Semiconductor light-emitting device

Abstract

To provide a semiconductor light-emitting device that suppresses color deviation of white light due to temperature in the semiconductor light-emitting device.SOLUTION: A semiconductor light-emitting device that emits white light has: a substrate; a semiconductor light-emitting element having a light emission peak at a wavelength of 430 nm to 480 nm provided in the substrate; and a transparent material including a plurality of wavelength conversion materials that convert the wavelength of light emitted from the semiconductor light-emitting element. In the emission spectrum of white light, the absolute value of the difference between a change by temperature in the emission spectrum at a wavelength of 500 nm or more and less than 605 nm and a change by temperature in the emission spectrum at wavelengths of 605 nm or more and less than 650 nm is reduced.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a semiconductor light emitting device comprising a semiconductor light emitting element and a wavelength converting material. [Background technology]

[0002] 2. Description of the Related Art Semiconductor light emitting devices that combine an LED (semiconductor light emitting element) and a phosphor to emit white light have become widely used for a variety of purposes due to their long life and low energy consumption.

[0003] In the field of general lighting among the application areas of semiconductor light emitting devices, good color rendering is required in addition to low energy consumption. Patent Document 1 discloses a light receiving and emitting medium including a broadband spectrum red phosphor and a narrowband spectrum red phosphor as a semiconductor light emitting device that achieves both energy efficiency and color rendering. As a narrow-band spectrum red phosphor, for example, K2SiF6:Mn 4+ A fluoride phosphor represented by the following formula is known (see Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 8,921,875 [Patent Document 2] JP 2010-209311 A Summary of the Invention [Problem to be solved by the invention]

[0005] The inventors of the present invention further investigated a semiconductor light-emitting device that can achieve both energy efficiency and color rendering by using a fluoride phosphor, and came up with a new problem that the white light emitted from the semiconductor light-emitting device varies in chromaticity depending on the temperature inside the semiconductor light-emitting device.The present invention aims to provide a semiconductor light-emitting device that suppresses the variation in chromaticity of the white light that can occur in a semiconductor light-emitting device that uses a fluoride phosphor due to the temperature inside the semiconductor light-emitting device. [Means for solving the problem]

[0006] In order to solve the above problems, the inventors have confirmed the change in the emission characteristics of wavelength converting materials due to temperature changes, and have found that, while fluoride phosphors have extremely high stability in the emission characteristics due to temperature changes, other wavelength converting materials have materials whose emission characteristics change greatly due to temperature changes. In addition, when the spectrum of white light emitted by a semiconductor light emitting device containing a fluoride phosphor as a wavelength converting material is confirmed, it has been found that there is a wavelength region in which the emission characteristics change greatly due to temperature changes. Based on these findings, the researchers carried out intensive research and completed a semiconductor light-emitting device that suppresses deviations in the chromaticity of white light caused by temperature changes within the device.

