows the aspect of the light emitting device which concerns on Comparative Example 1. FIG. It is a schematic cross-sectional view which shows the aspect of the light emitting device which concerns on Comparative Example 2. FIG. It is a schematic cross-sectional view which shows the aspect of the light emitting device which concerns on Comparative Example 3. FIG.

Hereinafter, the light emitting device according to the present invention will be described based on one embodiment. However, the embodiments shown below are examples for embodying the technical idea of the present invention, and the present invention is not limited to the following light emitting devices. 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, and the like follow JIS Z8110.

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

The light emitting device 101 includes a light source 10, a first layer 51 including a fluoride phosphor 71 that covers at least a part of the light source 10 and converts the wavelength of the light emitted from the light source 10, and at least a part of the first layer 51. Includes a second layer 52 containing a nitride phosphor 72 that covers and / or wavelength-converts the light emitted from the light source 10 and / or the first layer 51. The first layer 51 and the second layer 52 constitute the fluorescent member 50.

The light emitting device 101 includes a molded body 40. The molded body 40 is formed by integrally molding a first lead 20, a second lead 30, and a resin portion 42 containing a thermoplastic resin or a thermosetting resin and forming a side wall of the molded body 40. Is. 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 have a first lead 20, a second lead 30, and a wire 60, respectively. It is electrically connected via. The light emitting device 101 can emit light by receiving an electric power supply from the outside via the first lead 20 and the second lead 30.

Light source The light source 10 preferably uses a semiconductor light emitting device, and more preferably a GaN-based semiconductor light emitting device. By using a GaN-based semiconductor light emitting device as a light source, it is possible to obtain a light emitting device having high efficiency, high linearity with respect to an input, and strong against mechanical impact. For example, a GaN-based semiconductor light emitting device using a nitride-based semiconductor (In _x Al _Y Ga _1-XY N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) can be used.
The emission peak wavelength of the light source 10 is preferably in the range of 400 nm or more and 480 nm or less, and more preferably in the range of 420 nm or more and 460 nm or less.
When the light source 10 is a light emitting element, the second surface 10b facing the first surface 10a on which the 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 faces up. When mounted, the first surface 10a on which the pair of electrodes of the light source 10 is formed is mainly the light extraction surface.

The first layer 51 covers at least a part 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 wavelength-converts the light emitted from the light source 10. The first layer 51 may contain a phosphor other than the fluoride phosphor 71, which converts the light from the light source 10 into wavelength and emits red light. The first layer 51 covers at least a part of the light extraction surface of the light source 10. The first layer 51 may be arranged so as to cover the entire surface of the light extraction surface of the light source 10, or may be arranged so as to cover a part of the light extraction surface of the light source 10. The first layer 51 is preferably arranged so as to be in contact with at least a part of the light source 10. When the first layer 51 is arranged so as to be in contact with at least a part of the light source 10, the light emitted from the light source 10 is more than when the first layer 51 is arranged at a distance from the light source 10. Can be easily absorbed, the wavelength can be converted efficiently, and red light emission with an improved luminous flux can be obtained. The fluoride phosphor 71 contained in the first layer 51 is a manganese-activated fluoride complex fluorescent substance (also referred to as “Mn-activated fluoride complex fluorescent substance”) and a manganese-activated fluorogermanate phosphor. (Also referred to as "Mn-activated MGF fluorophore"). The first layer 51 may contain a Mn-activated fluoride complex phosphor and may not contain a Mn-activated MGF phosphor. The first layer 51 may not contain the Mn-activated fluoride complex phosphor but may contain the Mn-activated MGF phosphor. The first layer 51 may contain both a Mn-activated fluoride complex phosphor and a Mn-activated MGF phosphor.

Fluoride Fluoride The luminous flux of the red luminescent phosphor can be increased by including a fluoride phosphor containing at least one of the Mn-activated fluoride complex phosphor and the Mn-activated MGF phosphor in the first layer.

Mn-Activated Fluoride Complex Fluoride The Mn-activated Fluoride Complex Fluoride is selected from at least one selected from the group consisting of alkali metal elements and NH ₄₊ , and from the group consisting of Group 4 elements and Group 14 elements ^. Fluoride complex phosphors containing at least one element in their composition and activated with Mn can be mentioned. The Mn-activated fluoride complex phosphor preferably absorbs light from a light source having an emission peak wavelength in the range of 400 nm or more and 480 nm or less, and preferably has a peak wavelength in the range of 610 nm or more and 650 nm or less. It is more preferable to have a peak wavelength in the range of more than 645 nm. The Mn-activated fluoride complex phosphor has a relatively narrow half-value width. The half-value width in the emission spectrum of the Mn-activated fluoride complex phosphor is specifically 20 nm or less, preferably 10 nm or less, and more preferably 5 nm or less. The Mn-activated fluoride complex phosphor may have a plurality of peaks in the range of 610 nm or more and 650 nm or less in the emission spectrum. By including the Mn-activated fluoride complex phosphor in the first layer, the luminous flux of the light emitting device that emits red light can be improved.

The Mn-activated fluoride complex phosphor preferably has a composition represented by the following formula (I).
A ₂ [M ^a _1-a Mn ^{4 +} _a F ₆ ] (I)
(In formula (I), ^A is at least one selected from the group consisting of alkali metal elements and NH ₄₊ , and ^Ma is at least selected from the group consisting of Group 4 elements and Group 14 elements. It is a kind of element, and a is a number satisfying 0 <a <0.2.)

The Mn-activated fluoride complex phosphor is preferably particles. When the Mn-activated fluoride complex phosphor is a particle, the average particle size of the Mn-activated fluoride complex phosphor particle is preferably in the range of 10 μm or more and 90 μm or less, and preferably in the range of 15 μm or more and 70 μm or less. Is more preferable, and more preferably in the range of 20 μm or more and 60 μm or less. The average particle size of the particles of the phosphor can be measured by the Fisher Sub-Sieve Sizar method (also referred to as “FSSS method”). The FSSS method is a kind of air permeation method, and is a method of measuring the specific surface area by utilizing the flow resistance of air and mainly determining the particle size of primary particles. The average particle size measured by the FSSS method is the Fisher Sub-Sizar's Number. When the Mn-activated fluoride complex phosphor is a particle and the average particle size measured by the FSSS method is within the range of 10 μm or more and 90 μm or less, the light from the light source is efficiently wavelength-converted to emit red light more efficiently. Can be done. If the Mn-activated fluoride complex phosphor is a particle and the average particle size is less than 10 μm, the light from the light source may not be efficiently wavelength-converted. If the Mn-activated fluoride complex phosphor is a particle and the average particle size exceeds 90 μm, it may be difficult to handle when forming the first layer. There may be unevenness.

When the fluoride phosphor is a particle, the average particle size of the fluoride phosphor particle contained in the first layer is that of the nitride phosphor particle when the nitride phosphor contained in the second layer is a particle. It is preferably larger than the average particle size. When the average particle size of the fluoride fluorescent particles contained in the first layer is larger than the average particle size of the nitride fluorescent particles contained in the second layer, the light source is arranged so as to be orthogonal to the direction of gravity. In the light emitting element, the first layer, and the second layer, the fluoride phosphor in the first layer is likely to be arranged on the light emitting element side by natural sedimentation or centrifugal sedimentation, and the nitride phosphor in the second layer also emits light. It becomes easy to arrange on the element and the first layer side.

Mn-activated MGF phosphors Mn-activated MGF phosphors include magnesium oxides, oxides containing at least one element selected from the group consisting of alkali metal elements and rare earth metal elements, magnesium fluorides, and germanium oxides. , An oxide containing at least one element selected from Group 13 elements is included in the composition. The Mn-activated MGF phosphor absorbs light from a light source having an emission peak wavelength in the range of, for example, 400 nm or more and 480 nm or less, and preferably has an emission peak wavelength in the range of 640 nm or more and 680 nm or less, more preferably. It has an emission peak wavelength in the range of 640 nm or more and 670 nm or less, and more preferably has an emission peak wavelength in the range of 645 nm or more and 670 nm or less. The half width of the Mn-activated MGF phosphor is specifically 30 nm or less, preferably 28 nm or less, and more preferably 25 nm or less. The Mn-activated MGF phosphor may have a plurality of peaks in the range of 640 nm or more and 680 nm or less in the emission spectrum. By including the Mn-activated MGF phosphor in the first layer, the luminous flux of the light emitting device that emits red light can be improved.

The Mn-activated MGF fluorescent substance preferably has a composition represented by either the following formula (II-I) or (II-II).
3.5MgO ・ 0.5MgF2 ・_GeO2 : Mn ( _II -I)
(I-j) MgO · (j / 2) M ^b ₂ O ₃ · kmgF ₂ · mCaF ₂ · (1-n) GeO ₂ · (n / 2) Mc ₂ O ₃ : ^{zMn 4+} (II-II) )
(In the formula (II-II), M ^b is Li, Na, K, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb. And Lu, at least one element selected from the group consisting of Al, Ga and In, Mc is at least one element selected from the group consisting of Al, Ga and In, ⁱ , j, k, m, n and z. 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. It is a number to meet.)

Second layer The second layer 52 covers at least a part of the first layer 51 and constitutes the fluorescent member 50 together with the first layer 51. The second layer 52 preferably includes a resin or glass and a nitride phosphor 72 that wavelength-converts the light emitted from the light source 10 and / or the first layer 51. The second layer 52 may contain a phosphor other than the nitride phosphor 72, which converts the light from the light source 10 into wavelength and emits red light. As the nitride phosphor 72, one kind of nitride phosphor may be used, or two or more kinds of nitride phosphors having different phosphor compositions may be used. The second layer 52 is preferably arranged so as to be in contact with at least a part of the first layer 51. When the second layer 52 is arranged so as to be in contact with at least a part of the first layer 51, the first layer 52 is more spaced than the first layer 51 when the second layer 52 is arranged so as to be in contact with at least a part of the first layer 51. The light emitted from the 51 or the light passing through the first layer 51 is easily absorbed, the light emitted from the light source 10 and / or the first layer 51 is easily absorbed, the wavelength can be efficiently converted, and the luminous flux can be converted. Improved red emission is obtained.

