JP2001077433A - Light-emitting device and formation method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance contrast ratio by a method, wherein the relations between the fluorescent materials, a light-transmitting molding member, and the optical diffusion agents are set, so that the specific gravities of the fluorescent materials become higher than those of the molding member and the diffusion agents. SOLUTION: Fluorescent materials 101 are contained in a material, which is used as a light-emitting molding member 103, along with light-diffusion agents 102 and stirred. Here, the materials 101 colored in a chromatic color, such as a red color or a yellow color, are selected in ones of a specific gravity higher than the specific gravities of the agents 102 and the specific gravity of a resin, where the materials 101 are made to contain. Whereupon, the high-specific gravity materials 101 are settled out on the side of a light-emitting element 106 by reduction in the viscosity of the resin, which is generated at curing of the resin or the like, and the difference between the specific gravities of the agents 102 an the materials 101. The agents 102 are scattered or are distributed in the side of the surface, which opposes to the element 106 of the member 103. Accordingly, as the agents 102 relax the color of the materials 101 of the colored color from the side of the emission observation surface of a light- emitting device, of since the color of the materials 101 results in being seen in an achromatic color, the contrast between the materials 101 and the agents 102 is enhanced.

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 using a light emitting element and a phosphor for converting the wavelength of the light emitting element. In particular, the present invention relates to a light emitting device having a high contrast ratio and a high light extraction efficiency and excellent mass productivity. To provide.

[0002]

2. Description of the Related Art Applicants have developed a blue LED which emits light with high luminance.
Was developed. In addition, as an applied product, an LED chip that can emit blue light and a phosphor that absorbs light from the LED chip and emits yellow light are combined, and the color mixture of blue light from the LED chip and yellow light from the phosphor As a result, a light emitting diode capable of emitting white light has been put to practical use.

[0003] Specifically, as a light emitting diode capable of emitting white light, an LED chip is arranged in a concave portion of a resin substrate, and the LED chip absorbs blue visible light from the LED chip and emits yellow fluorescent light. It is covered with a translucent resin containing a phosphor that emits light. By passing a current through the LED chip, white light can be emitted with a relatively simple configuration of a one-chip two-terminal structure. For this reason, it has begun to be rapidly used in the market as a white light emitting diode.

[0004] Such a phosphor is colored chromatically because it absorbs visible light and emits visible light. As described above, a phosphor that emits yellow light emits fluorescent light when irradiated with extraneous light. The body itself looks yellow. Therefore, when viewed from the light emission observing surface side of the light emitting diode, the surface of the light emitting diode can be seen in the color of the phosphor, and the entire resin containing the phosphor appears to emit yellow light by itself from outside. Therefore, the contrast ratio between when the light emitting element is turned on and when it is not turned on is deteriorated. Further, in the case of a yellow phosphor or a red phosphor, the light emission observation surface side looks yellow or red and becomes a cautionary color or a dangerous color. Therefore, it is not preferable to use such a light emitting diode for a display in view of visibility. As one method of improving such a contrast ratio or the like, it is conceivable to coat a resin containing a phosphor with a resin containing a light diffusing agent.

[0005]

However, in the case of sealing with a resin containing a light diffusing agent separately from the resin containing the phosphor, the forming process becomes complicated and mass productivity is low. Further, at the present time when a light-emitting device of a smaller size is required, there is a problem that it is extremely difficult to form a different resin with high accuracy, and the yield tends to decrease. Accordingly, the present invention is to solve such a problem and to provide a light emitting device which is excellent in mass productivity and has an excellent contrast ratio, and a method for forming the same.

[0006]

SUMMARY OF THE INVENTION The present invention provides a semiconductor light emitting device that emits visible light, a light transmitting mold member that covers the semiconductor light emitting device, and a semiconductor light emitting device contained in the light transmitting mold member. And a light-diffusing agent that absorbs visible light and emits visible light having a longer wavelength than the visible light. In particular, in the present invention, the relationship between the phosphor, the translucent mold member, and the diffusing agent is such that the specific gravity of the phosphor is greater than that of the translucent mold member and the light diffusing agent.

