TWI572065B - Phosphor and light emitting device - Google Patents

Description

Phosphor and illuminating device

The present invention relates to a phosphor used in an LED (Light Emitting Diode) and a light-emitting device using the LED.

The phosphor used in the white light-emitting device has a combination of β-SiAlON and a red-emitting phosphor (refer to Patent Document 1), and a red-emitting phosphor and a green-emitting phosphor having a specific color coordinate are combined. Phosphor (see Patent Document 2). The red phosphor has a technique of using a nitride phosphor called CASN or SCASN (see Patent Document 3), and is widely used. The red phosphor is used depending on the application. When the color rendering is important, a wavelength having a long wavelength of about 630 to 650 nm is used, and when the brightness is important, the peak wavelength is about 610 to 630 nm. The wavelength of the shorter wavelength product. It is also necessary to have high reliability in which the red phosphor is used at a high temperature or when the luminance is reduced with a long period of use.

Advanced technical literature Patent literature

Patent Document 1 Japanese Patent Laid-Open Publication No. 2007-180483

Patent Document 2 Japanese Patent Laid-Open Publication No. 2008-166825

Patent Document 3 Japanese Patent Laid-Open No. Hei 10-242513

The pursuit of a red phosphor that balances the color and brightness of each feature. The object of the present invention is to provide a non-destructive and reliable A red phosphor that is blended with a specific proportion of specific orange phosphors for improved color rendering and reliability, and a white phosphor that uses red phosphors with improved color rendering and reliability. Device.

The present invention is a phosphor comprising: a oxynitride phosphor (A) having a peak wavelength of 585 nm or more and 604 nm or less, a fluorescence intensity of 185% or more and 210% or less, and a nitride phosphor having a peak wavelength of 625 nm or more and 635 nm or less; (B) The blending ratio of the oxynitride phosphor (A) and the nitride phosphor (B) is 4% by mass or more and 12% by mass or less, respectively, and the oxynitride phosphor (A) and the nitride fluorite The total blending amount of the light body (B) is 10% by mass or more and 24% by mass or less.

When the blending ratio of the oxynitride phosphor (A) and the nitride phosphor (B) is a and b, respectively, it is preferable that the phosphor has a relationship of 0.33 ≦ a/b ≦ 3 . More preferably, the oxynitride phosphor (A) is α-SiAlON, and the nitride phosphor (B) is SCASN.

The invention derived from other viewpoints in the present invention is a light-emitting device including the above-described phosphor and an LED in which the phosphor is mounted on a light-emitting surface.

According to the present invention, it is possible to provide a phosphor which can improve the balance of color rendering and brightness under losslessness and reliability, and a white light-emitting device using the same.

The present invention relates to a phosphor having an oxynitride phosphor (A) having a peak wavelength of 585 nm or more and 604 nm or less, a fluorescence intensity of 185% or more and 210% or less, and a nitridation having a peak wavelength of 625 nm or more and 635 nm or less. The blend ratio of the phosphor (B), the oxynitride phosphor (A), and the nitride phosphor (B) is 4% by mass or more and 12% by mass or less, respectively, and the oxynitride phosphor (A) The total amount of the nitride phosphor (B) blended is 10% by mass or more and 24% by mass or less.

In the present invention, the brightness is improved by matching the orange phosphor and the red phosphor, and the brightness is improved by using the α-SiAlON in terms of the orange phosphor. Since α-SiAlON has high reliability and luminous efficiency, it is suitable for modulating high reliability red phosphor materials. Further, the fluorescence system of the peak wavelength of 650 nm or 630 nm which is often used in the red phosphor is close to the peak wavelength of α-SiAlON, and when the light is excited by blue light, the attenuation of the light beam due to the interaction is reduced. The combination is suitable. In the case of a nitride phosphor, there is a case where a peak wavelength of 620 nm or a peak in a shorter wavelength region is used in consideration of brightness, but in this case, a lack of a long-wavelength component causes a decrease in color rendering property. Therefore, even if a phosphor having a peak wavelength of 620 nm, 630 nm, or 650 nm is used alone as red, color rendering and brightness cannot be balanced, and a combination of a red phosphor of 630 nm and an α-SiAlON phosphor is used. Achieved.

