JP2008159707A - Light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light-emitting apparatus which improves heat radiation performance and prevents a visible light emitted using a phosphor having an emission peak wavelength on a low wavelength side, from being absorbed by a phosphor having an emission peak wavelength on a long wavelength side when two kinds of phosphors have different emission colors. <P>SOLUTION: The light-emitting device has: a mounting substrate 20 having an LED chip 10 mounted thereon; a sheet-like first color converting section 61 formed of a red phosphor (first phosphor) to be excited with a blue light emitted from the LED chip 10 for red light emission and a light-transmissive material; and a second color converting section 62 containing a green phosphor (second phosphor) to be excited with a blue light emitted from the LED chip 10 for green light emission. The first color converting section 61 is laminated on a light extracting surface 11 side of the LED chip 10, and the second color converting section 62 is laminated on the side opposite to the LED chip 10 side in the first color converting section 61. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a light emitting device using an LED chip (light emitting diode chip).

  Conventionally, light emission in which a desired mixed color light (for example, white light) is obtained by combining an LED chip and a phosphor that emits light of a light emission color different from that of the LED chip when excited by light emitted from the LED chip. Research and development of the apparatus is performed in various places (for example, refer to Patent Document 1).

Here, in Patent Document 1, as shown in FIG. 6, an LED chip 10 ′, a mounting substrate 20 ′ on which the LED chip 10 ′ is mounted, and a convex lens-like shape disposed on the LED chip 10 ′. Optical member (light extraction increasing portion) 140 ′, and a phosphor and a translucent material that are excited by visible light emitted from LED chip 10 ′ and emit visible light having a color different from the emission color of LED chip 10 ′ A light emitting device 1 including a dome-shaped color conversion member (wavelength conversion member) 160 ′ formed of (for example, silicone resin) and hermetically sealed to the mounting substrate 20 ′ so as to cover the optical member 140 ′. 'Has been proposed. Here, the mounting substrate 20 ′ is provided with a housing recess 20a ′ for housing a part of the LED chip 10 ′ and the optical member 140 ′ on one surface, and the LED chip 10 ′ is placed in the housing recess 20a ′. Flip chip mounting. The light emitting device 1 ′ having the configuration shown in FIG. 6 includes a sealing portion 50 ′ made of a sealing resin that seals the LED chip 10 ′ stored in the storage recess 20a ′ of the mounting substrate 20 ′. Yes.
JP 2005-158949 A

  By the way, in the light emitting device 1 ′ having the configuration shown in FIG. 6, not only the LED chip 10 ′ but also the phosphor of the color conversion member 160 ′ generates heat when turned on, but most of the color conversion member 160 ′ is in contact with air. Therefore, the heat of the color conversion member 160 ′ is hardly dissipated, and there is a concern about the thermal deterioration of the color conversion member 160 ′. In addition, when a red phosphor and a green phosphor are used as the phosphors in the color conversion member 160 ', a part of the green light emitted from the green phosphor is secondarily absorbed by the red phosphor.

  The present invention has been made in view of the above-mentioned reasons, and the object thereof is from a phosphor that can improve heat dissipation and has an emission peak wavelength on the low wavelength side of two types of phosphors having different emission colors. An object of the present invention is to provide a light emitting device capable of suppressing the emitted visible light from being absorbed by a phosphor having an emission peak wavelength on the long wavelength side.

  According to the first aspect of the present invention, an LED chip that emits visible light, a mounting board on which the LED chip is mounted, and a mounting board on the mounting surface side of the LED chip on the mounting board are disposed so as to surround the LED chip. A light emitting device comprising a provided dome-shaped optical member, and a sealing portion made of a sealing resin that seals the LED chip in a space surrounded by the optical member and the mounting substrate, and radiates from the LED chip A sheet-like first color converter formed of a first phosphor and a translucent material that is excited by visible light and emits visible light having a longer wavelength than the LED chip, and is emitted from the LED chip A second color conversion unit including a second phosphor that is excited by visible light and emits visible light having a wavelength longer than that of the LED chip and shorter than that of the first phosphor. Is the LED chip And the second color conversion unit is arranged so as not to be upstream from the first color conversion unit in the propagation direction of visible light emitted from the light extraction surface of the LED chip. It is characterized by.

