JP2012028736A - Led lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED lighting device capable of efficiently guiding light to the outside thereof and having high electrical connection reliability.SOLUTION: An LED lighting device 1 includes: a reflection base plate 2; a first resin layer 3 formed on an inner circumferential surface of a recessed portion 24 provided on the reflection base plate 2; a second resin layer 4 formed on the first resin layer 3; a third resin layer 5 formed so as to cover the second resin layer 4; and an LED mounted circuit board 6 including a light-emitting diode 64. In the device 1, the second resin layer 4 is formed so as to fill the recess 24, thereby preventing the light-emitting diode 64 from losing electrical connection with the circuit board even when the LED lighting device 1 is subjected to external impact. A refractive index of the second resin layer 4 is lower than that of the light-emitting diode 64 and higher than that of air, thus reducing the occurrence of total reflection inside the light-emitting diode 64, compared to the case that air is used instead of the second resin layer 4.

Description

  The present invention relates to an LED illumination device that emits reflected light.

  An illumination device using an LED (light emitting diode) element as a light source (hereinafter referred to as an LED illumination device) has high energy saving efficiency and a long life. Some LED illuminating devices reduce glare by irradiating the reflected light after reflecting the light emitted from the LED element on a reflection surface.

  This type of conventional LED illumination device will be described with reference to FIG. As shown in FIG. 9, the LED lighting device 101 is mounted on the reflective substrate 2, the resin layer 3 formed on the inner peripheral surface of the recess 24 provided on the reflective substrate 2, and the reflective substrate 2. LED mounting board 6. The inner peripheral surface of the recess 24 is a light reflecting surface 26 that reflects light. The resin layer 3 contains a yellow phosphor. The LED mounting substrate 6 includes LED elements 64. The LED element 64 is disposed on the opening periphery of the recess 24. The illustrated arrow represents an optical path emitted from the LED element 64.

  When power from the outside is supplied to the LED element 64, blue light is emitted from the LED element 64. This blue light passes through the air and reaches the resin layer 3. In the resin layer 3, a part of blue light is irradiated to the yellow phosphor. Blue light applied to the yellow phosphor is converted into yellow light. This yellow light is diffused from the yellow phosphor and reaches the light reflecting surface 26. On the other hand, blue light that is not irradiated onto the yellow phosphor passes through the resin layer 3 and reaches the light reflecting surface 26.

  These blue light and yellow light are reflected on the light reflecting surface 26. The reflected light is irradiated from the opening of the recess 24 to the outside. At this time, it is felt that white light is emitted from the LED lighting device 1 by combining the blue light and the yellow light.

  In addition to the above configuration, for example, there is an LED illumination device as disclosed in Patent Document 1. In this LED lighting device, a light transmitting body is formed so as to cover the opening of the concave portion, and after the blue light and yellow light are reflected by the light reflecting surface, they pass through the light transmitting body and go outside the LED lighting device. Irradiated.

JP 2001-243821 A

  However, in the LED lighting device as described above, since the refractive index of the LED element and the refractive index of air are greatly different, the light emitted from the LED element cannot be efficiently guided outside the LED lighting device. There is. Moreover, when an impact is given to the LED lighting device from the outside of the LED lighting device, the electrical connection between the LED element and the base material may be disconnected.

  The present invention solves the above-described problems, and an object thereof is to provide an LED lighting device that can efficiently guide light to the outside of the LED lighting device and has high electrical connection reliability.

  The LED lighting device of the present invention comprises a reflection substrate having a recess on one surface, and an inner peripheral surface of the recess serving as a light reflection surface, and an LED element that emits light to the light reflection surface, An LED lighting device that emits light reflected by a light reflecting surface from an opening of the concave portion, the first resin layer formed on the light reflecting surface, and filling the concave portion on the first resin layer A second resin layer, the refractive index of the first resin layer and the refractive index of the second resin layer are the same, and the second resin layer includes the LED element and the second resin layer. The substrate electrically connected to the LED element is sealed, and the refractive index of the second resin layer is smaller than the refractive index of the LED element and larger than the refractive index of air.

  In this LED lighting device, it is preferable that the second resin layer is filled so as to cover the LED element.

  In this LED lighting device, a light diffusing unit capable of diffusing light is provided between the LED element and the light reflecting surface, and the light diffusing unit diffuses light emitted from the LED element a plurality of times. It is preferable.

  In this LED illumination device, it is preferable that the light diffusing unit diffuses the direct light emitted from the LED element and the reflected light reflected by the light reflecting surface.

  In this LED lighting device, it is preferable that a third resin layer is formed so as to cover the second resin layer.

