JP2019066680A - Wavelength conversion member and light source module - Google Patents

Abstract

To provide a wavelength conversion member having a light reflection unit that has excellent durability and can favorably reflect primary light, and secondary light and a light source module.SOLUTION: A wavelength conversion member (20) includes a wavelength conversion unit (21) for performing wavelength conversion of primary light of a prescribed wavelength to emit secondary light and a light reflection unit (22) that is disposed adjacent to the wavelength conversion unit (21) to reflect the primary light and secondary light. The light reflection unit (22) is constituted by a composite ceramics sintering body of a SiOphase (23) and a TiOphase (24).SELECTED DRAWING: Figure 2

Description

  The present invention relates to a wavelength conversion member and a light source module.

  A light emitting device is used which obtains white light by wavelength conversion with a wavelength conversion member containing a phosphor material, using an LED (Light Emitting Diode) or a semiconductor laser as a light source. In these light emitting devices, primary light such as blue light or ultraviolet light is emitted from the light source and irradiated to the wavelength conversion member, and the phosphor contained in the wavelength conversion member is excited by the primary light to generate secondary light such as yellow light Light is emitted, and the primary light and the secondary light are mixed to emit white light to the outside.

  Patent Document 1 proposes a vehicular lamp using a semiconductor laser as a light source. When a semiconductor laser is used as a light source, primary light having a large output and a narrow wavelength width can be obtained, but the directivity is very strong and the region irradiated with the light is small. Therefore, compared with the case where an LED is used as a light source, a very small area of the wavelength conversion member is irradiated with a large output primary light to emit white light, and a light emitting device having high directivity can be obtained.

  Patent Document 2 includes an optical member in which a light diffuse reflection member is adjacent to the periphery of a wavelength conversion member, and primary light from a semiconductor laser is irradiated to the wavelength conversion member, and a secondary directed from the side surface of the wavelength conversion member to the outside An optical semiconductor light emitting device is described that reflects light at a light diffuse reflector. In this prior art, among the primary light irradiated to the wavelength conversion member and scattered and the wavelength-converted secondary light, light traveling from the side to the outside is returned to the direction of the wavelength conversion member again, so the utilization efficiency of the primary light And the directivity of secondary light can be further enhanced.

  FIG. 7 is a cross-sectional view schematically showing the structure of a conventional optical member, and FIG. 7 (a) shows an example using a resin as a light diffusion reflection member, and FIG. 7 (b) shows ceramics as a light diffusion reflection member. Shows an example using. As shown in FIGS. 7A and 7B, the conventional optical member includes the wavelength conversion member 1 and the light diffusion reflection member 2, and the light diffusion reflection member 2 is disposed adjacent to the periphery of the wavelength conversion member 1. doing. In the example shown to Fig.7 (a), the light-scattering particle 4 of high refractive index is disperse | distributed in the resin 3 of the low refractive index as the light diffusive reflection member 2. As shown in FIG. In the example shown in FIG. 7B, the ceramic material 5 is used as the light diffusive reflection member 2, and polycrystalline grain boundaries and air bubbles 6 are included in the ceramic material 5. In these conventional techniques, the primary light and the secondary light are scattered and reflected by the difference in refractive index between the resin 3 and the light scattering particle 4 and the difference in refractive index between the ceramic material 5 and the bubble 6.

JP, 2012-221633, A JP, 2015-0223215, A

  However, in the prior art using the resin 3 shown in FIG. 7A, the degradation of the resin 3 due to the irradiation of the primary light which is the light of short wavelength and the heat accompanying the wavelength conversion in the wavelength conversion member 1 Deterioration of the resin 3 caused by the above-mentioned problem is a problem, and it is difficult to improve the durability of the resin 3. Further, in the prior art using ceramic material 5 shown in FIG. 7 (b), the density of the sintered body of ceramic material 5 is high, and the density of air bubbles 6 contained in ceramic material 5 is low. There are fewer interfaces that can scatter light, and it is difficult to improve the reflectance.

