JP2010231967A - Light emitting body and luminaire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase temperature of a transparent resin and a phosphor mixed therein by increasing a current flowing in an LED bare chip. <P>SOLUTION: A light emitting body 1 includes a substrate 2 having insulation and heat conductivity, the LED bare chip 3 mounted on a surface 2a of the substrate 2 and emitting a light ranging from an ultraviolet ray to a blue light, a phosphor layer 4 out of contact with the LED bare chip 3, formed on the surface 2a of the substrate 2 around the LED bare chip 3, and converting a wavelength of an incident light emitted from the LED bare chip 3 into a predetermined light, and the transparent resin 5 mixed with light diffusing particles 19 and provided on the surface 2a of the substrate 2 so as to airtight seal the LED bare chip 3 and the phosphor layer 4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a light emitter that emits visible light by mixing different color lights, and a lighting fixture provided with the light emitter.

A wavelength conversion type light emitting diode that converts blue light emission into white is known (for example, see Patent Document 1). In this type of light emitting diode, for example, a concave portion is provided in a lead frame, and a blue light emitting LED bare chip is placed and fixed in the concave portion, and the concave portion is sealed with a transparent resin mixed with phosphor particles. And the white light is obtained by mixing the blue light emitted from the LED bare chip and the light in which a part of the blue light excites the phosphor particles and is wavelength-converted.

JP-A-7-99345 (page 2-3, Fig. 1)

In recent years, LED modules (light emitters) in which a large number of LED bare chips are mounted on a substrate have been used in lighting fixtures. Further, in order to increase the emitted light from the LED bare chip, the amount of current to be passed through the LED bare chip is increased. Thereby, the temperature of the LED bare chip rises, and the temperature of the phosphor mixed with the transparent resin sealing the LED bare chip also rises.

Furthermore, the phosphor has an increased light density due to an increase in the amount of light from the LED bare chip, and heat is generated by its own quantum efficiency and Stokes shift. Thereby, there existed a problem that the quantum efficiency of fluorescent substance fell and the thermal deterioration of transparent resin arose. In order to avoid this, it is conceivable to provide a phosphor layer directly on or around the LED bare chip, but an improvement in heat dissipation by contacting the LED bare chip can be expected, but the light density increases, Like the above, the problem was not solved.

An object of this invention is to provide the light-emitting body which has many LED bare chips which cannot raise the temperature of fluorescent substance easily even if it increases the electricity supply amount of a LED bare chip, and the lighting fixture which comprises this light-emitting body.

The invention of the light emitter according to claim 1 is a substrate having insulating properties and heat conductivity; an LED bare chip mounted on one surface side of the substrate and emitting light in a region of ultraviolet to blue light; and the LED bare chip A phosphor layer that is formed on one side of the substrate around the LED bare chip and converts the wavelength of incident radiation of the LED bare chip into predetermined light; and light diffusing particles are mixed; And a translucent resin provided on one side of the substrate so as to hermetically seal the LED bare chip and the phosphor layer.

In the present invention and the following inventions, each configuration is as follows unless otherwise specified.

The substrate can be formed of a metal such as aluminum (Al), for example. In the case of metal, an insulating layer having heat conductivity is formed on one surface of the substrate, and the LED bare chip is mounted. Further, the substrate can be formed of a ceramic plate or the like having an insulating property.

A plurality of LED bare chips may be regularly mounted such as a lattice shape or a concentric circle shape, or may be mounted in a random shape.

The phosphor layer converts the wavelength of light emitted from the LED bare chip into predetermined light, and becomes visible light when the wavelength-converted light is mixed (colored) with the light emitted from the LED bare chip. As described above, an appropriate type is selected according to the color tone of the visible light. For example, the LED bare chip emits blue light and the phosphor layer is formed with a YAG phosphor that converts the wavelength of blue light into yellow light, thereby emitting white light mixed with blue light and yellow light. Emitted from the body.

The phosphor layer may be formed around each LED bare chip, or may be formed so as to be continuous with the phosphor layer around the adjacent LED bare chip.