  In this LED illumination device, it is preferable that the light diffusing means is provided at least in the first resin layer, the second resin layer, or the third resin layer.

  In this LED illumination device, the light diffusing means is preferably a translucent member, and diffuses light by having a refractive index different from that of the resin covering the periphery.

  In this LED illumination device, it is preferable that the light diffusing unit has a phosphor material, and radiates light emitted from the LED element after wavelength conversion.

  In this LED illumination device, it is preferable that the light diffusing means is provided on the light reflecting surface.

  In this LED illumination device, it is preferable that the light diffusing unit diffuses light by unevenness formed on the surface of the light reflecting surface.

  In this LED lighting device, the light diffusing unit is provided at least at the interface between the first resin layer and the second resin layer, or at the interface between the second resin layer and the third resin layer. It is preferable.

  In this LED lighting device, the light diffusing means is formed by bubbles formed at the interface between the first resin layer and the second resin layer, or at the interface between the second resin layer and the third resin layer. It is preferable that the light diffuses.

  In this LED lighting device, it is preferable that the second resin layer is formed in a convex shape.

  In this LED lighting device, the refractive index of the third resin layer is preferably smaller than the refractive index of the second resin layer and larger than the refractive index of air.

  In this LED lighting device, it is preferable that the LED element is disposed on an opening periphery of the recess.

  According to the LED illumination device of the present invention, since the refractive index of the second resin layer is smaller than the refractive index of the LED element and larger than air, conventional air is used instead of the second resin layer. Compared with the LED, total reflection is less likely to occur in the LED element. As a result, light can be efficiently guided to the outside of the LED lighting device. In addition, the LED element and the base material electrically connected to the LED element are sealed by the second resin layer, so that even when an impact is applied to the LED lighting device from the outside, the LED element and the base material The electrical connection is difficult to disconnect. Therefore, the electrical connection reliability of the LED lighting device can be improved. Moreover, since the light radiate | emitted from the LED element is reflected in a light reflection surface, the glare by the light irradiated from a LED lighting apparatus is reduced.

(A) is sectional drawing of the LED lighting apparatus which concerns on 1st Embodiment, Comprising: The AA sectional view taken on the line of (b), (b) is a top view of the LED lighting apparatus. (A) is sectional drawing of the LED lighting apparatus which concerns on 2nd Embodiment, Comprising: The AA sectional view taken on the line of (b), (b) is a top view of the LED lighting apparatus. (A) is sectional drawing of the LED lighting apparatus which concerns on 3rd Embodiment, (b) And (c) is sectional drawing for demonstrating the effect | action of the LED lighting apparatus. (A) is sectional drawing of the LED lighting apparatus which concerns on 4th Embodiment, (b) And (c) is sectional drawing for demonstrating an effect | action of the LED lighting apparatus. (A) is sectional drawing of the LED lighting apparatus which concerns on 5th Embodiment, (b) is sectional drawing for demonstrating an effect | action of the LED lighting apparatus. (A) And (b) is sectional drawing for demonstrating an effect | action of the LED lighting apparatus which concerns on 5th Embodiment. Sectional drawing of the LED lighting apparatus which concerns on 6th Embodiment. Sectional drawing of the LED lighting apparatus which concerns on 7th Embodiment, and partial expanded sectional view of the light reflection surface of the LED lighting apparatus. Sectional drawing of the conventional LED lighting apparatus.

  Hereinafter, an LED lighting device according to a first embodiment of the present invention will be described with reference to the drawings.

  As shown in FIGS. 1A and 1B, the LED lighting device 1 includes a reflective substrate 2 and a first resin layer formed on the inner peripheral surface of a recess 24 provided on the reflective substrate 2. 3, a second resin layer 4 formed on the first resin layer 3, a third resin layer 5 formed to cover this, and an LED mounting substrate 6. The second resin layer 4 is formed so that the recess 24 is filled. The LED mounting substrate 6 has LED elements 64 mounted thereon. The illustrated arrow represents an optical path emitted from the LED element 64.

  The first resin layer 3 contains a yellow phosphor. The yellow phosphor converts blue light emitted from the LED element 64 into yellow light, and diffuses the yellow light. The inner peripheral surface of the recess 24 is a light reflecting surface 26 that reflects blue light emitted from the LED element 64 and yellow light diffused from the yellow phosphor. The second resin layer 4 seals the LED element 64 and a base material (a circuit pattern 63 and a bonding material 65 described later) electrically connected to the LED element 64. The second resin layer 4 is formed in a convex shape on the reflective substrate 2.

