JP2011023767A - Light-emitting device, and lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly reliable light-emitting device the output of which is not reduced and the light-emitting characteristic of which is not changed, even when heat or impact from soldering and the like is applied. <P>SOLUTION: This light-emitting device 1 is equipped with: a light-emitting element 4; a translucent member 5 covering the light-emitting element 4; a reflective member 2 for reflecting light generated by the light-emitting element 4; and a wavelength conversion member 6 covering the translucent member 5 and containing a phosphor. The reflective member 2 has a porous structure where a plurality of particles of an inorganic material are partially integrated with one another, and also has a permeation region in which a part of the translucent member 5 permeates, and the permeation region surrounds the light-emitting element 4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a light emitting device and an illumination device that emit light emitted from a light emitting element to the outside.

  A light emitting device for housing a light emitting element 24 such as a conventional light emitting diode (LED) is shown in FIG. As shown in FIG. 9, the light emitting device 21 has a light emitting element 24 mounted on the center of the upper surface, and electrically connects the light emitting element 24 and the inside and outside of the light emitting element storage package (hereinafter also simply referred to as a package). A base 23 made of an insulator on which a wiring conductor (not shown) such as a lead terminal is formed, and a through hole for accommodating the light emitting element 24 at the center are formed by being bonded and fixed to the upper surface of the base 23. And a reflecting member 22 made of metal, resin, ceramics or the like.

  The substrate 23 is made of an aluminum oxide sintered body (alumina ceramic), an aluminum nitride sintered body, a mullite sintered body, ceramics such as glass ceramics, or a resin such as an epoxy resin. When the substrate 23 is made of ceramics, a wiring conductor (not shown) made of a metallized wiring layer is formed on the upper surface by baking a metal paste made of tungsten (W), molybdenum (Mo) -manganese (Mn), etc. at a high temperature. Is done. Further, when the base 23 is made of a resin, when the base 23 is molded, a wiring conductor (lead terminal) made of copper (Cu), iron (Fe) -nickel (Ni) alloy, or the like is provided inside the base 23 at one end. The part is fixed so as to protrude.

  The reflecting member 22 is made of a metal such as aluminum (Al) or Fe-Ni-cobalt (Co) alloy, ceramics such as an alumina sintered body, or a resin such as epoxy or polyphthalamide. It is formed into a cylindrical shape by a molding technique such as molding or extrusion molding. A through hole is formed in the center of the reflecting member 22 so as to expand outward as it goes upward. In addition, when improving the reflectance of the light of the internal peripheral surface of a through-hole, metals, such as Al, are adhered to this internal peripheral surface by the vapor deposition method or the plating method. The reflecting member 22 is bonded to the upper surface of the base 23 with a brazing material such as solder, silver brazing, or a resin adhesive. The reflection member 22 and the base body 23 may be separately manufactured and joined as described above, or may be integrally formed.

  Then, a wiring conductor (not shown) formed on the surface of the base 23 and the electrode of the light emitting element 24 are electrically connected via bonding wires, bumps, solder (both not shown), and the like, and then a reflecting member. Light is transmitted from the light-emitting element 24 by the wavelength conversion member 26 by injecting a light-transmitting member 25 inside the substrate 22 and thermally cured, and a wavelength conversion member 26 is disposed. The light has a desired wavelength spectrum. Can be formed with the light emitting device 21 that can take out the light.

  In FIG. 9, the function of the reflecting member 22 is to reflect the light emitted from the light emitting element 24 and to reflect the fluorescence emitted from the wavelength converting member 26, so that the reflectance of the inner peripheral surface of the reflecting member 22 is high. Is preferred. Therefore, when the inner peripheral surface of the reflecting member 22 is made of metal, aluminum, silver, rhodium or the like having high reflectivity is used. As a manufacturing method, a metal bulk material is formed into a shape of the reflective member 22 by cutting or pressing, or after molding a resin material or a glass material into the shape of the reflective member 12, at least the inner peripheral surface of the reflective member 22 There is a method of forming a reflecting surface by vapor-depositing aluminum, silver, rhodium or the like.

However, when the metal is exposed to the atmosphere, the surface is oxidized and the metallic luster is lost or colored, so that the reflectance of the reflecting surface often decreases. Further, when the surface roughness of the metal forming the reflecting member 22 is large, the surface area in contact with the air is increased, and thus the surface oxidation is likely to proceed. If the surface roughness of the metal forming the reflecting member 22 is smoothed, the reflectance is improved, but the difficulty of processing increases and the manufacturing cost increases.

  Because of these problems, a resin material in which a filler made of titanium oxide (titania) is dispersed is widely used as the material of the reflecting member 22. Since titania has a high refractive index and efficiently scatters light, the reflectance is high, and the light from the light emitting element 24 and the wavelength conversion member 26 can be favorably reflected. If these are used as the material of the reflecting member 22, a highly efficient light-emitting device 21 can be obtained.

JP 1999-29745 A

  However, part or all of the bonding interface between the reflecting member 22 and the translucent member 25 is caused by heat when the base 23 of the light emitting device 21 is electrically connected to the external electric circuit board by soldering or the like. May peel off. If part or all of the bonding interface between the reflective member 22 and the translucent member 25 is peeled off, light is confined in the generated gap or moisture enters the gap, resulting in a decrease in the output of the light emitting device 21. Or the light emission characteristics change.

  Further, when the temperature of the light emitting device driving circuit board (not shown) on which the light emitting device is mounted changes, the light emitting element 24 is heated by the heat conducted from the light emitting device driving circuit board to the light emitting element 24 through the base 23. The band gap of the active layer changes, and there is a problem that light having a stable luminous efficiency and a desired peak wavelength is not emitted from the light emitting element 24.