[0007] The present invention includes the following aspects. [1] A substrate; a semiconductor light-emitting element having an emission peak at a wavelength of 430 nm to 480 nm provided on the substrate; a light-transmitting material including a plurality of wavelength conversion materials that convert a wavelength of light emitted from the semiconductor light-emitting element, In the emission spectrum of the white light, The first region is wavelengths between 380 nm and 500 nm. The second region is wavelengths of 500 nm or more and less than 605 nm. The third region is wavelengths between 605 nm and 650 nm. The fourth region is defined as the wavelength range of 650 nm to 780 nm. the wavelength converting material includes at least a phosphor A having an emission peak in the second region, a fluoride phosphor having an emission peak in the third region, and a phosphor B having an emission peak in a wavelength region of 590 nm or more and 780 nm or less; The change in the integral value of the spectral radiant flux of the white light in the second region when the operating temperature of the semiconductor light emitting device is changed from 25° C. to 85° C. is ΔS2 (%); When the operating temperature of the semiconductor light emitting device is changed from 25° C. to 85° C., the change in the integral value of the spectral radiant flux of the white light in the third region is ΔS3 (%). When the color temperature of the white light is 3000K or less, the value of |ΔS2-ΔS3| is 8% or less; In the range where the color temperature of the white light is higher than 3000K, the value of |ΔS2-ΔS3| is 12% or less. Semiconductor light emitting device. [2] A substrate; a semiconductor light-emitting element having an emission peak at a wavelength of 430 nm to 480 nm provided on the substrate; a light-transmitting material including a plurality of wavelength conversion materials that convert a wavelength of light emitted from the semiconductor light-emitting element, The wavelength converting material includes at least a phosphor A having an emission peak at a wavelength of 500 nm or more and less than 605 nm, a fluoride phosphor having an emission peak at a wavelength of 605 nm or more and less than 650 nm, and a phosphor B having an emission peak at a wavelength of 590 nm or more and 780 nm or less, The phosphor A and the phosphor B each have a change (%) of 8% or more in the integral value of the spectral radiant flux of the fluorescence emitted from the phosphor when the operating temperature is changed from 25°C to 85°C, When the operating temperature of the semiconductor light emitting device is changed from 25°C to 85°C, the amount of chromaticity change of the white light on the chromaticity diagram is within 3 steps of a MacAdam ellipse. Semiconductor light emitting device. [3] In the emission spectrum of the white light, the integral value of the spectral radiant flux in the wavelength region of 380 nm or more and 780 nm or less is defined as S, and the integral value of the spectral radiant flux in the fourth region is defined as S A When S A The semiconductor light emitting device according to [1] or [2], wherein the value of / S is 0.06 or more and 0.15 or less. [4] The semiconductor light emitting device according to any one of [1] to [3], wherein the phosphor A is a garnet phosphor. [5] The semiconductor light emitting device according to any one of [1] to [4], wherein the phosphor A is a LuAG phosphor. [6] The semiconductor light emitting device according to any one of [1] to [5], wherein the phosphor B is a SCASN phosphor. [7] The semiconductor light emitting device according to any one of [1] to [6], wherein the fluoride phosphor is a KSF phosphor. [8] The semiconductor light emitting device according to any one of [1] to [7], wherein the white light has a color rendering index Ra of 90 or more. [9] The semiconductor light emitting device according to any one of [1] to [8], wherein the blending amount of the fluoride phosphor in the translucent material relative to the weight of the transmissive material is 35 wt % or less.

[10] The semiconductor light emitting device according to any one of [1] to [9], wherein the phosphor B has a peak wavelength of 620 nm or more. Effect of the Invention

[0008] According to the present invention, it is possible to provide a semiconductor light emitting device in which deviation in chromaticity of white light due to temperature inside the semiconductor light emitting device is suppressed. [Brief description of the drawings]

[0009] [Figure 1] 1 is a graph showing the emission spectrum at room temperature (25° C., solid line) and the emission spectrum at high temperature (85° C., dashed line) of the LuAG phosphor used in the examples. [Diagram 2] 1 is a graph showing the emission spectrum at room temperature (25° C., solid line) and the emission spectrum at high temperature (85° C., dashed line) of a YAG phosphor used in an example. [Diagram 3] 1 is a graph showing the emission spectrum at room temperature (25° C., solid line) and the emission spectrum at high temperature (85° C., dashed line) of the KSF phosphor used in the examples. [Figure 4]1 is a graph showing the emission spectrum at room temperature (25° C., solid line) and the emission spectrum at high temperature (85° C., dashed line) of the SCASN phosphor used in the examples. [Diagram 5] 1 is a graph showing the emission spectrum at room temperature (25° C., solid line) and the emission spectrum at high temperature (85° C., dashed line) of the SCASN phosphor used in the examples. [Figure 6] 2 is a graph showing the emission spectrum at room temperature (25° C., solid line) and the emission spectrum at a high temperature (85° C., dashed line) of the white light emitting device 1 used in the examples (corresponding to the examples). [Figure 7] 1 is a graph showing the emission spectrum at room temperature (25° C., solid line) and the emission spectrum at a high temperature (85° C., dashed line) of the white light emitting device 8 used in the example (corresponding to a comparative example). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will be described in more detail below, but the scope of the invention is not limited to the specific embodiment. In addition, the numerical range represented by "X to Y" in this specification means a numerical range including X as the lower limit and Y as the upper limit. When the numerical range is described in stages, the upper limit and the lower limit of each numerical range can be arbitrarily combined.

