JP2003142737A - Light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain uniform light emission, reduced in the variety of color or white light for example, with a high output. SOLUTION: A reflector unit (14) is formed on a base surface (10) employing a transparent resin material while surrounding a semiconductor light emitting device (11), and at least the lower part in the direction of the height of inner surface of the reflector unit is provided with a curved configuration, extending obliquely outward and upward in a height from the base surface or the vicinity of the same and whose substantially arcuately recessed section is continuous across the substantially whole circumference of the lower part while a fluorescent substance, emitting light while being excited by the light from the semiconductor light emitting device, is dispersed on the reflector unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device, and more particularly to a device capable of obtaining uniform light emission with little color unevenness, for example, white light at high output.

[0002]

2. Description of the Related Art Semiconductor light-emitting devices with high brightness and low power consumption, such as light-emitting diodes (LEDs), tend to be adopted as light sources for portable electronic devices, guide lights, indicator lights and the like. When constructing a light emitting device using such a semiconductor light emitting element, it is necessary to convert the light emission of the semiconductor light emitting element as a point light source into surface emission.

Conventionally, as a method of realizing surface emission, a method of mounting a film containing a diffusing agent on the front surface of a semiconductor light emitting element chip for surface emission, and mounting a lens on the front surface of the semiconductor light emitting element chip to direct light. There have been adopted a method of making surface emission by controlling the property, a method of mounting a semiconductor light emitting element chip at a high density to form a pseudo surface emission, and the like.

However, the method of using the film containing the diffusing agent lowers the light transmittance due to the diffusing agent, and the method of using the lens or the method of mounting at a high density leads to high cost.

On the other hand, a method has been proposed in which a reflector is formed around the semiconductor light emitting element, and a part of light emitted from the semiconductor light emitting element is reflected forward by the reflector to emit light in a plane.

Recently, white light is often required. When a white light emitting device is constructed, a semiconductor light emitting element emits blue light, while a YAG (yttrium aluminum garnet) based light is contained in a sealing resin. A method is mainly adopted in which a fluorescent substance is dispersed, a part of light emitted from a semiconductor light emitting element is absorbed and wavelength is converted to emit yellow light, and blue light and yellow light are mixed to obtain white light. ing.

Although a uniform white light with less color unevenness can be obtained by the method of mixing the YAG type fluorescent substance in the sealing resin, the fluorescent substance has a poor light transmittance in the sealing resin and secures a light output. It's hard to do.

Therefore, a number of methods of coating the reflector with a YAG-based fluorescent substance have been proposed (Japanese Patent Laid-Open Nos. 10-112557 and 11-27457).
No. 2, JP-A-2000-81847, etc.).

[0009]

However, in the structure described in the above-mentioned conventional publication, the light emission from the side end surface of the semiconductor light emitting element has not been sufficiently utilized.

Further, in the structure described in the above publication, light is not sufficiently scattered inside the cavity in which the semiconductor light emitting element is mounted, and the semiconductor light emitting element emits blue light and the reflector portion emits yellow light, resulting in uneven color. There was a problem that it became a certain white light.

An object of the present invention is to provide a light emitting device capable of obtaining uniform white light with little color unevenness at high output.

[0012]

A light emitting device according to the present invention comprises a semiconductor light emitting element which emits at least a part of light emission from a side end surface thereof, and a fluorescent member which is arranged apart from the semiconductor light emitting element. The member is capable of absorbing a part of the light emitted from the semiconductor light emitting element, converting the light into another light and emitting the light, and at least one selected from the group consisting of Y, Lu, Sc, La, Gd and Sm. Two elements and Al, Ga and In
Pr, Sm, Cu, Ag, Au, F together with at least Ce and at least one element selected from the group
At least one element selected from the group consisting of e, Cr, Nd, Dy, Ni, Ti, Tb, and Eu is included as at least a constituent yttrium aluminum garnet-based fluorescent material, and the fluorescent member includes a semiconductor light emitting device It has a first portion located at one distance and a second portion located farther than the first distance, and the first portion has a higher absorption rate of light emitted from the semiconductor light emitting element than the second portion. Characterize.

By using the above fluorescent substance, it is possible to obtain a luminescent color excellent in color rendering.

Further, regarding each part of the fluorescent member, the absorption rate of the light emitted from the semiconductor light emitting element is set to be higher as the distance from the semiconductor light emitting element is closer, so that the light emission from the side end surface of the semiconductor light emitting element is increased. Can be fully utilized. Thereby, in the entire fluorescent member, the ratio of the amount of light wavelength-converted by the fluorescent member to the amount of light emitted from the light emitting element can be made substantially equal,
A uniform luminescent color with excellent color rendering and less color unevenness can be obtained.

Further, the light emitting device according to the present invention comprises a semiconductor light emitting element which emits at least a part of light emission from the side end surface, and a fluorescent member which is arranged apart from the semiconductor light emitting element.
The fluorescent member is capable of absorbing a part of the light emitted from the semiconductor light emitting element and converting it into other light to emit light, and the fluorescent member includes a first portion located at a first distance from the semiconductor light emitting element, A second portion located farther than the first distance, wherein the first portion has a higher absorption rate of light emitted from the semiconductor light emitting element than the second portion.

By setting each part of the fluorescent member such that the absorption rate of the light emitted from the semiconductor light emitting element becomes higher as the distance from the semiconductor light emitting element becomes shorter, the light emission from the lateral end surface of the semiconductor light emitting element is sufficiently increased. In the entire fluorescent member, the ratio of the amount of light wavelength-converted by the fluorescent member to the amount of light emitted from the light emitting element can be made substantially uniform. As a result, a uniform luminescent color having excellent color rendering properties and less color unevenness can be obtained.

In the present invention, the fluorescent member is formed of a translucent member in which a fluorescent substance is dispersed, and the absorptance is adjusted continuously or stepwise according to the absolute amount of the fluorescent substance. preferable.

