JP2018137473A - Light-emitting device and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a light-emitting device of which the luminescent chromaticity is corrected in accordance with a principle different from the prior arts or of a light-emitting device of which the luminescent chromaticity can be corrected in accordance with a principle different from the prior arts.SOLUTION: A light-emitting device comprises: a light-emitting element (10) which emits a visible light; a phosphor (27) for emitting a visible light that is excited by the light of the light-emitting element (10); a translucent member (20) which is located on the light-emitting element (10) and provided on the phosphor (27) or while including the phosphor (27) and includes a translucent base material (25); and a coating (40) that is provided on a top face of the translucent member (20) and configured by coagulating nanoparticles (30) of which the refraction factor is different from that of the base material (21).SELECTED DRAWING: Figure 1

Description

The present invention relates to a light emitting device and a method for manufacturing the same, and more particularly to a light emitting device including a light emitting element and a method for manufacturing the same.

Conventionally, as a light emitting device such as a light emitting diode, a light emitting device that emits primary light and a phosphor that is excited by the primary light and emits secondary light having a wavelength different from that of the primary light There is. Another light-emitting device includes a plurality of light-emitting elements having different emission colors such as red, green, and blue.

In the manufacture of such a light-emitting device, variations in emission chromaticity occur due to variations in the emission wavelength of the light-emitting elements, variations in the particle size and content of the phosphor, and the like. A product whose emission chromaticity is not within the specified range is not usually adopted as a product.

For example, Patent Document 1 discloses that an average particle diameter of 1 to 20 μm including any one of pigment particles, particles colored with a dye, and phosphor particles on almost the entire surface of a silicone resin that seals a light emitting diode element. It is described that the color correction of the luminescent color of the light emitting diode device is performed by adhering these fine particles alone or mixed with fine particles that are not colored.

JP 2009-141051 A

However, in the light emitting diode device described in Patent Document 1, the fine particles attached to almost the entire surface of the silicone resin sealing resin include any one of pigment particles, particles colored with a dye, and phosphor particles. Otherwise, the effect of color correction of the emission color is not exhibited.

Accordingly, the present invention has been made in view of such circumstances, and a light emitting device in which emission chromaticity is corrected by a principle different from the conventional one, or light emission in which emission chromaticity can be corrected by a principle different from the conventional one. An object is to provide a method for manufacturing a device.

In order to solve the above problems, a light-emitting device of the present invention includes a visible light-emitting element, a visible light-emitting phosphor excited by light of the light-emitting element, and the light-emitting element on the phosphor. Or a translucent member including a translucent base material provided including the phosphor, and nanoparticles having a different refractive index from the base material provided on the upper surface of the translucent member are aggregated. And a coating film.

Another light-emitting device of the present invention includes a plurality of light-emitting elements having different emission colors, a light-transmitting member including a light-transmitting base material provided on the plurality of light-emitting elements, and the light-transmitting member. Provided on the top surface,
The base material includes a coating formed by agglomerating nanoparticles having different refractive indexes.

Furthermore, the manufacturing method of the light emitting device of the present invention includes a visible light emitting element, a visible light emitting phosphor excited by light of the light emitting element, and the light emitting element, on the phosphor or the A light-emitting device manufacturing method comprising a light-transmitting member including a light-transmitting base material provided including a phosphor, and having a refractive index different from that of the base material on an upper surface of the light-transmitting member. It comprises a step of forming a film formed by aggregation of nanoparticles.

According to another aspect of the present invention, there is provided a method for manufacturing a light emitting device, comprising: a plurality of light emitting elements having different emission colors; and a light transmitting member including a light transmitting base material provided on the plurality of light emitting elements. A method for manufacturing a light emitting device, comprising a step of forming a film formed by agglomerating nanoparticles having a refractive index different from that of the base material on an upper surface of the translucent member.

According to the light emitting device of the present invention, it is possible to obtain a light emitting device in which the light emission chromaticity is suitably corrected. Moreover, according to the method for manufacturing a light emitting device of the present invention, it is possible to provide a method for manufacturing a light emitting device capable of suitably correcting the light emission chromaticity.

It is the schematic top view (a) of the light-emitting device which concerns on one embodiment of this invention, and the schematic sectional drawing (b) in the AA cross section. It is the schematic (a), (b) explaining the principle of correction | amendment of the light emission chromaticity of the light-emitting device which concerns on one embodiment of this invention. It is the schematic (a), (b) explaining an example of the manufacturing method of the light-emitting device which concerns on one embodiment of this invention. It is a schematic sectional drawing of the light-emitting device which concerns on one embodiment of this invention. It is a schematic sectional drawing of the light-emitting device which concerns on one embodiment of this invention. It is the schematic top view (a) of the light-emitting device which concerns on one embodiment of this invention, and the schematic sectional drawing (b) in the BB cross section. It is the schematic top view (a) of the light-emitting device which concerns on one embodiment of this invention, and the schematic sectional drawing (b) in the CC cross section.

Hereinafter, embodiments of the invention will be described with reference to the drawings as appropriate. However, the light-emitting device and the manufacturing method thereof described below are for embodying the technical idea of the present invention, and the present invention is not limited to the following unless otherwise specified. The contents described in one embodiment and example are applicable to other embodiments and examples. In addition, the size, positional relationship, and the like of members illustrated in each drawing may be exaggerated for clarity of explanation.

<Embodiment 1>
FIG. 1A is a schematic top view of the light-emitting device according to Embodiment 1, and FIG.
It is a schematic sectional drawing which shows the AA cross section in (a). As shown in FIG.
Includes a light emitting element 10, a translucent member 20, and a coating 40. Further, the light emitting device 10
0 includes a mounting substrate 50 on which the light emitting element 10 is mounted. The mounting substrate 50 includes the enclosure 7
Contains zero. The light emitting element 10 emits visible light. The translucent member 20 includes a translucent base material 25. The translucent member 20 includes a phosphor 27 and is provided on the light emitting element 10. The phosphor 27 is a material that emits visible light and is excited by light from the light emitting element 10. The coating 40 is formed of the translucent member 2.
0 is provided on the upper surface. The coating 40 is formed by agglomerating nanoparticles 30 having a refractive index different from that of the base material 25 of the translucent member.

