JP2013254820A - Substrate for mounting light-emitting element and light-emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate for mounting a light-emitting element, which is capable of providing light having excellent color rendering properties and is excellent in productivity.SOLUTION: A substrate 10 for mounting a light-emitting element includes: a substrate body 11 having a mounting surface 12 on which a light-emitting element is to be mounted; and a colored glass layer 22 provided on the mounting surface 12 of the substrate body 11.

Description

  The present invention relates to a light-emitting element mounting substrate and a light-emitting device, and more particularly to a light-emitting element mounting substrate and a light-emitting device using the same.

  In recent years, light emitting devices that emit white light using light emitting diode elements have been used as illumination, various displays, backlights for large liquid crystal TVs, and the like. As such a light emitting device, a device that uses a light emitting diode element that emits blue light and a yellow light emitting phosphor that emits yellow light by blue excitation and obtains white light by mixing blue light and yellow light is known. ing. Further, a blue light emitting diode element that emits ultraviolet light, a blue light emitting phosphor that emits blue light by ultraviolet excitation, a green light emitting phosphor that emits green light, and a red light emitting phosphor that emits red light is used. A device that obtains white light by mixing light, green light, and red light is known. Further, a light emitting diode element that emits blue light, a light emitting diode element that emits green light, and a light emitting diode element that emits red light, and obtains white light by mixing blue light, green light, and red light. Are known.

  A light-emitting device that emits white light, particularly a light-emitting device used for illumination or the like, can emit white light with good color rendering so that the illumination object looks natural, such as white with good red reproducibility. It is required that light can be emitted. For example, a light emitting diode element that emits ultraviolet light, a blue light emitting phosphor that emits blue light by ultraviolet excitation, and a green light emitting phosphor that emits green light are used as light emitting white light with good color rendering. One using a red light-emitting phosphor that emits red light is known (for example, see Patent Document 1).

  In addition, for example, a red light emitting phosphor that emits red light is arranged around a light emitting diode element that emits blue light, and yellow light is emitted so as to cover the light emitting diode element and the red light emitting phosphor. It is known to arrange a yellow-emitting phosphor that performs (see, for example, Patent Document 2). Furthermore, it is known that a coating layer containing a yellow light emitting phosphor that emits yellow light and a ceramic composite for light conversion that emits red light are sequentially arranged on the light emitting surface side of the light emitting diode element that emits blue light. (For example, see Patent Document 3).

JP 2007-5549 A JP 2010-272687 A JP 2006-169422 A

  As described above, in a light emitting device that emits white light, a method for emitting white light with good color rendering properties has been studied. However, the conventional method is likely to have a complicated structure and is not necessarily excellent in productivity. The present invention has been made to solve the above-described problems, and it is an object of the present invention to provide a light-emitting element mounting substrate that can obtain light with good color rendering properties and good productivity, and a light-emitting device using the same. And

  The light emitting element mounting substrate of the present invention includes a substrate body having a mounting surface on which the light emitting element is mounted, and a colored glass layer provided on the mounting surface of the substrate body.

  The light emitting device of the present invention includes the above-described light emitting element mounting substrate of the present invention, a light emitting element mounted on a mounting surface of the light emitting element mounting substrate, and a phosphor provided to cover the light emitting element. And a molding material.

  According to the substrate for mounting a light emitting element of the present invention, by providing a colored glass layer on the mounting surface of the substrate body, when the light emitting element is mounted to form a light emitting device, light with good color rendering can be emitted. Further, according to the light emitting device of the present invention, light having good color rendering can be emitted by using the light emitting element mounting substrate.

The top view on the element mounting side which shows one Embodiment of the light emitting element mounting substrate. The top view of the back surface side of the light emitting element mounting substrate shown in FIG. FIG. 2 is a cross-sectional view taken along line AA of the light emitting element mounting substrate shown in FIG. 1. Sectional drawing which shows one Embodiment of a light-emitting device. Sectional drawing which shows embodiment of the light emitting element mounting substrate which does not have a reflection layer.

Hereinafter, embodiments of a light emitting element mounting substrate and a light emitting device of the present invention will be described.
The light emitting element mounting substrate of the embodiment includes a substrate body having a mounting surface on which the light emitting element is mounted, and a colored glass layer provided on at least a part of the mounting surface of the substrate body. . Further, the light emitting device of the embodiment includes the light emitting element mounting substrate, the light emitting element mounted on the mounting surface of the light emitting element mounting substrate, and a molding material having a phosphor provided so as to cover the light emitting element. It is characterized by having.

  In general, in a light-emitting device, part of light emitted from a light-emitting element or a phosphor is incident on a mounting surface on which the light-emitting element is mounted, reflected, and re-emitted to the light-emitting surface side. According to the light emitting element mounting substrate of the embodiment, when the light emitting element is mounted to emit light by providing the colored glass layer on the mounting surface on which the light emitting element of the substrate body is mounted, the colored glass layer causes the colored glass layer to emit light. More color components similar to the color tone of the layer (color tone) can be reflected than other color components. Therefore, the color tone of the colored glass layer (colored color tone) is adjusted to the same color tone as the color component required for improving the color rendering, specifically, the same color tone required for improving the color reproducibility. By adjusting, it is possible to relatively increase the color components required for improving the color rendering properties and to emit light with improved color rendering properties.

