JP2007234817A - Light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting device capable of reducing an angle color difference and obtaining a color temperature of not more than 5,000 K easily in the light-emitting device having a recess with a relatively small diameter or depth for reducing the angle color difference easily. <P>SOLUTION: The light-emitting device comprises: a substrate having a recess where the diameter of an open end is not less than 1.0 mm and not more than 2.0 mm; a light-emitting element that is arranged in the recess and emits blue light; a resin layer that is formed in the recess so that the light-emitting element is covered, contains a phosphor that is excited by blue light emitted from the light-emitting element, emits at least yellow light, and contains a phosphor where coating volume in the recess is not more than 5 mm<SP>3</SP>; and a reflection layer that is formed at least at one part of the inner surface of the recess, where the reflection factor of light having a wavelength of 460 nm is not more than 50%, that of light having a wavelength of 540 nm is not less than 70%, and the ratio of the reflection factor of light having a wavelength of 540 nm to the reflection factor of light having a wavelength of 460 nm is not less than 1.3 and not more than 2.5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a light emitting device including a light emitting element such as a light emitting diode (LED) that emits blue light.

  LED lamps using light emitting diodes (LEDs) are rapidly expanding in various fields such as backlights for liquid crystal displays, mobile phones, information terminals, indoor / outdoor advertisements, and the like. In addition, LED lamps have long life and high reliability, and have features such as low power consumption, impact resistance, high-purity display colors, and lightness and thinness. Application is also being attempted. When such an LED lamp is applied to various uses, it is important to obtain white light.

  As a typical method for realizing white light emission with an LED lamp, (1) a method using three LED chips that emit light in blue, green and red colors, and (2) a blue light emitting LED chip and yellow light or orange light. There are three methods: a combination of yellow phosphors that emit light, and (3) a combination of ultraviolet light emitting LED chips and blue, green, and red three-color mixed phosphors. Among these, from the viewpoint of luminance characteristics, the method of combining the LED chip (2) that emits blue light and the yellow phosphor that emits yellow light or orange light has been widely put into practical use.

  As a structure of the LED lamp to which the above methods (2) and (3) are applied, a transparent resin mixed with a phosphor emitting a desired color is poured into a cup-shaped frame equipped with an LED chip, and this is solidified. A structure in which a resin layer containing a phosphor is formed is employed (see, for example, Patent Documents 1 to 3). In such an LED lamp, improvement of light extraction efficiency based on the electrode shape of an LED chip such as a flip chip, light distribution control by examining the chip shape, etc. are being advanced, and the amount of light to the front surface of the chip increases. There is a tendency.

  On the other hand, in addition to industrial applications that have been developed so far, lighting applications that are expected to develop rapidly are becoming increasingly multi-frame in anticipation of illuminance. As the number of frames increases, color variations between frames and color differences at each observation angle in individual frames (hereinafter referred to as “angle color differences”) have become major problems, and these are reduced. It is demanded.

The angle color difference in each frame is caused by the difference in the light distribution between the light emitted from the LED chip (for example, blue light) and the light emitted from the phosphor (for example, yellow light or orange light), and measures are taken. As factors, the shape of the concave portion inside the cup-shaped frame, the shape of the resin layer containing the phosphor, the particle size of the phosphor, the mixing ratio, and the like are considered.
JP 2001-148516 A Japanese Utility Model Publication No. 6-54081 JP-A-7-99345

  As a method for reducing the angular color difference, for example, it is conceivable to reduce the optical path difference as described above by reducing the diameter of the opening end of the concave portion of the cup-shaped frame and bringing it closer to the point light source. It is also conceivable to reduce the angular color difference as described above by reducing the depth of the recess.

  However, if the diameter of the opening end of the concave portion is reduced or the depth is reduced, the volume in the concave portion is reduced as a result. Therefore, it is difficult to sufficiently flow the transparent resin containing the phosphor into the concave portion. Become. For this reason, the amount of the phosphor in the recess is reduced, and particularly the amount of the red phosphor added together with the yellow phosphor is limited, so that it is difficult to obtain a color temperature as low as 5000 K or less, for example, a light bulb color. Become.

