JP2019216178A - Light-emitting device - Google Patents

Abstract

To provide a light-emitting device that comprises an optical member and can improve reliability.SOLUTION: A light-emitting device 1 comprises a mounting substrate 2, a light-emitting element 3, a spacer 4, a cover 5, an optical member 9, and a junction 10. The cover 5 is disposed on the spacer 4 so as to cover the light-emitting element 3. The cover 5 transmits ultraviolet light emitted from the light-emitting element 3. The optical member 9 is disposed on the cover 5. The optical member 9 includes an optical function part 90 and a projection 93. The optical function part 90 overlaps with the light-emitting device 3 in a thickness direction D1 of the mounting substrate 2 ans transits ultraviolet light emitted from the light-emitting element 3. The projection 93 projects from the optical function part 90 to the outside in a plan view from the thickness direction D1 and overlaps with the spacer 4 in the thickness direction D1. The junction 10 lies between the projection 93 and the cover 5 in the thickness direction D1 to join the projection 93 to the cover 5.SELECTED DRAWING: Figure 2

Description

  The present invention relates generally to light emitting devices, and more particularly, to light emitting devices that include light emitting elements that emit ultraviolet light.

  Conventionally, a light emitting device including a mounting substrate, an ultraviolet light emitting element, a spacer, and a cover has been proposed (Patent Document 1). The ultraviolet light emitting element is mounted on a mounting board. The spacer is disposed on the mounting board. The spacer has a through-hole that exposes the ultraviolet light emitting element. The cover is disposed on the spacer so as to close the through hole of the spacer.

  In the light emitting device, a package for accommodating an ultraviolet light emitting element is constituted by the mounting substrate, the spacer, and the cover.

JP-A-2006-127249

  In a light emitting device including an ultraviolet light emitting element, it may be desired to control the distribution of ultraviolet light emitted from the ultraviolet light emitting element by an optical member such as a lens disposed outside the package. However, in a light emitting device including an ultraviolet light emitting element, when a lens is fixed to another member by an adhesive, an adhesive portion bonding the lens to the other member is exposed to ultraviolet light emitted from the ultraviolet light emitting element. There is a concern that the reliability deteriorates due to aging.

  An object of the present invention is to provide a light emitting device including an optical member and capable of improving reliability.

  A light-emitting device according to one embodiment of the present invention includes a mounting substrate, a light-emitting element, a spacer, a cover, an optical member, and a joint. The light emitting element is disposed on the mounting substrate and emits ultraviolet light. The spacer has a frame shape and is arranged on the mounting substrate and surrounds the light emitting element. The cover is disposed on the spacer so as to cover the light emitting element. The cover transmits ultraviolet light emitted from the light emitting device. The optical member is disposed on the cover. The optical member has an optical function part and a protruding part. The optical function part overlaps the light emitting element in a thickness direction of the mounting substrate and transmits ultraviolet light emitted from the light emitting element. The projecting portion projects outward from the optical function portion in a plan view from the thickness direction, and at least partially overlaps the spacer in the thickness direction. The joining part is interposed between the projection and the cover in the thickness direction, and joins the projection and the cover.

  In the light emitting device of the present invention, it is possible to provide an optical member and improve the reliability.

FIG. 1 is a plan view of a light emitting device according to one embodiment of the present invention. FIG. 2 is a sectional view taken along line XX of FIG. FIG. 3 is a sectional view of a light emitting element in the light emitting device of the above. FIG. 4 is a process sectional view for describing the method for manufacturing the light emitting device of the above. FIG. 5 is a sectional view of a light emitting device according to a first modification of the embodiment of the present invention. FIG. 6 is a sectional view of a light emitting device according to a second modification of the embodiment of the present invention. FIG. 7 is a sectional view of a light emitting device according to a third modification of the embodiment of the present invention. FIG. 8 is a sectional view of a light emitting device according to Modification 4 of one embodiment of the present invention. FIG. 9 is a cross-sectional view of a light emitting device according to Modification Example 5 of one embodiment of the present invention.

  Each drawing described in the following embodiments and the like is a schematic drawing, and the ratio of the size and thickness of each component does not necessarily reflect the actual dimensional ratio.

(Embodiment)
(1) Overall Configuration of Light Emitting Device Hereinafter, a light emitting device 1 according to an embodiment will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, the light emitting device 1 according to the embodiment includes a mounting substrate 2, a light emitting element 3, a spacer 4, a cover 5, an optical member 9, and a joint 10. The light emitting element 3 is disposed on the mounting substrate 2. The spacer 4 has a frame shape and is disposed on the mounting substrate 2 and surrounds the light emitting element 3. The cover 5 is disposed on the spacer 4 so as to cover the light emitting element 3. The cover 5 transmits ultraviolet rays emitted from the light emitting element 3. The optical member 9 is arranged on the cover 5.

In the light emitting device 1, the package cover member 6 includes the spacer 4 and the cover 5. In the package cover member 6, the spacer 4 and the cover 5 are joined. The light emitting device 1 includes a package 7 including a mounting substrate 2 and a package cover member 6. In the light emitting device 1, a space 8 surrounded by the mounting substrate 2, the spacer 4, and the cover 5 has an inert gas atmosphere. The inert gas atmosphere is, for example, an N ₂ gas atmosphere. In the light emitting device 1, the optical member 9 and the cover 5 are joined by the joint 10.

  The mounting substrate 2 is a mounting substrate on which the light emitting element 3 is mounted, and has a first conductor 21 and a second conductor 22. The mounting substrate 2 has a first bonding metal layer 23 for bonding to the package cover member 6. The light emitting element 3 has a first electrode 31 electrically connected to the first conductor 21 and a second electrode 32 electrically connected to the second conductor 22. The light emitting element 3 is flip-chip mounted on the mounting substrate 2.

  In the light emitting device 1, the first electrode 31 and the first conductor 21 are joined by a first joint 61, and the second electrode 32 and the second conductor 22 are joined by a second joint 62. . In the light emitting device 1, the second bonding metal layer 46 provided on the spacer 4 and the first bonding metal layer 23 of the mounting board 2 are bonded by the third bonding portion 63. In the light emitting device 1, the spacer 4 is joined to the mounting board 2 through the third joint 63 over the entire circumference. In the light emitting device 1, each of the first joint 61, the second joint 62, and the third joint 63 is made of AuSn.