  For example, in the case of a light-emitting device using a light-emitting diode element that emits blue light as a light-emitting element and a yellow light-emitting phosphor that emits yellow light by blue excitation as a phosphor, the red component is not sufficient, so color rendering properties are not necessarily obtained. Cannot be emitted, and in particular, light with good red reproducibility cannot be emitted. In this case, by providing a colored glass layer having a red color, the red component is reflected and increased in comparison with other color components, so that light with good color rendering can be emitted, and particularly the red reproducibility is good. Can emit light.

  Moreover, a colored glass layer can be comprised from glass and a coloring agent, for example, can be formed by baking the composition for glass layers containing the glass powder for glass layers, and a coloring agent. For this reason, when the substrate body is fired at a low temperature like a glass ceramic substrate, it can be formed by firing at the same time as firing the substrate body, and can be easily formed by firing in the case of other ceramic substrates. In particular, conventionally, a reflective layer made of silver or the like is provided on the surface of the substrate body in order to improve luminous efficiency and the like. There is a light emitting element mounting substrate having a structure with an overcoat layer. In such a light emitting element mounting substrate, a colored glass layer may be formed instead of the overcoat layer, greatly increasing the manufacturing apparatus and manufacturing process. Since it is not necessary to change, it can manufacture easily.

  1 and 2 are plan views showing an embodiment of a light-emitting element mounting substrate, FIG. 1 shows a main surface side (element mounting side) on which the light-emitting element is mounted, and FIG. The main surface side (back surface side) which is the opposite side is shown. FIG. 3 is a cross-sectional view taken along line AA of the light emitting element mounting substrate shown in FIG. FIG. 4 is a cross-sectional view showing an embodiment of a light emitting device using the light emitting element mounting substrate. FIG. 5 is a cross-sectional view showing another embodiment of the light-emitting element mounting substrate, and is a cross-sectional view showing an embodiment of the light-emitting element mounting substrate having no reflective layer.

  As shown in FIG. 1, the light-emitting element mounting substrate 10 has one main surface as an element mounting side on which a light-emitting element 31 such as a light-emitting diode element is mounted, and the other main surface as shown in FIG. The back side is used for electrical connection with a circuit. In addition, this light emitting element mounting substrate 10 is one in which, for example, six light emitting elements 31 are mounted between an opening at a central portion of the mounting surface 11 and an opening at an outer peripheral portion thereof.

  For example, as shown in FIG. 3, the light emitting element mounting substrate 10 includes a substantially plate-like substrate body 11 that mainly constitutes the light emitting element mounting substrate 10. The substrate body 11 has a mounting surface 12 on which the light emitting element 31 is mounted on the element mounting side which is one main surface side. The substrate main body 11 has, for example, a three-layer structure, and in order from the back surface side opposite to the element mounting side, the first main body portion 14, the second main body portion 15, and the third main body portion. 16 The third body portion 16 has a frame shape, and the surface of the second body portion 15 exposed inside the frame portion of the third body portion 16 becomes the mounting surface 12 of the substrate body 11. .

  A connection terminal 17 that is electrically connected to the light emitting element 31 is provided in a predetermined pattern between the first main body 14 and the second main body 15. The second main body portion 15 is provided with one opening portion in the center portion, and two in total, one on each of the left and right sides so as to be symmetrical on the outer peripheral side of the opening portion in the center portion. A circular opening is provided. The connection terminal 17 is formed in a pattern that is exposed from these openings, and is electrically connected to the light emitting element 31 at the exposed portion.

  For example, as shown in FIG. 4, the light emitting element 31 is disposed between the opening at the center and each opening on the outer peripheral side, and one electrode (not shown) is exposed to the opening at the center. The other electrode (not shown) is electrically connected to the connection terminal 17 exposed at the outer peripheral opening.

  An external electrode terminal 18 that is electrically connected to an external circuit is provided on the back side of the substrate body 11. The connection terminal 17 and the external electrode terminal 18 are electrically connected by a through conductor provided inside the substrate body 11.

  The substrate body 11 is preferably one that can be formed by simultaneously firing a glass paste that will become the colored glass layer 22 described later, or one that does not deform when applied and baked with the glass paste that becomes the colored glass layer 22. Preferably used. As the inorganic material, alumina ceramics, aluminum nitride ceramics, glass ceramics and the like are preferable because they are excellent in terms of thermal conductivity, heat dissipation, strength, and manufacturing cost. Glass ceramics are preferred because they can be formed by simultaneously firing the glass paste that becomes the glass layer 22. Note that the inorganic material may be a metal material. As the substrate body 11 made of a metal material, a lead frame is preferable.

  For example, it is also effective to provide the mounting surface 12 of the substrate body 11 with a reflective layer 21 for reflecting light from the light emitting element 31 and the phosphor when the light emitting device 30 is formed (FIG. 3). The reflective layer 21 is provided on, for example, almost the entire mounting surface 12, that is, almost the entire surface excluding the opening of the second main body portion 15 and its peripheral portion.

