JP2015026753A - Semiconductor light emitting device and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor light emitting device and a manufacturing method of the same, which can achieve outgoing beams having a uniform chromaticity distribution and a uniform luminance distribution across a whole area of a light emission surface.SOLUTION: A semiconductor light emitting device comprises: a light emitting element 10 composed of a truncated pyramid-shaped growth substrate 11, and an epitaxial growth layer 15 which is stacked on a bottom face of the growth substrate 11 and includes an active layer 13; a wavelength conversion layer 40 provided so as to cover a top face 21 and a lateral face 22 of the growth substrate 11; a transparent plate 45 arranged on the wavelength conversion layer 40; and a diffusion reflection member 50 arranged to collectively cover lateral faces 25, 41, 48 of the epitaxial growth layer 15 of the light emitting element 10, the wavelength conversion layer 40 and the transparent plate 45. In this case, the light emitting element 10, the wavelength conversion layer 40 and the transparent plate 45 substantially overlap each other in plan view which is viewed from above the transparent plate 45.

Description

  The present invention relates to a semiconductor light-emitting device and a method for manufacturing the same, and more particularly, to a semiconductor light-emitting element as a light-emitting source and to emit wavelength-converted light having a wavelength longer than that of excitation light when excited by light emitted from the semiconductor light-emitting element. The present invention relates to a semiconductor light-emitting device that emits light having a hue different from the emission color of a semiconductor light-emitting element, and a manufacturing method thereof.

  Conventionally, as this type of semiconductor light emitting device, for example, a semiconductor light emitting device having the structure shown in FIG.

  That is, a plurality of flip chip mounting type semiconductor light emitting elements 81 are electrically and mechanically joined to the circuit pattern formed on the mounting substrate 80 via metal bumps 82. A wavelength conversion layer 83 made of a phosphor-containing resin containing a phosphor in a transparent resin is provided so as to integrally cover the upper and side surfaces of each, and a transparent plate 84 is disposed on the wavelength conversion layer 83. Has been. The side surfaces of the wavelength conversion layer 83 and the transparent plate 84 are integrally covered with the diffuse reflection member 85.

  The transparent plate 84 is larger than the mounting region of the plurality of semiconductor light emitting elements 81 located below, and the upper surface (light emitting surface) 86 is subjected to a roughening process.

  Therefore, a part of the light emitted from the upper surface (main light emission surface) 87 of the semiconductor light emitting element 81 of the light source is transmitted through the wavelength conversion layer 83 as it is, and a part of the light passes through the phosphor in the wavelength conversion layer 83. Excitation is performed to emit wavelength-converted light having a wavelength longer than that of the excitation light, and additive color mixing light of a part of the light emitted from the semiconductor light emitting element 81 and the wavelength-converted light is emitted from the roughened surface of the transparent plate 84. The light is emitted from the surface 86 as diffused light.

JP 2012-79840 A

  By the way, the light emitting device disclosed in Patent Document 1 described above is a region directly above the semiconductor light emitting element 81 located below when the light emitting surface 86 of the transparent plate 84 is viewed from above the transparent plate 84 (upward view). In other areas, a difference in hue is observed in the emitted light. That is, when viewed from the top of the semiconductor light emitting device, chromaticity unevenness occurs in the light emitted from the light emitting surface 86 of the transparent plate 84, and the color rendering properties are inferior.

  Specifically, the semiconductor light-emitting element 81 is a blue semiconductor light-emitting element that emits blue light, and the phosphor contained in the wavelength conversion layer 83 is excited by the blue light from the blue semiconductor light-emitting element 81 to complement the blue light. In the case of a yellow phosphor that converts the wavelength into yellow light and emits it, a part of the blue light from the blue semiconductor light emitting element 81 is partly from the region immediately above the blue semiconductor light emitting element 81 on the light exit surface 86 of the transparent plate 84. White light is emitted by additive color mixing of the direct light and the blue light from the blue semiconductor light emitting element 81 with the yellow light whose wavelength is converted by exciting the yellow phosphor in the wavelength conversion layer 83.

  On the other hand, since the blue semiconductor light emitting element 81 is not positioned below the region of the light emitting surface 86 of the transparent plate 84 other than the region directly above the blue semiconductor light emitting element 81, the blue semiconductor light emitting element 81 to the transparent plate 84 Of the blue light traveling toward the lower surface (light incident surface) 88, the amount of light directed to a region other than the region directly above the blue semiconductor light emitting element 81 is extremely small compared to the amount of light directed toward the region directly above the blue semiconductor light emitting element 81. The emitted light becomes yellowish white light with less blue component and more yellow component, and is emitted to the outside.

  At the same time, due to the difference in the amount of blue light directed from the blue semiconductor light emitting element 81 toward the light incident surface 88 of the transparent plate 84, the brightness of the emitted light from the semiconductor light emitting device is increased in the region directly above the blue semiconductor light emitting device 81 and the other regions. The difference arises. That is, luminance unevenness occurs in the emitted light when the light emitting device is viewed from above.

  Note that the chromaticity unevenness and luminance unevenness are suppressed by applying a roughening process to the light emitting surface 86 of the transparent plate 84 to make the emitted light diffused, but as described above. Since the amount of blue light emitted from the blue semiconductor light emitting element 81 and traveling toward the light incident surface 88 of the transparent plate 84 is different, the effect of suppressing chromaticity unevenness and luminance unevenness must be limited.

  In addition, the fact that the transparent plate 84 is larger than the mounting area of the plurality of blue semiconductor light emitting elements 81 positioned below means that the size of the transparent plate 84 is larger than the mounting area of the blue semiconductor light emitting elements 81. The transparent plate 84 has a useless area that does not contribute to the emission of light without chromaticity unevenness and brightness unevenness.