  The present invention has been made to solve the above-described problems, and has a relatively small concave portion with a small diameter or a shallow depth that is effective for reducing the angular color difference. An object of the present invention is to provide a light emitting device such as an LED lamp, which can reduce an angular color difference and can easily obtain a color temperature as low as 5000 K or less.

The light-emitting device according to claim 1, a base including a recess having a diameter of an opening end of 1.0 mm to 2.0 mm; a light-emitting element that emits blue light disposed in the recess; and covers the light-emitting element A resin layer containing at least a phosphor that is formed in the recess and is excited by blue light emitted from the light emitting element and emits at least yellow light, wherein the coating volume in the recess is 5 mm ³ or less. A body-containing resin layer; formed on at least a part of the inner surface of the recess, having a reflectance of light of a wavelength of 460 nm of 50% or less, a reflectance of light of a wavelength of 540 nm of 70% or more, and the light of a wavelength of 460 nm A reflection layer having a ratio of the reflectance of the light having a wavelength of 540 nm to the reflectance of 1.3 or more and 2.5 or less.

The light-emitting device according to claim 2, wherein the base includes a recess having a depth of 0.5 mm or more and 0.8 mm or less; a light-emitting element that emits blue light disposed in the recess; and the light-emitting element covers the light-emitting element. A resin layer containing at least a phosphor that is formed in a recess and is excited by blue light emitted from the light emitting element and emits at least yellow light, the coating volume in the recess being 5 mm ³ or less A resin layer; formed on at least a part of the inner surface of the concave portion; the reflectance of light having a wavelength of 460 nm is 50% or less; the reflectance of light having a wavelength of 540 nm is 70% or more; and the reflectance of light having a wavelength of 460 nm And a reflective layer having a reflectance ratio of light having a wavelength of 540 nm to 1.3 to 2.5.

  The light emitting device according to claim 3 is the light emitting device according to claim 1 or 2, wherein the reflective layer is made of gold.

  The light-emitting device according to claim 4 is the light-emitting device according to any one of claims 1 to 3, wherein an angle color difference (Δuv) at an observation angle of more than 0 ° and 70 ° or less is 0.012 or less. It is a feature.

  The light emitting device according to claim 5 is the light emitting device according to any one of claims 1 to 4, characterized in that the color temperature is 5000K or less.

  The definitions and technical meanings of terms in the present invention are as follows unless otherwise specified.

  The base has a concave portion opened to the outside, and is composed of, for example, a substrate having a wiring portion such as a circuit pattern or a lead terminal, and a frame provided on the substrate and having a concave portion opened to the outside. It is. A light emitting element is disposed and mounted in the recess. The base may be one in which a recess is formed directly on the substrate without using a frame.

  The light emitting element emits blue light, and for example, a blue light emitting type LED chip is exemplified. A phosphor is a phosphor that emits at least yellow light when excited by blue light emitted from a light emitting element, and a red phosphor that emits red light or a green phosphor that emits green light as needed. Is used.

The phosphor-containing resin layer is a layer in which such a phosphor is mixed and dispersed in a transparent resin, and is formed in the recess of the base so as to cover the light emitting element. The coating volume is the volume of the phosphor-containing resin layer actually applied to the recess, and of course the volume of the phosphor-containing resin layer applied in the recess, for example, the phosphor-containing resin layer from the opening end of the recess When a part of the projection protrudes to form a convex portion, the volume of the convex portion is also included.

  The reflective layer has a reflectance of light of wavelength 460 nm of 50% or less, a reflectance of light of wavelength 540 nm of 70% or more, and a ratio of the reflectance of light of wavelength 540 nm to the reflectance of light of wavelength 460 nm (wavelength 540 nm). (Reflectance of light / reflectivity of light having a wavelength of 460 nm) has a reflection characteristic of 1.3 or more and 2.5 or less. Examples of such a material include those made of gold. .

  The reflective layer is formed on the inner surface of the recess, that is, at least a part of the inner side surface and the outer side surface, preferably formed on at least the inner side surface of the recess, and more preferably on the entire inner surface composed of the inner side surface and the outer side surface. It is formed.

