JP2010016273A - Semiconductor light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting device that further reduces color unevenness, and prevents the degradation of efficiency in excitation of phosphor and in light extraction. <P>SOLUTION: The LED lamp 10 (semiconductor light-emitting device) has an LED chip 1, phosphor layers 5, 6 which are provided at least in two layers in a light emission direction (B2 direction) side of the LED chip 1 and include a phosphor which converts a wavelength of light emitted from the LED chip 1 and an Al-based thin film-like light diffusion part 7 disposed to be held between the phosphor layers 5, 6. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a semiconductor light emitting device, and more particularly to a semiconductor light emitting device including a semiconductor light emitting element, a wavelength conversion unit, and a light diffusion unit.

  A light emitting diode (LED) is small, has characteristics such as low power consumption and long life, and can emit light in a wavelength region from infrared light including visible light to ultraviolet light. Already put into practical use as an alternative to small bulbs (such as miniature bulbs and jujube bulbs) and as backlights for liquid crystal displays. Furthermore, the use as a light source for general illumination replacing incandescent lamps and fluorescent lamps is expected due to the high efficiency of light emission of LEDs and the low cost during manufacture.

  When white LEDs used for general illumination are combined with blue LEDs or ultraviolet LEDs and phosphors, some of the light emitted from the LEDs excites the phosphors to emit red or green light. The colored light of the LED itself and the colored light of the phosphor are mixed to emit white light.

  Here, the light emitted from the LED chip has directivity, and the color tone of the light emission observation surface of the white LED varies greatly depending on the viewing angle. For example, when a blue LED having a strong output peak in the vertical direction of the LED chip and a yellow light emitting phosphor are combined, the LED chip exhibits a slightly bluish white in the direction perpendicular to the LED chip, while the LED chip has a slight inclination in the diagonal direction. There tends to be a yellowish white color. Therefore, it is necessary to reduce the occurrence of such color unevenness in the white LED applied for general illumination.

  For this reason, conventionally, attempts have been made to reduce color unevenness by mixing a diffusing material into a transparent resin interposed between an LED chip and a phosphor. However, since the diffusing material is not uniformly dispersed in the transparent resin, there is a disadvantage in that color unevenness is caused due to a local density difference in the transparent resin of the diffusing material. Further, when the diffusing material and the phosphor are mixed in the transparent resin at the same time, the color unevenness becomes more prominent.

  Therefore, conventionally, there has been proposed a light emitting diode device in which an LED chip, a resin containing a phosphor and a resin containing a diffusing material are individually formed and stacked on the LED chip (see, for example, Patent Document 1). .

  Patent Document 1 discloses a light emitting diode device in which a phosphor sheet including a light diffusion layer and a phosphor layer is provided on a light emitting direction side of an LED chip via a transparent layer. In this light emitting diode device, three types of cross-sectional structures are proposed in which the light diffusion layer is disposed on either the lower surface or the upper surface of the phosphor layer, or on both the lower surface and the upper surface of the phosphor layer. Yes. When light from the LED chip passes through the phosphor sheet having each type of cross-sectional structure, incident light is diffused and emitted from the light diffusion layer, and the phosphor layer excites the phosphor to make visible light. By emitting light, white light is emitted from the light emission observation surface. This light-emitting diode device is configured to be able to reduce the color unevenness of white light by appropriately adjusting the ratio of the diffused light of the LED light by the light diffusion layer and the ratio of the excitation light of the phosphor. In addition, the light incident on the light diffusion layer is diffused in a direction away from the LED chip, and is also diffused in a direction returning to the LED chip (light source).

JP 2007-67204 A

  However, in the light emitting diode device disclosed in Patent Document 1, when the light diffusion layer is disposed only on the lower surface of the phosphor layer, the light diffused toward the phosphor layer among the diffused light from the light diffusion layer. Are only incident on the phosphor layer. In addition, when the light diffusion layer is disposed only on the upper surface of the phosphor layer, a part of the excitation light from the phosphor is returned to the phosphor layer by the light diffusion layer. In the state where only a part of the diffused light component is incident on the phosphor layer, the amount of light incident on the phosphor layer is reduced and the phosphor is not sufficiently excited, so that the excitation efficiency of the phosphor is lowered. . In addition, in a state where a part of the excitation light of the phosphor is returned to the phosphor layer by the light diffusion layer, the amount of light in the direction of the light emission observation surface is reduced, so that there is a problem that the light extraction efficiency is lowered. Further, even when the light diffusion layer is disposed on both sides of the phosphor layer, when the emitted light of the LED chip enters the phosphor layer from the light diffusion layer, and from the phosphor layer to the light diffusion layer Since the same phenomenon as described above occurs in both states when the light enters the light source, there is a problem that both the excitation efficiency of the phosphor and the light extraction efficiency are lowered. Another problem is that it is difficult to suppress color unevenness that occurs on the light emission observation surface of the light emitting diode device due to a decrease in the excitation efficiency of the phosphor and a decrease in the light extraction efficiency.

  The present invention has been made to solve the above-described problems, and one object of the present invention is to further reduce color unevenness, and to excite phosphors and to extract light. It is an object of the present invention to provide a semiconductor light emitting device capable of suppressing a decrease in efficiency.

Means for Solving the Problems and Effects of the Invention

  In order to achieve the above object, a semiconductor light emitting device according to one aspect of the present invention includes a semiconductor light emitting element and at least two layers provided on the light emitting direction side of the semiconductor light emitting element, and the light emitted from the semiconductor light emitting element. A wavelength conversion unit including a phosphor that converts the wavelength of the light, and a light diffusion unit disposed so as to be sandwiched between the wavelength conversion units.

  In the semiconductor light emitting device according to one aspect of the present invention, as described above, by including the wavelength conversion unit provided with at least two layers and the light diffusion unit arranged so as to be sandwiched between the wavelength conversion units. For example, out of the light transmitted from the semiconductor light emitting element through the first wavelength converter, the light diffuser adjacent to the first wavelength converter diffuses away from the first wavelength converter. The incident light is incident on the wavelength conversion unit of the second layer, while the light diffused in the direction returning to the wavelength conversion unit of the first layer by the light diffusion unit adjacent to the wavelength conversion unit of the first layer is Since the light is also incident on the first wavelength conversion unit, the diffused light from the light diffusion unit can excite each phosphor in the two wavelength conversion units. Thereby, the fall of the excitation efficiency of fluorescent substance is suppressed. In addition, both the light excited in the first wavelength conversion unit and the light excited in the second wavelength conversion unit are emitted toward the outside of the semiconductor light emitting device. Thereby, the fall of the extraction efficiency of the light radiate | emitted from a semiconductor light-emitting device is suppressed. As described above, the phosphor excitation efficiency and the light extraction efficiency can be suppressed from decreasing. In addition, since the phosphor excitation efficiency and the light extraction efficiency are suppressed from decreasing, it is possible to further reduce the occurrence of color unevenness in the light emitted from the semiconductor light emitting device.