Nitride Phylogenate The nitride phosphor is selected from the group consisting of a nitride phosphor activated with europium containing at least one of calcium and strontium, silicon and aluminum in its composition, or an alkaline earth metal element. Examples thereof include a nitride phosphor whose composition contains at least one element to be formed, at least one element selected from the group consisting of alkali metal elements, and aluminum, and is activated with europium. The nitride phosphor is composed of at least one of calcium and strontium, silicon and aluminum, which easily absorb light from a light source, for example, light from a light source having an emission peak wavelength in the range of 400 nm or more and 480 nm or less. It is preferably a nitride phosphor activated with europium. The nitride phosphor easily absorbs the light emitted from the light source efficiently, and converts the light emitted from the light source into wavelength without substantially exiting the light in a specific wavelength range from the light emitting device to obtain color purity. Good red emission is obtained. The light in the wavelength range that does not substantially escape from the light emitting device may be light from a light source having a emission peak wavelength in the range of, for example, 400 nm or more and 480 nm or less. The fact that light in a specific wavelength range does not substantially escape from the light emitting device is the largest in the emission spectrum of a light emitting device containing a fluoride phosphor in the first layer and a nitride phosphor in the second layer. The reference emission intensity is the smallest 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, respectively, with the emission peak wavelength as the center, and when the reference emission intensity is 1, the light source It means that the emission intensity ratio of the maximum emission peak wavelength is in the range of more than 0 and 0.1 or less.

At least one element selected from the group consisting of a nitride phosphor activated with europium containing at least one of calcium and strontium, silicon and aluminum in the composition, or an alkaline earth metal element, and aluminum. The strontium-activated nitride phosphor absorbs light from a light source having an emission peak wavelength in the range of, for example, 400 nm or more and 480 nm or less, and has a peak wavelength in the range of 620 nm or more and 660 nm or less. It is preferable to have.

The nitride fluorophore is preferably particles. When the nitride phosphor is a particle, the average particle size of the nitride phosphor measured by the FSSS method is preferably in the range of 5 μm or more and 50 μm or less, and preferably in the range of 10 μm or more and 40 μm or less. It is more preferably in the range of 15 μm or more and 35 μm or less. When the nitride phosphor is a particle and the average particle size measured by the FSSS method is within the range of 5 μm or more and 50 μm or less, the light from the light source is efficiently absorbed and the light in a specific wavelength range is substantially emitted from the light emitting device. The light emitted from the light source is wavelength-converted without escaping, and red light emission with good color purity can be obtained. If the nitride phosphor is a particle and the average particle size is less than 5 μm, the efficiency of wavelength conversion of light from a light source may decrease. When the nitride phosphor is a particle and the average particle size exceeds 50 μm, the number of phosphors per mass of the phosphor contained in the second layer is reduced, and the scattering of light in the second layer is reduced. For example, it may be difficult to convert the wavelength so that the light from the light source does not substantially escape.

The nitride fluorophore preferably has a composition represented by the following formula (III). When a nitride phosphor having the composition represented by the formula (III) is used, it is easy to absorb the light emitted from the light source and the light having an emission peak wavelength within the range of 400 nm or more and 480 nm or less, and the light source can easily absorb the light. It is possible to suppress the emitted light from escaping from the light source without converting the wavelength, and red light emission with good color purity can be obtained.
(Ca _1-s-t Sr _s Eu _t ) _x Al _u Si _v N _w (III)
(In formula (III), s, t, u, v, w and x are 0 ≦ s ≦ 1, 0 <t <1.0, 0 <s + t <1.0, 0.8 ≦ x ≦ 1, respectively. .0, 0.8 ≤ u ≤ 1.2, 0.8 ≤ v ≤ 1.2, 1.9 ≤ u + v ≤ 2.1, 2.5 ≤ w ≤ 3.5.)

The nitride fluorophore may be an Eu-activated nitride fluorophore having a composition represented by the following formula (IV).
(Ca _b Sr _1-b-c-d Ba _c Eu _d ) _e M ^d _f Al ₃ N _g (IV)
(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 0, respectively. ≦ b <1.0, 0.001 <c ≦ 0.1, 0 ≦ d ≦ 0.2, 3.0 ≦ e ≦ 5.0, 0.8 ≦ f ≦ 1.05, 0.8 ≦ g It is a number satisfying ≦ 1.05.)

The nitride fluorophore may be an Eu-activated nitride fluorophore having a composition represented by the following formula (V).
M ^e _h M ^f _o Eu _p Al ₃ N _q (V)
(In the formula, ^{Me 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. Yes, h, o, p, and q are 0.80 ≦ h ≦ 1.1, 0.4 ≦ o ≦ 1.8, 0.001 <p ≦ 0.1, 1.5 ≦ q ≦ 5, respectively. It is a number that satisfies .0.)

The resin used for the resin 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. Above all, the resin used for the first layer 51 or the second layer 52 is more preferably a silicone resin or a modified silicone resin having excellent heat resistance and weather resistance. Examples of the silicone resin include dimethyl silicone resin, phenyl-methyl silicone resin, and diphenyl silicone resin. As the resin used for the first layer 51 or the second layer 52, one kind of resin may be used alone, or two or more kinds may be used in combination. The resin contained in the first layer 51 or the second layer 52 may be the same resin or different resins. In order to efficiently convert the wavelength of the light emitted from the light source or the first layer by the second layer 52, it is preferable that the first layer 51 and the second layer 52 have a small difference in the refractive index, and the difference in the refractive index is small. In order to do so, it is preferable to use the same type of resin.

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.

The light emitting device uses the smallest 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, as the reference light emission intensity, centering on the maximum light emission peak wavelength in the light emission spectrum of the light emission device. When the reference emission intensity is 1, the emission intensity ratio of the maximum emission peak wavelength of the light source is in the range of more than 0 and 0.1 or less, and the emission intensity ratio of the maximum emission peak wavelength is 2.8. It emits light that exceeds. When the maximum emission peak wavelength in the emission spectrum of the light emitting device is less than 645 nm, the reference emission intensity is within the range of 15 nm from the center to the long wavelength side and the short wavelength side, respectively, with the maximum emission peak wavelength as the center. It is preferably the lowest emission intensity in the spectrum. When the maximum emission peak wavelength in the emission spectrum of the light emitting device is 645 nm or more, the reference emission intensity is within the range of 30 nm from the center to the long wavelength side and the short wavelength side, respectively, with the maximum emission peak wavelength as the center. It is preferable that the emission intensity is the smallest in the emission spectrum of.

In the emission spectrum of the light emitting device, the maximum emission peak wavelength is in the wavelength range of the red region. In the emission spectrum of the light emitting device, the maximum emission peak wavelength is preferably in the range of 610 nm or more and 670 nm or less, and more preferably in the range of 620 nm or more and 670 nm or less. In the emission spectrum of the light emitting device, the maximum emission peak is mainly derived from the red emission emitted from one of the fluoride phosphors of the Mn-activated fluoride complex phosphor or the Mn-activated MGF phosphor. In the emission spectrum of the light emitting device, the smallest 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, centering on the maximum emission peak wavelength is also the wavelength in the red region. It is within the range 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, the spectrum derived from the red emission emitted from one of the fluoride phosphors of the Mn-activated fluoride complex phosphor or the Mn-activated MGF phosphor, and the red emission emitted from the nitride phosphor. It is difficult to distinguish from the derived spectrum, and it is emitted from the nitride phosphor from the maximum emission peak wavelength to the long wavelength side and the short wavelength side, even at the smallest emission intensity in the emission spectrum within the range of 15 nm or 30 nm, respectively. There is a case where the one derived from the red emission emitted and the one derived from the red emission emitted from one of the fluoride phosphors of the Mn-activated fluoride complex phosphor or the Mn-activated MGF phosphor are mixed.

In the light emitting device, when the minimum light emission intensity in the light emission spectrum within the range of 15 nm or 30 nm from the maximum light emission peak wavelength to the long wavelength side and the short wavelength side, respectively, is set as the reference light emission intensity, and the reference light emission intensity is set to 1. In addition, it emits light having an emission intensity ratio of the maximum emission peak wavelength of the light source exceeding 0 and 0.1 or less. In the emission spectrum of the light emitting device, when the emission intensity ratio of the maximum emission peak wavelength of the light source to the reference emission intensity is more than 0 and 0.1 or less, the light emitted from the light emitting device is substantially the light from the light source. When the light from the light source is in the blue region of 400 nm or more and 480 nm or less, the blue light does not substantially escape from the light emitting device, so that red light emission with high color purity can be obtained. ..

In the light emitting device, when the minimum light emission intensity in the light emission spectrum within the range of 15 nm or 30 nm from the maximum light emission peak wavelength to the long wavelength side and the short wavelength side, respectively, is set as the reference light emission intensity, and the standard light emission intensity is set to 1. In addition, it emits light having an emission intensity ratio of the maximum emission peak wavelength exceeding 2.8. 3. The light emitting device emits light having a maximum light emission peak wavelength emission intensity ratio of preferably 3.0 or more and 12.0 or less when the reference emission intensity is 1 in the emission spectrum. It emits light of 5 or more and 11.0 or less. When the emission intensity ratio of the maximum emission peak wavelength exceeds 2.8 when the reference emission intensity is set to 1 in the emission spectrum, the light emitting device emits red having a high luminous flux. As the main wavelength of the red light emitted from the light emitting device shifts to the longer wavelength side, the visual sensitivity tends to decrease away from the vicinity of 555 nm, which has the highest visual sensitivity, and the luminous flux tends to decrease. Even when the main wavelength moves to the long wavelength side, the light emitting device emits a high luminous flux when the emission intensity of the maximum emission peak wavelength when the reference emission intensity in the emission spectrum is 1 exceeds 2.8. It emits a maintained red color. In the emission spectrum, when the emission intensity ratio of the maximum emission peak wavelength is 3.0 or more and 12.0 or less when the reference emission intensity is 1, the light emitting device has a higher luminous flux and color purity. It emits a higher red color. In particular, when the first layer contains the Mn-activated fluoride complex phosphor and does not contain the Mn-activated MGF phosphor, the light emitting device emits light within the range of 15 nm from the maximum emission peak wavelength to the long wavelength side and the short wavelength side, respectively. When the smallest emission intensity in the spectrum is set as the reference emission intensity and the reference emission intensity is 1, and the emission intensity ratio of the maximum emission peak wavelength is 3.0 or more and 11.0 or less, the light beam is further higher and the color is increased. It emits a red color with even higher purity. The main wavelength is the chromaticity coordinates of white light (x = 0.333, y = 0.333) and the chromaticity coordinates of light emitted by the light emitting device (x, y) in the chromaticity diagram of the CIE 1931 color system. It is the wavelength of the point where it is connected by a straight line and its extension line and the spectral locus intersect.