  The angle color difference (Δuv) is a difference in chromaticity for each observation angle calculated from the u value and the v value in the CIE 1976 UCS system chromaticity diagram. If the difference in chromaticity when the observation angle is greater than 0 degrees and less than 70 degrees is 0.012 or less, it is not recognized as a color variation by human eyes, but if it exceeds that, it is recognized as a color variation. The angular color difference (Δuv) at the observation angle X degree can be obtained by the following equation (1).

Δuv = {(u _X −u ₀ ) ² + (v _X −v ₀ ) ² } ^1/2 (1)
Here, u _X and v _X are u value and v value (CIE 1976 UCS system chromaticity diagram) when an emission spectrum with a wavelength of 380 to 780 nm is measured at an observation angle of X degrees, and u ₀ and v ₀ are They are u value and v value when an emission spectrum with a wavelength of 380 to 780 nm is measured at an observation angle of 0 degree. Note that the emission spectra at the observation angles of X degrees and 0 degrees are measured by an instantaneous spectrophotometer at a location 300 mm away from the center of the upper surface of the phosphor-containing resin layer.

  According to the first and second aspects of the invention, the phosphor-containing resin layer having a specific coating volume is formed in the concave portion having an opening end or depth having a specific size, and at least one of the inner surfaces of the concave portion is formed. By forming a reflective layer having specific reflection characteristics in the part, the angle color difference is reduced, a low color temperature like a light bulb color can be easily obtained, and a light emitting device with excellent luminous efficiency is obtained. Can do.

  According to the third aspect of the invention, since the reflective layer is made of gold, it is possible to prevent or reduce deterioration over time due to oxidation or sulfuration of the reflective layer.

  According to the fourth aspect of the present invention, it is possible to realize an angular color difference that has little influence on a person as a lighting application.

  According to the invention described in claim 5, a color temperature as low as 5000K or less can be easily obtained.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the part which is the same or it corresponds in several drawing. FIG. 1 is a cross-sectional view showing a configuration of an LED lamp 1 which is an example of a light-emitting device of the present invention. FIG. 2 is a diagram showing a plurality of LED lamps 1 shown in FIG. FIG. 3 is a cross-sectional view taken along the line AA ′ of FIG. 2, and FIG. 3 is a plan view showing an LED module 20 which is another example of the light emitting device of the present invention arranged. Note that the LED module 20 may have a structure in which, for example, a plurality of LED lamps are arranged in a row and integrally coupled.

  The LED lamp 1 shown in FIG. 1 has a base 3 having a recess 2 on the surface. The base 3 has, for example, a structure in which an electrical insulating layer 5, a circuit pattern 6, and a frame 7 are sequentially laminated on a substrate 4, and the recess 2 is formed in the frame 7. The recess 2 has an open end 2a, and a reflective layer 8 is formed on the inner side surface 2b and the inner bottom surface 2c, which are the inner surfaces thereof.

  The LED chip 10 is mounted on one electrode (cathode or anode) in the circuit pattern 6 via a reflective layer 8, and its bottom electrode is electrically connected to the one electrode via the conductive reflective layer 8. Has been. The upper surface electrode of the LED chip 10 is connected to the reflective layer 8 formed on the other electrode of the circuit pattern 6 through a bonding wire 11 such as a gold wire. A phosphor-containing resin layer 12 is formed inside the recess 2 so as to cover the LED chip 10.

  The substrate 4 is made of, for example, a flat plate made of aluminum (Al), nickel (Ni), glass epoxy or the like having heat dissipation and rigidity, and is made of, for example, an alloy of Cu and Ni, Au, or the like via an electrical insulating layer 5 thereon. The cathode side and anode side circuit patterns 6 are respectively formed. Between the circuit pattern 6 on the cathode side and the anode side, an electrical insulator portion 9 such as resin is interposed. The frame 7 having the recesses 2 is made of a synthetic resin such as PBT (polybutylene terephthalate), PPA (polyphthalamide), or PC (polycarbonate).

