JP2019134150A - Light emitting device - Google Patents

Abstract

To provide a light emitting device capable of suppressing color non-uniformity of distributed light.SOLUTION: A light emitting device includes: a light emitting element having a first surface and a second surface located on the opposite side of the first surface; a light guide member covering a lateral surface of the light emitting element; a first wavelength conversion member which covers the first surface and includes a first matrix and first wavelength conversion particles; and a reflective member which covers the lateral surface of the light emitting element, a lateral surface of the light guide member and a lateral surface of the first wavelength conversion member, the reflective member being in contact with the light emitting element. The first wavelength conversion member has a thickness of 60 μm or more an 120 μm or less. The first wavelength conversion particles have an average particle size of 4 μm or more and 12 μm or less. The first wavelength conversion particles have a central particle size of 4 μm or more and 12 μm or less. A weight ratio of the first wavelength conversion particles is 60 wt.% or more and 75 wt.% or less with respect to the total weight of the first wavelength conversion member.SELECTED DRAWING: Figure 2A

Description

  The present invention relates to a light emitting device.

  A light-emitting element, an optical layer disposed on the light-emitting element that transmits at least part of the light emitted from the light-emitting element, and a plate-like element that is mounted on the optical layer and transmits at least part of the light emitted from the light-emitting element A light-emitting device having an optical member is known (see, for example, Patent Document 1).

JP 2012-134355 A

  When used as a backlight or illumination, a light emitting device capable of obtaining light of uniform chromaticity regardless of location is required. Accordingly, an object of the embodiment according to the present invention is to provide a light emitting device capable of suppressing light distribution chromaticity unevenness.

  A light-emitting device according to one embodiment of the present invention includes a light-emitting element having a first surface and a second surface located on the opposite side of the first surface, a light guide member that covers a side surface of the light-emitting element, A first wavelength conversion member that covers the first surface and includes a first base material and first wavelength conversion particles, a side surface of the light emitting element, a side surface of the light guide member, and a side surface of the first wavelength conversion member. A reflective member in contact with the light emitting element, the thickness of the first wavelength conversion member is 60 μm or more and 120 μm or less, and the average particle diameter of the first wavelength conversion particles is 4 μm or more and 12 μm or less, The center particle diameter of the first wavelength conversion particles is 4 μm or more and 12 μm or less, and the first wavelength conversion particles are 60 wt% or more and 75 wt% or less with respect to the total weight of the first wavelength conversion member.

  According to the light emitting device of the embodiment according to the present invention, it is possible to provide a light emitting device capable of suppressing light distribution chromaticity unevenness.

1A is a schematic perspective view of a light-emitting device according to Embodiment 1. FIG. 1B is a schematic perspective view of the light emitting device according to Embodiment 1. FIG. 1C is a schematic front view of the light emitting device according to Embodiment 1. FIG. 2A is a schematic cross-sectional view taken along line 2A-2A in FIG. 1C. 2B is a schematic cross-sectional view taken along line 2B-2B in FIG. 1C. FIG. 2C is a schematic cross-sectional view of a modified example of the light-emitting device according to Embodiment 1. FIG. 2D is a schematic cross-sectional view of a modification of the light-emitting device according to Embodiment 1. FIG. 3A is a schematic rear view of the light emitting device according to the first embodiment. 3B is a schematic bottom view of the light emitting device according to Embodiment 1. FIG. 3C is a schematic side view of the light-emitting device according to Embodiment 1. FIG. FIG. 4 is a schematic side view of the substrate according to the first embodiment. FIG. 5A is a schematic cross-sectional view of the light-emitting device according to Embodiment 1, and an enlarged view showing the inside of a dotted line part in an enlarged manner. FIG. 5B is a schematic cross-sectional view of a modified example of the light emitting device according to Embodiment 1, and an enlarged view showing the inside of a dotted line part in an enlarged manner.

  Embodiments of the invention will be described below with reference to the drawings as appropriate. However, the light-emitting device described below is for embodying the technical idea of the present invention, and the present invention is not limited to the following unless otherwise specified. The contents described in one embodiment can be applied to a modification. Furthermore, the size, positional relationship, and the like of the members illustrated in the drawings may be exaggerated for clarity of explanation.

<Embodiment 1>
A light emitting device 1000 according to an embodiment of the present invention will be described with reference to FIGS. 1A to 5B. The light emitting device 1000 includes the light emitting element 20, the light guide member 50, the first wavelength conversion member 31, and the reflection member 40. The light emitting element 20 has a first surface 201 and a second surface 203 located on the opposite side of the first surface 201. The light guide member 50 covers the side surface 202 of the light emitting element. The first wavelength conversion member 31 covers the first surface 201 of the light emitting element. The first wavelength conversion member 31 includes a first base material 312 and first wavelength conversion particles 311. The thickness of the first wavelength conversion member 31 is 60 μm or more and 120 μm or less. The average particle diameter of the first wavelength conversion particles 311 is 4 μm or more and 12 μm or less. The center particle diameter of the first wavelength conversion particles 311 is 4 μm or more and 12 μm or less. The first wavelength conversion particles 311 are 60 wt% or more and 75 wt% or less with respect to the total weight of the first wavelength conversion member 31. The reflection member 40 covers the side surface of the light emitting element, the side surface of the light guide member, and the side surface of the first wavelength conversion member. The reflective member 40 is in contact with the light emitting element. The light emitting device may include at least one light emitting element. That is, the light emitting device may include only one light emitting element, or may include a plurality of light emitting elements.

  The average particle diameter of the first wavelength conversion particles 311 included in the first wavelength conversion member 31 is 4 μm or more and 12 μm or less. When the average wavelength of the first wavelength conversion particles 311 is 12 μm or less, the first base material 312 and the first wavelength are obtained when the concentration of the first wavelength conversion particles 311 included in the first wavelength conversion member 31 is the same. The interface with the conversion particles 311 can be increased. By increasing the interface between the first base material and the first wavelength conversion particles, the light from the light emitting element is easily diffused by the interface between the first base material and the first wavelength conversion particles. Thereby, since the light from a light emitting element is diffused in the 1st wavelength conversion member, the light distribution chromaticity nonuniformity of a light-emitting device can be suppressed. When the average particle diameter of the first wavelength conversion particles is 4 μm or more, the light extraction efficiency of the light emitting device is improved because the light from the light emitting element is easily extracted.