  Then, this invention makes it a subject to provide the wavelength conversion member provided with the light reflection part which can reflect primary light and secondary light favorably while being excellent in durability, and a light source module.

In order to solve the above-mentioned subject, the wavelength conversion member of the present invention is arranged adjacent to the wavelength conversion part which carries out wavelength conversion of the primary light of a predetermined wavelength, and emits secondary light, and is arranged A light reflecting portion for reflecting light and the secondary light is provided, and the light reflecting portion is made of a ceramic sintered body in which SiO ₂ and TiO ₂ are compounded.

In such a wavelength conversion member of the present invention, since the light reflection portion disposed adjacent to the wavelength conversion portion is made of a ceramic sintered body in which SiO ₂ and TiO ₂ are complexed, the durability is excellent. The primary light and the secondary light can be well reflected.

In one aspect of the present invention, the light reflecting portion contains TiO _{2 in a} range of 20 to 80% by volume.

In one aspect of the present invention, of the SiO ₂ or the TiO ₂ , the average particle diameter of the material having a small volume% in the light reflecting portion is 10 μm or less.

  In one aspect of the present invention, the entire side surface of the wavelength conversion member is in contact with the light reflecting portion.

  In order to solve the above-mentioned subject, a light source module of the present invention is characterized by including the wavelength conversion member according to any one of the above, and a semiconductor light emitting element for irradiating the wavelength conversion member with the primary light. I assume.

  According to the present invention, it is possible to provide a wavelength conversion member and a light source module provided with a light reflection portion which is excellent in durability and which can reflect primary light and secondary light well.

It is a schematic cross section which shows the light source module 10 in 1st Embodiment. It is a partial expanded sectional view which shows the structure of the wavelength conversion member 20 in 1st Embodiment typically. It is a schematic cross section which shows the light source module 30 in 2nd Embodiment. It is a schematic cross section which shows the light source module 40 in 3rd Embodiment. It is a schematic cross section which shows the light source module 50 in 4th Embodiment. It is a partial expanded sectional view which shows the structure of the wavelength conversion member 60 in 5th Embodiment typically. It is sectional drawing which shows the structure of the conventional optical member typically, FIG. 7 (a) shows the example using resin as a light diffusive reflection member, FIG.7 (b) uses ceramics as a light diffusive reflection member An example is shown.

First Embodiment
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or equivalent components, members, and processes shown in the drawings are denoted by the same reference numerals, and duplicative descriptions will be omitted as appropriate. FIG. 1 is a schematic cross-sectional view showing a light source module 10 in the present embodiment.

  The light source module 10 includes a stem 11, a light emitting element 12, a side wall 13, a top surface 14, and a wavelength conversion member 20. In the light source module 10, primary light is emitted from the light emitting element 12 to the wavelength conversion member 20 as indicated by arrows in the drawing, and mixed with secondary light wavelength-converted by the wavelength conversion member 20, and white light is indicated by arrows in the drawing. It is emitted outside as shown. Although FIG. 1 shows a so-called CAN type package as the light source module 10, the present invention is not limited to the CAN type package and packages for various semiconductor lasers can be used.

  The stem 11 is a member on which the light emitting element 12 is mounted and the side wall 13 is fixed. The stem 11 includes lead pins and a heat sink (not shown), and power is supplied to the light emitting element 12 from the outside. Communicate the heat to the outside. Although the material which comprises the stem 11 is not specifically limited, Metals, such as copper with favorable heat dissipation, are desirable.

  The light emitting element 12 is a semiconductor laser which is supplied with power and oscillates a laser beam. The material constituting the light emitting element 12 is not particularly limited, but when irradiating blue light or ultraviolet light as primary light, a nitride-based semiconductor is used, and the resonator structure or electrode structure of the light emitting element 12 or current narrowing The element structure such as the structure is also not particularly limited, and an appropriate structure can be adopted to obtain the required emission intensity and oscillation wavelength. In the present embodiment, a semiconductor laser is used as the light emitting element 12 for emitting primary light, but the element is not limited to the semiconductor laser as long as the element emits primary light wavelength-converted by the wavelength conversion member 20. Or organic EL.