  In the recess 2, the diameter D of the opening end 2 a is 1.0 mm or more and 2.0 mm or less, or the depth d of the recess 2 (distance in the direction perpendicular to the bottom surface 2 b from the opening end 2 a to the bottom surface 2 b). 0.5 mm or more and 0.8 mm or less. Thus, in the present invention, by setting the size of the concave portion 2 to be smaller than that of a general one, the optical path difference between the light emitted from the LED chip 10 and the light emitted from the phosphor is reduced, and the angle color difference is reduced. Can be reduced.

  As described above, the diameter D and the depth d of the open end 2a do not need to be in the above range at the same time, and any one of them may be in the above range. That is, when the diameter D of the opening end 2a of the recess 2 exceeds 2.0 mm and the depth d exceeds 0.8 mm, the size of the recess 2 increases, and the angular color difference cannot be sufficiently reduced. .

  From the viewpoint of reducing the angle color difference, there is no particular problem as long as the diameter D and the depth d of the opening end 2a are within the above ranges, but if the diameter D of the opening end 2a is too small such as less than 1.0 mm, the fluorescence When the body-containing resin layer 12 is formed, the phosphor-containing resin may overflow from the recess 2. For those having such a diameter D, since it is difficult to adjust the coating volume of the phosphor-containing resin in the first place, for example, a plurality of LED lamps 1 arranged on a plane like the LED module 20 is used. The color variation for each LED lamp 1 increases.

  On the other hand, when the depth d is too shallow such as less than 0.5 mm, the bonding wire 11 connected to the upper surface electrode of the LED chip 10 may be exposed from the surface of the phosphor-containing resin layer 12. For this reason, the diameter D of the opening end 2a of the recessed part 2 is 1.0 mm or more, and the depth d is 0.5 mm or more.

Containing a phosphor having a coating volume of 5 mm ³ or less with respect to the diameter D or depth d of the other open end 2a when either the diameter D or the depth d of the open end 2a is adjusted as described above For example, when the diameter D of the open end 2a is set to 1.0 mm or more and 2.0 mm or less as described above, the depth d is 0.8 mm or more and 1 as long as the resin layer 12 can be formed. .2 mm or less, and when the depth d is 0.5 mm or more and 0.8 mm or less as described above, the diameter D of the open end 2a is 2.0 mm or more and 3.5 mm or less. Is preferred.

  Table 1 below shows the relationship between the diameter D of the opening end 2a of the recess 2 and the angle color difference (Δuv), and Table 2 shows the relationship between the depth d of the recess 2 and the angle color difference (Δuv). Is shown. Sample No. Nos. 1 to 8 are obtained by forming only the Ni plating layer on the inner side surface 2b and the inner bottom surface 2c of the recess 2. 1-4 have a constant depth d of 1.0 mm, and sample Nos. 5-7 make the diameter D of the opening end 2a constant at 3.0 mm.

  As can be seen from Table 1, the sample No. 2 in which the diameter D of the open end 2a is 1.0 mm or more and 2.0 mm or less. 2 to 3, in any observation angle, the angle color difference (Δuv) is 0.012 or less which is not recognized as a color variation by human eyes, whereas the diameter D of the open end 2a is 2. Sample No. exceeding 0 mm 4 shows that the angle color difference (Δuv) exceeds 0.012 when the observation angle is 70 °. Sample No. Although there is no problem with the angular color difference (Δuv) for No. 1, the diameter D of the opening end 2a of the recess 2 is too small, and therefore the phosphor-containing resin overflows from the recess 2 when the phosphor-containing resin layer 12 is formed. There is a problem such as getting out.

  Further, as apparent from Table 2, the sample No. having a depth d of 0.5 mm or more and 0.8 mm or less. For 5 and 6, the angle color difference (Δuv) is 0.012 or less which is not recognized as a color variation by human eyes, but the depth d exceeds 0.8 mm in any observation angle. Sample No. 7 shows that the angle color difference (Δuv) exceeds 0.012 when the observation angle is 70 °.

