JPWO2010123052A1 - Light emitting device - Google Patents

Abstract

The present invention provides an LED light-emitting device capable of efficiently releasing heat of a wavelength conversion member containing a phosphor, and a substrate having a recess opened at an upper end surface, and a bottom surface of the recess. A mounted LED element, a translucent member that seals the LED element, a wavelength conversion member that contains a phosphor and is placed on the translucent member, and on the wavelength conversion member A translucent heat radiating member that is placed and covers the opening of the recess.

Description

  The present invention relates to an LED light emitting device that emits light emitted from an LED element after wavelength conversion by a phosphor layer.

  Conventionally, light emission that emits light of a color different from that of LED elements such as white by combining LED elements that emit blue light or ultraviolet light with various phosphors using a gallium nitride compound semiconductor An apparatus has been developed (Patent Document 1). Such a light emitting device using an LED element has advantages such as small size, power saving and long life, and is widely used as a light source for display and a light source for illumination. In particular, recently, LED elements with high output and high brightness have been developed, and their uses are increasing more and more.

  By the way, when the output of the LED element is increased, the amount of heat generated by the LED element is greatly increased, and the LED element itself is deteriorated by the heat. Further, since the phosphor is also vulnerable to heat, it is generally said that the phosphor is thermally deteriorated by heat transfer from the LED element.

  Therefore, conventionally, a heat sink is laid under the LED element to dissipate heat from here.

JP-A-7-99345

  However, in reality, the present inventors have discovered for the first time through intensive studies the fact that the phosphor emits heat and promotes its own deterioration. When the LED element was mounted on a heat dissipation substrate, covered with a transparent resin layer, and further covered with a phosphor layer, an experiment was conducted under conditions of an applied voltage of 3.5 V and a current of 300 mA. The temperature of the upper surface of the phosphor layer is 65 ° C. even though the portion is 85 ° C. and the temperature is lowered to 55 ° C. on the upper surface of the transparent resin layer. It was confirmed that the exotherm of was remarkable.

  The present invention has been made in view of such problems, and has been made for the first time by focusing attention on the heat generated by a phosphor that has been neglected in the past. The heat of a wavelength conversion member containing the phosphor It is a main aim of the present invention to provide an LED light-emitting device that can efficiently emit light.

  That is, the light-emitting device according to the present invention includes a base body having a recess opening in the upper end surface, an LED element mounted on the bottom surface of the recess, a translucent member that seals the LED element, and a phosphor. And a wavelength converting member placed on the translucent member, and a translucent heat radiating member placed on the wavelength converting member and covering the opening of the recess. Features.

  If it is such, since the said translucent heat radiating member is mounted on the said wavelength conversion member, it can discharge | release the heat | fever of the said wavelength conversion member efficiently because it is mutually in contact. Further, it is possible to effectively prevent the luminous efficiency and luminance of the phosphor included in the wavelength conversion member from decreasing and thermal deterioration.

  In order to suppress the temporal change of the emission color of the light emitting device according to the present invention, it is preferable that the wavelength conversion member is formed by arranging fluorescent regions that emit light of different colors in parallel.

  When the light emitting device according to the present invention emits white light, the LED element emits near-ultraviolet light in order to suppress uneven color tone, and the phosphor emits red light. The phosphor (hereinafter referred to as red phosphor), the phosphor emitting green light (hereinafter referred to as green phosphor), and the phosphor emitting blue light (hereinafter referred to as blue phosphor) are preferable.

  In the light emitting device according to the present invention, the translucent heat radiating member and the wavelength converting member may be opposite in the vertical direction, and such a light emitting device is also one aspect of the present invention. . That is, the light-emitting device according to the present invention having such an aspect includes a base having a recess opening in the upper end surface, an LED element mounted on the bottom surface of the recess, and a translucent member that seals the LED element. And a light transmissive heat radiating member placed on the light transmissive member, and a wavelength conversion member containing a phosphor placed on the light transmissive heat radiating member and covering the opening of the recess. And.

