JP2014067965A - Light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device capable of obtaining high-luminance light emission with a uniform light distribution and less luminance unevenness or the like.SOLUTION: The light-emitting device comprises: a base which is made of an inorganic insulating material and has a mounting surface for a light-emitting element; an element connection terminal formed on the mounting surface; a light-emitting element mounted on the mounting surface and electrically connected to the element connection terminal; a resin sealing layer provided on the mounting surface so as to cover the outside of the light-emitting element; and a light diffusion plate which is provided in contact with the resin sealing layer so as to cover an emission light extraction part and is made of a sintered compact of a glass ceramic composition containing a glass powder and a ceramic powder. In the glass ceramic composition, the content of the ceramic powder is preferably 10-20 mass% with respect to the total content of the ceramic powder and the glass powder.

Description

  The present invention relates to a light-emitting device, and more particularly to a light-emitting device that emits high-intensity light with uniform spread and little unevenness.

  In recent years, light emitting devices equipped with LED elements are used not only for general illumination but also as small and medium-sized liquid crystal backlights and in-vehicle headlights as the brightness and whitening of light emitting diode (LED) elements progress. It has been proposed.

  In order to suppress the increase in the price of the light emitting device and increase the amount of light flux, a multichip type light emitting device in which a plurality of small and inexpensive LED elements (chips) are arranged and mounted in one package has been proposed. Such a light emitting device has the following problems. That is, the LED element is close to a point light source, and the directivity of light is an advantage. However, in the multi-chip type light emitting device, the spread of light emission (light distribution) is uneven, and unevenness such as luminance and color tone is caused. There was a problem that it was likely to occur. For this reason, it has been difficult to use a multi-chip type light emitting device for applications that require light with high uniformity of light distribution, such as in-vehicle headlights and projectors.

  Resin-made light in which ceramic powder is dispersed in order to improve the uniformity of light distribution in a light-emitting device equipped with LED elements and eliminate unevenness such as brightness and color tone (hereinafter sometimes referred to as brightness unevenness). A structure in which a diffusion plate is installed as an external cover is known. However, the resin constituting the light diffusing plate is deteriorated by the radiated light or heat from the LED element, and the transmittance of the light diffusing plate is greatly reduced. Therefore, the service life is short, and high luminance light is obtained over a long period of time. I couldn't.

  In addition, a light emitting device including a light diffusing plate made of dense polycrystalline ceramic such as translucent alumina, aluminum nitride, and aluminum oxynitride has been proposed (for example, see Patent Document 1). However, in the light-emitting device described in Patent Document 1, since the transmittance of the light diffusing plate is too high and the diffusibility is insufficient, nonuniform orientation and uneven brightness cannot be improved.

JP 2007-258228 A

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a light-emitting device capable of obtaining high-luminance light emission with uniform light distribution and less luminance unevenness.

  The light-emitting device of the present invention includes a base having a mounting surface made of an inorganic insulating material and including a mounting portion on which the light-emitting element is mounted, an element connection terminal formed on the mounting surface of the base, and the mounting portion of the base A light emitting device mounted on the device and electrically connected to the device connection terminal, a resin sealing layer provided on a mounting surface of the base so as to cover an outside of the light emitting device, and light emission from the light emitting device And a light diffusion plate made of a sintered body of a glass ceramic composition containing glass powder and ceramic powder, which is provided in contact with the resin sealing layer so as to cover the take-out portion.

In the light emitting device of the present invention, the content of the ceramic powder in the glass ceramic composition is preferably 10 to 20% by mass with respect to the total content of the ceramic powder and the glass powder. The light diffusing plate preferably has a thickness of 200 to 300 μm. Furthermore, the visible light transmittance of the light diffusing plate is preferably 75 to 90%. Then, the ceramic powder is alumina powder is preferable, the glass powder, as represented by mol% based on oxides, the _{SiO 2 57~65%, B 2 O} 3 and 13 to 18%, the _Al 2 _{O 3} 3 It is preferable to have a glass composition containing 0.5 to 6% in total of at least one selected from ˜8%, CaO 9 to 23%, Na ₂ O and K ₂ O.

  According to the light emitting device of the present invention, it is possible to obtain light with high luminance (luminous intensity) with uniform light distribution, which is spread of light emission, little luminance unevenness and the like. In particular, even in a multi-chip type light-emitting device equipped with a plurality of small and relatively inexpensive light-emitting elements, it is possible to obtain high-intensity light with good light distribution characteristics and little unevenness in luminance. There is a great contribution to the reduction of power consumption and expansion of applications.

1 shows an embodiment of a light-emitting device of the present invention, FIG. 1A is a plan view seen from the upper surface side, and FIG. 1B is a cross-sectional view of the light-emitting device of FIG. FIG.

  Hereinafter, although an embodiment of the present invention is described, the present invention is not limited to this.

  A light-emitting device according to an embodiment of the present invention is made of an inorganic insulating material and has a substrate having a light-emitting element mounting surface, an element connection terminal formed on the substrate mounting surface, and a substrate mounting portion. A light emitting element connected to the connection terminal, a resin sealing layer provided on the mounting surface of the substrate so as to cover the outside of the light emitting element, and a light extraction portion from the light emitting element are disposed to cover the light emitting element. A light diffusing plate. The light diffusion plate is composed of a sintered body of a glass ceramic composition, and is disposed in contact with the resin sealing layer.

The light diffusing plate is composed of a sintered body of a glass ceramic composition containing glass powder and ceramic powder.
The glass powder contained in the glass ceramic composition, in mol% based on oxides, _{SiO 2 57~65%, B 2 O} 3 and 13 to 18%, the _Al 2 _{O 3} 3 to 8%, CaO and 9-23%, those having a glass composition containing 0.5 to 6% in total of at least one selected from Na ₂ O and _{K 2} O is preferable. By using the glass powder having such a composition, a light diffusion plate having a sufficiently high light transmittance and good light diffusibility can be obtained.

  The components of the glass powder will be described below. In the description of the glass component, “%” represents the mol% expression in terms of oxide unless otherwise specified.

SiO ₂ is a glass network former. When the content of SiO ₂ is less than 57%, it is difficult to obtain a stable glass and the chemical durability may be lowered. On the other hand, when the content of SiO ₂ exceeds 65%, the glass melting temperature (Ts) and the glass transition temperature (Tg) may be excessively increased. The content of SiO ₂ is preferably 58% or more, more preferably 59% or more, and particularly preferably 60% or more. Further, the content of SiO ₂ is preferably 64% or less, more preferably 63% or less.