[0011] One aspect of the present invention is a semiconductor light-emitting device that emits white light, comprising: a base; a semiconductor light-emitting element provided on the base and having an emission peak at a wavelength of 430 nm to 480 nm; and a light-transmitting material that includes a plurality of wavelength conversion materials that convert the wavelength of light emitted from the semiconductor light-emitting element.

[0012] The base may be any one capable of arranging the semiconductor light emitting element, typically a plate-shaped substrate, but is not particularly limited thereto. One or more semiconductor light emitting elements are arranged on the base, and a plurality of semiconductor light emitting elements may be arranged in an array or in a plane. The semiconductor light emitting element arranged on the base is connected to a power source and is in a state capable of emitting a predetermined light. The semiconductor light emitting element disposed on the base is sealed with a light-transmitting material containing a plurality of wavelength conversion materials that convert the wavelength of light emitted from the semiconductor light emitting element. With this configuration, the wavelength of part of the light emitted from the semiconductor light emitting element is converted by the wavelength conversion materials dispersed in the light-transmitting material, and the light becomes light with a wavelength different from that of the semiconductor light emitting element.

[0013] The semiconductor light emitting element is a blue semiconductor light emitting element having an emission peak at a wavelength of 430 nm to 480 nm. A semiconductor light emitting element other than the blue semiconductor light emitting element, for example a green semiconductor light emitting element or a red semiconductor light emitting element, may be used in combination.

[0014] The light-transmitting material functions as a wavelength conversion member by including a plurality of wavelength conversion materials that convert the wavelength of light emitted from the semiconductor light-emitting element. As the light-transmitting material, a resin having light-transmitting properties can be used, and typically, a silicone resin or an epoxy resin is used. Furthermore, the wavelength conversion material included in the light-transmitting material is typically a phosphor.

[0015] In this embodiment, the semiconductor light emitting device emits white light. The emitted white light is obtained by combining phosphor A having an emission peak in the second region and fluoride having an emission peak in the third region, where the emission spectrum is defined as a first region having a wavelength of 380 nm or more and less than 500 nm, a second region having a wavelength of 500 nm or more and less than 605 nm, a third region having a wavelength of 605 nm or more and less than 650 nm, and a fourth region having a wavelength of 650 nm or more and less than 780 nm. and phosphor B having an emission peak in the wavelength region of 590 nm or more and 780 nm or less.

[0016] Phosphor A is a phosphor having an emission peak in the second region, that is, a wavelength region of 500 nm or more and less than 605 nm. Phosphor A is preferably a green phosphor that emits fluorescence in the green wavelength region. Phosphors having an emission peak in the second region other than green phosphors, such as a yellow phosphor that emits fluorescence in the yellow wavelength region or an orange phosphor that emits fluorescence in the orange wavelength region, may also be used.

[0017] An example of a green phosphor is Ce. 3+ Aluminate activated with Eu 2+ Activated alkaline earth silicate, Eu 2+ Activated alkaline earth silicon oxynitride, Ce 3+ Examples of such green phosphors include those based on silicon nitride and using fluorine as an activator. Among these, garnet phosphors having a garnet structure, including YAG and LuAG, are preferred, and LuAG phosphors represented by the following general formula (I) are preferred. Lu a (Ce,Tb,Y) b (Ga, Sc) c Al d O e (I) In general formula (I), a, b, c, d, and e satisfy a+b=3, 0≦b≦0.2, 4.5≦c+d≦5.5, 0≦c≦2.6, and 10.8≦e≦13.4.

[0018] The fluoride phosphor is a phosphor having an emission peak in the third region, that is, the wavelength region of 605 nm or more and less than 650 nm. 4+ A is an activator and an alkali metal fluoro complex is used as the host crystal. 2+x M y Mn z F n (A is Na and / or K; M is Si and Al; -1≦x≦1 and 0.9≦y+z≦1.1 and 0.001≦z≦0.4 and 5≦n≦7). Specific examples include K2SiF6:Mn (called KSF phosphor) and Na2SiF6:Mn, and the KSF phosphor is preferred.

