JP2007043074A - Luminaire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a luminaire capable of reducing the nonuniformity of a luminescent color. <P>SOLUTION: The luminaire comprises a substrate 2; an insulator 4; circuit patterns 5a, 5b arranged on the substrate via the insulator; a plurality of light-emitting devices 6 arranged in a matrix form via the circuit pattern; a reflector 9, that is arranged on the substrate for reflecting light emitted from the plurality of light-emitting devices; a first resin layer 11 for covering the light-emitting devices; and a second resin layer 12, that is formed to have viscosity that is lower than that of the first layer, and is arranged at the upper side of the first resin layer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an illumination device using a light emitting element as a light source.

  As an example of a conventional light emitting diode (LED) illuminating device, a surface mount type device in which a synthetic resin is filled in a case in which an LED chip is disposed and the LED chip is sealed in the case is known ( For example, see Patent Document 1).

As an example of a conventional example in which white light is emitted by this type of LED device, a mixture of blue light emitted by a blue light emitting LED chip and yellow light emitted by a yellow light emitting LED chip (hereinafter referred to as “light emitting”). The first prior art is known). As another conventional example, there is one that mixes blue light of a blue light emitting LED chip and yellow light obtained by exciting a yellow light emitting phosphor by this blue light emission (hereinafter referred to as second prior art). Are known.
JP 2002-43625 A

  However, in the first prior art, since there is a distance between the blue light emitting LED chip and the yellow light emitting LED chip, it is difficult to make the mixed color of blue light and yellow light uniform, and other colors other than white light are used. It is easy to become. Moreover, a space for installing at least two LED chips that respectively emit blue light and yellow light is required, which leads to an increase in the size of equipment on which the chips are mounted.

  In the second prior art, when viewed from the vertical direction with respect to the outer surface of the sealing resin, almost white light is obtained in the central portion where the blue light emitting LED chip is located, but yellow light is distributed in the peripheral portion. And uneven color occurs. For this reason, when viewed obliquely with respect to the outer surface of the sealing resin, it appears that mainly yellow light is emitted. Further, even at the central portion of the outer surface of the sealing resin, the distance between the central portion and the blue light emitting LED chip is closer than the distance between the peripheral portion and the blue light emitting LED chip. The blue light is lost and the white light appears bluish.

  An object of this invention is to provide the illuminating device which can reduce the color nonuniformity of luminescent color.

  The invention of claim 1 includes: a substrate having a plurality of housing portions; a light emitting element disposed in each housing portion; a first resin layer provided in each housing portion and covering the light emitting element; And a second resin layer formed on the upper side of the first resin layer, and having a viscosity lower than that of the resin layer.

  The material of the substrate is glass epoxy resin, aluminum, aluminum nitride, or the like, but a substrate containing aluminum has good heat dissipation and suppresses a temperature increase of the light emitting element, thereby suppressing a decrease in luminous efficiency and element deterioration. Further, the accommodating portion may be formed directly on the substrate, or may be formed on the substrate by another member.

  According to a second aspect of the present invention, there is provided a substrate; an insulator disposed on the substrate; a circuit pattern disposed on the substrate via the insulator; and a plurality of light emitting elements disposed in a matrix via the circuit pattern An element; a reflector disposed on the substrate and reflecting light emitted from the plurality of light emitting elements; a first resin layer covering the light emitting element; and a viscosity lower than that of the first resin layer And a second resin layer formed on the upper side of the first resin layer.

  The insulator is necessary when a metal material is selected as the material of the substrate, but is not necessary in the case of a glass epoxy resin substrate. The circuit pattern is formed of a copper pattern, and, for example, light emitting diodes as a plurality of light emitting elements are electrically connected between the positive electrode and the negative electrode. A plurality of light emitting elements are arranged in a matrix on the substrate to form a surface light source.

  The reflector is formed of a white resin and has a reflecting surface so as to surround the periphery of the light emitting element. Since a circuit pattern is formed on the substrate, a slight gap may be formed between the reflector and the substrate. The emitted light of the light emitting element is reflected by the reflecting surface.

  The first resin layer has a viscosity higher than that of the second resin layer at the time of manufacture, and the one in a muddy state is cured. Therefore, even if a slight gap may be formed between the reflector and the substrate, the amount of resin can be made substantially constant at a predetermined place without flowing into the gap. Then, the amount of light transmitted from each light emitting element arranged on the matrix can be made constant, and the amount of light absorption is made constant in the second resin layer, so that it is converted into visible light without color unevenness. Is.

  The second resin layer is obtained by mixing a phosphor into a silicone resin or the like, and converts it into visible light by light from the light emitting element. The second resin layer has a viscosity lower than that of the first resin layer at the time of manufacture, and is cured in a smooth state. Therefore, it is applied evenly and uniformly on the first resin layer, and there is no change in the thickness of the second resin layer, and the unevenness of the emission color can be reduced.

  Furthermore, you may arrange | position a light control body on a reflector. The light control body is formed of an acrylic resin or the like, and is optically designed for each light emitting element.