  The reflective layer 21 is made of, for example, silver, a silver palladium alloy, or a silver platinum alloy. The reflective layer 21 is, for example, printed on the substrate body 11 by a method such as screen printing by adding a vehicle such as ethyl cellulose to the metal powder made of the above metal material and adding a solvent or the like as necessary. And can be formed by firing. The metal material constituting the reflective layer 21 is preferably one having a high reflectance, and silver is particularly preferably used.

  The colored glass layer 22 is provided in order to obtain light with good color rendering properties, particularly light with improved color reproducibility when the light emitting device 30 is used, and is provided so as to cover the entire reflective layer 21. That is, the colored glass layer 22 is also basically provided on substantially the entire mounting surface 12, specifically, on almost the entire surface excluding the opening of the second main body portion 15 and its peripheral portion. The colored glass layer 22 also has a function of suppressing gas or liquid intrusion into the reflective layer 21 and preventing oxidation or sulfidation of the reflective layer 21.

  The color tone (colored color tone) of the colored glass layer 22 is not particularly limited as long as it can emit light with good color rendering when the light emitting device 30 is used, and depends on the configuration of the light emitting device 30, that is, depending on the insufficient color component. For example, the color tone can be blue, green, yellow, red, or the like. Among these, a red color tone is particularly preferable. For example, when a light emitting diode 30 that emits blue light is used as the light emitting device 30 and a yellow light emitting phosphor that emits yellow light by blue excitation is used as the phosphor, the red component is not sufficient. It is not always possible to emit light with good color rendering properties, and it is not possible to emit light with particularly good red reproducibility. By setting the color tone of the colored glass layer 22 to red, the red component can be increased, light with good color rendering can be emitted, and light with particularly good red reproducibility can be emitted.

  As the color tone (reflection color tone) of the red colored glass layer 22 described above, x = 0.65 to 0.74, y = 0.20 in the chromaticity defined by the CIE (International Commission on Illumination) XYZ color system. Those within the range of ˜0.27 are preferable, and those within the ranges of x = 0.70 to 0.73 and y = 0.25 to 0.26 are more preferable.

  The red colored glass layer 22 preferably has a reflectance of 580 nm or less at a wavelength of 10% or less and a reflectance of 680 nm or more at a wavelength of 20% or more, and a reflectance of a wavelength of 630 nm or less. Is more preferably 15% or less and the reflectance at a wavelength of 700 nm or more is 25% or more. Note that the reflectance can be measured according to a normal method for measuring a reflection spectrum.

  The colored glass layer 22 is provided so that the ratio of the area of the colored glass layer 22 to the area of the mounting surface 12 of the substrate body 11 (area of the colored glass layer 22 / area of the mounting surface 12) is 0.5 or more. Is preferred. Here, when the frame-shaped third main body portion 16 as shown in FIG. 1 is provided, the area of the mounting surface 12 is the second main body exposed inside the frame-shaped portion of the third main body portion 16. The area of the surface of the portion 15 excluding the opening is taken as the area. By providing the ratio of the area to be 0.5 or more, the color rendering property of the emitted light can be effectively improved. The ratio of the area is more preferably 0.6 or more, further preferably 0.7 or more, and particularly preferably 0.8 or more.

  The thickness of the colored glass layer 22 is preferably 10 μm or more. By setting the thickness of the colored glass layer 22 to 10 μm or more, the color rendering properties of the emitted light can be effectively improved. The thickness of the colored glass layer 22 is more preferably 15 μm or more, and further preferably 17 μm or more. Moreover, since productivity etc. will fall when the colored glass layer 22 is too thick, 30 micrometers or less are preferable, 25 micrometers or less are more preferable, and 23 micrometers or less are further more preferable.

  Further, the thermal conductivity of the colored glass layer 22 is preferably 0.5 W / (m · K) or more. When the thermal conductivity of the colored glass layer 22 is less than 0.5 W / (m · K), the heat of the light emitting element 31 is not sufficiently dissipated and sufficient light emission luminance cannot be obtained.

The colored glass layer 22 is composed of, for example, glass and a colorant.
Examples of the glass constituting the colored glass layer 22 include borosilicate glasses such as SiO ₂ —B ₂ O ₃ glass and SiO ₂ —B ₂ O ₃ —RO glass (RO is alkaline earth metal oxide). It is a thing.) Even when the glass is fired at the same time as the reflective layer 21, particularly the silver reflective layer, it is preferable to obtain a dense sintered body without deforming the reflective layer 21.

The glass that constitutes the colored glass layer _22, in addition to SiO _2, B 2 _{O 3} and _RO, can contain components _{Al 2 O 3, R 2 O} ( alkali metal oxides), lead oxide-containing Preferably not. Moreover, the glass which comprises the colored glass layer 22 is not limited to what has the said composition, It can also be set as composition glass different from this.

