JP7144693B2 - light emitting device - Google Patents

Description

The present invention relates to light emitting devices.

A light-emitting element, an optical layer disposed on the light-emitting element that transmits at least part of the light emitted by the light-emitting element, and a plate-shaped material that is mounted on the optical layer and transmits at least part of the light emitted by 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, there is a demand for a light-emitting device capable of obtaining light of uniform chromaticity regardless of location. Accordingly, an object of the embodiments of the present invention is to provide a light-emitting device capable of suppressing unevenness in light distribution chromaticity.

A light-emitting device according to an aspect of the present invention includes a light-emitting element having a first surface and a second surface opposite to the first surface; a light guide member covering a side surface of the light-emitting element; a first wavelength conversion member that covers the first surface and has a first base material and first wavelength conversion particles; and 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 reflecting member in contact with the light emitting element, wherein the thickness of the first wavelength conversion member is 60 μm or more and 120 μm or less, the average particle size of the first wavelength conversion particles is 4 μm or more and 12 μm or less, and The median particle size of the first wavelength conversion particles is 4 μm or more and 12 μm or less, and the first wavelength conversion particles are 60% by weight or more and 75% by weight or less with respect to the total weight of the first wavelength conversion member.

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

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. FIG. 2A is a schematic cross-sectional view along line 2A-2A of FIG. 1C. FIG. 2B is a schematic cross-sectional view along line 2B-2B of FIG. 1C. 2C is a schematic cross-sectional view of a modification 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 Embodiment 1. FIG. 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. 4 is a schematic side view of a substrate according to Embodiment 1. FIG. 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 the dotted line portion. 5B is a schematic cross-sectional view of a modification of the light-emitting device according to Embodiment 1, and an enlarged view showing the inside of the dotted line portion.

Hereinafter, embodiments of the invention will be described 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 unless there is a specific description, the present invention is not limited to the following. Also, the content described in one embodiment can also be applied to the modification. Furthermore, the sizes and positional relationships of members shown 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 a light-emitting element 20 , a light guide member 50 , a first wavelength conversion member 31 and a reflection member 40 . The light emitting element 20 has a first surface 201 and a second surface 203 opposite the first surface 201 . The light guide member 50 covers the side surface 202 of the light emitting element. first
The wavelength conversion member 31 covers the first surface 201 of the light emitting element. Moreover, the first wavelength conversion member 31
has a first matrix 312 and first wavelength-converting particles 311 . The thickness of the first wavelength conversion member 31 is 60 μm or more and 120 μm or less. The average particle size of the first wavelength conversion particles 311 is 4 μm.
It is more than 12 micrometers or less. The central 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% by weight or more and 75% by weight or less with respect to the total weight of the first wavelength conversion member 31 . The reflective 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. Also, the reflecting member 40 is in contact with the light emitting element. A 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 contained in the first wavelength conversion member 31 is 4 μm or more.
2 μm or less. Since the average particle diameter of the first wavelength conversion particles 311 is 12 μm or less, when the concentration of the first wavelength conversion particles 311 contained in the first wavelength conversion member 31 is the same, the first base material 312 and the first wavelength The interface with conversion particles 311 can be increased. By increasing the interface between the first base material and the first wavelength-converting particles, the light from the light-emitting element is more likely to be diffused by the interface between the first base material and the first wavelength-converting particles. As a result, the light from the light emitting element is diffused within the first wavelength conversion member, so that unevenness in light distribution chromaticity of the light emitting device can be suppressed. When the average particle size of the first wavelength conversion particles is 4 μm or more, it becomes easier to extract light from the light emitting element, and thus the light extraction efficiency of the light emitting device is improved.

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

The central particle diameter of the first wavelength conversion particles 311 contained in the first wavelength conversion member 31 is 4 μm or more.
2 μm or less. When the concentration of the first wavelength-converting particles 311 contained in the first wavelength-converting member 31 is the same, the first
The interface between the base material and the first wavelength-converting particles increases. By increasing the interface between the first base material and the first wavelength-converting particles, the light from the light-emitting element is more likely to be diffused by the interface between the first base material and the first wavelength-converting particles. As a result, the light from the light emitting element is diffused within the first wavelength conversion member, so that unevenness in light distribution chromaticity of the light emitting device can be suppressed. The central particle size of the first wavelength conversion particles is
When the thickness is 4 μm or more, it becomes easy to extract light from the light-emitting element, so that the light-extraction efficiency of the light-emitting device is improved.

In this specification, the central particle diameter of the first wavelength conversion particles 311 is the volume average particle diameter (median diameter), and the particle diameter at which the volume cumulative frequency from the small diameter side reaches 50% (D50: median diameter) It's about. Laser diffraction particle size distribution analyzer (MASTER manufactured by MALVERN
SIZER 2000) can measure the median particle size.

The particle diameter (D10) at which the volume cumulative frequency from the small diameter side of the first wavelength conversion particles reaches 10% is 6
It is preferable that the thickness is 10 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 volume-based particle size distribution of the first wavelength-converting particles is preferably 0.3 μm or less. Since there is little variation in the first wavelength conversion particles, it becomes easy to form the wavelength conversion member 31 with a uniform thickness.