  The reflection layer 8 is formed on the inner side surface 2b and the inner bottom surface 2c, which are the inner surfaces of the recess 2, as described above, and the reflection layer 8 formed on the inner bottom surface 2c is formed on the circuit patterns 6 on the cathode side and the anode side. Correspondingly, it is insulated from the cathode side and the anode side by the electric insulator 9.

  The reflective layer 8 has a reflectance of light having a wavelength of 460 nm corresponding to blue light from the LED chip 10 of 50% or less, and a reflectance of light having a wavelength of 540 nm corresponding to yellow light emission from the phosphor is 70% or more. Further, a reflection characteristic in which the ratio of the reflectance of the light of wavelength 540 nm to the reflectance of the light of wavelength 460 nm (the reflectance of the light of wavelength 540 nm / the reflectance of the light of wavelength 460 nm) is 1.3 or more and 2.5 or less. Have.

  When the reflectance of light having a wavelength of 460 nm exceeds 50%, it becomes difficult to set the color temperature to 5000 K or less, for example, a light bulb color. That is, when the reflectance of light having a wavelength of 460 nm exceeds 50%, the reflection of blue light from the LED chip 10 increases, and in order to obtain a color temperature of 5000 K or less, for example, a light bulb color, the phosphor-containing resin layer 12. A large amount of red phosphor must be contained therein.

  However, when the size of the concave portion 2 is set to be smaller than that of a general one as in the present invention, the amount of the phosphor in the concave portion is reduced, and particularly the amount of the red phosphor added together with the yellow phosphor. Therefore, it becomes difficult to obtain a color temperature of 5000 K or less, such as a light bulb color.

  Further, when the reflectance of light having a wavelength of 540 nm is less than 70%, the reflection of yellow light or orange light emitted from the phosphor and further red light is reduced, and a color temperature of 5000 K or less, for example, a light bulb color, etc. It becomes difficult to obtain.

  Further, even when the reflectance of light having a wavelength of 460 nm or light having a wavelength of 540 nm is within the above-described range, the ratio of these reflectances (reflectance of light having a wavelength of 540 nm / light having a wavelength of 460 nm) Is less than 1.3, the yellow or orange light emitted from the phosphor and the red light are relatively less reflected than the blue light reflected from the LED chip 10. Therefore, it becomes difficult to obtain a color temperature of 5000 K or less, such as a light bulb color. On the other hand, if the reflectance ratio exceeds 2.5, the yellow light, orange light, or red light emitted from the phosphor is excessively reflected from the blue light reflected from the LED chip 10, so that The effect is reduced.

  Examples of the reflection layer 8 having the above-described reflection characteristics include those made of Au (gold), and those formed by a plating method or the like. The thickness of the reflective layer 8 is preferably 0.2 μm or more and 0.4 μm or less because the total reflectance at a required wavelength is high.

  FIG. 4 is a graph showing the visible light reflectance representing the reflection characteristics of the Au (gold) plating layer compared with the visible light reflectance representing the reflection characteristics of the Ni (nickel) plating layer. As shown by the curve A in the figure, the visible light reflectance of the Ni plating layer is about 50 in the short wavelength region of 400 to 480 nm including the wavelength of blue light (for example, 460 nm) of the blue light emitting LED chip 10. %, The reflectance in a long wavelength region of 550 nm or more is about 65 to 70%, which is not necessarily high.

  On the other hand, as shown by the B curve, the visible light reflectance of the Au plating layer is approximately the reflectance in the short wavelength region of 400 to 480 nm including the wavelength of blue light (for example, 460 nm) of the blue light emitting LED chip 10. About 40%, which is lower than the reflectance of the Ni plating layer, but the reflectance in the long wavelength region of 550 nm or more is about 80 to 100%, which is about 20 to 30% higher than the reflectance of the Ni plating layer. .

  As shown in the figure, the Au plating layer has a light reflectance of about 460 nm and about 50% or less, a light reflectance of about 540 nm and about 80% and 70% or more, and Since the latter reflectivity is about twice that of the former reflectivity, the requirement as a reflective layer in the present invention is provided.