  In the semiconductor light-emitting device according to the above aspect, preferably, the light diffusing portion is in a state where the light diffusing portions made of metal are distributed in an island shape in plan view, or adjacent light diffusing portions are light diffusing portions. A thin-film light diffusing portion that is partially joined at the outer edge portion of the substrate and formed in a net shape. With this configuration, when the light from the semiconductor light emitting element passes through the thin film-shaped light diffusion portion formed in the island shape or the net shape, it is diffused by the light diffusion portion and is opposite to the incident surface and the incident surface of the thin film. Since it becomes easy to discharge | release from both of the side surfaces, it can suppress more that the light quantity of the diffused light by a light-diffusion part falls.

  In the semiconductor light emitting device according to the above aspect, preferably, the light diffusion portion is provided in two or more layers. If comprised in this way, since the spreading | diffusion of a diffused light can be repeated with the light-diffusion part which consists of several layers, sufficient diffusion effect can be acquired.

  In the configuration in which the light diffusing portion is provided in two or more layers, preferably, the light diffusing portion includes a thin-film light diffusing portion made of a metal formed in an island-like distribution when seen in a plan view. The light diffusing portion disposed on the side closer to the semiconductor light emitting element and the light diffusing portion disposed on the side far from the semiconductor light emitting element have an average particle diameter or an island-shaped portion with respect to the entire plane area of the light diffusing portion. At least one of the proportions of the flat area is different. With this configuration, for example, the average particle diameter of the light diffusing part on the side close to the semiconductor light emitting element or the ratio of the flat area of the island-like part to the total flat area of the light diffusing part is far from the semiconductor light emitting element If the average particle diameter of the light diffusing part or the ratio of the flat area of the island-shaped part to the total flat area of the light diffusing part is smaller, first, the emitted light of the semiconductor light emitting element is the average on the side close to the semiconductor light emitting element Since the light diffusing part transmits a small amount of diffusion in the light diffusing part with a small proportion of the area of the island-like part relative to the particle size or the total area of the light diffusing part, the phosphor of the adjacent wavelength converting part is actively excited Color development is promoted. Thereafter, the sufficiently colored light is actively diffused in the light diffusion part where the average particle diameter on the side far from the semiconductor light emitting element or the ratio of the flat area of the island-like part to the total flat area of the light diffusion part is large. Both color development and light diffusion of the phosphor are effectively performed. As a result, the color unevenness of the combined light of the semiconductor light emitting element and the phosphor reaching the outside of the semiconductor light emitting device can be more effectively reduced.

  In addition, the average grain size of the light diffusion portion on the side close to the semiconductor light emitting element or the ratio of the flat area of the island-shaped portion to the total plane area of the light diffusion portion is the average grain of the light diffusion portion on the side far from the semiconductor light emitting element. When the diameter or the ratio of the area of the island-shaped portion to the total area of the light diffusing portion is larger than the proportion of the area of the island-shaped portion, first, the emitted light of the semiconductor light emitting element is actively diffused in the light diffusing portion on the side close to the semiconductor light emitting element . After that, the sufficiently diffused light actively excites the phosphor in the wavelength conversion part far from the semiconductor light emitting element to promote the color development of the phosphor, so that both the light diffusion and the color development of the phosphor are effective. Done. Then, the light in this state is transmitted through the light diffusing portion with a small diffusion ratio in which the average particle diameter on the side far from the semiconductor light emitting element or the ratio of the flat area of the island-like portion to the total flat area of the light diffusing portion is small. As a result, the color unevenness of the combined light of the semiconductor light emitting element and the phosphor reaching the outside of the semiconductor light emitting device can be more effectively reduced.

  In addition, when the light emitted from the semiconductor light emitting element is ultraviolet light, there is a demand to suppress the ultraviolet light from being emitted to the outside of the semiconductor light emitting device. The ratio of the area of the island-like portion to the diameter or the total area of the light diffusion portion is the average particle diameter of the light diffusion portion far from the semiconductor light emitting element or When the area occupied by the flat area is larger than that, the ultraviolet light is actively diffused by the light diffusing section on the side close to the semiconductor light emitting element, so that the ultraviolet light is easily prevented from being emitted to the outside of the semiconductor light emitting device. Can do.

  In the semiconductor light-emitting device according to the aforementioned aspect, the light diffusion part preferably includes a light diffusion layer formed so as to cover the surface of the wavelength conversion part in a continuous film state. If comprised in this way, all the light which permeate | transmitted the wavelength conversion part from the semiconductor light-emitting element will inject into the part of the light-diffusion layer formed in the state of a continuous film | membrane. Thereby, the light which injects into a light-diffusion part can be diffused more reliably.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a cross-sectional view illustrating the structure of an LED lamp according to a first embodiment of the present invention. 2-6 is a figure for demonstrating the structure of the LED lamp by 1st Embodiment shown in FIG. 1, respectively. First, the structure of the LED lamp 10 according to the first embodiment will be described with reference to FIGS. In the first embodiment, a case where the present invention is applied to an LED lamp which is an example of a semiconductor light emitting device will be described.

  In the bullet-type LED lamp 10 according to the first embodiment of the present invention, as shown in FIG. 1, the LED chip 1 that emits blue light having an emission wavelength peak of about 420 nm to about 480 nm is made of solder or the like (not shown). Is fixed to the bottom surface of the recess of the metal lead frame 2. As a result, the n-side electrode 15 (see FIG. 6) of the LED chip 1 is electrically connected to the lead frame 2. Further, the inner side surface 2a of the concave portion of the lead frame 2 is finished in a mirror state so that the light emitted from the LED chip 1 is easily reflected, and is configured to function as a light reflecting portion. One end of the lead 3 is attached to the lead frame 2. Further, the p-side translucent electrode 16 (see FIG. 6) of the LED chip 1 is electrically connected to one end of the lead 4 via a metal wire (not shown). The LED chip 1 is an example of the “semiconductor light emitting element” in the present invention.

  Further, in the concave portion of the lead frame 2, a phosphor layer 5 made of silicon resin covering the LED chip 1 disposed on the bottom surface side (arrow B1 direction side), and a phosphor layer 5 disposed on the arrow B2 direction side. And a phosphor layer 6 made of silicon resin. The phosphor layers 5 and 6 are examples of the “wavelength converter” in the present invention. The phosphor layers 5 and 6 both have a thickness of several hundred μm or more and about 1 mm or less. The phosphor layers 5 and 6 are mixed with a phosphor that develops yellow color.

  Here, in the first embodiment, as shown in FIG. 1, a thin-film light diffusion portion 7 made of Al having a thickness of several nm is formed between the phosphor layer 5 and the phosphor layer 6. . The light diffusing portion 7 is formed over the entire surface (upper surface) of the phosphor layer 5 and is curved along the surface shape of the phosphor layer 5. Moreover, the thickness (several nm) of the light diffusion part 7 is formed sufficiently smaller than the thicknesses of the phosphor layer 5 and the phosphor layer 6 (several hundred μm or more and about 1 mm or less). In FIG. 1, for convenience of the drawing, a state in which the light diffusion portion 7 is formed by expressing Al particles in a plurality of circular shapes is shown.

  In the first embodiment, as shown in FIG. 2, the Al thin film that is the light diffusion portion 7 is formed in a state of being distributed in an island shape on the phosphor layer 5 (see FIG. 1) when seen in a plan view. For example, when the Al thin film has a thickness of about 3 nm, it is not a continuous film. That is, the Al thin film having a thickness of about 3 nm is formed in a plurality of islands distributed in the fine recesses of the phosphor layer 5 (see FIG. 1). When the Al island has a substantially circular shape, the average particle diameter is preferably formed in the range of several tens of nm to several μm, and more preferably about 100 nm or less. When the Al island has a distorted island shape, it preferably has a width of several tens of nm to several μm in at least one direction, and more preferably about 100 nm or less.