Examples of the first wavelength-converting particles include manganese-activated fluoride-based phosphors. A manganese-activated fluoride-based phosphor is a preferable member from the viewpoint of color reproducibility because it 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. Since the thickness of the first wavelength conversion member 31 is 120 μm or less, the thickness of the light emitting device can be reduced. The thickness of the first wavelength conversion member is the thickness of the first wavelength conversion member in the Z direction.

60% by weight or more of the first wavelength conversion particles 311 with respect to the total weight of the first wavelength conversion member 31
5% by weight or less. Since the content of the first wavelength conversion particles increases when the first wavelength conversion particles are 60% by weight or more with respect to the total weight of the first wavelength conversion member, the first base material and the first wavelength conversion particles interface with increases. By increasing the interface between the first base material and the first wavelength-converting particles, the light from the light-emitting element is more likely to be diffused by the interface between the first base material and the first wavelength-converting particles. As a result, the light from the light emitting element is diffused within the first wavelength conversion member, so that unevenness in light distribution chromaticity of the light emitting device can be suppressed. Since the ratio of the first base material in the first wavelength conversion member increases when the first wavelength conversion particles are 75% by weight or less with respect to the total weight of the first wavelength conversion member, the first wavelength conversion member Breakage can be suppressed. In addition, the first wavelength conversion member may have only the first wavelength conversion particles as the wavelength conversion particles, or may have wavelength conversion particles of a different material from the first wavelength conversion particles.

The light emitting device may include a second wavelength converting member 32 positioned between the light emitting element 20 and the first wavelength converting member 31 like the light emitting device 1000 shown in FIG. 2A, or the light emitting device 1000A shown in FIG. 2C. It is not necessary to provide the second wavelength conversion member located between the light emitting element 20 and the first wavelength conversion member 31 as in . The second wavelength conversion member 32 includes a second base material 322 and second wavelength conversion particles 321 . The average particle size of the first wavelength conversion particles 311 is preferably smaller than the average particle size of the second wavelength conversion particles 321 . Since the average particle size of the second wavelength conversion particles is larger than the average particle size of the first wavelength conversion particles, the light from the light emitting element can be easily guided to the second wavelength conversion member 32, so the light extraction efficiency of the light emitting device improves. In addition, since the average particle size of the first wavelength conversion particles 311 is smaller than the average particle size of the second wavelength conversion particles 321, the light from the light emitting element is easily diffused within the first wavelength conversion member 31, and the light emitting device light distribution chromaticity unevenness can be suppressed. The material of the first wavelength-converting particles and the material of the second wavelength-converting particles may be the same or different. Also, 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 twenty-second wavelength conversion member 32 is improved. first
Since the material of the base material 312 and the material of the second base material 322 are different, a refractive index difference occurs between the first base material 312 and the second base material 322 . This makes it easier for the light from the light emitting element to diffuse at the interface between the first base material 312 and the second base material 322, so that unevenness in light distribution chromaticity of the light emitting device can be suppressed. The refractive index of the first base material 312 is preferably higher than that of the second base material 322 . By doing so, it is possible to suppress total reflection of the light from the light emitting element at the interface between the first base material 312 and the second base material 322 . This improves the light extraction efficiency of the light emitting device.

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 thickness of the light emitting device can be reduced. 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 of the thickness of the first wavelength conversion member 31 . By doing so, the first wavelength conversion member 31 is more likely to be irradiated with the light from the light emitting element than when the second wavelength conversion member 32 is thick. For example, the number of first wavelength conversion members 31 is 8
In the case of 0±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 covering the first wavelength conversion member 31 to be described later may be equal to the thickness of the first wavelength conversion member 31 . For example, if the thickness of the first wavelength conversion member 31 is 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 this specification, equivalent thickness means that a variation of about 5 μm is allowed.

The peak wavelength of the light from the second wavelength conversion particles 321 excited by the light emitting element is preferably shorter than the peak wavelength of the light from the first wavelength converting particles 311 excited by the light emitting element. Since the peak wavelength of the light from the second wavelength conversion particles 321 excited by the light emitting element is shorter than the peak wavelength of the light from the first wavelength conversion particles 311 excited by the light emitting element, the light is excited by the light emitting element. The first wavelength converting particles can be excited by light from the second wavelength converting particles.
This can increase the light from the excited first wavelength-converting particles. Since the first wavelength conversion member 31 is arranged on the second wavelength conversion member 32, 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 the light from the first wavelength conversion particles 311 excited by the light emitting element is 610 nm or more and 750 nm or less, and the peak wavelength of the light from the second wavelength conversion particles 321 excited by the light emitting element is 500 nm or more and 570 nm or less. Preferably. By doing so, a light-emitting device with high color rendering properties can be obtained. A light-emitting element (blue light-emitting element) having an emission peak wavelength in the range of 430 nm or more and 475 nm or less, a first wavelength conversion particle having a peak wavelength of light from being excited by the light-emitting element of 610 nm or more and 750 nm or less, and excited by the light-emitting element. A light-emitting device that emits white light can be obtained by combining with the second wavelength-converting particles whose light has a peak wavelength of 500 nm or more and 570 nm or less. For example, the first wavelength-converting particles may be a manganese-activated potassium fluorosilicate phosphor, and the second wavelength-converting particles may be a β-sialon-based phosphor. When manganese-activated potassium fluorosilicate phosphor is used as the first wavelength-converting particles, it is particularly preferable to provide the second wavelength-converting member 32 positioned between the light-emitting element 20 and the first wavelength-converting member 31. . The first manganese-activated fluoride phosphor
The wavelength conversion particles tend to cause luminance saturation, but since the second wavelength conversion member 32 is positioned between the first wavelength conversion member 31 and the light emitting element 20, the light from the light emitting element is excessively absorbed by the first wavelength conversion particles. Irradiation can be suppressed. This makes it possible to suppress deterioration of the first wavelength-converting particles, which are manganese-activated fluoride phosphors.

