JP2007273753A - Light emitting device and light emitting module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device and a light emitting module capable of inhibiting deterioration by light emitted from a light emitting element even if the light emitting element with a short light wavelength is used, so that the deterioration in light emission brightness is hard to occur after a long-term use. <P>SOLUTION: The light emitting device X includes the light emitting element 1 consisting of a first conductivity type layer 11, a light emitting layer 12 and a second conductivity type layer 13 formed on a substrate 10. It further includes optical members 2A and 2B joined in tight contact with a surface of at least one of the second conductivity type layer 13 and the substrate 10 via a glass joining material 22 and formed to be translucent by glass. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light emitting device having a light emitting element, and a light emitting module such as a lighting device or a display device including the light emitting device.

  As shown in FIG. 8, there is a light emitting device 9 in which a light emitting element 93 is accommodated in a space 92 formed by an insulating substrate 90 and a frame body 91 (see, for example, Patent Document 1).

  The insulating substrate 90 has a concave portion 94 for mounting the light emitting element 93, and conductor layers 95 and 96 are formed on the surface. The conductor layer 95 is electrically connected to the lower surface electrode (not shown) of the light emitting element 93 and is continuously provided from the bottom surface 94A of the recess 94 to the lower surface 90A of the insulating substrate 90. The conductor layer 96 is electrically connected to the upper surface electrode (not shown) of the light emitting element 93 through the wire 97, and is provided continuously from the upper surface 90B to the lower surface 90A of the insulating substrate 90.

  The frame body 91 has a through space 98 and is joined to the upper surface 90 </ b> B of the insulating substrate 90. In a state where the frame body 91 is bonded to the insulating substrate 90, a space 92 for mounting the light emitting element 93 is formed by the concave portion 94 of the insulating substrate 90 and the through space 98 of the frame body 91. In this space 92, a light transmitting part 99 is provided to protect the light emitting element 93. The translucent part 99 is formed by filling the space 92 with a transparent resin.

  Various elements are used as the light emitting element 93. For example, in the light emitting device 9, when white light is emitted, a light emitting diode that emits blue light is used. In this case, a wavelength conversion layer for converting blue light into yellow light is provided on the surface of the light transmitting portion 99 or the light emitting element 93, or a phosphor that emits yellow fluorescence is contained inside the light transmitting portion 99. It is done.

  On the other hand, in recent years, light emitting elements that emit shorter wavelength light (near ultraviolet light to blue light) have been developed (see, for example, Patent Document 2). It can be used when white light is emitted from the light emitting device 9.

Japanese Patent Laid-Open No. 5-175553 JP 2004-342732 A

  However, in the light emitting device 9, the light emitted from the light emitting element 93 is partially absorbed by the light transmitting portion 99 because the light transmitting portion 99 is made of resin. Therefore, the transmittance and mechanical strength of the translucent part 99 are deteriorated with time due to the energy of the absorbed light. As a result, when the light emitting device 9 is used for a long period of time, the radiant energy, radiant flux, radiant intensity, and intensity of light radiated from the light emitting device 9 due to deterioration of the transmittance and mechanical strength of the light transmitting portion 99 and Problems such as long-term reliability degradation may occur. In particular, when a light emitting element 93 that emits light having a short wavelength, such as a blue light emitting diode, is used as the light emitting device 9 that emits white light, the transmittance and mechanical strength of the light transmitting portion 99 deteriorate. In the case of using a light emitting element that emits light having a shorter wavelength, which has been developed in recent years, there is a higher possibility that the transmittance of the light transmitting portion 99 or the mechanical strength is deteriorated. Become.

  Furthermore, in the above light emitting device, in order to suppress deterioration of the transmittance and mechanical strength of the light transmitting portion 99, when transparent glass is used as the light transmitting portion 99, the transmittance and mechanical properties are increased by the light emitted from the light emitting element 93. Although deterioration of the strength is suppressed, there is a problem that cracks occur in the light-transmitting portion 99 due to volume shrinkage when curing the uncured transparent glass or a difference in thermal expansion between the light-emitting element 93 and the light-transmitting portion 99. Can occur. In particular, when the entire light-emitting element 93 is covered with transparent glass, the volume of the transparent glass is extremely large with respect to the volume of the light-emitting element 93, and thus the light-emitting element 93 is covered without generating cracks in the transparent glass. The light emitted from the light emitting element 93 is absorbed and scattered by the crack generated in the light transmitting portion 99, and the radiant energy, radiant flux, and radiant intensity of the light emitted from the light emitting device are reduced. The problem was.