The fluoride phosphor 71 contained in the first layer 51 absorbs light from a light source having an emission peak wavelength in the range of, for example, 400 nm or more and 480 nm or less, and emits red light. The fluoride phosphor 71 absorbs light from a light source having an emission peak wavelength in the range of, for example, 400 nm or more and 480 nm or less, which is lower than that of the nitride phosphor 72 contained in the second layer 52, and emits light from the light source. The light from the light source escapes from the first layer 51 because it cannot be completely absorbed. The light from the light source 10 that could not be absorbed by the fluoride phosphor 71 contained in the first layer 51 and escaped from the first layer 51 is better absorbed from the light source 10 than the fluoride phosphor 71 in the second layer. It is absorbed by the nitride phosphor 72 contained in 52, and the blue light of 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 having a high color purity and a 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. Yes, the difference in refractive index 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 the particles of a plurality of fluoride phosphors are irradiated with light, the proportion of each fluoride phosphor particles reflected is small and the optical path length is short, so that the reflectance is lower than the actual reflectance. It has not been. On the other hand, 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 1.4 to 1.5. It is in the vicinity, and the difference in refractive index 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 light is applied to the particles of a plurality of nitride phosphors, the ratio of reflection by the particles of each nitride phosphor is large, the light is scattered, and the optical path length becomes longer, so that the actual reflectance is higher than the actual reflectance. Is also reflected at a high rate. For example, when a light source having an emission peak near 450 nm is used, the fluoride phosphor 71 contained in the first layer 51 absorbs 50% or more and 90% or less of the light from the light source, but from the light source. More than 10% of the light is reflected or transmitted. On the other hand, the nitride phosphor 72 contained in the second layer 52 absorbs 90% or more of the light from the light source, but reflects or transmits only 8% or less of the light from the light source. The reflection spectrum and the excitation spectrum of the phosphor are values for reference only.
Therefore, when a mixture of both a fluoride phosphor and a nitride phosphor is used as the resin, the light from the light source passes through the mixture in a large proportion, the light from the light source leaks, and the red color has high color purity. It is difficult to obtain a light emitting device for light emission. On the other hand, in the present embodiment, a red light emitting device having high color purity can be obtained by mixing a specific fluorescent substance in the first layer and the second layer and determining the order of arrangement thereof.

The light emitting device covers at least a part of the light source, a first layer containing a Mn-activated MGF phosphor that covers at least a part of the light source and wavelength-converts the light emitted from the light source, and at least a part of the first layer. A second layer containing a light source and / or a nitride phosphor that wavelength-converts the light emitted from the first layer, and from the center with the maximum emission peak wavelength in the emission spectrum of the light emitting device as the center. When the minimum emission intensity in the emission spectrum within the range of 30 nm on the long wavelength side and the short wavelength side is set as the reference emission intensity and the reference emission intensity is 1, the emission intensity ratio of the maximum emission peak wavelength of the light source is It is preferable that the light emitting device emits red light, which is in the range of more than 0 and 0.1 or less, and has an emission intensity ratio of the maximum emission peak wavelength of 2.8 or more.

The amount of the fluoride phosphor or the nitride phosphor with respect to the resin or the glass in the first layer or the second layer is preferably the amount of the fluoride phosphor or the nitride phosphor with respect to 100 parts by mass of the resin or the glass. It is 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. When the fluoride phosphor contained in the first layer is contained in the range of 20 parts by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the resin or glass contained in the first layer, it has a high luminous flux. A red emission is obtained. If the nitride phosphor contained in the second layer is within the range of 20 parts by mass or more and 200 parts by mass or less with respect to 100 parts by mass of the resin or glass contained in the second layer, the light source and / or the first layer Efficiently absorbs the light emitted from the light source to convert the wavelength, and red light emission with high color purity can be obtained.

The mass ratio of the fluoride phosphor contained in the first layer to the nitride phosphor contained in the second layer is, when the nitride phosphor is 100 parts by mass, the fluoride phosphor is preferably 20 mass by mass. It is in the range of 2 parts or more and 200 parts by mass or less, more preferably 40 parts by mass or more and 180 parts by mass or less, and further preferably 60 parts by mass or more and 180 parts by mass or less. When 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 having a high luminous flux can be obtained.

In addition to the phosphor, resin or glass, the first layer or the second layer may contain other components such as fillers, light stabilizers and colorants. Examples of the filler include silica, barium titanate, titanium oxide, aluminum oxide and the like.

The thickness of the first layer is T1, and the thickness of the second layer is T2. When the light source is a light emitting element, it is preferable 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 in the range of 1.1 times or more and 3 times or less with respect to the thickness of the light emitting element, and is 1.3 times or more and 2.6 times or less. The thickness is more preferably within the range of 1.6 times or more, and further preferably 2.3 times or less. If the total thickness T1 + T2 of the first layer and the second layer is within the range of 1.1 times or more and 3 times or less the thickness Te of the light emitting element, the light emitted from the light source in the first layer. It is easy to absorb light, it can efficiently convert the wavelength, it emits red light with improved light beam, it is easy to efficiently absorb the light emitted from the light source even in the second layer, and the light in a specific wavelength range from the light emitting device. However, the light emitted from the light source is wavelength-converted to emit red light having good color purity. In the light emitting device 101 of the first embodiment shown in FIG. 1A, as shown in FIG. 1B, the thickness of the light emitting element 10 is formed by a pair of electrodes facing the surface 10b of the light emitting element 10 mounted on the first lead 20. The thickness between the first surface 10a and the surface 10a is referred to as the thickness Te of the light emitting element 10. Further, also in the light emitting device 102 of the second aspect and the light emitting device 103 of the third aspect described later, the thickness of the light emitting element 10 is the second surface 10b of one of the light emitting elements 10 and the other first surface facing the second surface 10b. The thickness between the surface 10a and the surface 10a. In the light emitting device 101 of the first embodiment shown in FIG. 1B, the total thickness T1 + T2 of the first layer 51 and the second layer 52 is the first of the light emitting elements 10 in all the portions on 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 on the same line perpendicular to the surface 10a may be within the range of 1.1 times or more and 3 times or less the thickness Te of the light emitting element 10. The total thickness of the first layer 51 and the second layer 52 is generally from the first surface 10a facing the surface 10b mounted on the first lead 20 of the light emitting element 10 to the surface of the second layer 52. The distance can be measured 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 in the range of 165 μm or more and 450 μm or less.

The thickness T1 of the first layer 51 may be larger than the thickness T2 of the second layer 52. When the thickness T2 of the second layer 52 is 1, the thickness T1 of the first layer 51 may be in the range of 1.1 times or more and 5 times or less, and 1.2 times or more and 4.5 times or less. It may be within the range of 1.3 times or more and 4 times or less, 3.5 times or less, 3 times or less, or 2 times or less. The ratio of the thickness T1 of the first layer 51 to the thickness T2 of the second layer 52 is as shown in FIG. 1B in the light emitting device 101 of the first embodiment shown in FIG. 1A when the light source is the light emitting element 10. The ratio of the thickness T1 of the first layer 51 and 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. Also in the light emitting device of the second aspect and the light emitting device of the third aspect described later, the ratio of the thickness T1 of the first layer and the thickness T2 of the second layer is set on the substrate 200 when the light source is the light emitting element 10. It refers to the ratio of the thickness T1 of the first layer 51 and 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 opposing light emitting element 10. 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 by the first layer 51 can be easily absorbed, the wavelength can be efficiently converted, and the light emitting device 101 can be used. , 102 or 103 emits red light with a high luminous flux.

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 or more and 250 μm or less, the thickness T1 of the first layer may be in the range of 150 μm or more and 400 μm or less, 200 μm. It may be in the range of 350 μm or more, or 200 μm or more and 300 μm or less. When the thickness of the light emitting element is 150 μm and the thickness T1 of the first layer is within the range of 150 μm or more and 400 μm or less, the thickness T2 of the second layer may be within the range of 50 μm or more and 200 μm or less. , It may be in the range of 50 μm or more and 150 μm or less. 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 180 μm or more and 650 μm or less, or 200 μm or more and 600 μm or less. It may be in the range of 230 μm or more and 550 μm or less.

The thickness T1 of the first layer may be the same as or smaller than the thickness T2 of the second layer. The thickness T1 of the first layer may be in the range of 0.1 times or more and 1 times or less, and is in the range of 0.2 times or more and 0.9 times or less when the thickness T2 of the second layer is 1. It may be within the range of 0.3 times or more and 0.8 times or less, 0.7 times or less, or 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 suppresses the intrusion of oxygen and water into the light emitting device, and the fluorofluorescent phosphor easily reacts with oxygen and water. Deterioration is suppressed, and for example, when the light emitting device is continuously lit for a long time, it is possible to suppress a decrease in the luminous flux maintenance rate of the light emitting device.

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 or more and 300 μm or less, the thickness T1 of the first layer may be in the range of 100 μm or more and 300 μm or less, 150 μm. It may be within the range of 300 μm or more. When the thickness of the light emitting element is 150 μm and the thickness T1 of the first layer is within the range of 100 μm or more and 300 μm or less, the thickness T2 of the second layer may be within the range of 50 μm or more and 300 μm or less. , It may be in the range of 100 μm or more and 250 μm or less. 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 150 μm or more and 600 μm or less, and may be in the range of 200 μm or more and 600 μm or less. It may be in the range of 230 μm or more and 550 μm or less.

In the translucent body light emitting device 101, the second layer 52 is arranged so as to be in contact with at least a part of the first layer 51, and is arranged on the opposite side of the second layer 52 to the side in contact with the first layer 51. It is preferable to include the translucent body 90. When the second layer 52 is arranged so as to be in contact with at least a part of the first layer 51, it transmits the light wavelength-converted by the fluoride phosphor 71 contained in the first layer 51 and the first layer 51. The light emitted from the light source 10 is efficiently wavelength-converted, and red light emission having a high luminous flux can be obtained from the light emitting device 101. In the light emitting device 101, oxygen and water existing outside the light emitting device 101 enter the light emitting device 101 by the translucent body 90 arranged on the opposite side of the second layer 52 to the side in contact with the first layer 51. It is possible to protect the nitride phosphor 72 contained in the second layer 52 and maintain a high luminous flux of red emission. Further, the light emitting device 101 can improve the strength of the light emitting device 101 by including the translucent body 90. The thickness of the translucent body is not particularly limited as long as it can suppress the intrusion of oxygen and water into the light emitting device, and can be, for example, in the range of 30 μm or more and 300 μm or less, preferably in the range of 40 μm or more and 280 μm or less. It is more preferably in the range of 50 μm or more and 270 μm or less.

The translucent body is preferably made of a glass material. Examples of the glass material constituting the translucent body include borosilicate glass, quartz glass, sapphire glass, calcium fluoride glass, aluminoborosilicate glass, oxynitride glass, and chalcogenide glass. If the translucent body is made of a glass material, it is possible to further suppress the intrusion of oxygen and water into the light emitting device, and the light emitting device does not interfere with the red light emitted from the second layer. The strength of the can be improved. When the first layer or the second layer is made of a glass material, the translucent body may be made of the same kind of glass material as the second layer, and may be made of a glass material different from that of the second layer. May be good.

The translucent body and the molded body or the second layer may be joined by an adhesive. As the adhesive, an adhesive containing an epoxy resin, a silicone resin, or the like may be used, or an organic adhesive having a high refractive index, an inorganic adhesive, low melting point glass, or the like may be used.