  Furthermore, when a temporary heat load is applied to the light emitting device, the base 23, the reflecting member 22, and the light transmitting member 25 are peeled off due to the thermal expansion or contraction of the light transmitting member 25, and the light emitting device. As a result, the long-term reliability of the light-emitting device deteriorates, and yellowing or other coloring occurs, resulting in deterioration of the transmittance of the translucent member 25 or a decrease in the light-emitting efficiency of the light-emitting device. It was.

  In addition, the base 23 and the reflecting member 22 are colored by heat from the light emitting element 24 and the light emitting device driving circuit board, and the reflectance of the surface is lowered, so that the light emitting efficiency of the light emitting device is lowered. Was.

  The present invention has been made in view of the above problems, and its purpose is that even when heat or impact due to soldering or an operating environment is applied, the output may decrease or the light emission characteristics may change. There is no need to provide a highly reliable light-emitting device.

The light-emitting device of the present invention includes a light-emitting element, a translucent member that covers the light-emitting element, a reflective member that reflects light generated by the light-emitting element, and a phosphor that covers the translucent member. The reflective member has a porous structure in which a plurality of particles of an inorganic material are partially integrated with each other and a part of the translucent member penetrates. And the penetration region surrounds the light emitting element.

The light-emitting device of the present invention includes a light-emitting element, a translucent member that covers the light-emitting element, a wavelength conversion member that covers the translucent member, and contains a phosphor, and the light-emitting element. A substrate having an upper surface, and the substrate has a porous structure in which a plurality of particles of an inorganic material are partially integrated with each other on the upper surface, and one of the translucent members. It has the penetration area | region which the part has penetrated.

  The light emitting device of the present invention has a light emitting element mounting portion on the upper surface, a light emitting element storage package in which a reflective member is formed so as to surround the light emitting element mounting portion, a light emitting element mounted on the mounting portion, A translucent member injected inside the reflecting member so as to cover the light emitting element, and at least one of the upper surface and the reflecting member is made of a porous material, and the translucent member has a part thereof Since it penetrates into the upper surface or the reflecting member and is bonded to the upper surface or the reflecting member, the translucent member and the upper surface or the reflecting member are bonded very firmly by the anchor effect, and soldering or operation There is no problem that a part or all of the substrate or the reflecting member and the translucent member is peeled off due to heat or impact of the environment or the like. As a result, the light output of the light emitting device does not decrease and the light emission characteristics do not change over a long period of time.

  Further, since the upper surface of the substrate or the reflecting member is made of a porous material, it has low thermal conductivity, and heat is transmitted from the light emitting device driving circuit board on which the light emitting device is mounted to the light emitting element via the substrate or the reflecting member. It can be difficult. That is, since a large number of voids are formed in the porous material, it is difficult for heat from the light emitting device driving circuit board to be conducted to the light emitting element through the porous material. As a result, it is difficult for the transmittance of the translucent member to deteriorate due to occurrence of yellowing or the like, and stable light output, luminous efficiency, and Light having a desired peak wavelength can be emitted from the light emitting element.

  In the light emitting device of the present invention, preferably, the light emitted from the light emitting element to the side is reflected on the inner side of the reflecting member because the inner peripheral surface of the reflecting member is an inclined surface that spreads outward as it goes upward. The light is reflected upward on the peripheral surface, and the luminance, illuminance, and light emission efficiency of the light emitting device can be further improved.

  In the light emitting device of the present invention, preferably, the upper surface or the reflecting member is made of a porous inorganic material having a porosity of 15 to 43%, so that an appropriate amount of pores is formed in the upper surface of the substrate or in the reflecting member. Can be formed into a base or a reflecting member having an appropriate strength, and the light-transmitting member can be appropriately permeated. In addition, since the inorganic material hardly changes in quality and has good environmental performance such as weather resistance, a highly reliable substrate or reflecting member can be obtained.

  In the light emitting device of the present invention, preferably, the upper surface or the reflection member is formed by connecting a plurality of pores and communicating with the inner surface of the upper surface or the reflection member. The light-transmitting member and the substrate or the reflecting member can be bonded very firmly by being easily penetrated into the pores and penetrating into the pores communicating in a complicated shape.

  The lighting device of the present invention includes the light emitting device of the present invention, a drive unit on which the light emitting device is mounted and having electric wiring for driving the light emitting device, and a light reflecting means for reflecting light emitted from the light emitting device. Therefore, it is possible to provide an illumination device that can obtain a uniform illuminance surface without lowering light output or changing light emission characteristics over a long period of time.

(A) is sectional drawing which shows the other example of embodiment of the light-emitting device of this invention, (b) is sectional drawing which expanded and displayed the reflection member typically. It is sectional drawing which shows the other example of embodiment of the light-emitting device of this invention. It is sectional drawing which shows the other example of embodiment of the light-emitting device of this invention. It is a top view which shows an example of embodiment of the illuminating device of this invention. It is sectional drawing of the illuminating device of FIG. It is a top view which shows the other example of embodiment of the illuminating device of this invention. It is sectional drawing of the illuminating device of FIG. It is sectional drawing of the conventional light-emitting device. It is a graph which shows the measurement result of a porosity and a reflectance, (a) shows a result when a measurement wavelength is 400 nm and (b) is a measurement wavelength of 600 nm.