  According to a third aspect of the present invention, in the lighting device according to the second aspect, the first resin layer includes a diffusing agent or a reflecting agent.

  According to a fourth aspect of the present invention, in the illumination device according to the third aspect, the second resin layer includes a phosphor, and the particle size of the phosphor is larger than the particle size of the diffusing agent or the reflecting agent. Features.

  According to a fifth aspect of the present invention, in the lighting device according to the fourth aspect, the first resin layer is formed by adding 3 to 5 mass% of a diffusing agent to the resin. When the addition amount of the diffusing agent is zero, that is, when the luminous flux without the addition amount of the diffusing agent is 100%, if the addition amount of the diffusing agent exceeds 5 mass%, the luminous flux decreases, and the addition amount is 3 mass%. If the ratio is less than 1, the effect of reducing color unevenness decreases, so the above range is suitable.

  According to a sixth aspect of the present invention, in the lighting device according to any one of the first to fifth aspects, the refractive index of the second resin layer is between the refractive index of air and the refractive index of the first resin layer. It is characterized by that.

  In the first to fourth aspects of the invention, the first resin layer has a high viscosity at the time of manufacture, and even if a slight gap may be formed between the reflector and the substrate, the first resin layer may flow into the gap. The amount of resin can be made substantially constant at a predetermined location. The amount of light transmitted from each light emitting element arranged on the matrix can be made constant, and the amount of light absorption is constant in the second resin layer, so that it can be converted into visible light without color unevenness. It is. Furthermore, the second resin layer has a low viscosity at the time of manufacture, and is evenly and evenly applied on the first resin layer. The thickness of the second resin layer is not changed, and the overall emission color is not changed. Color unevenness can be reduced.

  In the invention of claim 5, since the first resin layer adds 3 to 5% by mass of the diffusing agent to the resin, the light flux in the case where the addition amount of the diffusing agent is zero, that is, the addition amount of the diffusing agent is not present. When the addition amount of the diffusing agent exceeds 5% by mass, the luminous flux decreases. When the addition amount is less than 3% by mass, the effect of reducing color unevenness decreases, so the above range is preferable. .

  In the invention of claim 6, since the refractive index of the second resin layer is between the refractive index of air and the refractive index of the first resin layer, the light emitted from the light emitting element is relatively refracted. When entering the second resin layer having a low refractive index from the first resin layer having a high rate, the amount of light reflected at the interface can be reduced, and the efficiency of extracting light from the lighting device is improved.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a lighting device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1, and FIG. As shown in the figure, the lighting device 1 has a plurality of light emitting devices 3, 3... Arranged on a substrate 2 in a matrix of, for example, 3 rows and 3 columns, and are integrally connected. The substrate 2 is made of a flat plate made of aluminum (Al), Ni, glass epoxy or the like having heat dissipation and rigidity, and a lead frame 5 is disposed on the substrate 2 via an electrical insulator 4.

  As shown in FIG. 3, the lead frame 5 has cathode and anode circuit patterns (wiring patterns) 5a and 5b formed of an alloy of Cu and Ni, Au, or the like for each LED device 3, and this lead frame. 5, a blue light emitting LED chip 6 as a light emitting element is mounted for each light emitting device 3. Each blue light emitting LED chip 6 is made of, for example, a gallium nitride (GaN) semiconductor that emits blue light. Each blue light emitting LED chip 6 has its bottom electrode placed on one of the circuit patterns 5a and 5b to be electrically connected, while its top electrode is connected to the other of the circuit patterns 5a and 5b by a bonding wire 7. Yes.

  Then, on the substrate 2, a concave portion 8 is formed as a housing portion. That is, a frustoconical concave portion that surrounds each blue light emitting LED chip 6 with a predetermined interval and constitutes a reflecting surface that gradually expands toward the opposite side of the substrate 2 (upward in FIGS. 2 and 3). A reflector 9 in which 8 is formed concentrically is formed for each LED device 3, and these are integrally formed. The reflector 9 is made of a synthetic resin such as PBT (polybutylene terephthalate), PPA (polyphthalamide), PC (polycarbonate), etc., and each recess 8 has an opening 8a that opens to the outside.

  Each recess 8 is filled with a thermosetting transparent resin such as translucent silicone rubber or epoxy resin as a sealing resin 10. The sealing resin 10 includes a diffusion layer 11 as a first resin layer on the blue light emitting LED chip 6 side and a yellow light emitting phosphor layer 12 as a second resin layer on the concave opening 8a side. Has been.

  The refractive index of the second resin layer is set to be between the refractive index of air and the refractive index of the first resin layer. Then, when the light emitted from the light emitting element enters the second resin layer having a relatively low refractive index from the first resin layer having a relatively high refractive index, the amount of light reflected at the interface can be reduced, and illumination can be achieved. The efficiency of extracting light from the device can be improved.

