JP2011114093A - Lighting system - Google Patents

Abstract

Provided is an illuminating device that has less color unevenness of light emitted from a light exit surface of the illuminating device and higher light extraction efficiency.
Wavelengths covering a plurality of LED chips 1 via a plurality of LED chips (light emitting elements) 1 on one surface 2a of a mounting substrate 2 and a covering portion 4 covering the plurality of LED chips 1. The conversion layer 3, and the covering portion 4 has a first covering member 5 that covers the LED chip 1 and a refractive index higher than the first covering member 5 that covers the first covering member 5. Of the light emitted from the LED chip 1 between the adjacent LED chips 1 toward the adjacent LED chip 1 side. It is the illuminating device 10 provided with the interface which reflects light in the wavelength conversion layer 3 side facing the said one surface 2a between LED chips 1 by refraction of light.
[Selection] Figure 1

Description

  The present invention relates to a light emitting device and an illumination device using a wavelength conversion layer that converts the wavelength of light from the light emitting device.

  In recent years, a light-emitting element composed of a semiconductor light-emitting element such as an LED chip and a phosphor that covers the light-emitting element and absorbs at least part of the light from the light-emitting element and emits a complementary color by wavelength conversion are included. For example, a light-emitting device that emits white light in which blue light from a light-emitting element and yellow light from a wavelength conversion layer are mixed has been developed. This type of light-emitting device has been applied to lighting devices as the light output of light-emitting elements increases.

  When such a light-emitting device is applied to a lighting device, it is difficult to obtain a sufficient light output as a lighting device with only the light output of one light-emitting element. In order to obtain this, it is conceivable to mount a plurality of light emitting elements on a mounting substrate and to dispose a wavelength conversion layer so as to cover the plurality of light emitting elements. However, since the light emitting element is relatively small when viewed from the whole lighting device, and is regarded as a point light source, the individual light emission is simply achieved by arranging the wavelength conversion layer so as to cover a plurality of light emitting elements. The light emitted from the element is noticeable. For example, in a lighting device using a plurality of LED chips, which are a plurality of light emitting elements that emit blue light, and a wavelength conversion layer that absorbs blue light and emits yellow fluorescent light, the light emitting surface of the lighting device , The amount of light emitted from the lighting device differs between the position where the LED chips are arranged and the position between the LED chips. For this reason, the position of the light emitting surface of the illumination device between the LED chips becomes darker than the position where the LED chips are arranged. Further, on the light emitting surface of the illumination device, the color tone of the position corresponding to the LED chips tends to appear more yellow than the position corresponding to the LED chip. In particular, in order to obtain a desired light distribution, the lighting device may be separately combined with a lens or a reflecting mirror, and uneven illumination and uneven color are conspicuous on the irradiated surface irradiated with light from the lighting device. In some cases.

  By the way, in order to reduce the illuminance unevenness in the light emitted from the illuminating device using a plurality of LED chips, as shown in FIG. 5, the mounting substrate 2 and the mounting substrate 2 are separated and mounted on one surface. A plurality of LED chips 1 and a covering portion 4 ′ covering the plurality of LED chips 1, and the covering portion 4 ′ containing a powder 11 having a diffusion effect and a reflection effect An apparatus 10 'is known (for example, see Patent Document 1).

  In the illumination device 10 ′ shown in FIG. 5, a reflective layer 12 that reflects light from the LED chip 1 is formed on one surface side of the mounting substrate 2 on which the LED chip 1 is mounted. In addition, the illumination device 10 ′ is provided with a resistor 13 and the like used for limiting current to the LED chip 1 on the other surface side of the mounting substrate 2. 5, the light emitted from the LED chip 1 is isotropically emitted in all directions by the powder 11 in the covering portion 4 ′, and emits uniform planar light emission. Is supposed to be possible.

JP 2000-156525 A

  However, in the illumination device 10 ′ shown in FIG. 5 described above, the light emitted from the LED chip 1 is diffused and reflected by the powder 11 in the covering portion 4 ′, and is attenuated when the light is diffused or reflected. May end up. In addition, since the light emitted from the LED chip 1 is repeatedly diffused and reflected by the powder 11 in the covering portion 4 ′, the optical path length of the light until it is emitted outside the illumination device 10 ′ is increased. As a result, it is also attenuated by the covering portion 4 ′ and the like.

  As another method, it may be possible to reduce unevenness in color and luminance on the light exit surface of the illumination device by providing a diffusion plate that diffuses light on the light exit surface side of the illumination device. As in the case of 1, the light extraction efficiency decreases due to light scattering and absorption.

  Therefore, at the present time when higher light extraction efficiency is required with more uniform planar light emission, the above-described configuration of the illumination device 10 ′ is not sufficient and further improvement is required.

  The present invention has been made in view of the above-described reasons, and an object thereof is to provide a lighting device with less light color unevenness emitted from the light emitting surface of the lighting device and higher light extraction efficiency. is there.

