JP2007116116A - Light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting device in which emission efficiency can be enhanced while optimizing the thickness of a resin layer containing phosphor and the amount of combination of phosphor. <P>SOLUTION: An LED (Light Emitting Diode) lamp 1 has an LED chip 2 as a light emitting element in a cavity 3. The LED chip 2 is sealed with a resin layer 9 containing phosphor having a thickness of 400-800 μm. The resin layer 9 containing phosphor contains transparent resin and 5-20 wt.% of phosphor for the transparent resin. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

  LED lamps using light emitting diodes (LEDs) are rapidly expanding in various fields such as backlights for liquid crystal displays, mobile phones, information terminals, indoor / outdoor advertisements, and the like. In addition, LED lamps have long life and high reliability, and have features such as low power consumption, impact resistance, high-purity display color, and lightness and thinness. Application is also being attempted. When such an LED lamp is applied to various applications, it is important to obtain white light emission.

  Typical methods for realizing white light emission with LED lamps are (1) a method using three LED chips that emit blue, green, and red colors, and (2) a blue light emitting LED chip between yellow and orange. There are three methods: combining the phosphor that emits the light of (3), combining the LED chip that emits ultraviolet light and the three-color mixed phosphor of blue, green, and red (hereinafter referred to as RGB phosphor). Can be mentioned. Of these, the method (2) is generally widely used. In addition, it is reported that the luminous efficiency of 8.2 lm / W and average color rendering index Ra86 to 90 were obtained by the method (3). Further, in the method (2), an increase in the average color rendering index Ra is expected by using a red light emitting phosphor in addition to a phosphor emitting light between yellow light and orange light.

  As the structure of the LED lamp to which the above methods (2) and (3) are applied, for example, a transparent resin mixed with a phosphor is poured into a cup-shaped frame equipped with an LED chip, and this is solidified to phosphor. The structure etc. which formed the fluorescent substance containing resin layer containing are proposed (for example, refer patent document 1). In addition, a structure in which a transparent resin mixed with a phosphor is formed into a sheet shape, which is fixed to a frame on which an LED chip is disposed, for example, and a phosphor-containing resin layer containing the phosphor is formed has been proposed. . In such LED lamps, improvement of light extraction efficiency based on the electrode shape of the LED chip such as a flip chip, and light distribution control by examining the chip shape are promoted, and the amount of light to the front surface of the chip increases. There is a tendency.

  As the amount of light to the front surface of the chip increases, the thickness (optical path length) of the phosphor-containing resin layer described above affects the light extraction efficiency. Generally, as shown in FIG. 5, it is known that the luminous efficiency of an LED lamp is improved by controlling the thickness of the phosphor-containing resin layer within a predetermined range.

In this way, the luminous efficiency of the LED lamp is further improved by controlling the thickness of the phosphor-containing resin layer and adjusting the blending amount of the phosphor contained according to the thickness of the phosphor-containing resin layer. It is known that For example, when the thickness of the phosphor-containing resin layer is thin, the amount of phosphor blended with the transparent resin is increased. When the thickness of the phosphor-containing resin layer is thick, the blending amount of the phosphor with respect to the transparent resin Is adjusted slightly.
JP 2001-148516 A

  However, in the LED lamp having the conventional phosphor-containing resin layer as described above, optimization of the thickness of the phosphor-containing resin layer and the blending amount of the phosphor is not sufficient. For example, in the case of a thin phosphor-containing resin layer of about 200 μm, when the phosphor is blended by about 30% by weight with respect to the transparent resin, the intergranularity of the phosphor contained in the phosphor-containing resin layer becomes narrow, It becomes difficult for light emitted from the LED chip to pass through between the grains. Therefore, the light emission efficiency of the LED lamp is based on the light emitted from the LED chip passing through the phosphor particles in the phosphor-containing resin layer and the light emission of the phosphor itself excited by the light from the LED chip. There was a tendency to cause a decline. Furthermore, the desired color temperature could not be obtained.

  An object of the present invention is to provide a light emitting device capable of improving the luminous efficiency and adjusting the color temperature while optimizing the thickness of the phosphor-containing resin layer and the blending amount of the contained phosphor. There is to do.

  The light-emitting device according to claim 1 includes a light-emitting element; a transparent resin and 5 to 20% by weight of a phosphor with respect to the transparent resin, and a thickness of 400 to 800 μm arranged to cover the light-emitting element. And a phosphor-containing resin layer.

  The light-emitting device according to claim 2 is a substrate having a recess; a light-emitting element disposed in the recess; a transparent resin layer disposed so as to cover the light-emitting element; a transparent resin and the transparent resin And a sheet-like phosphor-containing resin layer having a thickness of 300 to 800 μm, which is disposed so as to cover the concave portion of the base material. Yes.

  The light-emitting device according to claim 3 is the light-emitting device according to claim 1 or 2, wherein the light-emitting element has a light-emitting diode chip that emits blue light, and the phosphor emits from the light-emitting diode chip. It is characterized by having a yellow phosphor that emits light between yellow-green light and orange light when excited by the blue light emitted.

  The light-emitting device according to claim 4 has a light-emitting element that emits blue light; a yellow phosphor having an average particle diameter of 10 to 20 μm and a transparent resin, and a blending ratio of the phosphor when the film thickness is 400 to 500 μm. The blending ratio of the phosphor when the film thickness is 500 to 600 μm is 12.0 to 15.0 wt% with respect to the transparent resin. The blending ratio of the phosphor when the film thickness is 600 to 700 μm is 10.0 to 12.0 wt% with respect to the transparent resin, and the blending ratio of the phosphor when the film thickness is 700 to 800 μm is the above-described ratio. It is 7.5 to 10.0% by weight with respect to the transparent resin, and is configured such that the blue color from the light emitting element and the yellow color from the phosphor are mixed to have a color temperature of 2850K (Kelvin) or more and less than 5000K. A phosphor-containing resin layer; It is characterized by that.