  In this specification, the average particle diameter of the first wavelength conversion particles 311 is an average value of particle diameters measured by the FSSS method (Fisher Sub-Sieve Sizer). The average particle size measured by the Fischer method is measured using, for example, Fisher Sub-Sieve Sizer Model 95 (manufactured by Fisher Scientific).

  The center wavelength of the first wavelength conversion particles 311 included in the first wavelength conversion member 31 is 4 μm or more and 12 μm or less. When the central particle diameter of the first wavelength conversion particles is 12 μm or less, the first base material and the first wavelength conversion particles are obtained when the concentration of the first wavelength conversion particles 311 included in the first wavelength conversion member 31 is the same. And the interface increases. By increasing the interface between the first base material and the first wavelength conversion particles, the light from the light emitting element is easily diffused by the interface between the first base material and the first wavelength conversion particles. Thereby, since the light from a light emitting element is diffused in the 1st wavelength conversion member, the light distribution chromaticity nonuniformity of a light-emitting device can be suppressed. When the center wavelength of the first wavelength conversion particles is 4 μm or more, light from the light emitting element can be easily extracted, so that the light extraction efficiency of the light emitting device is improved.

  In this specification, the center particle diameter of the first wavelength conversion particle 311 is a volume average particle diameter (median diameter), and a particle diameter (D50: median diameter) at which the volume cumulative frequency from the small diameter side reaches 50%. That is. The central particle size can be measured with a laser diffraction particle size distribution measuring device (MASTER SIZER 2000 manufactured by MALVERN).

  The particle diameter (D10) at which the volume cumulative frequency from the small diameter side of the first wavelength conversion particles reaches 10% is preferably 6 μm or more and 10 μm or less. The particle diameter (D90) at which the volume cumulative frequency from the small diameter side of the first wavelength conversion particles reaches 90% is preferably 15 μm or more and 20 μm or less.

  The standard deviation (σlog) of the particle size distribution on the volume basis of the first wavelength conversion particles is preferably 0.3 μm or less. The formation of the wavelength conversion member 31 having a uniform thickness is facilitated by the small variation in the first wavelength conversion particles.

  Examples of the first wavelength conversion particles include manganese-activated fluoride phosphors. Manganese-activated fluoride phosphors are preferable members from the viewpoint of color reproducibility because they can emit light with a relatively narrow spectral line width.

  The thickness of the first wavelength conversion member 31 is 60 μm or more and 120 μm or less. When the thickness of the first wavelength conversion member is 60 μm or more, the first wavelength conversion particles 311 that can be contained in the first wavelength conversion member 31 can be increased. When the thickness of the first wavelength conversion member 31 is 120 μm or less, the light emitting device can be thinned. The thickness of the first wavelength conversion member is the thickness of the first wavelength conversion member in the Z direction.

  The first wavelength conversion particles 311 are 60 wt% or more and 75 wt% or less with respect to the total weight of the first wavelength conversion member 31. Since the content of the first wavelength conversion particles increases when the first wavelength conversion particles are 60% by weight or more based on the total weight of the first wavelength conversion member, the first base material and the first wavelength conversion particles And the interface increases. By increasing the interface between the first base material and the first wavelength conversion particles, the light from the light emitting element is easily diffused by the interface between the first base material and the first wavelength conversion particles. Thereby, since the light from a light emitting element is diffused in the 1st wavelength conversion member, the light distribution chromaticity nonuniformity of a light-emitting device can be suppressed. Since the ratio of the 1st base material in the 1st wavelength conversion member increases because the 1st wavelength conversion particle is 75 weight% or less with respect to the total weight of the 1st wavelength conversion member, the 1st wavelength conversion member Breaking can be suppressed. The first wavelength conversion member may have only the first wavelength conversion particles as the wavelength conversion particles, or may have wavelength conversion particles made of a material different from the first wavelength conversion particles.

  The light-emitting device may include a second wavelength conversion member 32 positioned between the light-emitting element 20 and the first wavelength conversion member 31 as in the light-emitting device 1000 illustrated in FIG. 2A, and the light-emitting device 1000A illustrated in FIG. 2C. As described above, the second wavelength conversion member positioned between the light emitting element 20 and the first wavelength conversion member 31 may not be provided. The second wavelength conversion member 32 includes a second base material 322 and second wavelength conversion particles 321. The average particle diameter of the first wavelength conversion particles 311 is preferably smaller than the average particle diameter of the second wavelength conversion particles 321. Since the average particle diameter of the second wavelength conversion particles is larger than the average particle diameter of the first wavelength conversion particles, the light from the light emitting element is easily guided to the second wavelength conversion member 32. Will improve. Further, since the average particle diameter of the first wavelength conversion particles 311 is smaller than the average particle diameter of the second wavelength conversion particles 321, light from the light emitting element is easily diffused in the first wavelength conversion member 31, and the light emitting device The light distribution chromaticity unevenness can be suppressed. The material of the first wavelength conversion particles and the material of the second wavelength conversion particles may be the same or different. Further, the material of the first base material 312 and the material of the second base material 322 may be the same or different. Since the material of the first base material 312 and the material of the second base material 322 are the same, the bonding strength between the first wavelength conversion member 31 and the 22nd wavelength conversion member 32 is improved. Due to the difference between the material of the first base material 312 and the material of the second base material 322, a difference in refractive index occurs between the first base material 312 and the second base material 322. Accordingly, light from the light emitting element is easily diffused at the interface between the first base material 312 and the second base material 322, so that uneven light distribution chromaticity of the light emitting device can be suppressed. The refractive index of the first base material 312 is preferably higher than the refractive index of the second base material 322. By doing in this way, it can control that the light from a light emitting element totally reflects in the interface of the 1st base material 312 and the 2nd base material 322. Thereby, the light extraction efficiency of the light emitting device is improved.

  The thickness of the second wavelength conversion member 32 is preferably 20 μm or more and 60 μm or less. When the thickness of the second wavelength conversion member 32 is 20 μm or more, the second wavelength conversion particles 321 that can be contained in the second wavelength conversion member 32 can be increased. When the thickness of the second wavelength conversion member 32 is 60 μm or less, the light emitting device can be thinned. The thickness of the second wavelength conversion member is the thickness of the second wavelength conversion member in the Z direction.