  In addition, the light diffusion portion 7 preferably has a total plane area of Al islands of about 70% or less of the total plane area of the light diffusion portion 7 in plan view. More preferably, it is about 5% or more and about 70% or less of the plane area. In addition, by using a scanning electron microscope (SEM), a transmission electron microscope (TEM), etc., the state of the Al thin film island is observed to measure the particle size and calculate the ratio of the flat area of the Al island. Is possible. Furthermore, when the average particle diameter is several μm, it is possible to observe the Al thin film and measure the particle diameter using an optical microscope.

  Further, as shown in FIG. 3, as the thickness of the Al thin film increases (about 6 nm or more and about 50 nm or less), the flat area of each island increases and the interval between adjacent islands begins to narrow. Note that the thickness of the Al thin film is preferably about 30 nm or less, and more preferably about 10 nm or less.

  As shown in FIG. 4, when the thickness of the Al thin film is further increased (about 100 nm or more and about 1 μm or less), in addition to the part where the distance between adjacent islands is small, the outer edge part of adjacent islands is partially Join. As a result, the Al thin film is formed in a net-like state and approaches a continuous film state. When the Al thin film is formed in a net shape, the average interval between the holes of adjacent nets (the width of the portion where the Al metal is formed) is formed in the range of several tens nm to several μm. More preferably, the average spacing between adjacent mesh holes is about 100 nm or less.

  Further, as shown in FIG. 5, in the thin film state where the thickness of the Al film is small (several nm), each island constituting the light diffusing portion 7 is formed in a fine concave portion of the phosphor layer 5, so The bottom (the side in contact with the phosphor layer 5) is formed in a curved shape along the shape of the fine recesses of the phosphor layer 5. Thereby, the emitted light that passes through the phosphor layer 5 in the B2 direction and reaches the light diffusion portion 7 is configured to be easily diffused by the curved surface shape of the bottom portion of each island.

  In addition, as shown in FIG. 1, a bullet-shaped seal made of silicon resin is used to seal the lead frame 2 including the LED chip 1, the metal wire (not shown), and the connecting portion between the wire and the lead 4. A stop 8 is formed. The other ends of the leads 3 and 4 are exposed from the sealing portion 8 in the B1 direction.

  As shown in FIG. 6, the LED chip 1 includes a substrate 11 made of GaN, sapphire, etc., an n-type cladding layer 12 made of GaN, AlGaN, InGaN, or the like, a light emitting layer 13, GaN, AlGaN, or InGaN. A p-type cladding layer 14 is formed in this order. An n-side electrode 15 is formed on the lower surface of the substrate 11, and a p-side translucent electrode 16 made of ITO is formed on the p-type cladding layer 14. In the LED chip 1, the lower surface of the n-side electrode 15 is fixed to the bottom surface of the recess of the lead frame 2 via solder. Further, one end of a wire connected to the lead 4 (see FIG. 1) is bonded onto the p-side translucent electrode 16.

  The LED chip 1 has a length in the range of about 200 μm to about 1000 μm in the A direction (plane direction), and has a thickness in the range of about 100 μm to about 300 μm in the B direction (height direction). Is formed. Thereby, the area of the side surface of the LED chip 1 is smaller than the plane area of the upper surface. Therefore, the emitted light of the LED chip 1 has a directivity mainly emitted from the upper surface (p-side translucent electrode 16) side of the LED chip 1 in a direction (arrow B2 direction) perpendicular to the surface. .

  In the LED lamp 10, as shown in FIG. 1, the blue light emitted from the LED chip 1 in the B2 direction first enters the phosphor layer 5 and causes the phosphor to emit yellow light. As a result, the blue light of the LED chip 1 and the yellow light of the phosphor layer 5 are mixed and enter the light diffusion portion 7 in the B2 direction. Then, the incident light is further diffused in the B2 direction by the island-shaped Al thin film, and enters the phosphor layer 6 to cause the phosphor to emit yellow light. Thereafter, the blue light of the LED chip 1 that has passed through the phosphor layer 5 and the light diffusing portion 7 and the yellow light of the phosphor layer 6 are mixed to form white light, which is transmitted through the sealing portion 8 in the B2 direction to the outside. Emitted. In addition, the light diffused in the B1 direction in the light diffusing unit 7 (see FIG. 5) is incident again on the phosphor layer 5 to cause the phosphor to emit yellow light. In the first embodiment, the above operation is repeated, so that white light with reduced color unevenness is emitted from the LED lamp 10 in the B2 direction. In the present specification, “white” means “appears white to human eyes”.

  7 and 8 are views for explaining a manufacturing process of the LED lamp according to the first embodiment shown in FIG. Next, with reference to FIG. 1 and FIGS. 6-8, the manufacturing process of the LED lamp 10 by 1st Embodiment is demonstrated.

  First, the n-type cladding layer 12, the light emitting layer 13, and the p-type cladding layer 14 are formed in this order on the upper surface of the substrate 11 by MOCVD. Thereafter, the p-side translucent electrode 16 made of ITO is formed on the p-type cladding layer 14 by using a vacuum deposition method. Further, after polishing the substrate 11 to a predetermined thickness, the n-side electrode 15 is formed on the lower surface of the substrate 11 by using a vacuum deposition method. Thereafter, by dividing the element, the LED chip 1 formed into chips as shown in FIG. 6 is formed.

  Next, as shown in FIG. 7, the lower surface (n-side electrode 15) of the LED chip 1 is fixed to the bottom surface of the recess of the lead frame 2 by soldering. Thereafter, the p-side translucent electrode 16 and the lead 4 are connected by a wire (not shown). Then, the phosphor layer 5 is formed by injecting silicon resin into the recesses of the lead frame 2 so as to cover the LED chip 1 and curing the silicon resin by heating. At this time, the phosphor layer 5 is formed so that the surface (upper surface) is slightly curved in the B2 direction. Thereafter, an Al thin film having a thickness of several nanometers is formed on the surface of the phosphor layer 5 by using a vacuum deposition method to form the light diffusion portion 7. Subsequently, as shown in FIG. 8, the phosphor layer 6 is formed by injecting silicon resin into the concave portion of the lead frame 2 and curing the silicon resin by heating so as to cover the light diffusion portion 7 made of an Al thin film. . The phosphor layer 6 is formed in a flat surface shape so that the surface (upper surface) is at the same position as the upper end surface of the lead frame 2.

  Thereafter, the lead frame 2 including the LED chip 1 is inserted into a shell-shaped mold filled with silicon resin, and the silicon resin is cured by heating to form a shell-shaped sealing portion 8 (see FIG. 1). At this time, the lead frame 2 (lead 3) including the LED chip 1, the metal wire (not shown), and the connection portion between the wire and the lead 4 are sealed by the sealing portion 8. Finally, the LED lamp 10 according to the first embodiment shown in FIG. 1 is formed by removing the sealing portion 8 from the mold.