Reflecting member The light emitting device 101 preferably includes a reflecting member 80 arranged so as to be in contact with a part of the light source 10, a part of the first layer 51, and a part of the second layer 52. It is preferable that the reflective member 80 is in contact with a part of the light source 10, a part of the first layer 51, and a part of the second layer 52, and is arranged from the bottom surface to the inner wall surface of the recess 40r of the molded body 40. .. The reflecting member 80 can efficiently reflect the light emitted from the light source 10 and the light wavelength-converted by the first layer 51 and the second layer 52, and improve the luminous flux of the red emission emitted from the light emitting device 101. can.

The reflective member preferably contains a reflective material and resin or glass. Examples of the reflective material include oxides containing at least one selected from the group consisting of yttrium, zirconium, aluminum, and titanium having a reflectance at a specific wavelength of a specific value or more. For example, an oxide containing at least one selected from the group consisting of yttrium, zirconium, aluminum and titanium, which has a reflectance of 50% or more of light from a light source having an emission peak wavelength in the range of 400 nm or more and 480 nm or less. Be done. The reflective member may contain a white pigment whose reflectance at a specific wavelength is not equal to or higher than a specific value. White pigments include 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, zirconium oxide. One of these can be used alone or in combination of two or more of them. The shape of the white pigment is not particularly limited and may be amorphous or crushed, but a spherical shape is preferable from the viewpoint of fluidity. The particle size of the white pigment is, for example, about 0.1 μm or more and 0.5 μm or less.

In the method of manufacturing the light emitting device 101 of the first aspect, the light source 10 is placed on the first lead 20 constituting the bottom surface of the recess 40r of the molded body 40, and the light extraction surface of at least a part of the light source 10 is taken out. Is covered with the first resin composition containing the first resin and the fluoride phosphor 71, and the first resin composition is cured to form the first layer 51, and at least a part of the first layer 51 is formed. It is preferable to cover the second resin composition containing the second resin and the nitride phosphor 72 and cure the second resin composition to form the second layer 52.

In the step of mounting the light source 10 on the molded body 40, the light source 10 is die-bonded to the first lead 20 and is placed on the first surface 10a for taking out light facing the second surface 10b mounted on the first lead 20. The formed positive and negative electrodes are connected to the first lead 20 and the second lead 30 via the wire 60, respectively. In the molded body 40, the first lead 20 and the second lead 30 are arranged at predetermined positions in the cavity of the resin molding mold, the molding resin is injected into the cavity and cured, and the molded body 40 has the recess 40r. The first lead 20 and the second lead 30 may be integrally molded with a resin in advance, and a molded body 40 may be purchased and used. The reflective member 80 may be formed by injecting a resin composition for a reflective member into the recess 40r of the molded body 40 before forming the first layer 51 and the second layer 52, and the reflective member 80 is provided with the reflective member 80 in advance. You may purchase and use the molded body 40.

In the step of forming the first layer 51, the first resin composition is in contact with at least a part of the light extraction surface of the light source 10 placed in the recess 40r of the molded body 40. Can be dropped using a dispenser or the like to cure the first resin composition to form the first layer 51 containing the fluoride phosphor 71.

In the step of forming the second layer 52, the second resin composition is dropped from above the first layer 51 using a dispenser or the like so as to be in contact with at least a part of the first layer 51, and the second resin composition is formed. The second layer 52 containing the nitride phosphor 72 can be formed so as to be in contact with at least a part of the first layer 51. After forming the second layer 52, the translucent body 90 may be arranged on the side opposite to the side of the second layer 52 that comes into contact with the first layer 51. When a collective molded body in which a plurality of molded bodies including a plurality of recesses 40r are integrally molded is used, an individualization step of cutting the collective molded body into individual molded bodies and individualizing them is included. You may. As a method for individualizing the assembled compact, a method such as cutting with a lead cut mold or a dicing saw, or cutting with a laser beam can be used.

FIG. 2 is a schematic cross-sectional view showing a second aspect of the light emitting device. In the light emitting device 102 showing the second aspect, the light source 10 is the above-mentioned light emitting element with respect to the light emitting device 101 showing the first aspect, and the surface on which the pair of electrodes is formed is flip-chip mounted on the substrate 200. The difference is that, instead of the molded body 40 in which the first lead and the second lead are integrally molded, the resin molded portion 43 which is integrated with the substrate 200 and constitutes the side wall of the recess is provided, and the others are common.

Board The board 200 is mounted with at least one light source 10 and electrically connects the light emitting device 102 to the outside. The substrate 200 includes a flat plate-shaped support member and conductor wiring arranged on the surface and / or inside of the support member. The support member of the substrate 200 may be formed in a flat plate shape, and the support member may be provided with a heat radiating member or a heat radiating terminal. The support member is preferably formed by using an insulating material, and the insulating material constituting the support member includes ceramics such as alumina, aluminum nitride and mullite, phenol resin, epoxy resin, polyimide resin and bismaleimide triazine resin. , Polyphthalamide and other resins. The substrate 200 can be formed by dropping a resin or flowing it into a cavity and curing it. The conductor wiring and the terminal for heat dissipation can be formed by using a metal such as Cu, Ag, Au, Al, Pt, Ti, W, Pd, Fe, Ni, or an alloy thereof. Conductor wiring can be formed by methods such as electrolytic plating, electroless plating, thin film deposition, and sputtering.

As a method of manufacturing the light emitting device 102 of the second aspect, for example, the light source 10 is flip-chip mounted on the substrate 200 in the recess of the resin molding portion 43, and the reflective member 81 is arranged around the light source 10. A method including arranging the first layer 51 so as to be in contact with the reflective member 81 and arranging the second layer 52 on the first layer 51 can be mentioned. The reflective member 81 preferably contains a reflective material and resin or glass as in the reflective member 80, and the reflective material may be made of the same material as the reflective member 80. The reflective member 81 can be formed by dropping a reflective material and a composition for a reflective member containing resin or glass around the light source 10 in the recess of the resin molding portion 43 and curing the composition. can.

When the light source 10 is a light emitting element, even if the surface 10b on which a pair of positive and negative electrodes is formed is mounted on the conductor wiring of the substrate 200 via a bonding member such as a bump, for example, by flip-chip mounting (face-down mounting). good. When the light emitting element is flip-chip mounted (face-down mounted) on the substrate 200 as the light source 10, the first surface 10a facing the surface 10b on which the pair of electrodes of the light source 10 is formed is mainly the light extraction surface. Become.

In the light emitting device 102, the upper surface of the substrate 200 other than the portion 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 reflective members. It is preferably covered with 81. The reflective member 81 can supply the third resin composition constituting the reflective member 81 into the recess 43r of the resin molding portion 43 and cure the third resin composition to form the reflective member 81. The reflective member 81 can use the same raw material as the raw material constituting the reflective member used in the light emitting device 101 of the first aspect, and contains a reflective material or a white pigment, preferably a resin. When the light source 10 mounted on the flip chip is a light emitting element, the reflective member 81 may be arranged so as to cover the entire side surface of the light emitting element, or may be arranged so as to cover a part of the side surface. When the light source 10 mounted on the flip chip is a light emitting element, the reflective member 81 covers a part of the side surface of the light emitting element or the entire surface of the side surface, and the resin molding portion forming the side wall of the recess from the upper surface of the substrate 200. When the inner surface of the recess of the resin molding portion 43 is covered to a height corresponding to the upper surface of the 43, the light is not taken out from the side surface of the second layer 52 which can be the light emitting surface, so that the light emitting direction is changed. Red light can be emitted from the upper surface of the second layer 52 without variation.

As the first layer 51 containing the fluoride phosphor 71, the first resin composition containing the fluoride phosphor 71 and the resin may be used, and the first resin composition may be cured to form the first layer 51. can. It is preferable that the first resin composition is dropped into the recess 43r of the resin molding portion 43 and cured so as to come into contact with the reflective member 81. A second resin composition containing the nitride phosphor 72 and the resin is dropped from above the first layer 51 to cure the second resin composition so that the second resin composition comes into contact with the first layer 51. The layer 52 can be formed. Instead of dropping the second resin composition onto the first layer 51, the second resin composition was cured separately from the first layer 51 to form the second layer 52, and the second layer 51 was formed. The first layer 51 and the second layer 52 may be joined by contacting each other and using an adhesive. Before the resin or glass is cured, the first layer 51 is arranged so that the fluoride phosphor 71 is biased toward the light source 10 by, for example, centrifugal sedimentation, and then the first resin composition is cured. The first layer 51 may be formed. Further, in the second layer 52 as well, before the resin or the glass is cured, the nitride phosphor 72 is arranged so as to be biased toward the first layer 51 by natural sedimentation or centrifugal sedimentation, and then the second layer 52 is second. The resin composition may be cured to form the second layer 52. When the fluoride fluorescent substance 71 or the nitride fluorescent substance 72 is unevenly present, the fluoride fluorescent substance 71 or the nitride fluorescent substance 72 does not exist between the first layer 51 and the second layer 52. A layer may be formed, or a clear layer in which the nitride phosphor 72 does not exist may be formed on the opposite side of the second layer 52 in contact with the first layer 51. When a clear layer in which the nitride phosphor 72 does not exist is formed on the opposite side of the second layer 52 in contact with the first layer 51, the clear layer allows oxygen and water to enter the light emitting device 102. It can be suppressed.

In the case of an aggregate in which the resin molding portion 43 having a plurality of recesses 43r is integrally molded, the aggregate is cut into individual light emitting devices 102 including at least one light source 10 to be individualized. It may include a disinfection step. As a method for individualizing the aggregate, the same method as the above-mentioned method for individualizing the assembled compact can be used.

In the light emitting device 102 of the second aspect, the total thickness T1 + T2 of the first layer and the second layer on the first surface 10a of the light emitting element 10 and on the same line in the direction perpendicular to the first surface 10a of the light emitting element 10. Is preferably larger than the thickness Te of the light emitting element. In the light emitting device 102 of the second aspect, the total thickness T1 + T2 of the first layer and the second layer on the first surface 10a of the light emitting element 10 and on the same line in the 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, and more preferably 1.3 times or more and 2.6 times or less with respect to the thickness Te of the light emitting element. , It is more preferable that the thickness is within the range of 1.6 times or more and 2.3 times or less. In the light emitting device 102 of the second aspect, 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 the direction perpendicular to the first surface 10a of the light emitting element 10 is the second layer. It may be larger than the thickness T2 of 52. When the thickness T2 of the second layer 52 is 1, the thickness T1 of the first layer 51 may be in the range of 1.1 times or more and 5 times or less, and 1.2 times or more and 4.5 times or less. It may be within the range of 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 aspect, 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 the direction perpendicular to the first surface 10a of the light emitting element 10 is the second layer. It may be the same as or smaller than the thickness T2 of 52. The thickness T1 of the first layer 51 may be in the range of 0.1 times or more and 1 times or less, and 0.2 times or more and 0.9 times or less when the thickness T2 of the second layer 52 is 1. It may be within the range of 0.3 times or more and 0.8 times or less, 0.7 times or less, and 0.6 times or less.