By changing the absolute amount of the fluorescent substance continuously or stepwise for each part of the fluorescent member, the absorption rate can also be continuously or stepwise adjusted.

In the present invention, in the fluorescent member, the first
It is preferable that the portion has a higher density of the fluorescent substance than the second portion.

By changing the density of the fluorescent substance continuously or stepwise for each part of the fluorescent member,
The absorption rate can also be adjusted continuously or in steps.

In the present invention, it is preferable that the fluorescent member is formed by laminating a plurality of types of fluorescent substances, and the absorptance is adjusted according to the light conversion efficiency of each fluorescent substance.

The absorptivity can also be adjusted continuously or stepwise by constructing the fluorescent member with a laminated structure composed of plural kinds of fluorescent substances and changing the light conversion efficiency of each fluorescent layer continuously or stepwise. become.

In the present invention, it is preferable that the fluorescent member contains at least a fluorescent substance and a light diffusing agent as constituent members, and the absorptance is adjusted according to the density of the light diffusing agent.

By incorporating a light diffusing agent into the fluorescent member and changing the density of the light diffusing agent continuously or stepwise, the luminescence absorption rate can also be adjusted continuously or stepwise.

In the present invention, in the fluorescent member, the first
It is preferable that the portion has a higher density of the light diffusing agent than the second portion.

By setting each part of the fluorescent member such that the density of the light diffusing agent becomes higher as the distance from the semiconductor light emitting element becomes shorter, the light emitted in high density from the side end surface of the semiconductor light emitting element is reflected. By scattering, the light conversion efficiency of the fluorescent member can be increased. Thereby, in the entire fluorescent member, the ratio of the amount of light wavelength-converted by the fluorescent member to the amount of light emitted from the light emitting element can be made substantially uniform, and a uniform emission color with little color unevenness can be obtained.

In the present invention, it is preferable that the fluorescent member is disposed on the lateral end surface of the semiconductor light emitting element and includes a flat shape or a curved shape capable of reflecting the light emitted from the semiconductor light emitting element.

As a result, the light emitted from the lateral end surface of the semiconductor light emitting element reaches the fluorescent substance and is effectively utilized for the emission of the fluorescent substance. In addition, since the fluorescent member includes a flat shape or a curved shape capable of reflecting the light emitted from the semiconductor light emitting element, the light emission from the semiconductor light emitting element and the light emission of the fluorescent substance are efficiently mixed, and the color unevenness is small. A uniform emission color can be obtained.

In the present invention, it is preferable to generate mixed color light of visible light from the semiconductor light emitting element and visible light from the fluorescent substance.

As a result, the light utilization efficiency is improved by the color mixture of the light emitted from the semiconductor light emitting element and the light emitted from the fluorescent material.

In the present invention, it is preferable that the mixed color light is white light, which allows it to be used as a backlight light source for various devices such as lighting equipment and signal lights.

A light emitting device according to the present invention includes an electrode provided on a base surface, a semiconductor light emitting element which is mounted on the base surface with a gap from the electrode and emits a part of light emission from a side end surface, and a semiconductor. A connection member for electrically connecting the light emitting element and the electrode, and a transparent resin material in which a fluorescent material that is excited by the light emitted from the semiconductor light emitting element and emits light are dispersed, are arranged so as to surround the semiconductor light emitting element. Equipped with a fluorescent member,
The fluorescent member is characterized by including a curved surface shape that reflects light emitted laterally from the semiconductor light emitting element in a direction away from the base surface.

One of the features of the present invention is that at least the lower portion of the fluorescent member in the height direction is formed into a curved surface of a concave arc shape extending obliquely outward and upward from the height of the base surface or the vicinity thereof, and the semiconductor light emitting element The curved surface shape that reflects the light radiated from the side away from the base surface is included, and the fluorescent material is dispersed with a fluorescent substance that is excited by the light emitted from the semiconductor light emitting element to emit light. It is in.

As a result, not only the light emitted obliquely forward from the semiconductor light emitting element, but most of the light emitted from the side end face reaches the fluorescent substance of the fluorescent member and is effectively utilized for the emission of the fluorescent substance. To be done. Therefore, as compared with the conventional structure in which the fluorescent substance is dispersed in the sealing resin, the light transmittance is high and a high light output can be secured.

Further, since at least the inner surface of the lower portion of the fluorescent member is formed into a curved surface having an arcuate concave shape, part of the light emitted from the semiconductor light emitting element and most of the light emitted from the end surface are more fluorescent than the flat reflector structure. The light is easily scattered by the member, the light emitted from the semiconductor light emitting element and the light emitted from the fluorescent substance are efficiently mixed, and a uniform emission color with less color unevenness can be obtained.

The fluorescent member may have an arc concave curved surface shape on at least the lower portion in the height direction. However, if the fluorescent member is formed in the arc concave curved surface shape in the entire height direction, the fluorescent member can be removed from the semiconductor light emitting element. A part of the light emission and most of the edge light emission can be used more efficiently, and the light output can be greatly improved.

Further, since the inner edge of the lower end of the fluorescent member is set to the height of the base surface or the vicinity thereof, most of the edge emission of the semiconductor light emitting element can reach the curved surface of the fluorescent member. It is preferable to provide a space between the inner edge of the lower end and the side end surface of the semiconductor light emitting element, whereby all the light emitted from the end surface of the semiconductor light emitting element reaches the curved surface of the fluorescent member, and the light output can be more surely improved.

In the present invention, the inner surface of the fluorescent member is preferably formed so as to substantially form a part of a paraboloid of revolution, an ellipsoid of revolution or a hyperboloid of revolution.

With such a structure, the light emitted from the semiconductor light emitting element can be efficiently collected, the light emission from the semiconductor light emitting element and the light emission of the fluorescent substance are efficiently mixed, and the light utilization efficiency is further improved. .