  The materials of the first resin layer 3 and the second resin layer 4 are selected so that their refractive indexes are the same. In this case, the refractive index of the first resin layer 3 and the refractive index of the second resin layer 4 are smaller than the refractive index of the LED element 64 and larger than the refractive index of air. Therefore, compared with the case where air is used instead of the second resin layer 4, it is possible to reduce the occurrence of total reflection in the LED element 64. As a result, the light emitted from the LED element 64 can be efficiently guided to the outside of the LED lighting device 1.

The reflective substrate 2 includes a base substrate 21, an insulating layer 22 formed on the base substrate 21,
And a circuit pattern 23 formed on the insulating layer 22. As the material of the base substrate 21, it is preferable to use a material having excellent thermal conductivity such as copper, aluminum, or aluminum nitride. As a material of the circuit pattern 23, it is preferable to use copper, gold or aluminum.

  The first resin layer 3 is formed, for example, by mixing a transparent material such as a silicone resin and a granular yellow phosphor. As the material of the second resin layer 4, the same material as the material having transparency mixed in the first resin layer 3 is used. The refractive index of the second resin layer 4 is smaller than the refractive index of the LED element 64 and larger than the refractive index of air. As the material of the third resin layer 5, it is preferable to use the same material as that of the second resin layer 4. Moreover, as a material of the 3rd resin layer 5, it is preferable to use the material whose refractive index is smaller than the refractive index of the 2nd resin layer 4, and larger than the refractive index of air. Specifically, it is preferable to use silicon resin or acrylic resin as the material of the third resin layer 5. The shape of the third resin layer 5 is preferably hemispherical.

  The LED mounting substrate 6 includes a base substrate 61, an insulating layer 62 formed on the base substrate 61, a circuit pattern 63 formed on the insulating layer 62, and an LED bonded to the circuit pattern 63. Element 64.

  The circuit pattern 63 of the LED mounting substrate 6 and the circuit pattern 23 of the reflective substrate 2 are bonded via a bonding material 66. Thereby, the LED element 64 is electrically connected to an external power source via the bonding material 65, the circuit pattern 63 of the LED mounting substrate 6, the bonding material 66, and the circuit pattern 23 of the reflective substrate 2. . The LED element 64 is disposed on the periphery of the opening 25 of the recess 24.

  The LED element 64 is formed by sequentially stacking a buffer layer, an n-type semiconductor layer, a light emitting layer, and a p-type semiconductor layer on a substrate made of, for example, sapphire or gallium nitride. An n-type electrode is formed on the surface of the n-type semiconductor layer, and a current diffusion film and a p-type electrode are formed on the surface of the p-type semiconductor layer. The current diffusion film is made of a conductive material having a high reflectance.

  As the bonding materials 65 and 66, it is preferable to use a conductive material such as gold tin, gold bump, silver paste, or lead-free solder.

  Next, a method for manufacturing the LED lighting device 1 will be described. In this example, a case where a face-down LED chip (hereinafter referred to as LED element 64) is used will be described.

  First, the LED element 64 is mounted on the circuit pattern 63. Specifically, a bonding material 65 such as a gold bump is formed in a region where the LED element 64 on the circuit pattern 63 of the LED mounting substrate 6 is to be mounted. Next, the LED element 64 and the circuit pattern 63 are bonded by ultrasonic waves through the bonding material 65. Thereby, the LED element 64 is mounted on the circuit pattern 63.

  Subsequently, the first resin layer 3 is formed on the light reflecting surface 26 of the reflective substrate 2. Specifically, the recess 24 is formed on one surface of the reflective substrate 2. For example, the first resin layer 3 is prepared by mixing a transparent material such as a silicone resin and a granular yellow phosphor. After the produced first resin layer 3 is applied on the light reflecting surface 26, the light reflecting surface 26 to which the first resin layer 3 is applied is heated. Thereby, the 1st resin layer 3 and the light reflection surface 26 adhere | attach.

  Subsequently, the reflective substrate 2 and the LED mounting substrate 6 are bonded. Specifically, a bonding material 66 such as lead-free solder is applied to a region where the LED mounting substrate 6 and the circuit pattern 23 of the reflective substrate 2 are to be bonded. Then, after arrange | positioning the LED mounting substrate 6 on the circuit pattern 23, reflow heating is carried out. Thereby, the reflective substrate 2 and the LED mounting substrate 6 are joined.

  Subsequently, the second resin layer 4 is filled between the recess 24 and the third resin layer 5. Specifically, a hemispherical third resin layer 5 having a recess is formed. Next, the second resin layer 4 is filled in the recess 24 of the reflective substrate 2 so as to cover the LED element 64. Next, the second resin layer 4 is filled in the recesses of the third resin layer 5. The third resin layer 5 filled with the second resin layer 4 is disposed on the LED mounting substrate 6, and the third resin layer 5 and the LED mounting substrate 6 are heated and bonded. Thereby, the LED lighting device 1 is completed.