As shown in FIG. 2A, the light emitting element 20 has a first surface 201 and a second surface 203 opposite 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. As shown in FIG. The positive and negative electrodes 21 and 22 are 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 wires for supplying electricity to the positive and negative electrodes of the light-emitting element, so that the size of the light-emitting device can be reduced. When the light emitting element is flip-chip mounted, the positive and negative electrodes 21 and 22 of the light emitting element are located on the second surface 203 . Although the light emitting device 20 has the device substrate 24 in this embodiment, the device 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 higher transmittance of light from the light emitting element 20 than the reflecting member 40 . Therefore, the light guide member 50 is located on the side surface 2 of the light emitting element.
By covering up to 02, 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, so that the light extraction efficiency can be improved. Further, the light guide member 50 may be positioned between the first surface 201 of the light emitting element and the translucent member 30, or may be positioned between the first surface 201 of the light emitting element and the translucent member 30. It doesn't 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 attached to the first surface 20 of the light emitting element.
1 and the translucent member 30, the bonding strength between the light emitting element and the translucent member is improved.

The reflective 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. By doing so, it is possible to obtain a light-emitting device having a high contrast between the light-emitting region and the non-light-emitting region, and having good "parting property". At least a part of the reflecting member 40 is in contact with the light emitting element. At least a part of the reflecting member 40 is in contact with the light emitting element, so that the size of the light emitting device can be reduced. The reflecting member 40 is preferably in contact with the second surface 203 of the light emitting element. By doing so, it is possible to prevent the light from the light emitting element from being absorbed by the substrate on which the light emitting element is mounted.

Like the light emitting device 1000 shown in FIG. 2A, the covering member 3 covering the first wavelength conversion member 31
3 may be provided. The covering member 33 does not substantially contain wavelength converting particles. first
By providing the covering member 33 that covers the wavelength converting member 31, even if the first wavelength converting particles that are vulnerable to moisture are used, the covering member 33 also functions as a protective layer, so deterioration of the first wavelength converting particles can be suppressed. . Wavelength conversion particles that are susceptible to moisture include, for example, manganese-activated fluoride phosphors. A manganese-activated fluoride-based phosphor is a preferable member from the viewpoint of color reproducibility because it can emit light with a relatively narrow spectral line width. "Containing substantially no wavelength converting particles" means not excluding the wavelength converting particles that are inevitably mixed, and the content of the wavelength converting particles is preferably 0.05% by weight or less. In this 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 the translucent member 30 .

A film 34 covering the upper surface of the translucent member 30, as in the light emitting device 1000C shown in FIG. 2D
may be provided. The coating 34 is an aggregate of coating particles that are nanoparticles. In addition, the coating may be only coating particles, or may include coating particles and a resin material. By making the refractive index of the film different from the refractive index of the base material of the translucent member located on the outermost surface, it is possible to correct the emission chromaticity of the light emitting device. The base material of the light-transmitting member positioned on the outermost surface means the base material of the layer forming the surface of the light-transmitting member opposite to the light extraction surface side of the light emitting element. For example, coating 3
When the refractive index of 4 is greater than the refractive index of the base material of the light-transmitting member positioned on the outermost surface, the reflected light component at the interface between the film and the air is the base material of the light-transmitting member positioned on the outermost surface. It increases more than the reflected light component at the air interface. Therefore, the reflected light component returning to the translucent member can be increased, and the wavelength conversion particles can be easily excited. Thereby, the emission chromaticity of the light emitting device can be corrected to the longer wavelength side. Further, 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. is less than the reflected light component at . As a result, the reflected light component returning to the translucent member can be reduced, making it difficult to excite the wavelength conversion particles. Thereby, the emission chromaticity of the light emitting device can be corrected to the short wavelength side. For example, when a phenyl-based silicone resin is used as the base material of the light-transmitting member positioned on the outermost surface, titanium oxide, titanium oxide, aluminum oxide, etc. are used as coating particles for correcting the emission chromaticity of the light-emitting device toward the longer wavelength side. is mentioned. When the base material of the translucent member located on the outermost surface is a phenyl-based silicone resin, silicon oxide or the like can be used as coating particles for correcting the emission chromaticity of the light emitting device toward the short wavelength side. When 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 or not to form a film covering the upper surface of the translucent member can be appropriately selected in accordance with the correction of the emission chromaticity of the light emitting device.
When the light-emitting device includes a plurality of light-transmitting members, the upper surface of one of the light-transmitting members is coated with a film having a higher refractive index than the base material of the light-transmitting member positioned on the outermost surface. Alternatively, the upper surface of the other light-transmitting member may be coated with a film having a lower refractive index than the base material of the light-transmitting member located on the outermost surface. The material of the film covering the translucent member can be appropriately selected in accordance with the correction of the emission chromaticity of the light emitting device. The coating can be formed by a known method such as potting with a dispenser, ink jetting or spraying.