  The light emitting device of the present invention will be described in detail below. FIG. 1A is a cross-sectional view showing an example of an embodiment of the light emitting device 1 of the present invention, and FIGS. 2 and 3 are other examples of the embodiment of the light emitting device 1 of the present invention. 1, 2, and 3, 2 is a reflecting member, 3 is a base, 4 is a light emitting element, 5 is a translucent member such as transparent resin or glass, and 7 is a translucent member 5 that penetrates the reflecting member 2. The light-emitting device 1 is mainly composed of the permeation layer. Reference numeral 6 denotes a wavelength conversion member comprising a transparent member containing a phosphor.

  The substrate 3 in the present invention is made of an aluminum oxide sintered body (alumina ceramic), an aluminum nitride sintered body, a mullite sintered body, ceramics such as glass ceramics, or a glass insulator or resin such as silica. A mounting portion 3 a for the light emitting element 4 is provided on the upper surface 3 b of the base 3 and functions as a support member that supports the light emitting element 4.

  Further, a wiring conductor or a metal wire made of a metallized wiring layer using a metal powder such as W, Mo, or Mn for electrically connecting the inside and outside of the light emitting device 1 is embedded in the surface or inside of the substrate 3. The wiring conductor (not shown) is formed, the electrode of the light emitting element 4 is electrically connected to the portion of the wiring conductor exposed on the upper surface 3b of the base 3, and the wiring exposed on the lower and side surfaces of the base 3 An external electric circuit (not shown) is connected to the conductor portion. Thus, the base 3 also functions as a substrate that connects the external electric circuit and the light emitting element 4.

  Alternatively, the exposed portion of the wiring conductor such as the lower surface of the base 3 is connected to an external electric circuit via a lead terminal made of a metal such as Cu or Fe—Ni alloy, a bump conductor (not shown), or the like. The Thereby, the light emitting element 4 is electrically connected to the external electric circuit through the wiring conductor.

  The wiring conductor should be coated with a metal with excellent corrosion resistance, such as Ni or gold (Au), with a thickness of about 1 to 20 μm on the exposed surface, which effectively prevents the wiring conductor from being oxidatively corroded. In addition to preventing this, it is possible to strengthen the electrical connection between the wiring conductor and the light emitting element 4 and the connection between the wiring conductor and a conductive adhesive member (not shown) such as solder or gold bump. Therefore, a Ni plating layer having a thickness of about 1 to 10 μm and an Au plating layer having a thickness of about 0.1 to 3 μm are sequentially deposited on the exposed surface of the wiring conductor by an electrolytic plating method or an electroless plating method. More preferred.

  In the light emitting device of the present invention, at least one of the upper surface 3b of the base 3 and the reflecting member 2 is made of a porous material, and the translucent member 5 allows a part thereof to penetrate into the upper surface 3b of the base 3. The permeation layer 7 or a permeation layer 7 in which a part of the permeation layer 7 is permeated into the reflection member 2 is joined to the upper surface 3 b of the base 3 or the reflection member 2. For example, FIG. 1A shows an example in which the reflecting member 2 is made of a porous material, and the permeation layer 7 of the translucent member 5 is formed on the inner peripheral surface of the reflecting member 2, and FIG. An example in which the reflecting member 2 and the base 3 are made of a porous material and the permeation layer 7 is formed on the inner peripheral surface of the reflecting member 2 and the upper surface 3 b of the base 3 is shown. In addition, the base 3 may be made of a porous material, and the permeable member 5 may be bonded to the upper surface 3b of the base 3 by forming the permeation layer 7 thereon.

When the permeation layer 7 is formed on the upper surface 3b of the substrate 3, at least the upper surface 3b is made of, for example, a porous material in which a plurality of particles are partially integrated with each other to form many voids between the particles. . As a result, when the translucent member 5 is injected inside the reflecting member 2, the translucent member 5 penetrates into the upper surface 3 b of the base 3 and the permeation layer 7 is formed. The penetrating layer 7 functions as an anchor of the translucent member 5, and the translucent member 5 and the upper surface 3b of the base 3 are firmly bonded. As a result, when a load due to heat or impact is applied, such as when soldering the wiring conductor of the substrate 3, the translucent member 5 and the substrate 3 are less likely to peel off, and a highly reliable light-emitting device is obtained. be able to.

  Further, since the substrate 3 is made of a porous material, the substrate 3 has low thermal conductivity, and it is difficult for heat to be transmitted to the light emitting element 4 through the substrate 3 from the light emitting device driving circuit board on which the light emitting device is mounted. That is, since a large number of voids 32 are formed in the porous material as shown in the schematic enlarged sectional view of FIG. 1B, heat from the light emitting device driving circuit board is formed. Is difficult to be conducted to the light emitting element 4 through the porous material. As a result, the light emitting element 4 can emit light having a stable light output, light emission efficiency, and a desired peak wavelength even with respect to a temperature change of the light emitting device driving circuit board.

  FIG. 1B is a schematic diagram showing an enlarged structure of the substrate 3 or the reflecting member 2, in which 31 indicates particles and 32 indicates pores (hereinafter also referred to as voids) formed between the particles 31. Examples of the base 3 or the reflecting member 2 include a material that scatters and reflects light by using the voids 32 generated between the particles 31 by pressing and solidifying the fluororesin particles 31 and firing them. Can be mentioned. This material has a high reflectivity for wavelengths in the visible region.

  Note that when the operating temperature changes, the light emitting element 4 changes the peak wavelength of emitted light, or the light emission efficiency (ratio of the light energy and the amount of light emitted from the light emitting element 4 to the input power to the light emitting element 4). ) Will change. Thereby, the color of the light emitted from the light emitting device changes, or the light output and the light emission efficiency change. Therefore, in order to stabilize the operational characteristics such as the light output, light emission efficiency, and peak wavelength of the light emitting element 4, it is necessary to stabilize the temperature of the light emitting element 4 at a constant level.