  Accordingly, the present invention was devised in view of the above problems, and its object is to provide a semiconductor light emitting device capable of obtaining emitted light having uniform chromaticity distribution and luminance distribution over the entire light emitting surface, and It is in providing the manufacturing method.

  In order to solve the above-mentioned problem, the invention described in claim 1 of the present invention includes a growth substrate having a truncated pyramid shape and an epitaxial growth layer including an active layer stacked on a bottom surface of the growth substrate. A plurality of semiconductor light emitting devices, a wavelength conversion layer formed on the upper surface and side surfaces of the growth substrate, in which phosphor particles are mixed and dispersed in a first binder, and provided on the wavelength conversion layer. The light scattering particles are mixed and dispersed in the second binder provided so as to integrally cover the transparent plate, the epitaxial growth layer, the wavelength conversion layer, and the transparent plate of the semiconductor light emitting element. The epitaxial growth layer, the wavelength conversion layer, and the transparent plate all have substantially the same outer dimensions in the direction perpendicular to the optical axis of the semiconductor light emitting element, and each side surface. Judges are characterized in that they are positioned substantially on the same plane parallel to the optical axis.

  According to a second aspect of the present invention, there is provided a plurality of semiconductor light emitting devices having a growth substrate having a truncated pyramid shape and an epitaxial growth layer including an active layer stacked on a bottom surface of the growth substrate. A wavelength conversion layer in which phosphor particles are mixed and dispersed in a first binder provided integrally on an upper surface and a side surface of each growth substrate of the plurality of semiconductor light emitting elements; and the wavelength conversion layer And a second binder provided so as to integrally cover each of the epitaxial growth layers, the wavelength conversion layer, and the side surfaces of the transparent plates of the plurality of semiconductor light emitting elements. A diffuse reflection member formed by mixing and dispersing light scattering particles, and the wavelength conversion layer and the transparent plate have substantially the same outer dimensions as mounting regions of the plurality of semiconductor light emitting elements, and the wavelength conversion In addition, each of the side surfaces of the transparent plate and the outermost circumferences of the mounting regions of the plurality of semiconductor light emitting elements are located on substantially the same plane parallel to the optical axis of the semiconductor light emitting element. is there.

  The invention described in claim 3 of the present invention is characterized in that, in claim 1 or 2, both the first binder and the second binder are made of a silicone resin or an epoxy resin. To do.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the light scattering particles may be titanium oxide (TiO ₂ ), zinc oxide (ZnO), boron nitride (B ₂ O ₃ ) and aluminum nitride (AlN).

  Moreover, the invention described in claim 5 of the present invention is characterized in that in any one of claims 1 to 4, the transparent plate is made of one of glass, silicone resin and epoxy resin. To do.

  According to a sixth aspect of the present invention, there is provided a semiconductor light emitting element having a growth substrate having a truncated pyramid shape and an epitaxial growth layer including an active layer stacked on a bottom surface of the growth substrate. A step of applying a wavelength conversion resin in which phosphor particles are mixed and dispersed in a first binder on the upper surface of the growth substrate, and the wavelength conversion resin is uncured and the wavelength conversion resin is applied to the epitaxial growth layer. The wavelength conversion resin crushed by pressing and moving to the epitaxial growth layer side with a transparent plate having substantially the same outer dimensions and flowing down from the upper surface of the growth substrate to the side surface to cover the upper surface and the side surface, and the epitaxial growth layer The light scattering particles are mixed and dispersed in the second binder so as to integrally cover the side surfaces of the wavelength conversion layer after curing of the wavelength conversion resin and the transparent plate. A step of providing a diffuse reflection member, and the side surfaces of the epitaxial growth layer, the wavelength conversion layer, and the transparent plate are positioned on substantially the same plane parallel to the optical axis of the semiconductor light emitting device. It is characterized by this.

  According to a seventh aspect of the present invention, there is provided a plurality of semiconductor light emitting devices each having a growth substrate having a truncated pyramid shape and an epitaxial growth layer including an active layer stacked on a bottom surface of the growth substrate. A step of applying a wavelength conversion resin in which phosphor particles are mixed and dispersed in a first binder so as to cover the upper surface of each of the growth substrates, and the wavelength conversion resin is in an uncured state Each of the wavelength conversion resins crushed by collectively pressing and moving to the epitaxial growth layer side with a transparent plate having substantially the same outer dimensions as the mounting region of the plurality of semiconductor light emitting elements is grown. A step of integrally covering the upper surface and the side surface of each growth substrate by flowing down from the upper surface to the side surface of the substrate, the epitaxial growth layer of each of the plurality of semiconductor light emitting devices, and the wavelength conversion tree A step of providing a diffuse reflection member formed by mixing and dispersing light scattering particles in the second binder so as to integrally cover the respective side surfaces of the wavelength conversion layer after curing and the transparent plate, and The side surfaces of the wavelength conversion layer and the transparent plate and the outermost peripheries of the mounting regions of the plurality of semiconductor light emitting elements are positioned on substantially the same plane parallel to the optical axis of the semiconductor light emitting element. Is.

  The invention described in claim 8 of the present invention is characterized in that, in claim 6 or 7, both the first binder and the second binder are made of a silicone resin or an epoxy resin. To do.

The invention according to claim 9 of the present invention is the light scattering particle according to any one of claims 6 to 8, wherein the light scattering particles are titanium oxide (TiO ₂ ), zinc oxide (ZnO), boron nitride (B ₂ O ₃ ) and aluminum nitride (AlN).

  The invention described in claim 10 of the present invention is characterized in that, in any of claims 6 to 9, the transparent plate is made of one of glass, silicone resin and epoxy resin. To do.