B ₂ O ₃ is a glass network former. When the content of B ₂ O ₃ is less than 13%, Ts and Tg may be excessively high. On the other hand, when the content of B ₂ O ₃ exceeds 18%, it is difficult to obtain a stable glass and the chemical durability may be lowered. The content of B ₂ O ₃ is preferably 14% or more, more preferably 15% or more. Further, the content of B ₂ O ₃ is preferably 17% or less, more preferably 16% or less.

Al ₂ O ₃ is added to increase the stability, chemical durability and strength of the glass. If the content of Al ₂ O ₃ is less than 3%, the glass may become unstable. On the other hand, when the content of Al ₂ O ₃ exceeds 8%, Ts and Tg may be excessively high. The content of Al ₂ O ₃ is preferably 4% or more, more preferably 5% or more. Further, the content of Al ₂ O ₃ is preferably 7% or less, more preferably 6% or less.

  CaO is added to increase the stability of the glass and the crystal precipitation, and to decrease Ts and Tg. If the CaO content is less than 9%, Ts may be excessively high. On the other hand, if the CaO content exceeds 23%, the glass may become unstable. The content of CaO is preferably 12% or more, more preferably 13% or more, and particularly preferably 14% or more. Further, the content of CaO is preferably 22% or less, more preferably 21% or less, and particularly preferably 20% or less.

Na ₂ O and K ₂ O are added to lower Tg. When the total content of Na ₂ O and K ₂ O is less than 0.5%, Ts and Tg may be excessively high. On the other hand, when the total content of Na ₂ O and K ₂ O exceeds 6%, chemical durability, particularly acid resistance may be lowered, and electrical insulation may be lowered. The total content of Na ₂ O and K ₂ O is preferably 0.8% or more and 5% or less.

  In addition, the composition of the glass powder for light diffusing plates is not necessarily limited to what consists only of the said component, Other components can be contained in the range with which various characteristics, such as Tg, are satisfy | filled. In this embodiment, lead oxide is not contained. When other components are contained, the total content is preferably 10% or less.

  Such a glass powder for a light diffusing plate is obtained by producing glass having the above composition by a melting method and pulverizing it by a dry pulverization method or a wet pulverization method. In the case of the wet pulverization method, it is preferable to use water or ethyl alcohol as a solvent. Examples of the pulverizer include a roll mill, a ball mill, and a jet mill.

The 50% particle size (D ₅₀ ) of the glass powder for the light diffusion plate is preferably 0.5 μm or more and 4 μm or less. In this specification, D ₅₀ is a value measured using a laser diffraction / scattering particle size distribution measuring apparatus. If D ₅₀ of the glass powder is less than 0.5μm is not only the glass powder becomes difficult to handle easily agglomerated, fear is the time required for pulverization it is too long. On the other hand, there is a possibility that D ₅₀ of the glass powder is more than 4 [mu] m, increase and insufficient sintering of Ts occurs. The particle size is adjusted by, for example, classification as necessary after pulverization. The maximum particle size of the light diffusion plate glass powder is preferably 20 μm or less. When the maximum particle size exceeds 20 μm, the sinterability of the glass powder is lowered, and there is a possibility that undissolved components remain in the sintered body. The maximum particle size of the glass powder for light diffusion plate is more preferably 10 μm or less.

Examples of the ceramic powder blended into the glass ceramic composition for the light diffusion plate together with such a glass powder include alumina powder, zirconia powder, silica powder, titania powder, and composite powders thereof. From the viewpoint of powder availability and economical viewpoint, it is preferable to use alumina powder. D ₅₀ of the ceramic powder for the light diffusion plate is preferably 0.3 to 5.0 μm.

  The content of the ceramic powder in the glass ceramic composition for the light diffusing plate is preferably 10 to 20% by mass with respect to the total content of the ceramic powder and the glass powder. When the content ratio of the ceramic powder is less than 10% by mass, the diffusibility (spreading of light) and the uniformity of light diffusion of the light diffusing plate are insufficient, and unevenness in luminance and color tone of the light emitting device is eliminated. It is difficult. Moreover, when the content rate of ceramic powder exceeds 20 mass%, the light transmittance of a light diffusing plate will become inadequate and a high-intensity light-emitting device will not be obtained.

  The light diffusing plate can be manufactured by firing a green sheet for a light diffusing plate. A green sheet for a light diffusion plate is prepared by adding a slurry prepared by adding a binder, a plasticizer, a dispersant, a solvent, etc. to a mixture obtained by mixing the glass powder and the ceramic powder in the above-described ratio, by a doctor blade method or the like. After being formed into a sheet and dried, it is obtained by cutting and processing into a predetermined shape (for example, a circular shape that is the shape of the opening of the frame).

  As the binder, polyvinyl butyral, acrylic resin or the like can be suitably used. As the plasticizer, dibutyl phthalate, dioctyl phthalate, butyl benzyl phthalate, or the like can be used. As the solvent, organic solvents such as toluene, xylene, 2-propanol and 2-butanol can be suitably used.

  The green sheet for a light diffusing plate thus obtained is degreased with a binder or the like, if necessary, and then fired for sintering the glass ceramic composition to obtain a light diffusing plate.

  Degreasing is performed, for example, under the condition of holding at a temperature of 500 ° C. to 600 ° C. for 1 hour to 10 hours. When the degreasing temperature is less than 500 ° C. or the degreasing time is less than 1 hour, the binder or the like may not be sufficiently removed. On the other hand, if the degreasing temperature is about 600 ° C. and the degreasing time is about 10 hours, the binder and the like can be sufficiently removed, and if it exceeds this, productivity and the like may be lowered.

  Moreover, baking can adjust time suitably in the temperature range of 800 to 930 degreeC in consideration of acquisition of the precise | minute structure of a light diffusing plate, and productivity. Specifically, it is preferable to hold at a temperature of 850 ° C. or more and 900 ° C. or less for 20 minutes or more and 60 minutes or less, and a temperature of 860 ° C. or more and 880 ° C. or less is particularly preferable. If the firing temperature is less than 800 ° C., the light diffusion plate may not be obtained as a dense structure. On the other hand, when the firing temperature exceeds 930 ° C., productivity and the like may be lowered due to deformation of the light diffusion plate.

  The thickness of the light diffusion plate thus produced is preferably in the range of 200 to 300 μm. When the thickness of the light diffusing plate is less than 200 μm, the light diffusibility (light spread) and the uniformity of light diffusion become insufficient, and it is difficult to eliminate unevenness in luminance and color tone of the light emitting device. If the thickness of the light diffusing plate exceeds 300 μm, the light transmittance becomes insufficient, and a high-luminance light emitting device cannot be obtained. The light transmittance of the light diffusing plate is preferably 75 to 90% on the average of the entire light in the wavelength region of visible light.