Further, the light emitting device according to the present invention includes an electrode provided on the base surface, a semiconductor light emitting element which is mounted on the base surface with a gap from the electrode, and emits a part of light emission from the side end surface. A connection member for electrically connecting the semiconductor light emitting element and the electrode, and a transparent resin material in which a fluorescent material that is excited by the light emitted from the semiconductor light emitting element and emits light are dispersed, are arranged so as to surround the semiconductor light emitting element. The fluorescent substance density in the fluorescent member is continuously or stepwise changed according to the height from the base surface.

Another feature of the present invention is that a fluorescent member arranged so as to surround the semiconductor light emitting element is made of a transparent resin material, and the fluorescent member is excited by the light emitted from the conductor light emitting element to emit fluorescent light. The substance is dispersed so that the density of the fluorescent substance changes continuously or stepwise depending on the height from the base surface.

As a result, not only the light emitted obliquely forward from the semiconductor light emitting element, but most of the light emitted from the side end face reaches the fluorescent substance of the fluorescent member and is effectively utilized for the emission of the fluorescent substance. To be done. Therefore, as compared with the conventional structure in which the fluorescent material is dispersed in the sealing resin, the light transmittance is higher and a high light output can be secured.

In the present invention, the fluorescent substance density in the fluorescent member preferably increases as the height from the base surface decreases.

By dispersing the fluorescent substance in the fluorescent member so that the density on the base surface side is higher than that on the surface side, the semiconductor light emission is achieved as compared with the conventional structure in which the fluorescent material is applied. Part of the light emitted from the device and most of the light emitted from the end face are likely to be scattered, the light emitted from the semiconductor light emitting device and the light emitted from the fluorescent substance are efficiently mixed, and a uniform emission color with less color unevenness can be obtained. .

The density of the fluorescent substance on the base surface side in the height direction may be made higher than that on the surface side. However, when the fluorescent material is gradually reduced from the base surface side to the surface side, the semiconductor light emitting element is obtained. It is possible to more efficiently use a part of the light emitted from the light emitting device and most of the light emitted from the end face, and it is possible to significantly increase the light output.

In the present invention, the transparent resin material of the fluorescent member is preferably epoxy resin, silicone resin, amorphous polyamide resin or fluororesin. This ensures that the fluorescent substance dispersed in the material emits light.

In the present invention, the fluorescent substance of the fluorescent member is preferably a yttrium aluminum garnet (YAG) type fluorescent substance.

In the present invention, the fluorescent member can contain various fluorescent substances such as inorganic fluorescent substances and organic fluorescent substances. An example of such a phosphor is a phosphor containing a rare earth element which is an inorganic phosphor, and specifically, at least one element selected from the group of Y, Lu, Sc, La, Gd and Sm. And a garnet-based (garnet-type) phosphor containing at least one element selected from the group consisting of Al, Ga and In. In particular, a cerium-activated yttrium aluminum oxide-based phosphor is preferable, and if desired, Pr, Pr,
Sm, Cu, Ag, Au, Fe, Cr, Nd, Dy, N
It is also possible to contain i, Ti, Tb and Eu. When both Ce and Pr are contained, a luminescent color having excellent color rendering properties can be obtained.

For example, as a semiconductor light emitting device, a high energy
A gallium nitride-based half
When using a light-emitting diode formed of a conductor, the present application
Described in Japanese Patent Application Laid-Open No. 10-112557
As you can see, it is activated with bivalent europium,
(M_1-p-qEu_pQ_q) O ・ n (Al_1-mB_m)
_TwoO_ThreeFluorescent substances having the chemical composition of are preferred. However
, 0.0001 ≦ p ≦ 0.5, 0.0001 ≦ q ≦
0.5, 0.5 ≦ n ≦ 10, 0 ≦ m ≦ 0.5, 0.00
02 ≦ p + q ≦ 0.75. In the composition, M is M
Is it a group of divalent metals consisting of g, Ca, Sr, Ba and Zn?
Q is at least one selected from the group consisting of co-activators
, Mn, Zr, Nb, Pr, Nd, Gd, Th, D
selected from the group consisting of y, Er, Tm, Yb and Lu
At least one kind.

When the fluorescent substance having the above composition is used, even if high energy light is generated for a long time in the visible light region, the fluorescent substance is not deteriorated and desired emission brightness and afterglow can be guaranteed for a long period of time.

Further, in the present invention, the fluorescent substance of the fluorescent member is preferably a nitride fluorescent substance having at least nitrogen as a basic element.

As an example of the nitride phosphor, L _X M _Y N
_{(2X / 3 + 4Y / 3)} : Z (L is Be, Mg, Ca,
At least one selected from the group consisting of II valences of Sr, Ba, Zn, Cd, and Hg. M is C, Si, Ge, Sn,
At least one selected from the group consisting of IV values of Ti, Zr, and Hf. Z is Eu, Cr, Mn, Pb, Sb, C
e, Tb, Pr, Sm, Tm, Ho, Er, Yb, Nd
At least one selected from the group consisting of: ) And the basic constituent elements represented by Mg), Sr, Ba, Zn, B, Al,
A nitride phosphor having at least one or more contained elements selected from the group consisting of Cu, Mn, Cr, O and Fe can be used. Such a nitride phosphor is
The inclusion of the contained element makes it possible to realize the adjustment of the particle size and the improvement of the emission brightness. Also, B, M
g, Cr, Ni, and Al have the effect of suppressing afterglow.

Further, the fluorescent substance may be one kind, or a mixture of two or more different kinds may be used.
In this case, it is preferable that the two or more types of fluorescent substances have complementary emission colors.