More specifically, the mounting substrate 50 is a package in which a pair of positive and negative lead frames are integrally held by an enclosure 70 that is a resin molded body. The light emitting element 10 includes the enclosure 70.
In the recess. The light emitting element 10 is bonded on one lead frame and connected to both lead frames by wires. The translucent member 20 is filled in the concave portion of the enclosure 70 and covers the light emitting element 10. The base material 25 of the translucent member is a cured resin.

The “nanoparticle” can be defined as a particle having a particle size of 1 nm to 100 nm, for example. The “particle size” of the particles can be defined by an average particle size or a center particle size. More specifically, the primary particle size can be measured by microscopic observation or BET method, and the secondary particle size can be measured by dynamic light scattering method, diffusion method, diffraction method or the like.

In the light emitting device 100 having such a configuration, the light emission chromaticity is suitably corrected according to the principle described below.

FIGS. 2A and 2B are schematic diagrams for explaining the principle of correction of the light emission chromaticity of the light emitting device according to the first embodiment. First, as shown in FIG. 2A, when the refractive index n ₄₀ of the coating 40 is larger than the refractive index n _{25 of the} base material 25 of the translucent member, the primary light L _{1 at} the interface between the coating 40 and the air.
The reflected light component is increased more than that at the interface between the base material 25 of the translucent member and the air. A part of the reflected light component of the primary light L ₁ that has returned into the translucent member 20 is 2 by the phosphor 27.
It is converted into the following light _{L 2.} Primary light _L long secondary light _{L 2} having a wavelength from ₁ easily transmitted through the film 40 as compared with the first-order light _{L 1.} Accordingly, the ratio of the secondary light L ₂ to the light emitted from the light emitting device 100 is relatively increased with respect to the primary light L ₁ , and the light emission chromaticity can be corrected to the long wavelength side.
On the other hand, as shown in FIG. 2B, when the refractive index n ₄₀ of the coating 40 is smaller than the refractive index n _{25 of the} base material 25 of the translucent member, the primary light L ₁ is reflected at the interface between the coating 40 and the air. The light component is reduced more than that at the interface between the base material 25 of the translucent member and the air. Thereby, the ratio of the primary light L ₁ passing through the coating 40 is increased, conversion into secondary light L ₂ is reduced due to the phosphor 27 of the primary light L _1. Therefore, light emitted from the light emitting device 100, the secondary light _{L 2} to the primary light L
The ratio of ₁ is relatively increased, and the emission chromaticity can be corrected to the short wavelength side.

In addition, since the coating film 40 is composed of the nanoparticles 30, high adhesion of the coating film 40 to the upper surface of the translucent member 20 is obtained, and reflection and scattering of light by the particles are suppressed, and high light extraction efficiency is maintained. can do.

FIGS. 3A and 3B are schematic views for explaining an example of the method for manufacturing the light emitting device according to Embodiment 1. FIG. The manufacturing method of the light-emitting device 100 includes the base material 2 of the translucent member on the upper surface of the translucent member 20.
5 is a process of forming a film 40 formed by agglomerating nanoparticles having different refractive indexes (film forming process).
It comprises. Note that the light-emitting device work-in-process 99 is in the middle of the process of manufacturing the light-emitting device 100. For example, the light-emitting element 10 is sealed (in this embodiment, the translucent member 20 on the light-emitting element 10). At the stage where the formation of the above is completed.

In the film forming step, for example, as shown in FIG. 3A, the upper surface of the translucent member 20 is immersed in a dispersion liquid 90 in which the nanoparticles 30 are dispersed in a volatile liquid or resin.
Can be formed. Thereby, the film 40 can be easily formed on the upper surface of the translucent member 20, and the light emission chromaticity of the light emitting device 100 can be corrected with high productivity. Here, the immersion in the dispersion 90 may be at least the upper surface of the translucent member 20, but the entire work-in-process item 99 of the light emitting device may be immersed in the dispersion 90 as illustrated. In addition, the light emitting device 1
When 00 includes a surrounding body 70 that surrounds the light emitting element 10 and the translucent member 20, it is preferable to immerse the surrounding body 70 in the dispersion 90. Thereby, the film 40 can also be provided on the enclosure 70.

Further, in the film forming step, for example, as shown in FIG. 3B, the dispersion liquid 90 in which the nanoparticles 30 are dispersed in a volatile liquid or resin is applied to the upper surface of the translucent member 20. 40 can be formed. Thereby, the film 40 can be formed on the upper surface of the translucent member 20 with good controllability, and the light emission chromaticity of the light emitting device 100 can be corrected with high accuracy. Specific methods for applying the dispersion 90 to the upper surface of the translucent member 20 include potting with a dispenser, spraying with an ink jet or spray, application with a brush or sponge, and the like.

When the nanoparticles 30 are dispersed in the resin, the amount of the resin is preferably an amount that does not hinder the conductivity of the conductive member (lead frame, wiring, protruding electrode, etc.). In addition, when the light emitting device 100 includes the surrounding body 70 that surrounds the light emitting element 10 and the translucent member 20, it is preferable to apply the dispersion 90 to the surrounding body 70. Thereby, the film 40 can also be provided on the enclosure 70.

The coating 40 is preferably formed after the translucent member 20 is provided on the light emitting element 10. Thereby, it is easy to adjust the light emission chromaticity as the whole light emitting device 100 (a complex of light emitting elements), and the light emission chromaticity can be easily corrected. Conversely, the coating 40 may be formed before the translucent member 20 is provided on the light emitting element 10. In this case, since the coating 40 is individually formed with respect to the translucent member 20, formation of the coating 40 in the unintended part of the light-emitting device 100 can be avoided.