  The invention of claim 1 includes a mounting substrate, a plurality of light emitting elements mounted on one surface of the mounting substrate so as to be spaced apart from each other, and a plurality of the light emitting elements through a covering portion that covers the plurality of light emitting elements. A wavelength conversion layer that covers a light emitting element and wavelength-converts at least a part of light emitted from the light emitting element, wherein the covering portion covers each of the light emitting elements. And a second covering member that covers the first covering member and has a refractive index larger than that of the first covering member, and the second covering member is disposed between the adjacent light emitting elements. The interface that reflects the light emitted from the light emitting element toward the adjacent light emitting element side to the wavelength conversion layer side facing the one surface between the light emitting elements by light refraction. It is characterized by comprising.

  According to this invention, the second covering member of the covering portion mounts the light emitted from the light emitting elements toward the adjacent light emitting element side between the light emitting elements by refraction of the light. Since it has an interface to be reflected on the wavelength conversion layer side facing one surface of the substrate, it is possible to provide a lighting device with less color unevenness of light emitted from the light emitting surface of the lighting device and higher light extraction efficiency. .

  In addition, since the interface of the second covering member of the lighting device can be formed by filling a coating material using a coating process for covering the light emitting element at the time of manufacturing, the lighting device can be manufactured relatively easily. This can also reduce the manufacturing cost of the lighting device.

  According to a second aspect of the present invention, in the first aspect of the invention, the second covering member is a third covering member that contacts the second covering member in a light emission direction along the thickness direction of the light emitting element. The third covering member has a refractive index smaller than that of the second covering member.

  According to this invention, the third covering member allows the part of the light in the light emission direction along the thickness direction of the light emitting element to be part of the wavelength conversion layer facing the one surface between the light emitting elements. Therefore, the color unevenness can be reduced and the light extraction efficiency can be increased.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the second covering member is formed on the second covering member facing the one surface between the light emitting elements. A fourth covering member is provided in contact with the second covering member via at least a part of the second covering member, and the fourth covering member has a refractive index larger than that of the second covering member. Features.

  According to this invention, among the light traveling toward the wavelength conversion layer facing the one surface between the light emitting elements, the light transmitted through the second covering member and reflected by the wavelength conversion layer is reflected. Further, since it can be reflected again to the wavelength conversion layer side at the interface between the second covering member and the fourth covering member, color unevenness can be further reduced and light extraction efficiency can be increased. .

  In the invention of claim 1, a first covering member that covers each of the plurality of light emitting elements, a second covering member that covers the first covering member and has a higher refractive index than the first covering member, And the second covering member emits light emitted from the light emitting elements among the adjacent light emitting elements toward the adjacent light emitting elements by refraction of light. By providing an interface that reflects to the wavelength conversion layer side facing the one surface of the mounting substrate on which the light emitting element is mounted between the elements, color unevenness of light emitted from the light emitting surface of the illumination device There is a remarkable effect that it is possible to provide a lighting device with less light extraction efficiency.

It is a schematic sectional drawing which shows the illuminating device of Embodiment 1. It is a schematic sectional drawing which shows another illuminating device same as the above. It is a schematic sectional drawing which shows the illuminating device of Embodiment 2. It is a schematic sectional drawing which shows the illuminating device of Embodiment 3. It is a schematic sectional drawing which shows the conventional illuminating device.

(Embodiment 1)
Hereinafter, the illuminating device of this embodiment is demonstrated based on FIG. 1 and FIG. In FIG. 1 and FIG. 2, the same members are denoted by the same reference numerals and redundant description is omitted.

  The illumination device 10 shown in FIG. 1 of the present embodiment includes a mounting substrate 2 and LED chips 1 that are a plurality of (three in this case) light emitting elements mounted separately on one surface 2a of the mounting substrate 2. And a wavelength conversion layer 3 that covers the plurality of LED chips 1 via the covering portion 4 that covers the plurality of LED chips 1 and converts the wavelength of at least a part of the light emitted from the LED chip 1. Have. Here, the covering portion 4 includes a first covering member 5 that covers the LED chip 1 and a second covering that covers the first covering member 5 and has a higher refractive index than the first covering member 5. 1, and the second covering member 6 is light that is directed toward the adjacent LED chip 1 among the light emitted from the LED chips 1 between the adjacent LED chips 1 (in FIG. 1). An interface that reflects the broken line arrow) to the wavelength conversion layer 3 side facing the one surface 2a between the LED chips 1 by refraction of light is provided.