  The present invention has been made in view of the above-described circumstances. Even when a light emitting element having a short wavelength of emitted light is used, the transmittance and mechanical properties of a light transmitting part due to light emitted from the light emitting element are used. In addition to suppressing deterioration in intensity, it is possible to suppress cracks that occur in the light-transmitting part that covers the light-emitting element, and even when used for a long period of time, it is difficult to cause deterioration of the radiation energy, radiation flux, radiation intensity, and long-term reliability. It is an object to provide a light-emitting device and a light-emitting module.

  According to a first aspect of the present invention, there is provided a light emitting device including a light emitting element in which a first conductive type layer, a light emitting layer, and a second conductive type layer are formed on a substrate, wherein the second conductive type is provided. One or a plurality of optical members that are bonded in close contact with a surface side of at least one of the mold layer and the substrate via a glass bonding material and that are formed of an inorganic material so as to have translucency A light-emitting device is provided.

  The optical member is preferably adhered to the light emitting element through a glass bonding material. Moreover, it is preferable that the refractive index of a glass bonding material is set smaller than the refractive index of a light emitting element, and the refractive index of an optical member is set larger than the refractive index of a glass bonding material.

  The plurality of optical members include, for example, a first optical member bonded to the substrate side and a second optical member bonded to the second conductivity type layer side.

  The light emitting device of the present invention may further include first and second external connection terminals exposed on the surfaces of the first and second optical members.

  The light emitting element includes, for example, a first element electrode provided between the first optical member and the substrate, and a second element electrode provided between the second optical member and the second conductivity type layer. And are further provided. In this case, the first and second element electrodes are conductively connected to the corresponding terminals of the first and second external connection terminals, for example, via the first and second relay conductors.

  The first and second relay conductors can be formed so as to penetrate the first and second optical members.

  The first and second external connection terminals can be formed so as to penetrate the first and second optical members. In this case, the first and second external connection terminals are conductively connected to the corresponding electrodes of the first and second element electrodes without passing through the relay conductor.

  The external connection terminal is preferably formed to have a light-transmitting property.

  The optical member contains, for example, one or more kinds of phosphors for converting the wavelength of light emitted from the light emitting element. In this case, the phosphor is preferably unevenly distributed on the outer surface portion of the optical member.

  As the light emitting element, for example, a device that emits light having at least one emission intensity peak in a wavelength range of 230 to 450 nm, for example, the first conductive type layer, the second conductive type layer, and the light emitting layer are zinc oxide-based. Those formed by the compound are used. In this case, the plurality of types of phosphors include light having a light emission intensity peak in a wavelength range of 400 to 500 nm, light having a light emission intensity peak in a wavelength range of 500 to 600 nm, and light emitted from the light emitting element, and It is preferable to include first to third phosphors that respectively convert light having an emission intensity peak in a wavelength range of 600 to 700 nm.

  According to a second aspect of the present invention, there is provided a light emitting module in which one or a plurality of light emitting devices are mounted on an insulating substrate, the light emitting device according to the first aspect of the present invention. A featured light emitting module is provided.

  The insulating substrate is mounted with a single light emitting device, for example, and has first and second connection conductors that are conductively connected to the light emitting device. The first and second connection conductors have, for example, a portion that is conductively connected to the light emitting device and a portion that is connected to external wiring.

  In the light-emitting device according to the present invention, at least one of the substrate and the second conductivity type layer in the light-emitting element is covered with an optical member formed of a light-transmitting inorganic material. Therefore, in the light emitting device of the present invention, at least one of the substrate and the second conductivity type layer in the light emitting element is protected by the optical member. Further, glass is generally a material that is less susceptible to deterioration in transmittance and mechanical strength than resin. Therefore, even when light from the light emitting element is transmitted through the optical member, even if the light from the light emitting element is absorbed by the optical member, the transmittance and mechanical properties of the optical member are caused by the radiant energy of the light. The possibility of strength degradation is very small. As a result, in the light emitting device of the present invention, there is a possibility that the element (optical member) protecting the light emitting element by the light from the light emitting element is deteriorated. Conventional light emitting device in which the light emitting element is protected by the resin (see FIG. 8) And the reduction of the radiant energy, radiant flux, and radiant intensity of the radiated light is suppressed. Thereby, the light-emitting device according to the present invention can output stable light over a long period of time.

  Further, in the light emitting module using the light emitting device according to the present invention, since the decrease in the radiation energy, the radiation flux, and the radiation intensity of the emitted light in the light emitting device is suppressed, stable driving can be performed for a long period of time.