Before the step of forming the coating film 40, it is preferable to include a step of measuring the chromaticity of light emitted from the translucent member 20 (preliminary emission chromaticity measurement step). Thereby, it is easy to correct the emission chromaticity of the light emitting device 100 to a desired value. Further, the content of the nanoparticles 30 of the light emitting device 100, particularly the coating film 40 and the translucent member 20, is based on the difference between the measured chromaticity (in the preliminary emission chromaticity measurement step) and the desired chromaticity. Is preferably determined. Thus, the light emitting device 10
The emission chromaticity of 0 can be corrected with high accuracy. The content of the nanoparticles 30 of the light emitting device 100 is the concentration of the dispersion 90 and / or the immersion time when immersed in the dispersion 90, such as the concentration of the dispersion 90 and / or when the dispersion 90 is applied. The number of times of application can be controlled.

  Hereinafter, a preferable embodiment of the light emitting device 100 will be described.

As shown in FIG. 1, in the light emitting device 100, the nanoparticles 30 are impregnated in the base material 25 of the translucent member. More specifically, the nanoparticles 30 are impregnated on the upper surface side in the base material 25 of the translucent member. Such a configuration includes, for example, the nanoparticle 30 from the upper surface side of the translucent member 20 to the base material 25.
It is obtained by impregnating inside. Due to the nanoparticles 30 in the base material 25 of the translucent member,
The function of correcting the emission chromaticity by the coating 40 can be supplemented. It can be considered that this is because light is scattered and / or the effective refractive index of the translucent member 20 is changed due to the presence of the nanoparticles 30.

The particle size of the nanoparticles 30 may be a particle size that allows Rayleigh scattering of light (primary light) from the light emitting device 10 (at least one of the light emitting devices when there are a plurality of light emitting devices). Specifically, the particle size of the nanoparticles 30 that can be Rayleigh scattered can be defined as a particle size that is 1/10 or less of the wavelength of light, for example. Light tends to be scattered by particles as the wavelength is shorter. That is, primary light from a light emitting element having a relatively short wavelength is easily scattered by particles,
Secondary light from a phosphor having a relatively long wavelength tends to pass through the particles. In particular, when the particle size of the nanoparticles 30 is a particle size that can be Rayleigh scattered, the tendency appears remarkably. Therefore, in this case, it is possible to selectively control such that the short wavelength light is scattered by the nanoparticles 30 and the long wavelength light passes through the nanoparticles 30. In particular, when the refractive index of the nanoparticles 30 is higher than the refractive index of the base material 25 of the translucent member, the light scattering intensity by the nanoparticles 30 can be increased. Accordingly, the correction amount of the light emission chromaticity of the light emitting device 100 can be increased.

When the refractive index of the nanoparticles 30 is larger than the refractive index of the base material 25 of the translucent member, as described above, the refractive index of the coating 40 becomes larger than the refractive index of the base material 25 of the translucent member, and the light emitting device. The emission chromaticity of 100 can be corrected to the long wavelength side. In this case, the nanoparticle 30 can use, for example, titanium oxide. Conversely, when the refractive index of the nanoparticles 30 is smaller than the refractive index of the base material 25 of the translucent member, as described above, the refractive index of the coating 40 becomes smaller than the refractive index of the base material 25 of the translucent member. The emission chromaticity of the light emitting device 100 can be corrected to the short wavelength side. Moreover, the change of the refractive index between the translucent member 20 and the air layer can be moderated, the light extraction efficiency can be increased, and the luminous flux can be increased. In this case, for example, silicon oxide can be used for the nanoparticles 30.

As shown in FIG. 1, the light emitting device 100 includes a mounting substrate 50 on which the light emitting element 10 is mounted. The mounting substrate 50 has a silver-containing film 60 on the surface. And the translucent member 20 is
A silver-containing film 60 is covered. Thus, by providing the coating film 40 on the upper surface of the translucent member 20, the corrosive gas such as the sulfur-containing gas is prevented from passing through the translucent member 20,
Discoloration of the silver-containing film 60 can be suppressed. In particular, when the nanoparticles 30 are impregnated on the upper surface side of the base material 25 of the translucent member, the gas barrier property of the translucent member 20 is improved, which is more preferable.

As shown in FIG. 1, the light emitting device 100 includes a surrounding body 70 that surrounds the periphery of the light emitting element 10 and the translucent member 20. The coating 40 is also provided on the enclosure 70. Thereby, the coating film 40 functions as a protective film of the enclosure 70, and deterioration of the enclosure 70 such as discoloration can be suppressed.

The correction amount of the light emission chromaticity of the light emitting device 100 depends on the content of the nanoparticles 30 in the coating film 40 and the light transmitting member 20, and is preferably in a substantially proportional relationship. Usually, the light emission chromaticity of the light emitting device as a product is corrected so that the difference in light emission chromaticity between the light emitting devices is reduced or eliminated. For this reason, it is preferable that the content of the nanoparticles 30 of the coating 40 and the translucent member 20 depends on the correction amount of the emission chromaticity of the light emitting device 100.

<Embodiment 2>
FIG. 4 is a schematic cross-sectional view of the light emitting device according to the second embodiment. As shown in FIG. 4, the light emitting device 200 includes a light emitting element 11, a translucent member 21, and a coating 40. Light emitting device 2
00 does not include a mounting substrate on which the light emitting element 11 is mounted. The light emitting device 200 is a so-called so-called
This is called a chip size package (CSP). The light emitting device 200 is
A surrounding body 71 surrounding the light emitting element 11 is included. The enclosure 71 is provided in contact with the side and the lower side of the light emitting element 11. In addition, the light emitting device 200 includes the protruding electrode 8 connected to the light emitting element 11.
0 is provided. The light emitting element 11 emits visible light. The translucent member 21 includes a translucent base material 25.
including. The translucent member 21 includes a phosphor 27 and is provided on the light emitting element 11. The phosphor 27 is a material that emits visible light and is excited by light from the light emitting element 11. The coating 40 is provided on the upper surface of the translucent member 21. The coating 40 is formed by agglomerating nanoparticles 30 having a refractive index different from that of the base material 25 of the translucent member.