  The side wall 13 is a cylindrical member provided upright on the stem 11 and is disposed on the stem 11 so as to surround the light emitting element 12. The top surface 14 is a flat member disposed on the side wall 13 so as to cover the light emitting element 12, and an opening is provided at the center to fix the wavelength conversion member 20. Although the material which comprises the side wall 13 and the top surface 14 is not limited, In order to transmit the heat which generate | occur | produced in the wavelength conversion member 20 favorably to the stem 11, the metal material excellent in thermal conductivity is preferable.

  FIG. 2 is a partially enlarged cross-sectional view schematically showing the structure of the wavelength conversion member 20 in the present embodiment. As shown in FIG. 2, the wavelength conversion member 20 is a sintered body in which the wavelength conversion portion 21 and the light reflection portion 22 are in contact with each other and integrally formed. The wavelength conversion member 20 is fixed to the opening of the side wall 13 and functions as a light extraction portion from the light source module 10.

  The wavelength conversion unit 21 is a portion containing a phosphor material that emits secondary light by being excited by primary light emitted from the light emitting element 12, and the white light is mixed with the primary light and the secondary light to the outside. Irradiate. Here, an example is shown in which white light is irradiated by mixing the primary light and the secondary light, but a plurality of phosphor materials are provided to emit secondary light of a plurality of colors and the white light is mixed by mixing the secondary lights. It may be irradiated. Also, although an example of white light has been shown as the light to be irradiated, other monochromatic light may be used, and a color other than white in which a plurality of colors are mixed may be used.

The size of the wavelength conversion unit 21 is larger than the area irradiated with the primary light from the light emitting element 12 as long as the wavelength of the primary light can be appropriately converted to the secondary light. It is about 1 to several mm. The phosphor material contained in the wavelength conversion portion 21 is preferably a ceramic phosphor so as to be co-sintered with the light reflection portion 22. As a specific material, a ceramic phosphor obtained by sintering a ceramic base made of Y ₃ Al ₅ O ₁₂ , that is, YAG (Yttrium Alminum Garnet) powder, is most preferable. By using a YAG sintered body as the wavelength conversion unit 21, the blue light of primary light is wavelength-converted to emit yellow light of secondary light, and white color can be obtained by mixing the primary light and the secondary light.

  In the present embodiment, an example of a sintered body formed integrally with the light reflecting portion 22 as the wavelength conversion portion 21 is shown, but the light reflecting portion 22 may be separately formed and combined, and the phosphor in the resin It may be a structure in which particles are dispersed.

The light reflecting portion 22 is a member that holds the wavelength converting portion 21 in contact with the entire side surface around the wavelength converting portion 21 and is made of a ceramic sintered body in which SiO ₂ and TiO ₂ are complexed. The light reflecting portion 22 is preferably formed integrally with the wavelength conversion portion 21 and sintered simultaneously, but may be formed separately and combined with the wavelength conversion portion 21.

As shown in FIG. 2, the light reflecting portion 22 has a structure in which the TiO ₂ phase 24 is three-dimensionally intertwined in the SiO ₂ phase 23. The SiO ₂ phase 23 is a phase in contact with the wavelength conversion portion 21 and continuously formed over the entire area of the light reflection portion 22, and the TiO ₂ phase 24 is entangled three-dimensionally inside. In Figure 2, but showing the internal TiO ₂ phase 24 is entangled three-dimensionally by the structure of the SiO ₂ phase 23, SiO ₂ phase 23 inside the TiO ₂ phase 24 is a three-dimensionally entangled structure It is also good.

The refractive index of the SiO ₂ phase 23 contained in the light reflecting portion 22 is about 1.4, and the refractive index of the TiO ₂ phase 24 is about 2.5 to 2.7, so the SiO ₂ phase 23 and the TiO ₂ phase are included. The refractive index difference of 24 is about 1.1 to 1.3. Thus, when the refractive index difference between the SiO ₂ phase 23 and the TiO ₂ phase 24 is increased, light traveling from the wavelength conversion portion 21 toward the light reflection portion 22 is three-dimensionally as shown by the arrows in FIG. The light is reflected at the interface between the entangled SiO ₂ phase 23 and the TiO ₂ phase 24. As a result, the light reflecting portion 22 as a whole becomes a white region, and light leakage in the lateral direction can be prevented, and the light is returned to the direction of the wavelength conversion portion 21 and extracted from the wavelength conversion portion 21 to the outside.