Thus, a light emitting device having a high contrast ratio can be formed relatively easily. Further, a light emitting device capable of emitting white light can be provided while further reducing the amount of phosphor used. Further, a light-emitting device with high reliability can be provided even in repeated use.

Further, in the light emitting device according to the second aspect, the particle diameter of the phosphor is 1 μm or more and 100 μm or less. This makes it possible to provide a light-emitting device that is more excellent in mass productivity and luminous efficiency. Further, in a light emitting device that emits light from a semiconductor light emitting element and combined light from a phosphor, a light emitting device with less color unevenness and luminance unevenness can be provided.

According to a third aspect of the present invention, in the light emitting device, the phosphor is C
It was activated by _{e (Y 2 O 3 · 5} / 3Al 2 O 3) YAG, E
nitrogen-containing CaO-Al ₂ O activated with u and / or Cr
₃ is a one selected from -SiO _2. This makes it possible to provide a simple and highly reliable light emitting device capable of emitting mixed colors with high luminance.

[0010] According to a fourth aspect of the present invention, there is provided a method for forming a light emitting device.
A semiconductor light-emitting element that emits visible light, a light-transmissive mold member that covers the semiconductor light-emitting element, and a light-transmissive mold member that absorbs visible light from the semiconductor light-emitting element and has a longer wavelength than the visible light. This is a method for forming a light emitting device including a phosphor that emits visible light and a light diffusing agent. In particular, the step of including a phosphor having a higher specific gravity than the light-transmitting mold member and the light diffusing agent in the material to be the light-transmitting mold member, and the step of transmitting the light diffusing agent and the phosphor on the semiconductor light emitting element. The method includes a step of coating a material to be a light-transmissive mold member, and a step of curing after reducing the viscosity of the material to be a light-transmissive mold member. This makes it possible to relatively easily form a light emitting device with a small amount of phosphor used and excellent color mixing properties with a high yield.

[0011] According to a fifth aspect of the invention, there is provided a method for forming a light emitting device.
A semiconductor light-emitting element that emits visible light, a light-transmissive mold member that covers the semiconductor light-emitting element, and a light-transmissive mold member that absorbs visible light from the semiconductor light-emitting element and has a longer wavelength than the visible light. This is a method for forming a light emitting device including a phosphor that emits visible light and a light diffusing agent. In particular, the present invention relates to a method for forming a light emitting device including a step of separating a distribution state of a light diffusing agent and a phosphor in a material to be a translucent mold member and a step of curing the material to be a translucent mold member. This makes it possible to relatively easily form a light emitting device with a small amount of phosphor used and excellent color mixing properties with a high yield. Further, the contrast can be adjusted with good controllability.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION As a result of various experiments, the present inventor has determined that the specific gravities of the phosphor, the light diffusing agent and the resin containing them are in a specific relationship, thereby achieving a high reliability by a relatively simple method. The inventors have found that a light emitting diode can be formed, and have made the present invention.

That is, a phosphor colored in a chromatic color such as red or yellow is selected to have a higher specific gravity than the light diffusing agent or the resin containing the phosphor. A phosphor and a light diffusing agent are contained in the resin selected in this manner, and the light emitting element is coated and cured with these. Due to a decrease in resin viscosity and a difference in specific gravity caused when the resin is cured, a phosphor having a large specific gravity sinks to the light emitting element side. On the other hand, the light diffusing agent is dispersed or distributed on the surface side facing the light emitting element. Therefore, from the emission observation surface side, the color of the chromatic phosphor is relaxed by the light diffusing agent or looks achromatic. Hereinafter, specific embodiments of the present invention will be described in detail, but needless to say, the present invention is not limited thereto. (Embodiment Example 1) Chip type L which is the light emitting device 100
ED is shown as an example. A lead electrode formed by punching a metal flat plate is arranged in a mold, and resin is insert-molded. Thus, a package in which the light emitting element is arranged can be formed.