More specifically, the light-emitting element 11 does not have a substrate and is mainly composed of a thin film having a semiconductor element structure, but may have a substrate. The light emitting element 11 has a positive and negative protruding electrode 80 connected to the lower side thereof. The surrounding body 71 is a resin molded body, and includes the light emitting element 11.
And the protruding electrode 80 are integrally covered. The upper surface of the envelope 71 is substantially the same as the upper surface of the light emitting element 11, and the lower surface is substantially the same as the lower surface of the protruding electrode 80. The translucent member 21 is
It is plate-shaped or thin-film-shaped, and covers the upper surface of the light emitting element 11 and the upper surface of the enclosure 71. The base material 25 of the translucent member is a cured resin. The side surface of the translucent member 21 and the side surface of the enclosure 71 are substantially the same surface, and the coating film 40 is also provided on this side surface.

The light emitting device 200 having such a configuration also has the light emission chromaticity suitably corrected by the coating 40. The principle of correcting the emission chromaticity is the same as that described in the first embodiment. Further, the coating 40 in the light emitting device 200 can be formed by the process described in the first embodiment.

<Embodiment 3>
FIG. 5 is a schematic cross-sectional view of the light emitting device according to the third embodiment. As shown in FIG. 5, the light emitting device 250 includes the light emitting element 12, the translucent member 21, and the coating 40. Light emitting device 2
50 does not include a mounting substrate on which the light emitting element 12 is mounted and an enclosure. Light emitting device 25
0 is also called a so-called chip size package (CSP). In addition, the light emitting device 250 includes a protruding electrode 80 connected to the light emitting element 12. The light emitting element 12 emits visible light. The translucent member 21 includes a translucent base material 25. The translucent member 21 is
The phosphor 27 is included and provided on the light emitting element 12. The phosphor 27 is a visible light emitting material that is excited by light from the light emitting element 12. The coating 40 is provided on the upper surface of the translucent member 21. The coating 40 is formed by agglomerating nanoparticles 30 having a refractive index different from that of the base material 25 of the translucent member.

More specifically, the light-emitting element 12 has a conductive substrate, and has a semiconductor element structure above it. Further, the light emitting element 12 has a protruding electrode 80 having either positive or negative polarity connected above the element structure. The translucent member 21 has a plate shape or a thin film shape and covers the upper surface of the light emitting element 12. The base material 25 of the translucent member is a cured resin. The upper surface of the translucent member 21 is
It is substantially flush with the upper surface of the protruding electrode 80. The side surfaces of the light emitting element 12 and the translucent member 21 are substantially the same surface, and the coating 40 is also provided on these side surfaces.

The light emitting device 250 having such a configuration also has a light emission chromaticity suitably corrected by the coating 40. The principle of correcting the emission chromaticity is the same as that described in the first embodiment. Further, the coating film 40 in the light emitting device 250 can be formed by the process described in the first embodiment.

As shown in FIG. 5, in the light emitting device 250, the coating 40 covers the light emitting element 12. Thereby, the coating film 40 functions as a protective film of the light emitting element 12, and deterioration of the end face of the semiconductor can be suppressed.

<Embodiment 4>
FIG. 6A is a schematic top view of the light-emitting device according to Embodiment 4, and FIG.
It is a schematic sectional drawing which shows the BB cross section in (a). As shown in FIG.
Includes a light emitting element 13, a translucent member 22, and a coating 40. The light emitting device 30
0 includes a mounting substrate 51 on which the light emitting element 13 is mounted. The light emitting element 13 emits visible light. A phosphor 28 is provided on the light emitting element 13. The translucent member 22 includes a translucent base material 25. The translucent member 22 is provided on the light emitting element 10 and the phosphor 28. The phosphor 28 is a material that emits visible light and is excited by light from the light emitting element 13. The coating 40 is provided on the upper surface of the translucent member 22. The coating 40 is formed by agglomerating nanoparticles 30 having a refractive index different from that of the base material 25 of the translucent member.

More specifically, the mounting substrate 50 is a wiring substrate having a substrate and wiring. In the light emitting element 13, positive and negative electrodes are bonded to the wiring on the upper surface of the mounting substrate 50 with a conductive adhesive. The phosphor 28 may be blended in a resin or may be impregnated with a resin. The translucent member 22 is provided on the upper surface of the mounting substrate 50 so as to cover the upper side and the side of the light emitting element 13 and the phosphor 28. The translucent member 22 includes a convex portion whose upper surface is formed as a convex surface, and a thin film portion whose upper surface extending around the convex portion is substantially flat. The base material 25 of the translucent member is a cured resin. Translucent member 22
Does not substantially contain a phosphor, but may contain a phosphor.

The light emitting device 300 having such a configuration also has the light emission chromaticity appropriately corrected by the coating 40. The principle of correcting the emission chromaticity is the same as that described in the first embodiment. Further, the coating film 40 in the light emitting device 300 can be formed by the process described in the first embodiment.

<Embodiment 5>
FIG. 7A is a schematic top view of the light emitting device according to Embodiment 5, and FIG.
It is a schematic sectional drawing which shows CC cross section in (a). As shown in FIG.
Comprises a plurality of light emitting elements 14a, 14b, 14c, a translucent member 23, and a coating 40. The light emitting device 400 includes a mounting substrate 52 on which the plurality of light emitting elements 14a, 14b, and 14c are mounted. The mounting substrate 52 includes an enclosure 72. A plurality of light emitting elements 14a,
14b and 14c have different emission colors. The translucent member 23 includes a translucent base material 25. The translucent member 23 is provided on the plurality of light emitting elements 14a, 14b, and 14c. The coating 40 is provided on the upper surface of the translucent member 23. The coating 40 is formed by agglomerating nanoparticles 30 having a refractive index different from that of the base material 25 of the translucent member.