  The thickness of the second wavelength conversion member 32 is preferably half or less than the thickness of the first wavelength conversion member 31. By doing in this way, the light from a light emitting element becomes easier to be irradiated to the 1st wavelength conversion member 31 than the case where the 2nd wavelength conversion member 32 is thick. For example, when the first wavelength conversion member 31 is 80 ± 5 μm, the thickness of the second wavelength conversion member 32 is preferably 35 ± 5 μm. In addition, the thickness of the covering member 33 that covers the first wavelength conversion member 31 described later may have the same thickness as that of the first wavelength conversion member 31. For example, the thickness of the first wavelength conversion member 31 may be 80 ± 5 μm, the thickness of the second wavelength conversion member 32 may be 35 ± 5 μm, and the thickness of the covering member 33 may be 80 ± 5 μm. In the present specification, the equivalent thickness means that a fluctuation of about 5 μm is allowed.

  The peak wavelength of light from the second wavelength conversion particle 321 excited by the light emitting element is preferably shorter than the peak wavelength of light from the first wavelength conversion particle 311 excited by the light emitting element. The peak wavelength of the light from the second wavelength conversion particle 321 excited by the light emitting element is shorter than the peak wavelength of the light from the first wavelength conversion particle 311 excited by the light emitting element, thereby being excited by the light emitting element. The first wavelength conversion particles can be excited by light from the second wavelength conversion particles. Thereby, the light from the excited first wavelength conversion particles can be increased. Since the first wavelength conversion member 31 is disposed on the second wavelength conversion member 32, the light from the second wavelength conversion particles excited by the light emitting element is easily emitted to the first wavelength conversion particles.

  The peak wavelength of light from the first wavelength conversion particle 311 excited by the light emitting element is 610 nm or more and 750 nm or less, and the peak wavelength of light from the second wavelength conversion particle 321 excited by the light emitting element is 500 nm or more and 570 nm or less. Preferably there is. By doing in this way, it can be set as the light-emitting device with high color rendering property. A light emitting element (blue light emitting element) having an emission peak wavelength in a range from 430 nm to 475 nm, a first wavelength conversion particle having a peak wavelength of light from 610 nm to 750 nm after being excited by the light emitting element, excited to the light emitting element By combining with the second wavelength conversion particles having a peak wavelength of the light from 500 nm or more and 570 nm or less, a white light emitting device can be obtained. For example, a manganese-activated potassium fluorosilicate phosphor is exemplified as the first wavelength conversion particle, and a β sialon-based phosphor is exemplified as the second wavelength conversion particle. In the case of using a manganese-activated potassium fluorosilicate phosphor as the first wavelength conversion particle, it is particularly preferable to include a second wavelength conversion member 32 positioned between the light emitting element 20 and the first wavelength conversion member 31. . The first wavelength conversion particles, which are manganese-activated fluoride phosphors, are likely to cause luminance saturation. However, the second wavelength conversion member 32 is positioned between the first wavelength conversion member 31 and the light emitting element 20, so that the first wavelength conversion particle is emitted from the light emitting element. It can suppress that light is irradiated to the 1st wavelength conversion particle too much. Thereby, degradation of the 1st wavelength conversion particle which is manganese activation fluoride fluorescent substance can be suppressed.

  As shown in FIG. 2A, the light emitting element 20 includes a first surface 201 and a second surface 203 opposite to the first surface 201. The light emitting element 20 includes at least a semiconductor laminate 23, and the semiconductor laminate 23 is provided with positive and negative electrodes 21 and 22. The positive and negative electrodes 21 and 22 are formed on the same surface of the light emitting element 20, and the light emitting element 20 is preferably flip-chip mounted on the mounting substrate. This eliminates the need for a wire for supplying electricity to the positive and negative electrodes of the light emitting element, thereby reducing the size of the light emitting device. When the light emitting element is flip-chip mounted, the positive and negative electrodes 21 and 22 of the light emitting element are positioned on the second surface 203. In the present embodiment, the light emitting element 20 includes the element substrate 24, but the element substrate 24 may be removed.

  The light guide member 50 covers the side surface 202 of the light emitting element. The light guide member 50 has a higher light transmittance from the light emitting element 20 than the reflective member 40. For this reason, since the light guide member 50 covers the side surface 202 of the light emitting element, the light emitted from the side surface of the light emitting element 20 can be easily extracted to the outside of the light emitting device through the light guide member 50, thereby increasing the light extraction efficiency. be able to. The light guide member 50 may be positioned between the first surface 201 of the light emitting element and the translucent member 30, and is positioned between the first surface 201 of the light emitting element and the translucent member 30. It does not have to be. Since the light guide member is a member that bonds the light emitting element and the translucent member, the light guide member is positioned between the first surface 201 of the light emitting element and the translucent member 30, so The bonding strength of the optical member is improved.

  The reflection member 40 covers the side surface of the light emitting element, the side surface of the light guide member, and the side surface of the first wavelength conversion member. Thus, a light-emitting device with high contrast between the light-emitting region and the non-light-emitting region and excellent “parting ability” can be obtained. Further, at least a part of the reflecting member 40 is in contact with the light emitting element. The light-emitting device can be reduced in size by at least part of the reflecting member 40 being in contact with the light-emitting element. The reflecting member 40 is preferably in contact with the second surface 203 of the light emitting element. By doing in this way, it can suppress that the light from a light emitting element is absorbed by the board | substrate which mounts a light emitting element.

  As in the light emitting device 1000 illustrated in FIG. 2A, a covering member 33 that covers the first wavelength conversion member 31 may be provided. The covering member 33 does not substantially contain wavelength conversion particles. By providing the covering member 33 that covers the first wavelength converting member 31, the covering member 33 functions as a protective layer even if the first wavelength converting particles that are weak against moisture are used. Can be suppressed. Examples of the wavelength conversion particles that are vulnerable to moisture include manganese-activated fluoride phosphors. Manganese-activated fluoride phosphors are preferable members from the viewpoint of color reproducibility because they can emit light with a relatively narrow spectral line width. “Substantially free of wavelength conversion particles” means that wavelength conversion particles inevitably mixed are not excluded, and the content of the wavelength conversion particles is preferably 0.05% by weight or less. In the present specification, the first wavelength conversion member 31, the second wavelength conversion member 32, and / or the covering member 33 may be collectively referred to as a translucent member 30.