Examples of other composition glass constituting the colored glass layer 22 include SiO ₂ —B ₂ O ₃ —Al ₂ O ₃ glass, SiO ₂ —B ₂ O ₃ —R ₂ O glass, SiO ₂ —B ₂ O. Examples include _3- Bi ₂ O ₃ glass and SiO ₂ —TiO ₂ —R ₂ O glass.

  The softening point (Ts) of the composition glass described above is preferably 900 ° C. or lower. When the glass softening point (Ts) exceeds 900 ° C., the firing temperature needs to be 900 ° C. or higher in order to obtain a dense sintered body by firing. However, when the reflective layer 21 is a silver reflective layer, the reflective layer 21 may be deformed if fired at the same time. By using a glass having a softening point (Ts) of 900 ° C. or lower, deformation of the reflective layer 21 can be suppressed, and the reflective layer 21 and the colored glass layer 22 can be fired simultaneously.

The colorant is not particularly limited as long as it can effectively color the colored glass layer 22 and can form the colored glass layer 22 by firing, but an inorganic pigment is preferable because the colored glass layer 22 can be formed by firing. Examples of the inorganic pigment include metal oxides, particularly transition metal oxides. For example, oxides such as Co, Ni, Fe, Mn, Sn, and Zr, specifically, Co ₂ O ₃ , NiO, and Fe _2. Examples include O ₃ , MnO, SnO ₂ , ZrO _{2 and the} like.

In the case of Co ₂ O ₃ , a blue color tone is obtained, in the case of NiO, an ocher color tone is obtained, in the case of Fe ₂ O ₃ , a red to reddish brown color tone is obtained, and in the case of MoO ₃ , a milky white color tone is obtained. In the case of SnO ₂ , a pink color tone is obtained, and in the case of ZrO ₂ , a white color tone is obtained. And the colored glass layer 22 of various color tones is obtained by combining these colorants. Further, as the colorant, in addition to the above, for example, a colloidal metal such as Ag or Au may be used.

As a colorant, Fe oxide having a red color is preferable, and Fe ₂ O ₃ is particularly preferable. Fe ₂ O ₃ is also a main coloring component of the petal (Bengara), is easily available industrially, and can emit light with good color rendering when used as the light emitting device 30. In particular, when the light emitting device 30 is a light emitting diode element that emits blue light as the light emitting element 31 and a yellow light emitting phosphor that emits yellow light by blue excitation is used as the phosphor, the red component is not sufficient. Although it is not always possible to emit light with good color rendering, by using Fe ₂ O ₃ as a colorant, the color of the colored glass layer 22 can be changed from red to reddish brown, and light with good color rendering can be emitted.

  The ratio of the colorant in the colored glass layer 22, that is, the ratio of the colorant in the glass and the colorant varies depending on the type of the colorant, but is preferably 1% by mass or more. By setting the ratio of the colorant to 1% by mass or more, the colored glass layer 22 can be effectively colored, and when the light emitting device 30 is formed, light with good color rendering properties can be emitted. The proportion of the colorant is preferably 2% by mass or more, and more preferably 3% by mass or more. Moreover, since there exists a possibility that formation of the colored glass layer 22 by baking may become difficult when the ratio of a coloring agent increases too much, 10 mass% or less is preferable, 8 mass% or less is more preferable, and 5 mass% or less is preferable. Particularly preferred. When a plurality of colorants are used in combination, it is preferable that the total ratio of the colorants falls within the above range.

In particular, the content ratio of the Fe oxide in the colored glass layer 22 is preferably 1 to 10% by mass in terms of Fe ₂ O ₃ . By doing in this way, the colored glass layer 22 can be effectively colored, light having good color rendering properties can be emitted when the light emitting device 30 is formed, and the colored glass layer 22 can be easily formed by firing.

The colorant preferably has a 50% particle size (D ₅₀ ) of 2 to 20 μm. When the colorant has a 50% particle size of 2 μm or more, the dispersibility is good and uniform coloring is obtained. When the colorant has a 50% particle size of 20 μm or less, local coloring is suppressed and uniform coloring is obtained. The 50% particle size of the colorant is more preferably 5 μm or more, and further preferably 8 μm or more. Further, the 50% particle diameter of the colorant is more preferably 15 μm or less, and further preferably 13 μm or more. In the present specification, the 50% particle size is measured using a laser diffraction / scattering particle size distribution measuring apparatus.

  The colored glass layer 22 can contain a ceramic filler in order to diffuse light incident on the colored glass layer 22 from the light emitting element 31 or the like. As the ceramic filler, known ceramic fillers can be used without particular limitation, and for example, alumina powder, zirconia powder, titania powder, or a mixture thereof can be suitably used.

The 50% particle size (D ₅₀ ) of the ceramic filler is preferably λ / 10 to 10λ, for example, where the wavelength of light emitted from the light emitting element 31 is λ. If it is less than λ / 10, the proportion of most of the incident light that is not reflected by the ceramic filler and transmitted through the colored glass layer increases and cannot be sufficiently dispersed. On the other hand, if it exceeds 10λ, the rate at which the light reaching the ceramic filler is reflected and scattered at the interface between the ceramic filler and the glass decreases, and the incident light cannot be sufficiently dispersed.