  Furthermore, when the optical member is closely attached to the light emitting element via the glass bonding material, the possibility of gas remaining between the light emitting element and the optical member due to the presence of the glass bonding material is reduced. Therefore, compared with the case where gas remains between a light emitting element and an optical member, possibility that the light from a light emitting element will be reflected and scattered between a light emitting element and an optical member is reduced. Thereby, in the light emitting device of the present invention, light from the light emitting element can be efficiently introduced into the optical member. In particular, when the refractive index of the glass bonding material is set smaller than the refractive index of the light emitting element and smaller than the refractive index of the optical member, the interface between the light emitting element and the glass bonding material, and the glass bonding material and the optical member. Therefore, the light from the light emitting element can be more efficiently introduced into the optical member.

  Further, if the first and second external connection terminals are exposed on the surface of the optical member, there are various types of gaps between the light emitting device and the mounting substrate such as a wiring board or a circuit board on which predetermined wirings are formed. Appropriate conductive connection can be made by applying connection means. If the first and second external connection terminals are formed so as to have translucency, the light extraction efficiency resulting from light absorption and reflection at the first and second external connection terminals. Can be suppressed.

  Furthermore, if the optical member includes one or more kinds of phosphors for converting the wavelength of light emitted from the light emitting element, light having a target wavelength can be emitted from the light emitting device. . For example, as the light emitting element, for example, a light emitting element that emits light having at least one emission intensity peak in a wavelength range of 230 to 450 nm is used, while light emitted from the light emitting element is used as a plurality of types of phosphors. Is converted into light having an emission intensity peak in the wavelength range of 400 to 500 nm, light having an emission intensity peak in the wavelength range of 500 to 600 nm, and light having an emission intensity peak in the wavelength range of 600 to 700 nm. In the case where the first to third phosphors are used, white light can be emitted from the light emitting device.

  Of course, the light emitting device of the present invention can be configured to emit light other than white light depending on the type of phosphor used, for example, red light, green light, blue light, yellow, magenta, cyan, etc. Can be emitted.

  Furthermore, when the phosphor is unevenly distributed on the outer surface portion of the optical member, the thickness of the portion containing the phosphor is reduced, so that the optical path difference between the light transmitted perpendicularly and the light transmitted obliquely through this portion is reduced. Becomes smaller. As a result, since the difference in wavelength conversion amount between the vertically transmitted light and the obliquely transmitted light is reduced, a part of the light from the light emitting element is transmitted as it is, while one of the other lights is transmitted. When the wavelength of the part is converted and the mixed colors thereof are emitted, it is possible to suppress the color unevenness and to emit the same color light from the whole.

  In the light emitting device of the present invention, since the optical member is formed of glass and a glass bonding material is used as necessary, the light emitting device emits light having a short wavelength, for example, blue light or near Even when a zinc oxide-based compound semiconductor that emits ultraviolet light is used, it is possible to effectively suppress deterioration of the optical member. Thereby, even if it is a case where a short wavelength light emitting element is used, the fall of the light emission luminance in a light-emitting device can be suppressed effectively.

  In the following, first and second embodiments of the present invention will be described with reference to the drawings.

  First, a light emitting device according to a first embodiment of the present invention will be described with reference to FIGS.

  The light-emitting device X shown in FIGS. 1 and 2 includes a light-emitting element 1, first and second optical members 2A and 2B, and first and second external connection terminals 3A and 3B. It is configured to emit light from at least the outer surface of the first optical member 2A.

  The light-emitting element 1 is formed by laminating an n-type semiconductor layer 11, a light-emitting layer 12, and a p-type semiconductor layer 13 on a substrate 10, and is configured to emit light at least laterally. The light-emitting element 1 is, for example, a ZnO-based oxide semiconductor light-emitting diode, and is configured to emit light having a wavelength of 230 nm to 450 nm. Of course, as the light-emitting element 1, a device other than a ZnO-based oxide semiconductor light-emitting diode can be used. For example, a compound semiconductor such as a silicon carbide (SiC) -based compound semiconductor, a diamond-based compound semiconductor, or a boron nitride-based compound semiconductor. The type of the light-emitting element 1 to be used may be appropriately selected according to the wavelength of the light emitted from the light-emitting device X.