When the peak wavelength of the oxynitride phosphor (A) is 585 nm or more and 604 nm or less, when it is combined with the nitride phosphor (B) having a peak wavelength of 625 nm or more and 635 nm or less, it is possible to improve the visibility while passing through The interaction reduces attenuation to suppress a decrease in luminous efficiency. If the peak wavelengths of the two are too close, the effect of improving the visual sensitivity of the nitride phosphor (B) is improved, that is, the effect of improving the brightness is small, and the luminescence of the oxynitride phosphor (A) is excessively alienated. Among them, used in nitride fluorescence The proportion of excitation of the body (B) becomes high, so that the luminous efficiency of the entire phosphor is lowered.

In the present invention, the blending ratio of the oxynitride phosphor (A) and the nitride phosphor (B) is suitably in the range of 1:3 to 3:1, but since the combination of the two is red The phosphor is used, so the optimum value will vary depending on the phosphor other than the red phosphor. In order to obtain the desired white light by excitation with blue light, the combination is combined with a green and/or yellow phosphor, but the total amount of the oxynitride phosphor (A) and the nitride phosphor (B) is 10 A range of up to 24% by mass is suitable. The amount of the oxynitride phosphor (A) or the nitride phosphor (B) to be blended is preferably 4% by mass or more and 12% by mass or less.

In the phosphor of the present invention, the reason why the fluorescent intensity of the oxynitride phosphor (A) is 185% or more and 210% or less is because the luminous efficiency of the article currently available is the highest. Further, the peak wavelength of the nitride phosphor (B) is 625 nm or more and 635 nm or less, which is the most widely used red nitride phosphor which is currently available. Both the oxynitride phosphor (A) and the nitride phosphor (B) phosphor have high reliability, and the reliability of the mixture is highly reliable because it is hardly affected by the interaction. Sex.

The fluorescence intensity of the phosphor is expressed by % in the relative value when the peak height of the standard sample (YAG, specifically, P46Y3 manufactured by Mitsubishi Chemical Corporation) is 100%. The measurement of the fluorescence intensity was carried out by the following method using a F-7000 spectrophotometer manufactured by Hitachi-hitec Co., Ltd.

<Measurement method>

1) Sample adjustment: The measurement sample or the standard sample is separately filled in a quartz sample cell, and then adjusted and measured interactively on the measuring machine. The filling system can be filled to about 3/4 of the height of the element at a relative filling density of about 35%.

2) Measurement: Excited with light of 455 nm, the maximum peak height of 300 nm to 800 nm was read. The measurement was performed 5 times, and the average value of 3 points was taken after subtracting the maximum value and the minimum value.

The peak wavelength of the phosphor is the wavelength of the maximum intensity at the time of fluorescence intensity measurement. For the measurement, the MCPD-7000 instantaneous multiplex measurement system manufactured by Otsuka Electronics Co., Ltd. is reflected by the HALMA Company product labsphere (registered trademark) Spectralon standard. The plate (99%, 2.0" x 2.0") was carried out as a standard sample. The measurement method was to fill a sample of Φ16 mm in the central portion of the slate made of alumina to a thickness of 3 mm, and then gently press it with a quartz plate to adjust it to wear, and excite it with light of 455 nm to read a peak height of 300 nm to 800 nm. The measured value of the peak wavelength is the average value of the measured value of the fifth time and the average value of the remaining three points after the minimum value is subtracted.

The oxynitride phosphor (A) in the present invention is an oxynitride phosphor having a peak wavelength of 585 nm or more and 604 nm or less and a fluorescence intensity of 185% or more and 210% or less. Specifically, there is α-SiAlON, and more specifically, among the ALON BRIGHT (registered trademark) of the Electrochemical Industry Co., Ltd., there are YL-C180, YL-C190, YL-C200, YL-595a, YL-595A', YL-595A, YL-595B, YL-600a, YL-600A', YL-600A, YL-600B. In the case of such currently available α-SiAlON, it is a phosphor material having a high peak intensity which has not been conventionally used.