  The colored glass layer 22 can be formed by firing a glass layer composition that is a mixture containing a glass layer glass powder and a colorant. The colored glass layer 22 may be formed by firing simultaneously with the firing of the substrate body 11, or may be formed by firing after the substrate body 11 is manufactured by firing or the like, and the formation time is particularly limited. Not.

  The glass powder for glass layer can be obtained by producing glass having the above glass 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 as a solvent. The pulverization can be performed using, for example, a pulverizer such as a roll mill, a ball mill, or a jet mill.

The 50% particle size (D ₅₀ ) of the glass layer glass powder is preferably 0.5 to 4 μm. When the 50% particle size of the glass layer glass powder is less than 0.5 μm, the glass layer glass powder is likely to aggregate, making it difficult to handle, and the time required for pulverization may be too long. On the other hand, when the 50% particle size of the glass layer glass powder exceeds 4 μm, the glass softening temperature may increase or the sintering may be insufficient. The particle size can be adjusted, for example, by classification as needed after pulverization.

  The maximum particle size of the glass layer glass powder is preferably 20 μm or less. When the maximum particle diameter exceeds 20 μm, the sinterability of the glass powder for the glass layer is lowered, and undissolved components remain in the sintered body, which may reduce the reflectivity of the colored glass layer 22. The maximum particle size of the glass layer glass powder is more preferably 10 μm or less.

  A composition for colored glass can be prepared by blending and mixing such glass layer glass powder and a colorant, and blending and mixing a ceramic filler as necessary. A colored glass layer 22 can be formed by adding a binder to the colored glass composition to prepare a glass paste, applying the glass paste, and baking it.

  The colored glass layer 22 is formed, for example, by applying a glass paste to the mounting surface 12 of the unfired substrate body 11 and firing the glass paste simultaneously with firing of the unfired substrate body 11 (FIG. 5). Note that an unfired reflective layer 21 may be formed on the mounting surface 12 of the unfired substrate body 11. In this case, a glass paste is applied so as to cover the unfired reflective layer 21, and unfired. The glass paste is fired and formed simultaneously with the firing of the substrate body 11 and the reflective layer 21 (FIG. 3).

  The colored glass layer 22 is not necessarily formed by being fired simultaneously with the firing of the substrate body 11 and the reflective layer 21. For example, the substrate body 11 is other than glass ceramics, specifically, alumina ceramics, aluminum nitride ceramics, or the like. When the substrate body 11 is made of a ceramic obtained by firing at a high temperature, a glass paste may be applied to the mounting surface 12 of the substrate body 11 and fired to form the colored glass layer 22. Further, when the substrate body 11 is a lead frame or the like, a glass paste may be applied to the mounting surface 12 such as the lead frame that is the substrate body 11 and fired to form the colored glass layer 22.

  As shown in FIG. 4, the light emitting device 30 has a light emitting element 31 mounted on a light emitting element mounting substrate 10. For example, a total of six light emitting elements 31 are arranged between the central opening and the outer peripheral opening of the mounting surface 11, and each is fixed to the colored glass layer 22 using an adhesive. A pair of electrodes (not shown) of the light emitting element 31 are electrically connected to the connection terminal 17 by bonding wires 32, respectively. Examples of the light emitting element 31 include a light emitting diode element having an emission peak wavelength in the range of 360 to 470 nm, and particularly an InGaN-based light emitting diode element having an emission peak wavelength in the range of 430 to 470 nm.

  On the mounting surface 11, a molding material 33 is provided so as to cover the light emitting element 31 and the bonding wire 32. As the molding material 33, for example, a silicone resin or an epoxy resin is used. Among these, a silicone resin is preferably used because of excellent light resistance and heat resistance. By dispersing the phosphor in the molding material 33, the light obtained as the light emitting device 30 can be appropriately adjusted to a desired emission color. The phosphor is not necessarily dispersed in the molding material 33. For example, a phosphor layer may be provided on the molding material 33.

  By using the light emitting element 31 and the phosphor together, the phosphor is excited by the light emitted from the light emitting element 31 to emit visible light, and the light emitted from the light emitting element 31 and the visible light emitted from the phosphor are emitted. A desired emission color can be obtained by mixing with light. Moreover, a desired luminescent color can also be obtained by mixing the visible lights radiated | emitted from fluorescent substance. The type of the phosphor is not particularly limited, and can be appropriately selected according to the type of light emitted from the light emitting element and the target emission color.

  According to the light emitting device 30, the colored glass layer 22 is provided by the colored glass layer 22 when the light emitting element 31 emits light because the mounting surface 12 on which the light emitting element 31 of the substrate body 11 is mounted has the colored glass layer 22. The color component similar to the color tone (color tone) can be reflected more than the other color components. Therefore, the color tone of the colored glass layer (colored color tone) is adjusted to the same color tone as the color component required for improving the color rendering, specifically, the same color tone required for improving the color reproducibility. By adjusting, the color components required for improving the color rendering properties can be increased, and light with improved color rendering properties can be emitted.