  The light emitting device 1 can be used, for example, mounted on a wiring board. The wiring board is a mother board. The wiring board can be formed, for example, from a metal-based printed wiring board.

(2) Each component of the light emitting device Next, each component of the light emitting device 1 will be described with reference to the drawings.

(2.1) Mounting board The mounting board 2 is a board on which the light emitting element 3 is mounted. In the light emitting device 1, one light emitting element 3 is mounted on a mounting board 2. The mounting substrate 2 is larger than the light emitting element 3 in a plan view.

  The mounting substrate 2 includes a support 20, a first conductor 21, a second conductor 22, and a first bonding metal layer 23 supported by the support 20.

  The support 20 has a flat plate shape, and has a front surface 201 and a back surface 202 on opposite sides in the thickness direction. The outer peripheral shape of the support 20 is, for example, a square shape. The mounting substrate 2 is a ceramic substrate, and the support 20 is formed of AlN ceramic. The support 20 has a function of supporting the first conductor 21, the second conductor 22, and the first bonding metal layer 23.

  The first conductor 21, the second conductor 22, and the first bonding metal layer 23 are formed on the surface 201 of the support 20.

  The first conductor 21 is a conductive layer that is electrically connected to the first electrode 31 of the light emitting element 3. The second conductor 22 is a conductive layer that is electrically connected to the second electrode 32 of the light emitting element 3.

  The first bonding metal layer 23 surrounds the first conductor 21 and the second conductor 22 in plan view. The first bonding metal layer 23 is formed along the outer periphery of the support 20. The planar shape of the first bonding metal layer 23 is a rectangular frame shape.

  Each of the first conductor portion 21, the second conductor portion 22, and the first bonding metal layer 23 includes, for example, a Ti film on the surface 201 of the support 20, a Pt film on the Ti film, and a Pt film on the Ti film. And a laminated film of the above Au film.

  The mounting board 2 further includes a first external connection electrode 24 and a second external connection electrode 25, and a first through wiring 26 and a second through wiring 27 formed to penetrate in the thickness direction of the support 20. In. The first external connection electrode 24 and the second external connection electrode 25 are formed on the back surface 202 of the support 20. The first external connection electrode 24 is electrically connected to the first conductor 21 via the first through wiring 26. The second external connection electrode 25 is electrically connected to the second conductor 22 via the second through wiring 27. Each of the first external connection electrode 24 and the second external connection electrode 25 includes, for example, a Ti film on the back surface 202 of the support 20, a Pt film on the Ti film, and an Au film on the Pt film. It can be composed of a laminated film. The material of each of the first through wiring 26 and the second through wiring 27 is, for example, W, Cu, or the like.

(2.2) Light-Emitting Element The light-emitting element 3 is an ultraviolet LED chip that emits ultraviolet light in the UV-C wavelength range. The emission peak wavelength of the ultraviolet LED chip is, for example, 275 nm. The chip size of the ultraviolet LED chip is, for example, 1 mm □ (1 mm × 1 mm). The thickness of the ultraviolet LED chip is, for example, 100 μm.

  As shown in FIG. 3, the light emitting element 3 includes a substrate 30, a semiconductor multilayer film 39, a first electrode 31, and a second electrode 32.

  The substrate 30 has a first surface 301 and a second surface 302 on opposite sides in the thickness direction. The outer peripheral shape of the substrate 30 is a square shape. The substrate 30 supports the semiconductor multilayer film 39.

  The semiconductor multilayer film 39 is formed on the first surface 301 of the substrate 30. The semiconductor multilayer film 39 includes a first conductivity type semiconductor layer 33, a light emitting layer 34, and a second conductivity type semiconductor layer 35. In the semiconductor multilayer film 39, the first conductivity type semiconductor layer 33, the light emitting layer 34, and the second conductivity type semiconductor layer 35 are arranged in this order from the substrate 30 side. The outer peripheral shape of the first conductivity type semiconductor layer 33 has the same size as the outer peripheral shape of the substrate 30. The outer peripheral shape of each of the light emitting layer 34 and the second conductive type semiconductor layer 35 is smaller than the outer peripheral shape of the first conductive type semiconductor layer 33.

  In the light emitting element 3, the first electrode 31 is electrically connected to the first conductivity type semiconductor layer 33, and the second electrode 32 is electrically connected to the second conductivity type semiconductor layer 35. The first electrode 31 includes a first ohmic electrode layer 31A and a first pad electrode layer 31B.

  The first ohmic electrode layer 31 </ b> A is formed on the surface 331 of the first conductivity type semiconductor layer 33 in order to obtain ohmic contact with the first conductivity type semiconductor layer 33. The first pad electrode layer 31B is formed so as to cover the first ohmic electrode layer 31A in order to join the first pad electrode layer 31B to the mounting substrate 2 via the first joining portion 61 made of, for example, AuSn.

  The second electrode 32 includes a second ohmic electrode layer 32A and a second pad electrode layer 32B. The second ohmic electrode layer 32A is formed on the surface 351 of the second conductive type semiconductor layer 35 in order to obtain ohmic contact with the second conductive type semiconductor layer 35. The second pad electrode layer 32B is formed so as to cover the second ohmic electrode layer 32A in order to join the second pad electrode layer 32B to the mounting substrate 2 via the second joining portion 62 made of, for example, AuSn.

In the light emitting element 3, the substrate 30 is, for example, a sapphire substrate. The first conductivity type semiconductor layer 33 is, for example, an n-type Al _0.60 Ga _0.40 N layer. The light emitting layer 34 has, for example, a multiple quantum well structure in which a plurality (for example, four) barrier layers and a plurality (for example, four) well layers are alternately arranged in the thickness direction of the substrate 30. Each of the plurality of well layers is, for example, an Al _0.45 Ga _0.55 N layer. Each of the plurality of barrier layers is, for example, an Al _0.60 Ga _0.40 N layer. The second conductivity type semiconductor layer 35 includes, for example, a p-type Al _0.80 Ga _0.20 N layer and a p-type GaN layer. The semiconductor multilayer film 39 includes a buffer layer (for example, an AlN layer) interposed between the substrate 30 and the first conductivity type semiconductor layer 33. The light extraction surface of the light emitting element 3 includes the second surface 302 of the substrate 30.