  Further, such a light diffusion plate can contain a phosphor. In order to obtain a light diffusing plate containing a phosphor, a predetermined amount of phosphor powder is blended together with glass powder and ceramic powder in the production of a green sheet for a light diffusing plate to produce a green sheet containing the phosphor. And the light-diffusion plate containing fluorescent substance can be obtained by baking this green sheet. As the phosphor to be contained in the light diffusion plate, a phosphor having the same or different emission color as that of the phosphor to be contained in the resin sealing layer can be used. For example, both the resin sealing layer and the light diffusing plate can contain a yellow phosphor to increase the luminous efficiency of white light. Moreover, the color tone (color temperature) of white light can be changed by including a yellow phosphor in the resin sealing layer and a red or orange phosphor in the light diffusion plate.

  In the light emitting device according to the embodiment of the present invention, a light diffusion plate made of a sintered body of a glass ceramic composition including glass powder and ceramic powder is disposed so as to cover a light extraction portion from the light emitting element. Therefore, light with uniform light spread (light distribution) and less luminance unevenness and color unevenness can be obtained. In particular, even in a multi-chip type light-emitting device using a plurality of relatively inexpensive small-sized LED chips as light-emitting elements, good light emission with uniform spread of light emission and less luminance unevenness can be obtained.

  Moreover, since the light diffusing plate used in the present invention is composed of a sintered body of a glass ceramic composition containing glass powder and ceramic powder, deterioration due to radiant light and radiant heat from the LED element does not occur. Further, by adjusting the content ratio of the ceramic powder, it is easy to adjust the balance between light transmittance and light diffusibility (orientation uniformity) for the light diffusing plate.

Furthermore, since the light diffusion plate is disposed in contact with the resin sealing layer and has a structure in which no gap (air layer) is interposed between the resin sealing layer and the light diffusion plate, high light extraction efficiency is achieved. Can be obtained.
That is, for example, in a conventional structure in which a resin cover such as polycarbonate (refractive index 1.6) is provided on a sealing layer made of a resin having a refractive index of 1.55, the resin sealing layer and the resin cover Since there is an air layer with a refractive index of 1.0 between them, the light emitted from the light emitting element and transmitted through the resin sealing layer passes through the interface between the resin sealing layer and the air layer, the air layer, before going out. 3 passes through the layer interface having different refractive indexes, such as the interface between the resin cover and the resin cover and the interface between the resin cover and the external air layer. Therefore, the amount of light that travels straight due to the refraction of light at these interfaces is reduced, and the light extraction efficiency is greatly reduced.

  On the other hand, in the light emitting device of the present invention, for example, the light diffusion plate (for example, refractive index 1.55) is directly disposed on the sealing layer made of resin having a refractive index of 1.55. The light radiated from the light emitting element and transmitted through the resin sealing layer has two interfaces, the interface between the resin sealing layer and the light diffusion plate, the interface between the light diffusion plate and the external air layer, and the like. Since it only passes through the interface and the refractive index of the resin sealing layer and the light diffusion plate is substantially the same, the light reflection at the interface between the resin sealing layer and the light diffusion plate is extremely small. Therefore, in the light emitting device of the present invention, a decrease in light extraction efficiency due to the arrangement of the light diffusion plate is suppressed, and high light extraction efficiency can be obtained.

  Hereinafter, an embodiment of a light emitting device of the present invention will be described with reference to the drawings. Although this embodiment shows an example of a light emitting device in which six 2-wire type light emitting elements are electrically connected in parallel and mounted, the present invention is not limited to this.

  FIG. 1A is a plan view of an embodiment of the light emitting device of the present invention as viewed from the upper surface (mounting surface) side, and FIG. 1B shows the light emitting device of FIG. It is sectional drawing cut | disconnected by the line. FIG. 1A shows a state in which the resin sealing layer and the light diffusion plate are removed.

  A light-emitting device 10 of the present invention is mounted on a light-emitting element mounting substrate 1 and a light-emitting element mounting substrate 1, and a pair of electrodes are each bonded in parallel to a predetermined wiring conductor layer and connected in parallel. The six light emitting elements (for example, LED elements) 11 are provided.

  The light emitting element mounting substrate 1 has a substrate body 2 having a substantially square planar shape and a substantially flat plate shape. In this specification, “substantially” indicates a visual level. The substrate body 2 is made of an inorganic insulating material, and a frame 3 is formed on an upper surface (mounting surface) 21. A cavity having a circular planar shape is formed by the frame body 3, and the bottom surface of the cavity is a mounting area on which the light emitting element 11 is mounted.

  Examples of the inorganic insulating material constituting the substrate body 2 include an aluminum oxide sintered body (alumina ceramic), an aluminum nitride sintered body, a mullite sintered body, and a glass ceramic composition containing glass powder and ceramic powder. Examples thereof include a sintered body (low temperature co-fired ceramics, hereinafter referred to as LTCC). From the viewpoints of high reflectivity, ease of production, easy processability, economy, etc., LTCC is preferred in the present invention.

  In the embodiment of the present invention, the substrate body 2 has a substantially square planar shape and a substantially flat plate shape, but the shape, thickness, size, etc. of the substrate body 2 are not particularly limited, and the light emission to be mounted The number and arrangement pattern of the elements 11 can be changed according to the design of the light emitting device 10. Moreover, the raw material composition of LTCC which comprises the substrate main body 2, sintering conditions, etc. are demonstrated in the manufacturing method of the light-emitting device 10 mentioned later. The substrate body 2 preferably has a bending strength of, for example, 250 MPa or more from the viewpoint of suppressing damage or the like when the light-emitting element 11 is mounted or after use.

  A wiring conductor layer 4 that is electrically connected to the light emitting element 11 is provided in the mounting region of the substrate body 2. The wiring conductor layer 4 includes an anode-side or cathode-side electrode (first electrode) 41 disposed in the center of the mounting region, and a first electrode disposed in the periphery of the mounting region. And a plurality of electrodes (second electrodes) 42 on the opposite pole side. Three electrodes as the second electrodes 42 are arranged at substantially equal intervals on the circumference surrounding each first electrode 41.

