JP5660157B2 - Light emitting device - Google Patents

Description

The present invention relates to a light emitting device in which a light emitting element is sealed with a translucent sealing member.

Various light-emitting devices using a light-emitting element as a light source have been proposed so far. For example, Patent Document 1
Proposed a light-emitting device in which the vicinity of a light-emitting element is covered with a glass material.

JP 2000-299503 A

However, the glass encapsulant formed by the sol-gel hydrolysis polymerization described in Patent Document 1 is formed much thicker than the thickness of the light-emitting element, and therefore cracks are generated due to shrinkage of the formation process. Such a glass film has extremely low gas barrier properties.

In the case of a light emitting device used in a severe environment, a resin material having excellent heat resistance and weather resistance is often used as a resin material. However, such resin materials having excellent heat resistance and weather resistance tend to have low gas barrier properties. In particular, in a vehicle-mounted light emitting device, when the mounting portion of the light emitting element is made of a metal reflecting member, the mounting portion turns black due to heat generated from the light emitting element and external high temperature and high humidity. The output is significantly reduced.

Therefore, an object of the present invention is to provide a light-emitting device that can maintain a high output even under severe usage environments.

The light-emitting device of the present invention includes a metal reflecting member, a light-emitting element fixed to the metal reflecting member, a glass film that covers the metal reflecting member and requires Si—N bonds, and a translucency that covers the glass film. And a resin. Moreover, it is preferable that the said light emitting element is sequentially covered with the said glass film and the said translucent resin.

Furthermore, the glass film preferably has a Si—H bond, and the thickness is 0.0
It is preferably 5 μm or more and 5 μm or less.

  Moreover, it is preferable that the said metal reflective member is comprised with the material which has silver.

Moreover, it is preferable that the said light emitting element is being fixed with the said metal reflective member and metal material.

The light-emitting device of the present invention has a glass film that requires a Si—N bond having a high gas barrier property between a metal reflecting member provided at a portion directly affected by the heat generation of the light-emitting element and the translucent resin. Therefore, even when used in a severe environment, the light reflecting function of the metal reflecting member is not deteriorated, and it is possible to emit light with high output over a long period of time.

The best mode for carrying out the present invention will be described below with reference to the drawings. However,
The embodiments described below exemplify a light emitting device for embodying the technical idea of the present invention, and the light emitting device of the present invention is not limited to the following.

Further, the present specification by no means specifies the members shown in the claims to the members of the embodiments. The dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments are not intended to limit the scope of the present invention only to the description unless otherwise specified. It is just an example. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation. Further, in the following description, the same name and reference sign indicate the same or the same members, and detailed description will be omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that a plurality of elements are constituted by the same member and the plurality of elements are shared by one member, and conversely, the function of one member is constituted by a plurality of members. It can also be realized by sharing.

Embodiments of a light emitting device according to the present invention will be described below in detail with reference to the drawings.
As shown in FIG. 1, the light-emitting device of this Embodiment has the light emitting element 11 and the metal reflective member 12 to which the light emitting element 11 is fixed electrically and mechanically, These are Si-N. The glass film 15 and the translucent resin 16 that are essential for bonding are sequentially covered.

(Light emitting element 11)
The light emitting element 11 has a plurality of electrodes (not shown) formed on the surface thereof, and each electrode is electrically connected to the pair of metal reflecting members 14 and the conductive wires 14. The light emitting element 11 used in the present embodiment has positive and negative electrodes formed on the same surface side, but the positive and negative electrodes may be formed on the corresponding surfaces. Good. Further, the positive and negative electrodes do not necessarily have to be formed one by one, and two or more each may be formed. In the case of a light emitting device including a fluorescent material, a semiconductor light emitting element capable of emitting light that excites the fluorescent material is preferable. As such a semiconductor light emitting device, ZnSe or GaN
Examples of the semiconductor include nitride semiconductors that can emit light with a short wavelength and can efficiently excite a fluorescent material (In _X Al _Y Ga _1-XY N, 0 ≦ X, 0 ≦ Y, X + Y ≦ 1) is preferable. Various emission wavelengths can be selected depending on the material of the semiconductor layer and the degree of mixed crystal. Although the light emitting element 11 of this Embodiment is being fixed to the surface of the metal reflective member 12 using the joining member (not shown), it is not limited to this, The support body 1 mentioned later
3 may be directly fixed to the surface of 3, or may be fixed via a heat sink between these fixed locations.