The ratio of TiO ₂ phase 24 included in the light reflecting portion 22 is preferably 20 to 80 vol% range. If the ratio of the TiO ₂ phase 24 is less than 20% by volume or exceeds 80% by volume, the composition of the SiO ₂ phase 23 and the TiO ₂ phase 24 becomes insufficient, and the area of the interface having a difference in refractive index decreases. It becomes difficult to obtain sufficient reflectance. Also, of the SiO ₂ phase 23 or TiO ₂ phase 24 included in the light reflecting portion 22, it is preferable that the average particle diameter on a volume percent of the smaller material occupying in the light reflecting portion 22 is 10μm or less. When the average particle diameter is larger than 10 μm, it is difficult to obtain a sufficient reflectance because the area of the interface having the refractive index difference is reduced.

In the present embodiment, since the light reflecting portion 22 is formed of a ceramic sintered body in which the SiO ₂ phase 23 and the TiO ₂ phase 24 are composited, the SiO ₂ phase 23 and the TiO ₂ phase 24 are entangled three-dimensionally. By the above structure, the area of the interface between the SiO ₂ phase 23 and the TiO ₂ phase 24 becomes large, and the primary light and the secondary light can be well reflected. Further, since the light reflecting portion 22 is a ceramic sintered body, it is possible to improve the resistance to heat and light as compared with the prior art using a resin and a light scattering agent.

Second Embodiment
Next, a second embodiment of the present invention will be described with reference to FIG. The same contents as the first embodiment will not be described. FIG. 3 is a schematic cross-sectional view showing the light source module 30 in the present embodiment.

  The light source module 30 includes a stem 11, a light emitting element 12, and a wavelength conversion member 20. In the light source module 30, primary light is emitted from the light emitting element 12 to the wavelength conversion member 20, mixed with secondary light wavelength-converted by the wavelength conversion member 20, and white light is emitted to the outside.

Also in this embodiment, the wavelength conversion member 20 has the wavelength conversion portion 21 and the light reflection portion 22 in contact with each other, and the light reflection portion 22 is a ceramic sintered body in which the SiO ₂ phase 23 and the TiO ₂ phase 24 are composited. It is configured. Although FIG. 2 shows an example in which the side surface of the wavelength conversion unit 21 is in contact with the light reflection unit 22 and the bottom surface is in contact with the stem 11, a recess is formed in the light reflection unit 22 and the wavelength conversion unit 21 is embedded in the recess. It may be a structure.

  The light emitting element 12 is disposed on the exposed surface side of the wavelength conversion unit 21 and emits primary light toward the wavelength conversion unit 21. The primary light incident on the wavelength conversion unit 21 is wavelength-converted by the phosphor material and is extracted from the exposed surface to the outside.

Also in this embodiment, since the light reflecting portion 22 is formed of the ceramic sintered body in which the SiO ₂ phase 23 and the TiO ₂ phase 24 are composited, the SiO ₂ phase 23 and the TiO ₂ phase 24 are entangled three-dimensionally. By the above structure, the area of the interface between the SiO ₂ phase 23 and the TiO ₂ phase 24 becomes large, and the primary light and the secondary light can be well reflected. Further, since the light reflecting portion 22 is a ceramic sintered body, it is possible to improve the resistance to heat and light as compared with the prior art using a resin and a light scattering agent.

Third Embodiment
Next, a third embodiment of the present invention will be described with reference to FIG. The same contents as the first embodiment will not be described. FIG. 4 is a schematic cross-sectional view showing the light source module 40 in the present embodiment.