First and second element electrodes 14 and 15 are formed on the lower surface 10A of the substrate 10 and the upper surface 13A of the p-type semiconductor layer 13. These first and second element electrodes 14 and 15 are for applying a voltage between the n-type semiconductor layer 11, the light-emitting layer 12 and the p-type semiconductor layer 13 in order to emit light from the light-emitting layer 12. Is. The first and second element electrodes 14 and 15 are formed of a transparent material when it is necessary to transmit light, and are formed of a highly reflective material when it is necessary to reflect light. As a material for forming the first and second element electrodes 14 and 15, in the case where the first and second element electrodes 14 and 15 are formed transparently, ITO (Indium Tin Oxide) glass or zinc oxide-based material is used. A transparent conductive film, SnO ₂ , In ₂ O ₃ which is an oxide of indium (In) and tin (Sn), or the like is used. Further, when the first and second element electrodes 14 and 15 are formed with high reflectivity, metals and alloys having high reflectivity with respect to light having a wavelength of 230 nm to 450 nm, such as aluminum, rhodium, and silver. Etc. are used.

  The first and second optical members 2 </ b> A and 2 </ b> B serve to protect the light-emitting element 1, play a role of guiding light emitted from the light-emitting element 1 to the outside, and serve as light emission sources in the light-emitting device X. It also serves to increase the light emitting area. That is, the light emitted from the light emitting element 1 is efficiently incident on the first and second optical members 2 </ b> A and 2 </ b> B through the glass bonding material 22 in which the difference in refractive index from the light emitting element 1 is reduced. The light emitted from the light emitting element 1 is irregularly reflected inside the first and second optical members 2A and 2B, while the probability of extracting light to the outside is improved by increasing the light emitting area. It is efficiently radiated to the outside through the second optical members 2A and 2B. The first and second optical members 2A and 2B have through holes 20A and 20B in the center and are formed in a plate shape having translucency. The through holes 20A and 20B are filled with the first and second relay conductors 30A and 30B. The first and second relay conductors 30A and 30B are electrically connected between the first and second element electrodes 14 and 15 of the light emitting element 1 and the first and second external connection terminals 3A and 3B. For connection, the first and second optical members 2A and 2B penetrate in the thickness direction, and the end surfaces are exposed from the surfaces 21A and 21B of the first and second optical members 2A and 2B. Yes.

  The first and second optical members 2 </ b> A and 2 </ b> B are entirely formed of a light-transmitting inorganic material, and are bonded to the first and second element electrodes 14 and 15 through the glass bonding material 22. ing. These first and second optical members 2A and 2B are arranged in a parallel state facing each other. The glass bonding material 22 has translucency, and is made of, for example, a material having a refractive index smaller than that of the light emitting element 1 and smaller than that of the optical member 2.

  Here, as the light-transmitting inorganic material for forming the optical member 2, for example, quartz glass, optical glass (borosilicate glass) containing boric acid and silicic acid, crystal, sapphire, or meteorite, and the like are used. Can do. On the other hand, as the glass bonding material 22, for example, sol-gel glass, water glass, low melting point glass or the like has a high transmittance with respect to light having a wavelength of 230 nm to 450 nm, and is mineralized using a melting or hydrolysis reaction. A bonding material made of a light-transmitting inorganic material can be used.

  The first and second external connection terminals 3A and 3B are parts for conducting and connecting to the wiring of the mounting board when the light emitting device X is mounted on the mounting board such as the wiring board. The optical members 2A and 2B are formed in a strip shape extending from the central portion of the surfaces 21A and 21B to the side edges. These first and second external connection terminals 3A and 3B are electrically connected to the first and second element electrodes 14 and 15 of the light emitting element 1 through the first and second relay conductors 30A and 30B. It is connected.

  In the light emitting device X, the first and second optical members 2A and 2B formed of the light-transmitting inorganic material through the glass bonding material 22 are used to form the lower surface 10A (first surface) of the substrate 10 of the light emitting element 1. 1 element electrode 14) and the upper surface 13A (second element electrode 15) of the p-type semiconductor layer 13 are covered. Glass is generally a material that is less susceptible to deterioration in transmittance and mechanical strength than resin. Therefore, even if the light from the light emitting element 1 is transmitted through the first and second optical members 2A and 2B, the light from the light emitting element 1 is absorbed by the first and second optical members 2A and 2B. However, the possibility that the transmittance and mechanical strength of the first and second optical members 2A and 2B are deteriorated due to the radiant energy of the light is extremely small. As a result, in the light emitting device X, there is a possibility that the elements (first and second optical members 2A and 2B) that protect the light emitting element 1 by the light from the light emitting element 1 are deteriorated. Compared to the conventional light-emitting device 9 (see FIG. 8), the reduction of the radiant energy, radiant flux, and radiant intensity of the radiated light is suppressed. Thereby, the light emitting device X can output stable light over a long period of time.