(2.3) Package Cover Member The package cover member 6 includes the spacer 4 and the cover 5 as described above.

  The spacer 4 includes a first surface 41 facing the cover 5 and a second surface 42 opposite to the cover 5. In the light emitting device 1, the spacer 4 is a member interposed between the mounting board 2 and the cover 5. Therefore, the second surface 42 of the spacer 4 faces the mounting substrate 2. In the light emitting device 1, the light emitting element 3 is arranged inside the spacer 4. The thickness (height) of the spacer 4 in the thickness direction D <b> 1 of the mounting board 2 is larger than the thickness of the light emitting element 3.

  The spacer 4 has a frame shape. The outer peripheral shape of the spacer 4 in plan view (the outer peripheral shape of the spacer 4 as viewed from the thickness direction of the mounting substrate 2) is a square shape. The spacer 4 is smaller than the mounting substrate 2 in a plan view. More specifically, the outer peripheral shape of the spacer 4 in plan view is smaller than the outer peripheral shape of the mounting board 2 in plan view. In other words, the outer peripheral line of the spacer 4 in plan view is inside the outer peripheral line of the mounting board 2 in plan view.

  The spacer 4 has a first surface 41, a second surface 42, an inner peripheral surface 43, and an outer peripheral surface 44. The first surface 41 faces the cover 5 in the thickness direction D1. The second surface 42 faces the mounting substrate 2 in the thickness direction D1. The inner peripheral surface 43 is connected to the inner periphery of the first surface 41 and the inner periphery of the second surface 42. The outer peripheral surface 44 connects the outer periphery of the first surface 41 and the outer periphery of the second surface 42. The inner peripheral surface 43 includes an inclined surface 430 whose inner angle with the second surface 42 is an acute angle. The inner peripheral surface 43 includes four inclined surfaces 430. The four inclined surfaces 430 are arranged along the inner periphery of the second surface 42 of the spacer 4. As a result, the opening area of the spacer 4 gradually increases as the distance from the second surface 42 to the first surface 41 increases in the thickness direction D1 of the mounting substrate 2. The opening area of the spacer 4 gradually increases as the distance from the mounting substrate 2 in the thickness direction D1 of the mounting substrate 2 increases. In the light emitting device 1, the spacer 4 is formed of silicon, and the inner peripheral surface 43 of the spacer 4 has a function of a reflecting surface that reflects the ultraviolet light emitted from the light emitting element 3 to the cover 5 side. In other words, in the light emitting device 1, the spacer 4 also functions as a reflector that reflects the ultraviolet light emitted from the light emitting element 3 toward the cover 5.

  The four inclined surfaces 430 of the spacer 4 are formed on the silicon substrate by anisotropic etching using the crystal plane orientation dependence of the etching rate of the silicon substrate. The first surface 41 of the spacer 4 is a (100) surface, and the four inclined surfaces 430 are {111} surfaces. Here, an etchant used for performing anisotropic etching is, for example, a TMAH solution heated to a predetermined temperature (for example, 85 ° C.). The etching solution is not limited to the TMAH solution, and another alkaline solution (for example, a KOH solution) may be used.

  The light emitting device 1 includes a silicon oxide film 45 interposed between the second surface 42 of the spacer 4 and the second bonding metal layer 46. The second bonding metal layer 46 is composed of, for example, a laminated film of an Al film 461 and an Au film 462.

  The cover 5 is flat. The cover 5 has a first main surface 51 on the spacer 4 side and a second main surface 52 on the opposite side to the spacer 4. The outer peripheral shape of the cover 5 in a plan view (the outer peripheral shape of the cover 5 viewed from the thickness direction of the cover 5) is, for example, a square shape. The cover 5 is smaller than the mounting board 2 in a plan view. More specifically, the outer peripheral shape of the cover 5 in plan view is smaller than the outer peripheral shape of the mounting board 2 in plan view. In other words, the outer peripheral line of the cover 5 in plan view is inside the outer peripheral line of the mounting board 2 in plan view.

  The cover 5 is formed of glass. More specifically, the cover 5 is formed of glass that transmits ultraviolet light emitted from the ultraviolet LED chip as the light emitting element 3.

The glass forming the cover 5 contains an alkaline component. The alkaline component is, for example, Na, K, Na ₂ O, K ₂ O or the like. Here, the glass forming the cover 5 is borosilicate glass.

  In the package cover member 6, the spacer 4 and the cover 5 are directly joined. “Directly joined” means that they are joined without using a joining material or the like. The spacer 4 and the cover 5 are directly joined by anodic joining. The fact that the spacer 4 and the cover 5 are directly bonded by anodic bonding is, for example, the result of observation of a cross-sectional TEM image (Cross-Sectional Transmission Electron Microscope Image), the composition analysis by the EDX method (Energy Dispersive X-ray Spectroscopy). As a result, it can be confirmed by a depth profile or the like of the element measured by SIMS (Secondary Ion Mass Spectroscopy).

(2.4) Optical Member The optical member 9 is disposed on the cover 5. In other words, the optical member 9 is disposed on the second main surface 52 side of the cover 5 (the side opposite to the spacer 4 side). In short, the optical member 9 is arranged outside the package 7. The optical member 9 has a property of transmitting ultraviolet light emitted from the light emitting element 3. Here, “having translucency” means that the transmittance for ultraviolet rays emitted from the light emitting element 3 is 50% or more, preferably 70% or more, more preferably 90% or more. The material of the optical member 9 is an inorganic material. More specifically, the optical member 9 is formed of, for example, synthetic quartz.

  The optical member 9 controls the distribution of ultraviolet light emitted from the light emitting element 3. The optical member 9 has an optical function part 90 and a projecting part 93. The optical function part 90 and the protruding part 93 are formed of the same material and are integrated. The optical function part 90 overlaps the light emitting element 3 in the thickness direction D1 of the mounting substrate 2 and transmits the ultraviolet light emitted from the light emitting element 3. The protruding portion 93 protrudes outward from the optical function portion 90 in a plan view from the thickness direction D1, and overlaps the spacer 4 in the thickness direction D1. The joining portion 10 is interposed between the projecting portion 93 and the cover 5 in the thickness direction D1 of the mounting board 2 and joins the projecting portion 93 and the cover 5.