  More specifically, the lighting device 10 uses, for example, a mounting substrate 2 in which a pair of conductor patterns (not shown) plated with Au is formed on a rectangular flat alumina ceramic substrate. The LED chip 1 mounted on the one surface 2a of the mounting substrate 2 includes an n-type gallium nitride compound semiconductor layer, a light emitting layer made of a gallium nitride compound semiconductor containing In, and a p-type on a sapphire substrate, respectively. Gallium nitride compound semiconductor layers are sequentially stacked. In the LED chip 1, a part of the p-type gallium nitride compound semiconductor layer and the light emitting layer are removed, and the n-type gallium nitride compound semiconductor layer is partially exposed. An anode electrode and a cathode electrode that are electrically connected to each of the n-type and n-type gallium nitride compound semiconductor layers are provided. The LED chip 1 includes a plurality of Au bumps (not shown) each provided with the anode electrode and the cathode electrode provided on the same plane side of the LED chip 1 on a pair of conductor patterns on the mounting substrate 2. ) And flip chip mounting so that power can be supplied.

  The plurality of LED chips 1 respectively mounted on the one surface 2a of the mounting substrate 2 emit light having a peak wavelength of blue light emitted by energization within a range of, for example, 450 nm to 470 nm.

  The covering portion 4 is a first covering member that is formed by a dimethyl-based silicone resin that covers the LED chip 1 and has a convex shape that is smoothly raised from the one surface 2a and has a refractive index of about 1.41. 5 and a second covering member 6 formed of a phenyl silicone resin having a refractive index of about 1.5, which is higher than that of the first covering member 5. One main surface side (the lower side in FIG. 1) of the second covering member 6 is disposed between the plurality of recesses 6 a that individually accommodate the first covering member 5 and the LED chips 1. The other main surface side (upper side in FIG. 1) of the 2nd coating | coated member 6 is equipped with the smooth smooth part 6c. In the illumination device 10 of the present embodiment, among the light emitted from the LED chips 1 between the adjacent LED chips 1, the light directed toward the adjacent LED chips 1 is converted into the LED chips 1 by refraction of light. The interface of the second covering member 6 to be reflected to the wavelength conversion layer 3 side facing the one surface 2a in between is the convex surface of the second covering member 6 smoothly raised from the one surface 2a. .

Further, the wavelength conversion layer 3 is made of a yellow phosphor (for example, Y ₃ Al ₅ O ₁₂ activated by Ce) that can absorb yellow light emitted from the LED chip 1 and emit yellow fluorescence. The film is uniformly dispersed in a phenyl silicone resin, and the outer shape is formed in a film shape having a thickness of about 200 μm that can be disposed on the second covering member 6. The wavelength conversion layer 3 is adhered to the smooth smooth portion 6c of the second covering member 6 with a translucent adhesive.

  By the way, in the illuminating device 10 of this embodiment shown in FIG. 1, the blue light radiated | emitted from the LED chip 1 to the adjacent LED chip 1 side permeate | transmits the 1st coating | coated member 5, and is convex of the 2nd coating | coated member 6. It enters the part 6b. The blue light incident on the second covering member 6 covers the adjacent LED chip 1 by refraction of the light and has a lower refractive index than the second covering member 6, and the second covering member. The light is totally reflected at the interface with the member 6 and radiated to the outside of the illumination device 10 through the wavelength conversion layer 3. Therefore, in the illumination device 10 of the present embodiment, light is emitted not only from the position where the LED chip 1 is disposed but also from the position between the adjacent LED chips 1 on the light emission surface of the illumination device 10. It becomes possible to suppress that the emitted light intensity of the illuminating device 10 becomes weak between LED chip 1 to perform. In addition, the reflection at the interface of the second covering member 6 using the refraction of light does not completely reflect all the light emitted from the adjacent LED chips 1 like a mirror. Moreover, the uniformity of the light output radiated | emitted from the illuminating device 10 can be improved more as the illuminating device 10 whole.

  That is, as illustrated in FIG. 1, the illumination device 10 according to the present embodiment is configured to receive light (refer to broken arrows in FIG. 1) toward the adjacent LED chip 1 among the light emitted from the LED chips 1. , Is incident on the second covering member 6, passes through the second covering member 6, and is totally reflected at the interface between the second covering member 6 and the first covering member 5 covering the adjacent LED chip 1. It is configured to do. In other words, of the light emitted from the LED chip 1 at the interface of the second covering member 6 of the lighting device 10, the light directed toward the adjacent LED chip 1 side (see the broken arrow in FIG. 1) is the LED chip. 1 is reflected in a direction approaching the optical axis (here, the normal direction on the upper surface of the LED chip 1). In order to cause such total reflection due to light refraction, the second covering member 6 forms the light and a tangential perpendicular to the surface of the second covering member 6 on which the light is irradiated. What is necessary is just to design so that an angle may become more than a critical angle.

  Hereinafter, each structure used for the illuminating device 10 of this embodiment is explained in full detail.

  The light emitting element used in the illumination device 10 of the first embodiment is a semiconductor element that can emit light when energized. The light emitted from the light-emitting element can be, for example, blue light having a peak wavelength in the range of 450 nm to 470 nm of visible light, but is not limited to blue light. Ultraviolet light may be used to excite the wavelength conversion layer 3 efficiently. As the LED chip 1 which is a light emitting element, for example, an n-type gallium nitride compound semiconductor layer, a multiple quantum well structure or the like is formed on a crystal growth substrate such as a sapphire substrate, a spinel substrate, a gallium nitride substrate, a zinc oxide substrate or a silicon carbide substrate. For example, a gallium nitride compound body layer containing indium and a p-type gallium nitride compound semiconductor layer, which are light emitting layers having a single quantum well structure, are sequentially stacked. Such an LED chip 1 can be formed with a size of about 1 mm square and a thickness of about 100 μm.