  The light-emitting device according to claim 5 has a light-emitting element that emits blue light; a yellow-based phosphor having an average particle diameter of 10 to 20 μm and a transparent resin, and a blending ratio of the phosphor when the film thickness is 400 to 500 μm. It is 12.0-15.0 weight% with respect to the said transparent resin, and the compounding ratio of the said fluorescent substance when the film thickness is 500-600 micrometers is 10.0-12.0 weight% with respect to the said transparent resin. The blending ratio of the phosphor when the film thickness is 600 to 700 μm is 7.5 to 10.0% by weight with respect to the transparent resin, and the blending ratio of the phosphor when the film thickness is 700 to 800 μm is the above-mentioned. It is 6.5 to 7.5% by weight with respect to the transparent resin, and is configured such that the blue color from the light emitting element and the yellow color from the phosphor are mixed to have a color temperature of 5000 K (Kelvin) to 10,000 K. A phosphor-containing resin layer; It is characterized by.

  In the above-described inventions according to claims 1 to 5, the definitions and technical meanings of terms are as follows unless otherwise specified.

  The light emitting element emits visible light by exciting a phosphor with emitted light. Examples of the light emitting element used in the present invention include a blue light emitting type LED chip and an ultraviolet light emitting type LED chip. However, the light-emitting element is not limited thereto, and various light-emitting elements can be used depending on the use of the light-emitting device, the target light emission color, or the like as long as the light-emitting element can excite the phosphor and emit visible light. Can be used.

  The phosphor is excited by light emitted from the light emitting element to emit visible light, and is emitted by a color mixture of visible light emitted from the phosphor and light emitted from the light emitting element or from the phosphor. A desired light-emitting color is obtained as a light-emitting device by color mixing of visible light or visible light itself. The type of the phosphor is not particularly limited, and is appropriately selected according to the intended emission color, light emitted from the light emitting element, and the like.

  The phosphor-containing resin layer holds the phosphor. The phosphor-containing resin layer is formed by mixing a transparent resin and 5 to 20% by weight of a phosphor, which is the optimum blending ratio with respect to the transparent resin, and coating the light-emitting element to solidify it. As the transparent resin, for example, various liquid transparent resins such as an epoxy resin and a silicone resin can be applied. The phosphor-containing resin layer preferably has a thickness (optical path length) of 400 to 800 μm in order to improve luminous efficiency.

  Moreover, in this invention, you may apply the sheet-like fluorescent substance containing resin layer which shape | molded the transparent resin which added and mixed the fluorescent substance in the sheet form. Below, the structure of the light-emitting device of this invention to which the sheet-like fluorescent substance containing resin layer is applied is demonstrated. In the concave portion of the base material, a light emitting element, a transparent resin layer covering the light emitting element, and a sheet-like phosphor-containing resin layer are provided in this order from the bottom to the top.

  The base material is composed of, for example, a substrate having a wiring portion such as a circuit pattern or a lead terminal, and a frame that is provided on the substrate and forms a recess that opens to the outside. In addition, you may form a base material by forming a recessed part on a board | substrate, without using a flame | frame.

  A transparent resin layer seals the light emitting element in a recessed part, for example, is formed by filling transparent resin, such as an epoxy resin, into a recessed part using a dispenser etc. The transparent resin layer is provided with a sheet-like phosphor-containing resin layer in close contact with the upper end thereof.

  The sheet-like phosphor-containing resin layer holds the phosphor, is formed by mixing a transparent resin and 5 to 20% by weight of a phosphor, which is the optimum blending ratio with respect to the transparent resin, to form a sheet. It arrange | positions so that the recessed part of material may be coat | covered. The sheet-like phosphor-containing resin layer preferably has a thickness (optical path length) of 300 to 800 μm in order to improve luminous efficiency.

  According to the light emitting device of claim 1, the optimum blending ratio of the phosphor is set to 5 to 20% by weight with respect to the transparent resin, and the thickness of the phosphor-containing resin layer is controlled to 400 to 800 μm. A light-emitting device capable of improving the light emission efficiency can be provided.

  According to the light emitting device of claim 2, the optimum blending ratio of the phosphor is set to 5 to 20% by weight with respect to the transparent resin, and the thickness of the phosphor-containing resin layer is controlled to 300 to 800 μm. A light-emitting device that exhibits excellent luminous efficiency can be provided.

  According to the light emitting device of the third aspect, a so-called light bulb colored light emitting device can be provided.

  According to the light-emitting device according to claim 4, in the light-emitting device including the above-described blue light-emitting element and the phosphor-containing resin layer having a yellow fluorescent material having an average particle diameter of 10 to 20 μm and a transparent resin as described above, The content of the yellow phosphor in the body-containing resin layer and the thickness of the phosphor-containing resin layer are appropriately controlled, and the two are appropriately balanced. Therefore, the light bulb color from 2850K to less than 5000K is warm white White light can be obtained.