  Like the light emitting device 1000 </ b> C illustrated in FIG. 2D, a film 34 that covers the upper surface of the translucent member 30 may be provided. The coating 34 is an aggregate of coating particles that are nanoparticles. Note that the coating may be only coating particles or may include coating particles and a resin material. Since the refractive index of the coating is different from the refractive index of the base material of the translucent member located on the outermost surface, the emission chromaticity of the light emitting device can be corrected. The base material of the translucent member located on the outermost surface means a base material of a layer that forms a surface of the translucent member opposite to the surface on the light extraction surface side of the light emitting element. For example, when the refractive index of the coating 34 is larger than the refractive index of the base material of the translucent member located on the outermost surface, the reflected light component at the interface between the coating and the air is less than that of the translucent member located on the outermost surface. It increases more than the reflected light component at the interface between the base material and air. For this reason, since the reflected light component which returns in a translucent member can be increased, it becomes easy to excite the wavelength conversion particle. Thereby, the light emission chromaticity of the light emitting device can be corrected to the long wavelength side. When the refractive index of the coating 34 is smaller than the refractive index of the base material of the translucent member located on the outermost surface, the reflected light component at the interface between the coating and air is the interface between the base material of the translucent member and the air. This is less than the reflected light component at. Thereby, since the reflected light component which returns in a translucent member can be reduced, it becomes difficult to excite the wavelength conversion particle. Thereby, the light emission chromaticity of the light emitting device can be corrected to the short wavelength side. For example, when a phenyl silicone resin is used as the base material of the translucent member located on the outermost surface, titanium oxide, titanium oxide, aluminum oxide, etc. are used as coating particles for correcting the light emission chromaticity of the light emitting device to the long wavelength side. Is mentioned. When the base material of the translucent member located on the outermost surface uses a phenyl silicone resin, silicon oxide or the like can be used as the coating particle that corrects the emission chromaticity of the light emitting device to the short wavelength side. In the case where the light-emitting device includes a plurality of light-transmitting members, the upper surface of one light-transmitting member may be covered with a film, and the upper surface of the other light-transmitting member may not be covered with a film. Whether to form a film covering the upper surface of the translucent member in accordance with the correction of the light emission chromaticity of the light emitting device can be appropriately selected. In the case where the light emitting device includes a plurality of translucent members, the upper surface of one translucent member is covered with a film having a refractive index larger than that of the base material of the translucent member located on the outermost surface. The upper surface of the other translucent member may be covered with a film having a refractive index smaller than that of the base material of the translucent member located on the outermost surface. The material of the film that covers the translucent member can be appropriately selected in accordance with the correction of the light emission chromaticity of the light emitting device. The coating can be formed by a known method such as potting with a dispenser, spraying with an ink jet or spray.

  The light emitting device may include a substrate 10 on which the light emitting element is placed. For example, the substrate 10 includes a base material 11, a first wiring 12, a second wiring 13, a third wiring 14, and a via 15. The base material 11 includes a front surface 111 extending in a first direction that is a longitudinal direction and a second direction that is a short direction, a back surface 112 positioned on the opposite side of the front surface, and a bottom surface that is adjacent to the front surface 111 and orthogonal to the front surface 111. 113 and a top surface 114 located on the opposite side of the bottom surface 113. The substrate 11 further has at least one recess 16. The first wiring 12 is disposed on the front surface 111 of the base material 11. The second wiring 13 is disposed on the back surface 112 of the base material 11. The light emitting element 20 is electrically connected to the first wiring 12 and placed on the first wiring 12. The reflecting member 40 covers the side surface 202 of the light emitting element 20 and the front surface 111 of the substrate. At least one recess opens in the back surface 112 and the bottom surface 113. The third wiring 14 covers the inner wall of the recess and is electrically connected to the second wiring. The via 15 is in contact with the first wiring 12 and the second wiring. The via 15 electrically connects the first wiring 12 and the second wiring 13. Further, the via 15 penetrates from the front surface 111 to the back surface 112 of the base material 11. In the present specification, “orthogonal” means that an inclination of about 90 ° to ± 3 ° is allowed.

  The via 15 may be in contact with the third wiring, and the via 15 may be separated from the third wiring. Since the via 15 is in contact with the third wiring, heat from the light emitting element can be transmitted from the first wiring 12 to the second wiring 13 and / or the third wiring 14 via the via 15. The heat dissipation can be improved. By separating the via 15 from the third wiring, the via and the recess do not overlap in the rear view, so that the strength of the substrate is improved. When there are a plurality of vias 15, one via may be in contact with the third wiring and the other via may be separated from the third wiring.

  When the light emitting element 20 is flip-chip mounted on the substrate 10, the positive and negative electrodes 21 and 22 of the light emitting element are connected to the substrate 10 through the conductive adhesive member 60. When the light emitting element 20 is flip-chip mounted on the substrate 10, it is preferable that the first wiring 12 includes a convex portion 121. When the positive and negative electrodes 21 and 22 of the light emitting element 20 are positioned on the convex portion 121 of the first wiring 12, the first wiring 12 and the positive and negative electrodes 21 and 22 of the light emitting element are connected via the conductive adhesive member 60. The alignment between the light emitting element and the substrate can be easily performed by the self-alignment effect.

  The via 15 is preferably circular in rear view. By doing in this way, it can form easily with a drill etc. In this specification, the circular shape includes not only a perfect circle but also a shape close to this (for example, an elliptical shape or a shape in which four corners of a quadrangle are chamfered in a large arc shape).

  The via 15 may be configured by filling the through hole of the base material with a conductive material. As illustrated in FIG. 2A, the fourth wiring 151 and the fourth wiring covering the surface of the through hole of the base material. A filling member 152 filled in a region surrounded by the wiring 151 may be provided. The filling member 152 may be conductive or insulating. It is preferable to use a resin material for the filling member 152. In general, the resin material before curing has a higher fluidity than the metal material before curing, so that the fourth wiring 151 is easily filled. For this reason, manufacture of a board | substrate becomes easy by using a resin material for a filling member. Examples of the resin material that can be easily filled include an epoxy resin. When using a resin material as the filling member, it is preferable to contain an additive member in order to lower the linear expansion coefficient. By doing in this way, since the difference of the linear expansion coefficient with 4th wiring becomes small, it can suppress that a clearance gap is made between 4th wiring and a filling member with the heat | fever from a light emitting element. Examples of the additive member include silicon oxide. In addition, when a metal material is used for the filling member 152, heat dissipation can be improved. In addition, when the via 15 is configured by filling the through hole of the base material with a conductive material, it is preferable to use a metal material such as Ag or Cu having high thermal conductivity.