As the light emitting device 30, for example, a light emitting diode element that emits blue light having an emission peak wavelength within a range of 430 to 470 nm is used as the light emitting element 31, and yellow is obtained by blue excitation as a phosphor to be mixed and dispersed in the molding material 33. One that emits white light using a yellow light-emitting phosphor that emits light is exemplified. In this case, the colored glass layer 22 contains an Fe oxide such as Fe ₂ O _{3 and} preferably has a red color tone. By setting it as the colored glass layer 22 of such a color tone, a red component can be increased and color rendering can be made favorable, and especially the reproducibility of red can be made favorable.

  The average color rendering index Ra of the light emitting device 30 is preferably 80 or more, more preferably 85 or more, and particularly preferably 90 or more. Further, the special color rendering index R9 of the light emitting device 30 is preferably 70 or more, and more preferably 75 or more. The average color rendering index Ra and the special color rendering index R9 are measured according to JIS Z 8726 (Method for evaluating color rendering properties of light sources).

  The light emitting device 30 can be suitably used as, for example, a backlight for a mobile phone or a large liquid crystal display, an illumination for automobiles or decoration, and other light sources. In particular, since the light emitting device 30 is excellent in color rendering, it can be suitably used as illumination for display applications such as products.

Next, a method for manufacturing the light emitting element mounting substrate 10 will be described.
Below, the case where the board | substrate body 11 consists of glass ceramics is demonstrated.

  First, a green sheet is formed. For example, the green sheet is prepared by adding a binder, and if necessary, a plasticizer, a solvent, etc. to a glass ceramic composition containing a glass powder for a substrate body and a ceramic filler, and preparing a slurry by using a doctor blade method or the like. It is formed into a shape and dried. As the green sheet, for example, three green sheets to be the first main body part 14, the second main body part 15, and the third main body part 16 are manufactured.

  The glass powder for substrate main body is not necessarily limited, but a glass transition point (Tg) of 550 to 700 ° C. is preferable. When the glass transition point (Tg) is less than 550 ° C., degreasing described later may be difficult. On the other hand, when the glass transition point (Tg) exceeds 700 ° C., the shrinkage start temperature becomes high and the dimensional accuracy may be lowered.

The glass powder for such a substrate body, for _{example, SiO 2, B 2 O 3} , CaO, Al 2 O 3, K which contains at least one preferably selected from ₂ O and the group consisting of Na ₂ O.

The glass powder for a substrate body can be obtained by producing glass having the above glass 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 as a solvent. The pulverization can be performed using a pulverizer such as a roll mill, a ball mill, or a jet mill.

  In addition, the glass powder for substrate bodies 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 a glass transition point, are satisfy | filled. When other components are contained, the total content is preferably 10 mol% or less.

The 50% particle size (D ₅₀ ) of the glass powder for substrate main body is preferably 0.5 to 2 μm. When the 50% particle size of the glass powder for substrate main body is less than 0.5 μm, the glass powder is likely to aggregate, making it difficult to handle and uniformly dispersing. On the other hand, when the 50% particle size of the glass powder exceeds 2 μm, the glass softening temperature may increase or the sintering may be insufficient. The particle size can be adjusted, for example, by classification as needed after pulverization.

As a ceramic filler, the well-known ceramic filler used for manufacture of a glass-ceramics board | substrate can be especially used without a restriction | limiting, For example, the mixture of an alumina powder, a zirconia powder, or an alumina powder and a zirconia powder can be used conveniently. The 50% particle size (D ₅₀ ) of the ceramic filler is preferably, for example, 0.5 to 4 μm.

  The substrate body glass powder and the ceramic filler are mixed and mixed so that the substrate body glass powder is 30 to 50% by mass and the ceramic filler is 50 to 70% by mass, for example. . A slurry is added to the composition for a substrate body by adding a binder, and if necessary, a plasticizer, a solvent and the like. This slurry is formed into a sheet by a doctor blade method or the like and dried to produce a green sheet.

  As the binder, polyvinyl butyral, acrylic resin, or the like can be used. As the plasticizer, for example, dibutyl phthalate, dioctyl phthalate, butyl benzyl phthalate and the like can be used. As the solvent, aromatic or alcoholic organic solvents such as toluene, xylene and butanol can be used. Furthermore, a dispersing agent and a leveling agent can also be used.

  The green sheet is cut into a predetermined dimensional angle using a punching die or a punching machine, and at the same time, an opening and a via hole for interlayer connection are punched and formed at a predetermined position. In the via hole for interlayer connection, a metal paste is filled by a method such as screen printing to form an unfired conductor portion that becomes a through conductor. Further, on the surface, a metal paste is printed as necessary by a method such as screen printing to form an unfired conductor portion that becomes the connection terminal 17, the external electrode terminal 18, and the reflective layer 21. As the metal 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, a solvent or the like as required, is used.

  Moreover, the glass paste used as the colored glass layer 22 is apply | coated to the surface of a green sheet, especially the surface of the part used as the mounting surface 11, as needed. The glass paste is composed of a colored glass composition containing a glass layer glass powder and a colorant as described above, for example. In the case where the glass paste is not applied to the surface of the green sheet, the colored glass layer 22 is formed by applying the glass paste after firing the substrate body 11.