  Next, the operation of the LED lighting device 1 configured as described above will be described. First, when power is supplied to the LED element 64 from the outside, blue light is emitted from the LED element 64.

  Blue light emitted from the LED element 64 passes through the second resin layer 4 and reaches the first resin layer 3. In this case, the refractive index of the second resin layer 4 is smaller than the LED element 64 and larger than the refractive index of air. Therefore, compared with the case where air is used instead of the second resin layer 4, it is possible to reduce the occurrence of total reflection in the LED element 64.

  A part of the blue light reaching the first resin layer 3 is irradiated on the yellow phosphor mixed in the first resin layer 3. Blue light applied to the yellow phosphor is converted into yellow light. Then, yellow light is diffused from the yellow phosphor. The diffused yellow light reaches the light reflecting surface 26 of the reflective substrate 2. Of the blue light that has reached the first resin layer 3, the blue light that has not been irradiated to the yellow phosphor passes through the first resin layer 3 and reaches the light reflecting surface 26.

  The blue light and yellow light that have reached the light reflecting surface 26 are reflected by the light reflecting surface 26 and pass through the first resin layer 3 again. In this case, part of the blue light reflected by the light reflecting surface 26 is irradiated again on the yellow phosphor mixed in the first resin layer 3. Blue light applied to the yellow phosphor is converted into yellow light. Then, yellow light is diffused from the yellow phosphor.

  The blue light and yellow light generated in this way are guided to the outside of the LED lighting device 1 through the second resin layer 4 and further through the third resin layer 5. It is felt that white light is emitted from the LED lighting device 1 by combining the blue light and the yellow light.

  As described above, according to the LED lighting device 1 according to the present embodiment, the refractive index of the second resin layer 4 is smaller than the refractive index of the LED element 64 and larger than air. Therefore, compared with the case where air is used instead of the second resin layer 4, it is possible to reduce the occurrence of total reflection in the LED element 64. As a result, light can be efficiently guided to the outside of the LED lighting device 1. Further, the LED element 64 and the substrate electrically connected to the LED element 64 are sealed by the second resin layer 4, so that the LED element can be applied even when an impact is applied to the LED lighting device 1 from the outside. It is difficult for the electrical connection between 64 and the base material to come off. Therefore, the electrical connection reliability of the LED lighting device 1 can be improved. Moreover, since the light radiate | emitted from the LED element 64 is reflected in the light reflection surface 26, the glare by the light irradiated from the LED lighting apparatus 1 is reduced.

  Furthermore, since the first resin layer 3 containing the phosphor is formed on the light reflecting surface 26, the heat of the phosphor can be efficiently radiated to the reflecting substrate, and the phosphor can be efficiently irradiated with light. The color can be converted. In the present embodiment, an example in which the first resin layer 3 includes a phosphor has been described. However, when the LED element 64 that emits white light is used, this phosphor is not necessary. Similarly, when the LED element 64 emits blue light and is an LED illumination device that emits blue light, this phosphor is not necessary.

  Further, the second resin layer 4 is formed so as to cover the LED element 64. Therefore, the LED element 64 can be reliably sealed. As a result, the electrical connection reliability of the LED lighting device 1 can be further improved.

  In addition, the second resin layer is formed in a convex shape on the reflective substrate 2, and further, the third resin layer 5 is formed so as to cover the second resin layer 4. Therefore, it is possible to reduce the occurrence of total reflection in the second resin layer 4. As a result, light can be emitted to the outside of the LED lighting device 1 more efficiently. The third resin layer 5 is not necessarily formed.

  Further, the refractive index of the third resin layer is smaller than the refractive index of the second resin layer and larger than the refractive index of air. Therefore, it is possible to reduce the occurrence of total reflection in the second resin layer 4. As a result, light can be guided to the outside of the LED lighting device 1 more efficiently.

  Further, the LED elements 64 are arranged on the 25 peripheral edge of the concave portion 24 of the reflective substrate 2. Therefore, the reduction in the area of the opening 25 of the recess 24 due to the LED mounting substrate 6 can be minimized. As a result, light can be guided to the outside of the LED lighting device more efficiently.

