JP5194675B2 - Light emitting device - Google Patents

Description

  The present invention relates to a light emitting device such as a light emitting diode 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, and indoor / outdoor advertisements. In addition, LED lamps have features such as long life and high reliability, and low power consumption, impact resistance, high-speed response, high purity display color, lightness, thinness, etc. It is also in the spotlight for general lighting. When such an LED lamp is applied to various uses, it is important to obtain white light emission.

  Typical methods for realizing white light emission with an LED lamp are (1) a method using three LED chips that emit light in blue, green and red colors, and (2) a blue light emitting LED chip and yellow or orange light emission. And (3) a method of combining an ultraviolet light emitting LED chip and a blue, green and red light emitting three-color mixed phosphor (hereinafter referred to as RGB phosphor). . Of these, the method (2) is generally widely used.

  As the structure of the LED lamp to which the above-described method (2) is applied, a transparent resin mixed with a phosphor is poured into a cup-shaped frame equipped with an LED chip, and the resin layer containing the phosphor is solidified by pouring it. A structure in which is formed is proposed (see, for example, Patent Document 1). In addition, a chip-on-board (COB) in which a phosphor-containing resin layer is formed on a large number of LED chips mounted on a substrate (board) by applying a transparent resin mixed with a phosphor for the purpose of increasing brightness. A structure has also been developed. Furthermore, a technology has also been proposed in which a phosphor-containing resin sheet formed by molding a transparent resin mixed with a phosphor into a sheet is fixed to a frame on which LED chips are arranged to reduce color unevenness and color difference between cups. Yes.

  In recent years, in LED lamps for general illumination, the color appearance called color rendering properties has been emphasized. Color rendering is an evaluation of the color appearance by a light source using illumination close to natural light as reference light, and is represented by a color rendering index. The color rendering index is the numerical value of the color shift when the test color specified in JIS is illuminated with the sample light source and the reference light, and when viewed with the reference light, the color is evaluated as 100. The numerical value decreases as the deviation increases, and the closer to 100, the better the color rendering.

  The color rendering index includes an average color rendering index Ra and a special color rendering index Ri. 1-No. It is expressed as an average value of 8 color rendering evaluation values. In the special color rendering index Ri, the test No. The individual values of i's color rendering index are used.

  White LEDs, which are currently in the mainstream, are a combination of a blue light emitting LED chip and a yellow or orange light emitting phosphor. This type of LED has insufficient redness, so that color rendering is not sufficient. There wasn't. For this reason, in addition to yellow or orange light emitting phosphors, color rendering properties are improved by blending red light emitting phosphors such as nitrides and sulfides.

  That is, in a so-called high color rendering LED lamp with a high Ra, color rendering is performed by combining the yellow light emitted from the yellow phosphor emitted by the blue light from the LED chip with the red light (for example, the main wavelength 620 nm) from the red phosphor. Synthesizing white light with excellent properties.

  However, in such a high color rendering type LED lamp, the red phosphor absorbs not only blue light having a wavelength of 460 nm from the LED chip but also yellow light emitted from the yellow phosphor and is used for excitation. There has been a problem that the light extraction efficiency is greatly reduced.

Accordingly, as a countermeasure against this, an LED lamp using a mixture of a green phosphor and a red phosphor (or an orange phosphor) has been proposed (for example, see Patent Document 2). A method for selecting the dominant wavelength of the red phosphor has also been proposed (see, for example, Patent Document 3). The red region is usually 600 nm or more and generally 670 nm, but a region having a wide range up to 780 nm is selected.
JP 2001-148516 A JP 2004-327518 A JP 2005-322673 A

  However, in the LED lamp described in Patent Document 2, since green light from the green phosphor is often used as excitation light, it has not led to sufficient improvement in luminous efficiency and Ra.

Further, in the LED lamp described in Patent Document 3, it is necessary to strictly select the main wavelength when the decrease in light emission efficiency is reduced and Ra improvement is taken into consideration. In addition, nitride-based red phosphors such as Ca ₂ Sr ₅ N ₈ : Eu and CaAlSiN ₃ : Eu are less likely to grow crystals, and the efficiency of grain size is also reduced in other nitride-based red phosphors. Therefore, it was necessary to select the best wavelength from a wide wavelength range and to set the phosphor particle size strictly. When the particle size of the phosphor is small, not only the light emission efficiency does not increase, but also the blue light emission from the LED chip and the light emission path of the yellow light emission excited and emitted by this blue light are blocked, and the light extraction efficiency decreases. become.