  According to the light-emitting device of claim 5, in the light-emitting device including the blue light-emitting element described above and the phosphor-containing resin layer having a yellow fluorescent material having an average particle diameter of 10 to 20 μm and a transparent resin as described above, Since the content of the yellow phosphor in the body-containing resin layer and the thickness of the phosphor-containing resin layer are appropriately controlled to balance them appropriately, white light of daylight with a color temperature of 5000K to 10000K is used. Can be obtained.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 is a cross-sectional view showing a configuration of a first embodiment in which the light-emitting device of the present invention is applied to an LED lamp. FIG. 2 is a diagram of the LED lamp shown in FIG. FIG. 3 is a cross-sectional view taken along line AA of FIG. 2.

  The LED lamp 1 shown in FIGS. 1 to 3 has an LED chip 2 as a light emitting element. As the LED chip 2, for example, a blue light emitting type LED chip, an ultraviolet light emitting type LED chip, or the like is used. This LED chip 2 is mounted on a circuit pattern 8 provided on a substrate 5 with an electrical insulating layer 4 interposed therebetween.

  On the substrate 5, there is provided a frame 6 that forms a cavity 3 (concave portion) that opens upward in a truncated cone shape. The LED chip 2 is disposed in the cavity 3. A cavity 3 in which the LED chip 2 is disposed is filled with a phosphor-containing resin layer 9 made of a transparent resin containing a phosphor, and the LED chip 2 is sealed with the phosphor-containing resin layer 9. Yes. As the transparent resin, for example, a liquid transparent resin such as a silicone resin or an epoxy resin is preferable. The electrical energy applied to the LED lamp 1 is converted into blue light or ultraviolet light by the LED chip 2, and the light is converted into light having a longer wavelength by the phosphor contained in the phosphor-containing resin layer 9. The Then, a color based on the color of light emitted from the LED chip 2 and the emission color of the phosphor, for example, white light, is emitted from the LED lamp 1.

  The phosphor-containing resin layer 9 described above, for obtaining a desired amount of light from the LED lamp 1, is, for example, 5 to 20% by weight, preferably 10 to 15% by weight of the phosphor added to a transparent resin such as a silicone resin. After mixing, the cavity 3 in which the LED chip 2 is arranged is filled by using a dispenser or the like, and is thermally cured. At this time, the resin viscosity of the transparent resin is preferably in the range of 0.1 to 10 Pa · s at 25 ° C. in order to suppress entrainment of bubbles and the like. Accordingly, the bubble density in the phosphor-containing resin 9 containing the transparent resin can be reduced, and the irregular reflection of the generated light can be prevented, so that a light emitting device that exhibits excellent luminous efficiency is provided. Can do.

  The phosphor-containing resin layer 9 thus formed has a thickness of 400 to 800 μm, preferably 500 to 600 μm. When the amount of the phosphor is less than 400 μm, a sufficient amount of the phosphor to obtain a desired light amount is blended, so that the intergranularity of the phosphor becomes narrow in the phosphor-containing resin layer 9. Therefore, it becomes difficult for the light emitted from the LED chip 2 to pass through the phosphor-containing resin layer 9, and the light emitted from the LED chip 2 and the light emission of the phosphor itself in the resin layer 9 that is excited by this light and emits light. Therefore, it becomes difficult to obtain a desired light amount based on the above, and the luminous efficiency of the LED lamp 1 is reduced. On the other hand, if it exceeds 800 μm, the light emitted from the LED chip 2 does not reach the upper part of the phosphor-containing resin layer 9 (for example, the white light emission side), and the phosphor in the phosphor-containing resin layer 9 is sufficiently excited. It becomes difficult to obtain a desired light amount.

  In addition, it is preferable to use the fluorescent substance particle whose average particle diameter is the range of 10-20 micrometers. When the average particle size is less than 10 μm, the luminous efficiency of the phosphor particles decreases, and the luminous efficiency of the LED lamp 1 is reduced. On the other hand, when the average particle diameter exceeds 20 μm, the phosphor particles settle in the resin layer 9. In addition, the nozzle of the dispenser used when filling the resin layer 9 into the cavity 3 frequently clogs, which may reduce the yield. The average particle diameter can be controlled, for example, by performing a classification process such as sieving in the manufacturing process.

  In addition, even if classified to an average particle size of 10 to 20 μm, there are actually those having a particle diameter of less than 10 μm or exceeding 20 μm. This is because some particles are crushed or bonded by moisture after classification. Accordingly, when the particles are classified into an average particle size of 10 to 20 μm, it is sufficient that about 70% or more of the whole is in the range of 10 to 20 μm by number or weight.

  The phosphor contained in the phosphor-containing resin layer 9 emits visible light when excited by light emitted from the LED chip 2, for example, blue light or ultraviolet light. The phosphor-containing resin layer 9 functions as a light emitting portion, and is disposed in front of the LED chip 2 in the light emitting direction. The kind of the phosphor is appropriately selected according to the light emission color of the target LED lamp 1 and is not particularly limited.

For example, when the white light emission is obtained using the blue light emitting type LED chip 2, a yellow phosphor that emits light between yellow light and orange light is mainly used. Further, in order to improve the color rendering properties and the like, a red light emitting phosphor may be used in addition to the yellow phosphor. As the yellow phosphor that emits light between yellow light and orange light, for example, RE ₃ (Al, Ga) ₅ O ₁₂ : Ce phosphor (RE represents at least one selected from Y, Gd, and La). Silicate phosphors and oxide phosphors such as YAG phosphors such as AE ₂ SiO ₄ : Eu phosphors (AE is an alkaline earth element such as Sr, Ba, and Ca. The same shall apply hereinafter) It is done.