  In the first embodiment, as described above, the phosphor layers 5 and 6 and the thin-film light diffusion portion 7 made of Al arranged so as to be sandwiched between the phosphor layers 5 and 6 are provided. For example, out of the light transmitted from the LED chip 1 through the first phosphor layer 5, it is diffused in the direction away from the phosphor layer 5 (B2 direction) by the light diffusion portion 7 adjacent to the phosphor layer 5. While light is incident on the second phosphor layer 6, the light diffused in the direction of returning to the first phosphor layer 5 (B1 direction) by the light diffusing unit 7 is also incident on the phosphor layer 5. Therefore, the diffused light from the light diffusing unit 7 can excite each phosphor in the phosphor layers 5 and 6. As a result, both the excitation light in the phosphor layer 5 and the excitation light (yellow light) in the phosphor layer 6 are in the state of white light synthesized with the blue light emitted from the LED chip 1 and outside the LED lamp 10 (B2 direction). ). As a result, it is possible to suppress the phosphor excitation efficiency and the light extraction efficiency in the LED lamp 10 from decreasing. Moreover, since it is suppressed that the excitation efficiency of a fluorescent substance and the light extraction efficiency fall, it can further reduce that the color nonuniformity arises in the emitted light from the LED lamp 10. FIG.

  In the first embodiment, the thin-film light diffusing portion 7 made of Al is in a state in which Al is distributed in an island shape when viewed in plan (see FIGS. 2 and 3), or adjacent Al islands. A thin light diffusion portion 7 in which the light from the LED chip 1 is formed in an island shape or a net shape by forming the net so as to form a net shape (see FIG. 4). Is diffused by the light diffusing unit 7 and is easily emitted from both the incident surface of the thin film and the surface opposite to the incident surface to the phosphor layers 5 and 6. It can suppress more that the light quantity of light falls.

(Modification of the first embodiment)
FIG. 9 is a cross-sectional view showing a detailed structure of a light emitting part of an LED lamp according to a modification of the first embodiment of the present invention. Referring to FIG. 9, in the LED lamp 20 according to the modification of the first embodiment, unlike the first embodiment, two light diffusion portions 24 and 25 are provided between the three phosphor layers 21 to 23. The case where it is formed will be described.

  Here, in the LED lamp 20 according to the modification of the first embodiment, as shown in FIG. 9, phosphor layers 21, 22 and 23 made of silicon resin covering the LED chip 1 emitting blue light are formed in this order. ing. The phosphor layers 21, 22, and 23 are examples of the “wavelength conversion unit” in the present invention. The phosphor layers 21, 22 and 23 are mixed with a phosphor that develops a yellow color. Further, the phosphor layers 21, 22 and 23 are laminated in the recesses of the lead frame 2 so as to have a substantially uniform thickness in the depth direction (B1 direction). FIG. 9 shows a detailed structure around the light emitting portion including the lead frame 2 in the LED lamp 20 having the same outer shape as the LED lamp 10 of the first embodiment.

  In the modification of the first embodiment, a thin-film light diffusion portion 24 made of Al having a thickness of several nm is formed between the phosphor layer 21 and the phosphor layer 22, and the phosphor layer 22. A thin-film light diffusion portion 25 made of Al having a thickness of several nanometers is formed between the phosphor layer 23 and the phosphor layer 23. Further, the thicknesses (several nm) of the light diffusion portions 24 and 25 are formed sufficiently smaller than the thicknesses of the phosphor layer 21, the phosphor layer 22, and the phosphor layer 23. In FIG. 9, for the convenience of the drawing, the light diffusion portions 24 and 25 are formed by expressing Al particles in a plurality of circular shapes.

  As in the modification of the first embodiment, when two layers of light diffusion portions (light diffusion portions 24 and 25) are provided, when only one layer of light diffusion portion is provided (first embodiment). In the light diffusing portion 7, the total plane area of the Al islands is preferably about 5% or more and about 70% or less of the total plane area of the light diffusing portion 7). The total plane area of the Al islands is about 5% or less of the total plane area of the light diffusion portion 24, and the total plane area of the Al islands of the light diffusion portion 25 is the total plane area of the light diffusion portion 25. You may comprise the light-diffusion parts 24 and 25, respectively so that it may be about 5% or less of them. However, it is preferable that the total of the ratio of the total plane area of the Al islands to the total plane area of each layer is secured about 5% or more. For example, the total plane area of the Al islands in the light diffusion portion 24 or 25 is preferably about 2.5% or more of the total plane area of the light diffusion portion 24 or 25. When the total plane area of the Al islands in the light diffusion portion 24 is about 2% of the total plane area, the total plane area of the Al islands in the light diffusion portion 25 is about 3% or more of the total plane area. Preferably, the light diffusion portion 25 is formed. Further, when the light diffusing portions 24 and 25 are viewed individually, the total plane area of the Al islands with respect to the total plane area of the light diffusing portion is the same as in the case of the light diffusing portion 7 consisting of a single layer in the first embodiment. Is preferably about 70% or less, more preferably about 50% or less. In addition, the total of the said ratio of the island of Al in each layer (light-diffusion part 24 and 25) may be 100% or more.

  The remaining structure and manufacturing process of the LED lamp 20 according to the modification of the first embodiment are the same as those of the first embodiment.

  In the modification of the first embodiment, as described above, the thin-film light diffusion portions 24 and 25 made of Al are provided between the phosphor layers 21 to 23, respectively, so that the light made up of a plurality of layers. Since the diffusing action of the diffused light can be repeated by the diffusing portions 24 and 25, a sufficient diffusing effect can be obtained.

(Second Embodiment)
FIG. 10 is a sectional view showing a detailed structure of the LED lamp according to the second embodiment of the present invention. With reference to FIG. 10, in the LED lamp 30 according to the second embodiment, a case where flat sheet-like phosphor layers 31 and 32 are used above the LED chip 1 will be described, unlike the first embodiment.

  Here, in the LED lamp 30 according to the second embodiment, as shown in FIG. 10, a transmissive portion made of a transparent silicon resin that covers the LED chip 1 that emits blue light so as to completely fill the concave portion of the lead frame 2. 9 is formed. And on the flat upper surface of the transmission part 9, the sheet-like fluorescent substance layer 31 and the fluorescent substance layer 32 which consist of silicon resins are formed in this order. The phosphor layers 31 and 32 are examples of the “wavelength converter” in the present invention. The phosphor layers 31 and 32 are mixed with a phosphor that develops yellow color.

  In the second embodiment, a thin-film light diffusion portion 33 made of Al having a thickness of several nanometers is formed between the phosphor layer 31 and the phosphor layer 32. In addition, the thickness (several nm) of the light-diffusion part 33 is formed sufficiently smaller than the thickness of the phosphor layer 31 and the phosphor layer 32. In addition, the other structure of the LED lamp 30 by 2nd Embodiment is the same as that of the said 1st Embodiment.

  Next, with reference to FIG. 6 and FIG. 10, the manufacturing process of the LED lamp 30 by 2nd Embodiment is demonstrated.

  First, the LED chip 1 (see FIG. 6) that emits blue light is formed by a manufacturing process similar to that of the first embodiment, and is fixed to the bottom surface of the concave portion of the lead frame 2 (see FIG. 6). I do. Then, as shown in FIG. 10, a silicone resin is injected into the recess of the lead frame 2 so as to cover the LED chip 1, and the silicone resin is cured by heating to form a transmission portion 9. The transmitting portion 9 is formed in a flat surface at the same position as the upper end surface of the lead frame 2 on the surface (upper surface).