More specifically, the mounting base 52 is a package in which three pairs of positive and negative lead frames are integrally held by an enclosure 72 that is a resin molded body. A plurality of light emitting elements 14a,
14 b and 14 c are accommodated in the recesses of the enclosure 72. Light emitting elements 14a, 14b, 1
4c is bonded to one lead frame in one set of lead frames and connected to both lead frames by wires. The translucent member 23 is filled in the concave portion of the enclosure 72 and covers the plurality of light emitting elements 14a, 14b, and 14c. The base material 25 of the translucent member is a cured resin.

The light emitting device 400 having such a configuration also has the light emission chromaticity appropriately corrected by the coating 40. Further, the film 40 in the light-emitting device 400 can be formed by the process described in Embodiment 1.

The principle of correction of emission chromaticity of the light emitting device 400 of the present embodiment can be described as follows, for example. Usually, the change in the refractive index of the light medium is larger on the short wavelength side (for example, in the visible wavelength range) than on the long wavelength side. In other words, light is more susceptible to changes in refractive index on the short wavelength side than on the long wavelength side. For this reason, the refractive index of the coating film 40 is the base material 2 of the translucent member.
When the refractive index is larger than 5, the reflected light component of the primary light at the interface between the coating 40 and the air increases more than that at the interface between the base material 25 of the light transmitting member and the air. The shorter wavelength side is larger than that. Therefore, in this case, the ratio of the long-wavelength primary light to the short-wavelength primary light in the light emitted from the light-emitting device 400 is relatively increased, and the emission chromaticity can be corrected to the long-wavelength side. . On the contrary, when the refractive index of the coating 40 is smaller than the refractive index of the base material 25 of the translucent member, the reflected light component of the primary light at the interface between the coating 40 and the air is the interface between the base material 25 of the translucent member and the air. This decrease is larger on the short wavelength side than on the long wavelength side. Therefore, in this case, the ratio of the short-wavelength primary light to the long-wavelength primary light in the light emitted from the light-emitting device 400 is relatively increased, and the emission chromaticity can be corrected to the short-wavelength side. .

In the illustrated light emitting device 400, the translucent member 23 does not substantially contain a phosphor. However, also in the light-emitting device of this embodiment, the light-transmitting member can contain a phosphor. In that case, an intermediate light-emitting device between the fifth embodiment and the first embodiment can be considered by combining the items described in each embodiment.

  Hereafter, each component in the light-emitting device of this invention and its manufacturing method is demonstrated.

(Light emitting elements 10, 11, 12, 13, 14a, 14b, 14c)
Light emitting elements include light emitting diode (LED) elements and semiconductor lasers (
A semiconductor light emitting element such as a laser diode (LD) element can be used. The top view shape of the light emitting element is preferably a quadrangle, particularly a square or a rectangle having a longitudinal / short direction, but may be other shapes. The side surface of the light emitting element may be substantially perpendicular to the upper surface, or may be inclined inward or outward. The thickness of the light emitting element is, for example, 0.02 mm or more and 1 mm or less, and is preferably 0.05 mm or more and 0.5 mm or less from the viewpoint of the strength of the light emitting element or the thickness of the light emitting device. The light emitting element may be any element provided with an element structure composed of various semiconductors and a pair of positive and negative electrodes. In particular, a nitride semiconductor (In _x Al _y Ga _1-xy N, 0 ≦ x, 0 ≦ y, x + y ≦ 1) capable of efficiently exciting the phosphor.
The light emitting element is preferable. In addition, a gallium arsenide-based or gallium phosphorus-based semiconductor light emitting element emitting green to red light may be used. In the case of a white light emitting device, the light emission wavelength of the light emitting element is preferably 400 nm or more and 530 nm or less, and 420 nm or more and 490 nm or less in consideration of the color mixing relationship with the wavelength converted light emitted from the phosphor. More preferably. The light emitting element usually has a substrate on which an element structure is provided. The substrate may be a crystal growth substrate capable of growing a semiconductor crystal constituting the element structure, or may be a bonding substrate bonded to an element structure separated from the crystal growth substrate. Examples of the base material of the substrate for crystal growth include sapphire, spinel, gallium nitride, aluminum nitride, silicon, silicon carbide, gallium arsenide, gallium phosphide, indium phosphide, zinc sulfide, zinc oxide, zinc selenide, diamond and the like. As a base material for the bonding substrate, silicon, silicon carbide, aluminum nitride,
Examples thereof include copper and copper-tungsten. However, the substrate can be omitted. In the case of a light emitting device in which a pair of positive and negative electrodes are provided on the same surface side, the mounting form may be face-up mounting in which each electrode is connected to a conductive member of a mounting base with a wire, or each electrode is conductively bonded It may be face-down (flip chip) mounting connected to the conductive member of the mounting substrate with an agent. In the case of a light emitting device having a counter electrode structure in which a pair of positive and negative electrodes are provided on opposite surfaces, the lower electrode is connected to the conductive member of the mounting substrate with a conductive adhesive, and the upper electrode is connected to the conductive member of the mounting substrate with a wire. Connected to the member. By providing a metal layer such as silver or aluminum or a dielectric reflection film on the mounting surface side of the light emitting element, light extraction efficiency can be increased. The number of light-emitting elements mounted on one light-emitting device may be one or more, and the size, shape, and emission wavelength may be arbitrarily selected. For example, red, green, and blue light emitting elements may be mounted on one light emitting device. The plurality of light emitting elements may be irregularly arranged, but a preferable light distribution can be easily obtained by arranging regularly or periodically such as a matrix or a concentric circle. Further, the plurality of light emitting elements can be connected in series or in parallel by a conductive member or a wire of the mounting substrate.

(Translucent members 20, 21, 22, 23)
The translucent member is a member that is provided on the light emitting element and transmits light from the light emitting element and / or the phosphor. The translucent member includes at least a translucent base material, and the base material may include a phosphor. The translucent member may be provided in contact with the light emitting element or may be provided apart from the light emitting element. The translucent member may be, for example, a sealing member, a plate-shaped or various lens-shaped window member.

