JP2009182151A - Light emitting device and illuminator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device which is improved in heat dissipative property and suppresses a decrease in light emission efficiency. <P>SOLUTION: The light emitting device includes a light emitting element 3 and a substrate 1 which has a conductor 2 electrically connected to the light emitting element 2 and is provided with a through-hole (cut) 1a vertically penetrating the substrate in plan view, wherein the light emitting element 3 is disposed so as to close at least part of the through-hole (cut) 1a when the substrate is viewed in a plan. The light emitting device is characterized in that the light emitting element 3 is sealed with a light transparent member 6. Further, the light emitting device is characterized in that conductors 2 are disposed on both sides of a through-hole (cut) 1a when a substrate 1 is viewed in a plan. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light emitting device and a lighting device.

As a conventional light emitting device, for example, as shown in FIG. 5, a package 10 having a recess, a semiconductor light emitting element 30 mounted in the recess of the package 10, and a phosphor 70 disposed so as to cover the recess. (For example, refer to Patent Document 1).
JP 2001-345482 A

  However, in the above-described conventional light emitting device, light emitted from the semiconductor light emitting element to the bottom side of the recess of the package is reflected at the bottom of the recess of the package. Comparing the light intensity emitted to the opening side of the package recess with the light intensity emitted to the bottom side of the package recess, the light emitted to the bottom side of the package recess once reaches the bottom of the package recess. Since the light is reflected, the light emission efficiency of the semiconductor light emitting element cannot be sufficiently utilized due to the energy loss accompanying the reflection.

  The present invention has been devised in view of the above problems, and an object of the present invention is to provide a light-emitting device and a lighting device that fully utilize the light-emitting efficiency of a semiconductor light-emitting element.

  A light-emitting device according to an example of the present invention includes a light-emitting element and a conductor electrically connected to the light-emitting element, and a substrate provided with a notch or a through-hole so as to penetrate in the vertical direction in plan view. The light emitting element is disposed so as to close at least a part of the notch or the through hole when the substrate is viewed in plan.

  The light-emitting device according to an example of the present invention can provide a light-emitting device and a lighting device that fully utilize the light-emitting efficiency of the light-emitting element.

  Hereinafter, each component of the light emitting device according to an example of the present invention will be described.

  FIG. 1A is an external perspective view of a light-emitting device showing an embodiment of the present invention, and FIG. 1B is a cross-sectional structural view taken along the line AA ′ of FIG. FIG. 2 is a cross-sectional structure diagram of a light-emitting device showing another embodiment of the present invention. FIG. 3A and FIG. 3B are cross-sectional structural views of a lighting device showing an embodiment of the present invention. FIG. 4 is a cross-sectional structure diagram of an illumination device showing another embodiment of the present invention.

  In the figure, 1 is a substrate, 1a is a through hole (notch), 1b is a metal reflection layer, 2 is a conductor, 3 is a light emitting element, 4 is an adhesive, 5 is a wire, 6 is a translucent member, and 7 is a phosphor. 8 is a reflector, 8a is a light reflecting surface, 9 is a phosphor film, 10 is a transparent enclosing member, and 11 is a heat sink. As shown in FIG. 1B, a light emitting device according to an example of the present invention has a light emitting element 3 and a conductor 2 electrically connected to the light emitting element 3, and a through hole so as to penetrate in the vertical direction. The substrate 1 is provided with a (notch), and the light emitting element 3 is disposed so as to close at least a part of the notch or the through hole when the substrate 1 is viewed in plan.

According to such a configuration, it is possible to provide a light emitting device that sufficiently utilizes the light emission efficiency of the semiconductor light emitting element.
<Light emitting device>
(Light emitting element)
The kind of the light emitting element 3 is not specifically limited, The thing of arbitrary structures is employable. For example, the light emitting element 3 provided with a group III nitride compound semiconductor layer can be used.