In the case where white light emission is obtained using the ultraviolet light emitting type LED chip 2, RGB phosphors are mainly used. Examples of blue light emitting phosphors include halophosphate phosphors such as AE ₁₀ (PO ₄ ) ₆ Cl ₁₂ : Eu phosphor and aluminate phosphors such as (Ba, Mg) Al ₁₀ O ₁₇ : Eu phosphor. The body is used. As the green light emitting phosphor, an aluminate phosphor such as a (Ba, Mg) Al ₁₀ O ₁₇ : Eu, Mn phosphor is used. As the red light emitting phosphor, an oxysulfide phosphor such as La ₂ O ₂ S: Eu phosphor is used.

Further, in place of the above-described phosphor, a nitride-based phosphor (for example, AE ₂ Si ₅ N ₈ : Eu) or an oxynitride-based phosphor (for example, Y ₂ ) capable of obtaining various emission colors depending on the composition. Si ₃ O ₃ N ₄ : Ce), a sialon-based phosphor (for example, AEx (Si, Al) ₁₂ (N, O) ₁₆ : Eu), or the like may be applied. The LED lamp 1 is not limited to the white light emitting lamp, and the LED lamp 1 having a light emitting color other than white can be configured. When the LED lamp 1 emits light other than white, for example, light of an intermediate color, various phosphors are appropriately used depending on the target light emission color.

  Therefore, according to the present embodiment, the optimum blending ratio of the phosphors in the phosphor-containing resin layer 9 is set to 5 to 20% by weight, and the thickness of the phosphor-containing resin layer 9 is easily in the range of 400 to 800 μm. By making it controllable, the luminous efficiency of the LED lamp 1 can be improved.

  In addition, when using the blue light emission type LED chip 2 and using the phosphor resin layer 9 containing a yellow phosphor as the phosphor, the blending of the phosphor when the film thickness of the resin layer 9 is 400 to 500 μm The ratio is 15.0 to 17.0% by weight with respect to the transparent resin constituting the resin layer 9, and the blending ratio of the phosphor when the film thickness is 500 to 600 μm is 12.0 to 15 with respect to the transparent resin. 0.05% by weight, the blending ratio of the phosphor when the film thickness is 600 to 700 μm is 10.0 to 12.0% by weight with respect to the transparent resin, and the phosphor has a film thickness of 700 to 800 μm. If the blending ratio is 7.5 to 10.0% by weight with respect to the transparent resin, the blue color from the LED chip 2 and the yellow color from the phosphor are mixed, and the light bulb color having a color temperature of 2850K or more and less than 5000K is heated. Can get white white light .

  Further, when the blue light emitting type LED chip 2 is used and the phosphor resin layer 9 containing a yellow phosphor is used as the phosphor, the blending of the phosphor when the resin layer 9 has a film thickness of 400 to 500 μm. The ratio is 12.0 to 15.0% by weight with respect to the transparent resin, and the blending ratio of the phosphor when the film thickness is 500 to 600 μm is 10.0 to 12.0% by weight with respect to the transparent resin. The blending ratio of the phosphor when the film thickness is 600 to 700 μm is 7.5 to 10.0% by weight with respect to the transparent resin, and the blending ratio of the phosphor when the film thickness is 700 to 800 μm is the transparent. If it is made into 6.5 to 7.5 weight% with respect to resin, the blue color from LED chip 2 and the yellow color from the said fluorescent substance will be mixed, and the white light of daylight with a color temperature of 5000 K or more and 10000 K or less will be obtained. it can.

  In the present embodiment, the flat type SMD type LED lamp 1 has been described as an example. However, the present invention is not particularly limited, and can be applied to, for example, a bullet type (or round type) LED lamp. Further, although the light emitting diode module 21 in which a plurality of LED lamps 1 are arranged in a matrix has been described, the present invention is not limited to this, and for example, the plurality of LED lamps 1 may be formed in one row. Furthermore, each of the LED lamps 1 may be singular.

(Second Embodiment)
Next, a second embodiment in which the light emitting device of the present invention is applied to an LED lamp will be described with reference to FIG. FIG. 4 is a cross-sectional view showing a configuration of a second embodiment in which the light emitting device of the present invention is applied to an LED lamp. The LED lamp 31 according to the second embodiment includes a transparent resin layer 32 that seals the LED chip 2 in the cavity 3, and a phosphor sheet 33 that is fixed to the frame 6 so as to be in close contact with the upper end of the transparent resin layer 32. This is different from the first embodiment described above. In addition, the same code | symbol is attached | subjected to the component same as the structure of the light-emitting device concerning 1st Embodiment, and the description is simplified or abbreviate | omitted.

  In the LED lamp 31 of the second embodiment, the cavity 3 in which the LED chip 2 is disposed is filled with a transparent resin layer 32 such as a silicone resin, and the LED chip 2 is sealed with the transparent resin layer 32. ing. The electrical energy applied to the LED lamp 31 is converted into, for example, blue light or ultraviolet light by the LED chip 2, and the light passes through the transparent resin layer 32 and is a phosphor contained in the phosphor sheet 33. It is converted into longer wavelength light. Then, a color based on the color of light emitted from the LED chip 2 and the emission color of the phosphor, for example, white light, is emitted from the LED lamp 31.

  The transparent resin layer 32 described above is formed, for example, by filling a liquid transparent resin such as a silicone resin or an epoxy resin into the cavity 3 in which the LED chip 2 is disposed using a dispenser or the like, and thermosetting. At this time, in order to suppress entrainment of bubbles and the like, the resin viscosity is preferably in the range of 0.1 to 10 Pa · s at 25 ° C. In addition, since the refractive index of the LED chip 2 and the refractive index of air differ, the transparent resin layer 32 is filled in order to improve light extraction efficiency.