  According to the present invention having such a configuration, it is possible to satisfactorily suppress changes in phosphor due to heat.

It is a typical longitudinal cross-sectional view of the light-emitting device which concerns on one Embodiment of this invention. It is a typical longitudinal cross-sectional view of the light-emitting device which concerns on other embodiment. It is a typical disassembled perspective view of the light-emitting device concerning the embodiment. It is a typical top view of the wavelength conversion member in other embodiments. It is a typical longitudinal cross-sectional view of the light-emitting device which concerns on other embodiment. It is a typical longitudinal cross-sectional view of the light-emitting device which concerns on other embodiment. It is a typical longitudinal cross-sectional view of the light-emitting device which concerns on other embodiment. It is a typical longitudinal cross-sectional view of the light-emitting device which concerns on other embodiment. It is a typical longitudinal cross-sectional view of the light-emitting device which concerns on other embodiment. It is a typical longitudinal cross-sectional view of the light-emitting device which concerns on other embodiment.

  An embodiment of the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, the light emitting device 1 according to the present embodiment includes a base body 2 having a recess 22 that opens on an upper end surface 21, an LED element 3 mounted on a bottom surface 221 of the recess 22, and an LED element 3. Translucent member 4 to be sealed, wavelength conversion member 5 placed on translucent member 4, and translucent heat radiation placed on wavelength conversion member 5 and covering the opening of recess 22 The member 6 is provided.

Each part will be described in detail.
The base 2 has a recess 22 that opens to the upper end surface 21. For example, a base 2 is formed by molding an insulating material having high thermal conductivity such as alumina or aluminum nitride.

  The base body 2 mounts an LED element 3 to be described later on the bottom surface 221 of the recess 22, and a wiring conductor (not shown) for electrically connecting the LED element 3 to the bottom surface 221. Is formed. This wiring conductor is led to the outer surface of the light emitting device 1 through a wiring layer (not shown) formed inside the base body 2 and connected to the external electric circuit board, whereby the LED element 3 and the external electric circuit board are connected. Are electrically connected.

  A step portion 23 is formed on the side wall of the concave portion 22 of the base 2, and an edge portion of a translucent heat radiating member 6 described later is placed on the upper end surface of the step portion 23.

  The LED element 3 is formed, for example, by laminating a gallium nitride-based compound semiconductor in the order of an n-type layer, a light emitting layer, and a p-type layer on a sapphire substrate. Such an LED element 3 emits blue light or ultraviolet light. .

  The LED element 3 is flip-chip mounted on the bottom surface 221 of the concave portion 22 using solder bumps, gold bumps, or the like with the gallium nitride compound semiconductor facing down (the bottom surface 221 side of the concave portion 22).

  The translucent member 4 is filled in the concave portion 22 and seals the LED element 3. For example, the translucent member 4 is made of a silicone resin having excellent translucency and heat resistance and having a small difference in refractive index from the LED element 3. It is.

  The wavelength conversion member 5 contains a phosphor 51 inside and is placed on the translucent member 4. Examples of such a wavelength conversion member 5 include those in which the phosphor 51 is dispersed in a silicone resin that is excellent in translucency and heat resistance and has a small refractive index difference from the translucent member 4. The concave portion 22 may be filled with an uncured silicone resin in which the phosphor 51 is dispersed, or a sheet processed into a predetermined size may be used. .

  It does not specifically limit as the fluorescent substance 51 which the wavelength conversion member 5 contains, For example, a red fluorescent substance, a green fluorescent substance, a blue fluorescent substance, a yellow fluorescent substance etc. are mentioned.

  The translucent heat radiating member 6 is for releasing the heat of the wavelength conversion member 5 and is placed on the wavelength conversion member 5 to cover the opening of the recess 22. Examples of such translucent heat radiating member 6 include those made of a material having high thermal conductivity and excellent translucency, such as quartz, sapphire, diamond, and aluminum nitride.