  In the semiconductor light emitting device of the present invention, a wavelength conversion layer is provided on a growth substrate of a semiconductor light emitting device composed of a growth substrate and an epitaxial growth layer including an active layer, and a transparent plate is further provided on the wavelength conversion layer, and epitaxial growth is performed. A diffuse reflection member was provided so as to integrally cover the side surfaces of the layer, the wavelength conversion layer, and the transparent plate. At this time, the epitaxial growth layer, the wavelength conversion layer, and the transparent plate all have substantially the same outer dimensions in the direction perpendicular to the optical axis of the semiconductor light emitting device, and the respective side surfaces are substantially in the same plane parallel to the optical axis. Located on the top.

  Thereby, from the light emission surface of the transparent plate, which is the light emission surface of the semiconductor light emitting device, it was possible to obtain emission light having uniform chromaticity distribution and luminance distribution over the entire light emission surface.

It is a top view of embodiment concerning the semiconductor light-emitting device of this invention. It is AA sectional drawing of FIG. It is explanatory drawing of the manufacturing process of a semiconductor light-emitting device. It is explanatory drawing of the manufacturing process of a semiconductor light-emitting device. It is a bottom view of a semiconductor light emitting element. It is BB sectional drawing of FIG. It is explanatory drawing of the manufacturing process of a semiconductor light-emitting device. It is explanatory drawing of the manufacturing process of a semiconductor light-emitting device. It is an optical explanatory view of an embodiment (example). It is an optical explanatory view of a conventional example (comparative example). It is explanatory drawing of a prior art example.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 1 to 8 (the same portions are given the same reference numerals). The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. Unless stated to the effect, the present invention is not limited to these embodiments.

  FIG. 1 is a plan view of an embodiment of a semiconductor light emitting device according to the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG.

  The semiconductor light emitting device 1 of the present invention is provided on a semiconductor light emitting element mounting substrate (hereinafter abbreviated as “mounting substrate”) 3 on which a circuit pattern 2 is formed, from the peripheral portion of the mounting substrate 3 along the peripheral portion. An annular side wall 4 having a predetermined height is provided.

  As the mounting substrate, for example, an aluminum nitride (AlN) substrate is used, and for the circuit pattern 2, for example, a gold (Au) plating layer is provided on a copper foil by electrolytic or electroless plating.

  The side wall 4 is made of ceramics, for example.

  A semiconductor light emitting element (hereinafter abbreviated as “light emitting element”) 10 is mounted on the central mounting board 3 in the recess 5 surrounded by the mounting board 3 and the side wall 4. The n-side electrode (bump electrode) 17 and the p-side electrode (bump electrode) 18 of the light emitting element 10 are electrically and mechanically joined. The bump electrodes 17 and 18 are made of a metal material such as gold (Au), for example.

  The light emitting element 10 is manufactured through the steps shown in FIGS.

  First, in the semiconductor growth step shown in FIG. 3A, an n-type semiconductor layer 12, an active layer 13, and a P-type semiconductor layer 14 are sequentially formed on a transparent n-type GaN growth substrate 11 by a crystal growth method such as MOCVD. An epitaxial growth layer 15 having a laminated structure of semiconductor layers is formed by growth, and an epitaxial substrate (hereinafter abbreviated as “epi substrate”) 19 is manufactured. Note that the structures of the crystal growth method, the growth substrate, and the semiconductor layer are not limited to those described above, and known techniques, materials, and layer structures can be used, respectively.

  Next, in the electrode formation step in the element formation step shown in FIG. 3B, an n-side electrode (bump) electrically and mechanically bonded to each of the n-type semiconductor layer 12 and the P-type semiconductor layer 14. Electrodes) 17 and p-side electrodes (bump electrodes) 18 are formed at a plurality of positions at predetermined intervals in the vertical and horizontal directions. Note that, when the bump electrode 17 to be the n-side electrode is formed, regions of the p-type semiconductor layer 14 and the active layer 13 where the bump electrode 17 is formed are removed in advance by etching. Known techniques can be applied to the electrode arrangement, material, and formation method.

  Next, in the growth substrate thinning step of the element forming step shown in FIG. 3C, a wax 28 that is soluble in a solvent with a uniform thickness is applied over the entire surface of the plate-like sample holder 27, The p-type semiconductor layer 14 side of the substrate 19 is bonded and fixed to the sample holder 27 with wax 28. Then, the growth substrate 11 is processed to an appropriate thickness by a method such as grinding and polishing. The thickness of the growth substrate 11 is set in consideration of absorption of light emitted from the active layer 13, mechanical strength, light extraction efficiency of the light emitting element, and the like.

  Next, in the growth substrate end face taper processing step shown in FIG. 3D, the growth substrate 11 is thinned, and the epitaxial substrate 19 on which the bump electrodes 17 and 18 are formed is formed with a tapered cutting edge. By half-cut dicing by the dicing blade 30, the half-cut grooves 31 are formed by dicing in a lattice pattern at predetermined intervals in the vertical and horizontal directions along the thickness direction of the growth substrate 11. A groove having a shape corresponding to the half-cut groove 31 may be formed by a technique such as dry etching instead of dicing.

  Next, in the roughening step of the element forming step shown in FIG. 3E, the surface 20 composed of the upper surface 21 and the side surface 22 of the growth substrate 11 is immersed in an alkaline solution such as a KOH solution for a predetermined time. As a result, the surface having the irregularities 16 is formed by roughening. The size of the concavo-convex 16 is set in consideration of the light extraction efficiency of the light emitting element, the manufacturing yield, and the like.

  Finally, in the singulation step of the elementization step shown in FIG. 3 (f), the cutting edge is fully cut by a straight dicing blade (not shown) along the half-cut groove 31, and thereafter Then, by dissolving the wax with a solvent, a plurality of semiconductor light emitting devices 10 cut into a lattice and separated into pieces are obtained. Alternatively, a method of breaking after scribing with a dicing blade may be used.

Incidentally, in the above step, removal or damage layer by polishing or the like, may be appropriately put the step of forming a protective film of SiO ₂ or the like.