  In the opening of the cavity 3, the phosphor sheet 33 is fixed to the frame 6 in a state of being in close contact with the upper end of the transparent resin layer 32 by, for example, adhesion, hermetic sealing, pressure bonding, or the like. In order to obtain a desired light amount of the LED lamp 31, the phosphor sheet 33 is added to and mixed with 5 to 20% by weight, preferably 10 to 15% by weight of a phosphor with respect to a transparent resin such as a silicone resin. It is formed by curing at 150 ° C. for 1 hour by a doctor blade method or the like. In addition, when bubbles are mixed when the transparent resin and the phosphor are mixed, it is preferable to remove the bubbles by vacuum degassing.

  The thickness of the phosphor sheet 33 thus formed is preferably about 300 to 800 μm, and preferably about 400 to 600 μm. When the thickness of the phosphor sheet 33 is less than 300 μm, it becomes difficult to contain a sufficient amount of phosphor to obtain a desired light amount. That is, when a sufficient amount of phosphor is blended to obtain a desired amount of light, the intergranularity of the phosphor in the phosphor sheet 33 is narrowed, and for example, blue light emitted from the LED chip 2 causes the phosphor sheet 33 to pass through the phosphor sheet 33. It becomes difficult to pass. Therefore, it becomes difficult to obtain a desired light quantity based on the light emitted from the LED chip 2 and the light emission of the phosphor itself in the phosphor sheet 33 excited and emitted by this light, and the light emission efficiency of the LED lamp 31 is reduced. Invite. On the other hand, if it exceeds 800 μm, for example, blue light emitted from the LED chip 2 does not reach the upper part of the phosphor sheet 33 (for example, the white light emission side), and it becomes difficult to sufficiently excite the phosphor in the phosphor sheet 33. It becomes difficult to obtain a desired light amount. In order to improve the luminous efficiency of the LED lamp 31, it is preferable to use phosphor particles having an average particle size in the range of 10 to 15 μm.

  Therefore, according to the present embodiment, the optimum blending ratio of the phosphors in the phosphor sheet 33 is set to 10 to 15% by weight, and the thickness of the phosphor sheet 33 can be easily controlled in the range of 300 to 800 μm. By doing so, the luminous efficiency of the LED lamp 31 can be improved.

(Third embodiment)
6 and 7 show a light emitting device for forming an LED package according to the third embodiment of the present invention. 6 is a plan view of the light emitting device, and FIG. 7 is a longitudinal sectional view of the light emitting device shown in FIG. 6 taken along line F2. 6 and 7 relating to the present embodiment, the same reference numerals are used for the same constituent elements as those in the drawings relating to the above-described embodiment.

  The light emitting device 1 shown in FIGS. 6 and 7 includes a package substrate such as a device substrate 5, a reflective layer 41, a circuit pattern 8, a plurality of preferably LED chips such as a semiconductor light emitting element 2, an adhesive layer 42, and a reflector 44. And a phosphor-containing resin layer 9 and a light diffusing member 43. In this example, the phosphor-containing resin layer 9 also functions as a sealing member.

  The device substrate 5 is made of a flat plate made of a metal or an insulating material such as a synthetic resin, and has a predetermined shape such as a rectangular shape in order to obtain a light emitting area required for the light emitting device 1. When the device substrate 5 is made of a synthetic resin, it can be formed of, for example, an epoxy resin containing glass powder. When the device substrate 5 is made of metal, the heat radiation from the back surface of the device substrate 5 is improved, the temperature of each part of the device substrate 5 can be made uniform, and the semiconductor light emitting element 2 that emits light in the same wavelength range. The variation in the emission color can be suppressed. In addition, as a metal material which has such an effect, the material excellent in the thermal conductivity of 10 W / m * K or more, specifically aluminum, or its alloy can be illustrated.

  The reflective layer 41 is sized so that a predetermined number of semiconductor light emitting elements 2 can be disposed, and is, for example, attached to the entire surface of the device substrate 5. The reflective layer 41 can be made of a white insulating material having a reflectance of 85% or more in a wavelength region of 400 nm to 740 nm. As such a white insulating material, a prepreg made of an adhesive sheet can be used. Such a prepreg can be formed by impregnating a sheet base material with a thermosetting resin mixed with a white powder such as aluminum oxide. The reflective layer 41 is bonded to one surface which becomes the surface of the device substrate 5 by its own adhesiveness.

  The circuit pattern 8 is bonded to the surface of the reflective layer 41 opposite to the surface to which the device substrate 5 is bonded as an energization element to each semiconductor light emitting element 2. For example, in order to connect the respective semiconductor light emitting elements 2 in series, the circuit pattern 8 is formed in two rows interspersed at predetermined intervals in the longitudinal direction of the device substrate 5 and the reflective layer 41 as shown in FIG. Yes. The end side circuit pattern 8a located on one end side of one circuit pattern 8 row is formed integrally with a power feeding pattern portion 8c, and similarly, the end side located on one end side of the other circuit pattern 8 row. The circuit pattern 8a is integrally formed with a power feeding pattern portion 8d.

  The power feeding pattern portions 8 c and 8 d are provided side by side at one end in the longitudinal direction of the reflective layer 41, and are separated from each other and insulated by the reflective layer 41. Electric wires (not shown) reaching the power supply are individually connected to the power supply pattern portions 8c and 8d by soldering or the like.