In the package, a cavity may be formed in order to efficiently collect light from the light emitting element, and the light emitting element may be arranged in the cavity. Further, a flat substrate having a pair of opposed electrodes can be used without forming a cavity serving as a reflecting mirror. When a flat substrate is used, the light emitting device of the present invention can be formed by using a stencil printing method or the like. As such a package, various resins such as a liquid crystal polymer, a glass epoxy resin substrate, and a ceramic substrate can be used as desired.

In the first embodiment, as shown in the cross-sectional view of FIG. 1, a package having a cavity 104 serving as a concave portion on the surface and having a pair of opposed lead electrodes 105 exposed inside the cavity 104 was used. The pair of opposing lead electrodes 105 are formed using a metal flat plate such as the above-described iron-containing copper. The lead electrode 105 is connected to the cavity 104
It extends from the bottom surface side to the side surface of the package, and functions to supply an external current to the LED chip 106 serving as a light emitting element.

In order to excite the phosphor 101 by light emission from the LED chip 106, the LED chip 106
Light having a shorter wavelength is more efficient than light emitted from the phosphor 101. Therefore, As the LED chip 106 may utilize a variety of materials and structures, as capable of emitting semiconductor elements high visible light emission luminance with high efficiency, a nitride semiconductor _{(In x Ga y Al 1-} xy N , 0 ≦ x
.Ltoreq.1, 0.ltoreq.y.ltoreq.1) are preferably used for the light emitting layer. A light emitting device using a nitride semiconductor can be formed on a sapphire substrate, a spinel substrate, a single crystal of SiC or GaN, etc. Those having n-type and p-type nitride semiconductors are preferable.
When n-type and p-type nitride semiconductors are formed on a sapphire substrate which is an insulating substrate, the n-type and p-type
Each electrode is formed on the same surface side by exposing the mold nitride semiconductor.

The LED chip 106 thus formed is die-bonded inside the package using epoxy resin, and the lead electrodes 105 provided on the package are fixed.
And the electrodes of the LED chip are wire-bonded using gold wires, respectively (FIG. 1A). In addition, in the case of a flip-chip type light emitting element, the lead electrode and the light emitting element can be electrically connected by using solder, Ag paste, or the like, in addition to a wire.

On the other hand, as the phosphor 101 used in the present invention, various kinds of substances capable of absorbing visible light and emitting visible light can be used. In particular, blue visible light from the LED chip 106,
When forming a light emitting diode capable of emitting white light using mixed color with yellow visible light from the phosphor 101, Zn
ZnS-based phosphors (specific gravity 4 to 5) such as S: Ag, Cl and ZnS: Cu, Al; and YAG (Y ₂ ) such as YAG: Ce
_{O 3 · 5 / 3Al 2 O} 3) based phosphor (specific gravity 4 7) or the like can be used.

Other phosphors capable of absorbing blue, blue-green or green and emitting red light include sapphire (aluminum oxide) phosphor activated with Eu and / or Cr, and Eu.
And / or Cr-activated CaO-Al ₂ O ₃ -containing nitrogen
SiO ₂ phosphor (oxynitride fluorescent glass) and the like. Using these phosphors, white light can also be obtained by mixing colors of light from the light emitting element and light from the phosphors. In addition, not only fluorescent pigments but also fluorescent dyes can be used as long as the specific gravity difference of the present invention is satisfied. Organic phosphors that are fluorescent dyes generally have higher luminous efficiency than inorganic phosphors. However, it is difficult to make the difference in specific gravity large, and in consideration of mass productivity, a fluorescent pigment is more preferable. In addition,
When an organic photodye is used, a perylene derivative or the like can be suitably used. In addition, desired color rendering properties and colors can be obtained by appropriately combining these phosphors.