  Next, an LED lighting device according to a second embodiment of the present invention will be described with reference to FIGS. 2 (a) and 2 (b). As shown in FIGS. 2A and 2B, the LED lighting device 1 a according to this embodiment includes a plurality (eight in this example) of LED elements 64 arranged at the periphery of the opening 25 of the recess 24. Yes. Other configurations are the same as those of the first embodiment. In the present embodiment, the same members as those in the first embodiment are denoted by the same reference numerals.

  When power from the outside is supplied to the plurality of LED elements 64 arranged at the periphery of the opening 25, blue light is emitted from the plurality of LED elements 64. In the present embodiment, in addition to the operational effects obtained by the first embodiment, since the number of LED elements is large, more light is emitted from the LED elements 64. Therefore, more light is guided to the outside of the LED lighting device 1a.

  Next, an LED lighting device according to a third embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 3A, the LED lighting device 1 b has a translucent member 7 as a light diffusing unit in the second resin layer 4. The refractive index of the translucent member 7 is different from the refractive index of the second resin layer 4 which is a resin covering the periphery. That is, the light diffusing means in the present embodiment totally reflects the light from the LED element 64 in various directions at the interface between the light transmissive member 7 and the second resin layer 4 having different refractive indexes. It is intended to diffuse. The first resin layer 3 contains no phosphor. Other configurations are the same as those in the first embodiment.

  In the present embodiment, the translucent member 7 is located in the vicinity of the interface between the first resin layer 3 and the second resin layer 4 in the second resin layer 4. As the material of the translucent member 7, it is preferable to use glass beads or the like. In order to efficiently totally reflect the light from the LED element 64, the difference in refractive index from the second resin layer 4 is large. It is more preferable to use a material. Further, in the case where the third resin layer 5 is formed so as to cover the second resin layer 4 in order to increase the physical strength as in the LED lighting device 1b, the translucent member 7 is at least What is necessary is just to be provided in the 1st resin layer 3, the 2nd resin layer 4, or the 3rd resin layer 5. FIG. The LED element 64 may be one that irradiates visible light or one that irradiates light other than visible light such as ultraviolet light or infrared light.

  As shown in FIG. 3 (b), the light emitted from the LED element 64 passes through the second resin layer 4 and is irradiated to the light transmissive member 7 and diffused. Then, the diffused light passes through the first resin layer 3 and is applied to the light reflecting surface 26, and after being reflected, a part of the reflected light passes through the first resin layer 3 and the second resin layer 4. Then, it is diffused again by the translucent member 7. As shown in FIG. 3C, when the light emitted from the LED element 64 is not diffused by the translucent member 7, the light is reflected by the light reflecting surface 26 and then a part of the reflected light. Is diffused by the translucent member 7. In addition to the case where the light travels as described above, immediately after the light emitted from the LED element 64 is diffused by one translucent member 7, this diffused light is irradiated to other translucent members 7 around it. And may be spread again. By doing so, the light from the LED element 64 always passes through the resin layer until the light from the LED element 64 is guided to the outside of the LED lighting device 1b, so that the light from the LED element 64 is reliably diffused. be able to.

  According to the LED lighting device 1b of the present embodiment, the same effect as in the first embodiment is obtained, and light from the LED element 64 is diffused a plurality of times in an arbitrary direction by the translucent member 7. Therefore, this variation in light can be suppressed. For this reason, it is possible to prevent the light from having an angle dependency, and as a result, uniform light is emitted from the LED illumination device 1b. It can be made uniform.

  By the way, in the conventional LED lighting device, for example, there is a problem that the light output intensity in the direction directly above or laterally of the LED element is large and the light output intensity emitted from the LED element cannot be made constant with respect to the radiation angle. . On the other hand, according to the LED lighting device 1b, since the variation in the light from the LED element 64 can be suppressed as described above, the light can be made to have no angle dependency. Can be made constant with respect to the radiation angle.

  Further, according to the present embodiment, when the LED lighting device 1b and the lens are used in combination, it is not necessary to consider the lens arrangement corresponding to the variation in the light from the LED lighting device 1b in the lens design stage. Lens design can be facilitated.

  Further, according to the present embodiment, the translucent member 7 can diffuse not only the direct light from the LED element 64 but also the reflected light reflected by the light reflecting surface 26. Therefore, a large amount of light can be diffused by increasing the number of times of irradiating light to the translucent member 7 without providing light diffusing means for both direct light and reflected light. Therefore, the amount of the translucent member 7 (for example, glass beads) used as the light diffusing means can be reduced, and the cost can be reduced. In the case of diffusing only the direct light, in the LED lighting device having a structure in which the light emitted from the conventional LED element is extracted as it is, the member including the translucent member 7 is replaced with the LED element in order to reduce glare. Shown when installed above.