  As an LED lamp for general illumination, there is a demand for a light emitting device that has Ra (80 to 85) value of a three-wavelength fluorescent lamp as an index, has little decrease in luminous efficiency, and realizes Ra 80 to 85.

  An object of the present invention is to provide a light emitting device that realizes an improvement in light emission efficiency and is capable of adjusting Ra with high color rendering properties.

The light-emitting device according to claim 1 is a light-emitting element having a light-emitting diode chip that emits blue light; a transparent resin; and a half wavelength with a dominant wavelength of 540 nm to less than 585 nm excited by blue light emitted from the light-emitting diode chip. One type of silicate phosphor (A) that emits visible light having a value range of 70 to 110 nm and a blue light emitted from the light emitting diode chip, the main wavelength is 585 nm to 630 nm, and the half value width is 70 to Each of the silicate phosphors (B) that emit light of 110 nm contains at least one phosphor having a smaller half-value width than a phosphor having a larger half-value width so as to cover the light-emitting element. arranged and phosphor-containing resin layer; comprises a, the average color rendering index Ra is 80 to 85, the special color rendering index R9 is 9-85 It is a symptom.

The light-emitting device according to claim 2 is the light-emitting device according to claim 1, wherein the phosphor is composed of one kind of the silicate phosphor (A) and a half-value width of the silicate phosphor (A). It has two or more of the silicate phosphors (B) smaller than the half-value width, respectively .

The light-emitting device according to claim 3 is the light-emitting device according to claim 1 or 2, wherein the phosphor-containing resin layer further has a main wavelength of more than 630 nm and a half-value width of the silicate phosphor (A). the larger nitride phosphor half width, the total of the nitride phosphor and the silicate-based phosphor (B), is characterized by having more than the silicate-based phosphor (a).

Furthermore, the light emitting device according to claim 4 is the light emitting device according to any one of claims 1 to 3 , wherein the light emitting element has a wire bonding connection structure, and the phosphor is mixed with the transparent resin. The ratio is 10 to 20% by weight in total of two or more kinds of phosphors, and the thickness (optical path length) of the phosphor-containing resin layer is 0.3 to 1.2 mm.

Furthermore, the light-emitting device according to claim 5 is the light-emitting device according to any one of claims 1 to 4 , wherein the light-emitting element has a flip chip connection structure, and the phosphor with respect to the transparent resin. The blending ratio is 10 to 20% by weight in total of two or more kinds of phosphors, and the thickness (optical path length) of the phosphor-containing resin layer is 0.15 to 1.2 mm. .

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, etc. 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 such a light emitting element (for example, blue light) to emit visible light, and a desired emission color is obtained by mixing the visible light and the light emitted from the light emitting element. Is.

  As the phosphor in the present invention, a mixture of two or more phosphors having an emission spectrum having a half-width of 70 to 110 nm at the dominant wavelength is used. The half-value width refers to the spread width (wavelength) of the spectrum at a height that is ½ of the peak. If a phosphor having an emission spectrum with a half-value width of less than 70 nm at the dominant wavelength is used, even if two or more kinds of phosphors are mixed, high color rendering light emission cannot be obtained. In addition, when a phosphor having an emission spectrum with a half width exceeding 110 nm is used, it is difficult to realize high emission efficiency.

  In the present invention, a phosphor that emits yellow or orange light having a dominant wavelength of 540 to 585 nm is referred to as a yellow phosphor, and emits orange or red-orange light having a dominant wavelength of more than 585 nm and not more than 630 nm. Although the phosphor to be described is an orange phosphor, particularly when the phosphor is specified by describing the dominant wavelength of light emission, a phosphor emitting green light or yellow-green light having a dominant wavelength of 520 to 540 nm, It may be included in the yellow phosphor.