The nitride phosphor (B) in the present invention is a nitride phosphor having a peak wavelength of 625 nm or more and 635 nm or less. Specifically, it is simply referred to as a red phosphor of SCASN, and more specifically, BR-102C or BR-102F of Mitsubishi Chemical Corporation, and ER6436 (peak wavelength of 630 nm) of Intematix Corporation. BR-102D of Mitsubishi Chemical Corporation, which is used for peak wavelength adjustment, ER6238 (peak wavelength 620 nm) of Intematix Co., Ltd., and ER6535 (peak wavelength 640 nm) of Intematix Co., Ltd., may be mixed in the nitride phosphor (B). ER6634 or BR-101A (peak wavelength 650nm) of Mitsubishi Chemical Corporation.

The oxynitride phosphor (A) and the nitride phosphor (B) are used together with a green or yellow phosphor for excitation of blue light, but are useful for utilizing the phosphor of the present invention. In the case of a high-luminance, high-reliability phosphor, it is preferred. Specifically, the green phosphor is a β-SiAlON that activates Eu or a LuAG (yttrium aluminum garnet) that activates Ce, and the yellow phosphor is YAG (yttrium aluminum garnet) or tantalum nitride (Lanthanum Silicon Nitride). (Mitsubishi Chemical Co., Ltd. trade name BY-201A), but it is also possible to apply these modified phosphors as a basic structure. Further, by adding a bismuth-based phosphor having a BOS (original citrate) as a basic structure to a green phosphor, color development can be improved, but the reliability of the citrate-based phosphor is not Good, so it is better to add less. The means for mixing the oxynitride phosphor (A) and the nitride phosphor (B), and the means for mixing the other phosphors, may be suitably mixed or mixed to a desired degree of mixing. Ground selection. Regarding the mixing means, it is premised on the fact that impurities are mixed and the shape or particle size of the phosphor is not significantly changed.

As described above, the invention derived from another viewpoint is a light-emitting device having a mixed phosphor and an LED in which the phosphor is mounted on a light-emitting surface. The phosphor to be mounted on the light-emitting surface of the LED is sealed by a sealing member. Regarding the sealing member, there are resin and glass; and the resin has a polyoxyl resin. Regarding the LED, it is preferable to select a red-emitting LED, a blue-emitting LED, and an LED that emits other colors in accordance with the final luminescent color; in the case of a blue-emitting LED, a GaN-based semiconductor It is preferable that the peak wavelength is 440 nm or more and 460 nm or less, and more preferably, the peak wavelength is 445 nm or more and 455 nm or less. The size of the light-emitting portion of the LED is preferably 0.5 mm or more. The LED wafer may be appropriately selected as long as it has such an area of the light-emitting portion, and is preferably 1.0 mm × 0.5 mm, more preferably 1.2 mm × 0.6 mm.

[Examples]

The embodiments of the present invention will be described in detail using the tables and comparative examples.

a phosphor shown in Table 1, which is an oxynitride phosphor (A), a nitride phosphor (B), and various comparative examples in the phosphor of the present invention, and Other phosphors. Among the oxynitride phosphors (A) of Table 1, only P2 is a phosphor that satisfies the conditions of a peak wavelength of 585 nm or more and 604 nm or less and satisfies the fluorescence intensity of 185% or more and 210% or less. Among the nitride phosphors (B) of Table 1, only P5 is a phosphor that satisfies the conditions of a peak wavelength of 625 nm or more and 635 nm or less.

The phosphors of the examples and the comparative examples were obtained by mixing these phosphors in the ratio of Table 2.

In the phosphor of the first embodiment, the phosphor of P2 as the oxynitride phosphor (A) is blended with 4.0% by mass of the phosphor of P5 of Table 1 as the nitride phosphor (B). The light body was blended with 6.0% by mass, and the phosphor of P7 of Table 1 as another phosphor was blended with 7.0% by mass of phosphor blend of P8. 83.0% by mass blender. The values of P1 to P9 in the constitution of the phosphor of Table 2 are the mass %. Regarding the mixing of the phosphors, a total of 2.5 g of the phosphors were mixed in a plastic bag, and a mixer (Tinky) was used together with 47.5 g of polyoxyxylene resin (OE 6656 of DOW CORNING TORAY Co., Ltd.). The stock system "defoaming Taro" ARE-310 (registered trademark) is mixed. In a+b and a/b of Table 2, the blending ratio of P1 in the example of the oxynitride phosphor (A) is a, and the blend of P5 in the example of the nitride phosphor (B) is used. The value when the ratio is set to b. Wherein b includes P4 and P6 in the case where the amount of P5 is not exceeded.