  The optical function part 90 is a part having a function as a lens. In plan view from the thickness direction D1 of the mounting substrate 2, the outer peripheral shape of the optical function unit 90 is substantially circular. The optical function part 90 is larger than the light emitting element 3 in a plan view from the thickness direction D1 of the mounting substrate 2. The optical function part 90 is larger than the inner peripheral shape of the second surface 42 of the spacer 4 in a plan view from the thickness direction D1 of the mounting board 2. The optical function section 90 has a first surface 91 on the cover 5 side and a second surface 92 on the opposite side to the cover 5. The lens is a condenser lens. More specifically, the lens is a plano-convex aspheric lens. Therefore, in the optical function part 90, the first surface 91 is a flat surface, and the second surface 92 is a convex curved surface (aspheric surface).

  The protruding portion 93 is, for example, a portion used to join the optical member 9 and the cover 5. The protrusion 93 protrudes from the entire outer periphery of the optical function unit 90. The thickness of the protruding portion 93 in the thickness direction D1 of the mounting substrate 2 is smaller than the maximum thickness of the optical function portion 90 in the thickness direction D1 of the mounting substrate 2. The protruding portion 93 has a first surface 931 on the cover 5 side and a second surface 932 on the opposite side to the cover 5. In the protruding portion 93, each of the first surface 931 and the second surface 932 is a flat surface. In the optical member 9, the first surface 931 of the protrusion 93 is connected to the first surface 91 of the optical function unit 90, and the first surface 931 and the first surface 91 are located on the same plane ( It is flush). In the optical member 9, the second surface 932 of the protrusion 93 is connected to the second surface 92 of the optical function unit 90, and the boundary between the second surface 932 and the second surface 92 is defined by the optical function unit. 90 is determined by the outer peripheral shape of the second surface 92.

  In plan view from the thickness direction D1 of the mounting board 2, the outer peripheral shape of the protrusion 93 is, for example, a square shape. The outer peripheral shape of the protrusion 93 is the same as the outer peripheral shape of the cover 5. Therefore, the outer peripheral shape of the optical member 9 is the same as the outer peripheral shape of the cover 5 in a plan view from the thickness direction D1 of the mounting substrate 2.

(2.5) Bonding part The bonding part 10 is interposed between the protrusion 93 of the optical member 9 and the cover 5 in the thickness direction D1 of the mounting board 2 and bonds the protrusion 93 and the cover 5. . The light emitting device 1 includes a plurality (four) of the joints 10. The plurality of joints 10 are arranged apart from each other on the second main surface 52 of the cover 5 in a direction along the outer periphery of the cover 5. More specifically, the plurality of joints 10 are arranged so as to correspond to the four corners of the second main surface 52 of the cover 5 on a one-to-one basis. Thus, in the light emitting device 1, the optical function part 90 of the optical member 9 faces the cover 5 only through the space S1 in the thickness direction D1 of the mounting substrate 2.

  In a plan view from the thickness direction D1 of the mounting substrate 2, the outer peripheral shape of each of the plurality of joints 10 is, for example, a circular shape. The plurality of joint portions 10 have the same size in plan view from the thickness direction D1, but may have different sizes.

  The joint 10 includes an adhesive layer 13. The adhesive layer 13 contains a resin. Here, the adhesive layer 13 is formed using a resin-based adhesive. The resin adhesive is, for example, an epoxy resin adhesive.

  The joint 10 includes a first light-shielding layer 11 and a second light-shielding layer 12. The first light-shielding layer 11 is interposed between the adhesive layer 13 and the cover 5, and shields ultraviolet light emitted from the light-emitting element 3. The second light shielding layer 12 is interposed between the adhesive layer 13 and the protruding portion 93, and shields the ultraviolet light emitted from the light emitting element 3 from light. The function of blocking ultraviolet rays is realized by, for example, at least one of reflection, absorption, and scattering of ultraviolet rays.

  Each of the first light shielding layer 11 and the second light shielding layer 12 is made of metal. The first light shielding layer 11 is preferably formed of a metal having good adhesion to the cover 5 and the adhesive layer 13. The second light-shielding layer 12 is preferably formed of a metal having good adhesion to the protrusion 93 of the optical member 9 and the adhesive layer 13. The metal of each of the first light shielding layer 11 and the second light shielding layer 12 is, for example, Cr. The reflectance of Cr to ultraviolet light emitted from the light emitting element 3 is less than 50%. In the joint portion 10, the thickness of the first light shielding layer 11 and the thickness of the second light shielding layer 12 are the same.

  Regarding the bonding portion 10, the adhesive layer 13 is accommodated in the first light shielding layer 11 and the second light shielding layer 12 in plan view from the thickness direction D1 of the mounting substrate 2. Here, “contained in the first light-shielding layer 11 and the second light-shielding layer 12” means that the adhesive layer 13 and the second light-shielding layer 11 have the same shape. 12 includes the same shape. In the light emitting device 1 according to the embodiment, the area of the adhesive layer 13 and the area of the first light shielding layer 11 are the same in a plan view from the thickness direction D1 of the mounting substrate 2. In the light emitting device 1, the area of the adhesive layer 13 and the area of the second light shielding layer 12 are the same in plan view from the thickness direction D1 of the mounting substrate 2.

  The adhesive layer 13 is housed in the protrusion 93 in a plan view from the thickness direction D1 of the mounting board 2. Thus, the adhesive layer 13 does not overlap with the optical function part 90 in a plan view from the thickness direction D1 of the mounting substrate 2 and is located outside the inner periphery of the first surface 41 of the spacer 4.

(3) Method for Manufacturing Light-Emitting Device Hereinafter, a method for manufacturing the light-emitting device 1 will be briefly described with reference to FIG.