  The reflective layer 8 is preferably formed integrally with the inner side surface 2b and the inner bottom surface 2c of the recess 2, but may be formed separately. The reflective layer 8 is preferably formed on the inner side surface 2b and the inner bottom surface 2c of the recess 2, that is, almost all of the inner surface of the recess 2, but one surface selected from the inner side surface 2b and the inner bottom surface 2c. It may be formed only on. When formed on both the inner side surface 2b and the inner bottom surface 2c, the reflectance of light is further improved, and accordingly, a color temperature of 5000K or less, such as a light bulb color, is easily obtained.

  Furthermore, a base layer (not shown) may be formed below the reflective layer 8, that is, between the reflective layer 8 and the recess 2. Examples of the underlayer include those made of Ni, for example, those formed by a plating method or the like. In the case where the Ni layer is formed as the underlayer, there is an advantage that the coating property when the reflective layer 8 made of Au is applied is improved.

  The LED chip 10 is made of, for example, a gallium nitride (GaN) -based semiconductor, and emits blue light having a dominant wavelength of 420 to 480 nm (for example, 460 nm) by applied electric energy. The length of one side of the LED chip 10 is 200 nm or more and 1 mm or less because the diameter D or the depth d of the opening end 2a is an appropriate size for placement in the recess 2 within the above-described range. It is preferable that

  Note that a flip-chip connection structure can also be applied as the electrode connection structure of the LED chip 10. According to these electrode connection structures, the light extraction efficiency to the front surface of the LED chip 10 is improved.

  In the recess 2, a phosphor-containing resin in which a yellow phosphor is mixed and dispersed in a transparent resin is applied, and the LED chip 10 is a phosphor-containing resin layer that is a cured product of such a phosphor-containing resin. 12 is covered. The phosphor-containing resin layer 12 is formed, for example, by adding and mixing a yellow phosphor to a liquid transparent resin such as a silicone resin or an epoxy resin, and dropping and applying the mixture into the recess 2 with a dispenser, followed by curing. Is done.

Examples of yellow phosphors include YAG phosphors such as RE ₃ (Al, Ga) ₅ O ₁₂ : Ce phosphor (RE represents at least one selected from Y, Gd, and La), AE ₂ SiO, and the like. ₄ : Silicate phosphor such as Eu phosphor (AE is an alkaline earth element such as Sr, Ba, Ca), n-UVLED BGR, nitride phosphor, oxynitride phosphor, sialon phosphor, etc. Is used.

Further, in order to change the color temperature to 5000 K or less, for example, a light bulb color, or to improve the color rendering, etc., the red color is excited by the blue light emitted from the LED chip 10 together with such a yellow phosphor. You may contain the red fluorescent substance which light-emits light. As the red phosphor, an oxysulfide phosphor such as a La ₂ O ₂ S: Eu phosphor is used, but it is not particularly limited.

Such a phosphor-containing resin layer 12 has an application volume in the recess 2 of 5 mm ³ or less. As described above, when the recess 2 is relatively small such that the diameter D of the open end 2a is 1.0 mm or more and 2.0 mm or less or the depth d is 0.5 mm or more and 0.8 mm or less, the coating volume exceeds 5 mm ³ . When the phosphor-containing resin layer 12 is to be formed, the ratio of the thickness of the phosphor-containing resin layer 12 to the depth of the recess 2 (including the portion formed in a convex shape beyond the horizontal plane of the opening end 2a) When the phosphor-containing resin is applied or cured, the phosphor-containing resin whose viscosity has been reduced by heating may overflow from the recess 2.

Since the phosphor-containing resin layer 12 is usually formed from the bottom surface 2c of the recess 2 to the horizontal surface of the opening end 2a, the coating volume at that time may be in the range as described above. The resin layer 12 may be formed in a convex shape exceeding the horizontal plane of the opening end 2a. In such a case, the coating volume including the convex portion exceeding the horizontal plane is within the range as described above. That's fine. In addition, the lower limit value of the coating volume in the recess 2 is not necessarily limited, but if the coating volume is too small, the amount of phosphor in the recess is reduced, and a color temperature of 5000 K or less, such as a light bulb color, is obtained. Since it becomes difficult, it is preferable to set it as 1.5 mm < ³ > or more, and it is more preferable to set it as 2 mm < ³ > or more.