In one embodiment, the light emitting device includes a semiconductor light emitting element which emits a first light, a first fluorescent substance which is excited by a part of the first light and emits a second light, and And a second fluorescent substance that emits a third light when excited by a part of the first light. For example, a semiconductor light emitting element (main wavelength = 455 nm) that emits blue light is used, and the light from the semiconductor light emitting element is excited by light having a wavelength shorter than the main wavelength (excitation light = 440 nm), and a green light is emitted. Light (main wavelength = 530
nm) which is a first fluorescent substance capable of emitting Y.
_{3 (Al 0.8 Ga 0.2) 5} O 12: and Ce, first
Has a fluorescent substance nearly identical excitation light, a second fluorescent material capable of emitting red light (dominant wavelength _{= 650nm) (Sr 0.679 Ca 0.291} Eu
_0.03 ) ₂ Si ₅ N ₈ and a fluorescent member containing these three wavelengths (blue, green,
It is possible to realize a warm-colored white light-emitting device having an excellent color rendering property by mixing red (red) light.

Here, "white" in the present specification means
It means the color of the white area described in "JIS Z8110-1995 Reference Figure 1 General chromaticity classification of systematic color name".

Further, by combining a semiconductor light emitting element that emits light in the ultraviolet region and a plurality of fluorescent substances that absorb the light in the ultraviolet region and emits visible light, the light emitted from each fluorescent substance can be mixed. A warm white light emitting device can be realized.

When a plurality of fluorescent substances are used to form a color conversion multi-layer in which color conversion thin film layers each containing one kind of fluorescent substance are laminated, the ultraviolet light transmittance of each fluorescent substance is taken into consideration in each layer. It is preferable that the ultraviolet light transmittance of the fluorescent substance in the order is higher from the lower layer on the substrate side to the upper layer.

Further, it is preferable that the center particle diameter of the fluorescent substance in each layer is smaller in order from the lower layer on the substrate side to the upper layer. This makes it possible to efficiently irradiate even the uppermost fluorescent substance with ultraviolet light, and further prevent ultraviolet light from leaking to the outside of the device.

For example, when the red fluorescent substance, the blue fluorescent substance, and the green fluorescent substance listed above are used, it is preferable to stack the red fluorescent substance, the green fluorescent substance, and the blue fluorescent substance in this order from the substrate side. The central particle diameter of is preferably in the relationship of red fluorescent substance> green fluorescent substance> blue fluorescent substance.

Further, in the present invention, it is preferable that the fluorescent member contains a pigment having a body color similar to the emission color of the fluorescent substance. For example, in the emission spectrum of the semiconductor light emitting element, by using a pigment that can block light in a region that is not related to the complementary color of the emission color of the light emitting device or light that does not correspond to the excitation light of the fluorescent substance, The sharpness can be increased. At that time, the effect can be further enhanced by setting the body color of the pigment and the emission color of the fluorescent substance in the same color system.

In order to obtain the dispersed state of the fluorescent substance in the fluorescent member, the viscosity of the synthetic resin material is set so as to prevent the fluorescent substance from settling in the lower part of the reflector portion while suppressing the settling of the fluorescent substance as much as possible. It is preferable to use a resin.

That is, the fluorescent member has a viscosity of 2500 mPa · s.
~ 20,000 mPas, preferably 3000 mPas
s-10000 mPa · s, more preferably 4000 m
It is preferably formed using a transparent synthetic resin material of Pa · s to 8000 mPa · s.

The amount of the fluorescent substance can be determined according to the emission wavelength of the semiconductor light emitting device, the emission intensity and other conditions, but 40 parts by weight of the fluorescent substance to 100 parts by weight of the transparent synthetic resin material are used. 300 parts by weight, preferably 40 parts by weight
It is preferable to form the fluorescent member by using a material in which 200 parts by weight, more preferably 40 parts by weight to 100 parts by weight are mixed.

The larger the particle diameter of the fluorescent substance, the higher the efficiency of being excited by the light emitted from the semiconductor light emitting element to emit light, but the fluorescent substance is more likely to settle in the lower portion of the fluorescent member. Therefore, it is preferable that the fluorescent substance of the fluorescent member has an average particle diameter of 6 μm to 25 μm measured by the Fisher method.

The curved shape of the fluorescent member may be processed by a chemical treatment such as etching, but it can be self-formed by potting a transparent resin material mixed with a fluorescent substance, which simplifies the manufacturing process. Cost reduction can be achieved.

Further, in the present invention, it is preferable to provide a sealing resin for sealing the semiconductor light emitting element. The sealing resin is not particularly limited as long as it is a transparent resin material, and can be formed of, for example, an epoxy resin, a silicone resin, an amorphous polyamide resin, or a fluororesin.

Furthermore, by disposing a resin layer containing a diffusing agent above the semiconductor light emitting element by coating or the like, it is possible to more reliably prevent color unevenness and obtain a uniform emission color. As the diffusing agent, barium titanate, titanium oxide, aluminum oxide, silicon oxide, calcium carbonate,
One kind or two or more kinds of white carbon, talc and magnesium carbonate can be used.

Further, by disposing a condensing member for condensing light above the semiconductor light emitting element, for example, a single lens or a Fresnel lens, a desired light directivity can be easily obtained, and illumination can be performed. It can be used as a backlight light source for various devices such as appliances and signal lights. Also,
When a Fresnel lens or the like is used as the light collecting member, a thin light emitting device can be realized.

[0069]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings.

(First Embodiment) FIG. 1 shows a first embodiment according to the present invention. In FIG. 1, a semiconductor light emitting element 11 is mounted on a case bottom surface (base surface) 10 and electrodes 12 and 12 are provided. An electrode (not shown) of the semiconductor light emitting element 11 and an electrode on the case bottom surface 10 are provided. 12, 12
Are bonded by wires 13, 13.

On the bottom surface 10 of the case, a reflector portion 14 functioning as a fluorescent member is provided.
It is formed to surround the circumference of. This reflector part 1
4 is formed of a transparent resin material, and the reflector portion 1
The inner surface of 4 has a shape in which a substantially arcuate concave cross section extending in the height direction from the height of the case bottom surface 10 obliquely outward and upward is continuous over the entire circumference of a plane circular shape, a plane elliptical shape, or a plane oval shape. Is formed in.

