JP2007294890A - Light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device which can establish optional luminescent chromaticity without reducing light extraction efficiency. <P>SOLUTION: The light emitting device includes a substrate 14, a white insulating layer 15 formed thereon; a circuit pattern 16 which is formed on the insulating layer and has a light emitting element connection, a light emitting element 13 which is arranged on the insulating layer and is electrically connected with the light emitting element connection of the circuit pattern layer; a phosphor-containing resin layer 27 which includes a yellow phosphor that is excited by a blue light radiated from the light emitting element to emit a yellow light or an orange light, and is arranged to cover the light emitting element; and a sheet-like phosphor layer 30 which includes a red phosphor that is excited by a blue light radiated from the light emitting element to emit a red light, and is arranged on the phosphor-containing resin layer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a light emitting device such as a light emitting diode lamp.

Conventionally, as a typical method for realizing white light emission by a light emitting diode (LED), a combination of a blue light emitting LED chip and a yellow or orange light emitting phosphor has been widely put into practical use. And this type of LED lamp has a structure in which a transparent resin mixed with a phosphor is poured into a cup-shaped frame equipped with an LED chip and solidified to form a resin layer containing the phosphor. Yes (see, for example, Patent Document 1). In such an LED lamp, the use of a red light emitting phosphor in addition to a yellow or orange light emitting phosphor is expected to improve not only the color rendering property but also the light emission efficiency. In addition, in order to improve color rendering properties, red light emitting phosphors such as nitrides and sulfides have been actively developed.
JP 2001-148516 A

  However, since this type of light emitting device is prepared by mixing one or more kinds of phosphors and mixing them with a transparent resin in accordance with desired light emission characteristics such as high color rendering properties, color temperature, and light emission luminance, the desired chromaticity is achieved. Difficult to adjust. In addition, it is necessary to consider that the phosphor emitting red light has a characteristic of absorbing yellow light. From this point, it is difficult to adjust optical characteristics such as luminous intensity and chromaticity. That is, the efficiency of extracting light from the light emitting device is lowered, and it is difficult to obtain desired chromaticity.

  An object of this invention is to provide the light-emitting device which can obtain desired light emission chromaticity, without reducing light extraction efficiency.

  The invention of claim 1 includes: a substrate; a white insulating layer provided on the substrate; a circuit pattern layer having a light emitting element connecting portion provided on the insulating layer; and a circuit disposed on the insulating layer. A light-emitting element electrically connected to the light-emitting element connection portion of the pattern layer; and a yellow phosphor that emits yellow light or orange light when excited by blue light emitted from the light-emitting element. A sheet containing a phosphor-containing resin layer disposed so as to cover; a red phosphor that emits red light when excited by blue light emitted from a light-emitting element; and disposed on the phosphor-containing resin layer And a phosphor layer.

  For example, the substrate may be a substrate having a wiring portion such as a circuit pattern layer or a lead terminal, or may be configured to include a substrate and a reflector that is provided on the substrate and forms a recess that opens to the outside. is there. In addition, you may make it produce a board | substrate by forming a recessed part directly on a board | substrate, without using a reflector. In addition, since the substrate is provided with a white insulating layer, a metal material or a glass epoxy resin material excellent in heat dissipation can be used. Note that a white resin can be used for the white insulating layer.

  A light emitting element that emits blue light excites a phosphor with emitted blue light to emit visible light. Examples of the light emitting element that emits blue light used in the present invention include a blue light emitting type LED chip, but are not limited thereto.

  The phosphor-containing resin layer is excited by the blue light emitted from the light emitting element and emits yellow light or orange light (hereinafter referred to as yellow light) to emit yellow or orange light emitting phosphor (hereinafter referred to as yellow phosphor). ) Is mixed and dispersed in a resin, and is applied and filled so as to cover the light emitting element. As the resin, for example, an epoxy resin or a silicone resin can be applied.

  The sheet-like phosphor layer retains a red phosphor that emits red light when excited by blue light emitted from the light emitting element. The red phosphor is mixed and dispersed in a resin such as a silicone resin. The red phosphor-containing resin is formed into a sheet shape. The sheet-like phosphor layer preferably has a thickness of about 0.5 to 1.0 mm, and is disposed on the phosphor-containing resin layer. When the thickness of the sheet-like phosphor layer is less than 0.5 mm, a sufficient amount of the phosphor cannot be contained, and when it exceeds 1.0 mm, the light transmittance is lowered and it is difficult to obtain a desired light amount. .

  The invention of claim 2 includes: a substrate; a white insulating layer provided on the substrate; a circuit pattern layer having a light emitting element connecting portion provided on the insulating layer; on the insulating layer and the circuit pattern layer of the substrate And a receiving portion that opens on the insulating layer of the substrate and the light emitting element connecting portion of the circuit pattern layer corresponding to the position where the light emitting element is provided, and the light emitting element connecting portion of the circuit pattern layer is provided in the peripheral area in the receiving portion. A reflector configured to be positioned; disposed on the insulating layer in a central region of the bottom surface in the housing portion and electrically connected to the light emitting element connection portion of the circuit pattern layer located in the peripheral region in the housing portion A light-emitting element; a phosphor-containing resin layer that contains a yellow-based phosphor that emits yellow light or orange light when excited by blue light emitted from the light-emitting element, and is disposed so as to cover the light-emitting element; Emitted from the element Is excited by the blue light contains a red phosphor emitting red light, a phosphor-containing resin layer disposed on a sheet-shaped phosphor layer; characterized in that it comprises a.

