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US-12625301-B2 - Wavelength conversion module

US12625301B2US 12625301 B2US12625301 B2US 12625301B2US-12625301-B2

Abstract

A wavelength conversion module includes a base, a wavelength conversion member consisting of a phosphor, and a bonding member including a metal part that bonds the base and the wavelength conversion member. A thickness of the wavelength conversion member is less than 100 μm.

Inventors

  • Teppei Kunimune
  • Yasuaki KAWATA

Assignees

  • NICHIA CORPORATION

Dates

Publication Date
20260512
Application Date
20220720
Priority Date
20210721

Claims (19)

  1. 1 . A wavelength conversion module comprising: a base; a wavelength conversion member consisting of a phosphor; and a bonding member including a metal part, the bonding member bonding the base and the wavelength conversion member, wherein a thickness of the wavelength conversion member is less than 95 μm, wherein the wavelength conversion member is formed of a polycrystalline body, and the metal part of the bonding member is a metal sintered compact having a porous structure defining voids.
  2. 2 . The wavelength conversion module according to claim 1 , wherein the bonding member further includes a resin part.
  3. 3 . The wavelength conversion module according to claim 2 , wherein the resin part includes a first resin portion covering an outer surface of the metal sintered compact, and second resin portions impregnated in the voids, the first resin portion and the second resin portions being made of the same resin material.
  4. 4 . The wavelength conversion module according to claim 3 , wherein the first resin portion is located at a side surface of the wavelength conversion member.
  5. 5 . The wavelength conversion module according to claim 1 , further comprising a protective film disposed on the wavelength conversion member.
  6. 6 . The wavelength conversion module according to claim 5 , wherein an outermost surface of the protective film is formed of an oxide.
  7. 7 . The wavelength conversion module according to claim 5 , wherein the bonding member further includes a resin part disposed at an outer peripheral portion of the outermost surface of the protective film.
  8. 8 . The wavelength conversion module according to claim 1 , further comprising a bonding layer disposed under the wavelength conversion member between the wavelength conversion member and the bonding member.
  9. 9 . The wavelength conversion module according to claim 1 , wherein the phosphor is a rare earth aluminate sintered compact having a composition represented by Formula (I), ( Ln 1 - n ⁢ Ce n ) 3 ⁢ ( Al 1 - m ⁢ M m 1 ) 5 ⁢ O 12 ( I ) wherein, Ln is at least one rare earth element selected from the group consisting of Y, La, Lu, Gd, and Tb, M 1 is at least one element selected from Ga and Sc, and m and n are numbers satisfying 0≤m≤0.02 and 0.0017≤n≤0.0170 respectively.
  10. 10 . The wavelength conversion module according to claim 9 , wherein a Ce content (mol %) of the phosphor is calculated by n×3×100/(3+5+12), and is in a range from 0.025 mol % to 0.255 mol %.
  11. 11 . A wavelength conversion module comprising: a base; a wavelength conversion member consisting of a phosphor; a bonding member including a metal part, the bonding member bonding the base and the wavelength conversion member; and a protective film disposed on the wavelength conversion member, wherein a thickness of the wavelength conversion member is less than 100 μm, and the bonding member further includes a resin part disposed at an outer peripheral portion of the outermost surface of the protective film.
  12. 12 . The wavelength conversion module according to claim 11 , wherein the wavelength conversion member is formed of a polycrystalline body.
  13. 13 . The wavelength conversion module according to claim 11 , wherein the metal part of the bonding member is a metal sintered compact having a porous structure defining voids.
  14. 14 . The wavelength conversion module according to claim 13 , wherein: the resin part includes a first resin portion covering an outer surface of the metal sintered compact, and second resin portions impregnated in the voids, the first resin portion and the second resin portions being made of the same resin material.
  15. 15 . The wavelength conversion module according to claim 14 , wherein the first resin portion is located at a side surface of the wavelength conversion member.
  16. 16 . The wavelength conversion module according to claim 11 , wherein an outermost surface of the protective film is formed of an oxide.
  17. 17 . The wavelength conversion module according to claim 11 , further comprising a bonding layer disposed under the wavelength conversion member between the wavelength conversion member and the bonding member.
  18. 18 . The wavelength conversion module according to claim 11 , wherein the phosphor is a rare earth aluminate sintered compact having a composition represented by Formula (1), ( Ln 1 - n ⁢ Ce n ) 3 ⁢ ( Al 1 - m ⁢ M m 1 ) 5 ⁢ O 12 ( I ) wherein, Ln is at least one rare earth element selected from the group consisting of Y, La, Lu, Gd, and Tb, M1 is at least one element selected from Ga and Sc, and m and n are numbers satisfying 0≤m≤0.02 and 0.0017≤n≤0.0170 respectively.