  According to this invention, the sheet-like first color formed by the first phosphor and the translucent material that are excited by the visible light emitted from the LED chip and emit visible light having a longer wavelength than the LED chip. Since the conversion unit is laminated on the light extraction surface side of the LED chip, the heat generated in the first phosphor of the first color conversion unit can be dissipated to the mounting substrate side, so that heat dissipation can be improved. And the 2nd color conversion part containing the 2nd fluorescent substance which is excited by the visible light radiated | emitted from a LED chip, and radiates | emits visible light with a longer wavelength than a LED chip and a shorter wavelength than a 1st fluorescent substance Are arranged so as not to be upstream of the first color conversion unit in the propagation direction of the visible light emitted from the light extraction surface of the LED chip, the first phosphor and the second phosphor The two types of Suppressing secondary absorption of visible light emitted from the second phosphor having the emission peak wavelength on the low wavelength side among the phosphors by the first phosphor having the emission peak wavelength on the long wavelength side. Is possible.

  According to a second aspect of the present invention, in the first aspect of the invention, the second color conversion section is formed in a sheet shape from the second phosphor and a light-transmitting material, and the LED chip in the first color conversion section. It is characterized by being laminated on the side opposite to the side.

  According to the present invention, heat generated in the second phosphor of the second color conversion unit is radiated to the mounting substrate side through the LED chip, so that heat dissipation is improved.

  According to a third aspect of the present invention, in the second aspect of the present invention, the second color conversion unit has a larger planar size than the first color conversion unit.

  According to this invention, color unevenness can be suppressed compared to a case where the planar size of the second color conversion unit is equal to or smaller than the planar size of the first color conversion unit.

  According to a fourth aspect of the present invention, in the first aspect of the invention, the two-color conversion portion is formed in a sheet shape from the second phosphor and a light-transmitting material, and is parallel to the light extraction surface of the LED chip. The LED chip is stacked on the light extraction surface side of the LED chip so as to be aligned with the first color conversion unit in a plane.

  According to the present invention, heat generated in the second phosphor of the second color conversion unit is radiated to the mounting substrate side through the LED chip, so that heat dissipation is improved.

  According to a fifth aspect of the present invention, in the invention of the fourth aspect, the sealing portion is formed by dispersing a light diffusing material.

  According to this invention, the color unevenness of the mixed color light emitted from the sealing portion can be suppressed.

  According to a sixth aspect of the invention, in the first aspect of the invention, the sealing portion also serves as the second color conversion portion.

  According to this invention, the heat generated in the second phosphor can be radiated more effectively through the mounting substrate.

  According to a seventh aspect of the present invention, in the first aspect of the invention, the optical member also serves as the second color conversion unit.

  According to this invention, the heat generated in the second phosphor can be radiated more effectively through the sealing portion and the mounting substrate. Further, as compared with the case where the second fluorescent material is contained in the sealing portion as in the sixth aspect of the invention, it is possible to suppress color unevenness.

  According to an eighth aspect of the present invention, in the first aspect of the invention, the second color conversion portion is formed in a dome shape larger than the optical member, and an air layer is formed between the light emitting surface of the optical member. It is characterized by being arranged in the form.

  According to the present invention, since an air layer is formed between the second color conversion unit and the optical member, visible light emitted from the second phosphor is transferred to the first phosphor. It is possible to more reliably suppress the next absorption.

  The invention according to claim 9 is the medium according to claim 2, claim 3 or claim 5, wherein the medium containing the second phosphor has a refractive index containing the first phosphor. It is characterized by being larger than the refractive index.

  According to this invention, it is possible to suppress the light emitted from the second phosphor from entering the medium containing the first phosphor.

  According to the first aspect of the present invention, the second heat-radiating peak wavelength can be improved on the low wavelength side of the two types of phosphors of the first phosphor and the second phosphor having different emission colors. There is an effect that the visible light emitted from the phosphor can be suppressed from being absorbed by the first phosphor having the emission peak wavelength on the long wavelength side.

(Embodiment 1)
As shown in FIG. 1, the light-emitting device 1 of the present embodiment includes an LED chip 10 that emits visible light (blue light in the present embodiment), a mounting substrate 20 on which the LED chip 10 is mounted, and a mounting substrate 20. In the space surrounded by the optical member 40 and the mounting substrate 20, the dome-shaped optical member 40 is disposed between the mounting surface 20 of the LED chip 10 and the mounting substrate 20. And a sealing portion 50 made of a sealing resin that seals the chip 10, and is excited on the light extraction surface 11 side of the LED chip 10 by visible light emitted from the LED chip 10 and has a longer wavelength than the LED chip 10. A sheet-like first color conversion unit 61 formed of a first phosphor that emits visible light and a translucent material is laminated, and the first color conversion unit 62 is opposite to the LED chip 10 side. The second phosphor that is excited by visible light emitted from the LED chip 10 and emits visible light having a wavelength longer than that of the LED chip 10 and lower than that of the first phosphor, and a translucent material. The second color conversion unit 62 is stacked.