  According to a third aspect of the present invention, in the light emitting device according to the second aspect, the ratio of the surface area of the light emitting element connection portion to the surface area of the bottom surface in the housing portion is 50% or less. If the ratio of the surface area of the light emitting element connection portion to the surface area of the bottom surface in the housing portion is greater than 50%, the efficiency of reflecting the light traveling from the light emitting element toward the bottom surface side of the housing portion on the white bottom surface is reduced. It is difficult to sufficiently improve the light extraction efficiency.

  According to a fourth aspect of the present invention, in the light emitting device according to any one of the first to third aspects, the light emitting element is fixed on the insulating layer by a transparent adhesive. And a transparent epoxy resin, a silicone resin, etc. can be used for a transparent adhesive agent.

  According to a fifth aspect of the present invention, in the light emitting device according to any one of the first to fourth aspects, the reflectance of the surface of the insulating layer is 85% or more in a wavelength region of 400 to 740 nm. When the reflectance of the surface of the insulating layer is less than 85% in the wavelength range of 400 to 740 nm, the efficiency of reflecting light from the light emitting element toward the substrate by the insulating layer is low, and the light extraction efficiency of the light emitting element is sufficiently improved. I can't get it. In addition, the said reflectance is a total light reflectance, for example.

  According to a sixth aspect of the present invention, in the light emitting device according to any one of the first to fifth aspects, the insulating layer has a thickness in the range of 30 μm to 90 μm. When the thickness of the insulating layer is less than 30 μm, light is transmitted through the insulating layer, the reflectance is lowered, and the insulating performance is lowered. On the other hand, when the thickness of the insulating layer is greater than 90 μm, the thermal resistance of the insulating layer is increased, heat dissipation is reduced, and the life of the light emitting element is shortened. The range is preferably 40 μm to 60 μm.

  According to the light emitting device of claim 1, since the blue light from the light emitting element is reflected by the white insulating layer, the sheet-like phosphor layer further containing the red phosphor without reducing the light extraction efficiency. Thus, a desired emission chromaticity can be obtained.

  According to the light emitting device of claim 2, the white insulating layer and the circuit pattern layer are provided on the substrate, and the light emitting element is formed on the insulating layer in the central region within the reflector housing provided on the insulating layer and the circuit pattern. And the electrical connection to the light emitting element connecting portion of the circuit pattern layer located in the peripheral area in the accommodating portion increases the proportion of the white insulating layer, and the light from the light emitting element toward the substrate side is white. The insulating layer can efficiently reflect the light, and the light extraction efficiency of the light emitting element can be improved.

  According to the light emitting device of the third aspect, in addition to the effect of the light emitting device of the second aspect, the ratio of the surface area of the light emitting element connecting portion to the surface area of the bottom surface in the housing portion is 50% or less, so The take-out efficiency can be further improved.

  According to the light emitting device of the fourth aspect, in addition to the effects of the light emitting device according to the first to third aspects, the light emitting element is fixed on the insulating layer by the transparent adhesive. Even in the case of a light emitting element that emits light also from the back side, the light emitted from the back side of the light emitting element can be transmitted through the transparent adhesive and efficiently reflected by the white insulating layer. The light extraction efficiency can be improved.

  According to the light emitting device according to claim 5, in addition to the effect of the light emitting device according to any one of claims 1 to 4, the reflectance of the surface of the insulating layer is 85% or more in the wavelength range of 400 to 740 nm. Light from the light emitting element toward the substrate can be efficiently reflected by the white insulating layer, and the light extraction efficiency of the light emitting element can be improved.

  According to the light emitting device according to claim 6, in addition to the effect of the light emitting device according to any one of claims 1 to 5, in order to make the thickness of the insulating layer in the range from 30 μm to 90 μm, The heat dissipation can be improved.

  Hereinafter, a light-emitting device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an enlarged sectional view of a part of a light emitting device according to an embodiment of the present invention, FIG. 2 is an enlarged front view of the same light emitting device, and FIG. 3 is a light emitting element of the light emitting device. 4 is a front view of the above light emitting device, and FIG. 5 is a diagram showing the chromaticity of light emission of the light emitting devices obtained in Examples 1 to 3 on the CIE chromaticity diagram. is there.

  In the figure, a light emitting device 11 includes a light emitting module 12, and the light emitting module 12 is detachably attached to a light emitting device main body (not shown) such as a fixture main body of a lighting fixture. In the light emitting module 12, light emitting diode elements (light emitting diode chips) 13 which are chip-like solid light emitting elements as a plurality of light emitting elements are arranged in a matrix.