The inner surface of the reflector portion 14 may be formed so as to substantially form a part of a paraboloid of revolution, a ellipsoid of revolution or a hyperboloid of revolution.

The reflector portion 14 has a semiconductor light emitting device 1
The YAG-based fluorescent material 15 that is excited by the emission of light from No. 1 to emit light is dispersed in the height direction of the reflector portion 14 so that the density gradually decreases from the case bottom surface 10 toward the surface.

When the light emitting device of this example is manufactured, for example, the semiconductor light emitting device 1 having a gallium nitride semiconductor in the light emitting layer 1
1, the semiconductor light emitting element 11 is die-bonded on the bottom surface 10 of the case using, for example, an epoxy resin, and the electrodes of the semiconductor light emitting element 11 and the electrodes 12, 1 on the bottom surface 10 of the case
2 is wire-bonded with, for example, gold wires 13 to secure electrical continuity. Since the method for manufacturing the semiconductor light emitting device 11 is the same as a known method, detailed description thereof will be omitted.

On the other hand, the fluorescent substance 15 has a thickness of 6 μm to 25 μm.
YAG fluorescent substance having an average particle size within the range of 40 to 100 parts by weight is used to obtain a viscosity of 2500 mP.
a · s to 20000 mPa · s, preferably 3000 m
Pa · s-10000 mPa · s, more preferably 40
The material of the reflector portion 14 is manufactured by mixing with 100 parts by weight of a transparent epoxy resin, a transparent silicone resin, a transparent amorphous polyamide resin or a transparent fluororesin of 00 mPa · s to 8000 mPa · s.

For example, when a white light is emitted from the light emitting device, the semiconductor light emitting element 11 that emits blue light is used, while the silicone resin 10 having a viscosity of 4000 mPa · s is used.
50 parts by weight of YAG: Ce fluorescent material having an average particle size of 7 μm that is excited by blue light and emits yellow light is mixed with 0 part by weight to manufacture the material of the reflector portion 14. When the material for the reflector portion 14 is prepared, potting is performed around the upper end of the side wall of the case, and when the resin flows downward and hardens, the reflector portion 1 having the inner surface shape shown in FIG. 1 is formed.
4 is obtained.

The entire reflector portion 14 in the height direction has a curved surface shape in which a substantially arcuate concave cross section which extends obliquely outward and upward from the height of the bottom surface 10 of the case is continued over substantially the entire circumference. In addition, a gap is formed between the inner edge of the lower end of the reflector portion 14 and the lateral end surface of the semiconductor light emitting element 11. Further, although the fluorescent substance 15 settles during the downward flow of the resin, the fluorescent substance 15 is unlikely to settle due to the viscosity of the resin, and when the resin is cured, it is directed from the lower portion of the reflector portion 14 to the surface as shown in FIG. Are dispersed so that the density gradually decreases.

Finally, the semiconductor light emitting device 11, the electrode 12,
When the 12 and the gold wires 13 and 13 are sealed with a sealing resin 16 such as a silicone resin, the light emitting device of this example is obtained, and thus the reflector portion 14 can be easily formed by a simple method of potting, and the productivity is flat. Significantly higher than conventional light-emitting devices with various reflectors.

When the blue light B is emitted from the semiconductor light emitting element 11, a part thereof is radiated forward, and a part thereof goes toward the curved surface of the reflector portion 14 and excites the fluorescent substance 15 of the reflector portion 14 to excite the fluorescent substance. Yellow light Y is emitted from 15 in an arbitrary direction. Further, the blue light B1 is also emitted from the side end surface of the semiconductor light emitting element 11, and the end surface emission B1 also goes to the curved surface of the reflector portion 14 to excite the fluorescent substance 15 of the reflector portion 14 to emit yellow light Y from the fluorescent substance 15. Are emitted in an arbitrary direction, the blue light B and the yellow light Y are mixed, and white light appears in front of the light emitting device.

At this time, since the output of yellow light is relatively low as compared with the output of blue light, in order to obtain a desired emission color with a desired light output, the width of the fluorescent substance 15 is made thicker or the reflector is used. -It is necessary to increase the creepage distance on the inner surface of part 14, but
In the light emitting device of this example, since the inner surface of the reflector portion 14 is formed into a curved surface shape, when the so-called cavity depth is the same, the creepage distance can be increased as compared with the conventional light emitting device having a flat reflector. Even a light emitting device having the same performance can be downsized.

In the light emitting device of the present embodiment as described above, most of the light emitted obliquely from the semiconductor light emitting element 11 and the edge light emission reach the fluorescent substance 15 of the reflector portion 14 and efficiently excite the fluorescent substance to emit light. Can be made. Moreover, since the fluorescent substance is not dispersed in the sealing resin 16, the light transmittance is high, and as a result, a high light output can be obtained.

As shown in FIG. 2, the light output c of the light emitting device of this example is the light output a of the light emitting device in which the YAG fluorescent substance is dispersed in the sealing resin and the fluorescent substance is allowed to settle at the bottom of the cavity. It was confirmed that the light output was significantly higher than the light output b of the light emitting device.

Further, since the reflector portion 14 has a curved surface shape, the light emitted obliquely from the semiconductor light emitting element 11 and the edge light emission are radiated in arbitrary directions by the reflector portion 14, so that a flat reflector structure is obtained. As a result, it is possible to obtain a uniform emission color that is easily scattered and has little color unevenness.

(Second Embodiment) FIG. 3 shows a second embodiment. In this example, a plurality of semiconductor light emitting elements 11 are mounted on the bottom surface 10 of the case in an arbitrary arrangement, and each semiconductor light emitting element 1
The reflector portion 14 is formed so as to surround the periphery of 1.
In this way, a plurality of structures according to the first embodiment can be arranged.

(Third Embodiment) FIG. 4 shows a third embodiment. In this example, the cavity wall portion 17 is formed on the bottom surface 10 of the case using a synthetic resin material, and the semiconductor light emitting device 11 is formed on the bottom surface 10 of the case surrounded by the cavity wall portion 17.
And the cavity wall 17 is used to form the reflector portion 14 by potting.