(Base material 25)
It is preferable to use a thermosetting resin as the base material of the translucent member. In particular, when the glass transition temperature is not more than room temperature, the glass transition temperature is soft at room temperature, and the nanoparticles are easily impregnated into the translucent member.
The base material of the translucent member is an epoxy resin containing a triazine derivative epoxy resin, or a silicon-containing material composed of a soft or hard silicone resin, a hard silicone resin, an epoxy-modified silicone resin, a modified silicone resin alone or two or more kinds of compositions. It is preferable to use a resin or the like. However, other epoxy resins, silicone resins, urethane resins, and fluororesins may be used.

(Phosphor 27, 28)
The phosphor absorbs at least part of the primary light emitted from the light emitting element and emits secondary light having a wavelength different from that of the primary light. Thereby, it can be set as the light-emitting device which radiate | emits the mixed color light (for example, white type | system | group) of the primary light and secondary light of visible wavelength. The phosphor is, for example, europium,
Nitride-based phosphors and oxynitride-based phosphors mainly activated with lanthanoid elements such as cerium,
More specifically, α or β sialon type phosphors activated with europium, various alkaline earth metal nitride silicate phosphors, lanthanoid elements such as europium, alkalis mainly activated by transition metal elements such as manganese Earth metal halogen apatite phosphor, alkaline earth halosilicate phosphor, alkaline earth metal silicate phosphor, alkaline earth metal borate phosphor, alkaline earth metal aluminate phosphor, alkaline earth metal Rare earth aluminates, rare earth silicates or europium mainly activated by lanthanoid elements such as acid salts, alkaline earth metal sulfides, alkaline earth metal thiogallate, alkaline earth metal silicon nitride, germanate, cerium Examples thereof include organic substances and organic complexes mainly activated by lanthanoid elements such as. In addition to the above, a phosphor having similar performance and effects can be used. The phosphor may be unevenly distributed on the bottom surface side of the recess or the light emitting element side of the mounting substrate, or may be dispersed in the recess.

(Nanoparticle 30, coating 40)
Nanoparticles include silicon oxide (silica), aluminum oxide (alumina), aluminum nitride, magnesium oxide, antimony oxide, titanium oxide, zirconium oxide, calcium oxide, boric acid, zinc borate, cerium oxide, indium oxide, tin oxide, Aluminum hydroxide, magnesium hydroxide, barium sulfate, magnesium carbonate, barium carbonate, calcium silicate, barium titanate, diamond, talc, kaolin, mica, clay mineral, gold, silver and the like are preferable. By using a high refractive index material, the emission chromaticity can be easily shifted to a long wavelength, and titanium oxide is preferable as an example. Further, by using a low refractive index material, the emission chromaticity can be easily shifted to a short wavelength, and the luminous flux can be easily increased. For example, silicon oxide is preferable. The nanoparticles are not limited to these, and other types of materials can be used together if necessary. Examples of the shape of the nanoparticles include a spherical shape, a polyhedral shape, a needle shape, and a plate shape. If it is a needle-shaped or plate-shaped nanoparticle, it is easy to improve the gas barrier property of a translucent member.

(Mounting substrate 50, silver-containing film 60)
The mounting substrate is a member serving as a base on which the light emitting element is placed. The mounting substrate is mainly composed of a conductive member for supplying power to the light emitting element and a base material for holding the conductive member. Examples of the mounting substrate include a form of a package including a lead frame and a molded body, and a form of a wiring board including a substrate and wiring. The mounting substrate can also be produced by providing a wiring by plating after forming the molded body, or by laminating a thin plate provided with a wiring in advance. The mounting substrate may be in the form of a plate having no recess (side wall) in addition to the form having a recess (cup part). Those having recesses are likely to increase the luminous intensity toward the front of the apparatus, and those having a flat shape are easy to mount light emitting elements. Examples of the shape of the element mounting surface of the mounting substrate include a rectangular shape, a polygonal shape, a track shape (a shape in which a semicircle is attached to both sides of the rectangle), a circular shape, and an elliptical shape. In addition, the element mounting surface of the mounting substrate may be partially formed with a wide width, for example, in the vicinity of a portion where the light emitting element is mounted.

Examples of the lead frame base material include copper, iron, nickel, palladium, tungsten, chromium, aluminum, silver, gold, titanium, and alloys thereof. In particular, copper or a copper alloy is preferable from the viewpoint of heat dissipation, and iron or an iron alloy is preferable for bonding reliability with the light emitting element.
Of these, copper or iron-containing copper is preferable because of its high heat dissipation. The lead frame can be manufactured by subjecting these metal plates to processing such as pressing and etching. Further, a film of silver, nickel, palladium, platinum, tin, gold, copper, rhodium, or an alloy thereof, or an oxide of silver oxide or silver alloy may be formed on the surface of the lead frame.
In particular, the surface of the part where the light emitting element of the lead frame is joined may be coated with silver.
These coatings can be formed by plating, vapor deposition, sputtering, printing, coating, or the like.

The base material of the molded body is aliphatic polyamide resin, semi-aromatic polyamide resin, polyethylene terephthalate, polycyclohexane terephthalate, liquid crystal polymer, polycarbonate resin, syndiotactic polystyrene, polyphenylene ether, polyphenylene sulfide, polyether sulfone resin, polyether ketone. Thermosetting resins such as thermoplastic resins such as resins and polyarylate resins, polybismaleimide triazine resins, epoxy resins, silicone resins, silicone modified resins, silicone modified resins, polyimide resins, and polyurethane resins. Further, in these base materials, glass,
Silica, titanium oxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, calcium carbonate, calcium hydroxide, calcium silicate, magnesium silicate, wollastonite,
Mica, zinc oxide, barium titanate, potassium titanate, aluminum borate, aluminum oxide, zinc oxide, silicon carbide, antimony oxide, zinc stannate, zinc borate, iron oxide, chromium oxide, manganese oxide, carbon black, etc. Particles or fibers can be incorporated. In addition, the molded body can be formed of glass, ceramics, or the like. As a molding method of the molded body, insert molding, injection molding, extrusion molding, transfer molding and the like can be used.