  In the embodiment, the number of the second electrodes 42 is three, which is 1/2 of the number of the light emitting elements 11 to be mounted, but this is the minimum necessary number, and other necessary electrodes, etc. Can be formed as needed. That is, the planar shape and arrangement position of the first electrode 41 constituting the wiring conductor layer 4 and the planar shape and number of the second electrodes 42 are not limited to those illustrated. Moreover, the constituent material of the wiring conductor layer 4 will not be restrict | limited especially if it is the same as that of the wiring conductor layer 4 used for the board | substrate 1 for normal light emitting element mounting. The thickness of the wiring conductor layer 4 is preferably 5 to 15 μm.

  A conductor layer 4a for reflection and heat dissipation is formed in the mounting region of the substrate body 2, and an overcoat layer 5 made of a glass material for protecting the conductor layer 4a is formed thereon. . As a material constituting the conductor layer 4a, the same material as that of the wiring conductor layer 4 can be used. The conductor layer 4a for reflection and heat dissipation is preferably formed so as to cover almost the entire mounting area at a slight distance from the end of the wiring conductor layer 4. The overcoat layer 5 is provided so as to cover the conductor layer 4a for reflection and heat dissipation, but the ease of layer formation and the rise of the end of the overcoat layer 5 adversely affect the flatness of the surface. In consideration of the above, it is preferable to form the wiring conductor layer 4 at a slight distance from the end of the wiring conductor layer 4. The six mounting portions T on which the six light emitting elements 11 are mounted are respectively arranged at substantially equal intervals in an annular region between the first electrode 41 and the second electrode 42 group. .

The glass material constituting the overcoat layer 5 is preferably one containing at least SiO ₂ , B ₂ O ₃ , and borosilicate glass containing at least one selected from Na ₂ O and K ₂ O as a constituent component. Moreover, this glass material can contain ceramic powder in the ratio of 10 mass% or less. The content of the ceramic powder is preferably 3% by mass or more. By containing ceramic powder, the strength of the overcoat layer 5 may be increased. Moreover, the heat dissipation of the overcoat layer 5 may be improved. Furthermore, from the viewpoint of chemical resistance such as acid resistance, the glass material preferably contains silica powder or alumina powder as ceramic powder.

  The overcoat layer 5 is formed by firing a composition obtained by mixing a glass powder such as the borosilicate glass and, if necessary, the ceramic powder. For example, the overcoat layer 5 includes a glass powder and a ceramic powder. The mixed powder is formed into a paste, screen-printed, and fired. The thickness of the overcoat layer 5 is preferably in the range of 5 to 20 μm. The formation of the conductor layer 4a for reflection and heat dissipation and the overcoat layer 5 is not essential, and may be omitted depending on the constituent material of the substrate body 2.

  The other surface of the substrate body 2 is a non-mounting surface 22 on which the light emitting element 11 is not mounted, and a pair of external electrode terminals 6 (anode side and cathode side) are provided on this non-mounting surface. These external electrode terminals 6 are connected to the first electrode 41 and the second electrode provided on the mounting surface of the substrate body 2 through connection vias 7 and an internal wiring layer 43 formed inside the substrate body 2, respectively. The electrode 42 is electrically connected.

  The external electrode terminal 6, the connection via 7 and the internal wiring layer 43 can be used without particular limitation as long as they are the same as those used for the light emitting element mounting substrate 1 in general. Further, regarding the arrangement of the external electrode terminal 6, the connection via 7, and the internal wiring layer 43, six light emitting elements mounted thereon via the wiring conductor layer 4 (the first electrode 41 and the second electrode 42). It is sufficient that the elements 11 are arranged so as to be electrically connected in parallel.

  Further, in order to reduce the thermal resistance of the substrate body 2, a thermal via and a heat dissipation layer (not shown) can be embedded in the substrate body 2.

  In the light-emitting device 10 of the present invention, all of the six light-emitting elements 11 are light-emitting elements having the same bottom surface, and are disposed on the six mounting portions T of the light-emitting element mounting substrate 1, respectively, and are silicone die bonds that are adhesives. It is fixed to the mounting portion T using a material (not shown).

  One of the electrodes of each light emitting element 11 is connected to the first electrode 41 located in the center of the mounting region of the light emitting element mounting substrate 1 by the bonding wire 12, and the other electrode has three first electrodes. The bonding electrode 12 is connected to the nearest electrode of the two electrode 42 groups. Thus, the twelve bonding wires 12 connecting the six to twelve electrodes of the six light emitting elements 11 are arranged so as not to cross each other. Note that the arrangement of the light emitting elements 11 is not limited to the arrangement shown in FIG.

  And in the light-emitting device 10 of this invention, the resin sealing layer 13 which consists of mold resin is provided so that these light-emitting elements 11 and the bonding wire 12 may be covered, and glass powder and ceramic powder as mentioned above on it. A substantially flat light diffusing plate 14 composed of a sintered body of a glass ceramic composition containing For example, the light diffusing plate 14 is fitted into a recess 3 a provided in the upper part of the frame 3, and the lower surface is disposed so as to be in contact with the upper surface of the resin sealing layer 13 without a gap.

  In the light emitting device 10 of the embodiment of the present invention, the light diffusion plate 14 made of a sintered body of a glass ceramic composition containing glass powder and ceramic powder is disposed on the resin sealing layer 13. The spread (light distribution) of the light emitted from the six light emitting elements 11 and radiated to the outside through the resin sealing layer 13 becomes uniform. Accordingly, it is possible to obtain light with high luminance (luminance) with little luminance unevenness and color unevenness. In addition, since the light diffusion plate 14 is disposed in contact with the resin sealing layer 13 and the air layer is not interposed between the resin sealing layer 13 and the light diffusion plate 14, the light extraction efficiency is improved. high. The light emitting device 10 according to the embodiment can be used for applications that require light with high uniformity of light distribution, such as in-vehicle headlights and projectors.

  The embodiment of the light emitting device 10 according to the present invention has been described above with an example, but the light emitting device according to the present invention is not limited thereto. As long as it does not contradict the spirit of the present invention, the configuration can be changed as necessary.

  In order to manufacture the light emitting device 10 of the present invention, the light emitting device mounting substrate 1 is manufactured by applying materials and manufacturing methods normally used for the LTCC substrate, and then the light emitting device mounting substrate 1 is used to manufacture the light emitting device. Can be manufactured.

  Hereinafter, the method for manufacturing the light emitting device of the present invention will be described by taking the method for manufacturing the light emitting device 10 shown in FIG. 1 as an example.

  The light emitting device 10 shown in FIG. 1 can be manufactured by a manufacturing method including the following steps (A) to (H). In the following description, the members used for the manufacture will be described with the same reference numerals as those of the finished product.