The phosphor of the present invention can be variously selected in order to utilize a specific gravity difference between a light-transmitting mold member containing the phosphor at the time of formation and a light diffusing agent that makes the color of the phosphor apparently disappear. Further, in order to further improve the mass productivity at the time of formation, the viscosity of the translucent mold member 103 containing the phosphor 101 and the light diffusing agent 102 and the particle size of the phosphor 101 are affected. That is, when the viscosity of the material forming the light-transmitting mold member 103 is low or when the particle size of the phosphor 101 is large, the separation and sedimentation due to the difference in specific gravity from the material forming the light-transmitting mold member 103 tends to be promoted. . In addition, when the particle diameter of the inorganic phosphor 101 is reduced due to crystal destruction in the pulverizing step, the conversion efficiency tends to decrease. further,
If the particle size is too small, an agglomerate is formed, so that the dispersibility in the translucent mold resin member is reduced, which tends to cause color unevenness and luminance unevenness from the light emitting device.

Therefore, the average particle diameter of the phosphor 101 is preferably 1 to 100 μm, more preferably 5 to 20 μm, although it depends on the material of the light-transmitting mold member 103 and the phosphor 101. As a specific phosphor 101 used in the present invention,
YAG-based phosphor activated by Ce (Y, Lu, Sc, L
A cerium-activated garnet-based phosphor containing at least one element selected from a, Gd, and Sm and at least one element selected from the group consisting of Al, Ga, and In). YAG phosphors are Y, G
A solution of a rare earth element of d and Ce dissolved in an acid in a stoichiometric ratio is precipitated with oxalic acid. A co-precipitated oxide obtained by calcining this is mixed with aluminum oxide to obtain a mixed raw material. This was mixed with ammonium fluoride as a flux, packed in a crucible, and fired in air at 1400 ° C. for 170 minutes to obtain a fired product. The fired product can be ball-milled in water, washed, separated, dried, and finally passed through a sieve to form a YAG phosphor. As the YAG phosphor of the first embodiment, (Y _0.8 Gd _0.2 ) ₃ Al ₅ O ₁₂ : Ce is used. This phosphor 101 has a specific gravity of about 5.0 and an average particle size of 5
μm.

Similarly, another specific phosphor used in the present invention is a nitrogen-containing CaO—Al ₂ O ₃ —SiO ₂ phosphor activated with Eu and / or Cr. This E
nitrogen-containing CaO-Al ₂ O activated with u and / or Cr
_{The 3-} SiO ₂ phosphor is prepared by mixing a powder obtained by mixing a rare earth material with a material such as aluminum oxide, yttrium oxide, silicon nitride, and calcium oxide at a predetermined ratio in a nitrogen atmosphere.
It is melted and molded at 300 ° C. to 1900 ° C. (more preferably 1500 ° C. to 1750 ° C.). The molded article can be ball-milled, washed, separated, dried, and finally passed through a sieve to form the phosphor. Thus, Ca-Al-Si-ON-based oxynitride fluorescence activated by Eu and / or Cr capable of emitting red light emission by an excitation spectrum having a peak at 450 nm and a blue light having a peak at about 650 nm. It can be glass.

In addition, C activated by Eu and / or Cr
By increasing or decreasing the nitrogen content of the a-Al-Si-ON-based oxynitride fluorescent glass, the peak of the emission spectrum can be continuously shifted from 575 nm to 690 nm. Similarly, the excitation spectrum can be shifted continuously. Therefore, white light can be emitted by combined light of a gallium nitride-based compound semiconductor containing GaN or InGaN doped with an impurity such as Mg or Zn in a light-emitting layer and light of a phosphor of about 580 nm. In particular, I which can emit light of about 490 nm with high luminance
Light emission can be obtained ideally in combination with a light-emitting element made of a gallium nitride-based compound semiconductor containing nGaN in the light-emitting layer.