The light-emitting device may include a substrate 10 on which light-emitting elements are mounted. For example, the substrate 10 includes a substrate 11 , first wiring 12 , second wiring 13 , third wiring 14 and vias 15 .
The base material 11 has a front surface 111 extending in a first longitudinal direction and a second transverse direction, a rear surface 112 located on the opposite side of the front surface, and a bottom surface adjacent to the front surface 111 and orthogonal to the front surface 111. 113 and a top surface 114 located opposite the bottom surface 113 . Substrate 11 also has at least one depression 16 . The first wiring 12 is arranged on the front surface 111 of the base material 11 . The second wiring 13 is arranged on the back surface 112 of the base material 11 . The light emitting element 20 is connected to the first wiring 12
and is placed on the first wiring 12 . The reflective member 40 covers the side surface 202 of the light emitting element 20 and the front surface 111 of the substrate. At least one indentation opens to the rear surface 112 and the bottom surface 113 . A 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 . Also, the vias 15 extend from the front surface 111 to the back surface 11 of the substrate 11 .
passes through 2. In this specification, the term "perpendicular" means that an inclination of about ±3° from 90° is allowed.

The via 15 may be in contact with the third wiring, or 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 is transferred from the first wiring 12 to the via 1.
5 to the second wiring 13 and/or the third wiring 14, the light emitting device 1
000 heat dissipation can be improved. When the via 15 is spaced apart from the third wiring, the via and the recess do not overlap when viewed from the rear, thereby improving the strength of the substrate. 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 via 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 has a convex portion 121 . By positioning the positive and negative electrodes 21 and 22 of the light emitting element 20 on the convex portion 121 of the first wiring 12 , the first wiring 12 and the positive and negative electrodes 21 and 2 of the light emitting element are bonded to each other via the conductive adhesive member 60 .
2, the alignment of the light emitting element and the substrate can be easily performed due to the self-alignment effect.

The via 15 preferably has a circular shape when viewed from the rear. By doing so, it can be easily formed by a drill or the like. In this specification, the circular shape includes not only a perfect circle but also a shape close thereto (for example, an elliptical shape or a shape in which the four corners of a square are chamfered into large arcs).

The via 15 may be configured by filling a conductive material into a through-hole of the base material.
As shown in A, a fourth wiring 151 covering the surface of the through-hole of the base material and a filling member 152 filling a region surrounded by the fourth wiring 151 may be provided. Fill member 152 may be conductive or insulating. A resin material is preferably used for the filling member 152 .
In general, the resin material before hardening has higher fluidity than the metal material before hardening.
Easy to fill inside. Therefore, using a resin material for the filling member facilitates manufacturing of the substrate. As a resin material that can be easily filled, for example, an epoxy resin can be used. When a resin material is used as the filling member, it is preferable to contain an additive member in order to lower the coefficient of linear expansion. By doing so, the difference in linear expansion coefficient from that of the fourth wiring becomes smaller, so it is possible to suppress formation of a gap between the fourth wiring and the filling member due to heat from the light emitting element. Examples of the added member include silicon oxide. Moreover, when a metal material is used for the filling member 152, heat dissipation can be improved. When the vias 15 are formed by filling the through holes of the base material with a conductive material, it is preferable to use a metal material such as Ag or Cu, which has high thermal conductivity.

The light emitting device 1000 can be fixed to the mounting substrate by a bonding member such as solder formed in the recess 16 . The substrate may have one or more recesses. By having a plurality of depressions, it is possible to improve the bonding strength between the light emitting device 1000 and the mounting substrate. The depth of the recess may be the same on the top surface side and the bottom surface side, or may be deeper on the bottom surface side than on the top surface side. As shown in FIG. 2B, the depth of the depression 16 in the Z direction is deeper on the bottom side than on the top side,
In the Z direction, the thickness W1 of the substrate located on the top surface side of the recess can be made thicker than the thickness W2 of the substrate located on the bottom surface side of the recess. Thereby, the strength reduction of the base material can be suppressed. In addition, since the depth W3 of the recess on the bottom surface side is deeper than the depth W4 of the recess on the top surface side, the volume of the bonding member formed in the recess increases. 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 board are mounted facing each other, the bottom surface 1 of the base material 11
Even in the case of the side-light emitting type (side-view type) in which 13 and the mounting board are mounted facing each other, the bonding strength with the mounting board 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 emission type. Since the depth of the depression in the Z direction is deeper on the bottom side than on the top side, the area of the opening of the depression on the bottom can be increased. By increasing the area of the opening of the recess on the bottom surface facing the mounting substrate, the area of the bonding member located on the bottom surface can also be increased. As a result, the area of the bonding member located on the surface facing the mounting substrate can be increased, so that the bonding strength between the light emitting device 1000 and the mounting substrate can be improved.