(A) Green sheet production process for main body Using a glass ceramic composition containing glass powder and ceramic powder, a green sheet (green sheet for main body) for forming the substrate main body 2 of the light emitting element mounting substrate 1 is prepared. Make it. The main body green sheet includes an upper layer green sheet for forming an upper layer, an inner layer green sheet for forming an inner layer, and a lower layer green sheet for forming a lower layer. In this step, a green sheet (green sheet for frame) for forming the frame 3 is also produced.

  The green sheet for the main body is prepared by adding a binder and, if necessary, a plasticizer, a dispersant, a solvent, etc. to a glass ceramic composition containing glass powder and ceramic powder, and preparing a slurry by a doctor blade method or the like. It can be manufactured by molding into a sheet and drying. Moreover, the green sheet for a frame is obtained by processing the green sheet thus produced into a predetermined shape.

  The glass powder for main body for producing the green sheet for main body preferably has a Tg of 550 ° C. or higher and 700 ° C. or lower. When Tg is less than 550 ° C., degreasing may be difficult, and when it exceeds 700 ° C., the shrinkage start temperature becomes high and the dimensional accuracy may be lowered.

  The glass powder is preferably one in which crystals precipitate when fired at 800 ° C. or higher and 930 ° C. or lower. In the case where crystals do not precipitate, there is a possibility that sufficient mechanical strength cannot be obtained. Furthermore, the thing whose crystallization peak temperature (Tc) measured by DTA (differential thermal analysis) is 880 degrees C or less is preferable. When Tc exceeds 880 ° C., the dimensional accuracy may be reduced.

As such a glass powder for a main body, it is 57 to 65% of SiO ₂ , 13 to 18% of B ₂ O ₃ , 9 to 23% of CaO, and 3 of Al ₂ O ₃ in terms of mol% based on oxide. 8%, those containing from 0.5 to 6% of at least one of them in total selected from _{K 2} O and Na ₂ O are preferred. By using the glass powder having such a composition, it becomes easy to improve the surface flatness of the substrate body 2.

Here, SiO ₂ serves as a glass network former. When the content of SiO ₂ is less than 57%, it is difficult to obtain a stable glass and the chemical durability may be lowered. On the other hand, when the content of SiO ₂ exceeds 65%, Ts and Tg may be excessively high. The content of SiO ₂ is preferably 58% or more, more preferably 59% or more, and particularly preferably 60% or more. Further, the content of SiO ₂ is preferably 64% or less, more preferably 63% or less.

B ₂ O ₃ is a glass network former. When the content of B ₂ O ₃ is less than 13%, Ts and Tg may be excessively high. On the other hand, when the content of B ₂ O ₃ exceeds 18%, it is difficult to obtain a stable glass, and the chemical durability may be lowered. The content of B ₂ O ₃ is preferably 14% or more, more preferably 15% or more. Further, the content of B ₂ O ₃ is preferably 17% or less, more preferably 16% or less.

Al ₂ O ₃ is added to increase the stability, chemical durability, and strength of the glass. If the content of Al ₂ O ₃ is less than 3%, the glass may become unstable. On the other hand, when the content of Al ₂ O ₃ exceeds 8%, Ts and Tg may be excessively high. The content of Al ₂ O ₃ is preferably 4% or more, more preferably 5% or more. Further, the content of Al ₂ O ₃ is preferably 7% or less, more preferably 6% or less.

  CaO is added to increase the stability of the glass and the crystal precipitation, and to decrease Ts and Tg. If the CaO content is less than 9%, Ts may be excessively high. On the other hand, when the content of CaO exceeds 23%, the glass may become unstable. The content of CaO is preferably 12% or more, more preferably 13% or more, and particularly preferably 14% or more. Further, the content of CaO is preferably 22% or less, more preferably 21% or less, and particularly preferably 20% or less.

K ₂ O and Na ₂ O are added to lower Tg. When the total content of K ₂ O and Na ₂ O is less than 0.5%, Ts and Tg may be excessively high. On the other hand, when the total content of K ₂ O and Na ₂ O exceeds 6%, chemical durability, particularly acid resistance may be lowered, and electrical insulation may be lowered. The total content of K ₂ O and Na ₂ O is preferably 0.8% or more and 5% or less.

  In addition, the glass powder for main bodies is not necessarily limited to what consists only of the said component, but can contain another component in the range with which various characteristics, such as Tg, are satisfy | filled. When other components are contained, the total content is preferably 10% or less.

  The glass powder for main body is obtained by producing glass having the above composition by a melting method and pulverizing it by a dry pulverization method or a wet pulverization method. In the case of the wet pulverization method, it is preferable to use water or ethyl alcohol as a solvent. Examples of the pulverizer include a roll mill, a ball mill, and a jet mill.

D ₅₀ of the glass powder for main body is preferably 0.5 μm or more and 2 μm or less. If D ₅₀ of the glass powder is less than 0.5 [mu] m, handling the glass powder is likely to agglomerate are not only difficult, uniform dispersion becomes difficult. On the other hand, if the D ₅₀ of the glass powder exceeds 2μm, there is a possibility that increase and insufficient sintering of the glass softening temperature is generated. For example, the particle size may be adjusted by classification as necessary after pulverization.

  As the ceramic powder, those conventionally used for manufacturing LTCC substrates can be used. For example, alumina powder, zirconia powder, or a mixture of alumina powder and zirconia powder can be suitably used. In particular, together with alumina powder, ceramic powder having a higher refractive index than alumina (hereinafter referred to as high refractive index ceramic powder) can be used.

The high refractive index ceramic powder is a component for improving the reflectance of the sintered body (substrate), and examples thereof include titania powder, zirconia powder, and stabilized zirconia powder. While the refractive index of alumina is about 1.8, the refractive index of titania is about 2.7 and the refractive index of zirconia is about 2.2, which is higher than that of alumina. . The D ₅₀ of the ceramic powder including these high refractive index ceramic powders is preferably 0.5 μm or more and 4 μm or less.

  In such a glass powder and ceramic powder, for example, the glass powder is 30% by mass to 50% by mass and the ceramic powder is 50% by mass to 70% by mass, and the mixture is mixed with a binder, A slurry can be obtained by adding a plasticizer, a dispersant, a solvent, or the like as necessary.

  As the binder, for example, polyvinyl butyral, acrylic resin and the like can be suitably used. As the plasticizer, for example, dibutyl phthalate, dioctyl phthalate, butyl benzyl phthalate and the like can be used. As the solvent, organic solvents such as toluene, xylene, 2-propanol and 2-butanol can be suitably used.