FIG. 3 is a schematic cross-sectional view showing a third aspect of the light emitting device. The light emitting device 103 showing the third aspect has a point where the boundary between the first layer 51 and the second layer 52 does not exist, the intermediate region 53 exists, and the reflection with respect to the light emitting device 102 showing the second aspect. The difference is that the member 81 covers a part of the side surface of the light source 10, and the others are common.

In the intermediate region light emitting device 103, the first layer 51 and the second layer 52 are continuously arranged, and the fluoride phosphor 71 and the nitride phosphor 72 are arranged between the first layer 51 and the second layer 52. It comprises an intermediate region 53 containing resin or glass. The intermediate region 53 contains the fluoride phosphor 71 and resin or glass, and after arranging the first resin composition constituting the first layer 51 around the light source 10, before the first resin composition is cured. The second resin composition containing the nitride phosphor 72 and the resin or glass and constituting the second layer 52 is provided so that at least a part of the second resin composition is continuous with the first resin composition. By arranging and then curing the first resin composition and the second resin composition, the first layer 51 containing the fluoride phosphor 71 and the resin or glass, and the fluoride phosphor 71 and the nitride phosphor 72 The intermediate region 53 containing the resin or glass and the second layer 52 containing the nitride phosphor 72 and the resin or glass are continuously produced without boundaries of the respective layers or regions. Compared with the case where there is a boundary between the first layer 51 and the second layer 52, it is better that the first layer 51, the intermediate region 53, and the second layer 52 are arranged continuously without a boundary, the heat from the light source is generated. However, it is easy to dissipate heat to the outside and the heat dissipation is improved.

In the method for producing the light emitting device 103, a first resin composition containing a fluoride phosphor 71 and a resin is potted on a light source 10, and a first resin composition containing a nitride phosphor 72 is contained before the first resin composition is cured. (Ii) Potting the resin composition. Even if the fluoride phosphor 71 in the first resin composition potted on the light source 10 is arranged so as to be biased toward the light source side by natural sedimentation or centrifugal sedimentation before the second resin composition is potted. good. After the second resin composition is potted on the first resin composition, the nitride phosphor 72 may be arranged so as to be unevenly present on the first resin composition side by natural sedimentation or centrifugal sedimentation. Before the first resin composition is cured, the boundary between the first resin composition and the second resin composition does not exist, and the intermediate region 53 in which the fluoride phosphor 71 and the nitride phosphor 72 coexist is formed. It is formed. At this time, regarding the particle size of the phosphors of the first layer 51 and the second layer 52, the nitride phosphor 72 in which the average particle size of the fluoride phosphor 71 contained in the first layer 51 is contained in the second layer 52. It is preferable that the particle size is larger than the average particle size of. By doing so, 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 is the first layer other than the intermediate region 53. It is possible to suppress the mixture of the nitride phosphors 72 contained in the second layer 52 in the first layer 51 other than the intermediate region 53, and it is possible to suppress the mixture in the first layer 51 other than the intermediate region 53. The decrease can be suppressed. When there is no boundary between the first layer 51 and the second layer 52, and an intermediate region 53 containing a fluoride phosphor 71 and a nitride phosphor 72 having better thermal conductivity than resin or glass is formed. Is a resin having a lower thermal conductivity in the heat dissipation path than when a clear layer in which the fluoride phosphor 71 and the nitride phosphor 72 are not present is formed between the first layer 51 and the second layer 52. Since the path through which heat passes through the glass is shortened, the heat dissipated from the light source 10 is improved. The second layer 52 may be formed with a clear layer containing no nitride phosphor 72 on the opposite side of the light source 10. When a clear layer in which the nitride phosphor 72 does not exist is formed on the opposite side of the second layer 52 on the light source 10 side, the clear layer can suppress the intrusion of oxygen and water into the light emitting device 103. can.

In the light emitting device 103 of the third aspect, it is difficult to individually measure the thickness of only the intermediate region 53, the thickness T1 of the first layer 51 and the thickness of the intermediate region 53, the thickness T2 of the second layer 52 and the intermediate region 53. It is also difficult to measure the thickness of each separately. When the first layer 51, the second layer 52, and the intermediate region 53 are formed in the light emitting device 103, the total thickness of the first layer 51, the second layer 52, and the intermediate region 53 is the first layer 51. It can be measured as the total thickness T1 + T2 of the thickness T1 of the above and the thickness T2 of the second layer 52. In the light emitting device 103 of the third aspect, the first layer 51, the intermediate region 53, and the second layer on the first surface 10a of the light emitting element 10 and on the same line in the direction perpendicular to the first surface 10a of the light emitting element 10. The total thickness T1 + T2 of 52 is preferably larger than the thickness Te of the light emitting element 10. In the light emitting device 103 of the third aspect, the first layer 51, the intermediate region 53, and the second layer on the first surface 10a of the light emitting element 10 and on the same line in the direction perpendicular to the first surface 10a of the light emitting element 10. The total thickness T1 + T2 of 52 is preferably in the range of 1.1 times or more and 3 times or less with respect to the thickness Te of the light emitting element 10, and is in the range of 1.3 times or more and 2.6 times or less. It is more preferable that the thickness is in the range of 1.6 times or more and 2.3 times or less. In the light emitting device 103 of the third aspect, 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 are the same in the direction perpendicular to the first surface 10a of the light emitting element 10. It is preferable that the thickness Te of the light emitting element 10 and the total thickness T1 + T2 of the first layer 51 and the intermediate region 53 and the second layer 52 on the line.

Hereinafter, the present invention will be specifically described with reference to Examples. The present invention is not limited to these examples.

Fluoride complex fluorophore 71-1
As the Mn-activated fluoride complex phosphor 71-1, a fluoride phosphor having a composition represented by K ₂ [SiMn ^{4 +} F ₆ ] was prepared. The emission spectrum and reflection spectrum of the fluoride complex phosphor 71-1 were measured by the method described later. The fluoride complex phosphor 71-1 having the composition represented by K ₂ [SiMn ^{4 +} F ₆ ] had an emission peak wavelength at 631 nm, and the half width of the maximum emission peak was 2.6 nm. When the emission peak wavelength of the excitation light was 450 nm, the reflectance of the fluoride complex phosphor 71-1 was 22.0%. The reflectance measured from the reflection spectrum of each phosphor is a reference value. The refractive index of the fluoride complex phosphors 71-1 and 71-2 was 1.36. The refractive indexes of the fluoride complex phosphor, the MGF phosphor, the nitride phosphor and the silicone resin are calculated values. The average particle size of the fluoride complex phosphor 71-1 measured by the FSSS method described later was 29.0 μm.

Fluoride complex fluorophore 71-2
As the Mn-activated fluoride complex phosphor 71-2, a fluoride phosphor having a composition represented by K ₂ [SiMn ^{4 +} F ₆ ] was prepared. The emission spectrum and reflection spectrum of the fluoride complex phosphor 71-2 were measured by the method described later. The fluoride complex phosphor 71-2 having a composition represented by K ₂ [SiMn ^{4 +} F ₆ ] had an emission peak wavelength at 631 nm, and the half width of the maximum emission peak was 2.6 nm. When the emission peak wavelength of the excitation light was 450 nm, the reflectance of the fluoride complex phosphor 71-2 was 12.2%. The average particle size of the fluoride complex phosphor 71-2 measured by the FSSS method was 70.5 μm.

MG F phosphor 71-3
As the Mn-activated MGF phosphor 71-3, (i-j) MgO · (j / 2) M ^b ₂ O ₃ · ^kmgF ₂ · mCaF ₂ · (1-n) GeO ₂ · (n / 2) Mc ₂ O ₃ : MGF phosphor 71-3 having a composition represented by zMn ⁴⁺ (the above formula (II-II)) was prepared. The emission spectrum and reflection spectrum of the MGF phosphor 71-3 were measured by the method described later. The MGF phosphor 71-3 having the composition represented by the formula (II-II) had an emission peak wavelength at 670 nm, and the half width of the maximum emission peak was 25 nm. When the emission peak wavelength of the excitation light was 450 nm, the reflectance of the MGF phosphor 71-3 was about 40%, and the refractive index was 1.70 to 1.81. The average particle size of the Mn-activated MGF phosphor 71-3 measured by the FSSS method was 20.5 μm.

Nitride fluorophore 72-1
As the nitride fluorophore 72-1, a nitride fluorophore having a composition represented by (Ca, Sr, Eu) AlSiN ₃ was prepared. The emission spectrum and reflection spectrum of the nitride phosphor were measured by the method described later. The nitride phosphor having the composition represented by (Ca, Sr, Eu) AlSiN ₃ had an emission peak wavelength at 635 nm, and the half width of the maximum emission peak was 78.9 nm. When the emission peak wavelength of the excitation light was 450 nm, the reflectance of the nitride phosphor 72-1 was 5.8%. The refractive indexes of the nitride phosphors 72-1, 72-2, 72-3 and 72-4 ranged from 2.15 to 2.25. The average particle size of the nitride phosphor 72-1 measured by the FSSS method was 14.1 μm.

Nitride fluorophore 72-2
As the nitride fluorophore 72-2, a nitride fluorophore having a composition represented by (Ca, Sr, Eu) AlSiN ₃ was prepared. The emission spectrum and reflection spectrum of the nitride phosphor were measured by the method described later. The nitride fluorophore 72-2 having the composition represented by (Ca, Sr, Eu) AlSiN ₃ had an emission peak wavelength at 648 nm, and the half width of the maximum emission peak was 86.8 nm. When the emission peak wavelength of the excitation light was 450 nm, the reflectance of the nitride phosphor 72-2 was 7.0%. The average particle size of the nitride phosphor 72-2 measured by the FSSS method was 10.4 μm.

Nitride fluorophore 72-3
As the nitride fluorophore 72-3, a nitride fluorophore having a composition represented by (Ca, Eu) AlSiN ₃ was prepared. The emission spectrum and reflection spectrum of the nitride phosphor were measured by the method described later. The nitride phosphor 72-3 having the composition represented by (Ca, Eu) AlSiN ₃ had an emission peak wavelength at 665 nm, and the half width of the maximum emission peak was 90.7 nm. When the emission peak wavelength of the excitation light was 450 nm, the reflectance of the nitride phosphor 72-3 was 6.6%. The average particle size of the nitride phosphor 72-3 measured by the FSSS method was 10.2 μm.