  Further, by adopting a configuration in which the first and second optical members 2A and 2B are in close contact with the light emitting element 1 through the glass bonding material 22, the light emitting element 1 and the first and second optical members are disposed. The possibility that gas remains between 2A and 2B is reduced. Therefore, compared with the case where gas remains between the light emitting element 1 and the first and second optical members 2A and 2B, the light from the light emitting element 1 is emitted from the light emitting element 1 and the first and second optical members. The possibility of reflection and scattering between 2A and 2B is reduced. Thereby, in the light-emitting device X, the light from the light-emitting element 1 can be efficiently introduced into the first and second optical members 2A and 2B. In particular, when the refractive index of the glass bonding material 22 is set to be smaller than the refractive index of the light emitting element and smaller than the refractive indexes of the first and second optical members 2A and 2B, the light emitting element 1 and the glass bonding material 22 are used. The reflection loss due to the total reflection is reduced at the interface between the glass bonding material 22 and the total reflection according to Snell's law is suppressed at the interface between the glass bonding material 22 and the first and second optical members 2A and 2B. Light from the element 1 can be introduced into the optical member 2 more efficiently.

  Further, in the light emitting device X of the present invention, the glass bonding material 22 having the function of protecting the light emitting element 1 and efficiently extracting light from the inside of the light emitting element 1 is not attached so as to cover the entire light emitting element 1. Further, cracks in the glass bonding material 22 that occur when the light emitting device X is manufactured or when the light emitting device X is operated are suppressed. That is, when the manufacturing process of the light emitting device X or the light emitting device X is operated, for example, volume shrinkage of the glass bonding material 22 when sol-gel glass, water glass, low melting glass or the like is mineralized by melting or hydrolysis reaction. In addition, a crack is generated in the glass bonding material 22 due to a difference in thermal expansion coefficient between the light emitting element 1 and the glass bonding material 22. In particular, when the entire light-emitting element 1 is covered with the light-transmitting glass bonding material 22, the volume of the glass bonding material is extremely large with respect to the volume of the light-emitting element 1. As a result, cracks are easily generated in the glass bonding material 2. As a result, the light emitted from the light emitting element 1 is absorbed and scattered by the cracks generated in the glass bonding material 22, and the radiant energy, radiant flux, and radiant intensity of the light emitted from the light emitting device X are reduced. Therefore, in the light emitting device X of the present invention, the first and second optical members 2A and 2B are attached via the glass bonding material 22 provided in a part of the light emitting element 1, whereby the glass bonding material 22 is obtained. The deterioration of the transmittance and the mechanical strength of the first and second optical members 2A and 2B and the glass bonding material 22 can be suppressed, and the light emitting device can be operated normally over a long period of time.

  In addition, it is more preferable that the thickness of the glass bonding material 22 is 0.1 mm or more and 1.5 mm or less. When the thickness of the glass bonding material 22 is less than 0.1 mm, the volume shrinkage, thermal expansion, and thermal shrinkage of the glass bonding material 22 when the light emitting device X is manufactured and the light emitting device X is operated can be extremely small. The bonding strength and mechanical strength of the bonding material 22 become extremely small, and the first and second optical members against physical impacts from the outside to the first and second optical members 2A and 2B and the light emitting device X. 2A and 2B are easily peeled off from the light emitting element 1, and the light emitting device X cannot be operated normally. Further, when the thickness of the glass bonding material 22 is greater than 1.5 mm, the volume shrinkage of the glass bonding material 22 when the light emitting device X is manufactured and the light emitting device X is operated is increased, and the heat with the light emitting element 1 is increased. The stress caused by the difference in expansion coefficient increases, cracks occur in the glass bonding material 22, and the light emitting device X cannot be operated normally. Accordingly, the thickness of the lath bonding material 22 is more preferably 0.1 mm or more and 1.5 mm or less, and the light emitting element 1 and the first and second optical members 2A and 2B can be firmly bonded, and the light emitting device X The crack which arises in the glass bonding material 22 at the time of operating the manufacturing process and the light-emitting device X can be suppressed.

  Next, a light emitting module according to a second embodiment of the present invention will be described with reference to FIG.

  The light emitting module Y shown in FIG. 3 is configured to be surface-mountable, and includes a light emitting device 4 and a wiring board 5. That is, the light-emitting device 4 is the same as the light-emitting device X (see FIGS. 1 and 2) according to the first embodiment of the present invention described above, and includes the light-emitting element 40 and the optical members 41A and 41B. I have.

  The light emitting device 4 joins the first and second optical members 41 </ b> A and 41 </ b> B to the surfaces of the first and second element electrodes 42 </ b> A and 42 </ b> B of the light emitting element 40 through the glass bonding material 43. The lower surface 44A (second element electrode 42B) of the 40 substrate 44 and the upper surface 45A (first element electrode 42A) of the p-type semiconductor layer 45 are covered in close contact with the first and second optical members 41A and 41B. It is a thing.