  The slurry thus obtained is formed into a sheet shape by a doctor blade method or the like and dried to produce, for example, three main body green sheets (upper layer green sheet, inner layer green sheet and lower layer green sheet). In addition, a green sheet for a frame is manufactured by processing the green sheet manufactured in the same manner into a predetermined shape.

(B) Conductive paste layer forming step A through-hole for a connection via is formed at a predetermined position of each main body green sheet (upper layer green sheet, inner layer green sheet, and lower layer green sheet). Further, the conductor paste layer 4 for the wiring conductor, the conductor paste layer 43 for the internal wiring layer, and the conductor paste layer 6 for the external electrode terminal are formed at predetermined positions on the upper layer green sheet, the inner layer green sheet and the lower layer green sheet, respectively. To do. Further, a conductive paste layer 7 for connection via is formed by filling the through hole formed in each green sheet for main body with a conductive paste. Further, a reflective and heat dissipating conductor paste layer 4a is formed in a predetermined region of the upper layer green sheet.

  The conductor paste layer 4 for wiring conductors, the conductor paste layer 43 for internal wiring layers, the conductor paste layer 7 for connection vias, the conductor paste layer 6 for external electrode terminals, and the conductor paste layer 4a for reflection and heat dissipation are formed as conductors. The method of apply | coating or filling a paste by screen printing is mentioned. The film thickness of these conductive paste layers to be formed is such that the first and second electrodes 41 and 42, the internal wiring layer 43, the connection via 7, the external electrode terminal 6, the reflection and heat dissipation conductor layer 4a finally obtained. The film thickness is adjusted to a predetermined film thickness.

  As the conductive paste, for example, a paste obtained by adding a vehicle such as ethyl cellulose to a metal powder mainly composed of copper, silver, gold or the like, and a solvent or the like as required can be used. In addition, as said metal powder, the metal powder which consists of silver powder and silver, platinum, or palladium is used preferably.

(C) Overcoat glass paste layer forming step In the upper layer green sheet, on the reflective and heat radiating conductor paste layer 4a formed in the step (B), the mounting area except for the vicinity of the conductor paste layer 4 for the wiring conductor The overcoat glass paste layer 5 is formed by screen printing so as to cover almost the entire area of the film.

  The overcoat glass paste is a paste prepared by adding a vehicle such as ethyl cellulose to a composition obtained by mixing the glass powder for the overcoat layer and the ceramic powder as necessary, and a solvent as necessary. Can be used. The film thickness of the overcoat glass paste layer 5 to be formed is adjusted so that the finally obtained overcoat layer 5 has a thickness of 5 to 20 μm.

(D) Laminating step Green sheet with conductor paste layer obtained by forming conductor paste layer (further overcoat glass paste layer in upper layer green sheet) on green sheet for main body, conductor paste layer and overcoat glass paste A green sheet with a layer and a green sheet for a frame are superposed in a predetermined order and integrated by thermocompression to obtain an unsintered substrate.

(E) Firing step The unfired substrate obtained in the step (D) is defatted with a binder or the like, if necessary, and then fired to sinter the glass ceramic composition and the like, thereby mounting the light emitting element mounting substrate 1. And

  Degreasing is performed, for example, under the condition of holding at a temperature of 500 ° C. to 600 ° C. for 1 hour to 10 hours. When the degreasing temperature is less than 500 ° C. or the degreasing time is less than 1 hour, the binder or the like may not be sufficiently removed. On the other hand, if the degreasing temperature is about 600 ° C. and the degreasing time is about 10 hours, the binder and the like can be sufficiently removed, and if it exceeds this, productivity and the like may be lowered.

  In addition, in the firing, the time can be appropriately adjusted in a temperature range of 800 ° C. to 930 ° C. in consideration of obtaining a dense structure of the base body 2 and productivity. Specifically, it is preferable to hold at a temperature of 850 ° C. or more and 900 ° C. or less for 20 minutes or more and 60 minutes or less, and a temperature of 860 ° C. or more and 880 ° C. or less is particularly preferable. If the firing temperature is less than 800 ° C., the base body 2 may not be obtained as a dense structure. On the other hand, if the firing temperature exceeds 930 ° C., the productivity may be lowered due to deformation of the base body 2. Further, when a metal paste containing a metal powder containing silver as a main component is used as the conductor paste, if the firing temperature exceeds 880 ° C., there is a risk that the predetermined shape cannot be maintained due to excessive softening. .

  Thus, the light-emitting element mounting substrate 1 is obtained. After firing, the surface of the wiring conductor layer 4 (first and second electrodes 41, 42) exposed on the mounting surface is coated as necessary. It is also possible to dispose a conductive protective film, such as Ni / gold plating, used for conductor protection in the light emitting element mounting substrate 1.

(F) Light-Emitting Element Mounting Step Six light-emitting elements 11 such as LED chips each having a pair of electrodes on the upper surface are arranged on the six mounting portions of the light-emitting element substrate 1 obtained in the step (E). Then, after fixing using a silicone die bond material as an adhesive, one of the electrodes of each light emitting element 11 is placed on the first electrode 41 located in the center of the mounting region of the light emitting element mounting substrate 1 and the other electrode. Are connected to the nearest second electrode 42 by a bonding wire 12.

(G) Sealing Resin Injection / Filling Step A sealing transparent resin such as silicone resin is injected / filled into the cavity of the light emitting element mounting substrate 1 on which the light emitting element 11 is mounted in the step (F). . The sealing transparent resin can contain a phosphor so that white light can be obtained by color mixing with light emitted from the light emitting element 11.

(H) Installation Step of Light Diffusing Plate The light diffusing plate 14 manufactured by the above-described method or the like is disposed on the sealing resin injection / filling layer formed in the step (G). Then, the sealing resin is cured by heating, and at the same time, the light diffusion plate 14 is adhered and fixed to the upper surface of the cured resin layer (resin sealing layer 13).

  Although the manufacturing method of the light emitting device 10 has been described above, the frame green sheet need not be a single green sheet, and may be a laminate of a plurality of green sheets. Further, the number of main body green sheets excluding the frame green sheet is not necessarily three, and may be two or four or more. Furthermore, the order of forming each part in the manufacture of the light emitting element mounting substrate 1 can be changed as appropriate.

  Next, specific examples of the present invention will be described. The present invention is not limited to these examples.

Examples 1-9
The light emitting device shown in FIG. 1 was manufactured by the following method. Examples 1 to 8 are examples of the present invention, and Example 9 is a comparative example.