Nitride fluorophore 72-4
As the nitride fluorophore 72-4, a nitride fluorophore having a composition represented by (Ca, Sr, Eu) AlSiN ₃ was prepared. The emission spectrum and reflection spectrum of the nitride phosphor were measured by the method described later. The nitride phosphor having the composition represented by (Ca, Sr, Eu) AlSiN ₃ had an emission peak wavelength at 633 nm, and the half width of the maximum emission peak was 76 nm. When the emission peak wavelength of the excitation light was 450 nm, the reflectance of the nitride phosphor 72-4 was 5.0%. The average particle size of the nitride phosphor 72-4 measured by the FSSS method was 12.0 μm.

Evaluation emission spectrum of each fluorescent substance For the fluoride complex fluorescent substance, MGF fluorescent substance, and nitride fluorescent substance, an excitation wavelength of 450 nm was used using a quantum efficiency measuring device (manufactured by Otsuka Electronics Co., Ltd., product name: QE-2000). Light was applied to a fluoride fluorophore or a nitride fluorophore, and the emission spectrum at room temperature (25 ° C. ± 5 ° C.) was measured. FIG. 4 shows the emission spectrum of the fluoride complex phosphor 71-1 having a composition represented by K ₂ [SiMn ^{4 +} F ₆ ]. FIG. 5 shows the emission spectrum of the MGF phosphor 71-3 having the composition represented by the formula (II-II). FIG. 6 shows the emission spectrum of the nitride phosphor 72-1 having a composition represented by (Ca, Sr, Eu) AlSiN ₃ . FIG. 7 shows the emission spectrum of the nitride phosphor 72-3 having a composition represented by (Ca, Eu) AlSiN ₃ .

Reflection spectrum For fluoride complex phosphors, MGF phosphors, and nitride phosphors, use a spectrofluorescence photometer (manufactured by Hitachi High-Technologies Co., Ltd., product name: F-4500) at room temperature (25 ° C ± 5 ° C). Then, the light from the halogen lamp as the excitation light source is irradiated to the fluoride phosphor or the nitride phosphor as the sample, and the wavelengths of the spectrofluorescence photometers on the excitation side and the fluorescence side are matched and scanned to 380 nm or more. The reflection spectrum within the wavelength range of 730 nm or less was measured. Calcium hydrogen phosphate (CaHPO ₄ ) was used as a reference sample. The reflectance of the fluoride complex phosphor, the MGF phosphor, or the nitride phosphor was determined as the relative reflectance based on the reflectance of calcium hydrogen phosphate with respect to the excitation light having an emission peak wavelength of 450 nm.

Average particle size For each phosphor, the average particle size was measured by the FSSS method using Fisher Sub-Sieve Sizer Model 95 (manufactured by Fisher Scientific).

Example 1
The light emitting device 102 according to the embodiment shown in FIG. 2 was manufactured. As the light source 10, a light emitting device made of a GaN-based semiconductor having a emission peak wavelength of 450 nm was used. In the light emitting device 102, a light emitting element which is a light source 10 is flip-chip mounted on a substrate 200. A light source using the first resin composition containing a silicone resin and a fluoride phosphor 71 containing a fluoride complex phosphor 71-1 but not an MGF phosphor in a blending ratio (part by mass) shown in Table 1. The first resin composition was dropped so as to be in contact with at least a part of 10, and the first resin composition was cured to form the first layer 51 containing the fluoride phosphor 71. Next, using the second resin composition containing the silicone resin and the nitride phosphor 72-1 in the blending ratio (parts by mass) shown in Table 1, the first layer 51 is brought into contact with at least a part thereof. The second resin composition was dropped onto the first layer 51, and the second resin composition was cured to form the second layer 52 containing the nitride phosphor 72. The refractive index of the silicone resin was 1.4 to 1.5.

Comparative Example 1
The light emitting device 104 according to the embodiment shown in FIG. 14 was manufactured. The light emitting device 104 is different from the light emitting device 102 of the embodiment shown in FIG. 2 in that the light emitting device 104 includes a fluorescent layer 54 composed of one layer including the nitride phosphor 72-1. The fluorescent layer 54 uses a resin composition for a fluorescent layer containing a silicone resin and a nitride phosphor 72-1 in the blending ratio (parts by mass) shown in Table 1, and is used as a fluorescent layer on at least a part of the light source 10. The resin composition for use was dropped so as to come into contact with the resin composition, and the resin composition was cured to form the fluorescent layer 54.

Comparative Example 2
The light emitting device 105 according to the embodiment shown in FIG. 15 was manufactured. The light emitting device 105 differs from the light emitting device 102 of the embodiment shown in FIG. 2 in that the light emitting device 105 includes a fluorescent layer 55 composed of a fluoride complex phosphor 71-1 and one layer containing the nitride phosphor 72-1. The fluorescent layer 55 uses a resin composition for a fluorescent layer containing a silicone resin, a fluoride complex phosphor 71-1, and a nitride phosphor 72-1 in the blending ratio (parts by mass) shown in Table 1. The resin composition for the fluorescent layer is dropped so as to be in contact with at least a part of the light source 10, and the resin composition is cured to contain the fluoride complex fluorescent substance 71-1 and the nitride fluorescent substance 72-1. Two fluorescent layers 55 were formed.

Comparative Example 3
The light emitting device 106 according to the embodiment shown in FIG. 16 was manufactured. The light emitting device 106 is different from the light emitting device 102 of the embodiment shown in FIG. 2 in that the light emitting device 106 includes a fluorescent layer 56 composed of one layer containing the fluoride complex phosphor 71-1. The fluorescent layer 56 fluoresces at least a part of the light source 10 by using a resin composition for a fluorescent layer containing a silicone resin and a fluoride complex phosphor 71-1 in a blending ratio (part by mass) shown in Table 1. The resin composition for the layer was dropped so as to be in contact with each other, and the resin composition was cured to form one fluorescent layer 56 containing the fluoride complex fluorescent substance 71-1.

Evaluation of light emitting device For the light emitting devices of each example and comparative example, the light emitting spectrum showing the light emitting intensity with respect to the wavelength of each light emitting device was measured by using the same total luminous flux measuring device as the measurement of the relative luminous flux. In the emission spectrum of each light emitting device, the maximum emission peak wavelength and the smallest emission intensity in the emission spectrum in the range of 15 nm or 30 nm from the center to the long wavelength side and the short wavelength side, respectively, with the maximum emission peak wavelength as the center. , The wavelength was calculated. In the emission spectrum of the light emitting device, the smallest emission intensity in the emission spectrum in the range of 15 nm or 30 nm from the center to the long wavelength side and the short wavelength side, respectively, with the maximum emission peak wavelength and the maximum emission peak wavelength as the reference. The emission intensity was determined, and the emission intensity ratio of the maximum emission peak wavelength when the reference emission intensity was set to 1 and the emission intensity ratio of the emission peak wavelength of the light source were determined. Further, the main wavelengths of the light emitting devices of Examples 1 to 2 and Comparative Examples 1 to 5 were determined. The main wavelength is the chromaticity coordinates of white light (x = 0.333, y = 0.333) and the chromaticity coordinates of light emitted by the light emitting device (x, y) in the chromaticity diagram of the CIE 1931 color system. The wavelength of the point where the extension line and the spectral locus intersect with each other is defined as the main wavelength.

Saturation (x, y)
For the light emitting devices of each Example and Comparative Example, the chromaticity coordinates x and y in the chromaticity diagram of the CIE 1931 system were measured by an optical measurement system combining a multi-channel spectroscope and an integrating sphere.

Color purity (%)
For the light emitting devices of each Example and Comparative Example, the color purity was measured using an optical measurement system combining a multi-channel spectroscope and an integrating sphere. The color purity (%) represents the intensity of the light emitted by the light emitting device.

Luminous flux (lm)
For the light emitting devices of each Example and Comparative Example, the luminous flux was measured using a total luminous flux measuring device using an integrating sphere.

Table 1 shows the evaluation results of the light emitting device according to Example 1, Comparative Examples 1 and 2.

The light emitting device 102 according to the first embodiment has an emission intensity ratio of the maximum emission peak wavelength of 8.1 when the reference emission intensity is 1 in the emission spectrum, and the fluoride fluorescence contained in the first layer 51. The light from the light source 10 that has not been wavelength-converted by the body 71 is efficiently wavelength-converted by the nitride phosphor 72 contained in the second layer 52, so that the blue light emitted from the light source 10 is substantially emitted from the light emitting device 102. Red light emission with high color purity and high luminous flux was obtained without slipping out. The light emitting device 102 according to the first embodiment has a higher luminous flux than the light emitting device 105 according to the comparative example 2 provided with the fluorescent layer 55 including the fluoride complex phosphor 71-1 and the nitride phosphor 72-1. .. This is because the light emitting device 102 according to the first embodiment has a small difference in refractive flux from the resin constituting the first layer 51 in the first layer 51 closer to the light source 10, and the light reflectance is included in the second layer 52. Since the fluoride complex phosphor 71-1 smaller than the nitride phosphor is contained, the blue light from the light source can be efficiently wavelength-converted to increase the luminous flux, and further contained in the second layer 52. It is considered that the nitride phosphor 72-1 was used to convert the wavelength of the blue light from the light source escaped from the first layer 51, so that red light emission having high color purity and high luminous flux could be obtained.

8 and 9 show the emission spectra of the light emitting device according to Example 1 in the wavelength range of 600 nm or more and 660 nm or less. FIG. 10 shows the emission spectrum of the light emitting device according to the first embodiment in the wavelength range of 400 nm or more and 500 nm or less. In the emission spectrum of the light emitting device according to the first embodiment, since the emission peak of the light source is smaller than the maximum emission peak, FIGS. 8 and 9 show the emission spectrum having the maximum emission peak of the light emitting device according to the first embodiment. showed that. In the emission spectrum of the light emitting device of Example 1 shown in FIGS. 8 and 9, the maximum emission peak wavelength is 631 nm, and the maximum emission peak wavelength is within the range of 15 nm from 631 nm to the long wavelength side and the short wavelength side, respectively, that is, 616 nm or more and 646 nm or less. The wavelength showing the smallest emission intensity within the range of 642.1 nm was 642.1 nm. The smallest emission intensity in the range of 616 nm or more and 646 nm or less 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 maximum emission peak wavelength of the light emitting device are The emission intensity ratio was determined. As described above, the emission intensity ratio of the maximum emission peak wavelength was 8.1 when the reference emission intensity in the emission spectrum of the light emitting device was 1. FIG. 10 shows an emission spectrum having the maximum emission peak of the light source of the light emitting device according to the first embodiment. In the emission spectrum of the light emitting device, the emission peak wavelength of the light source was 441.7 nm. When the reference emission intensity in the emission spectrum of the light emitting device was 1, the emission intensity ratio of the maximum emission peak wavelength of the light source was 0.017.