  The first and second optical members 41 </ b> A and 41 </ b> B are made of a light-transmitting inorganic material and have a refractive index larger than that of the glass bonding material 43. On the other hand, the glass bonding material 43 has a refractive index smaller than that of the light emitting element 40. In addition, as the material for forming the first and second optical members 41A and 41B and the glass bonding material 43, the same material as the light emitting device X described above (see FIGS. 1 and 2) should be used. Can do.

  On the surfaces 46A and 46B of the first and second optical members 41A and 41B, strip-shaped first and second external connection terminals 47A and 47B extending between the side edges are provided. The first and second external connection terminals 47A and 47B are conductively connected to the first and second element electrodes 42A and 42B of the light emitting element 40 by the first and second relay conductors 48A and 48B. .

  On the other hand, the wiring board 5 is formed by forming first and second external connection conductors 51 </ b> A and 51 </ b> B on the surface of the insulating base material 50. The first and second external connection conductors 51A and 51B are mounted on the upper surface conductor portions 51Aa and 51Ba that are conductively connected to the first and second external connection terminals 47A and 47B of the light-emitting device 4 and a circuit board or the like. The lower surface conductor portions 51Ab and 51Bb that are conductively connected to the wiring of the object and the side surface conductor portions 51Ac and 51Bc that connect the upper surface conductor portions 51Aa and 51Ba and the lower surface conductor portions 51Ab and 51Bb are provided. Conductive connection between the top conductor portions 51Aa and 51Ba and the first and second external connection terminals 47A and 47B is performed using conductive bonding materials 52A and 52B such as solder and conductive resin.

  In the light emitting module Y, the light emitting device 4 similar to the light emitting device X described above (see FIGS. 1 and 2) is used. Therefore, in the light emitting module Y, the radiant energy, radiant flux, and radiant intensity of the light emitted from the light emitting device X are not easily reduced by the radiant energy of the light emitted from the light emitting element 40, and the light emitted from the light emitting element 40 is reduced. The first and second optical members 41A and 41B can be guided efficiently.

  Further, the light emitted from the light emitting element 40 is radiated directly from the inside of the light emitting element 40 to the outside and in all directions via the first and second optical members 41A and 41B. The efficiency with which light is extracted from the outside is improved, and the radiant energy, radiant flux, and radiant intensity of the light emitted from the light emitting device are also improved.

  The light-emitting device employed in the light-emitting device and the light-emitting module according to the present invention is not limited to those described with reference to FIGS. 1 to 3 and can be variously changed. For example, the light emitting device can be configured as shown in FIGS. However, in FIGS. 4-7, the same code | symbol is attached | subjected about the member or element similar to the light-emitting device X demonstrated with reference to FIG. 1 and FIG. 2, and duplication description is abbreviate | omitted.

  The light emitting devices X1 and X2 shown in FIGS. 4 and 5 are obtained by dispersing phosphors 60 and 70 in first and second optical members 6A, 6B, 7A, and 7B. The light emitting device X1 shown in FIG. 4 is obtained by dispersing the phosphor 60 over the entire first and second optical members 6A and 6B. The light emitting device X2 shown in FIG. The first and second optical members 7A and 7B are selectively dispersed on the outer surface portions.

The phosphors 60 and 70 to be included in the first and second optical members 6A, 6B, 7A, and 7B are selected according to the wavelength (color) of the light that should be emitted from the light emitting devices X1 and X2. For example, when white light is emitted from the light emitting devices X1 and X2, the phosphors 60 and 70 convert the light emitted from the light emitting element 1 into light having a light emission intensity peak in the wavelength range of 400 to 500 nm. A first phosphor to be converted, a second phosphor to be converted to light having an emission intensity peak in a wavelength range of 500 to 600 nm, and a third fluorescence to be converted to light having an emission intensity peak in a wavelength range of 600 to 700 nm The body is used. Examples of the first phosphor include (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu or BaMgAl ₁₀ O ₁₇ : Eu. Examples of the second phosphor include SrAl _2. Examples include O ₄ : Eu, ZnS: Cu, Al, or SrGa ₂ S ₄ : Eu. Examples of the third phosphor include SrCaS: Eu or La ₂ O ₂ S: Eu, LiEuW ₂ O _8. Can do.

  On the other hand, when white light is emitted from the light emitting devices X1 and X2 using the first to third phosphors, the light emitting element 1 has at least one emission intensity peak in the wavelength range of 230 to 450 nm, for example. What emits the light it has is used. Examples of such a light emitting element 1 include a ZnO-based oxide semiconductor light emitting diode.