  Furthermore, according to the present embodiment, by adjusting the amount of the first resin layer 3, the light diffused by the translucent member 7 is reflected by the light reflecting surface 26 and is again applied to the translucent member 7. The optical path length until returning can be changed. For example, if the amount of the first resin layer 3 is increased and the optical path length is made sufficiently long, the diffused light can be mixed accordingly. In this embodiment, since the adjustment method of the quantity of the 1st resin layer 3 is based also on the angle dependence of the light intensity radiated | emitted from the LED element 64, an amount is adjusted according to the performance of each LED element 64 to be used. Adjust it. In this way, the degree of light diffusion from the LED element 64 can be easily controlled.

  Next, an LED lighting device according to a fourth embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 4A, the LED illumination device 1 c of this embodiment includes a phosphor as a light diffusing means in the second resin layer 4, and this phosphor is emitted light from the LED element 64. The wavelength is converted and diffused. That is, the light diffusing means of the present embodiment substantially emits light from the LED element 64 by irradiating the phosphor with the light from the LED element 64 and radiating the wavelength-converted light around the phosphor. It diffuses incident light. Other configurations are the same as those of the third embodiment.

  In the present embodiment, the phosphor is located in the vicinity of the interface between the first resin layer 3 and the second resin layer 4 in the second resin layer 3, and in the drawing, the second resin layer 4. A portion containing the phosphor is shown as a phosphor-containing portion 8. As the phosphor of this embodiment, for example, the yellow phosphor used in the first embodiment can be used.

  As shown in FIG. 4B, the emitted light from the LED element 64 passes through the second resin layer 4 and is irradiated to the phosphor-containing portion 8, and a part of the irradiated light hits the phosphor and is wavelength-converted. , Diffuse radiation. And after this diffused radiation light is reflected by the light reflection surface 26, a part of this reflected light is again irradiated to a fluorescent substance, and is diffused and radiated. Further, as shown in FIG. 4C, the light that does not hit the phosphor out of the light emitted from the LED element 64 is reflected by the light reflecting surface 26 and irradiated again to the phosphor-containing portion 8. A part of the irradiation light hits the phosphor, undergoes wavelength conversion, and is diffused and emitted.

  In a conventional LED lighting device in which a member containing a phosphor is installed on an LED element, light from the LED element is applied to the phosphor and the wavelength-converted light is taken out as it is, but the light from the LED element is It does not necessarily hit all phosphors, and there is a possibility that the conversion efficiency of the phosphors is deteriorated. However, according to the present embodiment, the direct light from the LED element 64 and the reflected light from the light reflecting surface 26 can be applied to the phosphor, and thus the light may reach the phosphor twice. Yes, the probability of shining light on the phosphor can be increased.

  Next, an LED lighting apparatus according to a fifth embodiment of the present invention will be described with reference to FIGS. As shown to Fig.5 (a), the LED lighting apparatus 1d of this embodiment contains the fluorescent substance as a light-diffusion means in the 1st resin layer 3 and the 2nd resin layer 4, respectively. That is, the light diffusing means of the present embodiment irradiates the phosphors in the two types of resin layers with the light from the LED element 64, and emits the light around these phosphors. Other configurations are the same as those in the fourth embodiment.

  In the present embodiment, the phosphor in the first resin layer 3 is located near the interface between the first resin layer 3 and the light reflecting surface 26, and the phosphor in the second resin layer 4 is the first The resin layer 3 and the second resin layer 4 are located in the vicinity of the interface. In the figure, the location containing the phosphor in the first resin layer 3 is defined as the first phosphor-containing portion 8a, and the location containing the phosphor in the second resin layer 4 is designated as the second fluorescence. It is shown as a body containing part 8b. The phosphor materials contained in the first phosphor-containing portion 8a and the second phosphor-containing portion 8b may be the same phosphor material or different types of phosphor materials. .

  As shown in FIG. 5 (b), the emitted light from the LED element 64 is irradiated to the second phosphor-containing portion 8b, and a part of the irradiated light is fluorescent in the second phosphor-containing portion 8b. It hits the body, undergoes wavelength conversion and diffuses radiation. Further, as shown in FIG. 6A, the light that did not hit the phosphor is irradiated to the first phosphor-containing portion 8a, and a part of the irradiated light is irradiated to the first phosphor-containing portion 8a. It hits the phosphor inside. Moreover, as shown in FIG.6 (b), the reflection reflected by the light reflection surface 26 among the lights which did not hit the fluorescent substance in the 1st fluorescent substance containing part 8a and the 2nd fluorescent substance containing part 8b The light is irradiated again on the second phosphor-containing portion 8b, and a part of the irradiated light hits the phosphor in the second phosphor-containing portion 8b. In addition to the case where the light travels as described above, the reflected light reflected by the light reflecting surface 26 is again irradiated to the first phosphor-containing portion 8a, and a part of this irradiated light is the first phosphor-containing portion. It may hit the phosphor in 8b.