  The LED chip 1 using an insulating substrate is exposed to the anode electrode on the same plane side by exposing a part of the n-type gallium nitride compound semiconductor layer from the p-type gallium nitride semiconductor layer side. And a cathode electrode can be formed respectively. The LED chip 1 using a conductive substrate may be formed with an anode electrode and a cathode electrode on both sides in the thickness direction of the LED chip 1.

  The anode electrode or the cathode electrode provided on the LED chip 1 is a material that can obtain good ohmic characteristics with a laminated film of a Ni film and an Au film, a gallium nitride compound semiconductor layer such as an Al film, an ITO film, or the like. It is not limited.

  The LED chip 1 provided with the anode electrode and the cathode electrode on the same plane side has a pair of conductive patterns on the mounting substrate 2 such as Au bumps having a diameter of 0.07 mm and a height of 0.05 mm. Flip chip mounting can be performed using metal bumps. When the LED chip 1 having the anode electrode or the cathode electrode formed on both sides in the thickness direction is used as the LED chip 1, a pair of conductors formed on the mounting substrate 2 on which the LED chip 1 is mounted. One conductor pattern of the patterns and the anode electrode or the cathode electrode of the LED chip 1 are electrically connected by die bonding or the like via a conductive member (for example, AuSn or Ag paste). The other cathode electrode or anode electrode on the light extraction surface side of the LED chip 1 may be electrically connected to the other conductor pattern via a wire (for example, a gold wire or an aluminum wire).

  When the LED chip 1 has a double hetero structure in which a light emitting layer made of a gallium nitride compound semiconductor layer containing indium is sandwiched between clad layers made of gallium nitride, aluminum nitride, aluminum gallium nitride or the like, the light emitting layer From the difference in refractive index between the materials of the cladding layer and the clad layer, much light is emitted from the end face of the light emitting layer, which greatly contributes to the effect of the illumination device 10 of the present embodiment.

  In the illumination device 10 shown in FIG. 1 of the present embodiment, three LED chips 1 are mounted on the one surface 2a of the mounting substrate 2, but the number of LED chips 1 is limited to this. It can be increased or decreased as appropriate. In this case, each LED chip 1 may be electrically connected appropriately in series, parallel, or series-parallel using the conductor pattern of the mounting substrate 2. Moreover, the LED chip 1 may use the same kind, and may use the some LED chip 1 which light-emits the light of a different light emission wavelength.

  Next, the mounting substrate 2 used in the lighting device 10 of the present embodiment can mount the LED chip 1 as a light emitting element. In addition, the mounting substrate 2 may constitute an energization path of the LED chip 1 by using the pair of conductor patterns (for example, a conductor pattern plated with Au on the outermost surface) on the mounting substrate 2. As such a mounting substrate 2, a ceramic substrate using alumina, aluminum nitride, or the like, a metal base substrate using a metal material such as Cu, Al, or Fe, a glass epoxy resin substrate, or the like can be used. When an alumina ceramic substrate is used as the mounting substrate 2, the heat conductivity is higher than that of a glass epoxy resin substrate or the like, and the heat generated by lighting the LED chip 1 is efficiently radiated to the outside so that the heat dissipation of the lighting device 10 is achieved. Can be increased.

  The mounting substrate 2 of the lighting device 10 of the present embodiment is formed in a rectangular flat plate shape having a size of about 5 mm square and a thickness of about 0.3 mm, but the outer periphery of the one surface 2a of the mounting substrate 2 In order to make it easy to radiate the light radiated | emitted from LED1 outside to a part, you may provide a side wall (not shown) separately. Since the side wall has a tapered portion that spreads outward from the one surface 2a of the mounting substrate 2, light can be easily extracted to the outside of the lighting device 10, and light extraction efficiency of the lighting device 10 can be improved. . Further, the mounting substrate 2 may be provided with a reflective layer that reflects light on the side wall.

Further, the lighting device 10 may be provided with a reflecting portion (not shown) on the one surface 2a of the mounting substrate 2, and such a reflecting portion efficiently reflects light emitted from the LED chip 1. Specifically, a metal material such as Al, Al alloy, Ag, or Ag alloy or a glass material containing an inorganic material that becomes a white pigment such as BaSO ₄ may be used. . In addition, when the said reflection part has electroconductivity, the illuminating device 10 is between the said reflection part and the said pair of conductor pattern so that each said anode electrode and said cathode electrode of LED chip 1 may not short-circuit. An insulating layer (not shown) may be formed as appropriate.