  In addition, a light emitting element 1 that emits blue light is used, and phosphors 60 and 70 that convert blue light into yellow light, such as yttrium, aluminum, and garnet fluorescence activated by cerium (Ce), are used. A white light may be emitted from the light emitting devices X1 and X2 by using an alkaline earth metal orthosilicate phosphor activated with a body (YAG) or divalent europium (Eu).

  In the light emitting devices X1 and X2, the phosphors 60 and 70 are contained in the first and second optical members 6A, 6B, 7A, and 7B, but the substrate 10 of the light emitting element 1 is interposed via the glass bonding material 22. The first and second optical members 6A, 6B, 7A, in which the lower surface 10A (first element electrode 14) and the upper surface 13A (second element electrode 15) of the p-type semiconductor layer 13 are formed of an inorganic material. In the point covered with 7B, it is the same as that of previous light-emitting device X (refer FIG. 1 and FIG. 2). Therefore, also in the light emitting devices X1 and X2, the transmittance and mechanical strength of the first and second optical members 6A, 6B, 7A, and 7B, the glass bonding material 22, and the phosphors 60 and 70, the phosphors 60 and 70, and The deterioration of the luminous efficiency is suppressed, and the decrease in the radiant energy, radiant flux, and radiant intensity of the light radiated from the light emitting device X is suppressed even after long-term use.

  Since the light emitting device X1 shown in FIG. 4 is obtained by dispersing the phosphor 60 over the entire first and second optical members 6A and 6B, the first and second optical elements in which the phosphor 60 is dispersed are used. The members 6A and 6B can be easily formed. That is, the light emitting device X1 has an advantage that the first and second optical members 6A and 6B can be easily manufactured. On the other hand, in the light emitting device X2 shown in FIG. 5, the phosphor 70 is selectively dispersed on the outer surface portions of the first and second optical members 7A and 7B. An optical path difference becomes small between the light that travels horizontally through the members 7A and 7B and the light that travels in a direction inclined from the horizontal direction. As a result, since the difference in wavelength conversion between the light transmitted in the horizontal direction and the light transmitted obliquely becomes small, a part of the light from the light emitting element 1 is transmitted as it is, When the mixed colors are emitted by converting the wavelength, light of the same color can be emitted from the whole while suppressing color unevenness.

  Of course, the light emitting devices X1 and X2 can also be configured to emit light other than white by appropriately selecting the type of phosphors 60 and 70 to be used, and the first and second optical members 6A. , 6B, 7A, 7B, instead of dispersing the phosphors 60, 70, wavelength conversion layers containing phosphors may be provided on the outer surfaces of the first and second optical members 6A, 6B, 7A, 7B. .

  The light emitting device X3 shown in FIGS. 6 and 7 has the same basic configuration as the light emitting device X described above (see FIGS. 1 and 2), but the first and second external connection terminals 80A. , 80B is different from the light emitting device X described above (see FIGS. 1 and 2).

  The first and second external connection terminals 80A and 80B pass through the optical members 2A and 2B, and are directly conductively connected to the first and second element electrodes 14 and 15 of the light emitting element 1. Yes. That is, the first and second relay conductors 30A and 30B (see FIGS. 1 and 2) in the light emitting device X are substantially functioned as the first and second external connection terminals 80A and 80B. . However, the first and second external connection terminals 80A and 80B are partially formed in the first and second optical members 2A, 2A, and 2B in order to ensure conductive connection with wiring on a mounting board such as a wiring board. It protrudes from the surfaces 21A and 21B of 2B. Of course, the first and second external connection terminals 80A and 80B only need to be exposed from the surfaces 21A and 21B of the first and second optical members 2A and 2B, and the first and second optical members are not necessarily required. There is no need to project from the surfaces 21A and 21B of 2A and 2B.

  In the light emitting device X3, although the first and second external connection terminals 80A and 80B are different from the above light emitting device X (see FIGS. 1 and 2), the above inorganic material is interposed through the glass bonding material 22. By the first and second optical members 2A and 2B formed of the material, the lower surface 10A (first element electrode 14) of the substrate 10 of the light emitting element 1 and the upper surface 13A (second element electrode) of the p-type semiconductor layer 13 are formed. 15) is the same as the light emitting device X (see FIGS. 1 and 2) in that it is covered. Therefore, also in the light emitting device X3, deterioration of the first and second optical members 2A and 2B is suppressed, and the radiant energy, radiant flux, and radiant intensity of light emitted from the light emitting device X even after long-term use. Is suppressed from decreasing.