[0019] A fluoride phosphor is a phosphor whose fluorescence spectrum has a small half-width, which is usually 1 nm or more, and may be 2 nm or more, and is usually 15 nm or less, and may be 10 nm or less.

[0020] Phosphor B is a phosphor having an emission peak in the wavelength region of 590 nm or more and 780 nm or less. Phosphor B is preferably a red phosphor that emits fluorescence in the red wavelength region. Phosphors other than red phosphors, such as orange phosphors that emit fluorescence in the orange wavelength region, may also be used.

[0021] Examples of red to orange phosphors include Eu 2+ Examples of phosphors include those using as an activator a phosphor having a crystal matrix made of alkaline earth silicon nitride, α-sialon, or alkaline earth silicate. Among these, the SCASN phosphor represented by the following general formula (II) is preferred. (Ca,Sr,Ba)AlSiN3:Eu...(II)

[0022] Alternatively, a blue phosphor having an emission peak in the first region, that is, in a wavelength region of 380 nm or more and less than 500 nm, may be used as the phosphor.

[0023] The amount of phosphor in the light-transmitting material is not particularly limited, and can be appropriately set by a person skilled in the art so that white light having a desired color temperature is emitted, but in this embodiment, the amount of fluoride phosphor blended is preferably 35 wt% or less, more preferably 30 wt% or less, relative to the weight of the light-transmitting material. There is no lower limit, but it is usually 5 wt% or more, and may be 10 wt% or more. Fluoride phosphors have excellent stability in their light-emitting characteristics with temperature. Therefore, in a light-emitting device containing a fluoride phosphor, other phosphors are less susceptible to changes in light-emitting characteristics with temperature. When the objective is large and the blending amount is large, the chromaticity of white light is likely to shift due to temperature, and the present embodiment, which can suppress the chromaticity shift due to temperature, is suitably applied when the blending amount of the fluoride phosphor is within the above-mentioned range.

[0024] The light-emitting device of this embodiment emits white light. The white light may be incandescent white light, warm white light, or daylight white light, and the color temperature is not particularly limited. It is usually 1600K or more, may be 2000K or more, or may be 2400K or more. It is usually 12000K or less, may be 7000K or less, or may be 6500K or less.

[0025] The light emitting device of this embodiment is a light emitting device in which the chromaticity shift of the white light due to temperature is suppressed. The inventors confirmed the change in the luminous characteristics of the wavelength conversion material due to the temperature change, and found that the fluoride phosphor had extremely high stability of the luminous characteristics due to temperature change. In addition, when the emission spectrum of the white light emitted by a semiconductor light emitting device containing a fluoride phosphor as a wavelength conversion material was confirmed, it was found that there is a wavelength region in which the luminous characteristics change greatly due to temperature change. And, in the emission spectrum of the white light emitted from the light emitting device, the absolute value of the difference between the amount of change in the emission spectrum due to temperature in the second region and the amount of change in the emission spectrum due to temperature in the third region is small, and it was found that the chromaticity shift of the white light due to temperature change is suppressed.

[0026] That is, when the change in the integral value of the spectral radiant flux of the white light in the second region when the operating temperature of the semiconductor light-emitting device is changed from 25°C to 85°C is ΔS2 (%), and the change in the integral value of the spectral radiant flux of the white light in the third region when the operating temperature of the semiconductor light-emitting device is changed from 25°C to 85°C is ΔS3 (%), the chromaticity shift of the white light due to temperature change is suppressed when the value of |ΔS2-ΔS3| is 8% or less when the color temperature of the white light is 3000K or less, and the value of |ΔS2-ΔS3| is 12% or less when the color temperature of the white light is in the range higher than 3000K.

[0027] When the color temperature of the white light is 3000K or less, i.e., when it is incandescent white light, the amount of change in the emission spectrum in the second and third regions due to temperature has a relatively large effect on chromaticity shift, so the absolute value of the difference must be 8% or less.When the color temperature of the white light is greater than 3000K, i.e., when it is warm white or daylight white light, the amount of change in the emission spectrum in the second and third regions due to temperature has a relatively small effect on chromaticity shift, so the absolute value of the difference must be 12% or less.