In the case where the glass film indispensable for Si—N bonds is formed up to the interface with the light emitting element 11 as in this embodiment mode, the light emitting element can be prevented from being deteriorated by moisture and corrosive gas. . More specifically, there are two types of deterioration of the light emitting element. First, the constituent elements of the light-emitting element are eluted by moisture, and the output may decrease. Another problem is that corrosion occurs in the electrode portion of the light emitting element due to high humidity conditions and corrosive gases such as nitrogen oxide and sulfur oxide, and Vf is deteriorated. These problems can be avoided by forming the glass film on the element surface. As a result, the light-emitting device of the present embodiment is not affected by the material of the translucent resin and the usage environment even when a GaAs-based or GaP-based light-emitting element that easily deteriorates due to moisture from the outside is used as the light-emitting element 11. Therefore, a light emitting device with high light extraction efficiency can be realized.

(Metal reflecting member 12)
The metal reflecting member 12 used in the present invention refers to a member made of a material capable of reflecting 70% or more of light from the mounted light emitting element 12. Moreover, although the metal reflective member 12 of this Embodiment has an electric polarity, it is not limited to this, The thing which does not have an electric polarity but became independent from the electroconductive member may be used. The metal reflecting member 12 may be formed on the outermost surface of another member by plating or the like. When the metal reflective film 12 is formed on the base of the conductive member, it is required to have good adhesiveness and electrical conductivity with a member used for electrical connection with the light emitting element. The specific electric resistance is preferably 300 μΩ-cm or less, more preferably 3 μΩ-cm or less. Specific examples include metals such as copper, aluminum, gold, silver, tungsten, iron, and nickel, and alloys such as iron-nickel alloys and phosphor bronze.

The metal reflecting member 12 of the present invention exists in the vicinity of the light emitting element 11. For this reason, the deterioration of the metal reflecting member greatly affects the light output and color of the light emitting device. For this reason, in this Embodiment, the glass film which makes a Si-N bond essential is provided in the interface of the metal reflective member 12 and the resin 16 mentioned later, and, thereby, the output fall of the light-emitting device resulting from discoloration of a metal reflective member , The wavelength dependency of the light reflectance is maintained, and the change in the emission color is prevented. In particular, the metal reflecting member 12 having at least the outermost surface made of silver or an alloy indispensable to silver is not suitable for a light-emitting device conventionally used under high temperature and high humidity because of its remarkable deterioration due to gas. However, by applying to the present invention, a light emitting device with high light extraction efficiency can be realized regardless of the resin material and usage environment described later.

Moreover, it is preferable that the outermost surface of the metal reflecting member 12 has irregularities in order to efficiently extract light from the light emitting element to be mounted to the outside. Further, in the case where the outermost surface of the metal reflecting member 12 has irregularities, adhesion with a glass film to be described later can be improved and shrinkage stress during the formation of the glass film 15 can be reduced. Thereby, the glass film 15 excellent in anticorrosion property with almost no cracks on the surface of the metal reflecting member 12 can be formed. Furthermore, it is preferable that the surface of the metal reflecting member 12 protrudes from the surface of an insulating support 13 described later. Thereby, when the glass film 15 is formed on the surface of the metal reflecting member 12, excess glass film forming material flows into the surface of the insulating support 13 described later, and an appropriate film is formed on the surface of the conductive member 12. A thick glass film can be formed. Thereby, the glass film 15 with few cracks on the surface of the metal reflecting member 12 can be easily formed. In this embodiment mode, a light-emitting device in which a light-emitting element is independently fixed to a conductive member is described. However, the light-emitting element is not limited to a mode in which the light-emitting element is disposed independently, and a light-receiving element, an electrostatic protection element (a Zener diode, A capacitor or the like) or a combination of at least two of them can be used as a semiconductor device. Note that the electrostatic protection element may be disposed on either the same conductive member as the light emitting element or a different conductive member in consideration of the polarity with the light emitting element.