  The light-emitting element 10 manufactured by the above process has an n-type semiconductor on a transparent n-type GaN growth substrate 11 as shown in FIG. 4 (bottom view) and FIG. 5 (BB cross-sectional view in FIG. 4). An epitaxial growth layer 15 having a stacked structure of the layer 12, the active layer 13, and the P-type semiconductor layer 14 is formed, and an n-side electrode (bump electrode) 17 and a p-type semiconductor that are electrically and mechanically joined to the n-type semiconductor layer 12. Each of the p-side electrodes (bump electrodes) 18 electrically and mechanically joined to the layer 14 is provided so as to protrude from the p-type semiconductor layer 14 side.

  In the growth substrate 11, the surface 20 including the upper surface 21 and the side surface 22 is roughened to form a surface having irregularities 16, and the side surface 22 forms an inclined surface inclined at a predetermined angle with respect to the vertical surface of the upper surface 21. doing.

  Referring back to FIGS. 1 and 2, a wavelength conversion layer 40 in which phosphor particles are mixed and dispersed in a binder is formed on the surface 20 including the upper surface 21 and the side surface 22 of the growth substrate 11.

  As the binder constituting the wavelength conversion layer 40, for example, a transparent resin such as a silicone resin or an epoxy resin is preferably used.

  Similarly, the phosphor particles constituting the wavelength conversion layer 40 (hereinafter abbreviated as “phosphor”) are excited by the light emitted from the light emitting element 10 and have a wavelength having a desired wavelength longer than the excitation light. A phosphor that emits converted light is used.

  Specifically, when a blue light emitting element that emits blue light is used as the light emitting element 10, the phosphor constituting the wavelength conversion layer 40 is excited by the blue light from the blue light emitting element to emit complementary light of the blue light. When a yellow phosphor that converts the wavelength into yellow light and emits it is used, the wavelength conversion layer 40 emits part of the direct light of the blue light from the blue light emitting element and the part of the blue light from the blue light emitting element. White light is emitted by additive color mixing with yellow light that has been wavelength-converted by exciting the yellow phosphor in the conversion layer 40.

  Similarly, when a blue light emitting element that emits blue light is used as the light emitting element 10, the phosphor that constitutes the wavelength conversion layer 40 is excited by the blue light from the blue light emitting element and converted into red light and emitted. Using a mixed phosphor of a red phosphor that emits light and a green phosphor that is excited by the blue light from the blue light emitting device and converts the wavelength to green light and emits it, a portion of the blue light from the blue light emitting device is directly emitted In addition, a part of blue light from the blue light-emitting element is caused by additive color mixture of red light and green light that have been wavelength-converted by exciting the phosphors of the red phosphor and the green phosphor in the wavelength conversion layer 40. White light is emitted.

  Furthermore, by appropriately combining the hue (wavelength) of the light emitted from the light emitting element 10 and the type of phosphor, light having various hues different from the emission color of the light emitting element 10 can be obtained.

  A transparent plate 45 for protecting the light emitting element 10 is disposed on the wavelength conversion layer 40. The transparent plate 45 has good light transmittance with respect to the light emitted from the light emitting element 10 and the wavelength converted light by the wavelength conversion layer 40. For example, a transparent inorganic material such as glass, a silicone resin, an epoxy resin, etc. The transparent resin material is used.

  Further, the upper surface (light emitting surface) 46 of the transparent plate 45 is roughened to form an uneven surface with a predetermined roughness. The light emitting surface 46 is roughened by, for example, a chemical method by wet etching using hydrofluoric acid (HF) or the like, or a mechanical method such as sand blasting. The uneven surface formed by roughening may be a regular or geometric shape, or may be a random shape that is neither regular nor geometric.

  The wavelength conversion layer 40 and the transparent plate 45 are in close contact with each other over the entire surface so that no gas such as air is present at the interface contacting each other. Thereby, the loss of light when the light emitted from the light emitting element 10 and incident on the wavelength conversion layer 40 is emitted from the wavelength conversion layer 40 and incident on the transparent plate 45 is suppressed. The transparent plate 45 is made of a material having a refractive index equal to or higher than the refractive index of the binder constituting the wavelength conversion layer 40. Thereby, the light emitted from the wavelength conversion layer 40 is made to enter the transparent plate 45 from the lower surface (light incident surface) 47 of the transparent plate 45 without being totally reflected, and the reduction of the light incident efficiency is suppressed. Has been.

  The light emitting element 10 (epitaxial growth layer 15 of the light emitting element 10), the wavelength conversion layer 40 positioned on the light emitting element 10, and the transparent plate 45 positioned on the wavelength conversion layer 40 are all on the optical axis X of the light emitting element 10. The external dimensions viewed from the direction are substantially the same, and are substantially overlapped with each other when viewed from above the transparent plate 45. That is, the side surface 25 of the epitaxial growth layer 15 including the n-type semiconductor layer 12, the active layer 13, and the p-type semiconductor layer 14, the side surface 25 including the side surface 41 of the wavelength conversion layer 40, and the transparent layer. All the side surfaces 48 of the plate 45 are located on substantially the same plane parallel to the optical axis X.

  A gap between the triple structure formed by the light emitting element 10, the wavelength conversion layer 40, and the transparent plate 45 and the side wall 4 is filled with a diffuse reflection member 50 in which light scattering particles are mixed and dispersed in a binder.

  As the binder constituting the diffuse reflection member 50, for example, a resin such as a silicone resin or an epoxy resin is preferably used.

Similarly, the light scattering particles constituting the diffusive reflecting member 50 are made of metal oxide such as titanium oxide (TiO ₂ ), zinc oxide (ZnO), boron nitride (B ₂ O ₃ ), aluminum nitride (AlN). Is preferred.