  19. 19 . The wavelength conversion module according to claim 18 , wherein a Ce content (mol %) of the phosphor is calculated by n×3×100/(3+5+12), and is in a range from 0.025 mol % to 0.255 mol %.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to Japanese Patent Application No. 2021-120944 filed on Jul. 21, 2021, the disclosure of which is hereby incorporated herein by reference in its entirety. BACKGROUND The present disclosure relates to a wavelength conversion module. In recent years, as a light source for headlights, various illumination devices, laser projectors, etc., for example, a light source having a high output such that blue light from a semiconductor laser is wavelength-converted by a phosphor have been widely used. In this light source, a phosphor generates heat in accordance with the wavelength conversion, so it has been required to efficiently exhaust the heat generated in the phosphor. In particular, in a wavelength conversion device used in the light source using the semiconductor laser, it has been required to use a wavelength conversion member having good durability and to efficiently exhaust the heat generated in the wavelength conversion member. In response to these requirements, Japanese Patent Application Publication No. 2019-207761 discloses a wavelength conversion device (also referred to as a wavelength conversion module) in which a ceramic phosphor is used as a wavelength conversion member, and the ceramic phosphor is bonded to a heat dissipation member by a bonding member having a sintered structure. According to the above publication, a high thermal conductivity can be obtained by using the bonding member having the sintered structure including at least one of silver, gold, and copper. SUMMARY A higher output light source is required, and a wavelength conversion module having a wavelength conversion member used for such a light source is also required to have higher reliability. Therefore, an object of the present disclosure is to provide a highly reliable wavelength conversion module. A wavelength conversion module according to the present disclosure includes a base, a wavelength conversion member consisting of a phosphor, and a bonding member including a metal part, the bonding member bonding the base and the wavelength conversion member, A thickness of the wavelength conversion member is less than 100 μm. The wavelength conversion module configured as described above can have high reliability. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a top view of a wavelength conversion module according to the present disclosure. FIG. 2A is a schematic cross-sectional view of a base used for a wavelength conversion module base. FIG. 2B is a schematic cross-sectional view of a base of another embodiment. FIG. 2C is a schematic cross-sectional view of a base of yet another embodiment. FIG. 3A is a schematic cross-sectional view taken along line A-A of the wavelength conversion module illustrated in FIG. 1. FIG. 3B is an enlarged cross-sectional view of a portion of the cross-sectional view of FIG. 3A. FIG. 4A is a flowchart illustrating a process of a manufacturing method for the wavelength conversion module. FIG. 4B is a schematic cross-sectional view illustrating a state after a wavelength conversion member preparation step. FIG. 4C is a schematic cross-sectional view illustrating a state after a first film formation step. FIG. 4D is a schematic cross-sectional view illustrating a state after a grinding polishing preparation step. FIG. 4E is a schematic cross-sectional view illustrating a state after a grinding polishing step. FIG. 4F is a schematic cross-sectional view illustrating a state after a second film formation preparation step. FIG. 4G is a schematic cross-sectional view illustrating a state after a second film formation step. FIG. 4H is a schematic cross-sectional view illustrating a state after a dicing preparation step. FIG. 4I is a schematic cross-sectional view illustrating a state after a dicing C) step. FIG. 5 is a flowchart of the manufacturing method for the wavelength conversion module. FIG. 6 is a graph showing a relationship between an upper limit excitation input and a thickness of the wavelength conversion member in the wavelength conversion module according to the present disclosure. DETAILED DESCRIPTION Hereinafter, exemplary embodiments and examples for carrying out the present disclosure will be described with reference to the drawings. Note that the wavelength conversion module described below is merely intended to embody the technical concept of the present disclosure, and the present disclosure is not limited to the following features unless otherwise specified. In each drawing, members having identical functions may be denoted by the same reference signs. In view of the ease of explanation or understanding of the points of view, the exemplary embodiments and examples may be illustrated separately for convenience, but the partial substitutions or combinations of the configurations illustrated in different exemplary embodiments and examples are possible. In the exemplary embodiments and examples described below, descriptions of ma