The light emitting device 105 according to Comparative Example 2 includes the nitride phosphor 72-1 and the fluoride complex by including the fluorescent layer 55 containing the nitride phosphor 72-1 and the fluoride complex phosphor 71-1. The light beam was higher than that of the light emitting device 104 of Comparative Example 1 provided with the fluorescent layer 54 containing no phosphor 71-1. On the other hand, since the light emitting device 106 according to Comparative Example 3 includes a fluorescent layer 56 containing the fluoride complex phosphor 71-1 and not the nitride phosphor 72-1, the fluoride complex phosphor 71-1 is provided. The blue light emitted from the light source could not be completely absorbed, the main wavelength could not be measured, and the light emitting device did not emit red light.

Example 2
The light emitting device 102 according to Example 2 was formed in the same manner as in Example 1 except that the nitride phosphor 72-2 was used as the nitride phosphor 72 contained in the second layer 52.

Comparative Example 4
A nitride fluorescent material 72-2 was used as the nitride fluorescent material, and a resin composition for a fluorescent layer containing the nitride fluorescent material 72-2 in the blending ratio (part by mass) shown in Table 2 was used. Except for the above, the light emitting device 104 according to Comparative Example 4 was formed in the same manner as in Comparative Example 1.

Comparative Example 5
A nitride fluorescent material 72-2 was used as the nitride fluorescent material, and a resin composition for a fluorescent layer containing the nitride fluorescent material 72-2 in the blending ratio (part by mass) shown in Table 2 was used. Except for the above, the light emitting device 105 according to Comparative Example 5 was formed in the same manner as in Comparative Example 2.

Table 2 shows the evaluation results of the light emitting device according to Example 2, Comparative Examples 4 and 5 measured by the above-mentioned evaluation method.

The light emitting device 102 according to the second embodiment has a light emission intensity ratio of the maximum light emission peak wavelength of 7.6 when the reference light emission intensity is 1 in the light emission spectrum, and emits light of the maximum light emission peak wavelength of the light source 10. Since the intensity ratio was 0.014, the blue light of the light source 10 did not escape from the light emitting device 102, the color purity was almost the same as that of Comparative Examples 4 and 5, and the luminous flux was high. In the light emitting device 102 according to the second embodiment, the light from the light source 10 whose wavelength is not converted by the fluoride complex phosphor 71-1 contained in the first layer 51 is the nitride phosphor 72 contained in the second layer 52. In order to efficiently convert the wavelength by -2, the blue light of the light source did not escape from the light emitting device 102, and red light having a high luminous flux was obtained.

Reference Examples 3 to 5, Examples 6 and 7
Table 3 shows a fluoride complex phosphor 71-2 as the fluoride phosphor contained in the first layer 51 and a nitride phosphor 72-1 as the nitride phosphor contained in the second layer 52. The light emitting device 102 according to Reference Examples 3 to 5 and Examples 6 and 7 was formed in the same manner as in Example 1 except that the mixture was used so as to have a blending ratio.

Table 3 shows the evaluation results of the light emitting devices according to Reference Examples 3 to 5 and Examples 6 and 7 measured by the above-mentioned evaluation method.

In the light emitting device 102 according to Reference Examples 3 to 5 and Examples 6 and 7, the higher the compounding ratio of the fluoride complex phosphor 71-2 contained in the first layer 51, the more the reference light emission in the light emission spectrum of the light emitting device 102. When the intensity was 1, the emission intensity ratio of the maximum emission peak wavelength became large, and the emission intensity ratio of the emission peak wavelength of the light source became small. From this result, the higher the blending ratio of the fluoride complex phosphor 71-1 contained in the first layer 51, the higher the color purity and the higher the luminous flux, because the blue light emitted from the light source 10 does not escape from the light emitting device 102. A red emission was obtained.

Reference Examples 8 to 10, Examples 11 and 12
Table 4 shows a fluoride complex phosphor 71-2 as the fluoride phosphor 71 contained in the first layer 51, and a nitride phosphor 72-2 as the nitride phosphor 72 contained in the second layer 52. The light emitting devices 102 according to Reference Examples 8 to 10 and Examples 11 and 12 were formed in the same manner as in Example 1 except that they were used so as to have the compounding ratio shown in 1.

Table 4 shows the evaluation results of the light emitting devices according to Reference Examples 8 to 10 and Examples 11 and 12 measured by the above-mentioned evaluation method.

In the light emitting devices 102 according to Reference Examples 8 to 10 and Examples 11 and 12, the higher the compounding ratio of the fluoride complex phosphor 71-2 contained in the first layer 51, the more the reference light emission in the light emission spectrum of the light emitting device 102. When the intensity was 1, the emission intensity ratio of the maximum emission peak wavelength became large, and the emission intensity ratio of the emission peak wavelength of the light source became small. From this result, as the compounding ratio of the fluoride complex phosphor 71 contained in the first layer 51 becomes higher, the blue light emitted from the light source 10 does not escape from the light emitting device 102, and the color purity is high and the luminous flux is high. was gotten.

Example 13
The MGF phosphor 71-3 is used instead of the fluoride complex fluorescent substance 71-1, and the MGF fluorescent substance 71-3 and the nitride fluorescent substance 72-3 are contained in the compounding ratio (part by mass) shown in Table 5. (1) The light emitting device 102 according to the thirteenth embodiment was formed in the same manner as in the first embodiment except that the resin composition was used.

Comparative Example 6
Comparison except that a resin composition for a fluorescent layer containing a nitride phosphor 72-3 having a composition represented by (Ca, Eu) AlSiN ₃ in a blending ratio (part by mass) shown in Table 5 was used. The light emitting device 104 according to Comparative Example 6 was formed in the same manner as in Example 1.

Table 5 shows the evaluation results of the light emitting device according to Example 13 and Comparative Example 6.

In the light emitting device 102 according to the thirteenth embodiment, when the reference light emitting intensity is 1, the light emitting intensity ratio of the maximum light emitting peak wavelength is 3.6 in the light emitting spectrum, and the blue light emitted from the light source 10 is the light emitting device. It was possible to obtain red light emission having high color purity and maintaining a high luminous flux which was almost the same as that of Comparative Example 6 without substantially exiting from 102. As the main wavelength of the red light emitted from the light emitting device shifts to the longer wavelength side, the visual sensitivity tends to decrease away from the vicinity of 555 nm, which is a wavelength at which the human eye can easily focus, and the luminous flux tends to decrease. The light emitting device according to the thirteenth embodiment has a main wavelength of 636.2 nm, and the main wavelength moves to a longer wavelength side by about 5 nm than the light emitting device 104 according to the comparative example 6. The light emitting device according to Example 13 maintained a slightly higher luminous flux than the light emitting device according to Comparative Example 6 even when the main wavelength moved to the long wavelength side, and red light emission maintaining a high light flux was obtained. ..

The light emitting device 104 according to Comparative Example 6 has a low emission intensity ratio of 1.7 at the maximum emission peak wavelength when the reference emission intensity is 1 in the emission spectrum, and the luminous flux is slightly smaller than that of Example 13. It became low.

FIG. 11 shows the emission spectrum of the light emitting device according to the thirteenth embodiment in the wavelength range of 600 nm or more and 800 nm or less. FIG. 12 shows the emission spectrum of the light emitting device according to the thirteenth embodiment in the wavelength range of 400 nm or more and 500 nm or less. In the emission spectrum of the light emitting device according to the thirteenth embodiment, since the emission peak of the light source is smaller than the maximum emission peak, FIG. 11 shows an emission spectrum having the maximum emission peak of the light emitting device according to the thirteenth embodiment. rice field. In the emission spectrum of the light emitting device of Example 13 shown in FIG. 12, the maximum emission peak wavelength is 659.9 nm, which is within the range of 30 nm from 659.9 nm to the long wavelength side and the short wavelength side, that is, 629. The wavelength showing the smallest emission intensity in the range of 9 nm or more and 680.9 nm or less was 630.2 nm. With this reference emission intensity as 1, 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 were obtained. When the reference emission intensity in the emission spectrum of the light emitting device was 1, the emission intensity ratio of the maximum emission peak wavelength was 3.6 as described above. FIG. 12 shows an emission spectrum having the maximum emission peak of the light source of the light emitting device according to the thirteenth embodiment. In the emission spectrum of the light emitting device, the emission peak wavelength of the light source was 443.4 nm. When the reference emission intensity in the emission spectrum of the light emitting device was 1, the emission intensity ratio of the maximum emission peak wavelength of the light source was 0.007.

Example 14
The light emitting device 102 according to the embodiment shown in FIG. 2 was manufactured. As the light source 10, a light emitting device made of a GaN-based semiconductor having a emission peak wavelength of 450 nm was used. In the light emitting device 102, a light emitting element which is a light source 10 is flip-chip mounted on a substrate 200. A first resin composition containing a fluoride phosphor 71 containing a silicone resin and a fluoride complex phosphor 71-1 and not containing an MGF phosphor was prepared. The first resin composition contains 150 parts by mass of the fluoride complex phosphor 71-1 with respect to 100 parts by mass of the silicone resin. The first resin composition was dropped so as to be in contact with at least a part of the light source 10, and the first resin composition was cured to form the first layer 51 containing the fluoride phosphor 71. Next, a second resin composition containing a silicone resin and a nitride phosphor 72-4 was prepared. The second resin composition contains 100 parts by mass of the nitride phosphor 72-4 with respect to 100 parts by mass of the silicone resin. The second resin composition is dropped onto the first layer 51 so as to be in contact with at least a part of the first layer 51, and the second resin composition is cured to be a second layer containing the nitride phosphor 72. 52 was formed. The refractive index of the silicone resin was 1.4 to 1.5. In the obtained light emitting device 102, the fluoride phosphor 71 is biased toward the light emitting element 10 in the first layer 51 due to centrifugal sedimentation, and the fluoride fluorescence is present between the first layer 51 and the second layer 52. A clear layer containing no body 71 or a nitride phosphor 72 was formed. 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, which is on the first surface 10a of the light emitting element 10 and perpendicular to the first surface 10a of the light emitting element 10. The thickness T1 of the first layer 51 on the same line in the same direction was 76 μm, and the thickness T2 of the second layer 52 was 226 μm. The clear layer formed between the first layer 51 and the second layer 52 was contained in the first layer 51, and the thickness of only the clear layer could not be measured individually.