  The diffuse reflection member 50 includes a side surface 25 including the side surfaces 12a, 13a, and 14a of the n-type semiconductor layer 12, the active layer 13, and the p-type semiconductor layer 14 of the light emitting element 10, a side surface 41 of the wavelength conversion layer 40, and a transparent plate 45. The side surface 48 of the transparent plate 45 is covered so that it does not cover the light emitting surface 46 of the transparent plate 45 and does not overflow from the side wall 4.

  Next, a method for manufacturing a semiconductor light emitting device will be described with reference to FIGS.

  First, in the light emitting element mounting step shown in FIG. 6A, the mounting substrate 3 on which the circuit pattern 2 is formed and the annular side wall 4 having a predetermined height rising from the peripheral portion of the mounting substrate 3 along the peripheral portion. The light emitting element 10 is mounted on the mounting substrate 3 at the center in the recess 5 of the package 6 made of the above. Here, a semiconductor light-emitting device in which one light-emitting element 10 is mounted in the recess 5 of the package 6 will be described.

  The mounting substrate 3 is an aluminum nitride (AlN) substrate, for example, and the circuit pattern 2 is provided with a gold plating layer on a copper foil by electrolysis or electroless plating, for example. The side wall 4 is made of ceramics, for example.

  In the light emitting element 10, an n-type semiconductor layer 12, an active layer 13, and a P-type semiconductor layer 14 are formed by epitaxial growth on a transparent n-type GaN growth substrate 11, and electrically and mechanically formed on the n-type semiconductor layer 12. Each of an n-side electrode (bump electrode) 17 and a p-side electrode (bump electrode) 18 electrically and mechanically bonded to the p-type semiconductor layer 14 is provided so as to protrude from the p-type semiconductor layer 14 side. Yes. In the growth substrate 11, the surface 20 including the upper surface 21 and the side surface 22 is roughened to form an uneven surface, and the side surface 22 forms an inclined surface that is inclined at a predetermined angle with respect to the vertical surface of the upper surface 21. . The bump electrodes 17 and 18 are made of a metal material such as gold (Au), for example.

  In the light emitting element 10 mounted in the recess 5 of the package 6, the n-side electrode (bump electrode) 17 and the p-side electrode (bump electrode) 18 are electrically and mechanically joined to the circuit pattern 2 of the mounting substrate 3. Yes.

  Next, in the wavelength conversion resin coating step shown in FIG. 6B, a wavelength conversion resin 55 formed by mixing and dispersing phosphor particles in a binder is printed on the upper surface 21 of the growth substrate 11 of the light emitting element 10, for example. Apply a predetermined amount by the method or potting.

  As the binder constituting the wavelength conversion resin 55, for example, a transparent resin such as a silicone resin or an epoxy resin is preferably used.

  Similarly, as the phosphor constituting the wavelength conversion resin 55, a phosphor that is excited by the light emitted from the light emitting element 10 and emits wavelength converted light having a desired wavelength longer than the excitation light is used.

  Specifically, when a blue light-emitting element that emits blue light is used as the light-emitting element 10, the phosphor that constitutes the wavelength conversion resin 55 is excited by blue light from the blue light-emitting element and is used as a complementary color light of blue light. When a yellow phosphor that converts the wavelength into yellow light and emits it is used, the wavelength conversion resin 55 emits a part of the direct light of the blue light from the blue light emitting element and a part of the blue light from the blue light emitting element. By exciting the yellow phosphor in the conversion resin 55, white light is emitted by additive color mixing with the yellow light whose wavelength has been converted.

  Similarly, when a blue light emitting element that emits blue light is used as the light emitting element 10, the phosphor that constitutes the wavelength conversion resin 55 is excited by the blue light from the blue light emitting element and converted into red light and emitted. Using a mixed phosphor of a red phosphor that emits light and a green phosphor that is excited by the blue light from the blue light emitting device and converts the wavelength to green light and emits it, a portion of the blue light from the blue light emitting device is directly emitted In addition, a part of blue light from the blue light-emitting element is caused by additive color mixture of red light and green light that have been wavelength-converted by exciting the phosphors of the red phosphor and the green phosphor in the wavelength conversion resin 55. White light is emitted.

  Furthermore, by appropriately combining the hue (wavelength) of the light emitted from the light emitting element 10 and the type of phosphor, light having various hues different from the emission color of the light emitting element 10 can be obtained.

  Next, in the transparent plate disposing step shown in FIG. 6C, the wavelength conversion resin 55 applied to the upper surface 21 of the growth substrate 11 of the light emitting element 10 is uncured and is placed on the wavelength conversion resin 55. At a position directly above the light emitting element 10, a transparent plate 45 having a substantially same outer dimension as that of the light emitting element 10 in a direction perpendicular to the optical axis of the light emitting element 10 is allowed to stand. The lower surface 47 of the transparent plate 45 and the light emitting element 10 facing each other with the wavelength conversion resin 55 sandwiched between the n-type semiconductor layer 12, the active layer 13 and the p-type semiconductor layer 14. The growth substrate 11 is positioned so as to be parallel to each other and have a predetermined interval.

  At that time, the uncured wavelength conversion resin 55 applied to the upper surface 21 of the growth substrate 11 of the light emitting element 10 is crushed by the pressing movement of the transparent plate 45 and spreads along the lower surface of the transparent plate 45 at the same time. 11 flows down along the side surface 22 formed of an inclined surface. However, the flow is stopped as a resin pool of the wavelength conversion resin 55 in which the side surface 22 of the inclined surface of the growth substrate 11 flows down.

  As a result, the wavelength conversion resin 55 is sandwiched between the entire surface 20 composed of the upper surface 21 and the side surface 22 of the growth substrate 11 and the entire lower surface 47 of the transparent plate 45, and viewed from above the transparent plate 45. 2, the light emitting element 10, the wavelength conversion resin 55 positioned on the light emitting element 10, and the transparent plate 45 positioned on the wavelength conversion resin 55 are positioned so as to substantially overlap each other.