  In the LED lamp 1 or the LED module 20 in which the LED lamps 1 are integrally formed, electric energy applied to each LED lamp 1 is converted into blue light by the LED chip 10, and yellow fluorescent light is converted by the blue light. The body or red phosphor is excited to emit yellow light or orange light or red light, and the blue light emitted from the LED chip 10 is mixed with yellow light, orange light or red light emitted from the yellow phosphor. White light is obtained.

  In the present invention, the diameter D of the opening end 2a of the recess 2 is set to 2.0 mm or less or the depth d is set to 0.8 mm or less, and the size thereof is set to be smaller than that of a general one. The optical path difference between the light emitted from the phosphor and the light emitted from the phosphor can be reduced, and the angular color difference can be reduced.

  And about what has such a small recessed part 2, since the volume in the recessed part 2 generally becomes small, the quantity of fluorescent substance also decreases, and especially the quantity of the red fluorescent substance contained in addition to a yellowish fluorescent substance Therefore, it becomes difficult to obtain a color temperature of 5000 K or less, such as a light bulb color.

  However, in the present invention, the reflectance of light having a wavelength of 460 nm corresponding to the blue light from the LED chip 10 is low on at least a part of the inner side surface 2b and the inner bottom surface 2c, which are the inner surfaces of the concave portion 2, and the yellow color from the phosphor. By providing the reflective layer 8 having a high reflectance of light having a wavelength of 540 nm corresponding to light emission, yellow light or orange light and further red light can be increased compared to blue light, and the content of the red phosphor Even when there is little, it becomes easy to obtain color temperature of 5000K or less, for example, a light bulb color. Moreover, it can also be made excellent in luminous efficiency by reducing content of a red fluorescent substance.

  Therefore, according to the present invention, the angular color difference can be reduced by making the concave portion 2 relatively small. Further, it has been difficult to obtain a color temperature of 5000 K or less, such as a light bulb color. Can be easily obtained by providing the reflective layer 8 having specific reflection characteristics, and a light emitting device having excellent luminous efficiency can be obtained.

  As described above, the light emitting device of the present invention has been described by taking the LED lamp 1 and the LED module 20 formed integrally with the LED lamp 1 as an example. However, the light emitting device of the present invention is not necessarily such. It is not limited, and the structure, material, and the like can be appropriately changed as necessary without departing from the spirit of the present invention.

  Hereinafter, the present invention will be described in detail with reference to examples.

Example 1
A base body 3 having a recess 2 having a diameter D of 1.5 mm at the open end 2a and a depth d of 1.0 mm is prepared, and the inner surface (inner side surface 2b and inner bottom surface 2c) of the recess 2 is plated with Au by plating. A layer (reflection layer 8) was formed. Further, an LED chip 10 that emits blue light made of a gallium nitride (GaN) -based semiconductor is mounted on the inner bottom surface 2c of the recess 2, and a phosphor-containing resin containing a yellow phosphor and a red phosphor is applied in a volume of 1. The phosphor-containing resin layer 12 was formed by coating so as to be 5 mm ^3, and the LED lamp 1 having a structure as shown in FIG. 1 was manufactured.

  The phosphor-containing resin is obtained by dispersing a YAG phosphor having a dominant wavelength of 540 nm as a yellow phosphor and a red-emitting phosphor having a dominant wavelength of 650 nm as a red phosphor in a silicone resin. The content of the yellow phosphor in the entire resin contained is 10% by weight, and the content of the red phosphor is 3% by weight.

(Comparative Example 1)
An LED lamp was manufactured in the same manner as in Example 1 except that a Ni plating layer was formed instead of the Au plating layer.