  The light source module 40 of the present embodiment includes a stem 11, a light emitting element 12, and a wavelength conversion member 20, and uses an LED that emits surface light as the light emitting element 12. In the light source module 40, the plurality of light emitting elements 12 are mounted on the stem 11, the wavelength conversion member 20 is disposed above the light emitting element 12, and the wavelength conversion unit 21 covers the light emitting position of the light emitting element 12. It is done. Air gaps 41 are provided on side surfaces of the plurality of light emitting elements 12. In such a light source module 40, primary light is emitted from the light emitting element 12 to the wavelength conversion member 20, mixed with secondary light wavelength-converted by the wavelength conversion member 20, and white light is emitted to the outside.

Also in this embodiment, since the light reflecting portion 22 is formed of the ceramic sintered body in which the SiO ₂ phase 23 and the TiO ₂ phase 24 are composited, the SiO ₂ phase 23 and the TiO ₂ phase 24 are entangled three-dimensionally. By the above structure, the area of the interface between the SiO ₂ phase 23 and the TiO ₂ phase 24 becomes large, and the primary light and the secondary light can be well reflected. Further, since the light reflecting portion 22 is a ceramic sintered body, it is possible to improve the resistance to heat and light as compared with the prior art using a resin and a light scattering agent.

Fourth Embodiment
Next, a fourth embodiment of the present invention will be described with reference to FIG. The contents overlapping with the third embodiment will not be described. FIG. 5 is a schematic cross-sectional view showing the light source module 50 in the present embodiment.

  The light source module 50 according to the present embodiment includes the stem 11, the light emitting element 12, and the wavelength conversion member 20, and uses an LED that emits surface light as the light emitting element 12. In the light source module 50, the plurality of light emitting elements 12 are mounted on the stem 11, the wavelength converting member 20 is disposed above the light emitting element 12, and the wavelength converting unit 21 covers the light emitting position of the light emitting element 12. It is done. The side surfaces of the plurality of light emitting elements 12 are filled with a reflective resin 51. In the light source module 50, primary light is emitted from the light emitting element 12 to the wavelength conversion member 20, mixed with secondary light wavelength-converted by the wavelength conversion member 20, and white light is emitted to the outside.

The reflective resin 51 is a member that disperses light scattering particles in a resin material and reflects light due to the difference in refractive index between the resin and the light scattering particles. The resin material which comprises the reflection resin 51 is not limited, For example, an epoxy resin and a silicone resin can be used. The material constituting the light-scattering particles is not limited, for example _{TiO 2, Al 2 O 3,} SiO 2, ZrO 2 and the like.

  In the present embodiment, since the side surface of the light emitting element 12 is filled with the reflecting resin 51, the primary light emitted from the side surface of the light emitting element 12 is reflected by the reflecting resin 51 and returns toward the light emitting element 12. The light is extracted from the upper surface side of the light source and enters the wavelength conversion unit 21. As a result, the primary light emitted from the light emitting element 12 can efficiently reach the wavelength conversion unit 21 and can be wavelength-converted into secondary light.

Also in this embodiment, since the light reflecting portion 22 is formed of a ceramic sintered body in which the SiO ₂ phase 23 and the TiO ₂ phase 24 are composited, the SiO ₂ phase 23 and the TiO ₂ phase 24 are three-dimensionally The entangled structure makes the area of the interface between the SiO ₂ phase 23 and the TiO ₂ phase 24 large, so that the primary light and the secondary light can be well reflected. Further, since the light reflecting portion 22 is a ceramic sintered body, it is possible to improve the resistance to heat and light as compared with the prior art using a resin and a light scattering agent.

Fifth Embodiment
Next, a fifth embodiment of the present invention will be described using FIG. The same contents as the first embodiment will not be described. FIG. 6 is a partially enlarged cross-sectional view schematically showing the structure of the wavelength conversion member 60 in the present embodiment. As shown in FIG. 6, the wavelength conversion member 60 of the present embodiment is a sintered body in which the wavelength conversion portion 61 and the light reflection portion 62 are in contact with each other and integrally formed.