  That is, in the light emitting element 10, the epitaxial growth layer 15 composed of the n type semiconductor layer 12, the active layer 13 and the p type semiconductor layer 14 of the light emitting element 10 composed of the n type semiconductor layer 12, the active layer 13 and the p type semiconductor layer 14. The side surface 25 including the respective side surfaces 12 a, 13 a, and 14 a, the side surface 41 of the wavelength conversion resin 55, and the side surface 48 of the transparent plate 45 are all located on substantially the same plane parallel to the optical axis X of the light emitting element 10. .

  In this state, the uncured wavelength conversion resin 55 is cured under predetermined conditions to form the wavelength conversion layer 40. Thereby, the wavelength conversion layer 40 also has a function as an adhesive layer for fixing the transparent plate 45 to the light emitting element 10.

  The transparent plate 45 has good light transmittance with respect to the light emitted from the light emitting element 10 and the wavelength converted light by the wavelength conversion layer 40. For example, a transparent inorganic material such as glass, a silicone resin, an epoxy resin, etc. The transparent resin material is used.

  Further, the upper surface (light emitting surface) 46 of the transparent plate 45 is roughened to form an uneven surface with a predetermined roughness. The light emitting surface 46 is roughened by, for example, a chemical method by wet etching using hydrofluoric acid (HF) or the like, or a mechanical method such as sand blasting. The uneven surface formed by roughening may be a regular or geometric shape, or may be a random shape that is neither regular nor geometric.

  Finally, in the diffuse reflection member filling step shown in FIG. 6D, light scattering particles are mixed into the binder in the gap between the triple structure formed by the light emitting element 10, the wavelength conversion layer 40, and the transparent plate 45 and the side wall 4. The diffused reflection member 50 formed by dispersion is filled and cured under predetermined conditions.

  As the binder constituting the diffuse reflection member 50, for example, a resin such as a silicone resin or an epoxy resin is preferably used.

Similarly, the light scattering particles constituting the diffusive reflecting member 50 are made of metal oxide such as titanium oxide (TiO ₂ ), zinc oxide (ZnO), boron nitride (B ₂ O ₃ ), aluminum nitride (AlN). Is preferred.

  The diffuse reflection member 50 includes the side surface 25 including the side surfaces 12a, 13a, and 14a of the n-type semiconductor layer 12, the active layer 13, and the p-type semiconductor layer 14, the side surface 41 of the wavelength conversion layer 40, and the transparent plate. The side surface 48 of the transparent plate 45 is covered and the side surface 48 of the transparent plate 45 is covered with the light emitting surface 46 so as not to overflow from the side wall 4.

  Next, the semiconductor light-emitting device having the above structure manufactured by the above-described manufacturing method will be optically described with reference to FIG. 7 (partial cross-sectional view of the semiconductor light-emitting device).

  When power is supplied to the light emitting element 10 from an external power source (not shown) via the circuit pattern 2 and the bump electrodes 17 and 18 on the mounting substrate 3, the active layer 13 of the light emitting element 10 emits light. Of the emitted light (blue light) emitted from the active layer 13, blue light traveling in the direction of the n-type semiconductor layer 12 positioned on the transparent plate 45 side passes through the n-type semiconductor layer 12 and the growth substrate 11 and grows. The light is incident on the wavelength conversion layer 40 from the surface 20 (the main light emitting surface of the light emitting element) composed of the upper surface 21 and the side surface 22 of the light emitting element.

A part of the blue light incident on the wavelength conversion layer 40 is transmitted through the wavelength conversion layer 40 while being part of the blue light B ₁ and enters the transparent plate 45, and a part excites the phosphor (yellow phosphor). Then, the yellow light Y _{1 that} is wavelength-converted and becomes complementary color light of blue light enters the transparent plate 45. Then, each of the blue light B ₁ and the yellow light Y ₁ incident on the transparent plate 45 is transmitted through the transparent plate 45 and diffused and emitted outward from the light emitting surface 46 formed of the uneven surface formed by roughening. is, white diffuse light W ₁ is obtained by additive color mixing of the diffused light emitted consisting of blue diffused light B ₁ and yellow diffused light Y _1.

  On the other hand, of the emitted light (blue light) emitted from the active layer 13, the blue light directed to the side of the active layer 13 has the side surface 13 a of the active layer 13, the light emitting element 10, the wavelength conversion layer 40, and the transparent plate. The blue light reaching the side surface 13a of the active layer 13 covered with the diffuse reflection member 50 filled in the gap between the triple structure 45 and the side wall 4 is the side surface of the active layer 13 of the diffuse reflection member 50. A part of the light is reflected on the contact surface with 13a and the vicinity thereof, and a part thereof is directed to the wavelength conversion layer 40 side.

A part of the blue light traveling toward the wavelength conversion layer 40 is transmitted through the wavelength conversion layer 40 while being part of the blue light B ₂ and enters the transparent plate 45, and a part excites the phosphor (yellow phosphor). The yellow light Y _{2 that} is wavelength-converted and becomes complementary color light of blue light enters the transparent plate 45. Then, each of the blue light B ₂ and the yellow light Y ₂ incident on the transparent plate 45 is transmitted through the transparent plate 45 and diffused and emitted outward from a light emitting surface 46 formed of an uneven surface formed by roughening. is, white diffuse light W ₂ is obtained by additive color mixing of the diffused light emitted consisting of blue diffused light B ₂ and yellow diffused light Y _1.