(Support 13)
The support 13 may be made of any material as long as the metal reflecting member 12 can be held on the surface. Especially, it is preferable that it is a material which has insulation and light-shielding properties, such as a ceramic and milky white resin. Moreover, it is preferable to form from the material with a small difference of a thermal expansion coefficient with the glass film 15 so that adhesiveness can be maintained even when the glass film 15 expand | swells with the heat | fever generated from the light emitting elements 11 and 12 grade | etc.,.

(Joining member)
Here, the joining member for fixing the light emitting element 11 to the metal reflecting member 12 is preferably made of a metal material. As a result, it is possible to prevent deterioration of the bonding agent due to light irradiation or heat generation from the light emitting element and light absorption accompanying the deterioration discoloration. Specifically, Au-Sn alloy,
SnAgCu alloy, SnPb alloy, InSn alloy, Ag, SnAg can be used. As shown in FIG. 1, when a light emitting element having positive and negative electrodes on the same surface side is used and the surface on which the electrode is not formed is fixed to the conductive member, the electrode of the light emitting element is not formed. It is preferable to fix the conductive member on the surface using a metal film previously formed by sputtering, vapor deposition, plating, or the like. Thereby, it can be set as the light-emitting device excellent in heat dissipation. Specifically, a paste in which a metal material and a flux are mixed is applied onto the conductive member by dispensing, pin transfer, printing, or the like. The light emitting element in which a metal film is formed in advance is placed on the paste, and the metal material can be bonded by heating and melting by reflow. When a light-emitting element having positive and negative electrodes on the opposing surfaces is used as the light-emitting element, a single-layer film or a laminated film of a metal or alloy such as Ni, Ti, Au, Pt, Pd, or W on the surface of the electrode It is preferable to perform metal bonding to the metal reflecting member with a metal material by the same method as described above.

(Conductive wire 14)
When the electrode surfaces of the light emitting elements 11 and 12 and the conductive member are electrically connected without facing each other, the conductive wire 14 is used. The conductive wire 14 is required to have good ohmic properties, mechanical connectivity, electrical conductivity, and thermal conductivity with the electrode of the light emitting element. Specific examples of such conductive wires include conductive wires using metals such as gold, copper, platinum, and aluminum, and alloys thereof.

(Glass film 15)
The metal reflecting member 12 of the present invention is covered with a glass film 15 that has an essential Si—N bond with high gas barrier properties. Although the glass film 15 of this Embodiment is arrange | positioned so that both the metal reflective member 12 and the translucent resin 16 may be contacted, it is not limited to this, At least the metal reflective member 12 and the translucent If it exists between the resin 16, the effect of the present invention can be exhibited. Here, in this specification, the glass material which essentially requires Si-N bonds specifically refers to a material in which the converted state of perhydropolysilazane is incomplete and Si-N bonds of unreacted groups are present. It is.