(Fourth Embodiment) FIG. 5 shows a fourth embodiment. In this example, a plurality of cavity wall portions 17 are formed in an arbitrary array on the case bottom surface 10 using a synthetic resin material, and the semiconductor light emitting element 11 is mounted on the case bottom surface 10 surrounded by each cavity wall portion 17. The cavity wall portion 17 is used to form the reflector portion 14 by potting. As described above, a plurality of structures according to the third embodiment can be arranged.

(Fifth Embodiment) FIG. 6 shows a fifth embodiment. In this example, on the front surface of the light emitting device of the second embodiment,
The diffusing agent layer 20 in which the diffusing agent 21 is dispersed in the transparent resin material as described above is formed. With such a structure, the light emitting element 11 emits light in the diffusing agent layer 20,
Light emission from the fluorescent substance 15 is more surely mixed with each other to prevent color unevenness.

The diffusing agent layer 20 may be similarly formed in the light emitting devices having the structures of the first, third and fourth embodiments.

(Sixth Embodiment) FIG. 7 shows a sixth embodiment according to the present invention. In FIG. 7, the semiconductor light emitting element 11 is mounted on the bottom surface (base surface) 10 of the case, and the electrodes 12 and 12 are provided. The electrodes (not shown) of the semiconductor light emitting element 11 and the electrodes on the bottom surface 10 of the case. 12, 12
Are bonded by wires 13, 13.

On the bottom surface 10 of the case, the cavity wall 17 functioning as a fluorescent member is provided with the semiconductor light emitting element 11.
The electrodes 12 and 12 are formed so as to surround the peripheries thereof. The cavity wall portion 17 is formed of a transparent resin material, and the cavity wall portion 17 is provided with a YAG-based fluorescent substance 15 which is excited by the light emitted from the semiconductor light emitting element 11 to emit light, in the height direction of the cavity wall portion 17. In, the density is gradually dispersed from the case bottom surface 10 toward the surface.

When the light emitting device of this example is manufactured, for example, the semiconductor light emitting device 1 having a gallium nitride based semiconductor in the light emitting layer 1
1, the semiconductor light emitting element 11 is die-bonded on the bottom surface 10 of the case using, for example, an epoxy resin, and the electrodes of the semiconductor light emitting element 11 and the electrodes 12, 1 on the bottom surface 10 of the case
2 is wire-bonded with, for example, gold wires 13 to secure electrical continuity. Since the method for manufacturing the semiconductor light emitting device 11 is the same as a known method, detailed description thereof will be omitted.

On the other hand, the fluorescent substance 15 has a thickness of 6 μm to 25 μm.
YAG fluorescent substance having an average particle size within the range of 40 to 100 parts by weight is used to obtain a viscosity of 2500 mP.
a · s to 20000 mPa · s, preferably 3000 m
Pa · s-10000 mPa · s, more preferably 40
The material of the cavity wall 17 is manufactured by mixing with 100 parts by weight of a transparent epoxy resin, a transparent silicone resin, a transparent amorphous polyamide resin or a transparent fluororesin of 00 mPa · s to 8000 mPa · s.

For example, when a white light is emitted from the light emitting device, the semiconductor light emitting element 11 that emits blue light is used, while the silicone resin 10 having a viscosity of 4000 mPa · s is used.
50 parts by weight of YAG: Ce fluorescent material having an average particle size of 7 μm that is excited by blue light and emits yellow light is mixed with 0 parts by weight to manufacture a material for the cavity wall 17.

When the material for the cavity wall portion 17 is prepared, as shown in FIGS. 8A and 8B, the molding wall 30 is provided on the bottom surface 10 of the case, and the semiconductor light emitting element 11 and the electrode 12 are provided. , 12, a metal box 31 is placed on the bottom surface 10 of the case, and when the material of the cavity wall portion 17 is injected into the gap between the both 30, 31, the gap between the molding wall 30 and the metal box 31 is filled. The material flows and fills.

When the injected material is hardened, the cavity wall 17 is obtained, but the fluorescent substance 15 is in a dispersed state in which the density gradually decreases from the base surface 10 toward the surface due to the viscosity of the synthetic resin material.

Finally, the semiconductor light emitting device 11, the electrode 12,
The light emitting device of this example is obtained by sealing 12 and the gold wires 13, 13 with a sealing resin 16 such as a silicone resin.

When the blue light B is emitted from the semiconductor light emitting element 11, a part thereof is radiated forward and a part thereof goes toward the cavity wall portion 17, and the fluorescent substance 15 in the cavity wall portion 17 is emitted.
And the yellow light Y is emitted from the fluorescent substance 15 in an arbitrary direction. Further, the blue light B1 is also emitted from the side end surface of the semiconductor light emitting element 11, and the end surface emission B1 also goes to the cavity wall portion 17, and the fluorescent material 15 of the cavity wall portion 17 is emitted.
And the yellow light Y is emitted from the fluorescent substance 15 in an arbitrary direction, the blue light B and the yellow light Y are mixed, and white light appears in front of the light emitting device.

In the light emitting device of the present embodiment as described above, most of the light emitted obliquely from the semiconductor light emitting element 11 and the end face light emission reach the fluorescent substance 15 of the cavity wall 17 to efficiently excite the fluorescent substance. It can emit light. Moreover, since the fluorescent substance is not dispersed in the sealing resin 16, the light transmittance is high, and as a result, a high light output can be obtained.

Further, the fluorescent material 1 is provided on the cavity wall portion 17.
Since 5 are dispersed so that the density gradually decreases from the base surface 10 toward the surface, the cavity wall portion 17 is functionally shaped so that the inner surface of the cavity wall portion has a curved shape with respect to light emission from the semiconductor light emitting element 11. As a result, the light emitted obliquely from the semiconductor light emitting element 11 and the edge light emission are radiated in arbitrary directions by the cavity wall 17,
Compared to the cavity structure coated with a fluorescent substance, the light is more likely to be scattered and a uniform emission color with less color unevenness can be obtained.