  As described above, the semiconductor light emitting device (example) of the present embodiment fills the gap between the triple structure of the light emitting element 10, the wavelength conversion layer 40, and the transparent plate 45 and the side wall 4 with the diffuse reflection member 50 to emit light. The device 10 covers the side surface 25 including the side surfaces 12 a, 13 a, and 14 a of the n-type semiconductor layer 12, the active layer 13, and the p-type semiconductor layer 14, the side surface 41 of the wavelength conversion layer 40, and the side surface 48 of the transparent plate 45. I made it.

  As a result, the light emitted from the active layer 13 of the light emitting element 10 and traveling in the light emitting direction of the semiconductor light emitting device 1 (in the direction of the transparent plate 45) constitutes the emitted light of the semiconductor light emitting device 1. The light traveling in the direction also constitutes outgoing light immediately above the light emitting element 10.

  In the comparative example, when the light emitting surface 86 of the transparent plate 84 is viewed from above from above the transparent plate 84, the emitted light is emitted in the region (A) directly above the semiconductor light emitting element 81 located below and the other region (B). There is a difference in hue. That is, when viewed from the top of the semiconductor light emitting device, chromaticity unevenness occurs in the light emitted from the light emitting surface 86 of the transparent plate 84, and the color rendering properties are inferior.

  At the same time, due to the difference in the amount of blue light from the blue semiconductor light emitting element 81 toward the light incident surface 88 of the transparent plate 84, the brightness of the irradiated light is increased in the region (A) immediately above the semiconductor light emitting device 81 and the other region (B). The difference arises. That is, uneven brightness occurs in the emitted light when the semiconductor light emitting device is viewed from above.

  Therefore, the chromaticity unevenness and luminance unevenness are intended to be suppressed by applying a roughening process to the light exit surface 86 of the transparent plate 84 to make the emitted light diffused, but as described above. Since the amount of blue light emitted from the blue semiconductor light emitting element 81 and traveling toward the light incident surface 88 of the transparent plate 84 is different, the effect of suppressing chromaticity unevenness and luminance unevenness must be limited.

  In contrast, in the embodiment, the light emitting element 10, the wavelength conversion layer 40 positioned on the light emitting element 10, and the transparent plate 45 positioned on the wavelength conversion layer 40 are all perpendicular to the optical axis X of the light emitting element 10. The outer dimensions in the same direction are substantially the same, and are substantially overlapping each other when viewed from above the transparent plate 45. That is, the side surface 25 including the side surfaces 12 a, 13 a, and 14 a of the n-type semiconductor layer 12, the active layer 13, and the p-type semiconductor layer 14, the side surface 41 of the wavelength conversion layer 40, and the side surface 48 of the transparent plate 45. Are located on substantially the same plane parallel to the optical axis X.

  Therefore, when the semiconductor light emitting device 1 is viewed from above, each of the chromaticity unevenness and the luminance unevenness is significantly reduced in the emitted light, and the emitted light having a more uniform chromaticity distribution and luminance distribution can be obtained from the entire light emitting surface. .

  Further, in the example, the side surface 22 of the growth substrate 11 of the light emitting element 10 is an inclined surface inclined at a predetermined angle with respect to the vertical surface of the upper surface 21, and this inclined surface is applied to the upper surface 21. When the uncured wavelength conversion resin 55 is crushed by the pressing movement of the transparent plate 45, it functions as a resin pool of the wavelength conversion resin 55 that flows down along the side surface 22 and stops the flow.

  Therefore, the side surface 13 a of the active layer 13 positioned below is prevented from being covered with the wavelength conversion resin 55 and is covered with the diffuse reflection member 50. As a result, the light emitted from the active layer 13 toward the side of the active layer 13 can be reflected by the diffuse reflection member 50 and configured as the emitted light of the semiconductor light emitting device 1. This contributes to improvement in the utilization efficiency of the emitted light.

  Further, if the transparent plate 45 of the example and the transparent plate 84 of the comparative example have the same outer dimensions, the comparative example has a semiconductor light emitting element 81 smaller than the transparent plate 84, and the example has the same size as the transparent plate 45. Since the light emitting element 10 is provided, the embodiment can mount a light emitting element larger than the comparative example. Therefore, when the semiconductor light emitting device 1 is driven (lighted), it can be driven at the same current density as that of the comparative example, and higher brightness than that of the comparative example can be obtained.

  Although the present embodiment is a semiconductor light emitting device in which one light emitting element 10 is mounted in the recess 5 of the package 6, the number of light emitting elements 10 mounted in the package 6 is not limited to one. Alternatively, it is possible to mount a plurality of light emitting elements 10. In that case, the wavelength conversion layer 40 and the transparent plate 45 have the same outer dimensions as the mounting area where the plurality of light emitting elements 10 are mounted, and are disposed immediately above the mounting area of the light emitting elements 10. The side surfaces of the conversion layer and the transparent plate and the outermost circumferences of the mounting regions of the plurality of light emitting elements 10 are located on substantially the same plane parallel to the optical axis of the light emitting elements.

  In addition, it is also possible to use the plate-shaped member provided with wavelength conversion functions, such as fluorescent substance ceramics and fluorescent substance glass, instead of the transparent plate 45 in this embodiment. In that case, it is preferable to use a transparent material layer instead of the wavelength conversion layer 40.