  The light emitting element 3 is electrically connected through a conductor 2 provided on a substrate 1 described later. In the case of flip chip bonding, the conductor 2 and the light emitting element 3 are electrically connected by a conventionally known adhesive 4 such as a brazing material. In the case of wire bonding, the light emitting element 3 and the substrate 1 are electrically connected through the bonding wire 5.

  The periphery of the light emitting element 3 is preferably covered with a translucent member 6, and the light emitting element 3 can be protected from the outside.

  The translucent member 6 preferably has a refractive index between the light emitting element 3 and the outside (air) so that the light emitted from the light emitting element 3 is efficiently emitted to the outside. The translucent member 6 is preferably covered with a phosphor layer 7 containing a phosphor in a transparent film-like resin or the like, and the phosphor layer 7 converts the wavelength of light emitted from the light-emitting element 3. Any color such as white is emitted to the outside by color mixture due to light emission from the phosphor or color mixture between light emitting element 3 and light emission from the phosphor.

When the substrate 1 is viewed in plan, the light emitting element 3 is arranged so as to close at least a part of the notch or the through hole. The light emitting element 3 is placed inside a through hole (notch) of the substrate 1 described later. It may be located, or may be located on the upper surface or the lower surface of the through hole (notch) of the substrate 1.
(substrate)
The substrate is made of copper, copper alloy, copper clad material, aluminum, aluminum alloy, aluminum clad material, ceramic such as alumina, sapphire (single crystal alumina), aluminum nitride, quartz glass, borosilicate glass, Examples thereof include electrically insulating materials made of glass such as soda glass and resins such as epoxy resin and acrylic resin.

  As the material having electrical insulation, ceramic is particularly preferable because heat from the light emitting element 3 can be efficiently transmitted to the outside.

  A conductor 2 is formed on the substrate 1. In the case where the substrate 1 is made of a conductive material, the conductor 2 may be metallized via an electrically insulating material (for example, ceramics) in order to electrically insulate the substrate 1 and the light emitting element 3 from each other. Further, when the substrate 1 is made of an electrically insulating material, the metallization may be directly formed.

  The through hole (notch) 1a is provided so as to penetrate the substrate 1 in a vertical direction when seen in a plan view.

  As a method of forming the through hole (notch) 1a, when the substrate 1 is made of a conductive metal, machining using a drill or laser processing using laser light can be used. Further, when the substrate 1 is made of a dielectric material such as ceramics, the use of sandblasting can suppress cracks in the substrate 1.

  The shape of the through-hole (notch) 1a is preferably formed so as to spread from the light-emitting element 3 toward the surface of the substrate 1, and the radiation direction of the light-emitting element 3 as compared with the cylindrical through-hole (notch) 1a. By approaching to the color unevenness, color unevenness can be suppressed. Further, the light from the light emitting element 3 can be prevented from being irregularly reflected at the inner wall portion of the through hole (notch) 1a, and the light efficiency of the light emitting device can be improved.

  Moreover, it is preferable to have the metal reflection layer 1b in the inner wall part of the through-hole (notch) 1a. That is, when the substrate 1 is made of a conductive metal, the inner wall portion can be used as it is as the metal reflection layer 1b. However, when the substrate 1 is made of a dielectric material such as ceramics, light such as aluminum or silver can be used. The highly reflective metal reflective layer 1b can be formed by sputtering or vapor deposition. As a result, the amount of light (light intensity) absorbed by the inner surface of the through-hole 1a can be reduced, so that light loss can be reduced and light extraction efficiency (light emission efficiency) can be improved.

  Further, particularly when the substrate 1 is conductive, it is preferable that the conductor 2 is arranged on both sides of the through hole (notch) 1a with the substrate 1 in plan view. According to this configuration, it is possible to maintain a sufficient creepage distance between the conductors 2, and thus it is possible to suppress the occurrence of ion migration. As a result, the light emitting element 3 can be driven stably.