Such a glass film 15 can be obtained by the following steps. First, a material obtained by diluting perhydropolysilazane in a solvent not containing water such as xylene at a concentration of about 0.1 to 10% is applied to the surfaces of the metal reflecting member 12 and the light emitting element 11 by spraying. The coating thickness is 0.05 μm after the curing treatment depending on the concentration of perhydropolysilazane and the structure of the film forming surface.
It is necessary to select appropriately so that it may become m or more and 5 micrometers or less. After the application, the solvent which has been allowed to stand at room temperature for about 5 hours is volatilized, and then heated in an atmospheric oven at 200 ° C. for 5 hours to advance the vitrification reaction. Here, in the production method for obtaining the glass film of the present invention, the first step of diluting the glass main material in an anhydrous solvent and the solution obtained in the first step are applied and the temperature is 25 ° C. or higher and 90 ° C. or lower. It has the 2nd process of volatilizing the said solvent component at temperature, and the 3rd process hardened | cured at the temperature of 100 to 300 degreeC. As a result, the glass film does not become a complete inorganic film but a protective film having flexibility against an increase in shrinkage stress that requires Si—N bonds.
Specifically, the thickness of the solvent can be reduced by having the first step, and the film having a uniform thickness can be formed by having the second step. By applying the third step after the first step and the second step, a glass film having an essential Si-N bond can be obtained.

The glass film 15 of the present invention preferably further has a Si—H bond, whereby a highly reliable light-emitting device can be obtained. The thickness of the glass film 15 of the present invention is preferably 0.05 μm or more and 5 μm or less. With this, the glass film 15 has a high gas barrier property and can efficiently extract light from the light emitting element to the outside. can do. When it is thinner than 0.05 μm, the protective effect of the light emitting element and the conductive member is insufficient, which is not preferable. If it is thicker than 5 μm, cracks will occur during production and lighting,
The gas barrier property is lost. In the case of forming a high-power light emitting device, it is preferable that the glass film has a thickness of 0.1 μm or more and 2 μm or less in consideration of the amount of heat generated from the light emitting element. Here, in this specification, the thickness of the film indicates an average value of the film thickness in the planar direction.

(Translucent resin 16)
The translucent resin 16 of the present invention is formed so as to cover the glass film 15. Translucent resin 1
6 may be formed of any resin material as long as it is translucent to the light of the light emitting element to be mounted. For example, silicone resin, polyphthalamide (PPA), polycarbonate resin, polyphenylene sulfide (PPS), liquid crystal polymer (LCP), ABS
Examples thereof include resins such as resins, epoxy resins, funol resins, acrylic resins, and PBT resins. In these materials, various dyes or pigments may be mixed and used as a colorant.
Examples thereof include Cr ₂ O ₃ , MnO ₂ , Fe ₂ O ₃ , carbon black and the like. Furthermore, the light emitting surface side of the sealing resin can have a lens effect by making it a desired shape. Specifically, a convex lens shape, a concave lens shape, an elliptical shape as viewed from the light emission observation surface, or a shape obtained by combining a plurality of them can be used. Note that in this specification, translucency means a property of transmitting about 70% or more of light emitted from a light emitting element.