  For example, a gallium nitride (GaN) -based semiconductor that emits blue light having an emission peak of 450 to 460 nm is laminated on a sapphire substrate, and the surface of the light-emitting diode element 13 includes a cathode side and an anode for wire bonding. A so-called double wire type in which side electrodes are provided is used. This type of light-emitting diode element 13 has a characteristic that the light transmitted to the back side through the sapphire substrate is about twice as much as the light transmitted to the front side.

  The light emitting module 12 includes a flat substrate 14 made of aluminum (Al), nickel (Ni), glass epoxy resin or the like having heat dissipation and rigidity, a white insulating layer 15 formed on one surface of the substrate 14, and the insulating layer. The circuit pattern layer 16 formed on the circuit board 15, the insulating layer 15, and the reflector 17 formed integrally on the circuit pattern layer 16 are provided.

  The insulating layer 15 is made of an insulating white resin and is formed so as to cover the entire surface of the substrate 14. The reflectance of the surface of the insulating layer 15 is preferably 85% or more in the wavelength range of 400 to 740 nm. If the reflectance is smaller than 85%, the efficiency of reflecting the light from the light emitting diode element 13 toward the substrate 14 on the insulating layer 15 is improved. Therefore, the light extraction efficiency of the light emitting diode element 13 cannot be sufficiently improved. Here, the graph which shows the total light reflectance of the white resin material used for a light-emitting device is shown in FIG. The horizontal axis of the graph is the wavelength (nm), the vertical axis is the total light reflectance (%), the solid line is the total light reflectance of the white resin material, and the dotted line is the total light reflectance of silver as a comparative example. Yes. In the case of silver, it has a total light reflectance of 85% or more in the entire wavelength range of 400 to 740 nm. On the other hand, in the case of a white resin material, the total light reflectance is 35% at a wavelength of 400 nm, and the wavelength of 480 to 740 nm is 85% or more. However, since the average total light reflectance is 85% or more in the entire wavelength range of 400 to 740 nm, the light extraction efficiency can be sufficiently improved.

  In addition, since the insulating layer 15 is provided on almost the entire surface of the substrate 14, productivity is improved as compared with the case where the insulating layer 15 is accurately provided only at the required position on the substrate 14, that is, the position of the accommodating portion 19 of the reflector 17. it can. The thickness of the insulating layer 15 is preferably in the range of 30 μm to 90 μm, and heat dissipation can be improved while ensuring the reflectance. Here, the thickness of the insulating layer 15 will be described taking the thicknesses of 30 μm, 90 μm, and 120 μm as examples. FIG. 7 shows the reflectance at a wavelength of 460 nm, the reflectance at a wavelength of 550 nm, and the thermal resistance (° C./W) when the insulating layer 15 has a thickness of 30 μm, 90 μm, and 120 μm. The thinner the insulating layer 15, the lower the reflectivity. On the other hand, the thicker the insulating layer 15, the higher the thermal resistance. The light emitting diode element 13 has a life of 40,000 hours when the junction temperature is used at 100 ° C. Therefore, to increase the life of the light emitting diode element 13, the junction temperature should be kept below 100 ° C. It is preferable to do this.

  When the number of watts per chip of the light emitting diode element 13 is 0.06 W, as shown in FIG. 8, the temperature rise when the power is turned on when 0.06 W of power is applied causes the thickness of the insulating layer 15 to be thin. Since the thermal resistance is lower, the temperature rise is lower. On the other hand, the thicker the insulating layer 15, the higher the thermal resistance. For example, in a sealed luminaire using a light emitting diode element capable of obtaining a light flux of 5000 lm as a light source, the ambient temperature in the fixture is 60 ° C to 70 ° C. Since the value obtained by adding the above-mentioned temperature rise to this temperature is the junction temperature, the junction temperature exceeds 100 ° C. when the thickness of the insulating layer 15 is 120 μm. Therefore, in order to use the junction temperature below 100 ° C. The thickness of the insulating layer 15 needs to be 90 μm or less. On the other hand, when the thickness of the insulating layer 15 is reduced, the light is transmitted through the insulating layer 15, so that the reflectance is lowered. As shown in FIG. 9, the relationship between the thickness of the insulating layer 15 and the total luminous flux (lm) per chip of the light-emitting diode element 13, the reduction of the total luminous flux is the maximum value when the thickness of the insulating layer 15 is 120 μm. On the other hand, the thickness of the insulating layer 15 is considered to be 30 μm or more because it is desired to suppress it to about 10%. Therefore, the thickness of the insulating layer 15 is preferably in the range of 30 μm to 90 μm, and heat dissipation can be improved while ensuring the reflectance.

  The circuit pattern layer 16 is formed with cathode-side and anode-side circuit patterns (wiring patterns) 16a and 16b for each light-emitting diode element 13 placement position, which is a light-emitting element placement position. End portions of 16b are formed as connection portions 16a1 and 16b1 as light emitting element connection portions for electrically connecting the light emitting diode elements 13. The circuit pattern layer 16 is formed, for example, by forming a Cu layer on the insulating layer 15 of the substrate 14 and removing a portion of the Cu layer other than the circuit pattern layer 16 and then forming a Ni layer and an Ag layer on the Cu layer by electroplating. Formed and configured.