(Seventh Embodiment) The sixth embodiment is different from the sixth embodiment except that a plurality of fluorescent substances having different conversion efficiencies are laminated instead of adjusting the density of the fluorescent substance 15 in the cavity wall portion 17 functioning as a fluorescent member. Similar effects can be obtained when the light emitting device is configured in the same manner. For example, the first portion having a short distance from the semiconductor light emitting element 11 is composed of the first phosphor having a large activator content, and the second portion having a distance from the semiconductor light emitting element 11 is farther than the first portion is the first portion. It is possible to configure the second phosphor having a smaller activator content than that of the phosphor, whereby the semiconductor light emitting device 1 in the first portion is formed.
The absorption rate of the light emitted from 1 can be made higher than that of the second portion.

(Eighth Embodiment) Similar to the sixth embodiment except that the density of the light diffusing agent is adjusted instead of adjusting the density of the fluorescent substance 15 in the cavity wall portion 17 functioning as a fluorescent member. Similar effects can be obtained when the light emitting device is configured. For example, the density of the fluorescent material is uniformly dispersed in the translucent resin forming the cavity wall.
In this cavity wall portion, the density of the light diffusing agent contained in the first portion having a short distance from the semiconductor light emitting element 11 is larger than the density of the light diffusing agent contained in the second portion farther from the semiconductor light emitting element 11 than the first portion. To be configured. Thereby, the absorption rate of the light emitted from the semiconductor light emitting element 11 in the first portion can be made higher than that in the second portion.

(Ninth Embodiment) FIG. 9 shows a ninth embodiment. In this example, a plurality of semiconductor light emitting elements 11 are mounted on the bottom surface 10 of the case in an arbitrary arrangement, and each semiconductor light emitting element 1
1 and a cavity wall 1 surrounding the electrodes 12, 12.
Forming 7. In this way, a plurality of structures according to the first embodiment can be arranged.

(Tenth Embodiment) FIG. 10 shows a tenth embodiment. In this example, the diffusing agent layer 20 in which the diffusing agent 21 is dispersed in the transparent resin material as described above is formed on the front surface of the light emitting device of the second embodiment. With such a structure, the diffusing agent layer 20 is formed. In the above, the light emission from the semiconductor light emitting element 11 and the light emission from the fluorescent substance 15 are more surely mixed with each other, so that color unevenness can be prevented further. The diffusing agent layer 20 may be similarly formed in the light emitting device having the structure of the sixth embodiment.

In each of the above-described embodiments, an example in which the fluorescent material density in the fluorescent member such as the reflector portion and the cavity wall portion continuously changes according to the height from the base surface has been described. It may be changed to.

In each of the embodiments, two or more different types of fluorescent substances may be mixed in the fluorescent member such as the reflector portion and the cavity wall portion, and the fluorescent colors such that the emission colors of the fluorescent substances have a complementary color relationship. By selecting a substance, for example, the red fluorescent substance, the blue fluorescent substance, or the green fluorescent substance as described above, it is possible to realize white light emission by color mixing.

In each of the embodiments, the fluorescent member such as the reflector or the cavity wall may contain a pigment having a body color similar to the emission color of the fluorescent substance.

In each embodiment, a light condensing member such as a single lens or a Fresnel lens may be arranged on the light emitting surface side of the light emitting device.

[0108]

As described above in detail, the light emitting device according to the present invention is set so that the absorption rate of the light emitted from the semiconductor light emitting element becomes higher as the distance from the semiconductor light emitting element becomes closer to each part of the fluorescent member. By doing so, each part of the fluorescent member can be adapted to the amount of light emitted from the semiconductor light emitting element. As a result, in the entire fluorescent member, it is possible to make the ratio of the amount of light that is wavelength-converted in the fluorescent member almost equal to the amount of light emitted from the light emitting element, excellent color rendering, and uniform light emission with little color unevenness The color is obtained.

Further, since the fluorescent member formed by dispersing the fluorescent substance in the transparent resin material includes the curved surface shape that reflects the light emitted laterally from the semiconductor light emitting element in the direction away from the base surface, Uniform white light with little color unevenness can be obtained with high output.

Further, in the fluorescent member formed by dispersing the fluorescent substance in the transparent resin material, the fluorescent substance density changes continuously or stepwise according to the height from the base surface, and Uniform white light with less unevenness can be obtained with high output.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment according to the present invention.

FIG. 2 is an explanatory diagram comparing optical outputs.

FIG. 3 is a sectional view showing a second embodiment.

FIG. 4 is a cross-sectional view showing a third embodiment.

FIG. 5 is a sectional view showing a fourth embodiment.

FIG. 6 is a sectional view showing a fifth embodiment.

FIG. 7 is a sectional view showing a sixth embodiment according to the present invention.

8A is a plan view schematically showing a method of manufacturing a cavity wall portion in the embodiment shown in FIG.
(B) is the schematic sectional drawing.

FIG. 9 is a cross-sectional view showing a ninth embodiment.

FIG. 10 is a sectional view showing a tenth embodiment.