<Manufacture of light-emitting element mounting substrate>
First, main body green sheets (upper layer green sheet, inner layer green sheet, and lower layer green sheet) for manufacturing the substrate body 2 of the light emitting element mounting substrate 1 were prepared. In the production of the green sheet for the main body, in terms of mol% based on oxide, SiO ₂ is 60.4%, B ₂ O ₃ is 15.6%, Al ₂ O ₃ is 6%, CaO is 15%, K _The raw materials were blended and mixed so that ₂ O was 1% and Na ₂ O was 2%. The raw material mixture was put in a platinum crucible and melted at 1600 ° C. for 60 minutes, and then the molten glass was poured out and cooled. did. This glass was pulverized for 40 hours by an alumina ball mill to produce a glass powder for a substrate body. In addition, ethyl alcohol was used as a solvent for pulverization.

  Next, 38% by mass of this glass powder, 38% by mass of alumina powder (manufactured by Showa Denko KK, trade name: AL-45H), zirconia powder (manufactured by Daiichi Rare Element Chemical Industry, trade name: HSY-3F-J) ) Is mixed so as to be 24% by mass and mixed, and then 50 g of this mixture is mixed with an organic solvent (toluene, xylene, 2-propanol, 2-butanol mixed at a mass ratio of 4; 2; 2; 1). 15 g, 2.5 g of plasticizer (di-2-ethylhexyl phthalate), 5 g of polyvinyl butyral as a binder (trade name; PVK # 3000K, manufactured by Denka), and further a dispersant (trade name: BYK180) 0 0.5 g was mixed and mixed to prepare a slurry.

  This slurry was applied onto a PET film by a doctor blade method, and the dried green sheet was laminated so that the thickness after firing was 0.25 mm for each of the upper layer and the lower layer, A green sheet was produced. In addition, a green sheet for a frame was manufactured by processing a green sheet manufactured in the same manner as the green sheet for a main body into a predetermined shape.

  On the other hand, conductive metal powder (manufactured by Daiken Chemical Industry Co., Ltd., trade name: S550) and ethyl cellulose as a vehicle are blended at a mass ratio of 85:15, and α as a solvent so that the solid content is 85 mass%. After dispersing in terpineol, the mixture was kneaded in a porcelain mortar for 1 hour, and further dispersed three times with a three roll to produce a conductor paste.

  A through hole having a diameter of 0.15 mm is formed in a portion corresponding to the connection via of one of the green sheets for the substrate body (upper layer green sheet) using a hole puncher, and the conductor is formed by screen printing. The paste was filled to form a connection via conductor paste layer 7. Thereafter, the conductor paste layers 41 and 42 for the first electrode and the second electrode were formed on the upper surface of the green sheet by screen printing the conductor paste. Also, the conductor paste layer 4a for reflection and heat dissipation was formed by screen printing the conductor paste in a predetermined region on the upper surface of the upper layer green sheet.

  Further, through holes each having a diameter of 0.15 mm are formed in a portion corresponding to the connection via of the green sheet for the lower layer using a hole puncher, and the conductive paste is filled by the screen printing method to form a conductive paste layer for the connection via 7 was formed. Moreover, the conductor paste layer 43 for internal wiring layers was formed on the upper surface of the lower layer green sheet by screen printing.

  Furthermore, the conductor paste layer 6 for external electrode terminals was formed by printing the said conductor paste on the lower surface of the green sheet for lower layers.

  Next, a glass paste for the overcoat layer is prepared by adding a vehicle such as ethyl cellulose, a solvent, etc. to a composition obtained by mixing the powder of borosilicate glass for the overcoat layer and the ceramic powder. Prepared. Then, in the upper layer green sheet, the overcoat glass paste layer is formed by screen printing on the reflective and heat radiating conductor paste layer 4a so as to cover almost the entire mounting area except for the vicinity of the conductor paste layer 4 for the wiring conductor. 5 was formed.

  Next, the green sheet for the upper layer with the conductor paste layer and the overcoat glass paste layer thus prepared and the green sheet for the lower layer with the conductor paste layer are sequentially stacked, and the green for the frame is further placed on the upper layer green sheet. After the sheets were stacked, they were integrated by thermocompression bonding. Thus, an unfired substrate was obtained. The obtained non-fired substrate was degreased by holding at 550 ° C. for 5 hours, and further fired by holding at 870 ° C. for 30 minutes to produce a light-emitting element mounting substrate 1.

<Manufacture of light diffusion plate>
In Examples 1 to 8, first, a green sheet for a light diffusing plate for producing a light diffusing plate was produced. In the production of a green sheet for a light diffusing plate, SiO ₂ is 60.4%, B ₂ O ₃ is 16.6%, Al ₂ O ₃ is 6%, and CaO is 13% in terms of oxide-based mol%. The raw materials were mixed and mixed so that K ₂ O was 2% and Na ₂ O was 2%, and this raw material mixture was put in a platinum crucible and melted at 1500 to 1600 ° C. for 60 minutes, and then the molten glass Was poured out and cooled. This glass was pulverized with an alumina ball mill for 40 hours to obtain a glass powder for a light diffusion plate. In addition, ethyl alcohol was used as a solvent for pulverization.

_{D 50} a ([mu] m) of the obtained glass powder B, a laser diffraction / scattering particle size distribution analyzer (manufactured by Shimadzu Corporation, trade name; SALD2100) was measured using a was 2.5 [mu] m.

  Next, this glass powder and alumina powder (manufactured by Showa Denko KK, trade name: AL-45H) were blended at a mass ratio shown in Table 1, mixed, and 50 g of this mixture was mixed with an organic solvent (toluene, xylene, 2 -Propanol, 2-butanol mixed in a mass ratio of 4; 2; 2; 1) 15 g, 2.5 g of plasticizer (di-2-ethylhexyl phthalate), polyvinyl butyral as a binder (trade name, manufactured by Denka) And 5 g of PVK # 3000K) and 0.5 g of a dispersant (manufactured by Big Chemie, trade name: BYK180) were mixed and mixed to prepare a slurry.

  This slurry was applied onto a PET film by the doctor blade method, and the dried green sheet was laminated so that the thickness after firing was as shown in Table 1 (μm), and then cut and processed into a circle. A green sheet for a light diffusion plate was produced.

  Next, the thus produced green sheet for light diffusing plate is degreased by holding at 550 ° C. for 5 hours, and further, kept at 870 ° C. for 30 minutes and fired to obtain the light diffusing plate 14 used in Examples 1-8. Manufactured.

  In Example 9, a 500 μm-thick light diffusion plate (manufactured by NGK, trade name: High Serum) made of translucent alumina was used.