  In the method for manufacturing the light emitting device 1, a plurality (four) of the first light shielding layers 11 are formed on the second main surface 52 of the cover 5. Thereafter, the package cover member 6 is formed by joining the spacer 4 and the cover 5. Then, before bonding the package cover member 6 and the mounting substrate 2, as shown in FIG. 4, a silicon oxide film 45 and a second bonding metal layer 46 are previously formed on the second surface 42 of the spacer 4. Is provided. On the other hand, on the first conductor part 21, the second conductor part 22, and the first bonding metal layer 23 of the mounting board 2, the first bonding part 61, the second bonding part 62, and the third bonding part 63 are respectively formed. A first AuSn layer 71, a second AuSn layer 72, and a third AuSn layer 73 are provided. Here, the first barrier layer 81, the second barrier layer 81 and the second AuSn layer 73 are located between the first conductor section 21, the second conductor section 22, and the first bonding metal layer 23 and the first AuSn layer 71, the second AuSn layer 72, and the third AuSn layer 73. A barrier layer 82 and a third barrier layer 83 are provided. The material of the first barrier layer 81, the second barrier layer 82, and the third barrier layer 83 is, for example, Pt. Further, a first Au layer 121, a second Au layer 122, and a third Au layer 123 are provided on the first AuSn layer 71, the second AuSn layer 72, and the third AuSn layer 73, respectively. The first Au layer 121, the second Au layer 122, and the third Au layer 123 are layers provided for suppressing the oxidation of Sn of the first AuSn layer 71, the second AuSn layer 72, and the third AuSn layer 73. The thickness of the first Au layer 121, the second Au layer 122, and the third Au layer 123 is such that when the first AuSn layer 71, the second AuSn layer 72, and the third AuSn layer 73 are melted, the first AuSn layer 71, the second AuSn layer 72, and the Au is thermally diffused into the 3AuSn layer 73, and the first conductor portion 21, the second conductor portion 22, and the first bonding metal layer 23 are bonded to the first electrode 31, the second electrode 32, and the second bonding metal layer 46. Is decided to be done. Hereinafter, a laminated film of the first barrier layer 81, the first AuSn layer 71, and the first Au layer 121 is referred to as a first bonding layer 131, and a laminated film of the second barrier layer 82, the second AuSn layer 72, and the second Au layer 122. The film is referred to as a second bonding layer 132. Hereinafter, a laminated film of the third barrier layer 83, the third AuSn layer 73, and the third Au layer 123 is referred to as a third bonding layer 133. The first bonding layer 131 only needs to include at least the first AuSn layer 71, and is not limited to a laminated film, and may be a single-layer film. The second bonding layer 132 only needs to include at least the second AuSn layer 72, and is not limited to a laminated film, and may be a single-layer film. The third bonding layer 133 only needs to include at least the third AuSn layer 73, and is not limited to a laminated film, and may be a single-layer film.

  In the method for manufacturing the light emitting device 1, the light emitting element 3 is mounted on the mounting substrate 2 before the package cover member 6 and the mounting substrate 2 are bonded, and then the package cover member 6 and the mounting substrate 2 are bonded. I do.

  When mounting the light emitting element 3 on the mounting substrate 2, the first electrode 31 and the second electrode 32 of the light emitting element 3 are in contact with the first bonding layer 131 and the second bonding layer 132 on the mounting substrate 2. The first and second AuSn layers 71 and 72 are melted while performing appropriate heating and pressurization in the state of being overlapped as described above, and then cooled and solidified to form the first and second bonding portions 61 and 62. I do. Here, when the first AuSn layer 71 melts, Au diffuses from the first Au layer 121 into the molten AuSn, and the Au composition ratio in the molten AuSn increases. When the second AuSn layer 72 melts, Au diffuses from the second Au layer 122 into the molten AuSn, and the composition ratio of Au in the molten AuSn increases.

  When bonding the package cover member 6 and the mounting board 2, the second bonding metal layer 46 provided on the package cover member 6 and the third bonding layer 133 on the mounting board 2 are in contact with each other. In the superimposed state, the third AuSn layer 73 is melted while performing appropriate heating and pressurization, and then cooled and solidified to form the third bonding portion 63. When the third AuSn layer 73 melts, Au diffuses from the third Au layer 123 into the molten AuSn, and the Au composition ratio in the molten AuSn increases.

  After joining the package cover member 6 and the mounting board 2 as described above, an adhesive that is the basis of the adhesive layer 13 is applied onto each of the plurality of first light-shielding layers 11 of the cover 5, and the plurality of 2 The optical member 9 having the light-shielding layer 12 formed on the first surface 931 of the projection 93 is joined to the cover 5.

(4) Effect The light emitting device 1 according to the embodiment includes the mounting substrate 2, the light emitting element 3, the spacer 4, the cover 5, the optical member 9, and the joint 10. The light emitting element 3 is disposed on the mounting substrate 2 and emits ultraviolet light. The spacer 4 has a frame shape and is arranged on the mounting substrate 2 and surrounds the light emitting element 3. The cover 5 is arranged on the spacer 4 so as to cover the light emitting element 3. The cover 5 transmits ultraviolet light emitted from the light emitting element 3. The optical member 9 is arranged on the cover 5. The optical member 9 has an optical function part 90 and a projecting part 93. The optical function part 90 overlaps the light emitting element 3 in the thickness direction D1 of the mounting substrate 2 and transmits the ultraviolet light emitted from the light emitting element 3. The projecting portion 93 projects outward from the optical function portion 90 in a plan view from the thickness direction D1, and at least partially overlaps the spacer 4 in the thickness direction D1. The joining portion 10 is interposed between the projection 93 and the cover 5 in the thickness direction D1, and joins the projection 93 and the cover 5.

  The light emitting device 1 according to the embodiment includes the optical member 9 and can improve reliability. Here, in the light emitting device 1, the light distribution of the ultraviolet light emitted from the light emitting element 3 can be controlled by the optical function unit 90 of the optical member 9. Further, in the light emitting device 1, there is no portion that deteriorates with time due to ultraviolet rays from the light emitting element 3, such as an adhesive, in a space surrounded by the mounting substrate 2, the spacer 4, and the cover 5. Thus, the light emitting device 1 can have improved reliability.

  Further, in the light emitting device 1 according to the first embodiment, since the bonding portion 10 includes the adhesive layer 13, the protrusion 93 and the cover 5 can be bonded by the adhesive layer 13.

  Further, in the light emitting device 1 according to the first embodiment, the joint 10 further includes the first light shielding layer 11 and the second light shielding layer 12. Thereby, in the light emitting device 1, the ultraviolet rays radiated from the light emitting element 3 and reflected by other members (the mounting substrate 2, the spacer 4, the cover 5, the optical member 9, and the like) are less likely to enter the adhesive layer 13. Therefore, in the light emitting device 1 according to the first embodiment, the deterioration of the adhesive layer 13 due to ultraviolet rays can be further suppressed as compared with the case where the first light shielding layer 11 and the second light shielding layer 12 are not provided, and the reliability is improved. Can be further improved.