  The mounting substrate 2 may be configured as an external electrode of the lighting device 10 by extending a conductor pattern from the one surface 2 a of the mounting substrate 2 to the side surface and the back surface. Such external electrodes of the illumination device 10 can be electrically connected to a wiring board (not shown) by a reflow process or the like.

  The wavelength conversion layer 3 used in the present embodiment absorbs at least a part of the light emitted by the LED chips 1 as a plurality of light emitting elements and converts the wavelength, so that the wavelength conversion layer 3 is longer wavelength than the light from the LED chip 1 It emits fluorescence which is the main emission wavelength.

  For example, the wavelength conversion layer 3 absorbs part of the light emitted from the LED chip 1 and emits a fluorescent material that emits fluorescence having a main emission wavelength on a longer wavelength side, such as a silicone resin, an acrylic resin, an epoxy resin, or the like. What is necessary is just to include and form in translucent materials, such as glass. As a material of the wavelength conversion layer 3 containing the phosphor, preferably, a translucent material having a refractive index equal to or larger than that of the second covering member 6 is used. When a silicone resin is used as the material, a preferable example of the material of the wavelength conversion layer 3 containing the phosphor is a phenyl silicone resin.

  Further, the thickness of the wavelength conversion layer 3 varies depending on the target color temperature of the light emitted from the illumination device 10, the emission intensity of the blue light emitted from the LED chip 1, the luminous efficiency of the phosphor, etc. The phosphor can be formed to a thickness of about 200 μm with a concentration of 50% by weight or less.

When the LED chip 1 that emits blue light is provided and white light is emitted from the illumination device 10, the phosphor contained in the wavelength conversion layer 3 is not limited to the complementary yellow phosphor, and for example, the illumination device 10. Therefore, in order to emit white light having higher color rendering properties, a green phosphor capable of emitting green light (for example, (Sr, Ba) ₂ SiO ₄ activated by Eu) is emitted from the LED chip 1 in blue. A red phosphor capable of absorbing light and emitting red light (for example, CaAlSiN ₃ activated with Eu) can also be used. Therefore, as the phosphor used in the wavelength conversion layer 3, which is activated by activated with _Ba 2 SiO ₄ and Eu in Eu (Sr, _Ba) 2, such as SiO ₄ rare earth doped with the silicate Besides phosphors, for example, aluminate phosphors doped with rare earth such as Y ₃ Al ₅ O ₁₂ activated with Ce and Tb ₃ Al ₅ O ₁₂ activated with Ce, activated with Eu CaSi ₇ which is activated with been CaAlSiN _{3, Sr} is activated by Eu 2 _Si 5 _N 8, _Ca were activated by Eu 2 _Si 5 _N 8, Eu in-activated the SrSi ₇ N ₁₀ and Eu phosphor of the rare earth in doped a nitride, such as N ₁₀ to may be properly adopted.

  The covering portion 4 used in the present embodiment has translucency, and includes a first covering member 5 that covers at least the LED chip 1 that is a light emitting element, and a first covering member 5 that covers the first covering member 5. And a second covering member 6 having a refractive index larger than that of the covering member 5.

  The first covering member 5 used in the present embodiment is a translucent member that enhances the effect of taking out the light emitted inside the LED chip 1 that is a light emitting element to the outside of the LED chip 1. It is to be coated. Examples of the material of the first covering member 5 include a dimethyl silicone resin having a refractive index of 1.41. The shape of the 1st coating | coated member 5 can be made into the convex shape which protruded smoothly from the said one surface 2a, for example. The first covering member 5 may be provided in a plural number so as to cover each of the plurality of LED chips 1, or may be a single unit that covers the plurality of LED chips 1.

  Next, the second covering member 6 used in the present embodiment is a second covering member 6 by refraction of the light emitted from the LED chip 1 toward the adjacent LED chip 1 side by light refraction. And the first covering member 5 that passes through the second covering member 6 and covers the adjacent LED chip 1 from the second covering member 6, and the above-mentioned one between the LED chips 1. It has an interface for reflection on the wavelength conversion layer 3 side facing the surface 2a.

  As the material of the second covering member 6, a light-transmitting material having a higher refractive index than that of the first covering member 5 is used, for example, a phenyl silicone resin having a refractive index of about 1.5. It is done. When the second covering member 6 uses a dimethyl silicone resin having a refractive index of 1.41 for the first covering member 5 in addition to the phenyl silicone resin having a refractive index of about 1.5, A resin, glass, or the like having a refractive index greater than 1.41 can be used as appropriate. The shape of the second covering member 6 is such that one main surface side (the lower side in FIG. 1) is, for example, between the recess 6 a that houses the first covering member 5 and the LED chips 1. The other main surface side (the upper side in FIG. 1) has a plate shape including a smoothing portion 6 c so that the wavelength conversion layer 3 can be disposed. The second covering member 6 is more preferably subjected to a light shielding treatment with, for example, an Ag film in order to eliminate unnecessary light leakage from the end face of the peripheral portion of the second covering member 6. .