  The reflector 17 is integrally formed by pouring a resin such as PBT (polybutylene terephthalate), PPA (polyphthalamide), or PC (polycarbonate) into one surface of the substrate 14. A plurality of accommodating portions 19 that are recesses for accommodating the respective light emitting diode elements 13 are formed for each arrangement position of the respective light emitting diode elements 13. Each accommodating portion 19 is formed in a truncated cone shape that gradually expands toward the opposite side with respect to the substrate 14. A lens holder portion 20 for fixing a lens (not shown) is formed around the housing portion 19 concentrically.

  The white insulating layer 15 faces most of the bottom surface 19a in each housing portion 19 including the central region of the bottom surface 19a of the housing portion 19, and the circuit patterns 16a and 16b are connected to the peripheral area of the bottom portion of the housing portion 19 The parts 16a1 and 16b1 are located. The connecting portions 16a1 and 16b1 have a minimum size within a range that allows wire bonding, and the connecting portions 16a1 and 16b1 are accommodated away from the light emitting diode element 13 disposed in the central region in the accommodating portion 19. Located near the periphery of part 19. The ratio of the surface area of the connecting portions 16a1 and 16b1 to the surface area of the bottom surface 19a in the housing portion 19 is 50% or less. If the surface area is larger than 50%, light directed from the light emitting diode element 13 toward the bottom surface 19a of the housing portion 19 is emitted. The efficiency of reflection by the white insulating layer 15 becomes low, and the light extraction efficiency of the light emitting diode element 13 cannot be sufficiently improved.

  Each light-emitting diode element 13 is fixed on the insulating layer 15 in the center region of the bottom surface 19a of the accommodating portion 19 using a transparent adhesive 21 such as a transparent epoxy resin or silicone resin. In the fixing operation, the transparent adhesive 21 is applied on the insulating layer 15 in the central region of the bottom surface 19a of the accommodating portion 19, and the light emitting diode element 13 is pressed against the transparent adhesive 21. At this time, the transparent adhesive 21 protrudes around the light emitting diode element 13 from between the light emitting diode element 13 and the insulating layer 15, and a protruding portion 22 is formed around the light emitting diode element 13. The protruding portion 22 is also applied to the lower side of the side surface of the light emitting diode element 13, and the surface of the protruding portion 22 is concave due to contraction when the transparent adhesive 21 is solidified.

  The electrodes on the surface of the light emitting diode element 13 and the connection portions 16a1 and 16b1 of the circuit patterns 16a and 16b are electrically connected by bonding wires 23 by wire bonding. Each accommodating portion 19 is formed with a covering layer 25 that covers the light emitting diode element 13. The covering layer 25 is formed in two layers: a diffusion layer 26 that covers the light emitting diode element 13 and a phosphor-containing resin layer 27 that is disposed on the opening side of the housing portion 19 above the diffusion layer 26. Yes.

The diffusion layer 26 is blended with a diffusing agent such as alumina (Al ₂ O ₃ ), TiO ₂ , BaSO ₄ , SiO ₂ , Y ₂ O _{3 in a} thermosetting transparent resin such as a translucent silicone resin or epoxy resin. Thus, the resin blended with the diffusing agent is filled up to a position higher than the light emitting diode element 13 in the accommodating portion 19 and is thermally cured. A joining surface (boundary surface) 28 between the diffusion layer 26 and the phosphor-containing resin layer 27 is formed as a curved surface that is concave toward the light emitting diode element 13 side (the lower surface side in FIG. 1).

Phosphor-containing resin layer 27 is mainly composed of a thermosetting transparent resin such as translucent silicone resin or epoxy resin, mainly composed of a yellow phosphor that receives blue light from light emitting diode element 13 and emits fluorescent light in yellow. In this case, after the thermosetting of the diffusion layer 26, the resin containing the phosphor is filled in the accommodating portion 19 and is thermoset. The phosphor-containing resin layer 27 contains a yellow phosphor that is excited by the blue light emitted from the light-emitting diode element 13 and emits yellow light or orange light, and is disposed so as to cover the light-emitting element. Examples of yellow phosphors include YAG phosphors such as RE ₃ (Al, Ga) ₅ O ₁₂ : Ce phosphor (RE represents at least one selected from Y, Gd, and La), AE ₂ SiO, and the like. ₄ : Selected from silicate phosphors such as Eu phosphors (AE represents an alkaline earth element such as Sr, Ba, Ca). As such a yellow phosphor, two types of phosphors having different dominant wavelengths can be used.