[0028] In the semiconductor light emitting device of this embodiment, the integral value of the spectral radiant flux in the wavelength region of 380 nm or more and 780 nm or less in the emission spectrum of white light is defined as S, and the integral value of the spectral radiant flux in the fourth region is defined as S A Then, S A It is preferable that the value of / S is 0.06 or more and 0.15 or less. By the integral value of the emission spectrum of the fourth region, i.e., the red region, being in the above range, it is possible to improve the color rendering of the white light while suppressing the chromaticity deviation. In this embodiment, the color rendering evaluation index Ra of the white light emitted from the semiconductor light emitting device is preferably 90 or more, and more preferably 95 or more.

[0029] As described above, in the emission spectrum of white light from the semiconductor light emitting device, the absolute value of the difference between the amount of change in the emission spectrum due to temperature in the second region and the amount of change in the emission spectrum due to temperature in the third region is reduced, thereby suppressing the chromaticity shift of the white light due to temperature change. Specifically, when the operating temperature of the semiconductor light emitting device is changed from 25°C to 85°C, the amount of chromaticity change on the chromaticity diagram of the white light can be kept within 3 steps of the MacAdam ellipse, and preferably within 2 steps.

[0030] The MacAdam ellipse is described in, for example, JP 2020-198345 A and JP 2019-1255 A. It is also used in No. 82 and other publications, and shows the range on the CIExy chromaticity diagram where a person with normal color vision cannot distinguish between colors based on the results of color matching experiments, and is an ellipse that shows the standard deviation of discrimination fluctuation for a specific center color on the CIExy chromaticity diagram. In this embodiment, the chromaticity deviation due to the temperature of white light was determined using the following criteria.

[0031] <Definition of criteria> On the CIE chromaticity coordinates, the distances of the farthest points from the center of the MacAdam ellipse corresponding to each step are defined as Cx and Cy for the x and y coordinates, respectively. The square root of the sum of the products of Cx and Cy is defined as the maximum value of each step range. Under this definition, it is preferable that the change in chromaticity when the operating temperature of the light-emitting device is changed from 25°C to 85°C is within 3 steps, and more preferably within 2 steps.

[0032] As described above, in order to obtain a semiconductor light-emitting device in which the amount of chromaticity change on the chromaticity diagram of white light when the operating temperature of the semiconductor light-emitting device is changed from 25°C to 85°C is within 3 steps of the MacAdam ellipse, it has been conceived that this can be easily achieved by using a constant amount of phosphor A and phosphor B, respectively, such that the amount of change (%) in the integrated value of the spectral radiant flux of the fluorescence emitted from the phosphors when the operating temperature is changed from 25°C to 85°C.

[0033] That is, another aspect of the present invention is a semiconductor light-emitting device that emits white light, comprising: a base; a semiconductor light-emitting element that is provided on the base and has an emission peak at a wavelength of 430 nm to 480 nm; and a light-transmitting material that contains a plurality of wavelength conversion materials that convert the wavelength of light emitted from the semiconductor light-emitting element, The wavelength converting material includes at least a phosphor A having an emission peak at a wavelength of 500 nm or more and less than 605 nm, a fluoride phosphor having an emission peak at a wavelength of 605 nm or more and less than 650 nm, and a phosphor B having an emission peak at a wavelength of 590 nm or more and 780 nm or less, In the emission spectrum of the white light, The first region is wavelengths between 380 nm and 500 nm. The second region is wavelengths of 500 nm or more and less than 605 nm. The third region is wavelengths between 605 nm and 650 nm. The fourth region is defined as the wavelength range of 650 nm to 780 nm. the wavelength converting material includes at least a phosphor A having an emission peak in the second region, a fluoride phosphor having an emission peak in the third region, and a phosphor B having an emission peak in a wavelength region of 590 nm or more and 780 nm or less; The change in the integral value of the spectral radiant flux of the fluorescence emitted by the phosphor A when the operating temperature of the phosphor A is changed from 25° C. to 85° C. is defined as ΔSelmtA (%), When the operating temperature of the phosphor B is changed from 25° C. to 85° C., the change in the integral value of the spectral radiant flux of the fluorescence emitted by the phosphor B is ΔSelmtB (%). The phosphor A has a ΔSelmt A (%) is 8% or more, The phosphor B has a ΔSelmt B (%) is 8% or more, The semiconductor light emitting device is one in which the amount of chromaticity change on the chromaticity diagram of the white light when the operating temperature of the semiconductor light emitting device is changed from 25° C. to 85° C. is within 3 steps of a MacAdam ellipse.