According to the present invention, the light emitted from the LED bare chip is transmitted through the translucent resin and emitted outward from the surface of the translucent resin, and a part thereof is mixed with the translucent resin. The light is reflected and diffused on the surface side of the light diffusing particles and the translucent resin, enters the phosphor layer, and is wavelength-converted to predetermined light by the phosphor layer. The wavelength-converted light is reflected on the substrate side, passes through the translucent resin, and is emitted outward from the surface of the translucent resin. Thereby, the visible light which mixed the light radiated | emitted from LED bare chip and the predetermined light wavelength-converted by the fluorescent substance layer is obtained.

And since the light reflected and diffused on the surface side of the light diffusing particles or the translucent resin is incident on the phosphor layer, the light density in the phosphor layer is reduced, and the heat generation density of the phosphor layer is reduced. Get smaller. Further, the heat generated in the phosphor layer is transferred to the substrate having heat transfer properties. Furthermore, the phosphor layer is not in contact with the LED bare chip and is not easily subjected to the heat generated by the LED bare chip. Thereby, the temperature rise of a fluorescent substance layer is suppressed and the fall of the quantum efficiency of a fluorescent substance layer and the thermal deterioration of a translucent resin are prevented.

The invention of a lighting fixture according to claim 2 is characterized by comprising: the light emitter according to claim 1; and a fixture body in which the light emitter is disposed.

According to this invention, the lighting fixture which can be illuminated with the visible light radiate | emitted from the light-emitting body of Claim 1 is provided.

According to the first aspect of the present invention, the phosphor layer reflects and diffuses the incident light from the LED bare chip, and its light density is reduced, heat is transferred to the one surface side of the substrate, and the LED bare chip. Since the temperature rise is suppressed by being non-contact with the LED, even if a large number of LED bare chips are mounted on the substrate and the amount of electricity supplied to the LED bare chips is increased, the quantum efficiency of the phosphor layer is reduced or the light transmission is increased. It is possible to prevent thermal degradation of the functional resin, thereby realizing improvement in luminous efficiency and long life of the luminous body.

According to the second aspect of the present invention, since the light emitting body with improved luminous efficiency and longer life is provided, the illuminated surface can be illuminated brightly, and the illumination efficiency is high and the illumination is improved. An instrument can be provided.

1 is a schematic cross-sectional view of a light emitter showing Example 1 of the present invention. Similarly, the partially expanded schematic top view of a light-emitting body. Similarly, the schematic top view of a light-emitting body. The partial notch schematic side view of the lighting fixture which shows Example 2 of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In the present invention, a phosphor layer for wavelength-converting light emitted from an LED bare chip is formed in a non-contact manner with the LED bare chip and formed on the substrate side around the LED bare chip. Then, the light emitted from the LED bare chip is reflected and diffused by the light diffusing particles mixed in the translucent resin to enter the phosphor layer, thereby reducing the light density in the phosphor layer, By transferring the generated heat to the substrate, the temperature rise of the phosphor layer is suppressed.

1 to 3 show a first embodiment of the present invention, FIG. 1 is a schematic sectional view of a light emitter, FIG. 2 is a partially enlarged schematic top view of the light emitter, and FIG. 3 is a schematic top view of the light emitter. .

In FIG. 1, the light emitter 1 includes a substrate 2, an LED bare chip 3, a phosphor layer 4, and a translucent resin 5.

The substrate 2 is made of, for example, an aluminum (Al) plate having a thickness of 1 mm, and an insulating layer 6 having a thickness of 80 μm is formed on one surface 2a thereof. The insulating layer 6 is made of, for example, an epoxy material and an inorganic filler material, and has high thermal conductivity. On the surface of the insulating layer 6, a copper foil pattern 7 that is electrically connected to the electrodes 10 and 11 of the LED bare chip 3 and electrically connects the LED bare chips 3 is formed. In addition, a copper foil (not shown) is provided on the surface of the insulating layer 6 on which the LED bare chip 3 is mounted. The copper foil is nickel (Ni) plated, and further silver (Ag) plated or gold (Au) plated. ing.