  The opening of the housing 19 contains a red phosphor that is excited by the blue light emitted from the light emitting diode element 13 and emits red light, and is arranged on the phosphor-containing resin layer 27. The red phosphor sheet 30 as the body layer 30 is disposed so that the upper end surface thereof is substantially flush with the opening. The red phosphor sheet 30 is formed by adding a red phosphor to a transparent resin such as a silicone resin and mixing it, then forming it into a sheet having a thickness of 0.5 to 1.0 mm by a doctor blade method or the like. It is formed by curing the resin by heating for a period of time. In the formation of the red phosphor sheet 30, when bubbles are mixed when the transparent resin and the phosphor are mixed, it is preferable to remove the bubbles by vacuum degassing.

The red phosphor contained in the red phosphor sheet 30 is excited by blue light emitted from the light emitting diode element 13 and emits red light having a dominant wavelength of 590 to 640 nm. As the red phosphor, an oxysulfide phosphor such as a La ₂ O ₂ S: Eu phosphor is used. Furthermore, instead of the phosphors as described above, nitride phosphors (for example, AE ₂ Si ₅ N ₈ : Eu) that can obtain various emission colors depending on the composition, oxynitride phosphors (for example, Y ₂ Si ₃ O ₃ N ₄ : Ce), a sialon-based phosphor (for example, AE _x (Si, Al) ₁₂ (N, O) ₁₆ : Eu), or the like may be applied.

  Further, the lighting device can be configured by combining the light emitting device 11 and the lens. Next, the operation of the light emitting device 11 will be described. When a predetermined DC voltage is applied between the cathode-side and anode-side circuit patterns 16a and 16b from the outside, each light-emitting diode element 13 emits blue light. This blue light emission is diffused in multiple directions by the diffusion layer 26 and then enters the phosphor-containing resin layer 27, where the yellow phosphor is excited from multiple directions to emit yellow light. Then, the blue light from the light emitting diode element 13 and the yellow light from the yellow phosphor are mixed. Further, part of the blue light emitted from the light emitting diode element 13 is converted into red light, which is longer wavelength light, by the red phosphor contained in the red phosphor sheet 30. Then, blue light emitted from the light emitting diode element 13 and white light having a color based on the emission colors of the yellow phosphor and the red phosphor are emitted from the light emitting device 11.

  At this time, by changing the dominant wavelength of light emitted from the red phosphor sheet 30, the chromaticity of light emission can be changed, and desired light emission characteristics such as color temperature, light emission luminance, and color rendering can be easily realized. . That is, by adjusting the main wavelength and the blending amount of the red phosphor contained in the red phosphor sheet 30, the light emitting device 11 whose emission chromaticity is located on the locus of black body radiation and has high color rendering properties can be obtained. It is also possible to obtain a light emitting device 11 that achieves a desired color temperature and is superior in color rendering performance to light emission efficiency. In addition, red phosphor sheets 30 containing various red phosphors having different main wavelengths in various proportions are prepared, and the chromaticity of light emission is adjusted by appropriately changing the red phosphor sheets 30. Is also possible.

  Therefore, in this light emitting device 11, minute light emission of the light emitting diode element 13 is diffused in multiple directions by the diffusion layer 26, and the yellow phosphor of the phosphor-containing resin layer 27 is excited from multiple directions to emit yellow light, and Since the yellow light and the blue light are mixed to emit white light, the color of the white light can be reduced. Further, since the light traveling from the light emitting diode element 13 toward the substrate 14 can be efficiently reflected by the white insulating layer 15, the light extraction efficiency of the light emitting diode element 13 can be improved. In particular, the ratio of the surface area of the connecting portions 16a1 and 16b1 to the surface area of the bottom surface 19a in the accommodating portion 19 is 50% or less, and the reflectance of the surface of the insulating layer 15 is 85% or more in the wavelength range of 400 to 740 nm. Thus, the light traveling from the light emitting diode element 13 toward the substrate 14 can be efficiently reflected by the white insulating layer 15, and the light extraction efficiency of the light emitting diode element 13 can be further improved.

  In addition, since the light emitting diode element 13 is fixed on the white insulating layer 15 in the center region of the bottom surface 19a in the housing portion 19 by the transparent adhesive 21, the light emitted from the back side of the light emitting diode element 13 is transparently bonded. The light can be transmitted through the agent 21 and can be efficiently reflected by the white insulating layer 15, and the light extraction efficiency of the light emitting diode element 13 can be improved. In addition, since light from the light emitting diode element 13 is emitted from the protruding portion 22 of the transparent adhesive 21 protruding around the light emitting diode element 13, the protruding portion 22 in the vicinity of the light emitting diode element 13 is also illuminated from the front. The light emission area can be increased and the light extraction efficiency of the light emitting diode element 13 can be improved.

  Furthermore, since the surface of the protruding portion 22 of the transparent adhesive 21 is concave, light emitted from the surface of the protruding portion 22 spreads in multiple directions, and the light extraction efficiency of the light emitting diode element 13 can be improved. Further, since the connecting portions 16a1 and 16b1 are located near the periphery of the housing portion 19 that is separated from the light emitting diode element 13 in the central region in the housing portion 19, the light traveling from the light emitting diode element 13 to the white insulating layer 15 and The light that passes through the transparent adhesive 21 and is reflected by the white insulating layer 15 can be prevented from being reflected by the connection portions 16a1 and 16b1 having low reflectivity, and the light extraction efficiency of the light-emitting diode element 13 can be improved.