  The base body 3 may be provided with a porous material at least on a part of the upper surface 3b including the mounting portion 3a on which the light emitting element 4 is mounted, and in the same manner as described above, from the light emitting device driving circuit board through the base body 3. Thus, it becomes difficult for heat to be transmitted to the light emitting element 4. Needless to say, the entire substrate 3 may be made of a porous material.

  When the permeation layer 7 is formed on the reflecting member 2, at least the inner peripheral surface 2a is made of, for example, a porous material in which a plurality of particles are partially integrated with each other to form many voids between the particles. It is formed in a cylindrical shape having through holes in the vertical direction. Preferably, in order to make light easily reflected upward on the inner peripheral surface 2a of the through hole, as shown in FIG. 1A, FIG. 2, and FIG. 3, the through hole that expands outward as it goes upward. It is said. Then, the lower surface of the reflecting member 2 is bonded and fixed to the upper surface 3b of the base 3 with a resin adhesive or the like, so that a recess surrounded by the upper surface 3b of the base 3 and the inner peripheral surface 2a of the through hole of the reflecting member 2 is formed. It is formed. Thereafter, an uncured transparent resin or the like that becomes the translucent member 5 is injected into the recess, and the translucent member 5 is cured by photocuring by room temperature curing, heat curing, light irradiation, or the like.

  Further, the reflecting member 2 is emitted from the light emitting element 4 to the side because the inner peripheral surface 2a disposed so as to surround the light emitting element 4 is an inclined surface that spreads outward as it goes upward. The light is reflected upward by the inner peripheral surface 2a, and the luminance, illuminance, and luminous efficiency of the light emitting device are improved. That is, the light diffusely reflected by the inner peripheral surface 2a is confined inside the light emitting device as compared with the case where the inner peripheral surface 2a is a vertical surface or a reflecting surface formed so as to narrow toward the upper side. Therefore, the light from the light emitting element 4 is efficiently emitted to the outside of the light emitting device, and the light output and the light emitting efficiency of the light emitting device are increased.

  In the light emitting device of the present invention, the substrate 3 or the reflecting member 2 is formed by injecting a translucent member 5 such as uncured silicone resin or epoxy resin into the void 32 of the porous material. 3 or the penetration member 7 is formed by allowing the translucent member 5 to permeate into the gap 32 near the surface of the through hole of the reflecting member 2 and then curing the resin. At this time, after injecting the uncured resin to be the translucent member 5, pressure is applied to the surface, or after injecting the uncured resin under reduced pressure, heat curing or room temperature curing under atmospheric pressure, light irradiation When the photocuring is performed by, for example, curing, the penetration layer 7 can be easily formed.

  Thus, the translucent member 5 filled inside the reflecting member 2 and the resin of the osmotic layer 7 are integrally formed, so that the osmotic layer 7 functions as an anchor of the translucent member 5, The translucent member 5 and the base 3 or the reflecting member 2 are firmly bonded. As a result, when a load due to heat or impact is applied, such as when the wiring conductor of the base 3 is soldered, the translucent member 5 and the base 3 or the reflecting member 2 are less likely to be peeled off, and the reliability is high. A light emitting device can be obtained.

  Furthermore, it is preferable that the plurality of gaps 32 in the base 3 or the reflecting member 2 are integrated so that they are partially connected to each other, and the surface of the base 3 or the reflecting member 2 and the inner gap 32 are communicated with each other. . Thus, by communicating from the surface of the base | substrate 3 or the reflection member 2 to the space | gap 32 deep inside, the thickness of the osmosis | permeation layer 7 becomes thick and the anchor effect by the osmosis | permeation layer 7 becomes large. Further, when the gap 32 in the base 3 or the reflecting member 2 communicates with the outside, the translucent member 5 penetrates into the gap 32 in the base 3 or the reflecting member 2 from the surface to the inside. Alternatively, when the osmotic layer 7 is formed on the reflecting member 2, gas such as air in the gap 32 is easily discharged quickly, so that the osmotic layer 7 can be easily formed.

  Moreover, it is preferable that the thickness of the osmosis | permeation layer 7 is 50 micrometers or more and 1000 micrometers or less. When the thickness of the osmotic layer 7 is less than 50 μm, it is difficult to exert a sufficient anchor effect. Further, when the depth at which the translucent member 5 penetrates from the surface of the substrate 3 or the reflecting member 2 is 1000 μm or more, total reflection caused by the difference in refractive index at the interface between the void 32 and the particle 31 between the particles 31 occurs. In the permeation layer 7, the difference in refractive index is small, so the permeation layer 7 is small, and the reflectance of the substrate 3 or the reflecting member 2 is lowered. Therefore, the depth at which the translucent member 5 penetrates from the surface of the substrate 3 or the reflecting member 2 is preferably 1 μm or more and less than 1000 μm.

  The substrate 3 or the reflecting member 2 is a porous material having a large number of voids 32 by integrating particles 31 of inorganic material such as alumina, yttria, zirconia, titania, diamond, calcium oxide, and barium sulfate in a part of each other. It is preferable that it is formed.

  The base 3 or the reflecting member 2 does not need to be entirely formed of a porous member, and is formed on the inner peripheral surface 2a of the through hole of the base 3 or the reflecting member 2 at least to a depth that allows the translucent member 5 to penetrate. It only has to be done.