  The light emitting device 1000 can be fixed to the mounting substrate by a joining member such as solder formed in the recess 16. The number of depressions provided in the substrate may be one or plural. By having a plurality of depressions, the bonding strength between the light emitting device 1000 and the mounting substrate can be improved. The depth of the depression may be the same depth on the upper surface side and the bottom surface side, or may be deeper on the bottom surface side than the upper surface side. As shown in FIG. 2B, since the depth of the depression 16 in the Z direction is deeper on the bottom surface side than the upper surface side, the thickness W1 of the base material located on the upper surface side of the depression is positioned on the bottom surface side of the depression in the Z direction. It can be made thicker than the thickness W2 of the substrate. Thereby, the strength reduction of a base material can be suppressed. Further, since the depth W3 of the recess on the bottom surface side is deeper than the depth W4 of the recess on the upper surface side, the volume of the bonding member formed in the recess increases, so that the bonding strength between the light emitting device 1000 and the mounting substrate is increased. Can be improved. Even if the light emitting device 1000 is a top emission type (top view type) in which the back surface 112 of the base material 11 and the mounting substrate are mounted to face each other, the bottom surface 113 of the base material 11 and the mounting substrate are mounted to face each other. Even in the side light emission type (side view type), the bonding strength with the mounting substrate can be improved by increasing the volume of the bonding member.

  The bonding strength between the light emitting device 1000 and the mounting substrate can be improved particularly in the case of the side light emitting type. Since the depth of the recess in the Z direction is deeper on the bottom surface side than the upper surface side, the area of the opening of the recess on the bottom surface can be increased. By increasing the area of the opening of the depression on the bottom surface facing the mounting substrate, the area of the bonding member located on the bottom surface can also be increased. Thereby, since the area of the bonding member positioned on the surface facing the mounting substrate can be increased, the bonding strength between the light emitting device 1000 and the mounting substrate can be improved.

  The maximum depth of the recess in the Z direction is preferably 0.4 to 0.9 times the thickness of the base material in the Z direction. When the depth of the recess is deeper than 0.4 times the thickness of the base material, the volume of the bonding member formed in the recess is increased, so that the bonding strength between the light emitting device and the mounting substrate can be improved. When the depth of the dent is shallower than 0.9 times the thickness of the base material, it is possible to suppress the strength reduction of the base material.

  As shown in FIG. 2B, the recess 16 preferably includes a parallel portion 161 extending from the back surface 112 in a direction parallel to the bottom surface 113 (Z direction). By providing the parallel part 161, even if the area of the opening part of the dent on the back surface is the same, the volume of the dent can be increased. By increasing the volume of the recess, the amount of bonding members such as solder that can be formed in the recess can be increased, so that the bonding strength between the light emitting device 1000 and the mounting substrate can be improved. In the present specification, “parallel” means that an inclination of about ± 3 ° is allowed. In addition, the recess 16 includes an inclined portion 162 that is inclined from the bottom surface 113 in a direction in which the thickness of the base material 11 is increased in a cross-sectional view. The inclined portion 162 may be straight or curved.

  The maximum height of the recess in the Y direction is preferably 0.3 to 0.75 times the thickness of the base material in the Y direction. Since the depth of the recess in the Y direction is longer than 0.3 times the thickness of the base material, the volume of the bonding member formed in the recess increases, so that the bonding strength between the light emitting device and the mounting substrate can be improved. it can. When the length of the dent in the Y direction is shallower than 0.75 times the thickness of the base material, a decrease in the strength of the base material can be suppressed.

  As shown in FIG. 3A, in the case where there are a plurality of recesses 16 on the back surface, it is preferable that they are positioned symmetrically with respect to the center line 3C of the base material parallel to the Y direction. By doing so, self-alignment effectively works when the light emitting device is mounted on the mounting substrate via the bonding member, and the light emitting device can be mounted with high accuracy within the mounting range.

  The light emitting device may include an insulating film 18 that covers a part of the second wiring 13. By providing the insulating film 18, it is possible to ensure insulation on the back surface and prevent a short circuit. Moreover, it can prevent that the 2nd wiring peels from a base material.

  On the bottom surface, the depth of the recess in the Z direction may be substantially constant, and the depth of the recess may be different between the center and the end. As shown in FIG. 3B, the depth D1 at the center of the recess 16 is preferably the maximum depth of the recess in the Z direction on the bottom surface. By doing in this way, in the bottom face, the base material thickness D2 in the Z direction can be increased at the end of the recess in the X direction, so that the strength of the base material can be improved. In the present specification, the center means that a fluctuation of about 5 μm is allowed. The depression 16 can be formed by a known method such as a drill or a laser.

  As shown in FIG. 3C, the side surface 403 in the longitudinal direction of the reflecting member 40 located on the bottom surface 113 side is preferably inclined inward of the light emitting device 1000 in the Z direction. Thus, when the light emitting device 1000 is mounted on the mounting substrate, the contact between the side surface 403 of the reflecting member 40 and the mounting substrate is suppressed, and the mounting posture of the light emitting device 1000 is easily stabilized. The side surface 404 in the longitudinal direction of the reflecting member 40 located on the upper surface 114 side is preferably inclined inward of the light emitting device 1000 in the Z direction. By doing so, the contact between the side surface of the reflecting member 40 and the suction nozzle (collet) can be suppressed, and damage to the reflecting member 40 during the suction of the light emitting device 1000 can be suppressed. As described above, the longitudinal side surface 403 of the reflecting member 40 positioned on the bottom surface 113 side and the longitudinal side surface 404 of the reflecting member 40 positioned on the top surface 114 side of the light emitting device 1000 from the back surface to the front surface direction (Z direction). It is preferable to incline inward. The inclination angle θ of the reflecting member 40 can be selected as appropriate, but from the viewpoint of ease of exhibiting such an effect and the strength of the reflecting member 40, it is preferably 0.3 ° or more and 3 ° or less, and 0.5 ° It is more preferably 2 ° or less and more preferably 0.7 ° or more and 1.5 ° or less. Moreover, it is preferable that the right side surface and the left side surface of the light emitting device 1000 have substantially the same shape. By doing so, the light emitting device 1000 can be reduced in size.