The maximum depth of the depression in the Z direction is 0.4 to 0.9 times the thickness of the substrate in the Z direction.
Double is preferred. When the depth of the recess is more than 0.4 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. When the depth of the recess is shallower than 0.9 times the thickness of the base material, it is possible to suppress a decrease in the strength of the base material.

As shown in FIG. 2B, the recess 16 preferably has a parallel portion 161 extending from the rear surface 112 in a direction parallel to the bottom surface 113 (the Z direction). By providing the parallel portion 161, the volume of the recess can be increased even if the area of the opening of the recess on the back surface is the same. By increasing the volume of the recess, the amount of bonding material 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 this specification, parallel means allowing an inclination of about ±3°. Further, in a cross-sectional view, the depression 16 includes an inclined portion 162 inclined from the bottom surface 113 in a direction in which the thickness of the base material 11 increases. The inclined portion 162 may be straight or curved.

The maximum height of the depressions in the Y direction is 0.3 to 0.7 times the thickness of the substrate in the Y direction.
Five times is preferred. When 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. can. When the length of the depression in the Y direction is shallower than 0.75 times the thickness of the base material, it is possible to suppress a decrease in the strength of the base material.

As shown in FIG. 3A, when there are a plurality of depressions 16 on the back surface, they are preferably positioned symmetrically with respect to the center line 3C of the substrate parallel to the Y direction. By doing so, self-alignment works effectively when the light-emitting device is mounted on the mounting substrate via the bonding member.
The light emitting device can be accurately mounted within the mounting range.

The light emitting device may include an insulating film 18 that partially covers the second wiring 13 . By providing the insulating film 18, it is possible to ensure insulation and prevent short circuits on the back surface. Moreover, it is possible to prevent the second wiring from being peeled off from the base material.

In the bottom surface, the depth of the depression in the Z direction may be substantially constant, or the depth of the depression may be different between the center and the end. As shown in FIG. 3B, on the bottom surface, the depth D1 at the center of the depression 16
is the maximum depth of the recess in the Z direction. By doing so, it is possible to increase the thickness D2 of the substrate in the Z direction at the end of the depression in the X direction on the bottom surface, so that the strength of the substrate can be improved. In this specification, the term "center" means that a variation of about 5 μm is allowed. The depression 16 can be formed by a known method such as drilling or laser.

As shown in FIG. 3C, the longitudinal side surface 403 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. By doing so, when the light emitting device 1000 is mounted on the mounting substrate, contact between the side surface 403 of the reflecting member 40 and the mounting substrate is suppressed, and the mounting attitude of the light emitting device 1000 tends to be stable. A longitudinal side surface 404 of the reflecting member 40 located on the upper surface 114 side is preferably inclined toward the inside of the light emitting device 1000 in the Z direction. By doing so, contact between the side surface of the reflecting member 40 and the suction nozzle (collet) is suppressed, and damage to the reflecting member 40 during suction of the light emitting device 1000 can be suppressed. In this way, the longitudinal side surface 403 of the reflecting member 40 located on the bottom surface 113 side and the longitudinal side surface 404 of the reflecting member 40 located on the top surface 114 side are the same as those of the light emitting device 1000 in the front direction (Z direction) from the back surface. It is preferably slanted inwards. Although the inclination angle θ of the reflecting member 40 can be selected as appropriate, it is preferably 0.3° or more and 3° or less, and 0.5° from the viewpoint of the ease of achieving such effects and the strength of the reflecting member 40 .
It is more preferably 0.7° or more and 1.5° or less, more preferably 0.7° or more and 1.5° or less. Moreover, it is preferable that the right side and the left side of the light emitting device 1000 have substantially the same shape. By doing so, the light emitting device 1000 can be miniaturized.

Like the substrate 10 shown in FIG. 4, the first wiring 12 preferably has a narrow portion with a short length in the Y direction and a wide portion with a long length in the Y direction when viewed from the front. 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 located in the X direction away from the center of the via 15 when viewed from the front and in the portion where the electrode of the light emitting element is located in the X direction. The wide portion is positioned at the center of the via 15 when viewed from the front. Since the first wiring 12 has the narrow portion, it is possible to reduce the area over which the conductive adhesive member that electrically connects the electrode of the light emitting element and the first wiring wets and spreads over the first wiring. This makes it easier to control the shape of the conductive adhesive member. Note that the peripheral portion of the first wiring may have a rounded shape.