When the substrate 3 or the reflecting member 2 is composed of particles 31 partially integrated with each other, the light incident on the surface of the particle 31 at an angle smaller than the total reflection angle is transmitted through the surface, and the inside of the particle 31 Enter. This transmitted light reaches the opposite surface after passing through the particles 31, and is totally reflected by the difference in refractive index at the interface between the surface and the gap 32 having a lower refractive index than that of the substrate 3 or reflected. The light can be emitted to the outside of the member 2. That is, when the interface between the particle 31 and the gap 32 exists at an angle that totally reflects the light incident angle, the incident light is totally reflected. On the other hand, when the interface between the particle 31 and the void 32 does not exist at an angle that totally reflects the light incident angle, the incident light is transmitted, but the particle 31 and the void 32 are located at the end of the optical path of the transmitted light. There are several interfaces, and among these interfaces, there is a high probability that there is an interface that exists at an angle of total reflection with respect to the light incident angle. As a result, the transmitted light that has entered the inside of the base 3 or the reflecting member 2 is totally reflected at any interface and is emitted to the outside of the base 3 or the reflecting member 2. When such a phenomenon occurs continuously, the transmitted light that has entered the base 3 or the reflecting member 2 is effectively reflected and emitted to the outside of the base 3 or the reflecting member 2. The total reflection angle means an angle equal to or greater than a critical angle formed by a line perpendicular to the interface when the light incident on the interface with the void 32 from the particle 31 side does not travel to the void 32 and the incident light. To do.

  As can be understood from the above action, from the viewpoint of efficiently reflecting incident light, it is preferable to use the inorganic particles 31 having a high refractive index and a large total reflection angle. Further, from the viewpoint of reducing light attenuation in the substrate 3 or the reflecting member 2, it is preferable to use an inorganic material that has little absorption with respect to light to be reflected (for example, the light absorption rate is 5% or less). In addition, it is preferable to use a material having a low refractive index as the translucent member 5, so that, in the permeation layer 7, light can be transmitted at the interface between the particles 31 and the translucent member 5 penetrating into the voids 32. Total reflection can be easily generated.

  Among these inorganic materials, from the viewpoint of refractive index, those that can ensure a large total reflection angle, such as titania (rutile; n = 2.8) or zirconia (n = 2.1) are particularly preferable.

The inorganic material can be selected according to the wavelength of light to be reflected from the viewpoint of light absorption (transmittance). For example, titania is preferable from the viewpoint of refractive index, but the wavelength of light is 350 nm.
It has the property of absorbing light in the front and back near ultraviolet region. Therefore, in order to configure the base 3 or the reflecting member 2 so as to reflect near-ultraviolet light having a wavelength of around 350 nm, it is preferable to use alumina that hardly absorbs near-ultraviolet light.

  In general, when the particle size of the particle 31 is smaller than the wavelength of the incident light, the interaction between the light and the particle 31 is reduced, so the effect of reflecting light at the interface between the particle 31 and the void 32 is small. Become. In particular, when the particle diameter is less than ¼ of the wavelength of light, the effect of reflecting light becomes very small. Therefore, it is preferable that the particle 31 made of the inorganic material used in the present invention has a particle size that is larger than ¼ of the wavelength of light incident on the substrate 3 or the reflecting member 2 and as small as possible.

  In addition, since this inorganic material improves the overall reflectivity by having a large number of spatially reflecting surfaces, when the particle size of the inorganic particles is too large, the particles 31 and voids 32 per unit space. The number of reflecting surfaces formed by contact with each other decreases, which is not preferable. Furthermore, from the viewpoint of increasing the probability of total reflection of incident light, it is preferable to use an irregular shape such as a plate shape or a column shape as the inorganic particle 31 rather than a spherical shape.

  The base 3 or the reflecting member 2 is formed so as to have a porosity of 15 to 43% in order to reflect and emit the transmitted light that has entered the base 3 or the reflecting member 2 with high probability. Is preferred. This is because, when the porosity is unreasonably small or unreasonably large, the gap 32 is reduced, so that the number of reflecting surfaces contributing to light reflection is reduced, and a good penetration layer 7 is difficult to be formed. This is because, when the porosity is unduly increased, the strength of the substrate 3 or the reflecting member 2 is lowered.

  As can be seen from FIGS. 9 (a) and 9 (b), the reflective member using alumina particles exhibits a high reflectance in the range of porosity of 10 to 45% regardless of the measurement wavelength. In particular, when the porosity is in the range of 15 to 43%, the reflectance is higher than that of a standard reflector (trade name “Spectralon”) manufactured by Labsphere, which is used as a comparative example. Therefore, when the reflecting member is formed using alumina, it can be said that the porosity is preferably set in the range of 15 to 43%.

  Here, the porosity is defined by the following mathematical formula 1.

  The bulk density in Formula 1 can be measured by the Archimedes method, and the true density can be measured by the gas phase substitution method (pycnometer method). If the porous part is thin, observe the cross section of the reflective layer with a microscope, find the area ratio of pores in the cross section (obtained by dividing the total area of the pores by the total area), and determine the area ratio of the pores. The porosity can be obtained by raising the power to 3/2.

  Such a base 3 or the reflecting member 2 can be formed by forming particles 31 made of a plurality of inorganic materials into the shape of the base 3 or the reflecting member 2 and then pre-baking. Note that pre-firing is different from a sintered body (ceramic) in which there are almost no voids between particles 31 made of an inorganic material (porosity is about 0.001 to 1%), and a porous material having an appropriate porosity. It means incomplete firing to form a mass.