  In the light emitting device 1 of the present embodiment, a GaN blue LED chip that emits blue light is used as the LED chip 10, and the blue light emitted from the LED chip 10 is used as the first phosphor of the first color conversion unit 61. Is used as a second phosphor of the second color conversion unit 62 and is excited by the blue light emitted from the LED chip 10 to emit green light. Using the particulate green phosphor, blue light emitted from the LED chip 10 and transmitted through the first color conversion unit 61, the second color conversion unit 62, and the sealing unit 50, and the red color of the first color conversion unit 61 are used. The red light emitted from the phosphor and transmitted through the second color conversion unit 62 and the sealing unit 50 and the green light emitted from the green phosphor of the second color conversion unit 62 and transmitted through the sealing unit 50 are the optical member 40. Light incident surface 40a Will be emitted from the light emitting surface 40b of the optical member 40 is incident, it is possible to obtain a high color rendering white light.

  The LED chip 10 has an anode electrode (not shown) formed on one surface side (the lower surface side in FIG. 1) in the thickness direction and a cathode electrode (shown on the upper surface side in FIG. 1) in the other thickness direction. The other surface side is the light extraction surface 11 side. Here, the anode electrode and the cathode electrode are formed of a laminated film of a lower layer Ni film and an upper layer Au film. In the present embodiment, the LED chip 10 is one that hardly emits blue light from the side surface.

  The mounting substrate 20 includes a rectangular plate-shaped submount member 30 on which the LED chip 10 is mounted on one surface side, and a rectangular plate shape on which the submount member 30 is fixed to the central portion on the one surface side. The heat transfer plate 21 and a flexible printed wiring board having a rectangular plate shape that is fixed to one surface side (the upper surface side in FIG. 1) of the heat transfer plate 21 via, for example, a polyolefin-based fixing sheet (not shown). The wiring board 22 has a rectangular window hole 24 that exposes the submount member 30 at the center. Therefore, the heat generated in the LED chip 10 is transferred to the submount member 30 and the heat transfer plate 21 without passing through the wiring board 22.

  The heat transfer plate 21 is based on a metal plate 21a made of Cu, and a coating film 21b made of an Au film is formed on both surfaces in the thickness direction of the metal plate 21a.

  On the other hand, the wiring substrate 22 is provided with a pair of wiring patterns 23 and 23 for feeding power to the LED chip 10 on one surface side of an insulating base material 22a made of a polyimide film. A resist layer 26 made of a white resin covering a portion where the wiring patterns 23, 23 are not formed in the conductive base material 22a is laminated. Here, in the LED chip 10, the cathode electrode is electrically connected to one wiring pattern 23 via the bonding wire 14, and the anode electrode is connected to the other via the electrode pattern 31 of the submount member 30 and the bonding wire 14. The wiring pattern 23 is electrically connected. Each of the wiring patterns 23 and 23 is formed in an outer peripheral shape slightly smaller than half of the outer peripheral shape of the insulating base material 22a. Further, FR4, FR5, paper phenol or the like may be employed as the material of the insulating base material 22a.

  The resist layer 26 is patterned so that two portions of each wiring pattern 23, 23 are exposed in the vicinity of the window hole 24 of the wiring substrate 22 and one portion of each wiring pattern 23, 23 is exposed in the peripheral portion of the wiring substrate 22. In each wiring pattern 23, 23, a portion exposed in the vicinity of the window hole 24 of the wiring substrate 22 constitutes a terminal portion 23 a to which the bonding wire 14 is connected, and a circle exposed at the peripheral portion of the wiring substrate 22. The part of the shape constitutes an electrode part 23b for external connection. In addition, the wiring patterns 23 and 23 of the wiring board 22 are comprised by the laminated film of Cu film | membrane, Ni film | membrane, and Au film | membrane, and the uppermost layer is Au film | membrane.