The wiring is formed on at least the upper surface of the substrate, and may be formed on the inside, the lower surface, and the side surface of the substrate. Further, the wiring may have a land (die pad) portion to which the light emitting element is bonded, a terminal portion for external connection, a lead-out wiring portion for connecting them, and the like. Examples of the wiring material include copper, nickel, palladium, tungsten, chromium, titanium, aluminum, silver, gold, and alloys thereof. In particular, copper or a copper alloy is preferable from the viewpoint of heat dissipation. A film of silver, platinum, tin, gold, copper, rhodium, or an alloy thereof, or an oxide of silver oxide or silver alloy may be formed on the surface of the wiring. In particular, the surface of the part where the light emitting element of the wiring is joined may be covered with silver. These wirings and coatings can be formed by a cofire method, a postfire method, plating, vapor deposition, sputtering, printing, coating, or the like.

The base material of the substrate may be an electrically insulating base material or a conductive base material, and can be electrically insulated from the wiring through an insulating film or the like. As the base material of the substrate, aluminum oxide, aluminum nitride, zirconium oxide, zirconium nitride, titanium oxide,
Ceramics containing titanium nitride or a mixture thereof, metals containing copper, iron, nickel, chromium, aluminum, silver, gold, titanium or alloys thereof, epoxy resin, BT resin,
Resin such as polyimide resin or fiber reinforced resin of these (Reinforcement material is glass or alumina)
Is mentioned. A flexible substrate (flexible substrate) may be used. In order to efficiently reflect light from the light emitting element, a white pigment such as titanium oxide may be blended in the base resin.

(Enclosures 70 and 71)
The enclosure is a member that surrounds the periphery (side) of the light emitting element. The envelope includes a form of a package, a form of a covering member that directly covers the light emitting element, and a form of a frame provided on the wiring board. The envelope body can be configured using the same material as that of the above-described molded body. In particular, the enclosure is preferably made of a light-reflective resin such as a white resin.

(Projection electrode 80)
The protruding electrode is electrically connected to the electrode of the light emitting element, and is an external connection electrode for connecting to an external circuit. As the protruding electrode, for example, a so-called bump is cited.
As the protruding electrode, a single layer film of Au, Cu, Ni, Pd, Ag, or an alloy containing these metals, or a multilayer film thereof can be used. Au is preferable because it has low electrical resistance and contact resistance, but an AuSn alloy that is an inexpensive alloy with Sn may be used. In the case of a single layer structure, the protruding electrode can be formed by a wire bonder using the wire material described above. In the case of a single layer structure or a multilayer structure, the protruding electrode can also be formed by a plating process such as electrolytic plating or electroless plating.

(Dispersion 90)
The liquid in which the nanoparticles are dispersed is, for example, ethanol, isopropyl alcohol, toluene, hexane, propanol, petroleum benzine, gasoline, xylene, benzene, carbon tetrachloride, 1,1,1-trichloroethane, 1,2-dichloroethylene, trichloroethylene,
Tetrachloroethylene, dichloromethane, chloroform, methanol, ethyl ether,
Acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, methyl cellosolve, ethyl cellosolve, carbon disulfide, acetonitrile, diethylamine, nitrobenzene, tetrahydrofuran, dimethylformamide, N-methylpyrrolidone and the like are preferable. In particular, it is easy to impregnate the inside of the base material of the translucent member by using a liquid having an action of swelling the base material of the translucent member.

Examples according to the present invention will be described in detail below. Needless to say, the present invention is not limited to the following examples.

<Example 1>
The light emitting device of Example 1 has the structure of the example shown in FIG.
The LED is a side-emitting type SMD type LED of 8 mm, width 2.8 mm, and thickness 1.0 mm.

The mounting substrate has two lead frames and an enclosure of a resin molded body that integrally holds the lead frame, and is approximately 0.66 mm long, 2.2 mm wide, and a depth of 0. It is a package with a 3 mm recess. The two lead frames are made of a copper alloy with silver plating on the surface, part of which constitutes the bottom of the recess and extends out of the enclosure. The enclosure is
It is formed of a polyphthalamide resin containing titanium oxide and wollastonite.

The light-emitting element has a nitride semiconductor n-type layer, an active layer, and a p-type layer sequentially stacked on a sapphire substrate, and can emit blue light (center wavelength of about 460 nm). This is a light emitting diode chip having a substantially rectangular parallelepiped thickness of 0.1 mm. The electrode of the light emitting element is provided on the upper surface (semiconductor layer) side, and includes a bonding pad electrode and a stretched electrode extending from the pad electrode. This light emitting element is bonded to one (negative electrode side) lead frame with an adhesive, which is a translucent silicone resin, in the recess of the mounting substrate, and each pad electrode is connected to a positive and negative lead frame by a gold wire. Each is connected.

The translucent member is filled in the concave portion of the mounting base so as to cover the light emitting element and the wire. The upper surface of the translucent member is substantially flush with the upper surface of the enclosure (slightly concave due to curing shrinkage). The translucent member uses a soft silicone resin having a refractive index of 1.52 at a wavelength of 589 nm as a base material, and contains a YAG: Ce phosphor therein. The phosphor is dispersed above and around the light emitting element in the base material of the translucent member.

On the upper surface of the translucent member, the refractive index at a wavelength of 589 nm is 2.62, the center particle size is 3
A film having a film thickness of 50 nm to 1 μm formed by aggregation of 6 nm titanium oxide nanoparticles is provided. Moreover, this film is also provided on the mounting substrate. This coating is obtained by immersing the work in progress of the light-emitting device for about 10 seconds in a dispersion (nanoparticle concentration 0.1 to 0.4 wt%) in which nanoparticles are dispersed in a solvent that is toluene, and then drying. Formed.