  Next, an LED lamp (corresponding to the light emitting device of the first embodiment) showing the second embodiment according to the present invention will be described. In the present embodiment, a plurality of light emitting elements are arranged in a matrix in one recess. Reference numeral 1 in FIGS. 10 and 11 denotes an LED lamp. The LED lamp 1 includes an LED chip 2 as a plurality of light emitting elements, a circuit pattern 3, a substrate 4, a reflective layer 5 as a white insulating layer, a reflector 8 as a reflector, and a phosphor layer. A phosphor-containing resin layer 9, a sheet-like phosphor layer 10, a translucent adhesive layer 21, and a light diffusion member 22 are provided to form a light emitting device. The substrate 4 and the reflector 8 cooperate to form the recess 7.

  The substrate 4 is made of a flat plate made of an insulating material such as a synthetic resin, and has a predetermined shape such as a rectangular shape in order to obtain a light emitting area required for the LED lamp 1. The reflective layer 5 has such a size that a predetermined number of LED chips 2 can be disposed, and is attached to the entire surface of the substrate 4, for example. The reflective layer 5 is formed of a white insulating material having a reflectance of 85% or more in a wavelength region of 400 nm to 740 nm. The white insulating material forming the reflective layer 5 is formed by impregnating a sheet base material with a thermosetting resin mixed with white powder such as aluminum oxide. The reflective layer 5 is bonded to one surface as the surface of the substrate 4 by its own adhesiveness.

  The circuit pattern 3 is bonded to the surface of the reflective layer 5 opposite to the surface to which the substrate 4 is bonded as an energization element to each LED chip 2. For example, in order to connect the LED chips 2 in series, the circuit pattern 3 is formed in two rows in the longitudinal direction of the substrate 4 and the reflective layer 5 at predetermined intervals as shown in FIG. An end side circuit pattern 3a located on one end side of one circuit pattern 3 row is integrally formed with a power feeding pattern portion 3c. Similarly, an end side located on one end side of the other circuit pattern 3 row side. The circuit pattern 3a is integrally formed with a power feeding pattern portion 3d. The power feeding pattern portions 3 c and 3 d are provided side by side at one end in the longitudinal direction of the reflective layer 5 and are separated from each other and insulated by the reflective layer 5. Electric wires (not shown) reaching the power supply are individually connected to the power supply pattern portions 3c and 3d by soldering or the like.

  Each LED chip 2 is made of a double-wire type LED chip using, for example, a nitride semiconductor, does not have a reflective film, and can emit light both in the thickness direction. Each LED chip 2 is disposed between the circuit patterns 3 adjacent to each other in the longitudinal direction of the substrate 4, and is bonded to the same surface of the white reflective layer 5 by a translucent adhesive layer 21. By this adhesion, the circuit pattern 3 and the LED chip 2 are arranged in a straight line on the same surface of the reflective layer 5, so that the side surfaces 2 a and 2 b of the LED chip 2 positioned in this arrangement direction are close to the circuit pattern 3. It is provided so as to face each other. The thickness of the translucent adhesive layer 21 is 5 μm or less. For the translucent adhesive layer 21, for example, a translucent adhesive having a thickness of 5 μm or less and a light transmittance of 70% or more, such as a silicone resin adhesive, can be suitably used.

  The electrode of each LED chip 2 and the circuit pattern 3 arranged close to both sides of the LED chip 2 are connected by a bonding wire 6 provided by wire bonding. Further, the end side circuit patterns located on the other end side of the two rows of circuit patterns 3 rows are also connected by wire bonding. Therefore, in this embodiment, each LED chip 2 is connected in series.

  The reflector 8 is not individually provided for each one or several LED chips 2, but is a single one that surrounds all the LED chips 2 on the reflective layer 5, and has a frame, for example, shown in FIG. It is formed with a rectangular frame. The reflector 8 is bonded to the reflective layer 5, and a plurality of LED chips 2 and circuit patterns 3 are housed therein, and the pair of power supply pattern portions 3 c and 3 d are positioned outside the reflector 8. Yes. The reflector 8 is formed of, for example, a synthetic resin, and its inner peripheral surface is a reflecting surface. The reflecting surface of the reflector 8 can be formed by depositing or plating a metal material having a high reflectance such as Al or Ni, or by applying a white paint having a high visible light reflectance. Alternatively, white powder can be mixed into the molding material of the reflector 8 to make the reflector 8 itself white with high visible light reflectivity. As said white powder, white fillers, such as aluminum oxide, titanium oxide, magnesium oxide, barium sulfate, can be used. It is desirable that the reflecting surface of the reflector 8 is formed so as to gradually open in the irradiation direction of the LED lamp 1.