  When the translucent heat radiating member 6 is made of quartz, unlike sapphire, the quartz does not have cleavage, so that it can be cut into a truncated cone as shown in FIGS. For this reason, the concave portion 22 of the base 2 can be formed in a truncated cone shape. If the concave portion 22 has a truncated conical shape, the area where the light radiating member 6 or the wavelength converting member 5 and the base 2 are in contact with each other can be increased, so that these heats are more efficiently conducted to the base 2 and released. can do. Further, if the concave portion 22 has a truncated conical shape, even if the dimensional accuracy of the translucent heat radiating member 6 and the wavelength converting member 5 is low, it can be brought into close contact with the inner peripheral surface of the concave portion 22, so that high processing is possible. The adhesiveness between the translucent heat radiating member 6 and the wavelength converting member 5 and the base 2 can be improved without requiring accuracy. Therefore, it becomes possible to improve heat dissipation more effectively.

  Among the light emitting devices 1 according to the present embodiment, the LED element 3 that emits near ultraviolet light is used, and the phosphor 51 that uses a red phosphor, a green phosphor, and a blue phosphor is used. White light is emitted by mixing red light, green light, and blue light emitted by the red, green, and blue phosphors excited by the emitted near-ultraviolet light. The near-ultraviolet light emitted from the LED element 3 does not substantially affect the white color that is the emission color of the light-emitting device 1. For this reason, for example, when the LED element 3 emits blue light and the blue light is configured to be mixed with light emitted from the phosphor 51 included in the wavelength conversion member 5, the light emitting device Although the color unevenness due to the difference in the optical path length is likely to occur on the light emitting surface 1, the LED element 3 emits near-ultraviolet light, and the phosphor 51 is composed of a red phosphor, a green phosphor and a blue phosphor. Some light emitting devices 1 are less likely to cause such uneven color tone.

  The LED element 3 that emits near-ultraviolet light is used, and the mixed light emitted from the light emitting device 1 using the red phosphor, the green phosphor, and the blue phosphor as the phosphor 51 is on the Planck locus. The natural white color is very close to sunlight.

  If it is the light-emitting device 1 which concerns on such embodiment, when the translucent heat radiating member 6 is mounted on the wavelength conversion member 5, it can discharge | release the heat | fever of the wavelength conversion member 5 efficiently. Therefore, it is possible to effectively prevent the luminous efficiency and luminance of the phosphor 51 included in the wavelength conversion member 5 from decreasing and the thermal deterioration.

  The present invention is not limited to the above embodiment.

  For example, the wavelength conversion member 5 does not have to have the phosphors 51 that emit light of different colors uniformly dispersed, and has fluorescent regions that emit light of different colors in parallel. Also good. That is, for example, as shown in FIG. 4, a red fluorescent region R containing a red phosphor, a green fluorescent region G containing a green phosphor, and a blue fluorescent region B containing a blue phosphor are arranged in the horizontal direction. If it is provided, the blue light emitted from the blue phosphor and the green light emitted from the green phosphor are not absorbed by the other phosphors 51, so that the energy conversion efficiency can be increased, and the wavelength In the conversion member 5, when the red fluorescent region R, the green fluorescent region G, and the blue fluorescent region B are laminated in the thickness direction in this order from the lower surface, the red phosphor closer to the LED element 3 deteriorates faster, The light emission color of the light emitting device 1 is likely to change. However, when the fluorescent regions are arranged in parallel in the horizontal direction, the light emission color of the light emitting device 1 changes because it is difficult to make a difference in the deterioration rate of the phosphors 51. Hateful.

  Further, as shown in FIG. 4, particles such as alumina, aluminum nitride, silicon carbide, aluminum, copper, silver, gold, carbon, sapphire, diamond and the like having high thermal conductivity are dispersed on the periphery of the wavelength conversion member 5. The formed heat dissipation area H may be formed. Thus, if the heat dissipation area H is formed at the periphery of the wavelength conversion member 5, the heat of the wavelength conversion member 5 can be released more efficiently.