  Thereafter, as shown in FIG. 10, a sheet-like phosphor layer 31 is bonded onto the flat upper surface of the transmission part 9. Thereafter, an Al thin film having a thickness of several nanometers is formed on the surface of the phosphor layer 31 by using a vacuum deposition method to form the light diffusion portion 33. Further, a sheet-like phosphor layer 32 is bonded onto the surface of the light diffusion portion 33. Thereafter, the LED lamp 30 according to the second embodiment is formed by a manufacturing process similar to that of the first embodiment.

  In the second embodiment, as described above, the phosphor layers 31 and 32 and the thin-film light diffusion portion 33 made of Al arranged so as to be sandwiched between the phosphor layers 31 and 31 are provided. For example, out of the light transmitted from the LED chip 1 through the first phosphor layer 31, it is diffused in the direction away from the phosphor layer 31 (direction B2) by the light diffusion portion 33 adjacent to the phosphor layer 31. While light is incident on the second phosphor layer 32, the light diffused in the direction returning to the first phosphor layer 31 (B1 direction) by the light diffusion portion 33 is also incident on the phosphor layer 31. Therefore, the diffused light from the light diffusing section 33 can excite each phosphor in the phosphor layers 31 and 32. In addition, both the excitation light in the phosphor layer 31 and the excitation light in the phosphor layer 32 are emitted toward the outside of the LED lamp 30 (B2 direction). As a result, the phosphor excitation efficiency and the light extraction efficiency in the LED lamp 30 can be suppressed from decreasing. Moreover, since it is suppressed that the excitation efficiency of a fluorescent substance and the extraction efficiency of light fall, it can further reduce that the color nonuniformity arises in the emitted light from the LED lamp 30. FIG. The remaining effects of the second embodiment are similar to those of the aforementioned first embodiment.

(Modification of the second embodiment)
FIG. 11 is a cross-sectional view showing a detailed structure of a light emitting part of an LED lamp according to a modification of the second embodiment of the present invention. Referring to FIG. 11, in the LED lamp 40 according to the modification of the second embodiment, unlike the second embodiment, two layers of light diffusion portions 44 are disposed between the three layers of sheet-like phosphor layers 41 to 43. A case in which and 45 are formed will be described.

  Here, in the LED lamp 40 according to the modification of the second embodiment, as shown in FIG. 11, a sheet-like material made of silicon resin is formed on the flat upper surface of the transmissive portion 9 that completely fills the concave portion of the lead frame 2. The phosphor layers 41, 42 and 43 are formed in this order. The phosphor layers 41, 42, and 43 are examples of the “wavelength conversion unit” in the present invention. The phosphor layers 41, 42, and 43 are mixed with a phosphor that develops a yellow color. In addition, the phosphor layers 41, 42 and 43 are formed so as to have a substantially uniform thickness. FIG. 11 shows a detailed structure around the light emitting part including the lead frame 2 in the LED lamp 40 having the same outer shape as the LED lamp 30 of the second embodiment.

  In the modification of the second embodiment, a thin-film light diffusion portion 44 made of Al having a thickness of several nm is formed between the phosphor layer 41 and the phosphor layer 42, and the phosphor layer 42. A thin-film light diffusion portion 45 made of Al having a thickness of several nanometers is formed between the phosphor layer 43 and the phosphor layer 43. Moreover, the thickness (several nm) of the light-diffusion parts 44 and 45 is formed sufficiently smaller than the thickness of the fluorescent substance layers 41-43.

  The remaining structure and manufacturing process of the LED lamp 40 according to the modification of the second embodiment are the same as those of the second embodiment.

  In the modification of the second embodiment, as described above, a plurality of layers are provided by providing the thin-film light diffusion portions 44 and 45 made of Al between the layers of the sheet-like phosphor layers 41 to 43, respectively. Since the diffusion of the diffused light can be repeated by the light diffusing sections 44 and 45, a sufficient diffusion effect can be obtained.

(Third embodiment)
FIG. 12 is a cross-sectional view illustrating a detailed structure of a light emitting part of an LED lamp according to a third embodiment of the present invention. Referring to FIG. 12, in the LED lamp 50 according to the third embodiment, unlike the second embodiment, the average particle diameters of the light diffusion portions 51 and 52 sandwiched between the phosphor layers 41 to 43 are different from each other. Different cases will be described.

  Here, in the LED lamp 50 according to the third embodiment, as shown in FIG. 12, there is a thin-film light diffusion portion 51 made of Al having a thickness of several nm between the phosphor layer 41 and the phosphor layer 42. At the same time, a thin-film light diffusion portion 52 made of Al having a thickness of several nm is formed between the phosphor layer 42 and the phosphor layer 43. FIG. 12 shows a detailed structure around the light emitting portion including the lead frame 2 in the LED lamp 50 having the same outer shape as the LED lamp 30 of the second embodiment.

  At this time, in the third embodiment, the average particle diameter of the light diffusion portion 51 arranged on the side closer to the LED chip 1 is smaller than the average particle diameter of the light diffusion portion 52 arranged on the side far from the LED chip 1. It is comprised so that it may become. In FIG. 12, the Al particles are expressed in a plurality of circular shapes, and the light diffusion portions 51 and 52 are expressed so that the diameters of the circles are different to show the difference in average particle diameter. As a result, the emitted light from the LED chip 1 passes through the phosphor layer 41 and then passes through the light diffusion portion 51 having a small average particle diameter in a larger amount of light, thereby increasing the phosphor of the phosphor layer 42. Excitation of the phosphor layer 42 promotes the color development of the phosphor layer 42. The sufficiently colored light passes through the phosphor layer 43 in a state where it is actively diffused by the light diffusion part 52 having an average particle size larger than that of the light diffusion part 51 together with the light emitted from the LED chip 1. At this time, the phosphor of the phosphor layer 43 is colored so as to be emitted to the outside of the LED lamp 50.

  The remaining structure and manufacturing process of the LED lamp 50 according to the third embodiment are the same as those of the second embodiment.

  In 3rd Embodiment, as mentioned above, the average particle diameter of the light-diffusion part 51 arrange | positioned at the side near the LED chip 1 is larger than the average particle diameter of the light-diffusion part 52 arrange | positioned at the side far from the LED chip 1. First, the light emitted from the LED chip 1 that has passed through the phosphor layer 41 is transmitted through the light diffusing portion 51 having a small average particle diameter with a larger amount of light (in a less diffused state). Since the phosphor of the body layer 42 is actively excited, the color development of the phosphor layer 42 is promoted. Thereafter, the sufficiently colored light is actively diffused by the light diffusing portion 52 having a larger average particle diameter than the light diffusing portion 51, and further passes through the phosphor layer 43 and is emitted in the B2 direction. As a result, the excitation efficiency of the phosphor layer 42 can be increased, and the diffusion effect by the light diffusing unit 52 can be enhanced, so that the color unevenness of the light (white light) emitted to the outside of the LED lamp 50 can be more effectively reduced. Can be reduced.