  The phosphor-containing resin layer 9 is made of a translucent material such as a transparent silicone resin or transparent glass. The phosphor particles used for forming the phosphor-containing resin layer 9 have an average particle diameter (D50) of 15 μm or more and 30 μm or less as described above, and the liquid transparent resin has a viscosity of 1 Pa · s or more and 3 Pa · s. The following are used. The liquid transparent resin containing the phosphor is solidified in the reflector 8 by evenly filling the surface of the reflective layer 5 and the LED chips 2 and bonding wires 6 arranged in a straight line. It is considered that the liquid transparent resin that has flowed between the surface of the reflective layer 5 and the bonding wire 6 has spread to each LED chip 2 and the bonding wire 6 due to a capillary phenomenon or the like. In addition, when the liquid transparent resin used for forming the phosphor-containing resin layer 9 is composed of two or more liquid transparent resins, the mixture of the two or more liquid transparent resins is mixed. The viscosity may be 1 Pa · s or more and 3 Pa · s or less. For example, in the present embodiment in which each LED chip 2 is a blue LED chip, a phosphor (illustrated) that converts the wavelength of primary light (blue) emitted from these elements to produce yellow light as secondary light having a different wavelength. However, as a preferred example, it is mixed in a substantially uniformly dispersed state.

  In the light emitting device of the present embodiment, the phosphor-containing resin layer 9 can evenly cover the LED chips 2 arranged side by side on the same surface on the white reflective layer 5, so that it is in a plurality of recesses on the substrate. Compared with the case where the light emitting elements are arranged one by one, the change in the color temperature of the entire light emitting device 1 can be suppressed, and the light emitting device 1 can be manufactured with a high yield. Moreover, since the average particle diameter (D50) of each phosphor is 15 μm or more and 30 μm or less, and the viscosity of the transparent resin before curing is 1 Pa · s or more and 3 Pa · s or less, it is injected onto the white reflective layer 5. It is possible to suppress the precipitation and deposition of the phosphor particles from the time of curing to the time of curing, thereby reducing the light emission efficiency and further emitting light uniformly.

  The sheet-like phosphor layer 10 has a relatively large surface area of the phosphor-containing resin layer 9 of the second embodiment and is in a state in which dust or the like is likely to adhere because it has a soft property. In order to prevent adhesion of dust and the like by covering this with the sheet-like phosphor layer 10, it is desirable to increase the hardness of the sheet-like phosphor layer 10. Specifically, silicone resin and silicone rubber are suitable.

  With this combination, part of the blue light emitted from the LED chip 2 passes through the phosphor-containing resin layer 9 without hitting the phosphor, while each fluorescent light hit by the blue light emitted from the LED chip 2 The body absorbs blue light, emits yellow light and red light, and the yellow light and red light are transmitted through the phosphor-containing resin layer 9 and the sheet-like phosphor layer 10, so that these two complementary colors are present. White light in which the average color rendering index Ra of the LED lamp 1 is improved by mixing color and red light can be realized.

  The light diffusion member 22 combined with the LED lamp 1 has a flat plate shape and is disposed in front of the reflector 8. Note that the reflector 8 may be provided with an extension projecting forward and the light diffusing member 22 may be supported there, or may be supported by a lighting fixture body (not shown) in which the LED lamp 1 is housed. The light diffusion member 22 has a difference between the transmittance of blue light of 400 nm to 480 nm and the transmittance of yellow light of 540 nm to 650 nm within 10%, and the transmittance of visible light is 90% or more 100 Those having a light diffusion performance of less than% can be suitably used. By using such a light diffusing member 22, the blue primary light and the yellow secondary light can be mixed by the light diffusing member 22, and the light diffusing member 22 can be white in which the color unevenness is suppressed.

  Next, Examples 1 to 3 of the present invention and evaluation results thereof will be described. A Y1-containing resin in which a first yellow phosphor Y1 having a dominant wavelength of 540 nm is blended in a proportion described later with respect to the silicone resin is applied and filled into a cup (concave) containing a blue light-emitting LED chip, and the Y1-containing resin is applied. A layer was formed and a red phosphor sheet was placed thereon.

  For the red phosphor sheet, the red phosphor R having a dominant wavelength of 650 nm is dispersed in a silicone resin, formed into a sheet with a thickness of 0.5 mm by the doctor blade method, and cured at 150 ° C. for 1 hour to cure the resin. It produced by making it. At this time, the blending ratio of the red phosphor R to the silicone resin was changed. In Example 1, the contents of the yellow phosphor Y1 and the red phosphor R are 5% and 4%, respectively, with respect to the total weight of the Y1-containing resin layer and the total weight of the R-containing resin sheet (red phosphor sheet). It was. In Example 2, the contents of the yellow phosphor Y1 and the red phosphor R were 5% and 8%, respectively, with respect to the total weight of the Y1-containing resin layer and the total weight of the red phosphor sheet. Furthermore, in Example 3, the contents of the yellow phosphor Y1 and the red phosphor R were 5% and 12%, respectively, with respect to the total weight of the Y1-containing resin layer and the total weight of the red phosphor sheet. And these red fluorescent substance sheets were each arrange | positioned on the Y1-containing resin layer, and the light-emitting device 11 shown in FIG. 1 was produced.