  The submount member 30 is made of AlN having a relatively high thermal conductivity and electrical insulation, and has a planar size larger than the chip size of the LED chip 10. A stress relieving function that relieves stress acting on the LED chip 10 due to a difference in linear expansion coefficient with the LED chip 10, and heat generated in the LED chip 10 in a range wider than the chip size of the LED chip 10 in the heat transfer plate 21 It has a heat conduction function to transfer heat to the. Therefore, in the light emitting device 1 of the present embodiment, the stress acting on the LED chip 10 due to the difference in linear expansion coefficient between the LED chip 10 and the heat transfer plate 21 can be relieved, and the heat generated in the LED chip 10 can be reduced. Can be efficiently radiated through the submount member 30 and the heat transfer plate 21.

  In the present embodiment, AlN having a relatively high thermal conductivity and insulating properties is adopted as the material of the submount member 30, but the material of the submount member 30 is not limited to AlN, for example, composite SiC, Si Etc. may be adopted. In addition, on the one surface side of the submount member 30, the above-described electrode pattern 31 to be bonded to the anode electrode that is an electrode on the submount member 30 side of the LED chip 10 is formed, and visible around the electrode pattern 31 A reflective film 32 that reflects light is formed. Therefore, the visible light emitted from the LED chip 10 can be prevented from being absorbed by the submount member 30, and the light extraction efficiency to the outside can be further increased. Here, the electrode pattern 31 is formed of an alloy of Au and Sn containing Au as a main component (for example, 80Au-20Sn, 70Au-30Sn, etc.). The reflective film 32 is made of Al, but is not limited to Al, and may be made of Ag, Ni, Au, or the like.

  In the light emitting device 1 of the present embodiment, the thickness dimension of the submount member 30 is set so that the surface of the submount member 30 is farther from the heat transfer plate 21 than the surface of the resist layer 26 of the wiring board 22. In addition, visible light emitted from the LED chip 10, the red phosphor, and the green phosphor can be prevented from being absorbed by the wiring substrate 22 through the inner peripheral surface of the window hole 24 of the wiring substrate 22.

  As the sealing resin that is the material of the sealing portion 50 described above, a silicone resin is used. However, the sealing resin is not limited to a silicone resin, and for example, an epoxy resin may be used.

  The optical member 40 is a molded product of a translucent material (for example, silicone resin) and is formed in a dome shape. Here, in this embodiment, since the optical member 40 is formed of silicone resin, the difference in refractive index and the linear expansion coefficient between the optical member 40 and the sealing portion 50 can be reduced. In addition, when the material of the sealing part 50 is an epoxy resin, it is preferable that the optical member 40 is also formed of an epoxy resin.

  The first color conversion unit 61 is a molded product of a mixture in which a translucent material such as a silicone resin and a particulate red phosphor that emits red light when excited by the blue light emitted from the LED chip 10 are mixed. Although it is laminated | stacked by adhering to the light extraction surface 11 side of the LED chip 10 with adhesives (for example, silicone resin, an epoxy resin, etc.), it is not necessary to use an adhesive agent. In contrast, the second color conversion unit 62 mixes a translucent material such as silicone resin and a particulate green phosphor that emits green light when excited by the blue light emitted from the LED chip 10. It is composed of a molded product of the above mixture, and is laminated by being fixed to the side opposite to the LED chip 10 side in the first color conversion unit 61 by an adhesive (for example, silicone resin, epoxy resin, etc.) It is not always necessary to use an adhesive. In addition, the translucent material used as the material of the first color conversion unit 61 and the second color conversion unit 62 is not limited to a silicone resin. Organic / inorganic hybrid materials mixed and bound together in the above may be employed. In addition, a cutout portion that exposes a connection portion between the cathode electrode of the LED chip 10 and the bonding wire 14 is formed in the peripheral portions of the first color conversion unit 61 and the second color conversion unit 62.