(Fourth embodiment)
FIG. 13 is a cross-sectional view illustrating a detailed structure of a light emitting part of an LED lamp according to a fourth embodiment of the present invention. Referring to FIG. 13, in the LED lamp 60 according to the fourth embodiment, unlike the fourth embodiment, the average particle diameter of the light diffusion portion 61 sandwiched between the phosphor layers 41 and 42 is the phosphor layer. The case where it is larger than the average particle diameter of the light diffusion part 62 sandwiched between 42 and 43 will be described.

  Here, in the LED lamp 60 according to the fourth embodiment, as shown in FIG. 13, there is a thin-film light diffusion portion 61 made of Al having a thickness of several nm between the phosphor layer 41 and the phosphor layer 42. At the same time, a thin-film light diffusion portion 62 made of Al having a thickness of several nm is formed between the phosphor layer 42 and the phosphor layer 43. FIG. 13 shows the detailed structure around the light emitting part including the lead frame 2 in the LED lamp 60 having the same outer shape as the LED lamp 30 of the second embodiment.

  Under the present circumstances, in 4th Embodiment, the average particle diameter of the light-diffusion part 61 arrange | positioned at the side near the LED chip 1 is larger than the average particle diameter of the light-diffusion part 62 arrange | positioned at the side far from the LED chip 1. It is comprised so that it may become. In FIG. 13, the Al particles are expressed in a plurality of circular shapes, and the light diffusion portions 61 and 62 are expressed so that the diameters of the circles are different to show the difference in average particle diameter. Thereby, the emitted light of the LED chip 1 passes through the phosphor layer 42 in a state of being actively diffused by the light diffusion portion 61 having a large average particle diameter after passing through the phosphor layer 41. And the light which made the fluorescent substance of the fluorescent substance layer 42 color-development by the fully diffused light has the light quantity of light more than the light-diffusion part 62 whose average particle diameter is smaller than the light-diffusion part 61 with the emitted light of LED chip 1. By transmitting in the state, the phosphor of the phosphor layer 43 is actively excited. And it is comprised so that it may be radiate | emitted outside the LED lamp 60 in the state in which the color development of the fluorescent substance layer 43 was accelerated | stimulated.

  In addition, the other structure and manufacturing process of the LED lamp 60 by 4th Embodiment are the same as that of the said 3rd Embodiment.

  In 4th Embodiment, as mentioned above, the average particle diameter of the light-diffusion part 61 arrange | positioned at the side near the LED chip 1 is larger than the average particle diameter of the light-diffusion part 62 arrange | positioned at the side far from the LED chip 1. First, the light emitted from the LED chip 1 that has passed through the phosphor layer 41 is actively diffused by the light diffusion portion 61 having a large average particle diameter, and passes through the phosphor layer 42 to be emitted. Is done. Thereafter, the sufficiently diffused light passes through the light diffusing portion 62 having a smaller average particle diameter than the light diffusing portion 61 in the B2 direction with a larger amount of light (less diffused), and the phosphor of the phosphor layer 43 is flourished. The color of the phosphor layer 43 is promoted. As a result, the excitation efficiency of the phosphor layer 43 can be increased, and the diffusion effect by the light diffusing unit 61 can be increased, so that the color unevenness of the light (white light) emitted to the outside of the LED lamp 60 can be more effectively reduced. Can be reduced.

(Fifth embodiment)
FIG. 14 is a cross-sectional view illustrating a detailed structure of an LED lamp according to a fifth embodiment of the present invention. Referring to FIG. 14, in the LED lamp 70 according to the fifth embodiment, unlike the second embodiment, the case where the phosphor layers 71 and 72 sandwiching the light diffusion portion 33 are made of phosphors that emit different fluorescent colors will be described. To do.

  In the LED lamp 70 according to the fifth embodiment, as shown in FIG. 14, an LED chip 75 that emits ultraviolet light having an emission wavelength peak of about 350 nm to about 410 nm is fixed to the bottom surface of the recess of the metal lead frame 2. Yes. Further, a sheet-like phosphor layer 71 made of silicon resin and a phosphor layer 72 are formed in this order on the flat upper surface of the transparent portion 9 made of transparent silicon resin covering the LED chip 75. The phosphor layers 71 and 72 are examples of the “wavelength converter” in the present invention. The LED chip 75 is an example of the “semiconductor light emitting element” in the present invention.

  Here, in the fifth embodiment, the phosphor layer 71 contains a phosphor that develops blue color, and the phosphor layer 72 contains a phosphor that develops red color and a phosphor that develops yellow color. It is mixed. A thin-film light diffusion portion 73 made of Al having a thickness of several nm is formed between the phosphor layer 71 and the phosphor layer 72. The remaining structure and manufacturing process of the LED lamp 70 according to the fifth embodiment are the same as those of the second embodiment.

  In the fifth embodiment, as described above, by including the phosphor layers 71 and 72 and the thin-film light diffusion portion 73 made of Al arranged so as to be sandwiched between the phosphor layers 71 and 72. The emitted light (ultraviolet light) from the LED chip 75 excites each phosphor in the phosphor layers 71 and 72 by the diffused light from the light diffusion unit 73 by the same action as in the first embodiment. Then, both the excitation light (blue light) of the phosphor layer 71 and the excitation light (red light and yellow light) of the phosphor layer 72 are white light combined with the ultraviolet light emitted from the LED chip 75, and the LED lamp. Since the light is emitted to the outside of the LED 70, it is possible to suppress the phosphor excitation efficiency and the light extraction efficiency in the LED lamp 70 from being lowered. In addition, due to the above effect, it is possible to further reduce the occurrence of uneven color in the light emitted from the LED lamp 70.

(Sixth embodiment)
FIG. 15 is a sectional view showing a detailed structure of the LED array according to the sixth embodiment of the present invention. With reference to FIG. 6 and FIG. 15, in the LED array 80 according to the sixth embodiment, a case will be described in which a plurality of LED chips are arranged in one frame and different from the above embodiment. In the sixth embodiment, the case where the present invention is applied to an LED array which is an example of a semiconductor light emitting device will be described.

  In the LED array 80 according to the sixth embodiment, as shown in FIG. 15, LED chips 1 emitting blue light having an emission wavelength of about 450 nm are fixed one by one in a metal lead frame 2b having a plurality of recesses. Has been. Further, the n-side electrode 15 (see FIG. 6) of each LED chip 1 is electrically connected to the lead frame 2b. The p-side translucent electrode 16 (see FIG. 6) of each LED chip 1 is electrically connected to one end of a lead (not shown) via a metal wire (not shown). .

  Here, in the LED array 80 according to the sixth embodiment, as shown in FIG. 15, a transparent portion 9 made of a transparent silicon resin is formed to cover the LED chip 1 so as to completely embed each recess of the lead frame 2 a. Has been. Then, sheet-like phosphor layers 81, 82, and 83 made of silicon resin are formed in this order so as to cover the upper end surface of the lead frame 2b and the flat upper surface of the transmission portion 9. The phosphor layers 81, 82, and 83 are examples of the “wavelength conversion unit” in the present invention. The phosphor layers 81, 82, and 83 are mixed with a phosphor that develops a yellow color.