[Explanation of symbols]

10 Case bottom (base) 11 Semiconductor light emitting device 12 electrodes 13 wires 14 Reflector section 15 Fluorescent substance 17 Cavity wall 20 Diffusing agent layer 21 Diffusing agent

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4H001 CA05 XA07 XA08 XA13 XA14                       XA20 XA21 XA31 XA38 XA39                       XA49 XA57 XA62 XA64 XA71                       YA24 YA26 YA28 YA29 YA47                       YA58 YA59 YA60 YA62 YA63                       YA65 YA66 YA79 YA81                 5F041 AA04 AA11 CA14 CA40 DA07                       DA13 DA19 DA35 DA36 EE25                       FF01 FF11

Claims (27)

[Claims] 1. A semiconductor light emitting element which emits at least a part of light emission from a side end surface, and a fluorescent member which is arranged apart from the semiconductor light emitting element, wherein the fluorescent member emits light emitted from the semiconductor light emitting element. It can absorb a part of the light and convert it to other light to emit light.
At least one element selected from the group consisting of u, Sc, La, Gd and Sm, at least one element selected from the group consisting of Al, Ga and In, and at least Ce together with Pr, Sm, Cu, Ag, Au, Fe, Cr, N
At least one element selected from the group consisting of d, Dy, Ni, Ti, Tb, and Eu is included as a constituent member, and the fluorescent member is located at a first distance from the semiconductor light emitting device. And a second portion located at a position farther than the first distance, wherein the first portion has a higher absorption rate of light emitted from the semiconductor light emitting element than the second portion. apparatus. 2. A semiconductor light emitting element which emits at least a part of light emission from a side end surface, and a fluorescent member which is arranged apart from the semiconductor light emitting element, wherein the fluorescent member emits light emitted from the semiconductor light emitting element. The fluorescent member can absorb a part of the light and convert it into other light to emit light. The fluorescent member has a first portion located at a first distance from the semiconductor light emitting element and a second portion located at a position farther than the first distance. The first light emitting device has a higher absorption rate of light emitted from the semiconductor light emitting element than that of the second light emitting device. 3. The fluorescent member is formed of a translucent member in which a fluorescent substance is dispersed, and the absorptance is adjusted continuously or stepwise according to the absolute amount of the fluorescent substance. The light emitting device according to claim 2. 4. The light emitting device according to claim 3, wherein in the fluorescent member, the density of the fluorescent material in the first portion is higher than that in the second portion. 5. The fluorescent member is configured by stacking a plurality of types of fluorescent substances, and the absorptance is adjusted according to the light conversion efficiency of each fluorescent substance. Light emitting device. 6. The fluorescent member includes at least a fluorescent substance and a light diffusing agent as constituent members, and the absorptance is adjusted according to the density of the light diffusing agent. Light emitting device. 7. The light emitting device according to claim 6, wherein in the fluorescent member, the first portion has a higher density of the light diffusing agent than the second portion. 8. The light emitting device according to claim 2, wherein the fluorescent member is disposed on a lateral end surface of the semiconductor light emitting device and includes a flat shape or a curved shape capable of reflecting light emitted from the semiconductor light emitting device. apparatus. 9. The light emitting device according to claim 2, wherein mixed light of visible light from the semiconductor light emitting element and visible light from the fluorescent material is generated. 10. The light emitting device according to claim 9, wherein the mixed color light is white light. 11. An electrode provided on a base surface, a semiconductor light emitting element which is mounted on the base surface with a gap from the electrode and emits a part of light emission from a side end surface, the semiconductor light emitting element and the electrode. A connecting member for electrically connecting, and a fluorescent member formed of a transparent resin material in which a fluorescent substance that is excited by the light emitted from the semiconductor light emitting element to emit light is dispersed, and arranged so as to surround the semiconductor light emitting element. The fluorescent member includes a curved surface shape that reflects light emitted laterally from the semiconductor light emitting element in a direction away from the base surface. 12. The light emitting device according to claim 11, wherein the inner surface of the fluorescent member is formed to substantially form a part of a paraboloid of revolution, a spheroid of revolution, or a hyperboloid of revolution. 13. An electrode provided on a base surface, a semiconductor light emitting element which is mounted on the base surface with a gap from the electrode and emits a part of light emission from a lateral end surface, the semiconductor light emitting element and the electrode. A connecting member for electrically connecting, and a fluorescent member formed of a transparent resin material in which a fluorescent substance that is excited by the light emitted from the semiconductor light emitting element to emit light is dispersed, and arranged so as to surround the semiconductor light emitting element. The light emitting device characterized in that the density of the fluorescent substance in the fluorescent member changes continuously or stepwise according to the height from the base surface. 14. The light emitting device according to claim 13, wherein the fluorescent substance density in the fluorescent member increases as the height from the base surface decreases. 15. The light emitting device according to claim 11, wherein the transparent resin material of the fluorescent member is an epoxy resin, a silicone resin, an amorphous polyamide resin, or a fluororesin. 16. The light emitting device according to claim 11, wherein the fluorescent substance of the fluorescent member is a yttrium aluminum garnet type fluorescent substance. 17. The light emitting device according to claim 11, wherein the fluorescent material of the fluorescent member is a nitride fluorescent material having at least nitrogen as a basic element. 18. The light emitting device according to claim 11, wherein the fluorescent substance of the fluorescent member is a mixture of two or more different types of fluorescent substances. 19. The two or more types of fluorescent substances are characterized in that their emission colors are in a complementary color relationship.
8. The light emitting device according to item 8. 20. The light emitting device according to claim 11, wherein the fluorescent member contains a pigment having a body color similar to the emission color of the fluorescent substance. 21. The fluorescent member has a viscosity of 2500 mPa · s.
The light emitting device according to claim 11 or 13, wherein the light emitting device is formed using a transparent resin material of 20,000 mPa · s. 22. The fluorescent member is formed by using a material obtained by mixing 40 parts by weight to 100 parts by weight of a fluorescent substance with 100 parts by weight of a transparent resin material.
Or the light-emitting device according to item 13. 23. The fluorescent material of the fluorescent member has an average particle size of 6 μm.
The light emitting device according to claim 11 or 13, having a thickness of m to 25 µm. 24. The light emitting device according to claim 11, wherein the fluorescent member has a shape self-formed by potting a transparent resin material mixed with a fluorescent substance. 25. The light emitting device according to claim 11, further comprising a sealing resin for sealing the semiconductor light emitting element. 26. The light emitting device according to claim 11, wherein a light diffusing member for diffusing light is provided above the semiconductor light emitting element. 27. The light emitting device according to claim 11, wherein a light collecting member for collecting light is provided above the semiconductor light emitting element.