  Next, the chromaticity of light emission of these light emitting devices 11 was measured. In the first embodiment, the chromaticity represented by the point E1 in the CIE (x, y) chromaticity diagram shown in FIG. 4, the chromaticity represented by the point E2 in the second embodiment, and the point E3 in the third embodiment. It became the chromaticity represented. These points E1, E2 and E3 were almost on the black body locus a and showed light emission at a good color temperature (for example, 5000K). In the chromaticity diagram of FIG. 5, b1 indicates a linear shape in which the chromaticity of light emitted from the Y1-containing resin layer is linked, and this represents the chromaticity of blue light emitted from the LED chip, and yellow This is a straight line connecting points representing the chromaticity of yellow light emitted from the phosphor Y1 alone. Further, c represents a spectrum locus in which chromaticity points of respective wavelengths are connected.

  Furthermore, when the light emitting device 11 was produced using a red phosphor sheet containing red phosphors having different main wavelengths in the range of 590 to 640 nm, and the chromaticity, color rendering, and luminous efficiency of the emitted light were measured, It was found that the emission characteristics (emission color temperature, emission luminance, color rendering, etc.) can be changed by changing the phosphor sheet to one having a different main wavelength. That is, by changing the dominant wavelength of the red phosphor contained in the red phosphor sheet, it is possible to obtain a light emitting device 11 having a high chromaticity located on the locus of black body radiation and having a high color rendering property. It is also possible to obtain a light emitting device 11 that realizes a color temperature and has a design that is more excellent in luminous efficiency than color rendering.

1 is an enlarged cross-sectional view of a part of a light-emitting device showing an embodiment of the present invention. The enlarged front view which abbreviate | omitted some light emitting devices same as the above. Sectional drawing of the light emitting element and transparent adhesive of a light emitting device same as the above. The front view of a light-emitting device same as the above. The figure which represented the chromaticity of light emission of the light-emitting device obtained in Examples 1-3 on the CIE chromaticity diagram. The graph which shows the total light reflectance of the white resin material used for a light-emitting device same as the above. The table | surface which shows the reflectance and thermal resistance for every thickness of the insulating layer of a light emitting device same as the above. The table | surface which shows the temperature rise for every thickness of the insulating layer of a light-emitting device same as the above. The table | surface which shows the total light beam and ratio for each thickness of the insulating layer of a light-emitting device same as the above. The top view which shows the structure of 2nd Embodiment which applied the light-emitting device of this invention to the LED lamp. F2-F2 sectional view of the LED lamp shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Light emitting device, 13 ... Light emitting diode element as a light emitting element, 14 ... Board | substrate, 15 ... Insulating layer, 16 ... Circuit pattern layer, 16a1, 16b1 ... Connection part as a light emitting element connection part, 17 ... Reflector, 19 ... Housing part, 21 ... transparent adhesive, 22 ... projection part, 27 ... phosphor-containing resin layer, 30 ... sheet-like phosphor layer.

Claims (6)

A substrate;
A white insulating layer provided on the substrate;
A circuit pattern layer having a light emitting element connection portion provided on the insulating layer;
A light emitting element disposed on the insulating layer and electrically connected to the light emitting element connecting portion of the circuit pattern layer;
A phosphor-containing resin layer containing a yellow phosphor that emits yellow light or orange light when excited by blue light emitted from the light emitting element, and is disposed so as to cover the light emitting element;
A sheet-like phosphor layer that contains a red phosphor that emits red light when excited by blue light emitted from a light-emitting element, and is disposed on the phosphor-containing resin layer;
A light-emitting device comprising: A substrate;
A white insulating layer provided on the substrate;
A circuit pattern layer having a light emitting element connection portion provided on the insulating layer;
A receiving portion provided on the insulating layer and the circuit pattern layer of the substrate and having an opening on the light emitting element connecting portion of the insulating layer and the circuit pattern layer of the substrate corresponding to the light emitting element arrangement position. A reflector configured such that the light emitting element connection portion of the circuit pattern layer is positioned on the substrate;
A light emitting element disposed on the insulating layer in a central area of the bottom surface in the housing portion and electrically connected to the light emitting element connection portion of the circuit pattern layer located in the peripheral area in the housing portion;
A phosphor-containing resin layer containing a yellow phosphor that emits yellow light or orange light when excited by blue light emitted from the light emitting element, and is disposed so as to cover the light emitting element;
A sheet-like phosphor layer that contains a red phosphor that emits red light when excited by blue light emitted from the light-emitting element, and is disposed on the phosphor-containing resin layer;
A light-emitting device comprising:   The light emitting device according to claim 2, wherein the ratio of the surface area of the light emitting element connection portion to the surface area of the bottom surface in the housing portion is 50% or less.   The light-emitting device according to claim 1, wherein the light-emitting element is fixed on the insulating layer with a transparent adhesive.   5. The light emitting device according to claim 1, wherein the reflectance of the surface of the insulating layer is 85% or more in a wavelength range of 400 to 740 nm.   The light emitting device according to claim 1, wherein the insulating layer has a thickness in a range of 30 μm to 90 μm.