  As in the substrate 10 shown in FIG. 4, the first wiring 12 preferably includes a narrow portion having a short length in the Y direction and a wide portion having a long length in the Y direction in front view. The length D3 of the narrow portion in the Y direction is shorter than the length D4 of the wide portion in the Y direction. The narrow portion is separated from the center of the via 15 in the X direction when viewed from the front, and is located at a portion where the electrode of the light emitting element is located in the X direction. The wide portion is located at the center of the via 15 in a front view. Since the first wiring 12 includes the narrow portion, an area where the conductive adhesive member that electrically connects the electrode of the light emitting element and the first wiring spreads over the first wiring can be reduced. Thereby, it becomes easy to control the shape of the conductive adhesive member. The peripheral edge of the first wiring may have a rounded shape.

  As shown in FIG. 5A, the first wiring, the second wiring, and / or the third wiring may have a wiring main portion 12A and a plating 12B formed on the wiring main portion 12A. In this specification, the wiring refers to the first wiring, the second wiring, and / or the third wiring. As the wiring main portion 12A, a known material such as copper can be used. By having the plating 12B on the wiring main portion 12A, the reflectance on the surface of the wiring can be improved, or sulfidation can be suppressed. For example, the nickel plating 120A containing phosphorus may be located on the wiring main portion 12A. Since nickel improves the hardness by containing phosphorus, the hardness of the wiring is improved when the nickel plating 120A containing phosphorus is positioned on the wiring main portion 12A. Accordingly, it is possible to suppress the occurrence of burrs in the wiring when the wiring is cut due to the individualization of the light emitting device. The nickel plating containing phosphorus may be formed by an electrolytic plating method or may be formed by an electroless plating method.

  As shown in FIG. 5A, the gold plating 120B is preferably located on the outermost surface of the plating 12B. Since gold plating is located on the outermost surface of the plating, oxidation and corrosion on the surface of the first wiring 12, the second wiring 13, and / or the third wiring 14 are suppressed, and good solderability is obtained. It is possible to improve the reflectance and suppress sulfidation. The gold plating 120B located on the outermost surface of the plating 12B is preferably formed by an electrolytic plating method. The electrolytic plating method can contain a catalyst poison such as sulfur less than the electroless plating method. When an addition-reactive silicone resin using a platinum-based catalyst is cured at a position in contact with the gold plating, the gold plating formed by the electrolytic plating method has less sulfur content, so that the reaction between sulfur and platinum can be suppressed. . Thereby, it can suppress that the addition-reaction type silicone resin using a platinum-type catalyst raise | generates a curing defect. When forming the gold plating 120B in contact with the nickel plating 120A containing phosphorus, the nickel plating 120A and the gold plating 120B containing phosphorus are preferably formed by an electrolytic plating method. By forming the plating by the same method, the manufacturing cost of the light emitting device can be suppressed. Nickel plating may contain nickel, gold plating may contain gold, and other materials may contain it.

  The thickness of the nickel plating containing phosphorus is preferably larger than the thickness of the gold plating. When the thickness of the nickel plating containing phosphorus is larger than the thickness of the gold plating, the hardness of the first wiring 12, the second wiring 13, and / or the third wiring 14 can be easily improved. The thickness of the nickel plating containing phosphorus is preferably not less than 5 times and not more than 500 times the thickness of the gold plating, and more preferably not less than 10 times and not more than 100 times.

  As in the light emitting device 1000C shown in FIG. 5B, the wiring is formed by laminating a nickel plating 120C containing phosphorus, a palladium plating 120D, a first gold plating 120E, and a second gold plating 120F on the wiring main portion 12A. The plating 12B may be formed. When nickel plating 120C containing phosphorus, palladium plating 120D, first gold plating 120E, and second gold plating 120F are laminated, for example, when copper of wiring main part 12A is used, copper is contained in plating 12B. It can suppress spreading. Thereby, the fall of the adhesiveness of each layer of plating can be suppressed. The nickel plating 120C containing phosphorus, the palladium plating 120D, and the first gold plating 120E may be formed on the wiring main portion 12A by an electroless plating method, and the second gold plating 120F may be formed by an electrolytic plating method. Since the second gold plating 120F formed by the electrolytic plating method is located on the outermost surface, it is possible to suppress the curing failure of the addition reaction type silicone resin using the platinum-based catalyst.

  Hereinafter, each component in the light-emitting device which concerns on one Embodiment of this invention is demonstrated.

(Light emitting element 20)
The light emitting element 20 is a semiconductor element that emits light by applying a voltage, and a known semiconductor element composed of a nitride semiconductor or the like can be applied. Examples of the light emitting element 20 include an LED chip. The light emitting element 20 includes at least a semiconductor laminate 23, and in many cases further includes an element substrate 24. The top view shape of the light emitting element is preferably a rectangle, particularly a square shape or a rectangular shape that is long in one direction, but may be other shapes. For example, if it is a hexagonal shape, the light emission efficiency can be increased. The side surface of the light emitting element may be perpendicular to the upper surface, or may be inclined inward or outward. The light emitting element has positive and negative electrodes. The positive and negative electrodes can be composed of gold, silver, tin, platinum, rhodium, titanium, aluminum, tungsten, palladium, nickel, or an alloy thereof. The emission peak wavelength of the light-emitting element can be selected from the ultraviolet region to the infrared region depending on the semiconductor material and its mixed crystal ratio. As the semiconductor material, it is preferable to use a nitride semiconductor, which is a material capable of emitting light of a short wavelength that can efficiently excite the wavelength conversion particles. The nitride semiconductor is mainly represented by a general formula In _x Al _y Ga _1-xy N (0 ≦ x, 0 ≦ y, x + y ≦ 1). The light emission peak wavelength of the light emitting element is preferably 400 nm or more and 530 nm or less, more preferably 420 nm or more and 490 nm or less, and more preferably 450 nm or more and 475 nm or less from the viewpoints of light emission efficiency, excitation of wavelength conversion particles and color mixing relationship with the light emission, and the like. Even more preferable. In addition, an InAlGaAs-based semiconductor, an InAlGaP-based semiconductor, zinc sulfide, zinc selenide, silicon carbide, or the like can also be used. The element substrate of the light emitting element is a crystal growth substrate capable of mainly growing a semiconductor crystal constituting the semiconductor stacked body, but may be a bonding substrate bonded to a semiconductor element structure separated from the crystal growth substrate. . Since the element substrate has a light-transmitting property, it is easy to adopt flip chip mounting, and it is easy to increase the light extraction efficiency. Examples of the base material of the element substrate include sapphire, gallium nitride, aluminum nitride, silicon, silicon carbide, gallium arsenide, gallium phosphide, indium phosphide, zinc sulfide, zinc oxide, zinc selenide, diamond and the like. Of these, sapphire is preferable. The thickness of the element substrate can be appropriately selected, and is, for example, 0.02 mm or more and 1 mm or less. From the viewpoint of the strength of the element substrate and / or the thickness of the light emitting device, it is preferably 0.05 mm or more and 0.3 mm or less. .