  In the light emitting device 1 of the present embodiment described above, a sheet-like first color conversion unit formed of a red phosphor and a translucent material that is excited by blue light emitted from the LED chip 10 and emits red light. Since 61 is laminated on the light extraction surface 11 side of the LED chip 10, heat generated in the red phosphor of the first color conversion unit 61 can be radiated to the mounting substrate 20 side through the LED chip 10. The second color conversion unit 62 containing a green phosphor that can improve heat dissipation and emit green light when excited by the blue light emitted from the LED chip 10 is emitted from the light extraction surface 11 of the LED chip 10. In the propagation direction of the blue light to be transmitted, it is arranged so as not to be upstream from the first color conversion unit 61 (in this embodiment, the first color change in the propagation direction). The green light emitted from the green phosphor having the emission peak wavelength on the low wavelength side of the two types of phosphors of the red phosphor and the green phosphor is a long wavelength. Secondary absorption by the red phosphor having the emission peak wavelength on the side can be suppressed. Here, in the light emitting device 1 of the present embodiment, the second color conversion unit 62 is formed in a sheet shape using a green phosphor and a light-transmitting material, and the first color conversion unit 61 is on the side opposite to the LED chip 10 side. Since the heat generated in the green phosphor of the second color conversion unit 62 is radiated to the mounting substrate 20 side through the LED chip 10, the heat dissipation is improved. Further, in the light emitting device 1 of the present embodiment, the light emitting surface 40b of the optical member 40 is configured by a part of a spherical surface, and the lens unit configured by the optical member 40 and the sealing unit 50 has a hemispherical shape. Therefore, it can be used as a point light source.

  By the way, in the light emitting device 1 of the present embodiment, the plane size of the first color conversion unit 61 and the plane size of the second color conversion unit 62 are set to be the same, but the plane size of the second color conversion unit 62 is set to be the same. If the plane size of the first color conversion unit 61 is made larger than that of the first color conversion unit 61, the color unevenness can be suppressed compared to the case where the plane size of the second color conversion unit 62 is equal to or smaller than the plane size of the first color conversion unit 61. .

  In the light emitting device 1 of the present embodiment, since the second color conversion unit 62 is stacked on the first color conversion unit 61, a plurality of types of second colors having different concentrations of the second phosphor in advance are manufactured. Before preparing the conversion unit 62 and stacking the second color conversion unit 62 on the first color conversion unit 61, the mixed color light emitted through the first color conversion unit 61 is detected and the detection result is determined according to the detection result. If the second color conversion unit 62 having an appropriate density is stacked on the first color conversion unit 61, color variations among the light emitting devices 1 can be reduced. In contrast, the second color conversion unit 62 and the first color conversion unit 61 may be integrally formed. In this case, the second color conversion unit 62 is stacked on the first color conversion unit 61. There is an advantage that a process is not required and manufacturing is facilitated.

  Further, in the light emitting device 1 of the present embodiment, the refractive index of the translucent material (medium) containing the green phosphor in the second color conversion unit 62 includes the red phosphor in the first color conversion unit 61. The translucent material (silicone resin in this embodiment) of each of the first color conversion unit 61 and the second color conversion unit 62 is selected so that the refractive index of the translucent material (medium) is larger. For example, the light emitted from the green phosphor of the second color conversion unit 62 can be prevented from entering the first color conversion unit 61.

(Embodiment 2)
The basic configuration of the light emitting device 1 of the present embodiment is substantially the same as that of the first embodiment, and as shown in FIG. 2, the first color conversion unit 61 and the second color conversion unit 62 are light extraction surfaces of the LED chip 10. 11 are different from each other in a plane parallel to the surface 11. Here, the second color conversion unit 62 is laminated by adhering to the light extraction surface 11 side of the LED chip 10 with an adhesive (for example, a silicone resin, an epoxy resin, or the like). There is no. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted.

  Thus, in the light emitting device 1 of the present embodiment, the blue light emitted from the LED chip 10 and transmitted through the first color conversion unit 61 and the sealing unit 50 and the first phosphor of the first color conversion unit 61 are used. The red light emitted from the red phosphor and transmitted through the sealing portion 50 and the green light emitted from the green phosphor that is the second phosphor of the second color conversion portion 61 and transmitted through the sealing portion 50 are optical members. The light is incident on the light incident surface 40a of 40 and is emitted from the light emitting surface 40b of the optical member 40, and white light with high color rendering can be obtained. Here, in the light emitting device 1 of the present embodiment, the first color conversion unit 61 and the second color conversion unit 62 are arranged side by side in a plane parallel to the light extraction surface 11 of the LED chip 10, thereby providing the second color. The conversion unit 62 is arranged so as not to be upstream of the first color conversion unit 61 in the propagation direction of the blue light emitted from the light extraction surface 11 of the LED chip 10, and the red phosphor and the green phosphor Of the green phosphors having the emission peak wavelength on the lower wavelength side among the two types of phosphors of the above are suppressed from being secondarily absorbed by the red phosphor having the emission peak wavelength on the longer wavelength side. It becomes possible. Further, in the light emitting device 1 of the present embodiment, heat generated by the green phosphor of the second color conversion unit 62 is radiated to the mounting substrate 20 side through the LED chip 10 without passing through the first color conversion unit 61. Therefore, heat dissipation improves compared with Embodiment 1.