  According to this embodiment, the direct light from the LED element 64 and the reflected light from the reflecting surface 26 are applied to the phosphors in different places such as the first phosphor-containing portion 8a and the second phosphor-containing portion 8b. Since each can be applied, the conversion efficiency of the phosphor can be increased.

  Further, according to the present embodiment, the phosphor is divided into the first resin layer 3 (first phosphor-containing portion 8a) and the second resin layer 4 (second phosphor-containing portion 8b). can do. In this case, a part of the member containing the phosphor that generates heat when converting the wavelength is placed on the first resin layer 3 in the vicinity of the base substrate 21 with good heat dissipation, so that the heat is more effectively removed. As a result, heat generation of the LED lighting device 1d can be suppressed. In this way, by suppressing the heat generation that causes a decrease in the light emission efficiency of the LED element 64 and the deterioration of the members, it is possible to manufacture a product with good quality in a simple and inexpensive manner without requiring an expensive and complicated configuration.

  Next, an LED lighting device according to a sixth embodiment of the present invention will be described with reference to FIG. The LED lighting device 1e of the present embodiment is one in which bubbles 9 are formed at the interface between the first resin layer 3 and the second resin layer 4 as light diffusing means. That is, the light diffusing means of the present embodiment diffuses the light from the LED element 64 by totally reflecting it at the interface between the bubble 9 and the first resin layer 3 and the second resin layer 4. Other configurations are the same as those of the fifth embodiment.

  Since the air bubbles 9 are filled with air, the bubbles 9 are translucent and have a refractive index different from those of the first resin layer 3 and the second resin layer 4 which are resins covering the periphery. For this reason, it can be considered that it functions similarly to the translucent member 7 of the third embodiment.

  The method for forming the bubbles 9 is not particularly limited. For example, a method in which the bubbles 9 are included in the first resin layer 3 in advance and the resin layer is cured may be used. Alternatively, the first resin layer 3 and the second resin layer 4 that have poor adhesion to each other may be adhered to each other, and the bubbles 9 may be formed by peeling the portions having low adhesion to each other.

  According to this embodiment, since the bubble 9 can be regarded as the translucent member 7, the same effect as that of the third embodiment can be obtained. The LED lighting device 1e is provided with bubbles 9 at least at the interface between the first resin layer 3 and the second resin layer 4 or at the interface between the second resin layer 4 and the third resin layer 5. The above effects can be achieved.

  Further, according to the present embodiment, the interface where the bubble 9 is formed is in a path through which the light from the LED element 64 always passes before and after being reflected by the light reflecting surface 26. 9 can be easily irradiated and light can be sufficiently diffused.

  Next, an LED lighting device according to a seventh embodiment of the present invention will be described with reference to FIG. In the LED illumination device 1f of the present embodiment, the light reflecting surface 26 is formed in a concavo-convex shape as light diffusing means. That is, the light diffusing unit of the present embodiment irradiates the light from the LED element 64 onto the unevenness of the light reflecting surface 26 and repeatedly performs the diffusion. Other configurations are the same as those of the sixth embodiment.

  Light emitted from the LED element 64 passes through the second resin layer 4 and the first resin layer 3 and is applied to the light reflecting surface 26. Since the unevenness of the light reflecting surface 26 extends along the recessed portion 24, a part of the light reflected by the light reflecting surface 26 is irradiated again on the light reflecting surface 26.

  According to the present embodiment, since the light reflecting surface 26 is formed in an uneven shape, the contact area between the light reflecting surface 26 and the first resin layer 3 can be increased, and the heat transmitted from the LED element 64 is effective. Heat can be released. As a result, the heat generation of the LED lighting device 1f can be suppressed, the light output can be increased, and as a result, the appliance efficiency can be increased.

  Further, according to the present embodiment, the uneven shape is formed along the concave portion 24 of the base substrate 21, and is diffused by the light reflecting surface 26 as compared with the case where the uneven shape is formed along a straight line, for example. Since light becomes easy to irradiate the light reflecting surface 26 again, the light can be sufficiently diffused.