The phosphor is mounted on the LED, and the LED is placed on the bottom of the concave package body, and after the electrode is bonded to the substrate, the mixed phosphor is injected from the micro syringe. After the phosphor was mounted and cured at 120 ° C, it was subjected to post curing at 110 ° C for 10 hours and sealed. The LED is a light-emitting peak wavelength of 448 nm and a wafer size of 1.0 mm × 0.5 mm.

The evaluations shown in Table 2 are explained.

The initial evaluation of Table 2 is an evaluation using color rendering. The color rendering is evaluated by the color reproduction range, and is expressed by the area (%) of the NTSC specification ratio in the color coordinates. The larger the number, the higher the color rendering. The qualified conditions for the evaluation were 70% or more. In general, 72% or more is considered to be excellent in color reproducibility, and less than 68% is considered to have poor color reproducibility, which is a condition for general LED-TV.

The brightness of Table 2 is evaluated by the light beam (lm) at 25 °C. The measured value after passing a current of 100 mA for 10 minutes was taken. The eligibility conditions for the evaluation were 28.0 lm or more. Since this value varies depending on the measuring machine and conditions, The examples were compared and compared with the values set by (the lower limit of the examples) × 90%.

The high temperature characteristics of Table 2 were evaluated for the attenuation of the light beam at 25 °C. The value of the light beam at 50 ° C, 100 ° C, and 150 ° C was measured while setting the basis of 25 ° C to 100%. The acceptable conditions for the evaluation were 97% or more at 50 ° C, 95% or more at 100 ° C, and 90% or more at 150 ° C. Although this value is not a common specification value in the world, it is considered as a benchmark for high-reliability light-emitting components at this stage.

The long-term reliability of Table 2 was set at 85 ° C and 85% RH for 500 hours (hrs) and 2,000 hours, and the light beam at the time of drying at room temperature was taken out and measured, and the light beam at the initial value was set to 100%. Attenuation value. The qualified conditions for the evaluation were 96% or more at 500 hrs and 93% or more at 2,000 hrs. This is a value that cannot be achieved with a non-reliable phosphor.

As shown in Table 2, the examples of the present invention exhibited relatively good color reproducibility, beam values, and the attenuation of the light beam during long-term storage under high temperature or high temperature and high humidity was also small.

Comparative Examples 1, 3, 5, 6, 7, 8, and 9 have poor color reproducibility, while Comparative Examples 2, 4, and 10 have small beam values. Further, Comparative Examples 1, 2, and 7 in which a citrate-based phosphor (P7 in Table 1) was used in an excessive amount in excess of the blending amount of the oxynitride phosphor (A) or the nitride phosphor (B) In the case of 8th, it is a low-reliability LED package that is low in reliability and long-term reliability, and it cannot be expected to be suitable for products such as televisions or monitors.

[Industrial availability]

The phosphor of the present invention is used in a white light-emitting device. The white light-emitting device of the present invention can be used for a backlight of a liquid crystal panel, a lighting device, a signal device, and an image display device.

Claims (3)

A phosphor having α-SiAlON having a peak wavelength of 585 nm or more and 604 nm or less and a fluorescence intensity of 185% or more and 210% or less, and SCASN having a peak wavelength of 625 nm or more and 635 nm or less; the ratio of the α-SiAlON and the SCASN blending ratio The amount of the α-SiAlON and the SCASN in total is 10% by mass or more and 24% by mass or less, respectively, in an amount of 4% by mass or more and 12% by mass or less. The phosphor of claim 1, wherein when the blend ratio of the α-SiAlON and the SCASN is a and b by mass, respectively, the relationship has a relationship of 0.33 ≦ a/b ≦ 3 . A light-emitting device comprising the phosphor of the first or second aspect of the patent application, and an LED obtained by mounting the phosphor on a light-emitting surface.