  The temporary firing of the particle 31 layer made of an inorganic material is usually performed at 1000 to 1400 ° C. for 1 to 5 hours, depending on the inorganic material to be used, the porosity to be achieved and the bending strength. In the preliminary firing, an auxiliary agent for lowering the sintering temperature may be added. Examples of the auxiliary agent used in this case include calcia and magnesia, and the addition amount is 1 to 10% by mass.

  By performing such preliminary firing, the particles 31 made of an inorganic material are integrated with each other, and have an appropriate porosity and bending strength, for example, a porosity of 15 to 43% and a bending strength of 1 to 300 MPa. A porous body can be obtained. When the binder resin is contained in the particle 31 layer made of an inorganic material, the binder resin is removed by transpiration or combustion by heating in the pre-baking.

  The substrate 3 or the reflecting member 2 made of the particles 31 made of these inorganic materials scatters light by using the voids 32 formed between the particles 31 by pressing the fluoric resin particles 31 and firing them. Compared with the material to reflect, since it has a high reflectance, the light-emitting device 1 with higher luminous efficiency can be obtained. Further, when the substrate 3 or the reflecting member 2 is formed of an inorganic material, the light emitted from the light-emitting element 4 is colored due to its absorption characteristics, or the inorganic material is also excellent in heat resistance, so that it is carbonized when used at a high temperature. Therefore, the light emitting device 1 with high reliability can be obtained.

  Further, when the base 3 or the reflecting member 2 is prepared by pre-baking, the inorganic material particles 31 are press-molded, and a plurality of particles 31 are partially integrated with each other to form voids 32 between the particles 31. Since the process and the subsequent pre-baking process can be separated, the base body 3 or the reflecting member 2 is obtained by forming the base body 3 or the reflecting member 2 in a large amount with a press molding machine and then pre-baking it at once. Therefore, the base 3 or the reflecting member 2 can be efficiently manufactured at a low cost.

Next, the light emitting element 4 is made of, for example, gallium (Ga) -aluminum (Al) -nitrogen (N), zinc (Zn) -sulfur (S) on a transparent substrate such as sapphire by liquid phase growth method, MOCVD method, or the like. Zn-selenium (Se), silicon (Si) -carbon (C), Ga-phosphorus (P), Ga-A
An LED or the like in which a semiconductor such as l-arsenic (As), Al-indium (In) -Ga-P, In-Ga-N, Ga-N, or Al-In-Ga-N is formed as a light-emitting layer is used. . Examples of the semiconductor structure include a homo structure having a MIS junction and a pn junction, a hetero structure, and a double hetero structure. These light emitting elements 4 can select various emission wavelengths from ultraviolet light to infrared light depending on the material of the semiconductor layer and the degree of mixed crystal. The transparent substrate is used for the purpose of supporting the semiconductor on which the light emitting layer is formed.

  The light emitting element 4 is connected to a wiring conductor formed on the mounting portion 3a of the base 3 by flip chip bonding via a conductive adhesive member (not shown) such as Au—Sn eutectic solder. Mounted on the substrate 3. Alternatively, it is attached to the mounting portion 3a of the base 3 with an inorganic adhesive such as solder, sol-gel glass or low melting glass, or an organic adhesive such as epoxy resin, and the electrode of the light emitting element 4 is located near the mounting portion 3a via a bonding wire. It is electrically connected to the wiring conductor.

  The translucent member 5 is preferably a transparent material having a transmittance of 95% or more with respect to light emitted from the light emitting element 4 and a refractive index close to that of the transparent substrate forming the light emitting element 4. For example, silicone resin with phenyl group introduced, silicone resin in which titania or zirconia nanoparticles (particle size less than 50 nm) are uniformly dispersed, epoxy resin, organic-inorganic hybrid material having titania or zirconia in the skeleton, tin phosphorus Low melting glass, transparent polyimide resin, etc. can be used.

  Since it is preferable to use a resin having a low refractive index for the permeation layer 7, the resin is used around the light emitting element 4, and the resin around the base 3 or the reflecting member 2 is a resin having a high adhesion with the resin and is refracted. A multilayer structure using a resin 5a having a low refractive index such as a fluorine resin having a low refractive index may be used (see FIG. 3). For example, a resin 5a having a low refractive index is infiltrated into the surface of the reflecting member 2 on the inner peripheral surface 2a of the reflecting member 2, and is covered so as to cover the upper surface 3b of the base 3 or the inner peripheral surface 2a of the reflecting member 2. The light transmissive member 5 may be formed by injecting the resin so as to cover the light emitting element 4. Thereby, the light from the light emitting element 4 is reflected according to Snell's law at the interface between the translucent member 5 and the low refractive index resin 5a, and the light loss generated according to the reflectance of the permeation layer 7 is suppressed. The light output and luminous efficiency of the light emitting device are improved.

  The transparent member used for the wavelength conversion member 6 needs to select a material that is transparent to both the light emitted from the light emitting element 4 and the fluorescence emitted from the phosphor (not shown) contained in the wavelength conversion member 6. For example, silicone resin, epoxy resin, urea resin, fluorine resin, sol-gel glass, organic-inorganic hybrid material, low melting point glass, transparent polyimide resin, and the like can be used.