Further, the above-described YAG-based phosphor activated by Ce and the nitrogen-containing Ca-activated by Eu and / or Cr are used.
Combination with Al-Si-ON-based oxynitride fluorescent glass makes use of a light-emitting element capable of emitting blue light to emit light with extremely high color rendering properties including RGB (red, green, blue) components at high luminance. A diode can also be formed. For this reason, an arbitrary intermediate color can be formed very simply by adding a desired pigment. In the present invention, any of the phosphors is an inorganic phosphor, and a light emitting diode having both high contrast and excellent mass productivity can be formed by using an organic light scattering agent or SiO ₂ .

The phosphor 101 is contained together with the light diffusing agent 102 in a material for the light-transmitting mold member 103 and is stirred. Here, the light diffusing agent 102 used in the present invention has a lower specific gravity than the phosphor 101, and the phosphor 101
Is made difficult to visually recognize from outside. Therefore, when the light diffusing agent 10 is contained in the translucent mold member 103, the light diffusing agent 10 has a color that looks white or has a complementary color.
2, it is possible to make gray or black achromatic.

As the light diffusing agent 102, the one having a larger difference in specific gravity from the phosphor 101 is more excellent in mass productivity. Among them, the light diffusing agent 1 smaller than the specific gravity of the translucent mold member 103
By selecting 02, the light diffusing agent 102 floats on the surface of the translucent mold member 103. This is phosphor 101
, The phosphor 101 and the light diffusing agent 10
Light-transmitting layer containing no 2 and light diffusing agent 103
Appears separately in the layer containing. Apparently, by using three or more layers, the effect of concealing the color of the phosphor itself becomes better than that in which the light diffusing agent and the phosphor are uniformly contained.

Further, the light emitted from the LED chip 106 is reflected by the layer containing the light diffusing agent 102.
Therefore, the optical path length of light becomes substantially longer in a portion that looks like a layer containing the phosphor 101. Therefore, the content of the phosphor 101 can be reduced as compared with a light emitting diode formed similarly except that the light diffusing agent is not contained. In addition, there is an excellent feature that color mixing of light emitted from the phosphor 101 and the LED chip 106 is increased, so that more uniform mixed light can be easily obtained. Note that the selection of the light diffusing agent 102 greatly changes depending on not only the specific gravity but also the refractive index and the particle size. That is, the light transmitting mold member 103 and the light diffusing agent 1
As the difference in the refractive index from that of 02 increases, the light extraction efficiency tends to increase. Further, the smaller the particle size of the light diffusing agent 102, the higher the light extraction efficiency tends to be. On the other hand, if the average particle size of the light diffusing agent 102 is too small, the transparency becomes high even if the light diffusing agent 102 is contained in the translucent mold member 103 in a large amount. Therefore, the average particle size of the light diffusing agent 102 is preferably larger than 0.5 μm and smaller than 10 μm. More preferably, the average particle size is larger than 0.5 μm and smaller than 5 μm.

As the light diffusing agent 102, specifically, silicon dioxide (specific gravity 2.2), calcium carbonate (specific gravity 2.9)
3) a light diffusing agent comprising an inorganic powder such as titanium oxide (specific gravity 4.26), zinc oxide (specific gravity 5.8), aluminum oxide (specific gravity 3.9), barium titanate (specific gravity 5.5); Epoxy resin (specific gravity 1.2), phenol / formalin resin (specific gravity 1.2), benzoguanamine resin (specific gravity 1.4), melamine resin (specific gravity 1.4), acrylic resin (specific gravity 1.2), polycarbonate resin ( Specific gravity 1.
2) Light-diffusing agents composed of organic powders such as polyethylene resin (specific gravity 0.95) and polypropylene resin (specific gravity 0.9).