  In the light emitting device 1 of the present embodiment, the first color conversion unit 61 and the second color conversion unit 62 are arranged in parallel in a plane parallel to the light extraction surface 11 of the LED chip 10 as described above. By adopting a configuration in which the light diffusing material is dispersed in the sealing portion 50, the color unevenness of the mixed color light emitted from the sealing portion 50 can be suppressed. As a material of the light diffusing material, for example, transparent glass having a refractive index different from that of the sealing resin that is the material of the sealing portion 50, or a metal such as Au or Ag may be employed.

(Embodiment 3)
The basic configuration of the light emitting device 1 of the present embodiment is substantially the same as that of the first embodiment. As shown in FIG. 3, the sealing unit 50 has a longer wavelength than the blue light emitted from the LED chip 10 and red fluorescence. A particulate green phosphor (second phosphor) 51 that emits green light having a shorter wavelength than the red light emitted from the body (first phosphor) is dispersed, and the sealing portion 50 is the first The difference is that it also serves as the two-color converter 62. In short, the sealing portion 50 in the present embodiment is formed by curing the sealing resin in which the green phosphor 51 is dispersed. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted.

  Therefore, in the light emitting device 1 of the present embodiment, the blue light emitted from the LED chip 10, the red light emitted from the red phosphor of the first color conversion unit 61, and the sealing unit 50 as the second color conversion unit 62. Since it is possible to obtain mixed color light with green light emitted from the green phosphor 51, it is possible to obtain white light with high color rendering, and by dispersing the green phosphor 51 in the sealing portion 50. The second color conversion unit 62 is disposed so as not to be upstream of the first color conversion unit 61 in the propagation direction of the blue light emitted from the light extraction surface 11 of the LED chip 10 (in the present embodiment). The heat generated in the green phosphor 51 can be dissipated more effectively through the mounting substrate 20, disposed downstream of the first color conversion unit 61 in the propagation direction. Further, in the light emitting device 1 of the present embodiment, the refractive index of the sealing resin (medium) containing the green phosphor in the sealing unit 50 is the transparent color containing the red phosphor in the first color conversion unit 61. If the sealing resin and the light-transmitting material are selected so as to be larger than the refractive index of the light-sensitive material (medium), the light emitted from the green phosphor of the sealing portion 50 is contained in the first color conversion portion 61. It can suppress entering into.

(Embodiment 4)
The basic configuration of the light emitting device 1 of the present embodiment shown in FIG. 4 is substantially the same as that of the first embodiment, and the optical member 40 has a longer wavelength than the blue light emitted from the LED chip 10 and the first color conversion unit 61. It is different in that it is formed of a particulate green phosphor that emits green light having a shorter wavelength than the red light emitted from the red phosphor and a translucent material, and also serves as the second color conversion unit 62. Here, the optical member 40 in the present embodiment is configured by a molded product of a mixture of a translucent material such as silicone and a green phosphor (in short, the optical member 40 is a particulate green fluorescent material). The body is dispersed). In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted.

  In the light emitting device 1 of the present embodiment, the blue light emitted from the LED chip 10, the red light emitted from the red phosphor that is the first phosphor of the color conversion layer 60, and the second light of the optical member 40. Since mixed color light with green light emitted from the green phosphor, which is a phosphor, can be obtained, white light with high color rendering can be obtained.

  Here, in the light emitting device 1 of the present embodiment, the second color conversion unit 62 is not upstream of the first color conversion unit 61 in the propagation direction of the blue light emitted from the light extraction surface 11 of the LED chip 10. (In this embodiment, it is arranged downstream of the first color conversion unit 61 in the propagation direction), and the emission peak wavelength of the red phosphor and the green phosphor with different emission colors is low. The light emitted from the green phosphor on the wavelength side can be suppressed from being secondarily absorbed by the red phosphor having the emission peak wavelength on the long wavelength side, and the light extraction efficiency can be improved. As compared with the case where the green phosphor 51 is dispersed in the sealing portion 50 as in the light emitting device 1 according to the third embodiment shown in FIG. 3, the color unevenness can be suppressed.