(Modification)
The above embodiments are merely one of various embodiments of the present invention. The above embodiment can be variously modified according to the design and the like as long as the object of the present invention can be achieved.

(Modification 1)
Hereinafter, a light emitting device 1a according to a first modification of the embodiment will be described with reference to FIG.

  The basic configuration of the light emitting device 1a according to the first modification is the same as that of the light emitting device 1 according to the embodiment. Regarding the light emitting device 1a according to Modification 1, the same components as those of the light emitting device 1 according to the embodiment are denoted by the same reference numerals, and description thereof will be omitted.

  In the light emitting device 1a according to the first modification, the area of the adhesive layer 13 is smaller than the area of the first light shielding layer 11 and the area of the second light shielding layer 12 in a plan view from the thickness direction D1 of the mounting substrate 2.

  Further, in the light emitting device 1a according to the first modification, the distance L3 between the adhesive layer 13 and the center of the optical function unit 90 in the plan view from the thickness direction D1 of the mounting substrate 2 is different from the first light shielding layer 11 It is longer than the distance L1 from the center of the target function unit 90. Accordingly, in the light emitting device 1a according to the first modification, the ultraviolet light emitted from the light emitting element 3 is less likely to enter the adhesive layer 13 as compared with the light emitting device 1 according to the embodiment.

(Modification 2)
Hereinafter, a light emitting device 1b according to a second modification of the embodiment will be described with reference to FIG.

  The basic configuration of the light emitting device 1b according to Modification 2 is the same as that of the light emitting device 1a according to Modification 1 of the embodiment. Regarding the light emitting device 1b according to the second modification, the same components as those of the light emitting device 1a according to the first modification of the embodiment are denoted by the same reference numerals, and description thereof will be omitted.

  In the light emitting device 1b according to Modification Example 2, the distance (shortest distance) L13 between the adhesive layer 13 and (the outer periphery of) the optical function unit 90 is the first light-shielding when viewed in a plan view from the thickness direction D1 of the mounting substrate 2. It is longer than the distance (shortest distance) L11 between the layer 11 and (the outer periphery of) the optical function part 90. Accordingly, in the light emitting device 1b according to the second modification, the ultraviolet light radiated from the light emitting element 3 is less likely to enter the adhesive layer 13 as compared with the light emitting device 1 according to the embodiment.

(Modification 3)
Hereinafter, a light emitting device 1c according to a third modification of the embodiment will be described with reference to FIG.

  The basic configuration of the light emitting device 1c according to the third modification is the same as that of the light emitting device 1b according to the second modification of the first embodiment. Regarding the light emitting device 1c according to the third modification, the same components as those of the light emitting device 1b according to the second modification of the embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the light emitting device 1c according to Modification 3, the area of the first light shielding layer 11 is larger than the area of the second light shielding layer 12 in a plan view from the thickness direction D1 of the mounting substrate 2. Thereby, in the light emitting device 1c according to the third modification, compared to the light emitting device 1a according to the first modification of the embodiment, the ultraviolet light emitted from the light emitting element 3 is less likely to enter the adhesive layer 13.

(Modification 4)
Hereinafter, a light emitting device 1d according to a modification 4 of the embodiment will be described with reference to FIG.

  The basic configuration of the light emitting device 1d according to Modification 4 is the same as that of the light emitting device 1a according to Modification 1 of Embodiment 1. Regarding the light emitting device 1d according to Modification 4, the same components as those of the light emitting device 1a according to Modification 1 of the embodiment are denoted by the same reference numerals, and description thereof will be omitted.

  In the light emitting device 1d according to Modification 4, the thickness of the first light shielding layer 11 is larger than the thickness of the second light shielding layer 12. Accordingly, in the light emitting device 1d according to Modification 4, compared to the light emitting device 1a according to Modification 1 of the embodiment, the ultraviolet light emitted from the light emitting element 3 is less likely to enter the adhesive layer 13.

(Modification 5)
Hereinafter, a light emitting device 1e according to a fifth modification of the embodiment will be described with reference to FIG.

  The basic configuration of the light emitting device 1e according to the fifth modification is the same as that of the light emitting device 1 according to the first embodiment. Regarding the light emitting device 1e according to Modification 5, the same components as those of the light emitting device 1 according to the embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the light emitting device 1e according to Modification 5, a part of the adhesive layer 13 is moved from the first light shielding layer 11 and the second light shielding layer 12 to the optical function unit 90 side in a plan view from the thickness direction D1 of the mounting substrate 2. And protrudes to the opposite side. This facilitates the manufacture of the light emitting device 1e according to the fifth modification. Further, in the light emitting device 1e according to the fifth modification, it is possible to prevent the area of the adhesive layer 13 from becoming too small.

(Other variations)
For example, in the package cover member 6, the cover 5 is not limited to glass containing an alkali component, and may be formed of, for example, quartz glass or the like. In this case, the spacer 4 and the cover 5 may be joined by a joining portion formed of, for example, low-melting glass. The low melting point glass is a glass having a softening point of 600 ° C. or lower, preferably a glass having a softening point of 500 ° C. or lower, and more preferably a glass having a softening point of 400 ° C. or lower. The low melting point glass is, for example, a glass containing lead oxide (PbO) and boric anhydride (B ₂ O ₃ ) as main components.

  Further, the glass is not limited to borosilicate glass and quartz glass, and may be, for example, soda lime glass, non-alkali glass, or the like.

  Further, the light emitting element 3 is not limited to an ultraviolet LED chip that emits ultraviolet light in the UV-C wavelength range, and may be, for example, an ultraviolet LED chip that emits ultraviolet light in the UV-B wavelength range. Further, the light emitting element 3 may be, for example, an ultraviolet LED chip that emits ultraviolet light in the UV-A wavelength range.