  The wavelength conversion unit 61 is a portion containing a phosphor material that emits secondary light by being excited by primary light emitted from the light emitting element 12, and the white light is mixed with the primary light and the secondary light to the outside. Irradiate. In the present embodiment, an example of a sintered body formed integrally with the light reflecting portion 62 as the wavelength conversion portion 61 is shown, but the light reflecting portion 62 may be separately formed and combined, and the phosphor in the resin It may be a structure in which particles are dispersed.

The light reflecting portion 62 is a member that contacts the entire side surface around the wavelength converting portion 61 and holds the wavelength converting portion 61, and is made of a ceramic sintered body. The light reflecting portion 62 is preferably formed integrally with the wavelength conversion portion 61 and sintered simultaneously, but may be formed separately and combined with the wavelength conversion portion 61. The ceramic material constituting the light reflecting portion 62 is not limited, but preferably the light absorbing end is 400 nm or less and does not absorb visible light, for example, TiO ₂ , Al ₂ O ₃ , SiO ₂ , ZrO ₂ , Y ₂ O ₃ , YAG, etc.

  As shown in FIG. 6, the light reflecting portion 62 includes a large number of closed pores 64 in the ceramic phase 63. Since the closed pore 64 is a bubble not containing a ceramic material, the refractive index is low, and the refractive index difference with the ceramic phase 63 is large. Therefore, light incident on the light reflecting portion 62 is well scattered and reflected at the interface between the ceramic phase 63 and the closed pores 64, and the light reflecting portion 22 becomes a white region as a whole. As a result, the light reflection portion 62 can prevent light leakage in the lateral direction, and the light is returned to the direction of the wavelength conversion portion 21 and extracted from the wavelength conversion portion 21 to the outside.

  Moreover, it is preferable that the ratio of the closed pore 64 in the light reflection part 22 is the range of 10-50 volume%. If the closed pores 64 are less than 10% by volume, it is difficult to increase the reflectance because the area of the interface between the ceramic phase 63 and the closed pores 64 is small. In addition, when the closed pores 64 are more than 50% by volume, it is difficult to maintain the mechanical strength of the light reflecting portion 22.

  In the present embodiment, as the light reflecting portion 22, a ceramic phase 63 in which the absorption edge of light is 400 nm or less includes 10 to 50% by volume of closed pores 64. As a result, the area of the interface between the ceramic phase 63 and the closed pores 64 is increased, and the primary light and the secondary light can be well reflected. Further, since the light reflecting portion 22 is a ceramic sintered body, it is possible to improve the resistance to heat and light as compared with the prior art using a resin and a light scattering agent.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10, 30, 40, 50 ... Light source module 11 ... Stem 12 ... Light emitting element 13 ... Side wall 14 ... Top surface 20, 60 ... Wavelength conversion member 21, 61 ... Wavelength conversion part 22, 62 ... Light reflection part 23 ... SiO ₂ phase 24 TiO ₂ phase 41 void 51 reflective resin 63 ceramic phase 64 closed pore

Claims (5)

A wavelength conversion unit that wavelength-converts primary light of a predetermined wavelength and emits secondary light;
A light reflection unit disposed adjacent to the wavelength conversion unit and reflecting the primary light and the secondary light;
The light reflecting portion, the wavelength conversion member, characterized in that it is composed of SiO ₂ and TiO ₂ in ceramics sintered body composite. A wavelength conversion member according to claim 1, wherein
The wavelength conversion member characterized in that TiO ₂ is contained in a range of 20 to 80% by volume in the light reflecting portion. The wavelength conversion member according to claim 1 or 2,
A wavelength conversion member characterized in that an average particle diameter of a material having a small volume percentage occupied in the light reflecting portion among the SiO ₂ or the TiO ₂ is 10 μm or less. A wavelength conversion member according to any one of claims 1 to 3, wherein
A wavelength conversion member, wherein the entire side surface of the wavelength conversion member is in contact with the light reflecting portion. A wavelength conversion member according to any one of claims 1 to 4;
A light source module comprising a semiconductor light emitting element for emitting the primary light to the wavelength conversion member.