(Embodiment 5)
The basic configuration of the light emitting device 1 of the present embodiment is substantially the same as that of the first embodiment. As shown in FIG. 5, the color conversion unit 62 is formed in a dome shape larger than the optical member 40, and The difference is that an air layer 80 is formed between the light emitting surface and the light emitting surface. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted.

  Here, in the second color conversion unit 62 in the present embodiment, the inner surface 62 a is formed in a shape along the light emitting surface 40 b of the optical member 40. Therefore, the distance between the light emitting surface 40b in the normal direction and the inner surface 62a of the second color conversion unit 62 is a substantially constant value regardless of the position of the light emitting surface 40b of the optical member 40. Note that the second color conversion unit 62 is shaped so that the thickness along the normal direction of the outer surface 62b is uniform regardless of the position. In addition, the second color conversion unit 62 may fix the end edge (periphery of the opening) on the mounting substrate 20 side to the mounting substrate 20 by using, for example, an adhesive (for example, silicone resin, epoxy resin). Good.

  Thus, in the light emitting device 1 of the present embodiment, the second color conversion unit 62 is not upstream of the first color conversion unit 61 in the propagation direction of the blue light emitted from the light extraction surface 11 of the LED chip 10. (In this embodiment, the air layer 80 is disposed downstream of the first color conversion unit 61 in the propagation direction) and between the second color conversion unit 62 and the optical member 40. Since it is formed, it is possible to more reliably suppress the secondary absorption of the green light emitted from the green phosphor of the second color conversion unit 62 into the red phosphor of the first color conversion unit 61. Become.

1 is a schematic cross-sectional view of a light emitting device according to Embodiment 1. FIG. 6 is a schematic cross-sectional view of a light emitting device according to Embodiment 2. FIG. 6 is a schematic cross-sectional view of a light emitting device according to Embodiment 3. FIG. 6 is a schematic cross-sectional view of a light emitting device according to Embodiment 4. FIG. 6 is a schematic cross-sectional view of a light emitting device according to Embodiment 5. FIG. It is a schematic sectional drawing of the light-emitting device of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light-emitting device 10 LED chip 11 Light extraction surface 20 Mounting board 40 Optical member 50 Sealing part 61 1st color conversion part 62 2nd color conversion part 80 Air layer

Claims (9)

  An LED chip that emits visible light, a mounting substrate on which the LED chip is mounted, and a dome-shaped optical device that is disposed between the mounting substrate and the mounting substrate on the mounting surface side of the LED chip. A light emitting device comprising a member and a sealing portion made of a sealing resin that seals the LED chip in a space surrounded by the optical member and the mounting substrate, and is excited by visible light emitted from the LED chip A sheet-like first color conversion section formed of a first phosphor that emits visible light having a wavelength longer than that of the LED chip and a translucent material, and an LED excited by visible light emitted from the LED chip. A second color conversion unit containing a second phosphor that emits visible light having a longer wavelength than the chip and a shorter wavelength than the first phosphor, and the first color conversion unit is light of the LED chip. Extraction side A light-emitting device that is stacked and arranged so that the second color conversion unit is not upstream of the first color conversion unit in the propagation direction of visible light emitted from the light extraction surface of the LED chip .   The second color conversion unit is formed in a sheet shape from the second phosphor and a translucent material, and is stacked on the opposite side of the first color conversion unit from the LED chip side. The light-emitting device according to claim 1.   The light emitting device according to claim 2, wherein the second color conversion unit has a larger planar size than the first color conversion unit.   The two-color conversion unit is formed in a sheet shape from the second phosphor and a light-transmitting material, and is aligned with the first color conversion unit in a plane parallel to the light extraction surface of the LED chip. The light emitting device according to claim 1, wherein the light emitting device is laminated on the light extraction surface side of the LED chip.   The light emitting device according to claim 4, wherein the sealing portion is formed by dispersing a light diffusing material.   The light emitting device according to claim 1, wherein the sealing portion also serves as the second color conversion portion.   The light-emitting device according to claim 1, wherein the optical member also serves as the second color conversion unit.   The second color conversion unit is formed in a dome shape larger than the optical member, and is disposed in such a manner that an air layer is formed between the second color conversion unit and the light emitting surface of the optical member. Item 2. The light emitting device according to Item 1.   The refractive index of the medium containing the second phosphor is larger than the refractive index of the medium containing the first phosphor. The light-emitting device of description.

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