  The circuit pattern 8 is formed by the procedure described below. First, a reflective layer 41 made of a prepreg impregnated with the uncured thermosetting resin is pasted on the device substrate 5, and then a copper foil of the same size is pasted on the reflective layer 41. Next, the laminated body thus obtained is heated and pressurized to cure the thermosetting resin, whereby the device substrate 5 and the copper foil are pressed against the reflective layer 41 to complete the adhesion. Next, a resist layer is provided on the copper foil, and after etching the copper foil, the remaining resist layer is removed to form the circuit pattern 8. The thickness of the circuit pattern 8 made of copper foil is, for example, 35 μm.

  Each semiconductor light emitting element 2 is composed of, for example, a double-wire LED chip using a nitride semiconductor, and is formed by laminating a semiconductor light emitting layer 2a on one surface of an element substrate 2b having translucency as shown in FIG. ing. The element substrate 2b is made of, for example, a sapphire substrate. The element substrate 2b is thicker than the circuit pattern 8, for example, 90 μm.

  The semiconductor light emitting layer 2a is formed by sequentially stacking a buffer layer, an n-type semiconductor layer, a light emitting layer, a p-type cladding layer, and a P-type semiconductor layer on the main surface of the element substrate 2b. The light emitting layer has a quantum well structure in which barrier layers and tungsten layers are alternately stacked. An n-side electrode is provided on the n-type semiconductor layer, and a p-side electrode is also provided on the p-type semiconductor layer. This semiconductor light emitting layer 2a does not have a reflective film, and can emit light in both thickness directions.

  As shown in FIG. 7, each semiconductor light emitting element 2 is arranged between circuit patterns 8 adjacent to each other in the longitudinal direction of the device substrate 5, and is adhered to the same surface of the white reflective layer 41 by an adhesive layer 42. . Specifically, the other surface parallel to one surface of the element substrate 2 b on which the semiconductor light emitting layer 2 a is laminated is bonded to the reflective layer 41 by the adhesive layer 42. By this adhesion, the circuit pattern 8 and the semiconductor light emitting element 2 are arranged in a straight line on the same surface of the reflective layer 41, so that the side surface of the semiconductor light emitting element 2 positioned in this arrangement direction and the circuit pattern 8 face each other closely. It is provided to do.

  The thickness of the adhesive layer 42 can be, for example, 5 μm or less. For the adhesive layer 42, for example, a translucent adhesive having a thickness of 5 μm or less and a light transmittance of 70% or more, such as a silicone resin adhesive, can be suitably used.

  As shown in FIGS. 6 and 7, the electrode of each semiconductor light emitting element 2 and the circuit pattern 8 disposed in proximity to both sides of the semiconductor light emitting element 2 are connected by a bonding wire 7 provided by wire bonding. Further, the end-side circuit patterns 8b positioned on the other end side of the two rows of circuit patterns 8 are also connected by bonding wires 7 (see FIG. 6) provided by wire bonding. Therefore, in the case of this embodiment, each semiconductor light emitting element 2 is connected in series.

  The surface emitting source of the light emitting device 1 is formed by the device substrate 5, the reflective layer 41, the circuit pattern 8, each semiconductor light emitting element 2, the adhesive layer 42, and the bonding wire 7.

  The reflector 44 is not individually provided for each one or several semiconductor light emitting elements 2 but is a single one that surrounds all the semiconductor light emitting elements 2 on the reflective layer 41 and has a frame, for example, FIG. The semiconductor light emitting element 2 is disposed in a recess 21 formed by the frame. The reflector 44 is bonded to the reflective layer 41, and a plurality of semiconductor light emitting elements 2 and circuit patterns 8 are housed therein, and the pair of power feeding pattern portions 8 c and 8 d are positioned outside the reflector 44. ing.

  The reflector 44 can be formed of, for example, a synthetic resin, and its inner peripheral surface is a reflective surface. The reflecting surface of the reflector 44 can be formed by depositing or plating a metal material having a high reflectance such as Al or Ni, or by applying a white paint having a high visible light reflectance. Alternatively, white powder can be mixed into the molding material of the reflector 44 to make the reflector 44 itself white with high visible light reflectance. As the white powder, a white filler such as aluminum oxide, titanium oxide, magnesium oxide or barium sulfate can be used. In addition, it is desirable to form the reflecting surface of the reflector 44 so as to gradually open in the irradiation direction of the light emitting device 1.

  The phosphor-containing resin layer 9 is composed of a yellow phosphor and a transparent resin containing the yellow phosphor, and each semiconductor light-emitting element 2 and bonding in which a liquid transparent resin is arranged on the reflective layer 41 surface and in a straight line. The wires 7 and the like are filled evenly and are solidified in the reflector 44. The liquid transparent resin flowing between the surface of the reflective layer 41 and the bonding wire 7 reaches each semiconductor light emitting element 2 and the bonding wire 7 due to a capillary phenomenon or the like, and the film thickness thereof is almost uniform. It is considered that the yellow phosphor is almost uniformly dispersed in the transparent resin. The viscosity of the liquid transparent resin used for forming the phosphor-containing resin layer 9 may be 1 Pa · S or more and 3 Pa · S or less, and may be composed of two or more liquid transparent resins. Therefore, in this embodiment, the color temperature can be adjusted after optimizing the thickness of the phosphor-containing resin layer 9 and the blending amount of the phosphor, and further, there is reflection from the reflective layer 41, so that the light emission efficiency Will improve.