  Further, in order to block out the ultraviolet light emitted from the LED element 3 without being absorbed by the phosphor 51, the UV cut is applied on the wavelength conversion member 5 or the translucent heat radiating member 6. A filter or the like may be provided.

  Further, the inner wall surface of the recess 22 may function as a reflector by providing a metal thin film having a high reflectance on the inner wall surface of the recess 22 of the base 2.

  Furthermore, the translucent heat radiating member 6 may function as a convex lens, as shown in FIG.

  Further, the LED element 3 may be connected to a wiring conductor provided on the base 2 using wire bonding.

  Further, as shown in FIG. 6, the translucent heat radiating member 6 and the wavelength converting member 5 may have the vertical positions opposite to those of the above embodiment, and the wavelength converting member 5 is the translucent heat radiating member 6. It may be placed on.

  As an embodiment in which the wavelength conversion member 5 is placed on the translucent heat radiating member 6 as described above, a step portion 23 is formed on the side wall of the concave portion 22 of the base 2 as shown in FIG. The edge of the light transmissive heat radiating member 6 may be placed on the upper end surface thereof, and the light transmissive heat radiating member 6 is formed on the upper end surface 21 of the base 2 as shown in FIG. May be placed.

  In the aspect shown in FIG. 8, the translucent heat radiating member 6 is larger than the wavelength converting member 5 in the lateral direction, and further, the base 2 is set larger than the translucent heat radiating member 6. For this reason, the side peripheral surface of the light emitting device 1 has a stepped shape. By setting the size of each member in this manner, the heat generated from the wavelength conversion member 5 can be more efficiently conducted and released to the base body 2 through the translucent heat radiating member 6.

  Moreover, in the said embodiment, although the LED element 3 mounted in the base | substrate 2 is one piece, as shown in FIG.9 and FIG.10, the some LED element 3 may be mounted in the base | substrate 2. FIG. In the embodiment shown in FIGS. 9 and 10, the base 2 includes a substrate 2 a and a frame body 2 b installed on the substrate 2 a, and the upper surface of the substrate 2 a constitutes the bottom surface 221 of the recess 22. In the embodiment shown in FIGS. 9 and 10, in terms of heat dissipation efficiency and wavelength conversion efficiency, the wavelength conversion member 5 is larger than the translucent member 4 in the lateral direction, and more transparent than the wavelength conversion member 5. The light radiating member 6 is set larger.

  In addition, the present invention is not limited to the above-described embodiments, and may be configured by appropriately combining some or all of the various configurations described above without departing from the spirit of the present invention.

  Thus, according to this invention, the LED light-emitting device which suppressed the change of the fluorescent substance by a heat | fever can be obtained.

DESCRIPTION OF SYMBOLS 1 ... Light-emitting device 2 ... Base | substrate 3 ... LED element 4 ... Translucent member 5 ... Wavelength conversion member 6 ... Translucent heat dissipation member

Claims (4)

A base body having a recess opening in the upper end surface;
LED elements mounted on the bottom surface of the recess,
A translucent member for sealing the LED element;
A wavelength conversion member containing a phosphor and placed on the translucent member;
A light-transmitting heat dissipating member placed on the wavelength conversion member and covering the opening of the recess.   The light-emitting device according to claim 1, wherein the wavelength conversion member includes fluorescent regions that emit light of different colors. The LED element emits near ultraviolet light,
The light emitting device according to claim 1, wherein the phosphor is a phosphor that emits red light, a phosphor that emits green light, and a phosphor that emits blue light. A base body having a recess opening in the upper end surface;
LED elements mounted on the bottom surface of the recess,
A translucent member for sealing the LED element;
A light transmissive heat radiating member placed on the light transmissive member;
And a wavelength conversion member containing a phosphor, which is placed on the translucent heat dissipation member and covers the opening of the recess.

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