In the LED bare chip 3, a light emitting layer 9 is formed on the surface of a sapphire 8 formed in a rectangular parallelepiped shape, and electrodes 10 and 11 are provided on the surface of the light emitting layer 9. The sapphire 8 is bonded by transparent silicone (not shown) immediately above the silver plating layer or the gold plating layer. The electrodes 10 and 11 are connected to the copper foil patterns 7 and 7 by bonding wires 12 and 13. The light emitting layer 9 is formed with a light emitting material that emits light in a region from ultraviolet light to blue light. For example, the light emitting layer 9 includes InGaN, and emits blue light when energized.

As shown in FIG. 3, a plurality (large number) of LED bare chips 3 are mounted on the one surface 2 a side of the substrate 2 so as to have, for example, a lattice shape. On the insulating layer 6 formed on the one surface 2 a of the substrate 2, an insulating covering plate that is formed to have the same size as the substrate 2 and has a circular storage portion 14 and a substantially rectangular cutout portion 15. 16 is affixed. The covering plate 16 is made of, for example, a ceramic plate having a thickness of 4 mm. The LED bare chip 3 is mounted in a grid pattern on the one surface 2a side of the substrate 2 in the storage unit 14.

Further, terminals 17, 17 to which a lead wire is connected and DC power is supplied are provided on the surface 2 a side of the substrate 2 of the notch 15. The terminals 17 and 17 are connected to the copper foil patterns 7 and 7 and are electrically connected to the LED bare chip 3.

In FIG. 1, the phosphor layer 4 is made of a silicone resin containing a YAG phosphor that converts the wavelength of blue light into predetermined light such as yellow light. The phosphor layer 4 is formed on the insulating layer 6 on the side 2a of the substrate 2 around the LED bare chip 3 by printing. That is, as shown in FIG. 2, it is formed over the entire area of the insulating layer 6 in the storage portion 14 of the cover plate 16 except for the rectangular non-formed portion 18. Since the phosphor layer 4 is not in contact with the LED bare chip 3 by the non-forming portion 18, heat from the generated LED bare chip 3 is difficult to transfer.

As shown in FIG. 1, the translucent resin 5 is a mixture of translucent silicone resin and light diffusing particles 19 such as titanium oxide (TiO ₂ ). The LED bare chip 3 and the phosphor layer 4 are hermetically sealed on the one surface 2a side of the substrate 2. And the surface 5a of the translucent resin 5 is formed flat.

Next, the operation of the first embodiment of the present invention will be described.

When DC power is supplied to the terminals 17 and 17 of the light emitting body 1, the LED bare chip 3 generates heat and emits blue light from the light emitting layer 9. A part of the blue light passes through the translucent resin 5 and is emitted outward from the surface 5 a of the translucent resin 5. Further, part of the blue light is reflected and diffused by the light diffusing particles 19 mixed in the translucent resin 5, and is reflected and diffused on the surface 5 a side of the translucent resin 5. A part of the reflected and diffused blue light is incident on the phosphor layer 4 formed on the one surface 2 a side of the substrate 2.

The phosphor layer 4 converts the wavelength of incident blue light into yellow light. The yellow light is reflected on the surface 2 a of the substrate 2 toward the translucent resin 5, passes through the translucent resin 5, and is emitted outward from the surface 5 a of the translucent resin 5. Then, the blue light and the yellow light emitted from the surface 5a of the translucent resin 5 are mixed (colored) to obtain white light. That is, white light is emitted from the light emitter 1. Here, by providing a diffusion plate on the storage portion 14 of the covering plate 16, blue light and yellow light are more diffused and mixed, and white light with improved color unevenness is emitted from the light emitter 1. be able to.