  More preferably, the through hole (notch) 1a preferably has an R surface or a C surface at the end of the surface on which the light emitting element 3 is disposed. That is, since the end portion of the surface on which the light emitting element 3 is disposed has the R surface or the C surface, the distance between the end portions can be easily maintained, so that the occurrence of ion migration can be further suppressed.

  Moreover, it is preferable that the board | substrate 1 is provided with several notch or a through hole, and the light utilization efficiency of the light emitting element 3 can be improved by providing the light emitting element 3 corresponding to each notch or through hole.

  More preferably, a plurality of through-holes 1 a are formed in the substrate 1, and the light-emitting elements 3 may be disposed in these adjacent through-holes 1 a so as to face the substrate 1. This is because the plurality of light emitting elements 3 can supplement each other with the amount of light emitted from the upper and lower surfaces thereof, and can be visually recognized from the outside as being balanced in the entire light emitting device (can prevent light color unevenness). is there. Therefore, it is preferable that there are an even number of through-holes 1a, that is, an even number of light-emitting elements 3. Further, the through-holes 1a are preferably formed in the substrate 1 at equal intervals.

  Furthermore, it is preferable that the notch or the through-hole 1 a is embedded with a translucent member 6 from the inside to the lower surface of the light emitting element 3, and the light emitting element 3 can be stably held by the translucent member 6.

  Furthermore, the translucent member 6 that embeds the upper surface of the light emitting element 3 is preferably formed in a dome shape. This is because light emitted from the upper surface of the light-emitting element 3 can be extracted uniformly to the periphery of the upper surface, so that light loss can be reduced and light extraction efficiency (light emission efficiency) is improved.

  Hereinafter, a light emitting device according to another embodiment of the present invention will be described.

  As shown in FIG. 2, the translucent member 6 preferably has the same length from the surface to the upper and lower surfaces of the light emitting element 3.

  In other words, since the number of portions where the optical path length when light emitted from the upper and lower surfaces of the light emitting element 3 passes through the inside of the translucent member 6 increases, the light intensity emitted to the outside of the translucent member 6 is increased. This is because it can be almost the same. Therefore, it can be visually recognized from the outside as being balanced as a whole, and light color unevenness can be prevented.

As shown in FIGS. 1B and 2, the surface of the translucent member 6 is preferably covered with a phosphor layer 7, and the light emitted from the light emitting element 3 is preferably fluorescent. Long wavelength conversion can be performed by the body layer 7.
<Lighting device>
The illuminating device concerning one Embodiment of this invention has the reflector 8, as shown to Fig.3 (a) and FIG.3 (b).

According to such a configuration, it is possible to provide an illumination device that sufficiently utilizes the light emission efficiency of the semiconductor light emitting element.
(Reflector)
The reflector 8 has a function of emitting light in all directions directed from a light emitting device in a fixed direction, and can improve light directivity.

  The material of the reflector 8 is preferably made of a material having high light reflectivity, such as silver, aluminum, and ceramics. Further, the light reflecting surface 8a may be formed on the surface of the reflector 8 by plating, vapor deposition, sputtering or the like using silver, aluminum or the like.

  The reflector 8 is preferably provided so that the light emitting element 3 is arranged at the center (on the center line of the reflector 8). As a result, the light emitted from the light emitting device can be radiated to the reflector 8 without any deviation, so that the light emitted from the reflector 8 in a certain direction can be visually recognized from the outside as being balanced as a whole (the color unevenness of the light). Can be prevented).

  Furthermore, the reflector 8 has a shape of a rotating paraboloid, and the light emitting element 3 is preferably positioned at the focal point. Thereby, since the light emitted from the light emitting device can be emitted as parallel light in the upward direction of the reflector 8, it is possible to prevent a reduction in light extraction efficiency due to internal reflection. In addition, a transparent encapsulating member 10 having the same or approximate refractive index of the translucent member 6 may be encapsulated inside the reflector 8.