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

As shown in FIG. 5A, gold plating 120B is preferably located on the outermost surface of plating 12B. Since the gold plating is positioned on the outermost surface of the plating, the first wiring 12 and the second wiring 1
3 and/or the surface of the third wiring 14 is suppressed from oxidizing and corroding, and good solderability is obtained. Reflectance can be improved and sulfuration can be suppressed. The gold plating 120B located on the outermost surface of the plating 12B is preferably formed by electroplating. The electroplating method can reduce the content of catalyst poisons such as sulfur as compared with the electroless plating method. When curing an addition reaction type silicone resin using a platinum-based catalyst at a position in contact with gold plating,
Since the gold plating formed by the electroplating method contains little sulfur, it is possible to suppress the reaction between sulfur and platinum. As a result, it is possible to prevent the addition reaction type silicone resin using a platinum-based catalyst from causing poor curing. When forming the gold plating 120B in contact with the nickel plating 120A containing phosphorus, the nickel plating 120A containing phosphorus and the gold plating 120
B is preferably formed by electroplating. By forming the plating in the same way,
The manufacturing cost of the light emitting device can be suppressed. Nickel plating may contain nickel, gold plating may contain gold, and may contain other materials.

The nickel plating containing phosphorus is preferably thicker than the gold plating. Since the thickness of the nickel plating containing phosphorus is thicker than the thickness of the gold plating, the first wiring 12 and the second wiring 1
3 and/or the hardness of the third wiring 14 can be easily improved. The thickness of the nickel plating containing phosphorus is preferably 5 to 500 times, more preferably 10 to 100 times, the thickness of the gold plating.

As in the light-emitting device 1000C shown in FIG. 5B, the wiring consists of nickel plating 120C containing phosphorus on the main wiring portion 12A, palladium plating 120D, first gold plating 120E, and second gold plating 120E.
The gold plating 120F and the plating 12B may be laminated. By stacking the phosphorous-containing nickel plating 120C, the palladium plating 120D, the first gold plating 120E, and the second gold plating 120F, for example, when copper is used for the wiring main portion 12A, the plating 12B
It is possible to suppress the diffusion of copper inside. As a result, it is possible to suppress deterioration in the adhesion of each layer of plating. A nickel plating 120C containing phosphorus, a palladium plating 120D, and a first gold plating 120E are formed on the wiring main portion 12A by electroless plating.
0F may be formed by electroplating. Second gold plating 1 formed by electrolytic plating
By positioning 20F on the outermost surface, it is possible to suppress poor curing of the addition reaction type silicone resin using a platinum-based catalyst.

Each component in the light-emitting device according to one embodiment of the present invention will be described below.

(Light emitting element 20)
The light emitting element 20 is a semiconductor element that emits light by itself when a voltage is applied, and a known semiconductor element made of a nitride semiconductor or the like can be applied. As the light emitting element 20, for example, an LED
Chips are included. The light emitting device 20 comprises at least a semiconductor stack 23 and often further comprises a device substrate 24 . The top view shape of the light emitting element is preferably a rectangle, particularly a square shape or a rectangular shape elongated in one direction, but may be another shape, such as a hexagonal shape, which can increase the luminous efficiency. The side surface of the light emitting element may be perpendicular to the top surface, or may be inclined inward or outward. In addition, the light emitting element has positive and negative electrodes. The positive and negative electrodes are gold, silver, tin, platinum, rhodium, titanium, aluminum, tungsten,
It can be composed of palladium, nickel or alloys 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 short-wavelength light that can efficiently excite the wavelength conversion particles. Nitride semiconductors mainly have the general formula In _x
Al _y Ga _1-xy N (0≦x, 0≦y, x+y≦1). The 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 viewpoint of luminous efficiency, excitation of the wavelength conversion particles, and color mixing relationship with light emission. more preferred. In addition, InAlG
AAs-based semiconductors, InAlGaP-based semiconductors, zinc sulfide, zinc selenide, silicon carbide, and the like can also be used. The element substrate of the light emitting element is mainly a crystal growth substrate on which semiconductor crystals constituting the semiconductor laminate can be grown, but it may be a bonding substrate that is separated from the crystal growth substrate and bonded to the semiconductor element structure. . Since the element substrate has translucency, it is easy to employ flip-chip mounting, and it is easy to increase the light extraction efficiency. As the base material of the element substrate,
Sapphire, gallium nitride, aluminum nitride, silicon, silicon carbide, gallium arsenide, gallium phosphide, indium phosphide, zinc sulfide, zinc oxide, zinc selenide, diamond and the like. Among them, sapphire is preferred. The thickness of the element substrate can be selected as appropriate.
. The thickness is 02 mm or more and 1 mm or less, and from the viewpoint of the strength of the element substrate and/or the thickness of the light emitting device, the thickness is preferably 0.05 mm or more and 0.3 mm or less.

(First wavelength conversion member 31)
A 1st wavelength conversion member is a member provided on a 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-converting particles absorb at least part of the primary light emitted by the light-emitting element and emit secondary light with a wavelength different from that of the primary light. As the first wavelength-converting particles, one of the specific examples shown below can be used alone, or two or more of them can be used in combination.