  Further, the number of the light emitting elements 3 arranged inside the spacer 4 on the mounting substrate 2 is not limited to one, and may be plural. When the light emitting devices 1, 1 a to 1 e include a plurality of light emitting elements 3 arranged inside the spacer 4, the plurality of light emitting elements 3 may be the same kind of light emitting element, or the plurality of light emitting elements 3 At least one of the light emitting elements 3 may be a different type of element from the remaining light emitting elements 3. For example, the light-emitting devices 1, 1 a to 1 e each include, as the four light-emitting elements 3, one first ultraviolet LED chip that emits ultraviolet light in the UV-C wavelength range and 3 that emits ultraviolet light in the UV-B wavelength range. And two second ultraviolet LED chips.

  Further, regarding the light emitting devices 1, 1 a to 1 e, the light emitting element 3 may be joined to the mounting substrate 2 by conductive bumps.

  The method of joining the spacer 4 and the cover 5 is not limited to anodic joining, but may be directly joined by, for example, a surface activated joining method. Further, the spacer 4 and the cover 5 may be joined by, for example, a eutectic joining method.

  The material of the spacer 4 is not limited to silicon, and may be, for example, aluminum, an aluminum alloy, or the like.

  Further, the spacer 4 is not limited to the case where the spacer 4 is smaller than the mounting substrate 2 in a plan view from the thickness direction D1 of the mounting substrate 2. For example, the spacer 4 may be the same size as the mounting substrate 2 in a plan view. It may be larger than the mounting board 2 in view.

  Further, the spacer 4 is not limited to a configuration in which the opening area gradually increases as the distance from the second surface 42 to the first surface 41 increases in the thickness direction D1 of the mounting substrate 2. It may be increasing. Further, the opening area of the spacer 4 may be substantially constant irrespective of the position in the thickness direction D1 of the mounting board 2, for example.

  Further, the lens constituting the optical function section 90 of the optical member 9 is not limited to a plano-convex lens, and may be, for example, a Fresnel lens. Further, the lens is not limited to an aspherical lens, and may be, for example, a spherical lens. The lens is not limited to a plano-convex lens, and may be, for example, a biconvex lens, a plano-concave lens, or the like. Further, the optical function unit 90 is not limited to a lens, and may be, for example, a lens array, a prism, or the like.

  The optical member 9 is not limited to synthetic quartz, and may be, for example, quartz glass, borosilicate glass, or the like.

  Further, the projecting portion 93 of the optical member 9 is not limited to the case where the entire projecting portion 93 overlaps the spacer 4 in the thickness direction D1 of the mounting board 2, and at least a part of the projecting portion 93 may overlap the spacer 4.

  Further, in the light emitting device 1, in a plan view from the thickness direction D <b> 1 of the mounting substrate 2, the optical function unit 90 of the optical member 9 and the bonding unit 10 do not necessarily have to be separated from each other, and The unit may overlap with the optical function unit 90. In the light emitting device 1, a part of the adhesive layer 13 protrudes from the first light shielding layer 11 and the second light shielding layer 12 toward the optical function part 90 in a plan view from the thickness direction D1 of the mounting substrate 2. Is also good.

  The metal of each of the first light shielding layer 11 and the second light shielding layer 12 is not limited to Cr but may be, for example, Ti, Mo, or the like. Further, the first light shielding layer 11 and the second light shielding layer 12 may be different metals. Further, each of the first light shielding layer 11 and the second light shielding layer 12 may be made of an alloy. Further, each of the first light-shielding layer 11 and the second light-shielding layer 12 may be a glass that absorbs ultraviolet light from the light emitting element 3.

  Further, the joint 10 may be made of a low-melting glass. The joint 10 may include solder. Further, the joint 10 may be formed of a plurality of metal layers that are overlapped and joined to each other in the thickness direction D1 of the mounting board 2.

  Further, the light emitting devices 1, 1 a to 1 e may include a zener diode connected in anti-parallel to the light emitting element 3. Thus, the light emitting devices 1, 1a to 1e can have improved electrostatic resistance. It is preferable that the Zener diode be mounted on the mounting substrate 2 in the package 7, for example.

(Summary)
The following aspects are disclosed from the embodiments and the like described above.

  The light emitting device (1; 1a; 1b; 1c; 1d; 1e) according to the first embodiment includes a mounting substrate (2), a light emitting element (3), a spacer (4), a cover (5), and an optical element. A member (9) and a joint (10) are provided. The light emitting element (3) is disposed on the mounting substrate (2) and emits ultraviolet light. The spacer (4) has a frame shape and is arranged on the mounting substrate (2) and surrounds the light emitting element (3). The cover (5) is arranged on the spacer (4) so as to cover the light emitting element (3). The cover (5) transmits ultraviolet light emitted from the light emitting element (3). The optical member (9) is arranged on the cover (5). The optical member (9) has an optical function part (90) and a protruding part (93). The optical function part (90) overlaps the light emitting element (3) in the thickness direction (D1) of the mounting substrate (2) and transmits ultraviolet light emitted from the light emitting element (3). The protruding portion (93) protrudes outward from the optical function portion (90) in a plan view from the thickness direction (D1), and at least partially overlaps the spacer (4) in the thickness direction (D1). . The joint (10) is interposed between the protrusion (93) and the cover (5) in the thickness direction (D1), and joins the protrusion (93) and the cover (5).

  In the light emitting device (1; 1a; 1b; 1c; 1d; 1e) according to the first aspect, it is possible to provide the optical member (9) and improve the reliability.

  In the light emitting device (1; 1a; 1b; 1c; 1d; 1e) according to the second aspect, in the first aspect, the bonding portion (10) includes an adhesive layer (13).

  In the light emitting device (1; 1a; 1b; 1c; 1d; 1e) according to the second embodiment, the projection (93) and the cover (5) can be joined by the adhesive layer (13).

  In the light emitting device (1; 1a; 1b; 1c; 1d; 1e) according to the third aspect, in the second aspect, the bonding portion (10) includes a first light shielding layer (11) and a second light shielding layer ( 12). The first light shielding layer (11) is interposed between the adhesive layer (13) and the cover (5), and shields ultraviolet light emitted from the light emitting element (3). The second light-shielding layer (12) is interposed between the adhesive layer (13) and the protrusion (93), and shields ultraviolet light emitted from the light-emitting element (3).