  The green sheet on which the unfired conductor part is formed is, for example, superposed while being aligned, integrated by heating and pressing, and then held at a temperature of 500 to 600 ° C. for 1 to 10 hours, and included in the green sheet Degreasing is performed to decompose and remove the binder such as resin. Then, it hold | maintains for 20 to 60 minutes at the temperature of 850-900 degreeC, the board | substrate body composition which comprises a green sheet is baked, and the board | substrate body 11 is manufactured. By this firing, the unfired conductor portion is also fired at the same time, and the connection terminal 17, the external electrode terminal 18, the through conductor, and the reflective layer 21 are formed. Moreover, when the glass paste used as the colored glass layer 22 is apply | coated, a glass paste is baked and the colored glass layer 22 is formed.

  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.

Further, when the firing temperature is less than 850 ° C. and the firing time is less than 20 minutes, a dense product may not be obtained. On the other hand, if the firing temperature is about 900 ° C. and the firing time is about 60 minutes, a sufficiently dense product can be obtained, and if it exceeds this, productivity and the like may be lowered.
The firing temperature is more preferably 860 to 880 ° C. When a metal paste containing a metal powder containing silver as a main component is used to form the reflective layer 21, if the firing temperature exceeds 880 ° C., the metal paste may be excessively softened and cannot maintain a predetermined shape. There is.

  Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1
A light-emitting element mounting substrate and a light-emitting device having the structure shown in FIGS.

  First, glass powder for glass layer (manufactured by Asahi Glass Co., Ltd., trade name: ASF102Y) was prepared by grinding for 20 hours with an alumina ball mill. Note that ethyl alcohol was used as a solvent for grinding.

The average of the glass powder for glass layer particle diameter _{D 50} of the laser diffraction / scattering particle size distribution analyzer (manufactured by Shimadzu Corporation, trade name: SALD2100) was measured using a mean particle diameter _{D 50} is 2.5μm there were. Moreover, the softening point (Ts) of the glass powder for glass layers is heated up to 1000 degreeC on the conditions of the temperature increase rate of 10 degree-C / min using a differential thermal analyzer (Bulker AXS company make, brand name: TG-DTA2000). As a result, the softening point (Ts) was 775 ° C.

To 100 parts by weight of the glass layer glass powder, Bengala (Fe ₂ O ₃ ) having an average particle diameter D ₅₀ of 10 μm as a colorant is added so as to have a ratio of 5 parts by weight, and mixed, for glass layer It was set as the composition. Further, the glass layer composition was blended so that the proportion of the resin component was 60% by mass and the resin component was 40% by mass, kneaded for 1 hour in a porcelain mortar, and further dispersed three times with three rolls to obtain glass. A paste was prepared. As the resin component, ethyl cellulose and α-terpineol were prepared and dispersed at a mass ratio of 85:15.

  Separately, a glass powder for a substrate body (trade name: ASF 1860, manufactured by Asahi Glass Co., Ltd.) was prepared by pulverizing with an alumina ball mill for 40 hours. Note that ethyl alcohol was used as a solvent for grinding.

  A glass ceramic composition for a substrate body is produced by blending and mixing the glass powder for the substrate body to 40% by mass and the alumina filler (trade name: AL-45H, manufactured by Showa Denko KK) to 60% by mass. did. 50 g of this ceramic composition for a glass substrate body, 15 g of an organic solvent (a mixture of toluene, xylene, 2-propanol and 2-butanol in a mass ratio of 4: 2: 2: 1), a plasticizer (di-2 phthalate) -Ethylhexyl) 2.5g, polyvinyl butyral as a binder (trade name: PVK # 3000K, manufactured by Denka Co., Ltd.) 5g, and further a dispersant (trade name: BYK180, manufactured by Big Chemie) were mixed and mixed to prepare a slurry. . This slurry was applied onto a PET film by a doctor blade method and dried to produce a plurality of green sheets to be first to third main body portions.

  On the other hand, silver powder as a conductive 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 the solvent is set so that the solid content is 85 mass%. After being dispersed in α-terpineol, the mixture was kneaded in a porcelain mortar for 1 hour and further dispersed three times with three rolls to produce a metal paste.

  In the green sheet as the first main body, through holes are formed in a portion where the through conductors are formed using a hole punch, and a metal paste is filled by screen printing to form an unfired through conductor. Further, a metal paste was printed by a screen printing method to form unfired connection terminals and external electrode terminals. Moreover, the opening part was formed in the green sheet used as the 2nd main-body part so that it might become predetermined arrangement | positioning using the hole punch. Furthermore, the green sheet which becomes the third main body was punched out and processed into a frame shape. Such green sheets were stacked and integrated by thermocompression bonding.

  A silver paste was applied to almost the entire portion of the integrated green sheet mounting surface by screen printing to form an unsintered reflective layer (silver reflective layer). In addition, a silver paste (Daiken Chemical Co., Ltd., brand name: S400-2) and ethyl cellulose as a vehicle are blended at a mass ratio of 85:15 so that the solid content is 85 mass%. After being dispersed in α-terpineol as a solvent, the mixture was kneaded for 1 hour in a porcelain mortar, and further dispersed three times with a three roll. Furthermore, the said glass paste was apply | coated so that the whole unbaked reflection layer might be covered, and the unbaked colored glass layer was formed. Thus, an unfired light emitting element mounting substrate was manufactured.