  In the illumination device 10 of the present embodiment, each LED chip 1 is covered with a first covering member 5, and each LED chip 1 and the first covering member 5 are covered with a second covering member 6. In the illumination device 10, the refractive index of the first covering member 5 is made smaller than the refractive index of the second covering member 6. The first covering member 5 is in contact with the second covering member 6, and preferably the first covering member 5 covers the second covering member 6.

  Such 1st coating | coated member 5 and 2nd coating | coated member 6 coat | cover each LED chip 1, and can use suitably the translucent material with high translucency in a visible region. Specific materials of the first covering member 5 and the second covering member 6 include silicone resin, acrylic resin, epoxy resin, glass, and the like, and a material having a refractive index suitable for the part to be used. What is necessary is just to employ | adopt suitably. For example, the epoxy resin can have a refractive index of 1.55 to 1.61, and the silicone resin can have a refractive index of 1.35 to 1.53.

  When a silicone resin is used as the first covering member 5 and the second covering member 6, a phenyl type silicone resin is used as the first covering member 5, and a fluorine type silicone resin is used as the second covering member 6. By using it, the refractive index of the first covering member 5 can be made higher than the refractive index of the second covering member 6.

  In addition, the illuminating device 10 of this embodiment provides the air layer 7 between the 1st coating | coated member 5 which covers the LED chip 1, and the 2nd coating | coated member 6 like the illuminating device 10 shown in FIG. Also good. In this case, the illuminating device 10 has a difference in refractive index between the second covering member 6 and the air layer 7 as compared with a configuration in which the second covering member 6 and the first covering member 5 are in contact with each other. growing. Therefore, the illuminating device 10 increases the total reflection component at the interface between the second covering member 6 and the air layer 7 and can further reduce color unevenness.

  Moreover, the interface of the 2nd coating | coated member 6 of the illuminating device 10 may be formed in the same shape with respect to each LED chip 1, respectively, and may be formed in a respectively different shape. That is, when a plurality of LED chips 1 are densely packed, the angle of the interface may be set so as to suppress the light that reflects the light from the LED chip 1. Similarly, the LED chips 1 of the lighting device 10 do not necessarily have to be arranged on the mounting substrate 2 at equal intervals, and are arranged at an appropriate distance depending on the light emission output of the LED chip 1 and the shape of the second covering member 6. be able to.

  Furthermore, the shape of the second covering member 6 may be set as appropriate according to the angle of light emitted from the adjacent LED chip 1, and has an inclination angle that reflects light not only on a smooth curve but also on the wavelength conversion layer 3 side. It may be formed in a stepped shape.

  Next, the manufacturing process of the illuminating device 10 shown in FIG. 1 of this embodiment is demonstrated.

  First, a plurality of LED chips 1 are flip-chip mounted using Au bumps on a conductor pattern formed on the one surface 2a of the mounting substrate 2 in consideration of necessary light flux, heat dissipation, and the like.

  Further, the second covering member 6 of the lighting device 10 has a flat plate shape, and a plurality of recesses capable of accommodating a plurality of LED chips flip-chip mounted on the mounting substrate 2 on one main surface side. 6a is formed, and the other main surface side is molded by injecting a phenyl-type silicone resin in advance into a mold and heat-curing so that a smooth portion 6c that becomes a smooth surface can be formed. The second covering member 6 is a mounting substrate 2 on which the LED chip 1 is mounted in advance after filling a plurality of recesses 6 a of the second covering member 6 with a dimethyl-based silicone resin that becomes the first covering member 5. And the first covering member 5 is heat-cured.

  In addition, a plate-shaped wavelength conversion layer 3 in which a yellow phosphor capable of absorbing blue light and emitting yellow fluorescence is contained in a silicone resin is separately molded with a mold. The illuminating device 10 can be formed by affixing the wavelength conversion layer 3 on the smooth part 6c of the second covering member 6 using a translucent adhesive.

  As a result, the lighting device 10 covers the second covering member 6 in contact with the first covering member 5. The shape of the interface between the first covering member 5 and the second covering member 6 can be changed relatively easily depending on the mold shape when the second covering member 6 is formed. The wavelength conversion layer 3 is not only formed in advance and attached to the second covering member 6 but also a transparent material containing a phosphor on the second covering member 6 by using a screen printing method or an ink jet printing method. It can also be formed by applying a light material.

  Furthermore, as another forming method of the lighting device 10 of the present embodiment, the first covering member 5 and the second covering member 6 are each flipped each LED chip 1 on the one surface 2a of the mounting substrate 2, for example. After mounting the chip, first, a dimethyl silicone resin material to be the first covering member 5 is filled so as to surround the LED chip 1 and is heated and cured to form a convex shape. Next, the second covering member 6 covers the entirety of the plurality of LED chips 1 each covered with the first covering member 5 with a phenyl-based silicone resin material to be the second covering member 6. Thus, it can also be formed by coating on the mounting substrate 2 and heat curing. In addition, the shape of the interface between the first covering member 5 and the second covering member 6 can be adjusted by adjusting the viscosity of the translucent material to be the first covering member 5 when the first covering member 5 is formed. Can be changed relatively easily.