  Subsequently, the transmittance | permeability of the light diffusing plate of Examples 1-9 obtained by the said method was measured as shown below.

<Transmittance of light diffusion plate>
Using a light source (manufactured by Asahi Spectroscopic Co., Ltd., apparatus name: LAX-C100), the light that passed through the light diffusion plate used in Examples 1 to 9 was condensed with an integrating sphere FOIS-1 manufactured by Ocean Optonix. And the average value of the visible light transmittance | permeability was computed with the spectroscope by Asahi Spectroscopy (Asahi Spectroscopy company, apparatus name; HSU-100S).

  Next, six LED elements (manufactured by Epistar, trade name: ES-CEBLV24) 6 die-bonding materials (Shin-Etsu Chemical Co., Ltd.) are mounted on the six mounting portions T of the light-emitting element mounting substrate 1 manufactured as described above. Manufactured and trade name: KER-3000-M2), and then a pair of electrodes of each LED element is respectively bonded to predetermined wiring conductor layers 4 (first electrode 41 and second electrode 42) by bonding wires 12. Electrically connected. Further, a phosphor-containing resin in which a phosphor is contained in a transparent resin for sealing (trade name: CSR-1016A, manufactured by Shin-Etsu Chemical Co., Ltd.) so as to obtain white light is contained in the cavity of the light-emitting element mounting substrate 1 Then, the light diffusion plate 14 was disposed on the injection / filling layer. Then, the injection / filling layer was cured by heating, and the light diffusion plate 14 was adhered to the resin sealing layer 13 which was a cured layer.

  The light-emitting device 10 thus obtained was made to emit light by applying 210 mA using a voltage / current generator (manufactured by Advantest, trade name: R6243). The light distribution characteristic of the light obtained by the light emitting device 10 is changed to a spectroscopic device (Spectra Corp., device name: SOLIDLAMBDA / CCD / LED / MONITOR / PLUS), and an LED photometric measurement stage (Spectra Corp., device name). Measurement was carried out using a device equipped with MAS-L0702.

  The light distribution characteristics are measured from the center of the outer surface of the light diffusing plate 14 which is the light emitting surface of the light emitting device 10, with the vertical direction to the light emitting surface being 0 ° and 0.1 ° to 45 ° left and right. This was done by measuring the light intensity every °. Then, in the obtained light distribution curve, the light intensity at 0 ° and the difference between the highest light intensity and the lowest light intensity (hereinafter referred to as light distribution light intensity difference) were calculated.

  Table 1 shows the measurement results of the 0 ° light intensity and the light distribution light intensity difference. The 0 ° luminous intensity and the light distribution luminous intensity difference were defined as relative luminous intensity (%) when the luminous intensity (cd) at 0 ° when the light diffusion plate was not used was used as a reference (100%). In Examples 1 to 9, the luminous intensity at 0 ° is negative, but the smaller the absolute value, the smaller the decrease in luminous intensity and luminous efficiency due to the installation of the light diffusion plate 14. This value is preferably 10% or less in absolute value. Further, the light distribution luminous intensity difference (%) is preferably 20% or less from the viewpoint of uniformity of light emission spread and reduction in luminance unevenness.

  From Table 1, in the light-emitting device 10 of Examples 1-8 in which the light diffusing plate 14 made of a sintered body of a glass ceramic composition containing glass powder and alumina powder was provided in contact with the resin sealing layer 13, 0 ° It can be seen that the absolute value of the light intensity is sufficiently small and the light distribution light intensity difference (%) is sufficiently small. In particular, in the light emitting devices 10 of Examples 1 to 3 and Examples 6 and 7 having the light diffusion plate 14 having a thickness of 200 to 300 μm with an alumina powder content of 10 to 20 mass%, the luminous intensity of 0 ° The absolute value is 10% or less, and the light distribution luminous intensity difference (%) is 20% or less. The spread is uniform, the luminance unevenness is small, and light emission with high luminous intensity and efficiency is obtained.

  On the other hand, in the light emitting device of Example 9 provided with the light diffusing plate made of translucent alumina, the absolute value of the luminous intensity at 0 ° is small, but the light distribution luminous intensity difference (%) is as large as 30% or more, It can be seen that the uniformity of the spread of light emission is low and luminance unevenness and the like are not sufficiently reduced.

  According to the light emitting device of the present invention, it is possible to obtain light with high brightness with uniform light spread (light distribution), less uneven brightness, and the like. Moreover, high light extraction efficiency can be obtained. Therefore, the light-emitting device of the present invention can be used for applications that require light with high light distribution uniformity, such as in-vehicle headlights and projectors.

DESCRIPTION OF SYMBOLS 1 ... Light emitting element mounting substrate, 2 ... Substrate body, 3 ... Frame, 4 ... Wiring conductor layer, 4a ... Reflection and heat radiation conductor layer, 5 ... Overcoat layer, 6 ... External electrode terminal, 7 ... Connection via, DESCRIPTION OF SYMBOLS 10 ... Light-emitting device, 11 ... Light emitting element, 12 ... Bonding wire, 13 ... Resin sealing layer, 41 ... 1st electrode, 42 ... 2nd electrode, 43 ... Internal wiring layer.

Claims (6)

A substrate made of an inorganic insulating material and having a mounting surface including a mounting portion on which the light emitting element is mounted;
An element connection terminal formed on the mounting surface of the substrate;
A light emitting element mounted on the mounting portion of the base body and electrically connected to the element connection terminal;
A resin sealing layer provided on the mounting surface of the base so as to cover the outside of the light emitting element;
A light diffusing plate comprising a sintered body of a glass ceramic composition containing glass powder and ceramic powder, which is provided in contact with the resin sealing layer so as to cover a light extraction portion from the light emitting element. A light emitting device characterized.   2. The light emitting device according to claim 1, wherein in the glass ceramic composition, the content of the ceramic powder is 10 to 20 mass% with respect to the total content of the ceramic powder and the glass powder.   The light-emitting device according to claim 1, wherein the light diffusion plate has a thickness of 200 to 300 μm.   The light-emitting device according to claim 1, wherein the light diffusing plate has a visible light transmittance of 75 to 90%.   The light emitting device according to claim 1, wherein the ceramic powder is alumina powder. The glass powder is expressed in mol% based on oxide, SiO ₂ 57-65%, B ₂ O ₃ 13-18%, Al ₂ O ₃ 3-8%, CaO 9-23%, Na ₂ O and _K light emitting device according to claim 1 having a glass composition containing from 0.5 to 6% in total of at least one selected from ₂ O.

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