[0034] The change amount ΔSelmt A (%) is more preferably 8% or more and 20% or less, and even more preferably 8% or more and 15% or less, and the change amount ΔSelmt B (%) is more preferably 8% or more and 20% or less, and even more preferably 8% or more and 15% or less.

[0035] In another aspect of the present invention, the semiconductor light emitting device can be identified based on the change in the light emission characteristics of the phosphor caused by a change in temperature. That is, a substrate and a light emitting diode having an emission peak at wavelengths of 430 nm to 480 nm provided on the substrate and a light-transmitting material including a plurality of wavelength conversion materials that convert the wavelength of light emitted from the semiconductor light-emitting element, the light emission spectrum of the white light being: The first region is wavelengths between 380 nm and 500 nm. The second region is wavelengths of 500 nm or more and less than 605 nm. The third region is wavelengths between 605 nm and 650 nm. The fourth region is defined as the wavelength range of 650 nm to 780 nm. the wavelength converting material includes at least a phosphor A having an emission peak in the second region, a fluoride phosphor having an emission peak in the third region, and a phosphor B having an emission peak in a wavelength region of 590 nm or more and 780 nm or less; The change in the integral value of the spectral radiant flux of the fluorescence emitted by the phosphor A when the operating temperature of the phosphor A is changed from 25°C to 85°C is defined as ΔSelmt A (%)year, The amount of change in the integral value of the spectral radiant flux of the fluorescence emitted by the phosphor B when the operating temperature of the phosphor B is changed from 25° C. to 85° C. is defined as ΔSelmt B When expressed as (%), When the color temperature of the white light is 3000K or less, |ΔSelmt A -ΔSelmt B The value of | is 6% or less, In the range where the color temperature of the white light is higher than 3000K, |ΔSelmt A -ΔSelmt B The semiconductor light emitting device has a | value of 7% or less.

[0036] Furthermore, in still another aspect of the present invention, it is possible to provide a method for designing a semiconductor light emitting device that suppresses deviation in chromaticity of white light due to temperature inside the semiconductor light emitting device. That is, a substrate and a semiconductor light-emitting element having an emission peak at a wavelength of 430 nm to 480 nm provided on the substrate; a light-transmitting material including a plurality of wavelength conversion materials that convert a wavelength of light emitted from the semiconductor light-emitting element, In the emission spectrum of the white light, The first region is wavelengths between 380 nm and 500 nm. The second region is wavelengths of 500 nm or more and less than 605 nm. The third region is wavelengths between 605 nm and 650 nm. The fourth region is defined as the wavelength range of 650 nm to 780 nm. the wavelength converting material includes at least a phosphor A having an emission peak in the second region, a fluoride phosphor having an emission peak in the third region, and a phosphor B having an emission peak in a wavelength region of 590 nm or more and 780 nm or less; The change in the integral value of the spectral radiant flux of the white light in the second region when the operating temperature of the semiconductor light emitting device is changed from 25° C. to 85° C. is ΔS2 (%); When the operating temperature of the semiconductor light emitting device is changed from 25° C. to 85° C., the change in the integral value of the spectral radiant flux of the white light in the third region is ΔS3 (%). When the color temperature of the white light is 3000K or less, the value of |ΔS2-ΔS3| is 8% or less; This is a method for designing a semiconductor light emitting device, in which the wavelength converting material is adjusted so that the value of |ΔS2−ΔS3| is 12% or less when the color temperature of the white light is in a range higher than 3000K.