As the first wavelength conversion particles, known wavelength conversion particles such as green light emission wavelength conversion particles, yellow light emission wavelength conversion particles, and red light emission wavelength conversion particles can be used. For example, wavelength conversion particles that emit green light include yttrium _- aluminum-garnet-based phosphors (e.g., Y3(Al, Ga) _5O12 :Ce), lutetium-aluminum-garnet-based phosphors (e.g., _{Lu3 (} Al, Ga) ₅ O ₁₂ :Ce), terbium-aluminum-garnet-based phosphors (for example, Tb ₃ (Al, Ga) ₅ O ₁₂ :Ce)-based phosphors, silicate-based phosphors (for example, (Ba, Sr) ₂ SiO ₄ : Eu), chlorosilicate phosphors (
For example, Ca ₈ Mg(SiO ₄ ) ₄ Cl ₂ :Eu), β-sialon-based phosphor (eg, Si _{6
-zAlzOzN8 -z :} Eu (0< _z <4.2)), SGS-based phosphors (for example, SrGa
₂ S ₄ :Eu) and the like. As 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 L
i, Mg, Ca, Y, and lanthanide elements excluding La and Ce). In addition, among the wavelength conversion particles that emit green light, there are wavelength conversion particles that emit yellow light. Further, for example, yttrium-aluminum-garnet-based phosphors can emit yellow light by substituting part of Y with Gd to shift the emission peak wavelength to the longer wavelength side. again,
Among these are also wavelength-converting particles capable of orange emission. Examples of wavelength conversion particles that emit red light include nitrogen-containing calcium aluminosilicate (CASN or SCASN) phosphors (for example, (
Sr, Ca) AlSiN ₃ :Eu) and the like. In addition, a manganese-activated fluoride-based phosphor (a phosphor represented by the general formula (I) A ₂ [M _{1-a Mna} F ₆ ]) (wherein in the general formula (I), A is is at least one selected from the group consisting of K, Li, Na, Rb, Cs and NH4, M is at least one element selected from the group consisting of Group ₄ elements and Group 14 elements, a satisfies 0<a<0.2)). Representative examples of manganese-activated fluoride-based phosphors include manganese-activated potassium fluorosilicate phosphors (
For example, K ₂ SiF ₆ :Mn).

(First base material 312)
The first base material 312 may be any material as long as it transmits light emitted from the light emitting element. The term “translucent” 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 even more preferably 80% or more. Say things. Silicone resin, epoxy resin, phenol resin, polycarbonate resin, acrylic resin, or modified resin thereof can be used for the first base material. Glass may be used. Among them, silicone resins and modified silicone resins are preferable because of their excellent heat resistance and light resistance. Specific silicone resins include dimethyl silicone resin,
Phenyl-methylsilicone resins and diphenylsilicone resins can be mentioned. In addition, the "modified resin" in this specification shall include a hybrid resin.

The first base material may contain various diffusion particles in the above resin or glass. Diffusion particles include silicon oxide, aluminum oxide, zirconium oxide, zinc oxide, and the like. Diffusion particles can be used singly or in combination of two or more of these. Silicon oxide, which has a small coefficient of thermal expansion, is particularly preferred. Moreover, by using nanoparticles as diffusion particles, it is possible to increase scattering of light emitted from the light emitting element and reduce the amount of wavelength conversion particles used.

(Light guide member 50)
The light guide member is a member that adheres the light emitting element and the translucent member and guides the light from the light emitting element to the translucent member. Examples of the base material of the light guide member include silicone resins, epoxy resins, phenol resins, polycarbonate resins, acrylic resins, and modified resins thereof. Among them, silicone resins and modified silicone resins are preferable because of their excellent heat resistance and light resistance. Specific silicone resins include dimethyl silicone resin, phenyl-methyl silicone resin,
A diphenyl silicone resin may be mentioned. Also, 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 reflective member preferably has a light reflectance of 70% or more, more preferably 80% or more, and more preferably 90% or more at the emission peak wavelength of the light emitting element. One is even more preferable. Furthermore, the reflective 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 reflective member can be formed by transfer molding, injection molding, compression molding, potting, or the like.

(Base material of reflective member)
A resin can be used as the base material of the reflecting member, such as silicone resin, epoxy resin,
Phenolic resins, polycarbonate resins, acrylic resins, or modified resins thereof may be used. Among them, silicone resins and modified silicone resins are excellent in heat resistance and light resistance,
preferable. Specific silicone resins include dimethylsilicone resin, phenyl-methylsilicone resin, and diphenylsilicone resin.