  In the sixth embodiment, a thin-film light diffusion portion 84 made of Al having a thickness of several nm is formed between the phosphor layer 81 and the phosphor layer 82, and the phosphor layer 82 and the phosphor A thin-film light diffusing portion 85 made of Al having a thickness of several nm is formed between the layer 83. Further, the thickness (several nm) of the light diffusion portions 84 and 85 is formed sufficiently smaller than the thickness of the phosphor layers 81, 82 and 83. FIG. 15 shows a state in which light diffusion portions 84 and 85 are formed by expressing Al particles in a plurality of circular shapes.

  The remaining structure and manufacturing process of the LED array 80 according to the sixth embodiment are the same as those of the second embodiment. The effects of the sixth embodiment are also the same as those of the second embodiment.

(Modification of the sixth embodiment)
FIG. 16 is a cross-sectional view showing a detailed structure of an LED array according to a modification of the sixth embodiment of the present invention. Referring to FIG. 16, in the LED array 90 according to the modification of the sixth embodiment, unlike the sixth embodiment, two layers of light diffusion portions 91 and 92 sandwiched between the phosphor layers 81 to 83 include case formed by a continuous film made of titanium oxide (TiO ₂₎ will be described.

Here, in the modification of the sixth embodiment, as shown in FIG. 16, a film-like light diffusion portion 91 made of TiO ₂ having a thickness of about 6 nm is provided between the phosphor layer 81 and the phosphor layer 82. At the same time, a film-like light diffusion portion 92 made of TiO ₂ having a thickness of about 6 nm is formed between the phosphor layer 82 and the phosphor layer 83. The light diffusion portions 91 and 92 having a film thickness of about 6 nm are formed in a continuous film state by a vacuum evaporation method. Each of the light diffusion portions 91 and 92 is an example of the “light diffusion layer” in the present invention. The other structure and manufacturing process of the LED array 90 according to the modification of the sixth embodiment are the same as those of the sixth embodiment.

  In the modification of the sixth embodiment, as described above, the light diffusion formed between the respective layers of the phosphor layers 81 to 83 so as to cover the surfaces of the phosphor layers 81 to 83 in a continuous film state. By arranging the portions 91 and 92, the light transmitted from the respective LED chips 1 through the phosphor layer 81 is all incident on the light diffusion portion 91 formed in a continuous film state. Further, the light transmitted through the light diffusion portion 91 and the phosphor layer 82 is all incident on the light diffusion portion 92 formed in a continuous film state. Thereby, the light which injects into the light-diffusion parts 91 and 92 can be diffused more reliably.

Further, in the modification of the sixth embodiment, the light diffusion portions 91 and 92 are taken out of the light diffusion portions 91 and 92 by using a continuous film made of TiO ₂ having a light transmittance higher than that of Al. The light intensity to be increased can be increased. Moreover, since the light diffusion portions 91 and 92 are continuous films, the directivity such as the color tone of the emitted light can be reduced. Incidentally, when the light diffusing portion 91 and 92 of the TiO _2, the light emitted from the light diffusion part 91 and 92 is believed to be spread primarily by refraction. The remaining effects of the modification of the sixth embodiment are similar to those of the aforementioned sixth embodiment.

(Seventh embodiment)
FIG. 17 is a cross-sectional view illustrating a detailed structure of the LED array according to the seventh embodiment of the present invention. 17, in the LED array 100 according to the seventh embodiment, unlike the sixth embodiment, the light diffusion portion 103 sandwiched between the phosphor layers 101 and 102 includes Nb ₂ O ₅ particles 104. The case where it forms with a sheet-like silicon resin film is demonstrated.

Here, in the seventh embodiment, as shown in FIG. 17, Nb ₂ O ₅ particles 104 are dispersed in silicon resin between the phosphor layer 101 and the phosphor layer 102 to form a film (sheet shape). A continuously formed light diffusion portion 103 is formed. The film-like (sheet-like) light diffusing portion 103 has a thickness of several hundred μm. Therefore, the Nb ₂ O ₅ particles 104 are also dispersed in the film thickness direction (B2 direction). Each of the phosphor layers 101 and 102 is an example of the “wavelength converter” in the present invention. The phosphor layers 101 and 102 are mixed with a phosphor that develops yellow color. The light diffusing unit 103 is an example of the “light diffusing layer” in the present invention.

  The remaining structure and manufacturing process of the LED array 100 according to the seventh embodiment are the same as those of the sixth embodiment.

In the seventh embodiment, as described above, a sheet-like light continuously formed in a film shape with the Nb ₂ O ₅ particles 104 dispersed in the thickness direction (B2 direction) of the film in the light diffusion portion 103. By using the diffusion layer, the Nb ₂ O ₅ particles 104 in which the light transmitted from the LED chip 1 through the phosphor layer 101 and incident on the light diffusion portion 103 is dispersed not only in the planar dispersion but also in the thickness direction of the film. Therefore, the function of the light diffusing unit 103 can be used more effectively. Thereby, incident light can be more reliably diffused. The remaining effects of the seventh embodiment are similar to those of the aforementioned sixth embodiment.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

  For example, in the first to seventh embodiments, an example in which one or two light diffusing parts are formed between the two or three phosphor layers (wavelength converting part) is shown. The invention is not limited to this, and a light diffusing portion may be formed between each of a plurality of phosphor layers (wavelength converting portions) other than two or three layers.

  In the second and fifth embodiments, the example in which the transmissive portion 9 made of silicon resin is formed so as to completely fill the concave portion of the lead frame 2 has been described. However, the present invention is not limited thereto, and the transmissive portion is not limited thereto. The portion 9 may be in a vacuum state or air may be enclosed.

  In the manufacturing process of the second embodiment, the example in which the phosphor layer 31, the light diffusion portion 33, and the phosphor layer 32 are sequentially laminated on the upper surface of the transmission portion 9 has been described. However, the present invention is not limited to this. First, when mass productivity is taken into consideration, the Al thin film light diffusion portion 33 is formed in advance on the sheet-like phosphor layer 31 using a vacuum deposition method, and the sheet-like phosphor layer is formed on the light diffusion portion 33. 32 are bonded together to form a phosphor sheet integrally. And you may make it form the LED lamp 30 by bonding this fluorescent substance sheet on the upper surface of the transmission part 9. FIG. In addition, in the modified example of the second embodiment and the manufacturing processes in the third to seventh embodiments, a phosphor sheet is formed by applying the same manufacturing process as the manufacturing process shown in the present modified example, and the LED A lamp (LED array) can be formed.

  Moreover, in the said 3rd Embodiment, the average particle diameter of the light-diffusion part 51 arrange | positioned at the side near the LED chip 1 is smaller than the average particle diameter of the light-diffusion part 52 arrange | positioned at the side far from the LED chip 1. Although the present invention is not limited to this, the ratio of the total plane area of the Al island portion to the total plane area of the light diffusion portion arranged on the side close to the LED chip You may form a light-diffusion part so that it may become smaller than the ratio for which the total plane area of the part of Al island with respect to the total plane area of the light-diffusion part on the side far from an LED chip accounts.

  Moreover, in the said 4th Embodiment, the average particle diameter of the light-diffusion part 61 arrange | positioned at the side near the LED chip 1 is larger than the average particle diameter of the light-diffusion part 62 arrange | positioned at the side far from the LED chip 1. Although the present invention is not limited to this, the ratio of the total plane area of the Al island portion to the total plane area of the light diffusion portion arranged on the side close to the LED chip You may form a light-diffusion part so that it may become larger than the ratio for which the total plane area of the part of Al island with respect to the total plane area of the light-diffusion part on the side far from an LED chip accounts.