On the other hand, it is preferable that the light-transmitting mold member has high light resistance to light from the light-emitting element and the phosphor and has excellent light-transmitting property. In addition, when acting as a protective film for covering a light emitting element, a certain degree of rigidity is required. Specific examples of the material of the translucent mold member include an epoxy resin (specific gravity 1.2), a silicone resin (specific gravity 1.0), a urethane resin (specific gravity 1.2), an unsaturated polyester resin (specific gravity 1.2), A non-solvent such as an acrylic urethane resin (specific gravity 1.2) and a polyimide resin (specific gravity 1.3) or a solvent-type liquid translucent thermosetting resin is preferably used. Similarly, acrylic resin (specific gravity 1.2), polycarbonate resin (specific gravity 1.2), polynorbornene resin (specific gravity 1.
Solvent-type liquid translucent thermoplastic resins such as 1) can also be used. Furthermore, not only organic substances but also inorganic substances such as silicon dioxide, and hybrid resins obtained by mixing silicon dioxide formed by a sol-gel method and acrylic resin can be suitably used.

When the translucent mold member 103 is provided on the outermost surface side of the light emitting device and it is necessary to protect the inside from the external environment, a useless liquid thermosetting resin can be suitably used. . On the other hand, the translucent mold member 10
In the case where 3 is further covered with a resin or the like, the resin described above can be variously selected and used in consideration of the adhesion to the translucent mold member 103.

Specifically, a melamine resin (specific gravity 1.4) is used as the light diffusing agent 102 as a fluorescent material, and (Y _0.8 Gd _0.2 ) ₃
Al ₅ O ₁₂ : Ce (specific gravity 5.1), contained in an epoxy resin (specific gravity 1.2) as a light-transmitting mold member, and stirred. At this time, the viscosity of the epoxy resin is 700 cp. In this state, the phosphor and the light diffusing agent are mixed so as to be substantially uniformly dispersed in the resin to be the light-transmitting mold member.

An epoxy resin in which a light diffusing agent and a phosphor are mixed and stirred is dropped into a cavity of a package in which a light emitting element and a lead electrode are electrically connected and fixed in advance. FIG. 1B is a schematic cross-sectional view of the light emitting device immediately after this.
Shown in This is first cured at 85 ° C. for 180 minutes, 140 ° C.
The light emitting device was formed by secondary curing for 40 minutes. When the formed light emitting device was observed from the light emission observation surface side, the light emission observation surface side was gray and achromatic, and even when external light was irradiated, the contrast ratio did not decrease and the appearance was excellent.

As a result of analyzing the formed light emitting device, as shown in the cross section of FIG. 1C, the concentration of the phosphor increases as the light emitting device is approached inside the cavity, and the light diffusing agent faces the light emitting device. It gradually increases on the front side.

The light emitting device of the present invention contains a light diffusing agent.
Reduce the amount of phosphor used compared to the case without
And color mixing is excellent. (Embodiment 2) As the phosphor 201, Y_ThreeAl_FiveO₁₂:
Ce, polycarbonate as the light diffusing agent 202 (specific gravity
1.2), an acrylic tree as the light-transmitting mold member 103
Using a fat (specific gravity 1.2), the light source shown in the schematic sectional view of FIG.
An optical device can be formed. This light emitting device 200
Converts the above-mentioned phosphor 201 and light diffusing agent 202 into a translucent mode.
After mixing in the material that will become the
Was. In this state, the material that becomes the translucent mold member 203 is
By curing and removing the stencil (not shown)
Can be formed. The light emitting device of the embodiment 2
A light emitting device having a high contrast ratio as in the first embodiment.
Can be Note that the light emitting element 206 in FIG.
Blue light emitting layer made of InGaN on C substrate
Are LED chips that can emit light, and the LED chip 206
Each electrode and the lead electrode 205 are connected to a conductive wire, respectively.
Using gold wire 207 and Ag paste 208
Are connected. In the present invention, the chip
Although the type LED has been described in detail, the lamp type LED
Needless to say, it can be applied to (Example of embodiment
3) Different colors in the visible emission spectrum of the same excitation light source
Embodiment example except that two kinds of phosphors capable of emitting light were used.
A light emitting device was formed in the same manner as in No. 2. Two types of phosphors
Has a particle size of 7.3 μm (Y_0.995Gd_0.005)_ThreeA
l_FiveO ₁₂: Ce_0.25And nitrogen activated by Eu and Cr
CaO-Al content_TwoO_Three-SiO_TwoA phosphor is used. This
Has a higher contrast ratio than that of the second embodiment.
Light emitting device can be obtained. This is a phosphor
It is thought that the body colors yellow and red are mixed
It is. The light emitting device of this embodiment is different from that of the embodiment 2.
By mixing pink pigments with high color rendering properties
Thus, the intermediate colors can also emit light with high luminance.