Next, examples of the present invention and evaluation results thereof will be described.
(Examples 1 and 2)
Example 1 was applied to the phosphor-containing resin layer 9 of the LED lamp 1 having the configuration shown in FIG. First, 10% by weight of an orange phosphor (phosphor 1) is added to a silicone resin, mixed, filled into a cavity with a dispenser, and then the silicone resin is cured to form a phosphor-containing resin layer 9. Then, the LED lamp 1 having the configuration shown in FIG. 1 was produced. At this time, the thickness of the phosphor-containing resin layer 9 was changed between 400 μm and 1000 μm.

  On the other hand, in Example 2, instead of the orange phosphor used in Example 1 above, 10% by weight of a yellow phosphor (phosphor 2) was added and mixed, filled in the cavity with a dispenser, and then a silicone resin. Was cured to form a phosphor-containing resin layer 9, and the LED lamp 1 having the structure shown in FIG. 1 was produced. At this time, the thickness of the phosphor-containing resin layer 9 was changed between 400 μm and 1000 μm.

  The relationship between the thickness of the phosphor resin layer 9 and the color temperature and efficiency ratio of the LED lamp 1 in Examples 1 and 2 is shown in Table 1 and FIGS.

  As is apparent from Table 1 and FIGS. 8 and 9, in both phosphors 1 and 2, the thickness of the phosphor-containing resin layer 9 is in the range of 400 μm to 800 μm, which is the range of the present invention. It can be seen that a high efficiency ratio of around 1 is exhibited within the range of the color temperature as light.

  In FIG. 9, the peak value of the efficiency ratio of the phosphor 1 is in the range of about 400 μm to 600 μm, while the peak value of the efficiency ratio of the phosphor 2 is in the range of about 800 μm to 1000 μm. This can be explained as follows.

  The phosphor 1 has a dominant wavelength in the vicinity of about 580 nm, and the amount of emitted light increases as the content of the phosphor 1 increases as the thickness of the resin layer 9 increases. However, when the content of the phosphor 1 increases to a predetermined amount or more, the amount of light extracted from the package to the outside decreases. Therefore, the peak value of the efficiency ratio of the phosphor 1 is in the range where the thickness of the resin layer 9 is about 400 μm to 600 μm. On the other hand, since the phosphor 2 has a dominant wavelength in the vicinity of about 560 nm, even when the content of the phosphor 2 increases as the thickness of the resin layer 9 increases, the phosphor 2 is taken out from the package described above. The decrease in the amount of light does not occur particularly in the range of the present embodiment. Therefore, the peak value of the efficiency ratio of the phosphor 2 is such that the thickness of the resin layer 9 is in the range of about 800 μm to 1000 μm.

  In addition, when the thickness of the phosphor-containing resin layer 9 is smaller than 400 μm, the color temperature rises and is no longer in the range of white light. Further, the upper end of the wire may protrude from the upper surface of the application.

  Based on the results of Examples 1 and 2 described above, in the following Examples and Comparative Examples, the thickness of the phosphor-containing resin layer 9 is set so that the color temperature obtainable from the LED lamp 1 is about 5000K. The blending amount of the phosphor and the phosphor was adjusted.

(Examples 3-5, Comparative Examples 1-2)
In Example 3, the phosphor-containing resin layer 9 is formed by adding 15% by weight of the yellow phosphor to the silicone resin, mixing, filling the cavity with a dispenser, and then curing the silicone resin, An LED lamp 1 having the configuration shown in FIG. 1 was produced. The thickness of the phosphor-containing resin layer 9 was 400 μm.

  Similarly, Example 4 is a phosphor-containing resin layer having a thickness of 600 μm in which the amount of yellow phosphor added to the silicone resin is 10% by weight, and Example 5 has an amount of yellow phosphor added to the silicone resin. A phosphor-containing resin layer having a thickness of 800 μm, which is 7.5% by weight, Comparative Example 1 is a phosphor-containing resin layer having a thickness of 200 μm, in which the amount of yellow phosphor added to the silicone resin is 30% by weight, Comparative Example In No. 2, a phosphor-containing resin layer having a thickness of 1000 μm in which the addition amount of the yellow phosphor with respect to the silicone resin was 6% by weight was applied, and LED lamps were respectively produced. In each of these LED lamps, the luminous efficiency was examined. The measurement results are shown in Table 2. The luminous efficiency of the LED lamp is a relative value when Example 4 is set to 1.

  As is clear from Table 2, the LED lamps of the respective examples to which the phosphor-containing resin layer having a thickness of 400 to 800 μm in which the addition amount of the yellow phosphor with respect to the silicone resin is 5 to 20% by weight are applied have luminous efficiency. Can be seen to improve.

(Examples 6-8, Comparative Examples 3-4)
Example 6 was applied to the phosphor sheet 33 of the LED lamp 31 having the configuration shown in FIG. First, the LED chip 2 was sealed by filling the cavity with a silicone resin using a dispenser. Next, 18% by weight of a yellow phosphor was added to and mixed with the silicone resin, formed into a sheet having a thickness of 400 μm by the doctor blade method, and cured at 150 ° C. for 1 hour to form a phosphor sheet 33. . An LED lamp 31 shown in FIG. 4 was produced by fixing the phosphor sheet 33 so as to cover the cavity 3.

  Similarly, Example 7 is a phosphor sheet with a thickness of 600 μm in which the addition amount of the yellow phosphor to the silicone resin is 12% by weight, and Example 8 is an addition amount of the yellow phosphor to the silicone resin of 9% by weight. % Phosphor sheet with a thickness of 800 μm, Comparative Example 3 is a phosphor sheet with a thickness of 200 μm and the amount of yellow phosphor added to the silicone resin is 36% by weight, and Comparative Example 4 is a yellow system with respect to the silicone resin. An LED lamp was fabricated by applying a phosphor sheet having a thickness of 1000 μm with an added amount of phosphor of 7% by weight. In each of these LED lamps, the luminous efficiency was examined. The measurement results are shown in Table 2. The luminous efficiency of the LED lamp is a relative value when Example 5 is 1.