(First wavelength conversion member 31)
The first wavelength conversion member is a member provided on the light emitting element. The first wavelength conversion member includes a first base material and first wavelength conversion particles.

(First wavelength conversion particle 311)
The first wavelength conversion particles absorb at least a part of the primary light emitted from the light emitting element and emit secondary light having a wavelength different from that of the primary light. The 1st wavelength conversion particle can be used individually by 1 type in the specific example shown below, or in combination of 2 or more types.

As the first wavelength conversion particles, known wavelength conversion particles such as wavelength conversion particles emitting green light, wavelength conversion particles emitting yellow light, and / or wavelength conversion particles emitting red light can be used. For example, as wavelength conversion particles emitting green light, yttrium / aluminum / garnet phosphors (for example, Y ₃ (Al, Ga) ₅ O ₁₂ : Ce), lutetium / aluminum / garnet phosphors (for example, Lu ₃ (Al, Ga) ₅ O ₁₂ : Ce), terbium / aluminum / garnet phosphor (for example, Tb ₃ (Al, Ga) ₅ O ₁₂ : Ce) phosphor, silicate phosphor (for example (Ba, Sr) ₂ SiO ₄ ) : Eu), chlorosilicate phosphor (for example, Ca ₈ Mg (SiO ₄ ) ₄ Cl ₂ : Eu), β sialon phosphor (for example, Si _6-z Al _z O _z N _8-z : Eu (0 <z <4.2)), SGS phosphor (e.g. SrGa ₂ S _4: Eu), and the like. As the wavelength conversion particles for yellow light emission, α sialon-based phosphors (for example, M _z (Si, Al) ₁₂ (O, N) ₁₆ (where 0 <z ≦ 2 and M is Li, Mg, Ca, Y) In addition, among the above-mentioned wavelength-converting particles that emit green light, there are also wavelength-converted particles that emit yellow light, such as yttrium, aluminum, and garnet phosphors. By substituting a part of Y with Gd, the emission peak wavelength can be shifted to the longer wavelength side, and yellow emission is possible, and among these, wavelength conversion particles capable of emitting orange are also included. Examples of wavelength converting particles that emit red light include nitrogen-containing calcium aluminosilicate (CASN or SCASN) -based phosphors (for example, (Sr, Ca) AlSiN ₃ : Eu). In addition, a manganese-activated fluoride-based phosphor (general formula (I) A ₂ [M _1-a Mn _a F ₆ ] is a phosphor represented by the formula (I) wherein A is K , Li, Na, Rb, Cs and NH ₄ , M is at least one element selected from the group consisting of Group 4 elements and Group 14 elements, and a As a typical example of this manganese-activated fluoride phosphor, there is a manganese-activated potassium fluorosilicate phosphor (for example, K ₂ SiF ₆ : Mn). .

(First base material 312)
The first base material 312 may be any material that has translucency with respect to light emitted from the light emitting element. The “translucency” means that the light transmittance at the emission peak wavelength of the light emitting element is preferably 60% or more, more preferably 70% or more, and still more preferably 80% or more. Say that. As the first base material, a silicone resin, an epoxy resin, a phenol resin, a polycarbonate resin, an acrylic resin, or a modified resin thereof can be used. Glass may be used. Of these, silicone resins and modified silicone resins are preferred because they are excellent in heat resistance and light resistance. Specific examples of the silicone resin include dimethyl silicone resin, phenyl-methyl silicone resin, and diphenyl silicone resin. The “modified resin” in this specification includes a hybrid resin.

  The first base material may contain various diffusing particles in the resin or glass. Examples of the diffusion particles include silicon oxide, aluminum oxide, zirconium oxide, and zinc oxide. As the diffusion particles, one of these can be used alone, or two or more of these can be used in combination. In particular, silicon oxide having a small thermal expansion coefficient is preferable. Further, by using nanoparticles as the diffusing particles, scattering of light emitted from the light emitting element can be increased, and the amount of wavelength conversion particles used can be reduced.

(Light guide member 50)
The light guide member is a member that bonds the light emitting element and the translucent member and guides light from the light emitting element to the translucent member. Examples of the base material of the light guide member include silicone resin, epoxy resin, phenol resin, polycarbonate resin, acrylic resin, and modified resins thereof. Of these, silicone resins and modified silicone resins are preferred because they are excellent in heat resistance and light resistance. Specific examples of the silicone resin include dimethyl silicone resin, phenyl-methyl silicone resin, and diphenyl silicone resin. Further, the base material of the light guide member may contain diffusing particles in the same manner as the first base material described above.

(Reflective member)
From the viewpoint of light extraction efficiency in the Z direction, the reflecting member preferably has a light reflectance at the emission peak wavelength of the light emitting element of 70% or more, more preferably 80% or more, and 90% or more. Even more preferably. Furthermore, the reflecting member is preferably white. Therefore, it is preferable that the reflecting member contains a white pigment in the base material. The reflective member goes through a liquid state before curing. The reflecting member can be formed by transfer molding, injection molding, compression molding, potting, or the like.

(Base material for reflective member)
As the base material of the reflecting member, a resin can be used, and examples thereof include silicone resin, epoxy resin, phenol resin, polycarbonate resin, acrylic resin, and modified resins thereof. Of these, silicone resins and modified silicone resins are preferred because they are excellent in heat resistance and light resistance. Specific examples of the silicone resin include dimethyl silicone resin, phenyl-methyl silicone resin, and diphenyl silicone resin.