  In the light emitting device (1; 1a; 1b; 1c; 1d; 1e) according to the third embodiment, compared to the case where the first light-shielding layer (11) and the second light-shielding layer (12) are not provided, adhesion by ultraviolet rays is performed. The deterioration of the layer (13) can be further suppressed, and the reliability can be further improved.

  The light emitting device (1; 1a; 1b; 1c; 1d; 1e) according to the fourth aspect is the light emitting device according to the third aspect, wherein each of the first light shielding layer (11) and the second light shielding layer (12) is made of metal. is there.

  In the light emitting device (1; 1a; 1b; 1c; 1d; 1e) according to the fourth embodiment, it is possible to suppress the deterioration of the first light shielding layer (11) and the second light shielding layer (12) due to ultraviolet rays. .

  The light emitting device (1; 1a; 1b; 1c; 1d; 1e) according to the fifth aspect is the light emitting device according to any one of the third and fourth aspects, wherein the adhesive layer (13) includes a resin.

  In the light emitting device (1; 1a; 1b; 1c; 1d; 1e) according to the fifth aspect, the projection (93) and the cover (5) can be joined by a resin joining method.

  In the light-emitting device (1; 1a; 1b; 1c; 1d) according to the sixth aspect, in any one of the third to fifth aspects, the adhesive layer (13) is a flat surface from the thickness direction (D1). It is within the first light shielding layer (11) and the second light shielding layer (12) when viewed.

  In the light emitting device (1; 1a; 1b; 1c; 1d) according to the sixth aspect, the ultraviolet light emitted from the light emitting element (3) is less likely to enter the adhesive layer (13).

  In the light-emitting device (1a; 1b; 1c; 1d) according to the seventh aspect, in the sixth aspect, in plan view from the thickness direction (D1), the area of the adhesive layer (13) is the first light-shielding layer ( 11) and smaller than the area of the second light shielding layer (12).

  In the light-emitting device (1a; 1b; 1c; 1d) according to the seventh aspect, the ultraviolet light emitted from the light-emitting element (3) hardly enters the adhesive layer (13).

  In the light-emitting device (1a; 1b; 1c; 1d; 1e) according to the eighth aspect, in any one of the third to seventh aspects, the adhesive layer (13) in plan view from the thickness direction (D1). ) And the center (L13) of the optical function part (90) are longer than the distance (L11) between the first light shielding layer (11) and the center of the optical function part (90).

  In the light emitting device (1a; 1b; 1c; 1d; 1e) according to the eighth aspect, the ultraviolet light emitted from the light emitting element (3) is less likely to enter the adhesive layer (13).

  In the light emitting device (1; 1a; 1b; 1c; 1d; 1e) according to the ninth aspect, in any one of the second to eighth aspects, the adhesive layer (13) is arranged in the thickness direction (D1). In the projection (93) in plan view.

  In the light emitting device (1; 1a; 1b; 1c; 1d; 1e) according to the ninth aspect, for example, a part of the adhesive layer (13) has a protrusion (93) in plan view from the thickness direction (D1). Ultraviolet rays emitted from the light emitting element (3) are less likely to be incident on the adhesive layer (13) as compared with the case where they protrude and overlap the optical function part (90).

  In the light-emitting device (1; 1a; 1b; 1c; 1d; 1e) according to the tenth aspect, in any one of the first to ninth aspects, the light-emitting element (3) is a UV-C or UV-B An ultraviolet LED chip that emits ultraviolet light in the wavelength range described above.

  In the light emitting device (1; 1a; 1b; 1c; 1d; 1e) according to the tenth aspect, the light emitting element (3) includes an ultraviolet LED chip that emits ultraviolet light in the UV-C or UV-B wavelength range. In the configuration, the light distribution of the ultraviolet light can be controlled by the optical member (9), and the reliability can be improved. The light emitting device (1; 1a; 1b; 1c; 1d; 1e) according to the tenth aspect can be used, for example, in fields such as sterilization, medical treatment, and applications for processing environmental pollutants at high speed.

DESCRIPTION OF SYMBOLS 1 Light-emitting device 2 Mounting board 3 Light-emitting element 4 Spacer 5 Cover 9 Optical member 90 Optical function part 93 Projection part 10 Joint part 11 First light-shielding layer 12 Second light-shielding layer 13 Adhesive layer L1 distance L3 distance L11 distance L13 distance

Claims (10)

A mounting board,
A light emitting element that is disposed on the mounting substrate and emits ultraviolet light,
A frame-shaped spacer arranged on the mounting substrate and surrounding the light-emitting element,
A cover that is disposed on the spacer so as to cover the light emitting element and transmits ultraviolet light emitted from the light emitting element,
An optical function unit that is disposed on the cover, overlaps the light emitting element in the thickness direction of the mounting substrate, and transmits ultraviolet light emitted from the light emitting element, and the optical function in a plan view from the thickness direction. An optical member having a protruding portion that protrudes outward from the functional portion, and at least partially overlaps the spacer in the thickness direction,
A joining portion interposed between the projecting portion and the cover in the thickness direction, and joining the projecting portion and the cover.
Light emitting device. The joint includes an adhesive layer,
The light emitting device according to claim 1. The joint is
A first light-blocking layer interposed between the adhesive layer and the cover and configured to block ultraviolet rays emitted from the light-emitting element;
A second light-shielding layer interposed between the adhesive layer and the protruding portion, and shielding the ultraviolet light emitted from the light-emitting element.
The light emitting device according to claim 2. Each of the first light shielding layer and the second light shielding layer is a metal,
The light emitting device according to claim 3. The adhesive layer contains a resin,
The light emitting device according to claim 3. The adhesive layer is contained in the first light-shielding layer and the second light-shielding layer in plan view from the thickness direction,
The light emitting device according to claim 3. In a plan view from the thickness direction, the area of the adhesive layer is smaller than the area of the first light shielding layer and the area of the second light shielding layer;
A light emitting device according to claim 6. In a plan view from the thickness direction, a distance between the adhesive layer and the center of the optical function unit is longer than a distance between the first light shielding layer and the center of the optical function unit,
The light emitting device according to claim 3. The adhesive layer is accommodated in the protrusion in a plan view from the thickness direction,
A light emitting device according to claim 2. The light emitting element is an ultraviolet LED chip that emits ultraviolet light in a UV-C or UV-B wavelength range,
The light emitting device according to claim 1.

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