[0037] In the above-mentioned method for designing a semiconductor light-emitting device, the wavelength conversion material can be adjusted mainly by selecting phosphor A and phosphor B. Specifically, the amount of change in the integral value of the spectral radiant flux of the fluorescence emitted by phosphor A when the operating temperature of phosphor A is changed from 25° C. to 85° C. is defined as ΔSelmt A (%), and the amount of change in the integral value of the spectral radiant flux of the fluorescence emitted by the phosphor B when the operating temperature of the phosphor B is changed from 25° C. to 85° C. is ΔSelmt B (%), ΔSelmt A It is preferable to use phosphor A having a value of 8% or more and 20% or less, and ΔSelmt B It is preferable to use phosphor B having a content of 8% or more and 20% or less. A-ΔSelmt B It is preferable to use phosphors A and B in which the value of |ΔSelmt is 6% or less, and in the range in which the color temperature of the white light is higher than 3000 K, A -ΔSelmt B It is preferable to use phosphors A and B such that the | value is 7% or less.

[0038] The semiconductor light emitting device according to the present embodiment emits white light and is suitable for use as general lighting since deviations in chromaticity due to operating temperature are suppressed, but may be used for other purposes. EXAMPLES

[0039] <Example> White light emitting devices 1 to 9 (COB: chip-on-board type) were created as shown in Table 1, and various data were obtained when the operating temperature was changed from 25°C to 85°C. Note that the weight (wt%) of KSF in Table 1 is the weight relative to the total amount of translucent material excluding phosphor. Specifically, a blue semiconductor light-emitting element (peak emission wavelength: approximately 450 nm) was placed on a base, and a light-transmitting material (silicone resin) containing the phosphor shown in Table 1 was placed on top of it to produce the device. Note that the chromaticity change in Table 1 indicates the MacAdam ellipse size within which the chromaticity change occurs when the operating temperature is changed from 25°C to 85°C. The emission wavelengths of the phosphors used in the examples are as follows: LuAG: Solid line in Figure 1 YAG: Solid line in Figure 2 KSF: Solid line in Figure 3 SCASN: Solid line in Figure 4 or solid line in Figure 5

[0040] [Table 1]

[0041] Looking at the results of the examples, it was found that when the chromaticity shift of the white light emitted from the light-emitting device relative to the operating temperature is small, the difference in intensity change between the second and third regions is small, that is, the value of |ΔS2-ΔS3| is small. It was also found that as the color temperature increases, the range of the value of |ΔS2-ΔS3| when the chromaticity shift falls within the preferable range also becomes larger. The temperature changes in the emission spectra of the white light emitting device 1 and the white light emitting device 8 are shown in Figures 6 and 7. As can be seen from Figure 6, the semiconductor light emitting device with small chromaticity shift due to temperature has a large amount of spectral change in the second region, but also has a large amount of spectral change in the third region, and the difference in intensity change between the two regions is small. On the other hand, as can be seen from Figure 7, the semiconductor light emitting device with large chromaticity shift due to temperature has a large amount of spectral change in the second region, but also has a small amount of spectral change in the third region, and the difference in intensity change between the two regions is large.

[0042] This time, YAG and LuAG were used as phosphors with emission peaks in the second region. These phosphors are widely used in semiconductor light-emitting devices. Analysis of the results showed that samples using LuAG tended to have smaller chromaticity shifts due to operating temperature than samples using YAG. The characteristics of YAG and LuAG were confirmed, and the difference in the amount of change in emission intensity in the second region due to operating temperature was confirmed. The amount of change in emission intensity in the second region was 14.9% and 11.9% for YAG and LuAG, respectively. Since the amount of change in emission intensity in the second region is small due to operating temperature, which is derived from fluoride phosphors, it is better for the amount of change in emission intensity in the second region to be small, so it can be estimated that the chromaticity deviation of the light-emitting device is reduced more when LuAG is used than when YAG is used.