  For example, as shown to Fig.3 (a), when it provides so that the translucent resin 6 may be covered, it can be set as the illuminating device which protected the light-emitting device more firmly from the external environment. Moreover, as shown in FIG.3 (b), when the transparent enclosure member 10 is provided without interposing the translucent member 6, since the number of processes can be less than FIG.3 (a) on a manufacturing process, it is preferable.

  Note that in both FIG. 3A and FIG. 3B, the light emitting device can be prevented from being damaged by an external impact.

  Further, since the transparent encapsulating member 10 is transparent, it can efficiently radiate the light emitted from the light emitting device to the outside. Note that the transparent encapsulating member 10 also functions as a placement portion on which the phosphor film 9 is placed when the phosphor layer 7 is not formed in the light emitting device. Then, by converting the light extracted from the light emitting device into a long wavelength with the phosphor film 9 formed at the interface with the outside, it becomes easy to extract the light converted into the long wavelength to the outside and the color rendering is improved. .

  In addition, it is preferable that the light emitting device is fixed to a heat radiating plate 11 made of a highly heat conductive material such as copper or aluminum. The heat generated from the light emitting element 3 is transmitted to the heat radiating plate 11 and an external substrate (not shown) via the substrate 1, and even if a large current is passed for the purpose of improving the light intensity of the light emitting element 3. It can always start normally.

  Moreover, as shown in FIG. 4, you may provide multiple light-emitting devices concerning one Embodiment of this invention. That is, as described above, a plurality of through-holes 1 a are formed in the substrate 1, and the light-emitting elements 3 are preferably disposed in the adjacent through-holes 1 a so as to face the substrate 1. This is because a plurality of light-emitting elements 3 can supplement each other with the amount of light emitted from the upper and lower surfaces thereof, and can be visually recognized from the outside as being balanced in the entire illumination device (can prevent light color unevenness). is there. Therefore, it is preferable that there are an even number of through-holes 1a, that is, an even number of light-emitting elements 3. Further, it is preferable that the through-holes 1a are formed on the substrate 1 at equal intervals.

(A) is an external appearance perspective view of the light-emitting device which shows one Embodiment of this invention, (b) is a cross-section figure in the AA 'cross section of Fig.1 (a). It is a cross-section figure of the light-emitting device which shows other embodiment of this invention. (A) is sectional structure drawing of the illuminating device which shows one Embodiment of this invention, (b) is sectional drawing of the illuminating device which shows other embodiment of this invention. It is a cross-section figure of the illuminating device which shows other embodiment of this invention. It is a sectional view showing a conventional light emitting device.

Explanation of symbols

1: Substrate 1a: Through hole (notch)
DESCRIPTION OF SYMBOLS 1b: Metal reflecting layer 2: Conductor 3: Light emitting element 4: Adhesive agent 5: Wire 6: Translucent member 7: Phosphor layer 8: Reflector 8a: Light reflecting surface 9: Phosphor film 10: Transparent encapsulating member 11: Heat sink

Claims (7)

A light emitting element;
A conductor having a conductor electrically connected to the light emitting element, and a substrate provided with a notch or a through hole so as to penetrate in the vertical direction in plan view;
Comprising
The light emitting device, wherein the light emitting element is disposed so as to close at least a part of the notch or the through hole when the substrate is viewed in plan.   The light emitting device according to claim 1, wherein the light emitting element is sealed with a translucent member.   3. The light emitting device according to claim 1, wherein the conductor is disposed on both sides of the substrate in plan view with the notch or the through hole interposed therebetween.   The light emitting device according to claim 1, wherein the substrate is provided with a plurality of the notches or the through holes.   5. The light emitting device according to claim 1, wherein the notch or the through hole is formed so as to widen away from the light emitting element.   The light emitting device according to claim 1, wherein the notch or the through hole has a metal reflection layer on an inner wall surface thereof. A light emitting device according to any one of claims 1 to 6,
A reflector provided to surround the light emitting device;
A lighting device comprising:

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