  In the fifth embodiment, an example in which a phosphor layer 71 that emits blue light and a phosphor layer 72 that develops red and yellow are stacked in this order on the emission direction side of the LED chip 75 that emits ultraviolet light. However, the present invention is not limited to this, and when the phosphor layer is multilayered, a phosphor layer (wavelength) mixed with a phosphor emitting light having a relatively short wavelength on the side closer to the LED chip (semiconductor light emitting element). It is preferable to arrange and laminate a phosphor layer in which a phosphor that emits light having a relatively long wavelength is mixed on the side far from the LED chip. According to this modification, light emitted at a short wavelength from the phosphor layer on the side close to the LED chip efficiently excites the phosphor emitting at a long wavelength when passing through the outer phosphor layer. Therefore, the excitation efficiency of the phosphor can be further improved.

  In the modification of the fifth embodiment, the phosphor layer 71 that develops blue color and the phosphor layer 72 that produces red and yellow colors are stacked in this order on the emission direction side of the LED chip 75 that emits ultraviolet light. However, the present invention is not limited to this, and on a LED chip that emits blue light, a phosphor layer that emits green light (wavelength conversion unit) and a phosphor layer that develops red and yellow colors (wavelength conversion) Part) may be laminated in this order.

  Moreover, in the said 2nd-7th embodiment, although the example which provided the sheet-like fluorescent substance layer (wavelength conversion part) on the flat upper surface of the transmission part 9 was shown, this invention is not limited to this, Similarly to the first embodiment, the LED lamp may be formed by a method of injecting a phosphor layer made of silicon resin into the recess of the lead frame 2.

  Further, in the sixth embodiment and the modification thereof, the example in which the two light diffusion portions are formed between the layers of the three phosphor layers (wavelength conversion portions) has been described, but the present invention is not limited thereto. Instead, as in the seventh embodiment, an LED array may be formed by forming a single light diffusion portion between two phosphor layers (wavelength conversion portions).

  Moreover, in the said 1st-7th embodiment, although the example which formed the fluorescent substance layer using silicon resin was shown, this invention is not restricted to this, Resin which does not produce degradation in the use temperature range of a semiconductor light-emitting device If so, other resins than the silicon resin may be used. In addition, although the refractive index of the resin member is generally about 1.4 to about 1.6, the resin having a light refractive index or a lower refractive index depending on the use environment or purpose of the semiconductor light emitting device. A member may be used.

  In the first to fifth embodiments, the example in which the metal thin film made of Al is used for the island-like or net-like light diffusing portion is shown. However, the present invention is not limited to this, and the emitted light from the LED chip is used. A thin metal film made of, for example, Ag, which is a material that can be appropriately reflected and refracted may be used for the light diffusion portion.

In the modification of the sixth embodiment and the seventh embodiment, a dielectric film made of TiO _{2 in the} light diffusion portion and a dielectric made of Nb ₂ O ₅ as the light diffusion material are dispersed in the silicon resin. Although an example using each of the sheet-like continuous films has been shown, the present invention is not limited to this. May be formed.

  In the above embodiment, an example in which a semiconductor light emitting element is formed using a nitride compound semiconductor has been described. However, the present invention is not limited thereto, and the semiconductor light emitting element is formed using ZnO (zinc oxide) or the like. May be.

It is sectional drawing which showed the structure of the LED lamp by 1st Embodiment of this invention. It is a figure for demonstrating the structure of the LED lamp by 1st Embodiment shown in FIG. It is a figure for demonstrating the structure of the LED lamp by 1st Embodiment shown in FIG. It is a figure for demonstrating the structure of the LED lamp by 1st Embodiment shown in FIG. It is a figure for demonstrating the structure of the LED lamp by 1st Embodiment shown in FIG. It is a figure for demonstrating the structure of the LED lamp by 1st Embodiment shown in FIG. It is a figure for demonstrating the manufacturing process of the LED lamp by 1st Embodiment shown in FIG. It is a figure for demonstrating the manufacturing process of the LED lamp by 1st Embodiment shown in FIG. It is sectional drawing which showed the detailed structure of the light emission part of the LED lamp by the modification of 1st Embodiment of this invention. It is sectional drawing which showed the detailed structure of the LED lamp by 2nd Embodiment of this invention. It is sectional drawing which showed the detailed structure of the light emission part of the LED lamp by the modification of 2nd Embodiment of this invention. It is sectional drawing which showed the detailed structure of the light emission part of the LED lamp by 3rd Embodiment of this invention. It is sectional drawing which showed the detailed structure of the light emission part of the LED lamp by 4th Embodiment of this invention. It is sectional drawing which showed the detailed structure of the LED lamp by 5th Embodiment of this invention. It is sectional drawing which showed the detailed structure of the LED array by 6th Embodiment of this invention. It is sectional drawing which showed the detailed structure of the LED array by the modification of 6th Embodiment of this invention. It is sectional drawing which showed the detailed structure of the LED array by 7th Embodiment of this invention.

Explanation of symbols

1,75 LED chip (semiconductor light emitting device)
5, 6 Phosphor layer (wavelength converter)
7 Light diffusion part 21, 22, 23 Phosphor layer (wavelength conversion part)
24, 25 Light diffusion part 31, 32 Phosphor layer (wavelength conversion part)
33 Light diffusion part 41, 42, 43 Phosphor layer (wavelength conversion part)
44, 45 Light diffuser 51, 52 Light diffuser 61, 62 Light diffuser 71, 72 Phosphor layer (wavelength converter)
73 Light diffusion part 81, 82, 83 Phosphor layer (wavelength conversion part)
84, 85 Light diffusion part 91, 92 Light diffusion part (light diffusion layer)
101, 102 Phosphor layer (wavelength converter)
103 Light diffusion part (light diffusion layer)

Claims (5)

A semiconductor light emitting device;
A wavelength conversion unit including a phosphor that is provided on at least two layers on the light emitting direction side of the semiconductor light emitting element and converts the wavelength of the light emitted from the semiconductor light emitting element;
And a light diffusing unit arranged to be sandwiched between the wavelength conversion units.   The light diffusing part is a state in which the light diffusing part made of metal is distributed in an island shape in plan view, or adjacent light diffusing parts are partially coupled at the outer edge of the light diffusing part. The semiconductor light-emitting device according to claim 1, further comprising a thin-film light diffusing portion formed in a net shape.   The semiconductor light emitting device according to claim 1, wherein the light diffusion portion is provided in two or more layers. The light diffusing portion includes a thin-film light diffusing portion made of a metal formed in an island-like state in plan view,
The light diffusing part disposed on the side close to the semiconductor light emitting element and the light diffusing part disposed on the side far from the semiconductor light emitting element have an average particle diameter or a total plane area of the light diffusing part. The semiconductor light-emitting device according to claim 3, wherein at least one of the proportions of the planar area of the island-like portions is different.   The semiconductor light emitting device according to claim 1, wherein the light diffusing unit includes a light diffusing layer formed so as to cover a surface of the wavelength converting unit in a continuous film state.

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