[0035]

As described above, it is possible to form a light emitting device using a phosphor with high mass productivity and high uniformity. Also, the uniformity of the light emitting device formed tends to be higher than when the light diffusing agent-containing resin and the phosphor-containing resin are separately formed. This is presumably because in the case of sequential formation, there is no variation in the amount due to a change with time of the resin viscosity or the like in the present invention. Further, the present invention has an excellent feature that the amount of phosphor used can be reduced.

[Brief description of the drawings]

FIG. 1 shows a schematic sectional view of the present invention.

FIG. 2 shows another schematic sectional view of the present invention.

[Explanation of symbols]

 100, 200: Light-emitting device 101, 201: Phosphor 102, 201: Light diffusing agent 103, 203: Translucent mold member 104: Cavity 105, 205: Lead electrode 106, 206 ... LED chip 107, 207: Conductive wire 108 ... cured conductive paste

Claims (5)

[Claims] 1. A semiconductor light emitting device that emits visible light, a light transmitting mold member that covers the semiconductor light emitting device, and a device that absorbs visible light from the semiconductor light emitting device contained in the light transmitting mold member. A light emitting device having a phosphor and a light diffusing agent that emit visible light having a wavelength longer than that of the visible light, wherein the phosphor has a specific gravity greater than that of the light transmitting mold member and the light diffusing agent. A light emitting device characterized by the above-mentioned. 2. The phosphor has a particle size of 1 μm to 100 μm.
The light emitting device according to claim 1, wherein the size is not more than μm. 3. The phosphor according to claim ₂ , wherein the phosphor is Y ₂ O ₃ activated with Ce.
_3. The light emitting device according to claim 1, wherein the light emitting device is one selected from nitrogen-containing CaO—Al ₂ O ₃ —SiO ₂ activated with 5/3 Al ₂ O ₃ , Eu and / or Cr. 4. 4. A semiconductor light emitting device that emits visible light, a light transmitting mold member that covers the semiconductor light emitting device, and a device that absorbs visible light from the semiconductor light emitting device contained in the light transmitting mold member. A method for forming a light-emitting device comprising a phosphor and a light-diffusing agent that emits visible light having a wavelength longer than that of visible light, wherein the light-diffusing agent and the light-diffusing agent are contained in the material to be the light-transmitting mold member A step of including a phosphor having a specific gravity greater than that of the light-transmissive mold member; and a step of coating the semiconductor light-emitting element with a light-transmissive mold member containing a light-diffusing agent and a phosphor. Curing the material after reducing the viscosity of the material. 5. A semiconductor light emitting device that emits visible light, a light transmitting mold member that covers the semiconductor light emitting device, and a device that absorbs visible light from the semiconductor light emitting device contained in the light transmitting mold member. A method for forming a light-emitting device comprising a phosphor and a light-diffusing agent that emits visible light having a wavelength longer than that of visible light, wherein the light-diffusing agent and the light-diffusing agent are contained in the material to be the light-transmitting mold member A step of including a phosphor having a specific gravity greater than that of the light-transmissive mold member; and a step of coating the semiconductor light-emitting element with a light-transmissive mold member containing a light-diffusing agent and a phosphor. A method for forming a light emitting device, comprising: a step of separating a distribution state of a light diffusing agent and a phosphor in a material; and a step of curing a material to be the light-transmitting mold member.