<Example 2>
The light-emitting device of Example 2 was fabricated in the same manner as the light-emitting device of Example 1, except that the nanoparticles were silicon oxide having a refractive index of 1.46 at a wavelength of 589 nm and a center particle size of 25 nm.

<Evaluation 1>
In the light emitting device of Example 1, in the comparison before and after the film formation, the emission chromaticity shifted yellow,
It can be confirmed that the luminous flux maintenance factor is 99%. In the light emitting device of Example 2, it can be confirmed that the emission chromaticity is blue-shifted and the luminous flux maintenance factor is 101% in the comparison before and after the film formation.

<Evaluation 2>
In the test in which the light-emitting devices of Examples 1 and 2 were immersed in IPA, shaken well, washed with a solvent, and confirmed whether particles were dropped, the appearance of the light-emitting devices of Examples 1 and 2 was not changed. Since there is no change in emission chromaticity, it can be confirmed that there is almost no dropout of particles. Further, even in a test in which about 100 light emitting devices of Examples 1 and 2 were put in a container and shaken well to bring the light emitting devices into contact with each other and whether or not particles fall off due to a physical external force was confirmed. , 2 has no change in the appearance and no change in emission chromaticity, so it can be confirmed that there is almost no dropout of particles.

<Evaluation 3>
In the test for confirming the sulfidation resistance of the light emitting devices of Examples 1 and 2, it can be confirmed that there is little decrease in the luminous flux and the sulfidation resistance is effective compared to the light emitting device having no coating.

The light-emitting device according to the present invention includes a backlight light source of a liquid crystal display, various lighting fixtures, a large display, various display devices such as advertisements and destination guides, a digital video camera,
It can be used for an image reading apparatus, a projector apparatus, etc. in a facsimile, a copier, a scanner, and the like.

10, 11, 12, 13, 14a, 14b, 14c ... Light-emitting element 20, 21, 22, 23 ... Translucent member 25 ... Base material 27, 28 ... Phosphor 30 ... Nanoparticle 40 ... Coating 50, 51, 52 ... Mounting substrate 60 ... Silver-containing film 70,71,72 ... Enclosure 80 ... Projection electrode 90 ... Dispersion liquid 99 ... Light emitting device work in progress 100,200,250,300,400 ... Light emitting device

Claims (12)

A visible light emitting element;
A visible light emitting phosphor excited by light of the light emitting element;
A translucent member including a translucent base material provided on the phosphor or on the phosphor or including the phosphor;
Provided with an upper surface of the translucent member, and a film in which nanoparticles having a different refractive index from the base material are disposed,
The nanoparticles have a particle size of 1 nm to 100 nm,
The coating has a thickness of 50 nm to 1 μm,
The light emitting device has a refractive index of the nanoparticles smaller than that of the base material. A plurality of light emitting elements having different emission colors;
A translucent member including a translucent base material provided on the plurality of light emitting elements;
Provided with an upper surface of the translucent member, and a film in which nanoparticles having a different refractive index from the base material are disposed,
The nanoparticles have a particle size of 1 nm to 100 nm,
The coating has a thickness of 50 nm to 1 μm,
The light emitting device has a refractive index of the nanoparticles smaller than that of the base material.   The light emitting device according to claim 1, wherein the base material is at least one selected from an epoxy resin, a silicone resin, a hard silicone resin, an epoxy-modified silicone resin, and a modified silicone resin.   The light emitting device according to any one of claims 1 to 3, wherein the nanoparticles are titanium oxide, and the base material is a silicone resin.   The light emitting device according to any one of claims 1 to 3, wherein the nanoparticles are silicon oxide, and the base material is a silicone resin. Mounting the light emitting element on the mounting substrate;
Covering the light-emitting element with a translucent member containing a phosphor and a base material;
Nanoparticles having a particle size of 1 nm or more and 100 nm or less and a refractive index smaller than the refractive index of the base material are arranged on the surface of the translucent member, and the nanoparticles having a film thickness of 50 nm to 1 μm are aggregated. Forming a film,
The step of arranging the nanoparticles includes a step of applying a dispersion liquid in which the nanoparticles are dispersed in a solvent to the surface of the translucent member and drying the dispersant. Mounting a light emitting element provided with a phosphor on a mounting substrate;
A step of covering the phosphor and the light emitting element with a translucent member containing a base material;
A film in which nanoparticles having a particle diameter of 1 nm or more and 100 nm or less and a refractive index smaller than the refractive index of the base material are arranged on the surface of the translucent member, and the nanoparticles having a film thickness of 50 nm to 1 μm are aggregated. Forming a step,
The step of arranging the nanoparticles includes a step of applying a dispersion liquid in which the nanoparticles are dispersed in a solvent to the surface of the translucent member and drying the dispersant.   The method of manufacturing a light emitting device according to claim 6 or 7, wherein the step of arranging the nanoparticles is potting with a dispenser, spraying with an ink jet or spray, or application with a brush or a sponge.   The mounting substrate includes a package having two lead frames and an enclosure of a resin molded body that holds the lead frame, and the lead frame and the resin molded body form a recess, and the light emission The method for manufacturing a light emitting device according to claim 6, wherein the element is accommodated in the recess. The step of covering the light emitting element with the light transmissive member arranges the light transmissive member up to the upper surface of the recess,
10. The method for manufacturing a light emitting device according to claim 6, wherein the step of arranging the nanoparticles covers a surface from a surface of the translucent member to an upper surface of the recess.   The method for manufacturing a light emitting device according to claim 6, wherein in the step of covering the light emitting element with a light transmissive member, the light emitting element is provided with a phosphor.   The method for producing a light-emitting device according to claim 6, wherein the step of arranging the nanoparticles includes immersing the surface of the translucent member in a dispersion in which the nanoparticles are dispersed in a solvent. .

Images