  In the illumination device 10 of the present embodiment formed in this way, even when the light emission surface is viewed, the amount of light emitted from the illumination device 10 is between the position where the LED chip 1 is disposed and between the LED chips 1. Therefore, the light output difference is reduced, and the color unevenness is reduced. As a result, the illuminating device 10 can reduce unevenness in the color of the irradiated surface of the light emitted from the illuminating device 10 even when a lens or a reflecting mirror is disposed on the light emitting surface side of the wavelength conversion layer 3. it can. In addition, the lighting device 10 according to the present embodiment does not have to mix powder of a diffusing material or a reflecting material in order to reduce color unevenness. Therefore, the light by the light absorption of the powder 11 having the diffusion effect and the reflection effect is compared with the above-described lighting device 10 ′ in which the light diffusion property is enhanced by the powder 11 having the diffusion effect and the reflection effect. A decrease in extraction efficiency can be suppressed, and diffusibility and the like can be improved. Note that the lighting device 10 of the present embodiment has a smaller usage amount than the above-described lighting device 10 ′ even if the powder 11 having a diffusion effect or a reflection effect is mixed with the covering portion 4. Unevenness can be reduced.

(Embodiment 2)
In this embodiment, instead of the second covering member 6 of the first embodiment shown in FIG. 1, the second covering member 6 is arranged in the light emission direction along the thickness direction of the LED chip 1 as shown in FIG. 3. The difference is that a second covering member 6 provided with a third covering member 8 having a smaller refractive index is used. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted suitably.

  The third covering member 8 provided on the second covering member 6 of the lighting device 10 of the present embodiment proceeds in the light emission direction along the thickness direction of the LED chip 1 out of the light emitted from the LED chip 1. The blue light is refracted at the interface between the third covering member 8 and the second covering member 6 and blue light is emitted to the wavelength conversion member 3 side facing the one surface 2a between the LED chips 1. Can guide you. Thereby, the illuminating device 10 has less color unevenness on the light emitting surface of the illuminating device 10, and can improve the light extraction efficiency.

  Examples of the material of the third covering member 8 include the first covering member 5 using a dimethyl silicone resin having a refractive index of about 1.41, and a refractive index of about 1.5. A silicone resin having an intermediate refractive index with respect to the second covering member 6 using a phenyl-based silicone resin is preferably exemplified, and is larger than the refractive index of the first covering member 5 and larger than that of the second covering member 6. Resins or glass having a small refractive index can be preferably used.

  The illuminating device 10 of this embodiment mounts a plurality of LED chips 1 on the mounting substrate 2 in consideration of necessary light flux, heat dissipation, and the like. Next, the second covering member 6 made of phenyl silicone resin is formed into a predetermined shape with a mold. The third covering member 8 is formed by filling and curing a silicone resin as a material of the third covering member 8 so as to fill a part of the bottom of the plurality of recesses 6a of the second covering member 6. To do. Subsequently, the second covering member 6 is formed by applying a dimethyl silicone resin as a material of the first covering member 5 on the third covering member 8 inside the recessed portion 6a of the second covering member 6. Fill until full. A third covering member 8 is formed at the bottom of the recess 6a of the second covering member 6, and the second covering member 6 in which the resin serving as the material of the first covering member 5 is filled in the recess 6a is connected to the LED. The chip 1 is bonded to the mounting substrate 2 on which the chip 1 is mounted, and is cured by heating. Then, the illuminating device 10 of this embodiment can be formed by sticking the wavelength conversion layer 3 previously shape | molded with the metal mold | die on the 2nd coating | coated member 6 with a translucent adhesive agent.

  In the illumination device 10 of the present embodiment, blue light emitted from the LED chip 1 and directed toward the adjacent LED chip 1 is radiated to the outside in the same manner as the illumination device 10 of the first embodiment. Further, when the blue light in the light emission direction along the thickness direction of the LED chip 1 is incident on the second covering member 6 from the third covering member 8, the third covering member 8 and the second covering member are used. 6 is partly refracted toward the wavelength conversion layer 3 facing the one surface 2 a between the LED chips 1. Thereby, the illuminating device 10 sees a light-projection surface, and the color nonuniformity etc. of the position where the LED chip 1 is arrange | positioned, and the position between LED chips 1 are reduced more.

(Embodiment 3)
In the present embodiment, in addition to the configuration of the second covering member 6 of the lighting device 10 of the first embodiment, as shown in FIG. 4, the second covering member facing the one surface 2 a between the LED chips 1. 6 is provided with a fourth covering member 9 in contact with the second covering member 6 through at least a part of the second covering member 6, and the refractive index of the fourth covering member 9 is set to the second covering member 9. The difference is that it is larger than the refractive index of the covering member 6. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted suitably.