  As is clear from Table 3, the LED lamps of the respective examples to which the phosphor sheet having a thickness of 400 to 600 μm in which the addition amount of the yellow phosphor to the silicone resin is 12 to 18% by weight are excellent in luminous efficiency. It can be seen that

(Examples 9 to 12)
In the present embodiment, the blue light emitting LED chip 1 is used, and a phosphor-containing resin layer 9 containing a yellow phosphor (phosphor 2) is used. The phosphor 2 content and thickness in the resin layer 9 are used. By adjusting and balancing them appropriately, an attempt was made to obtain white light having a color temperature of 2850K to less than 5000K (Examples 9 and 11) and a color temperature of 5000K to 10,000K (Examples 10 and 12). The results are shown in Tables 4 and 5. Examples 11 and 12 are based on a phosphor sheet in which a resin containing phosphor 2 is formed into a sheet shape.

  As is apparent from Tables 4 and 5, the thickness (wall thickness) t of the phosphor-containing resin layer 9 or phosphor sheet and the content of the phosphor 2 are appropriately adjusted as shown in Tables 4 and 5. By balancing, white light having a color temperature of 2850 to 5000K could be obtained in Examples 9 and 11, and white light having a color temperature of 5000 to 10000K could be obtained in Examples 10 and 12. That is, it has been found that by using a blue light emitting LED chip and appropriately adjusting the phosphor content in the resin layer and its thickness, a wide range of white light from the light bulb color to daylight can be obtained.

It is sectional drawing which shows the structure of 1st Embodiment which applied the light-emitting device of this invention to the LED lamp. It is a top view which shows an example of the light emitting diode module which has arrange | positioned two or more LED lamps shown in FIG. It is the sectional view on the AA line of FIG. It is sectional drawing which shows the structure of 2nd Embodiment which applied the light-emitting device of this invention to the LED lamp. It is a figure which shows the relationship between the thickness of a fluorescent substance containing resin layer, and the luminous efficiency of an LED lamp. It is a top view of the light-emitting device concerning a 3rd embodiment. It is F2-F2 sectional view taken on the line of FIG. It is a graph which shows the relationship between the thickness of a fluorescent substance containing resin layer, and color temperature. It is a graph which shows the relationship between the thickness of a fluorescent substance containing resin layer, and an efficiency ratio.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,31 ... LED lamp, 2 ... LED chip, 3 ... Cavity, 5 ... Board | substrate, 6 ... Frame, 8 ... Circuit pattern, 9 ... Phosphor containing resin layer, 21 ... Light emitting diode module, 32 ... Transparent resin layer, 33 ... phosphor sheet.

Claims (5)

A light emitting element;
A transparent resin and a phosphor-containing resin layer having a thickness of 400 to 800 μm, which is disposed so as to cover the light emitting element, containing 5 to 20% by weight of the phosphor with respect to the transparent resin;
A light-emitting device comprising: A substrate having a recess;
A light emitting device disposed in the recess;
A transparent resin layer arranged to cover the light emitting element;
A sheet-like phosphor-containing resin layer having a thickness of 300 to 800 μm and containing a transparent resin and 5 to 20% by weight of the phosphor with respect to the transparent resin and arranged to cover the concave portion of the substrate;
A light-emitting device comprising:   The light emitting element has a light emitting diode chip that emits blue light, and the phosphor is excited by blue light emitted from the light emitting diode chip to emit light between yellow-green light and orange light. The light emitting device according to claim 1, further comprising a phosphor. A light emitting element emitting blue light;
It has a yellow phosphor having an average particle size of 10 to 20 μm and a transparent resin, and the blending ratio of the phosphor when the film thickness is 400 to 500 μm is 15.0 to 17.0% by weight with respect to the transparent resin. The blending ratio of the phosphor when the film thickness is 500 to 600 μm is 12.0 to 15.0 wt% with respect to the transparent resin, and the blending ratio of the phosphor when the film thickness is 600 to 700 μm is the above. 10.0 to 12.0% by weight with respect to the transparent resin, and the blending ratio of the phosphor when the film thickness is 700 to 800 μm is 7.5 to 10.0% by weight with respect to the transparent resin, A phosphor-containing resin layer configured such that the blue color from the light-emitting element and the yellow color from the phosphor are mixed to have a color temperature of 2850K (Kelvin) or more and less than 5000K;
A light-emitting device comprising: A light emitting element emitting blue light;
It has a yellow phosphor with an average particle size of 10 to 20 μm and a transparent resin, and the blending ratio of the phosphor when the film thickness is 400 to 500 μm is 12.0 to 15.0% by weight with respect to the transparent resin. The blending ratio of the phosphor when the film thickness is 500 to 600 μm is 10.0 to 12.0 wt% with respect to the transparent resin, and the blending ratio of the phosphor when the film thickness is 600 to 700 μm is the above-mentioned. It is 7.5 to 10.0% by weight with respect to the transparent resin, and the blending ratio of the phosphor when the film thickness is 700 to 800 μm is 6.5 to 7.5% by weight with respect to the transparent resin. A phosphor-containing resin layer configured such that the blue color from the light-emitting element and the yellow color from the phosphor are mixed to have a color temperature of 5000 K (Kelvin) to 10,000 K;
A light-emitting device comprising:

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