Example 15
The light emitting device 103 according to the embodiment shown in FIG. 3 was manufactured. As the light source 10, the same light emitting element as in Example 14 was used. The light emitting device 103 has a light emitting element, which is a light source 10, mounted on a substrate 200 by flip-chip. A first resin composition containing a fluoride phosphor 71 containing a silicone resin and a fluoride complex phosphor 71-1 and not containing an MGF phosphor was prepared. The first resin composition contains 150 parts by mass of the fluoride complex phosphor 71-1 with respect 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 was 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 with respect 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, as the nitride phosphor 72 contained in the second resin composition, two kinds of nitride phosphors 72-2 having different phosphor compositions and the nitride fluorescence Body 72-4 was used. The first resin composition is dropped so as to be in contact with at least a part of the light source 10, and the first resin composition is cured to form the first layer 51 containing the fluoride phosphor 71, and then the second. The second resin composition is dropped onto the first layer 51 so as to be in contact with at least a part of the first layer 51 using the resin composition, and the second resin composition is cured to cure the nitride phosphor. A second layer 52 containing 72 was formed. The obtained light emitting device 103 has a first layer 51 containing a fluoride phosphor 71, an intermediate region 53 in which a fluoride phosphor 71 and a nitride phosphor 72 are mixed, and a second layer containing a nitride phosphor 72. Includes 52. The first layer 51, the intermediate region 53, and the second layer 52 were continuous without boundaries of 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, which is on the first surface 10a of the light emitting element 10 and perpendicular to the first surface 10a of the light emitting element 10. The total thickness T1 + T2 of the first layer 51, the second layer 52, and the intermediate region 53 on the same line in the same direction was 301 μm. In the obtained light emitting device 103, since the first layer 51, the intermediate region 53, and the second layer 52 are continuously formed without boundaries, the thickness T1 of the first layer 51 and the thickness T2 of the second layer 52 are individually formed. Could not be measured.

Thickness of light emitting element, first layer, second layer and intermediate region Using a scanning electron microscope (SEM), cross-sectional SEM photographs of the light emitting device according to Examples 14 and 15 were obtained. In the cross-sectional SEM photograph, the thickness between the first surface 10a of the light source 10 mounted on the substrate 200 and the other second surface 10b facing the first surface 10a was measured as the thickness Te of the light emitting element 10. Further, the total thickness T1 + T2 of the first layer 51 and the second layer 52 was measured on the first surface 10a of the light emitting element 10 and on the same line in the direction perpendicular to the first surface 10a of the light emitting element 10.

Table 6 shows the evaluation results of the light emitting device according to Example 14 and Example 15.

In the light emitting device 102 according to the 14th embodiment and the light emitting device 103 according to the 15th embodiment, when the reference light emitting intensity is 1, the light emitting intensity ratio of the maximum light emitting peak wavelength is 7.4 or 7.8. Therefore, the blue light emitted from the light source 10 did not substantially escape from the light emitting device 102 or the light emitting device 103, and red light emission having high color purity and high luminous flux was obtained.

Reliability evaluation (relative luminous flux after continuous lighting)
The light emitting device according to Examples 14 and 15 was placed in a high temperature bath having a temperature of 85 ° C. and a humidity of 85%, continuously lit at 350 mA, and a total luminous flux measuring device using an integrating sphere was used for each elapsed time. Was measured. The luminous flux of the initial light emitting device that was lit at 350 mA before being placed in the high temperature bath was set to 100%, and the luminous flux for each elapsed time from the initial stage was expressed as a relative value. Further, the relative value of the luminous flux of the light emitting device after the lapse of 1018 hours with respect to the luminous flux of 100% of the initial light emitting device was calculated as the luminous flux maintenance rate. The results are shown in FIG.

The light emitting device according to Example 14 had a luminous flux maintenance rate of 42.8%, and the light emitting device according to Example 15 had a luminous flux maintenance rate of 72.0%. Luminous flux retention rate and as shown in FIG. 13, the light emitting device according to the fifteenth embodiment has a fluoride complex phosphor 71-1 and a nitride phosphor 72-4 and a nitride between the first layer and the second layer. An intermediate region in which the phosphors 72-2 are mixed is formed, and since each of the first layer, the intermediate region, and the second layer are continuously arranged without boundaries, the heat from the light source is easily dissipated to the outside and the heat dissipation property. It is considered that the luminous flux was improved and the luminous flux maintenance rate was increased. In the light emitting device according to the fifteenth embodiment, an intermediate region in which the fluoride complex phosphor 71-1, the nitride phosphor 72-4 and the nitride phosphor 72-2 coexist is provided between the first layer and the second layer. Therefore, the durability of the light emitting device is improved and the luminous flux maintenance rate is improved even when the light is continuously lit at a high temperature. In the light emitting device according to the fourteenth embodiment, since a clear layer in which no phosphor is present is formed between the first layer and the second layer, the light emitting device has an intermediate region between the first layer and the second layer. The luminous flux maintenance rate was lower than that of the light emitting device according to the above.

The light emitting device of the present disclosure can be suitably used for traffic lights, illuminated switches, various sensors, various indicators, small strobes, and the like.

10: Light source, 10a: First surface, 10b: Second surface, 20: First lead, 30: Second lead, 40: Molded body, 40r: Recessed portion, 42: Resin part, 43: Resin molded part, 43r: Recess, 50: Fluorescent member, 51: First layer, 52: Second layer, 53: Intermediate region, 54, 55, 56: Fluorescent layer, 60: Wire, 70: Fluorescent material, 71: Fluoride phosphor, 72 : Nitride phosphor ,, 80, 81: Reflective member, 90: Translucent body, 101, 102, 103, 104, 105, 106: Light emitting device, 200: Substrate.

Claims (17)

With semiconductor light emitting devices ,
At least one of a fluoride complex phosphor activated with manganese and a fluorogermanate phosphor activated with manganese that covers at least a part of the semiconductor light emitting element and converts the light emitted from the semiconductor light emitting element into wavelength. The first layer containing a fluoride fluorescent substance containing and a glass or a resin , wherein the content of the fluoride fluorescent substance with respect to 100 parts by mass of the glass or the resin is in the range of 150 parts by mass or more and 200 parts by mass or less. When,
It comprises a second layer that covers at least a part of the first layer and contains the semiconductor light emitting device and / or a nitride phosphor that wavelength-converts the light emitted from the first layer.
When the fluoride complex phosphor is contained and the fluorogermanate phosphor is not contained, the long wavelength side and the short wavelength from the center are centered on the maximum emission peak wavelength of the light emitting device in the emission spectrum of the light emitting device. The smallest emission intensity in the emission spectrum within the range of 15 nm on each side is used as the reference emission intensity.
When the fluorogermanate phosphor is contained, the emission spectrum in the emission spectrum of the light emitting device is within the range of 30 nm from the center to the long wavelength side and the short wavelength side, respectively, with the maximum emission peak wavelength of the light emitting device as the center. The smallest emission intensity is used as the reference emission intensity.
When the reference emission intensity is 1, the emission intensity ratio of the maximum emission peak wavelength of the semiconductor light emitting device is in the range of more than 0 and 0.1 or less, and is the maximum emission peak wavelength of the light emitting device . A light emitting device that emits red light with a light emission intensity ratio exceeding 2.8. The light emitting device according to claim 1, wherein when the reference light emitting intensity is 1, the light emitting intensity ratio of the maximum light emitting peak wavelength of the light emitting device in the light emitting spectrum of the light emitting device is 3.0 or more and 12.0 or less. .. The light emitting device according to claim 1 or 2, wherein the fluoride complex phosphor has a composition represented by the following formula (I).
A ₂ [M ^a _1-a Mn ^{4 +} _a F ₆ ] (I)
(In the formula (I), A is at least one element or ion selected from the group consisting of an alkali metal element and NH ₄₊ , and ^Ma is selected from the group consisting of ^a group 4 element and a group 14 element. It is at least one kind of element, and a is a number satisfying 0 <a <0.2.) The light emitting device according to any one of claims 1 to 3, wherein the fluorogermanate fluorescent substance has a composition represented by any of the following formulas (II-I) or (II-II).
3.5MgO ・ 0.5MgF2 ・_GeO2 : Mn ( _II -I)
(I-j) MgO · (j / 2) M ^b ₂ O ₃ · kmgF ₂ · mCaF ₂ · (1-n) GeO ₂ · (n / 2) Mc ₂ O ₃ : ^{zMn 4+} (II-II) )
(In formula (II-II), M ^b consists of the group consisting of Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. At least one element to be selected, Mc is at least one element selected from the group consisting of Al, Ga and In, and ⁱ , j, k, m, n and z are 2 ≦ i, respectively. ≤4, 0≤j <0.5, 0 <k <1.5, 0≤m <1.5, 0 <n <0.5, and 0 <z <0.05.) Any one of claims 1 to 4, wherein the nitride fluorophore is at least one selected from europium-activated nitride phosphors containing at least one of calcium and strontium, silicon, and aluminum in the composition. The light emitting device according to item 1. The light emitting device according to any one of claims 1 to 5, wherein the nitride phosphor has a composition represented by the following formula (III).
(Ca _1-s-t Sr _s Eu _t ) _x Al _u Si _v N _w (III)
(In formula (III), s, t, u, v, w and x are 0≤s <1, 0 <t <1.0, 0 <s + t <1.0, 0.8≤x≤1 respectively. .0, 0.8 ≤ u ≤ 1.2, 0.8 ≤ v ≤ 1.2, 1.9 ≤ u + v ≤ 2.1, 2.5 ≤ w ≤ 3.5.) The light emitting device according to any one of claims 1 to 6, wherein the semiconductor light emitting device has a light emitting peak wavelength in the range of 400 nm or more and 480 nm or less. The light emitting device according to any one of claims 1 to 7, wherein the semiconductor light emitting device is a GaN-based semiconductor light emitting device. Any of claims 1 to 8, wherein the second layer contains resin or glass, and the amount of the nitride phosphor with respect to 100 parts by mass of the resin or glass is in the range of 100 parts by mass or more and 200 parts by mass or less. The light emitting device according to item 1. The light emitting device according to claim 9, wherein the resin is at least one selected from the group consisting of a silicone resin, a modified silicone resin, an epoxy resin, and a modified epoxy resin. The second layer is arranged continuously with the first layer, and an intermediate region containing the fluoride phosphor, the nitride phosphor, and resin or glass between the first layer and the second layer. The light emitting device according to any one of claims 1 to 10, comprising the above. The second layer comprises a translucent body arranged so as to be in contact with at least a part of the first layer and arranged on the opposite side of the second layer from the side in contact with the first layer. The light emitting device according to any one of 1 to 11. The light emitting device according to claim 12, wherein the translucent body is made of a glass material. The light emission according to any one of claims 1 to 13, comprising a reflective member arranged so as to be in contact with a part of the semiconductor light emitting device and the first layer or a part of the second layer. Device. The light emitting device according to any one of claims 1 to 14, wherein the total thickness of the thickness T1 of the first layer and the thickness T2 of the second layer is larger than the thickness Te of the semiconductor light emitting device. When the thickness T2 of the second layer is 1, the thickness T1 of the first layer is within the range of 1.1 times or more and 5 times or less of the thickness T2 of the second layer, claims 1 to 15. The light emitting device according to any one of the above. When the thickness T2 of the second layer is 1, the thickness T1 of the first layer is within the range of 0.1 times or more and 1 times or less of the thickness T2 of the second layer, claims 1 to 15. The light emitting device according to any one of the above items.

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