The translucent resin 16 may contain a light diffusing material or a wavelength conversion member. The light diffusing material diffuses light, can reduce the directivity from the light emitting element, and can increase the viewing angle. The wavelength conversion member converts light from the light emitting element, and can convert the wavelength of light emitted from the light emitting element to the outside of the sealing member. An example of the wavelength conversion member is a fluorescent material. When the light from the light emitting element is high energy short wavelength visible light,
Perylene derivatives which are organic fluorescent substances, ZnCdS: Cu, YAG: Ce, Eu and / or
Alternatively, various inorganic fluorescent materials such as nitrogen-containing CaO—Al ₂ O ₃ —SiO ₂ activated by Cr are suitably used. In the present invention, when white light is obtained, in particular, when a YAG: Ce fluorescent material is used, light from the blue light emitting element and a yellow color which is a complementary color by partially absorbing the light can be emitted depending on the content. The system can be formed relatively easily and reliably. Similarly, Eu
When a nitrogen-containing CaO—Al ₂ O ₃ —SiO ₂ fluorescent material activated with Cr and / or Cr is used, light from the blue light-emitting element and a part of the light are absorbed depending on the content, thereby becoming a complementary color. The red color can emit light, and the white color can be formed relatively easily and reliably. In addition to these fluorescent materials, any of the known fluorescent materials described in, for example, JP-A-2005-19646, JP-A-2005-8844, and the like can be used. In the present invention, since the metal reflecting member 12 is firmly protected by the glass film, an inexpensive sulfide phosphor can be used. The sulfide phosphor includes alkaline earth, thiogallate, thiosilicate, zinc sulfide, and oxysulfide. As the alkaline earth phosphor, MS: Rn (M is M
1 or more selected from g, Ca, Sr and Ba, Re is one or more selected from Eu and Ce), etc., and MN2S4: Rn (M is Mg, Ca, S) as a thiogallate phosphor
one or more selected from r and Ba, N is one or more selected from Al, Ga, In and Y, R
e is one or more selected from Eu and Ce), and M ₂ is a thiosilicate phosphor.
LS ₄ (M is one or more selected from Mg, Ca, Ba, Sr, Ba, L is Si, Ge,
1 or more kinds selected from Sn, Re is one or more kinds selected from Eu and Ce), etc., and ZnS: K (K is one or more kinds selected from Ag, Cu and Al) as the zinc sulfide phosphor As the oxysulfide phosphor, Ln ₂ O ₂ S: Re (Ln is 1 selected from Y, La, and Gd)
More than species).

The light-emitting device of the present invention can be used for various light sources such as illumination light sources, various indicator light sources, in-vehicle light sources, display light sources, liquid crystal backlight light sources, sensor light sources, traffic lights, in-vehicle components, signboard channel letters, etc. Can be used.

FIG. 1 is a schematic cross-sectional view of a light emitting device according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of a light emitting device according to an embodiment of the present invention.

10, 20 ... light emitting device,
11 ... Light emitting element 12 ... Conductive member 13 ... Support,
14 ... conductive wire,
15 ... Glass film 16 ... Translucent resin

Claims (12)

A metal reflective member, a light emitting element fixed to said metal reflecting member, and a glass film containing, as essential Si-N bonds covering the metal reflecting member, and a translucent resin to cover the glass film possess, The light emitting device, wherein the light emitting element is fixed via a heat sink . The light emitting device according to claim 1, wherein the glass film is present at an interface between the metal reflecting member and the translucent resin. The light emitting device according to claim 1, wherein the light emitting element is sequentially covered with the glass film and the translucent resin. The light emitting device according to claim 1, wherein the glass film further has a Si—H bond. 5. The light emitting device according to claim 1, wherein the glass film has a thickness of 0.05 μm or more and 5 μm or less. The light emitting device according to claim 1, wherein the metal reflecting member is made of a material containing silver. The said metal reflecting member is hold | maintained on the surface of the support body, The surface of the said metal reflecting member protrudes from the surface of the said support body, The Claim 1 thru | or 6 characterized by the above-mentioned. The light-emitting device of description. Fixing the light emitting element to the metal reflecting member;
Forming a glass film that covers the metal reflecting member and essentially requires a Si-N bond;
Forming a translucent resin covering the glass film,
The method for manufacturing a light emitting device, wherein the light emitting element is fixed via a heat sink. 9. The method of manufacturing a light emitting device according to claim 8, wherein in the step of forming the glass film, a material diluted with perhydropolysilazane is applied to the surface of the metal reflecting member by spraying. The method for manufacturing a light-emitting device according to claim 9, wherein the perhydropolysilazane is diluted with an anhydrous solvent, and the step of forming the glass film includes a step of volatilizing the solvent and a step of curing. The method for manufacturing a light emitting device according to claim 8, wherein the glass film has a thickness of 0.05 μm or more and 5 μm or less. The metal reflective member is held on a surface of a support, and the surface of the metal reflective member protrudes from the surface of the support. The manufacturing method of the light-emitting device of description.

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