Then, since the reflected and diffused blue light is incident on the phosphor layer 4, the light density in the phosphor layer 4 is reduced. As a result, the amount of heat generated when the wavelength of blue light is converted to yellow light is reduced, and the heat generation density of the phosphor layer 4 is reduced. Further, since the phosphor layer 4 is formed on the insulating layer 6 having high thermal conductivity on the one surface 2 a side of the substrate 2, the heat generated in the phosphor layer 4 is highly thermally conductive through the insulating layer 6. Heat is transferred to an aluminum (Al) substrate 2 having Furthermore, the phosphor layer 4 is not in contact with the LED bare chip 3 and is less likely to receive heat from the LED bare chip 3 that is generating heat. As a result, the energization amount of the LED bare chip 3 is increased, the heat generation of the LED bare chip 3 is increased, and even if the amount of blue light emitted from the LED bare chip 3 is increased, a large number of the LED bare chip 3 is formed on the surface 2a side of the substrate 2. Even if the LED bare chip 3 is mounted, the temperature rise of the phosphor layer 4 is suppressed, and thereby the quantum efficiency of the phosphor layer 4 can be prevented from being lowered.

Further, the translucent resin 5 generates heat by absorbing a part of each of blue light and yellow light that passes therethrough, and rises in temperature by receiving heat generated by the LED bare chip 3 and the phosphor layer 4. However, since the translucent resin 5 does not receive heat from the phosphor layer 4 as much as the temperature rise of the phosphor layer 4 is suppressed as described above, the temperature rise is suppressed. Therefore, thermal degradation of the translucent resin 5 can be prevented.

As described above, even when a large number of LED bare chips 3 are mounted on the substrate 2 and the amount of electricity supplied to the LED bare chips 3 is increased, a decrease in quantum efficiency of the phosphor layer 4 and a thermal deterioration of the translucent resin 5 are prevented. Therefore, the luminous efficiency of the luminous body 1 can be improved and the lifetime can be increased. In addition, since the number of LED bare chips 3 is increased and the amount of light emitted from each LED bare chip 3 is increased, the amount of light emitted from the light emitter 1 can be increased, and the irradiated surface is brightened. Can be illuminated.

FIG. 4 is a partially cutaway schematic side view of a lighting fixture showing Embodiment 2 of the present invention. The same parts as those in FIG.

  A lighting fixture 20 shown in FIG. 4 is a downlight embedded in a ceiling surface or the like, and a circular decorative frame 22 is provided on the lower end side of a substantially cylindrical fixture main body 21, and a transparent cover is provided on the decorative frame 22. 23 is arranged. And the instrument main body 21 has attached a pair of attachment springs 24 and 24 for fixing the instrument main body 21 to a ceiling surface etc. on both right and left sides.

  Moreover, the instrument main body 21 arrange | positions the four light-emitting bodies 1 shown in FIG. A power supply unit 25 is disposed inside the instrument body 21. The power supply unit 25 houses a power supply circuit and the like. The power circuit converts AC power into DC power and supplies a constant current to the LED bare chip 3 of the light emitter 1. A terminal block 26 for connecting a power line (not shown) from the AC power source is disposed on the upper surface side of the instrument main body 21.

The lighting fixture 20 includes a large number of LED bare chips 3 and includes four light emitting bodies 1 that have improved luminous efficiency and have a long life even when the amount of electricity supplied to the LED bare chips 3 is increased. It is possible to provide a lighting apparatus that can illuminate the irradiation surface brightly and has high illumination efficiency and improved reliability.

INDUSTRIAL APPLICABILITY The present invention can be used for general or industrial lighting fixtures, bulb-type appliances mounted on bulb sockets, LED bulbs, and the like.

DESCRIPTION OF SYMBOLS 1 ... Light-emitting body, 2 ... Board | substrate, 3 ... LED bare chip, 4 ... Phosphor layer, 5 ... Translucent resin, 20 ... Lighting fixture, 21 ... Instrument main body

Claims (2)

A substrate having insulating properties and heat conductivity; an LED bare chip mounted on one surface of the substrate and emitting light in a region from ultraviolet light to blue light; and non-contact with the LED bare chip; A phosphor layer that is formed on one side of the substrate and converts the wavelength of the incident emitted light of the LED bare chip into a predetermined light; and light diffusing particles are mixed to hermetically seal the LED bare chip and the phosphor layer And a translucent resin provided on the one surface side of the substrate. A lighting fixture comprising: the light emitter according to claim 1; and a fixture body on which the light emitter is disposed.

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