  This unsintered light emitting element mounting substrate is degreased by holding at 550 ° C. for 5 hours, and further held at 870 ° C. for 30 minutes to perform baking, and the light emitting element mounting substrate having a colored glass layer on the mounting surface Manufactured.

  The light emitting element mounting substrate has a size of 5 mm in length × 5 mm in width, the diameter of the mounting surface is 4.40 mm, the diameter of the opening at the center of the mounting surface (second main body portion) is 1.11 mm, the outer periphery The diameter of the opening of the part was 0.50 mm. The thickness of the first main body was 0.40 mm, the thickness of the second main body was 0.10 mm, and the thickness of the third main body was 0.50 mm.

  The colored glass layer was formed to a thickness of 20 μm in a range of 3.88 mm in the vertical direction and 3.88 mm in the horizontal direction on the mounting surface (excluding the central and outer peripheral openings and the outer peripheral part). The reflective layer was formed in a shape slightly smaller than the colored glass layer. The color tone (reflection color tone) of the colored glass layer was red, and the chromaticity defined by the CIE (International Commission on Illumination) XYZ color system was x = 0.728 and y = 0.258. The colored glass layer 22 had a reflectance of 630 nm or less at a wavelength of 15% or less and a reflectance of 700 nm or more at a wavelength of 25% or more.

An InGaN LED chip with an emission peak wavelength of 450 nm is bonded to a predetermined position of the light emitting element mounting substrate with a silicone resin, and the electrode of the LED chip and the connection terminal of the light emitting element mounting substrate are electrically connected with an Au wire. did. Separately, a molding material was obtained by mixing 8.8 g of silicone resin, 0.84 g of YAG: Ce yellow phosphor, and 0.66 g of CaAlSiN ₃ red phosphor. This mold material was filled on the mounting surface of the light emitting element mounting substrate, heated at 150 ° C. for 2 hours, and the mold material was cured to manufacture a light emitting device.

(Comparative Example 1)
A light-emitting element mounting substrate and a light-emitting device were manufactured in the same manner as in Example 1 except that a glass paste prepared without adding Bengala (Fe ₂ O ₃ ) as a colorant was used. In addition, this light emitting element mounting substrate has a colorless glass layer on a reflective layer (silver reflective layer). The reflectance of the reflective layer was 90% or more in the visible light range of 400 to 760 nm.

  Next, a current of 350 mA was supplied to the light emitting devices of the examples and comparative examples to emit light, and the average color rendering index Ra and special color rendering index R9 to R14 were in accordance with JIS Z 8726 (method for evaluating the color rendering properties of the light source). Measured. The results are shown in Table 1.

  As is clear from Table 1, according to the light emitting device of the example in which the colored glass layer was provided on the mounting surface, the average color rendering index was compared with the light emitting device of the comparative example in which the non-colored glass layer was provided on the mounting surface. Ra was improved, and in particular, it was recognized that the special color rendering index R9 was greatly improved.

  DESCRIPTION OF SYMBOLS 10 ... Light emitting element mounting board | substrate, 11 ... Board | substrate main body, 12 ... Mounting surface, 14 ... 1st main body part, 15 ... 2nd main body part, 16 ... 3rd main body part, 17 ... Connection terminal, 18 ... External Electrode terminal, 21 ... reflective layer, 22 ... colored glass layer, 30 ... light emitting device, 31 ... light emitting element, 32 ... bonding wire, 33 ... molding material

Claims (10)

A substrate body having a mounting surface on which the light emitting element is mounted;
A light-emitting element mounting substrate comprising: a colored glass layer provided on a mounting surface of the substrate body.   The light-emitting element mounting substrate according to claim 1, wherein the colored glass layer contains a colorant.   The light-emitting element mounting substrate according to claim 2, wherein the colorant is an inorganic pigment.   The light-emitting element mounting substrate according to claim 3, wherein the inorganic pigment is Fe oxide. The light-emitting element mounting substrate according to claim 4, wherein the colored glass layer contains 1 to 10 mass% of the Fe oxide in terms of Fe ₂ O ₃ .   The light-emitting element mounting substrate according to claim 1, wherein the colored glass layer has a red color.   The light emitting element mounting substrate according to claim 1, further comprising a reflective layer on a mounting surface of the substrate body, wherein the colored glass layer is provided so as to cover the reflective layer.   The light-emitting element mounting substrate according to claim 1, wherein the colored glass layer has a thickness of 10 to 30 μm. The light emitting element mounting substrate according to any one of claims 1 to 8,
A light emitting element mounted on a mounting surface of the light emitting element mounting substrate;
And a molding material having a phosphor provided so as to cover the light emitting element.   The light emitting device according to claim 9, further comprising: a light emitting diode element that emits blue light as the light emitting element, and a yellow light emitting phosphor that emits yellow light by blue excitation as the phosphor.

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