  The present invention is not limited to the configuration of each of the embodiments described above, and various modifications are possible without departing from the spirit of the invention as follows. For example, the material of the base substrate 21 of the reflective substrate 2 is not limited to a material having excellent thermal conductivity such as copper, aluminum, or aluminum nitride, and plastic or epoxy resin may be used. When a material having a high reflectance is used as the material of the base substrate 21, the inner peripheral surface of the recess 24 is polished. On the other hand, when a material with low reflectance is used as the material of the base substrate 21, a material with high reflectance such as silver or aluminum is formed on the inner peripheral surface of the recess 24. For example, a material capable of diffusing irradiated light such as barium sulfate may be applied to the inner peripheral surface of the recess 24.

  Further, the shape of the reflective substrate 2 may be a box shape, a bowl shape or a dome shape opened in one direction. In addition, the material of the resin having transparency mixed with the first resin layer 3 is not limited to the silicone resin, and for example, an acrylic resin or an epoxy resin that can be in close contact with the light reflecting surface 26 may be used. Further, a red phosphor or a green phosphor may be used instead of the yellow phosphor mixed in the first resin layer 3. When the blue light emitted from the LED elements 64 and 64a is applied to the red phosphor, the red light is diffused from the red phosphor. Further, when the blue light emitted from the LED elements 64 and 64a is applied to the green phosphor, the green light is diffused from the green phosphor. The bonding material 65 may be an insulating material such as a silicone resin or an epoxy resin depending on the material of the LED elements 64 and 64a. Further, the shape of the third resin layer 5 may be a hemisphere and the inside of the hemisphere may be a recess. In the third to seventh embodiments, a plurality of LED elements 64 may be arranged on the opening periphery of the recess 24.

DESCRIPTION OF SYMBOLS 1,1a LED lighting apparatus 2 Reflective substrate 7 Translucent member 8 Phosphor containing part 8a First phosphor containing part 8b Second phosphor containing part 21 Base substrate 22 Insulating layer 23 Circuit pattern 24 Recess 25 Open 26 Light reflecting surface 3 First resin layer 4 Second resin layer 5 Third resin layer 6 LED mounting substrate 61 Base substrate 62 Insulating layer 63 Circuit pattern 64 LED elements 65 and 66 Bonding material

Claims (15)

A reflective substrate having a concave portion on one surface, and an inner peripheral surface of the concave portion being a light reflecting surface;
An LED element that emits light to the light reflecting surface;
An LED illumination device that emits reflected light from the light reflecting surface from the opening of the recess,
A first resin layer formed on the light reflecting surface;
A second resin layer filled in the recesses on the first resin layer,
The refractive index of the first resin layer and the refractive index of the second resin layer are the same,
The second resin layer seals the LED element and a substrate electrically connected to the LED element, and the refractive index of the second resin layer is smaller than the refractive index of the LED element, and air An LED illumination device having a refractive index greater than that of the LED illumination device.   The LED lighting device according to claim 1, wherein the second resin layer is filled so as to cover the LED element.   A light diffusing unit capable of diffusing light is provided between the LED element and the light reflecting surface, and the light diffusing unit diffuses light emitted from the LED element a plurality of times. The LED lighting device according to claim 1 or 2.   The LED lighting device according to claim 3, wherein the light diffusing unit diffuses the direct light emitted from the LED element and the reflected light reflected by the light reflecting surface.   The LED lighting device according to any one of claims 1 to 4, wherein a third resin layer is formed so as to cover the second resin layer.   6. The LED lighting device according to claim 5, wherein the light diffusing means is provided in at least the first resin layer, the second resin layer, or the third resin layer.   7. The light diffusing means is a translucent member, and diffuses light by having a refractive index different from that of the resin covering the periphery. LED lighting device of Claim.   7. The light diffusing means includes a phosphor material, and radiates light emitted from the LED element after wavelength conversion. LED lighting device of Claim.   The LED illumination device according to claim 3, wherein the light diffusing unit is provided on the light reflecting surface.   The LED lighting device according to claim 9, wherein the light diffusing unit diffuses light by unevenness formed on a surface of the light reflecting surface.   The light diffusing means is provided at least at an interface between the first resin layer and the second resin layer, or at an interface between the second resin layer and the third resin layer. Claim | item 5 or the LED lighting apparatus of Claim 6.   The light diffusing means diffuses light by bubbles formed at the interface between the first resin layer and the second resin layer, or at the interface between the second resin layer and the third resin layer. The LED illumination device according to claim 11, wherein   The LED lighting device according to any one of claims 1 to 12, wherein the second resin layer is formed in a convex shape. The LED lighting device according to claim 5 or 6, wherein the refractive index of the third resin layer is smaller than the refractive index of the second resin layer and larger than the refractive index of air.   The LED lighting device according to any one of claims 1 to 14, wherein the LED element is disposed on an opening peripheral edge of the concave portion.

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