DESCRIPTION OF SYMBOLS 1 ... Semiconductor light-emitting device 2 ... Circuit pattern 3 ... Semiconductor light-emitting device mounting substrate (mounting substrate)
4 ... Side wall 5 ... Recess 6 ... Package 10 ... Semiconductor light emitting device (light emitting device)
DESCRIPTION OF SYMBOLS 11 ... Growth substrate 12 ... N type semiconductor layer 12a ... Side surface 13 ... Active layer 13a ... Side surface 14 ... P type semiconductor layer 14a ... Side surface 15 ... Epitaxial growth layer 16 ... Concavity and convexity 17 ... N side electrode (bump electrode)
18 ... p-side electrode (bump electrode)
19 ... Epitaxial substrate (epi substrate)
20 ... Surface 21 ... Upper surface 22 ... Side surface 25 ... Side surface 27 ... Sample holder 28 ... Wax 30 ... Dicing blade 31 ... Half-cut groove 32 ... Dicing blade 40 ... Wavelength conversion layer 41 ... Side surface 45 ... Transparent plate 46 ... Upper surface (light emission) surface)
47 ... Bottom surface (light incident surface)
48 ... Side 50 ... Diffuse reflection member 55 ... Wavelength conversion resin

Claims (10)

A semiconductor pyramid-shaped growth substrate, and one semiconductor light emitting device having an epitaxial growth layer including an active layer, which is stacked on the bottom surface of the growth substrate;
A wavelength conversion layer provided on the upper surface and side surfaces of the growth substrate, in which phosphor particles are mixed and dispersed in the first binder;
A transparent plate provided on the wavelength conversion layer;
A diffuse reflection member formed by mixing and dispersing light scattering particles in a second binder provided so as to integrally cover the respective sides of the epitaxial growth layer, the wavelength conversion layer, and the transparent plate of the semiconductor light emitting device; With
The epitaxial growth layer, the wavelength conversion layer, and the transparent plate all have substantially the same outer dimensions in the direction perpendicular to the optical axis of the semiconductor light emitting device, and the respective side surfaces are substantially parallel to the optical axis. A semiconductor light emitting device which is located on the same plane. A plurality of semiconductor light emitting devices having a growth substrate having a truncated pyramid shape and an epitaxial growth layer including an active layer, which is stacked on a bottom surface of the growth substrate;
A wavelength conversion layer in which phosphor particles are mixed and dispersed in a first binder, which are integrally provided on an upper surface and a side surface of each growth substrate of the plurality of semiconductor light emitting elements;
A transparent plate provided on the wavelength conversion layer;
Light scattering particles are mixed and dispersed in a second binder provided so as to integrally cover each of the epitaxial growth layers, the wavelength conversion layers, and the transparent plates of the plurality of semiconductor light emitting devices. And a diffuse reflection member
The wavelength conversion layer and the transparent plate have substantially the same outer dimensions as mounting regions of the plurality of semiconductor light emitting elements, and each side surface of the wavelength conversion layer and the transparent plate and the plurality of semiconductor light emitting elements. The outermost peripheries of the mounting regions are positioned on substantially the same plane parallel to the optical axis of the semiconductor light emitting element.   3. The semiconductor light emitting device according to claim 1, wherein each of the first binder and the second binder is made of a silicone resin or an epoxy resin. The light scattering particle is made of one of titanium oxide (TiO ₂ ), zinc oxide (ZnO), boron nitride (B ₂ O ₃ ), and aluminum nitride (AlN). 4. The semiconductor light emitting device according to any one of items 3.   The semiconductor light-emitting device according to claim 1, wherein the transparent plate is made of one of glass, silicone resin, and epoxy resin. Phosphor particles in a first binder on the top surface of the growth substrate of one semiconductor light emitting device having a growth substrate having a truncated pyramid shape and an epitaxial growth layer including an active layer stacked on the bottom surface of the growth substrate A step of applying a wavelength conversion resin in which is mixed and dispersed,
In the uncured state of the wavelength conversion resin, the wavelength conversion resin is crushed by pressing and moving the wavelength conversion resin to the epitaxial growth layer side with a transparent plate having substantially the same outer dimensions as the epitaxial growth layer. Covering the upper surface and the side surface by flowing down from the upper surface to the side surface;
A diffuse reflection member is formed by mixing and dispersing light scattering particles in the second binder so as to integrally cover the epitaxial growth layer, the wavelength conversion layer after curing of the wavelength conversion resin, and the side surfaces of the transparent plate. And having a process
A method of manufacturing a semiconductor light emitting device, wherein the side surfaces of the epitaxial growth layer, the wavelength conversion layer, and the transparent plate are positioned on substantially the same plane parallel to the optical axis of the semiconductor light emitting element. A plurality of semiconductor light emitting devices each having a rectangular pyramid-shaped growth substrate and an epitaxial growth layer including an active layer stacked on the bottom surface of the growth substrate so as to cover the upper surface of the growth substrate. Applying a wavelength conversion resin in which phosphor particles are mixed and dispersed in the first binder;
When the wavelength conversion resin is in an uncured state, each of the wavelength conversion resins is pressed by moving collectively to the epitaxial growth layer side with a transparent plate having substantially the same outer dimensions as the mounting area of the plurality of semiconductor light emitting elements. Each of the crushed wavelength conversion resins flows down from the upper surface of the growth substrate to the side surface and integrally covers the upper surface and the side surface of each growth substrate;
Light scattering particles are mixed in the second binder so as to integrally cover the respective epitaxial growth layers of the plurality of semiconductor light emitting elements, the wavelength conversion layers after curing of the wavelength conversion resin, and the side surfaces of the transparent plate. A step of providing a diffuse reflection member formed by dispersion,
The side surfaces of the wavelength conversion layer and the transparent plate and the outermost peripheries of the mounting regions of the plurality of semiconductor light emitting elements are positioned on substantially the same plane parallel to the optical axis of the semiconductor light emitting element. A method for manufacturing a semiconductor light emitting device.   The method for manufacturing a semiconductor light-emitting device according to claim 6, wherein each of the first binder and the second binder is made of a silicone resin or an epoxy resin. The light scattering particle is made of one of titanium oxide (TiO ₂ ), zinc oxide (ZnO), boron nitride (B ₂ O ₃ ), and aluminum nitride (AlN). Item 9. A method for manufacturing a semiconductor light-emitting device according to any one of Items 8 to 10.   The method for manufacturing a semiconductor light emitting device according to claim 6, wherein the transparent plate is made of one of glass, silicone resin, and epoxy resin.

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