[0043] Using fluoride phosphors and SCASN as phosphors with emission peaks in the wavelength range of 590nm to 780nm, we investigated the relationship between chromaticity shift due to temperature changes in light-emitting devices and SCASN.When using SCASN with a peak wavelength of 620nm or more and SCASN with a peak wavelength of less than 620nm, we found that the one using SCASN with a longer peak wavelength showed a smaller chromaticity shift of white light and a more favorable tendency. The decrease in emission intensity with respect to operating temperature is greater for SCASN than for fluoride phosphors, and the decrease in emission due to temperature changes is particularly large for SCASN around the emission peak wavelength. Since fluoride phosphors have a sharp emission spectrum, if the decrease in emission intensity is large in the area that overlaps with the emission region of fluoride phosphors and in the longer wavelength region, the decrease is balanced in the spectrum of the entire light-emitting device, and the chromaticity deviation is reduced.

Claims

1. A substrate; a semiconductor light-emitting element provided on the substrate and having an emission peak at a wavelength of 430 nm to 480 nm; a light-transmitting material including a plurality of wavelength conversion materials that convert a wavelength of light emitted from the semiconductor light-emitting element, In the emission spectrum of the white light, A first region is a wavelength of 380 nm or more and less than 500 nm. A second region is a wavelength of 500 nm or more and less than 605 nm. A third region is a wavelength of 605 nm or more and less than 650 nm. A wavelength range of 650 nm or more and 780 nm or less is defined as a fourth region, The wavelength converting material includes at least a phosphor A having an emission peak in the second region, a fluoride phosphor having an emission peak in the third region, and a phosphor B having an emission peak in a wavelength region of 590 nm or more and 780 nm or less, The amount of change in the integral value of the spectral radiant flux of the white light in the second region when the operating temperature of the semiconductor light emitting device is changed from 25° C. to 85° C. is represented by ΔS ２ (%)year, The amount of change in the integral value of the spectral radiant flux of the white light in the third region when the operating temperature of the semiconductor light emitting device is changed from 25° C. to 85° C. is represented by ΔS ３ When expressed as (%), When the color temperature of the white light is 3000 K or less, |ΔS ２ -ΔS ３ The value of | is 8% or less, In the range where the color temperature of the white light is higher than 3000 K, |ΔS ２ -ΔS ３ The value of | is 12% or less; Semiconductor light emitting device.

2. A substrate; a semiconductor light-emitting element provided on the substrate and having an emission peak at a wavelength of 430 nm to 480 nm; a light-transmitting material including a plurality of wavelength conversion materials that convert a wavelength of light emitted from the semiconductor light-emitting element, The wavelength conversion material includes at least a phosphor A having an emission peak at a wavelength of 500 nm or more and less than 605 nm, a fluoride phosphor having an emission peak at a wavelength of 605 nm or more and less than 650 nm, and a phosphor B having an emission peak at a wavelength of 590 nm or more and 780 nm or less, For each of the phosphors A and B, the change (%) in the integral value of the spectral radiant flux of the fluorescence emitted from the phosphors when the operating temperature is changed from 25° C. to 85° C. is 8% or more; When the operating temperature of the semiconductor light emitting device is changed from 25° C. to 85° C., the amount of chromaticity change of the white light on the chromaticity diagram is within 3 steps of a MacAdam ellipse. Semiconductor light emitting device.

3. In the emission spectrum of the white light, an integral value of the spectral radiant flux in a wavelength region of 380 nm or more and 780 nm or less is defined as S, and an integral value of the spectral radiant flux in the fourth region is defined as S Ａ When S Ａ 3. The semiconductor light emitting device according to claim 1, wherein the value of / S is 0.06 or more and 0.15 or less.

4. 3. The semiconductor light emitting device according to claim 1, wherein said phosphor A is a garnet phosphor.

5. 3. The semiconductor light emitting device according to claim 1, wherein the phosphor A is a LuAG phosphor.

6. The semiconductor light emitting device according to claim 1 , wherein the phosphor B is a SCASN phosphor.

7. 3. The semiconductor light emitting device according to claim 1, wherein the fluoride phosphor is a KSF phosphor.

8. 3. The semiconductor light emitting device according to claim 1, wherein the white light has a color rendering index Ra of 90 or more.

9. 3. The semiconductor light emitting device according to claim 1, wherein the mixing ratio of said fluoride phosphor in said light transmitting material is 35 wt % or less with respect to the weight of said light transmitting material.

10. 3. The semiconductor light emitting device according to claim 1, wherein said phosphor B has a peak wavelength of 620 nm or more.

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