  As a specific configuration example of the second covering member 6 shown in FIG. 4 used in the lighting device 10 of the present embodiment, the other main surface side in the second covering member 6 of Embodiment 2 shown in FIG. (Upper side in FIG. 3) Instead of constituting the entire smoothing portion 6c, the second facing the surface 2a of the mounting substrate 2 between the plurality of LED chips 1 shown by the illumination device 10 in FIG. A recess 6d is provided on the other main surface side (upper side in FIG. 4) of the cover member 6, and a fourth cover member 9 having a higher refractive index than the second cover member 6 is provided inside the recess 6d. Configuration.

  Thereby, the illuminating device 10 of this embodiment sees a light-projection surface, among the light from the LED chip 1 which goes to the wavelength conversion layer 3 facing the said one surface 2a between several LED chips 1 mutually. The light reflected by the wavelength conversion layer 3 can be reflected again at the interface between the fourth covering member 9 and the second covering member 6.

  As the material of the fourth covering member 9, a resin or glass having a refractive index higher than that of the second covering member 6 is conceivable. For example, PMMA (polyethylene having a refractive index of about 1.55) (Methyl methacrylate resin) can be preferably used.

  The other main surface of the second covering member 6 has a recess 6d filled with the fourth covering member 9 to be a smooth surface. The illumination device 10 may be formed by adhering the wavelength conversion layer 3 with a translucent adhesive on the other main surface of the second covering member 6.

  In addition, as a material of the wavelength conversion layer 3 containing the phosphor, the second coating member 6 or the fourth coating member 9 in contact with the wavelength conversion layer 3 has a refractive index equal to or higher than that, for example, a phenyl type Silicone resin, acrylic resin, glass and the like can be suitably used.

  More specifically, the lighting device 10 of the present embodiment flip-chip mounts a plurality of LED chips 1 on the mounting substrate 2 in consideration of necessary light flux, heat dissipation, and the like. Subsequently, the material of the third covering member 8 is filled in the bottom of the concave portion 6a on the one main surface of the second covering member 6 formed by injection molding with a mold in advance and is cured by heating. Similarly, the material of the fourth covering member 9 is filled in the inside of the recess 6d on the other main surface side of the second covering member 6 and is cured by heating.

  Subsequently, the second covering member 6 and the mounting substrate 2 on which the LED chip 1 is mounted are filled in the recess 6a of the second covering member 6 with the resin as the material of the first covering member 5 being filled. Bond and heat cure. Alternatively, the lighting device 10 can be formed by attaching the molded wavelength conversion layer 3 on the second covering member 6 with a translucent adhesive.

  Note that the recess 6 a and the recess 6 d of the second covering member 6 may be formed simultaneously with the molding of the second covering member 6, or a light-transmitting flat plate that becomes the second covering member 6 is drilled. For example, it may be formed by partial removal by performing excavation, etching, or laser irradiation.

  The illuminating device 10 of this embodiment is the fourth of the blue light of the LED chip 1 incident from the fourth covering member 9 on the side of the wavelength conversion layer 3 facing the one surface 2a between the LED chips 1. When the blue light reflected at the interface between the covering member 9 and the wavelength conversion layer 3 is incident on the second covering member 6 from the fourth covering member 9 at a critical angle or more, the fourth covering member 9 and the second covering member 9 Total reflection is caused by the difference in refractive index from the covering member 6. As a result, the illumination device 10 of the present embodiment has less uneven color of the light emitted from the light exit surface of the illumination device 10 by the fourth covering member 9, and can further increase the light extraction efficiency. Become.

1 LED chip (light emitting device)
2 mounting substrate 2a one surface 3 wavelength conversion layer 4 covering portion 5 first covering member 6 second covering member 8 third covering member 9 fourth covering member 10 illuminating device

Claims (3)

  A plurality of light-emitting elements that are mounted on a surface of the mounting board, and a plurality of light-emitting elements that cover the plurality of light-emitting elements; A wavelength conversion layer that wavelength-converts at least a part of light emitted from the element, wherein the covering section includes a first covering member that covers each of the light emitting elements, and the first covering member. A second covering member that covers the covering member and has a higher refractive index than the first covering member, and the second covering member is radiated from the light emitting elements between the adjacent light emitting elements. The light is directed to the adjacent light emitting element side, and is reflected by the refraction of the light to the wavelength conversion layer side facing the one surface between the light emitting elements. A lighting device.   The second covering member is provided with a third covering member in contact with the second covering member in a light emission direction along the thickness direction of the light emitting element, and the third covering member is provided with the second covering member. The illumination device according to claim 1, wherein the refractive index is smaller than that of the covering member. The second covering member is in contact with the second covering member through at least a part of the second covering member to the second covering member facing the one surface between the light emitting elements. The lighting device according to claim 1, wherein four covering members are provided, and the fourth covering member has a refractive index higher than that of the second covering member.

Images