The diffusion layer 11 is a blue light emitting sealing resin obtained by adding 3 to 5 mass% (mass%) of a diffusing agent such as alumina (Al ₂ O ₃ ), Ti, Ca, Si, Al, or Y in the recess 8. It is formed by injecting to a position higher than the LED chip 6 and thermosetting, and the boundary surface 11a with the phosphor layer 12 is formed in a curved surface recessed to the blue light emitting LED chip 6 side (lower surface side in FIG. 3). Yes. The curved boundary surface 11a is preferably 1 μm to 5 μm, for example, between the upper end and the lower end of the curve.

  Moreover, since the addition amount of the diffusing agent added to the sealing resin 10 of the diffusion layer 11 is 3 to 5% by mass, it is possible to reduce the color unevenness of white light without reducing the luminous flux. Table 1 below shows changes in luminous flux depending on the amount of diffusing agent added. In addition, when the addition amount of the diffusing agent is zero, that is, when the addition amount of the diffusing agent is 100%, when the addition amount of the diffusing agent exceeds 5% by mass, the light flux is decreased and the addition amount is 3 When the content was less than mass%, the effect of reducing color unevenness decreased.

  The yellow light-emitting phosphor layer 12 is sealed by adding the required mass% of a yellow light-emitting phosphor that receives blue light from the LED chip 6 and fluoresces yellow after the thermosetting formation of the diffusion layer 11. It is configured by injecting resin and thermosetting.

  Next, the effect | action of this illuminating device 1 is demonstrated. First, when a predetermined DC voltage is applied between the cathode-side and anode-side circuit patterns 5a and 5b from the outside, each blue light-emitting LED chip 6 emits blue light. This blue light emission is diffused in multiple directions by the diffusion layer 11 and then enters the yellow light emitting phosphor layer 12, where the yellow phosphor is excited from multiple directions to emit yellow light and is mixed with this yellow color. It becomes white light and is radiated to the outside from each recess opening 8a.

  The diffusion layer 11 has a high viscosity at the time of manufacture, and even if a slight gap is formed between the reflector 9 and the substrate 2, the diffusion layer 11 does not flow into the gap, and the amount of resin is reduced in the recess 8. It can be made almost constant. The amount of light transmitted from each light emitting element arranged on the matrix can be made constant, and the amount of light absorption becomes constant in the yellow light emitting phosphor layer 12, so that it is converted into visible light without color unevenness. Is. Further, the yellow light-emitting phosphor layer 12 has a low viscosity at the time of manufacture, and is evenly and evenly coated on the diffusion layer 11, and the thickness of the yellow light-emitting phosphor layer 12 does not change, and the emission color as a whole. Color unevenness can be reduced.

  Therefore, according to this LED illumination device 1, minute light emission of the blue light emitting LED chip 6 is diffused in multiple directions by the diffusion layer 11, and the yellow phosphor of the phosphor layer 12 is excited from multiple directions to emit yellow light. In addition, since the yellow light and the blue light are mixed to emit white light, the color unevenness of the white light can be reduced.

  If the addition ratio of the diffusing agent in the diffusion layer 11 is more than 5% by mass, the amount of light emitted from the blue light emitting LED chip 6 and the like is absorbed by the substrate 2 made of Ni or the like. The luminous flux of white light radiated on the screen is reduced.

  In view of this, the light receiving surface of the substrate 2 may be coated with a reflective material such as a white paint to form the reflective surface, thereby preventing or suppressing a decrease in luminous flux.

The top view of the LED lighting apparatus which concerns on embodiment which concerns on this invention. Similarly, the II-II sectional view taken on the line of FIG. Similarly, the III part enlarged view of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 2 ... Board | substrate, 4 ... Insulator, 5a, 5b ... Circuit pattern, 6 ... Light emitting element, 9 ... Reflector, 11 ... Diffusion layer, 12 ... Phosphor layer.

Claims (6)

A substrate having a plurality of receiving portions;
A light emitting device disposed in each housing portion;
A first resin layer provided in each housing portion and covering the light emitting element;
A second resin layer formed at a lower viscosity than that of the first resin layer and disposed on the upper side of the first resin layer;
An illumination device comprising: A substrate;
An insulator disposed on the substrate;
A circuit pattern disposed on the substrate via an insulator;
A plurality of light emitting elements arranged in a matrix through a circuit pattern;
A reflector disposed on the substrate and reflecting light emitted from the plurality of light emitting elements;
A first resin layer covering the light emitting element;
A second resin layer formed at a lower viscosity than that of the first resin layer and disposed on the upper side of the first resin layer;
An illumination device comprising:   The lighting device according to claim 2, wherein the first resin layer contains a diffusing agent or a reflecting agent.   The lighting device according to claim 3, wherein the second resin layer contains a phosphor, and the particle size of the phosphor is larger than the particle size of the diffusing material or the reflecting material.   The lighting device according to claim 4, wherein the first resin layer is obtained by adding 3 to 5 mass% of a diffusing agent to the resin.   6. The lighting device according to claim 1, wherein the refractive index of the second resin layer is between the refractive index of air and the refractive index of the first resin layer.

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