As the phosphor, various materials that can be excited by the light of the light emitting element 4 and emit light of different wavelengths are used. For example, La ₂ O ₂ S that emits red (about 580 to 780 nm) fluorescence. : Eu, Y ₂ O ₂ S: Eu, LiEuW ₂ O ₈ , Y ₃ Al ₅ O ₁₂ that emits yellow (about 480 to 700 nm) fluorescence: Ce, green (about 450 to 650 nm) fluorescence is emitted ( BaMgAl) ₁₀ O ₁₂ : Eu, Mn, ZnS: Cu, Al, SrGa ₂ S ₄ : Eu, BaMgAl ₁₀ O ₁₂ : Eu, (Sr, Ca, Ba, Mg) generating blue (about 420 to 550 nm) fluorescence _{) 10 (PO 4) 6 C} l2: Eu or the like is used.

  Further, the wavelength conversion member 6 is formed so as to cover the translucent member 5, and as the installation method thereof, after the wavelength conversion member 6 containing the phosphor in the transparent member is formed into a desired shape in advance. By placing the phosphor and the transparent member on the translucent member 5 or after kneading the phosphor and the transparent member, the liquid wavelength conversion member 6 is used as a precursor on the translucent member 5 using a dispenser. After being applied to the thickness of the film, it is cured by heat curing in an oven or by irradiation with ultraviolet rays.

  Note that the wavelength conversion member 6 can be omitted when the light emitting element 4 having a light emission peak in the ultraviolet to blue light region is used and it is not necessary to convert the light emission into a wavelength such as white light.

  In addition, the lighting device of the present invention is configured such that one light emitting device 1 of the present invention is installed in a predetermined arrangement and the light emitting device 1 of the present invention is used as a light source, or a plurality of the light emitting devices 1 The light emitting device of the present invention is installed in a predetermined arrangement such as a plurality of circular or polygonal light emitting device groups formed of a lattice shape, a staggered shape, an emission shape, or a plurality of light emitting devices. By using 1 as a light source, a lighting device can be obtained. A lighting device using light emission by recombination of electrons of the light-emitting element 4 made of a semiconductor can have lower power consumption and longer life than a conventional lighting device using discharge, and is a small-sized illumination with less heat generation. It can be a device.

  In addition, the light emitting device 1 of the present invention is installed in a predetermined arrangement as a light source on a driving unit having an electric wiring on which the light emitting device 1 is mounted and driven, and an optical design in an arbitrary shape around the light emitting device 1 By installing light reflecting means such as a reflecting plate, an optical lens, or a light diffusing plate, an illuminating device that can emit light having an arbitrary light distribution can be obtained.

  For example, as shown in FIG. 5 and FIG. 6, a plurality of light emitting devices 101 are arranged in a plurality of rows on a driving unit 102 such as a light emitting device driving circuit board, and an arbitrary shape is formed around the light emitting device 101. In the case of an illuminating device in which light reflecting means 103 such as an optically designed reflector is installed, adjacent light emitting devices 101 are arranged between a plurality of light emitting devices 101 arranged on adjacent rows. It is preferable to use a so-called staggered arrangement. When the light emitting device 101 is arranged in a grid, the glare is strengthened by arranging the light emitting device 101 as a light source on a straight line, and when such a lighting device comes into human vision, Whereas discomfort is likely to occur, the staggered pattern can suppress glare and reduce discomfort to the human eye.

  In addition, since the distance between the adjacent light emitting devices 101 is increased, thermal interference between the adjacent light emitting devices 101 is effectively suppressed, and heat is accumulated in the light emitting device driving unit 102 in which the light emitting devices 101 are mounted. Is suppressed, and heat is efficiently dissipated outside the light emitting device 101. As a result, it is possible to manufacture a long-life lighting device that hardly causes discomfort to the human eye and has stable optical characteristics over a long period of time.

  In addition, the lighting device is a concentric arrangement of a circular or polygonal light emitting device 101 group composed of a plurality of light emitting devices 101 on the light emitting device driving unit 102 as shown in the plan view and the sectional view shown in FIGS. In the case of a plurality of groups of lighting devices, it is preferable to increase the number of light emitting devices 101 arranged in one circular or polygonal light emitting device 101 group toward the outer peripheral side from the center side of the lighting device. Thereby, it is possible to arrange more light emitting devices 101 while maintaining an appropriate interval between the light emitting devices 101, and it is possible to further improve the illuminance of the lighting device. Further, it is possible to reduce the density of the light emitting device 101 in the central portion of the lighting device, and to suppress heat accumulation in the central portion of the light emitting device driving unit 102. Therefore, the temperature distribution in the light emitting device driving unit 102 becomes uniform, heat is efficiently conducted to the external electric circuit board or the heat sink on which the lighting device is installed, and the temperature rise of the light emitting device 101 can be suppressed. As a result, the light-emitting device 101 can operate stably over a long period of time, and a long-life lighting device can be manufactured.

Examples of such lighting devices include general lighting fixtures, chandelier lighting fixtures, residential lighting fixtures, office lighting fixtures, store lighting, display lighting fixtures, and street lamp lighting fixtures that are used indoors and outdoors. , Guide lights, signal equipment, stage, studio lighting, advertising lights, lighting poles, underwater lighting, strobe lights, spotlights, security lights embedded in power poles, emergency lighting, flashlights , Electronic bulletin boards, etc., backlights for dimmers, automatic flashers, displays, etc., illumination of moving image devices, ornaments, illuminated switches, optical sensors, medical lights and in-vehicle lights.

  The light emitting device 1 of the present invention was evaluated as follows.