(White pigment)
White pigments include titanium oxide, zinc oxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, calcium carbonate, calcium hydroxide, calcium silicate, magnesium silicate, barium titanate, barium sulfate, aluminum hydroxide, aluminum oxide, zirconium oxide, One of silicon oxides can be used alone, or two or more of these can be used in combination. The shape of the white pigment can be appropriately selected and may be indefinite or crushed, but is preferably spherical from the viewpoint of fluidity. Further, the particle diameter of the white pigment is, for example, about 0.1 μm or more and 0.5 μm or less. The content of the white pigment in the reflecting member can be appropriately selected. However, from the viewpoint of light reflectivity and viscosity in a liquid state, for example, it is preferably 10 wt% or more and 80 wt% or less, more preferably 20 wt% or more and 70 wt% or less, and 30 wt%. % To 60 wt% is even more preferable. Note that “wt%” is weight percent and represents the ratio of the weight of the material to the total weight of the reflecting member.

(Second wavelength conversion member 32)
The second wavelength conversion member can be made of the same material as the first wavelength conversion member.

(Coating member 33)
The second wavelength conversion member can use the same material as the first base material.

(Substrate 10)
The substrate 10 is a member on which the light emitting element is placed. The substrate 10 includes a base material 11, a first wiring 12, a second wiring 13, a third wiring 14, and a via 15.

(Substrate 11)
The base material 11 can be comprised using insulating members, such as resin or fiber reinforced resin, ceramics, and glass. Examples of the resin or fiber reinforced resin include epoxy, glass epoxy, bismaleimide triazine (BT), and polyimide. Examples of the ceramic include aluminum oxide, aluminum nitride, zirconium oxide, zirconium nitride, titanium oxide, titanium nitride, or a mixture thereof. Of these substrates, it is particularly preferable to use a substrate having physical properties close to the linear expansion coefficient of the light emitting element. The lower limit of the thickness of the substrate can be selected as appropriate, but is preferably 0.05 mm or more and more preferably 0.2 mm or more from the viewpoint of the strength of the substrate. The upper limit value of the thickness of the base material is preferably 0.5 mm or less, and more preferably 0.4 mm or less, from the viewpoint of the thickness (depth) of the light emitting device.

(First wiring 12, second wiring 13, third wiring 14)
The first wiring is disposed on the front surface of the substrate and is electrically connected to the light emitting element. The second wiring is disposed on the back surface of the substrate and is electrically connected to the first wiring through the via. The third wiring covers the inner wall of the recess and is electrically connected to the second wiring. The first wiring, the second wiring, and the third wiring can be formed of copper, iron, nickel, tungsten, chromium, aluminum, silver, gold, titanium, palladium, rhodium, or an alloy thereof. A single layer or a multilayer of these metals or alloys may be used. In particular, copper or a copper alloy is preferable from the viewpoint of heat dissipation. Further, the surface layer of the first wiring and / or the second wiring is a layer of silver, platinum, aluminum, rhodium, gold, or an alloy thereof from the viewpoint of wettability and / or light reflectivity of the conductive adhesive member. May be provided.

(Via 15)
The via 15 is a member that is provided in a hole penetrating the front surface and the back surface of the substrate 11 and electrically connects the first wiring and the second wiring. The via 15 may be configured by a fourth wiring 151 that covers the surface of the through hole of the base material, and a filling member 152 that fills the fourth wiring 151. For the fourth wiring 151, a conductive member similar to the first wiring, the second wiring, and the third wiring can be used. As the filling member 152, a conductive member or an insulating member may be used.

(Insulating film 18)
The insulating film 18 is a member that ensures insulation on the back surface and prevents a short circuit. The insulating film may be formed of any of those used in the field. For example, a thermosetting resin or a thermoplastic resin can be used.

(Conductive adhesive member 60)
The conductive adhesive member is a member that electrically connects the electrode of the light emitting element and the first wiring. Examples of conductive adhesive members include gold, silver, copper and other bumps, silver, gold, copper, platinum, aluminum, metal paste including resin binder, tin-bismuth, tin-copper, tin -Any one of solders such as silver-based, gold-tin-based solders, and low melting point metals can be used.

  A light emitting device according to an embodiment of the present invention includes a backlight device for a liquid crystal display, various lighting fixtures, a large display, various display devices such as advertisements and destination guides, a projector device, a digital video camera, a facsimile machine, and a copier. It can be used for an image reading device in a scanner or the like.

1000, 1000A, 1000B, 1000C Light emitting device 10 Substrate 11 Base 12 First wiring 13 Second wiring 14 Third wiring 15 Via
151 4th wiring
152 Filling member 16 Depression 18 Insulating film 20 Light emitting element 31 First wavelength conversion member 32 Second wavelength conversion member 33 Cover member 34 Coating 40 Reflective member 50 Light guide member 60 Conductive adhesive member

Claims (8)

A light emitting device having a first surface and a second surface located on the opposite side of the first surface;
A light guide member covering a side surface of the light emitting element;
A first wavelength conversion member covering the first surface and having a first base material and first wavelength conversion particles;
A side surface of the light emitting element, a side surface of the light guide member and a side surface of the first wavelength conversion member, and a reflective member in contact with the light emitting element,
The thickness of the first wavelength conversion member is 60 μm or more and 120 μm or less,
The average particle diameter of the first wavelength conversion particles is 4 μm or more and 12 μm or less,
The center particle diameter of the first wavelength conversion particles is 4 μm or more and 12 μm or less,
The light-emitting device whose said 1st wavelength conversion particle | grain is 60 to 75 weight% with respect to the total weight of a said 1st wavelength conversion member.   The light emitting device according to claim 1, wherein the first wavelength conversion particle is a manganese-activated fluoride phosphor.   The light emitting device according to claim 1, further comprising a second wavelength conversion member that is located between the light emitting element and the first wavelength conversion member and includes a second base material and second wavelength conversion particles.   The light emitting device according to claim 3, wherein an average particle diameter of the first wavelength conversion particles is smaller than an average particle diameter of the second wavelength conversion particles.   The light emitting device according to claim 3 or 4, wherein the second wavelength conversion particles are β sialon phosphors.   The thickness of the said 2nd wavelength conversion member is 20 micrometers or more and 60 micrometers or less, The light-emitting device of any one of Claim 3 to 5.   The light emitting device according to claim 1, further comprising a covering member that covers the first wavelength conversion member.   8. The light emitting device according to claim 1, wherein a standard deviation of a particle size distribution based on a volume of the first wavelength conversion member is 0.3 μm or less.

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