(Example 2)
A base 3 having a recess 2 with a diameter D of the open end 2a of 3.0 mm and a depth d of 0.7 mm is prepared, and the inner surface (the inner side surface 2b and the inner bottom surface 2c) of the recess 2 is plated with Au by plating. Except that the phosphor (resin layer 8) is formed, and the phosphor-containing resin layer 12 is formed by applying a phosphor-containing resin containing a yellow phosphor and a red phosphor so as to have a coating volume of 4.2 mm ^3. Produced the LED lamp 1 as shown in FIG. Further, the phosphor-containing resin used for forming the phosphor-containing resin layer 12 was also of the same composition as the phosphor-containing resin used in Example 1.

(Comparative Example 2)
An LED lamp was manufactured in the same manner as in Example 2 except that a Ni plating layer was formed instead of the Au plating layer.

  Next, for the LED lamps 1 of Examples 1 and 2 and Comparative Examples 1 and 2, the angle color difference (Δuv) when the observation angles were 50 ° and 70 ° was calculated, and the color temperature was measured. The results are shown in Table 3.

  As is apparent from Table 3, the LED lamps 1 of Examples 1 and 2 in which the diameter D or depth d of the open end 2a of the recess 2 is within a predetermined range and an Au plating layer is formed on the inner surface of the recess 2 As compared with the LED lamps 1 of Comparative Example 1 and Comparative Example 2 in which the Ni plating layer is formed on the inner surface of the recess 2, the angle color difference (Δuv) can be made comparable or less and the color temperature It can be seen that a color temperature of about 3000K can be easily obtained.

Sectional drawing which shows the LED lamp which is an example of the light-emitting device of this invention. The top view which shows an example of the light-emitting device of this invention which has arranged several LED lamps shown in FIG. 1 in the matrix form, and was set as the LED module. AA 'line sectional drawing of the LED module shown in FIG. The graph which compared and showed the visible light reflectance of Au (gold) plating layer, and the visible light reflectance of Ni (nickel) plating layer.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... LED lamp, 2 ... Recessed part (2a ... Open end, 2b ... Inner side surface, 2c ... Inner bottom surface), 3 ... Base | substrate, 4 ... Substrate, 5 ... Electrical insulation layer, 6 ... Circuit pattern, 7 ... Frame, 8 ... Reflective layer, 9 ... electric insulator, 10 ... LED chip, 11 ... bonding wire, 12 ... phosphor-containing resin layer, 20 ... LED module

Claims (5)

A substrate provided with a recess having an opening end diameter of 1.0 mm or more and 2.0 mm or less;
A light emitting element emitting blue light disposed in the recess;
A resin layer that is formed in the recess so as to cover the light emitting element and contains at least a phosphor that emits at least yellow light when excited by the blue light emitted from the light emitting element, and the coating volume in the recess is A phosphor-containing resin layer that is 5 mm ³ or less;
Formed on at least a part of the inner surface of the recess, the reflectance of light with a wavelength of 460 nm is 50% or less, the reflectance of light with a wavelength of 540 nm is 70% or more, and the wavelength of 540 nm with respect to the reflectance of light with a wavelength of 460 nm A reflective layer having a light reflectance ratio of 1.3 to 2.5;
A light-emitting device comprising: A substrate provided with a recess having a depth of 0.5 mm or more and 0.8 mm or less;
A light emitting element emitting blue light disposed in the recess;
A resin layer that is formed in the recess so as to cover the light emitting element and contains at least a phosphor that emits at least yellow light when excited by the blue light emitted from the light emitting element, and the coating volume in the recess is A phosphor-containing resin layer that is 5 mm ³ or less;
Formed on at least a part of the inner surface of the recess, the reflectance of light with a wavelength of 460 nm is 50% or less, the reflectance of light with a wavelength of 540 nm is 70% or more, and the wavelength of 540 nm with respect to the reflectance of light with a wavelength of 460 nm A reflective layer having a light reflectance ratio of 1.3 to 2.5;
A light-emitting device comprising:   The light emitting device according to claim 1, wherein the reflective layer is made of gold.   4. The light emitting device according to claim 1, wherein an angle color difference (Δuv) when the observation angle is greater than 0 degree and equal to or less than 70 degrees is 0.012 or less. 5.   The light emitting device according to claim 1, wherein the color temperature is 5000 K or less.

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