  First, the reflecting member 2 is formed by a cutting method using a material that scatters and reflects light by utilizing the voids 32 formed between the particles 31 by pressing and solidifying the particles 31 made of a fluorine-based resin. did. Moreover, a silicone resin was prepared as the translucent member 5. Next, among the reflecting members 2 formed of a material that scatters and reflects light using the voids 32 formed between the particles 31 by pressing and solidifying the particles 31 made of a fluorine resin, the light emitting element The depth in which the silicone resin is soaked into the inner peripheral surface 2a of the through hole where the light of No. 4 and the light of the phosphor are reflected, that is, the thickness of the permeation layer 7 is changed. In addition, the thickness of the osmosis | permeation layer 7 was made into 4 types, 1100 micrometers, 900 micrometers, 50 micrometers, and 10 micrometers. The thickness of the osmotic layer 7 was controlled at a temperature at which the reflective member 2 was preheated before the silicone resin was soaked.

  Also, as the substrate 3, a mounting portion 3a made of white alumina ceramics and a substrate 3 on which a wiring conductor was formed were prepared, and the light emitting element 4 was flip-chip mounted on the mounting portion 3a of the light emitting element 4 with gold bumps. Next, the reflective member 2 soaked with a silicone resin so as to surround the light emitting element 4 is attached to the upper surface 3b of the base 3 with an epoxy adhesive, and then the same silicone resin as the silicone resin soaked into the reflective member 2 is applied to the reflective member 2. Was filled in and thermally cured at 150 ° C. for 1 hour to produce a light emitting device 1.

  Next, Table 1 shows the result of measuring the light output of the light-emitting device 1 having four types of the osmotic layer 7 produced.

  From the results shown in Table 1, when the penetration depth of the silicone resin, that is, the thickness of the permeation layer 7 is 1100 μm, the light output of the light-emitting device 1 is greatly reduced to 82%, assuming that the permeation layer 7 has a light output of 50 μm as 1. . This is because the silicone resin is applied to the reflecting member 2 made of a material that scatters and reflects light by utilizing the voids 32 formed between the particles 31 by pressing and solidifying the particles 31 made of fluorine resin. Since the silicone resin having a refractive index 1.41 larger than the refractive index 1.3 of the fluororesin is buried in the void 32 between the fine particles 31 made of the fluororesin constituting the reflecting member 2 because of excessive penetration, this reflective material is originally It is considered that the reflectance of the light emitting device 1 is impaired, the light energy of the light emitting element 4 cannot be efficiently reflected by the reflecting member 2, and the light output of the light emitting device 1 is reduced.

  Next, the prepared four types of light emitting devices 1 were put into a solder reflow furnace. The temperature condition was set so that the peak temperature was maintained at 260 ° C. or higher and lower than 280 ° C. for 10 seconds and then returned to room temperature in 60 seconds. The furnace atmosphere was a nitrogen atmosphere.

  Table 2 shows the results of measuring the light output after the reflow furnace was introduced.

  From the results in Table 2, when the depth at which the silicone resin is soaked is 10 μm, the light output of the light-emitting device 1 is greatly reduced to 72% with respect to the light output of the penetration layer 7 of 50 μm. This is because the silicone resin presses and solidifies the particles 31 made of a fluororesin, and then baked to make the reflecting member 2 formed of a material that scatters and reflects light using the voids 32 formed between the particles 31. Since the penetration depth is not deep enough, when the silicone resin filled on the inner surface of the reflecting member 2 formed of the reflecting material is cured, the reflecting member 2 and the silicone resin are in close contact with each other, but the anchor effect is sufficient. The light-transmitting member 5 is peeled off from the reflecting member 2 due to the stress generated due to the difference in thermal expansion between the reflecting member 2 and the silicone resin, and the light output of the light emitting device 1 is reduced. it is conceivable that.

  Therefore, it was found that the depth of the permeation layer 7 is preferably 50 μm or more and 900 μm or less.

  It should be noted that the present invention is not limited to the above-described embodiments and examples, and various modifications can be made without departing from the scope of the present invention. For example, the reflecting member 2 is not only formed in a cylindrical shape with a through-hole, but also may have a U shape with one side open in the top view plane, or cut in one side in the cross section. It may be formed as a key shape having a notch, so-called side view reflecting member 2.

  Moreover, the lighting device of the present invention is not limited to one in which a plurality of light emitting devices 1 are installed in a predetermined arrangement, but may be one in which one light emitting device is installed in a predetermined arrangement.

1: Light-emitting device 2: Reflective member 3: Base 3a: Mounting portion 4: Light-emitting element 5: Translucent member 6: Wavelength converting member 7: Penetration layer

Claims (6)

A light emitting element;
A translucent member covering the light emitting element;
A reflective member that reflects light generated by the light emitting element;
The light-transmitting member is covered and a wavelength conversion member containing a phosphor is provided,
The reflective member has a porous structure in which a plurality of particles of an inorganic material are partially integrated with each other, and has a penetrating region through which a part of the translucent member penetrates, The light-emitting device, wherein the permeation region surrounds the light-emitting element. The light emitting device according to claim 1, wherein the wavelength conversion member is surrounded by an inner peripheral surface of the reflection member. The light-emitting device according to claim 1, wherein the permeation region has a porosity of 15 to 43%. A light emitting element;
A translucent member covering the light emitting element;
While covering the translucent member, a wavelength conversion member containing a phosphor,
A base having an upper surface on which the light emitting element is mounted;
The base has a porous structure in which a plurality of particles of an inorganic material are partially integrated with each other on the upper surface, and has a permeation region through which a part of the translucent member permeates. A light emitting device characterized by that. The light emitting device according to claim 4, wherein the wavelength conversion member is surrounded by an inner peripheral surface of the reflection member. The light-emitting device according to claim 4, wherein the permeation region has a porosity of 15 to 43%.

Images