  Of course, also in the light-emitting device X3 shown in FIGS. 6 and 7, the first and second optical members 2A and 2B contain phosphors as in the light-emitting devices X2 and X3 shown in FIGS. May be. Further, the first and second optical members 2A and 2B are not limited to plate-like ones, and those having a surface formed as a curved surface, for example, lens-like members can also be employed.

1 is an overall perspective view showing a light emitting device according to a first embodiment of the present invention. It is a longitudinal cross-sectional view of the light-emitting device shown in FIG. It is a longitudinal cross-sectional view which shows the light emitting module which concerns on the 2nd Embodiment of this invention. It is a longitudinal cross-sectional view which shows the other example of the light-emitting device which concerns on this invention. It is a longitudinal cross-sectional view which shows the further another example of the light-emitting device which concerns on this invention. It is a whole perspective view which shows the other example of the light-emitting device based on this invention. It is a longitudinal cross-sectional view of the light-emitting device shown in FIG. It is sectional drawing which shows an example of the conventional light-emitting device.

Explanation of symbols

X, X1 to X3,4 Light-emitting device Y Light-emitting module 1,40 Light-emitting element 10 (for light-emitting element) Substrate 11 (for light-emitting element) n-type semiconductor layer (first conductivity type layer)
12 (light emitting element) light emitting layer 13 (light emitting element) p-type semiconductor layer (second conductivity type layer)
14, 15, 42A, 42B (light emitting element) electrode (element electrode)
2A, 2B, 6A, 6B, 7A, 7B, 41A, 41B Optical member 22, 43 Glass bonding material 3A, 3B, 47A, 47B, 80A, 80B (For light emitting device) External connection terminals 30A, 30B Relay conductor 48A, 48B External connection conductor (for light emitting module) 5 Wiring board (for light emitting module) 50 Insulating board (for light emitting module) 51A, 51B External connection conductor (connecting conductor)
60, 70 (optical member) phosphor

Claims (15)

  A light emitting device including a light emitting element having a first conductive type layer, a light emitting layer, and a second conductive type layer formed on a substrate, the surface of the light emitting element on the second conductive layer side, and A light-emitting device, further comprising a light-transmitting optical member made of an inorganic material and bonded to at least one of the surfaces on the substrate side through a bonding material made of an inorganic material.   The light emitting device according to claim 1, wherein a refractive index of the glass bonding material is set smaller than a refractive index of the light emitting element, and a refractive index of the optical member is set larger than a refractive index of the glass bonding material. .   The plurality of optical members include a first optical member bonded to the substrate side and a second optical member bonded to the second conductive type layer side. The light emitting device according to 1.   The light emitting device according to claim 3, further comprising first and second external connection terminals exposed on surfaces of the first and second optical members.   A first element electrode provided between the first optical member and the substrate; a second element electrode provided between the second optical member and the second conductivity type layer; The first and second element electrodes are electrically connected to corresponding terminals of the first and second external connection terminals via the first and second relay conductors. The light emitting device according to claim 4, which is connected.   The light emitting device according to claim 5, wherein the first and second relay conductors penetrate the first and second optical members.   The light emitting device according to claim 4, wherein the first and second external connection terminals pass through the first and second optical members.   The light emitting device according to claim 4, wherein the first or second external connection terminal has translucency.   The light emission according to any one of claims 1 to 8, wherein the first or second optical member contains one or more kinds of phosphors for converting the wavelength of light emitted from the light emitting element. apparatus.   The light emitting device according to claim 9, wherein the phosphor is unevenly distributed on an outer surface portion of the first or second optical member.   The light emitting element emits light having at least one emission intensity peak in a wavelength range of 230 to 450 nm, and the plurality of types of phosphors emit light emitted from the light emitting element at a wavelength of 400 to 500 nm. First to third light converted into light having an emission intensity peak in the range, light having an emission intensity peak in the wavelength range of 500 to 600 nm, and light having an emission intensity peak in the wavelength range of 600 to 700 nm, respectively. The light emitting device according to claim 9 or 10, comprising a phosphor.   The light emitting device according to any one of claims 1 to 11, wherein the first conductive type layer, the second conductive type layer, and the light emitting layer are zinc oxide compounds.   A light-emitting module in which one or a plurality of light-emitting devices are mounted on an insulating substrate, wherein the light-emitting device is the one described in any one of claims 1 to 12.   The light emitting device according to claim 13, wherein the insulating substrate is mounted with a single light emitting device, and has first and second external connection conductors that are conductively connected to the light emitting device. module. The light emitting module according to claim 14, wherein the first and second external connection conductors include a portion that is conductively connected to the light emitting device and a portion that is connected to an external wiring.

Images