(white pigment)
White pigments include titanium oxide, zinc oxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, calcium carbonate, calcium hydroxide, calcium silicate, magnesium silicate,
One of barium titanate, barium sulfate, aluminum hydroxide, aluminum oxide, zirconium oxide, and silicon oxide can be used alone, or two or more of these can be used in combination. The shape of the white pigment can be selected as appropriate, and may be amorphous or crushed, but a spherical shape is preferable from the viewpoint of fluidity. The particle size of the white pigment is, for example, approximately 0.1 μm or more and 0.5 μm or less. The content of the white pigment in the reflective member can be selected as appropriate, but from the viewpoint of light reflectivity and viscosity in the 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%. % or more and 60 wt% or less is even more preferable. It should be noted that "wt%" is percent by weight and represents the ratio of the weight of the material to the total weight of the reflective member.

(Second wavelength conversion member 32)
A material similar to that of the first wavelength conversion member can be used for the second wavelength conversion member.

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

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

(Base material 11)
The base material 11 can be configured using an insulating member such as resin or fiber-reinforced resin, ceramics, or glass. Examples of resins or fiber-reinforced resins include epoxy, glass epoxy, bismaleimide triazine (BT), and polyimide. Examples of ceramics include aluminum oxide, aluminum nitride, zirconium oxide, zirconium nitride, titanium oxide, titanium nitride, and mixtures thereof. Among these base materials, it is particularly preferable to use a base material having physical properties close to the coefficient of linear expansion of the light emitting device. Although the lower limit of the thickness of the base material can be selected as appropriate, it is preferably 0.05 mm or more, more preferably 0.2 mm or more, from the viewpoint of the strength of the base material. In addition, the upper limit of the thickness of the base material is preferably 0.5 mm or less from the viewpoint of the thickness (depth) of the light emitting device.
. It is more preferably 4 mm or less.

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

(Via 15)
The via 15 is provided in a hole penetrating the front surface and the back surface of the base material 11, and is a member for electrically connecting the first wiring and the second wiring. The via 15 is the fourth wiring 1 covering the surface of the through hole of the base material.
51 and a filling member 152 filled in 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. A conductive member or an insulating member may be used for the filling member 152 .

(insulating film 18)
The insulating film 18 is a member that secures insulation on the rear surface and prevents short circuits. The insulating film may be formed of any material used in the relevant field. For example, thermosetting resins or thermoplastic resins may 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 bumps of gold, silver, copper, etc.;
Any one of copper-based, tin-silver-based, gold-tin-based solders, and brazing materials such as low-melting-point metals can be used.

Light-emitting devices according to one embodiment of the present invention include backlight devices for liquid crystal displays, various lighting fixtures, large displays, various display devices for advertisements and destination information, projector devices, digital video cameras, facsimiles, and copiers. , an image reading device such as a scanner.

1000, 1000A, 1000B, 1000C light emitting device 10 substrate 11 base material 12 first wiring 13 second wiring 14 third wiring 15 via
151 fourth wiring
152 Filling Member 16 Hollow 18 Insulating Film 20 Light Emitting Element 31 First Wavelength Conversion Member 32 Second Wavelength Conversion Member 33 Covering Member 34 Film 40 Reflecting Member 50 Light Guide Member 60 Conductive Adhesive Member

Claims (6)

a light emitting element having a first surface, a second surface located opposite to the first surface, and a first side surface located between the first surface and the second surface;
a light guide member covering the first side surface of the light emitting element;
a first wavelength converting member positioned above the first surface and including a first base material and first wavelength converting particles that are manganese-activated fluoride phosphors;
a second wavelength conversion member positioned between the light emitting element and the first wavelength conversion member and including a second base material and second wavelength conversion particles having a shorter peak wavelength than the first wavelength conversion particles;
a reflecting member in contact with at least part of the light emitting element;
with
The second wavelength conversion member has a third surface facing the first surface, a fourth surface located opposite to the third surface, and located between the third surface and the fourth surface. a second side;
The first wavelength conversion member has a fifth surface facing the fourth surface, a sixth surface opposite to the fifth surface, and a position between the fifth surface and the sixth surface. a third side;
the reflecting member covers the light guide member, the second side surface of the second wavelength conversion member, and the third side surface of the first wavelength conversion member;
The thickness of the first wavelength conversion member , which is the distance between the fifth surface and the sixth surface, 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 median particle size of the first wavelength-converting particles is 4 μm or more and 12 μm or less;
The first wavelength conversion particles are 60% by weight or more and 75% by weight or less with respect to the total weight of the first wavelength conversion member,
The light-emitting device , wherein the thickness of the second wavelength conversion member , which is the distance between the third surface and the fourth surface, is half or less of the thickness of the first wavelength conversion member. The light-emitting device according to claim 1 , wherein the average particle size of the first wavelength-converting particles is smaller than the average particle size of the second wavelength-converting particles. The light-emitting device according to claim 1 or 2 , wherein the second wavelength-converting particles are β-sialon-based phosphors. The light-emitting device according to any one of claims 1 to 3, wherein the second wavelength conversion member has a thickness of 20 µm or more and 60 µm or less. The light emitting device according to any one of claims 1 to 4 , further comprising a covering member covering said sixth surface of said first wavelength converting member. The light-emitting device according to any one of claims 1 to 5, wherein the standard deviation of the particle size distribution of the first wavelength-converting particles based on the volume of the first wavelength-converting member is 0.3 µm or less.

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