  The phosphor-containing resin layer is a layer that holds the phosphor, and is formed by applying and solidifying a transparent resin in which two or more kinds of phosphors are mixed so as to cover the light emitting element. As the transparent resin, for example, a liquid transparent resin such as an epoxy resin or a silicone resin can be applied. In order to improve luminous efficiency, the blending ratio of the phosphor to the transparent resin is 10 to 20% by weight in total of the two or more phosphors, and the thickness of the phosphor-containing resin layer corresponding to the optical path length is When the electrode connection of the light emitting element is made by wire bonding, the thickness is preferably 0.3 to 1.2 mm. Moreover, when the light emitting element has a flip-chip electrode connection structure, the thickness (optical path length) of the phosphor-containing resin layer is preferably 0.15 to 1.2 mm.

  The average color rendering index Ra is obtained by quantifying the magnitude of the color shift when the test color is illuminated with the sample light source and the reference light. Ra has a sufficiently high color rendering property as a general illumination device having an Ra of 80 or more and corresponding to a three-wavelength fluorescent lamp.

  According to the light emitting device of claim 1, since it has two or more kinds of phosphors that emit visible light having a half width of 70 to 110 nm, light emission efficiency is hardly reduced and light emission with high color rendering properties is achieved. Can be obtained. In addition, the Ra value can be easily adjusted by changing the emission color (main wavelength) of the phosphor.

The light-emitting device according to claim 1 has two or more types of LED chips and yellow phosphors that emit yellow light or orange light having a half-value width of 70 to 110 nm by blue light from the LED chips. Therefore, high color rendering properties of Ra 80 to 85 can be realized while maintaining high luminous efficiency.

According to the light emitting device of claim 1 , an LED chip, a yellow phosphor that emits yellow light or orange light having a main wavelength of 540 to 585 nm and a half width of 70 to 110 nm by blue light from the LED chip, Since each of the phosphors emits orange or reddish orange light having a wavelength of more than 585 nm and less than 630 nm and a half-value width of 70 to 110 nm, high color rendering properties of Ra 80 to 85 while maintaining high luminous efficiency Can be realized.

According to the light emitting device of claim 4 , the phosphor (containing optical path length) is 0.3 to 1.2 mm after the phosphor blending ratio with respect to the transparent resin is 10 to 20 wt%. By adjusting to, the light emission efficiency of the light emitting device in which the light emitting element is connected by wire bonding can be further improved.

According to the light emitting device of claim 5 , the blending ratio of the phosphor to the transparent resin is 10 to 20% by weight, and the thickness (optical path length) of the phosphor-containing resin layer is 0.15 to 1.2 mm. By adjusting to, the light emission efficiency of the light emitting device in which the light emitting element is flip-chip connected can be further improved.

  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 a light emitting device of the present invention is applied to an LED lamp. 2 is a plan view showing an example of an LED module in which a plurality of LED lamps shown in FIG. 1 are arranged in a matrix of 3 rows and 3 columns on one plane, for example. FIG. It is AA sectional view.

  The LED lamp 1 shown in FIG. 1 has a blue light emitting type LED chip 2 as a light emitting element. The LED chip 2 is mounted on a substrate 4 having a circuit pattern 3. As the substrate 4, a flat plate made of aluminum (Al), nickel (Ni), glass epoxy resin or the like having heat dissipation and rigidity is used, and a cathode side and an anode side are disposed on the substrate 4 through an electric insulating layer 5. A circuit pattern 3 is formed. The circuit pattern 3 is made of an alloy of Cu and Ni, Au, or the like.

  The bottom electrode of the LED chip 2 is electrically connected to the circuit pattern 3 on one electrode side, and the top electrode is connected to the circuit pattern 3 on the other electrode side via a bonding wire 6 such as a gold wire. Electrically connected.

  On the substrate 4, a frame 8 made of resin or the like having a recess 7 is provided. The frame 8 is made of a synthetic resin such as PBT (polybutylene terephthalate), PPA (polyphthalamide), or PC (polycarbonate), and the LED chip 2 is disposed in the recess 7.

  And in the recessed part 7 in which the LED chip 2 was accommodated, the phosphor containing resin which mixed and disperse | distributed the 2 or more types of fluorescent substance which light-emits visible light whose half width of a main wavelength is 70-110 nm in transparent resin. The LED chip 2 is covered with such a phosphor-containing resin layer 9. As the transparent resin, for example, a silicone resin or an epoxy resin is used. The phosphor-containing resin layer 9 is formed by adding and mixing phosphors to a transparent resin, and then filling the phosphor-containing resin into the recesses 7 in which the LED chips 2 are disposed using a dispenser and heat curing. Is done.

  In order to improve luminous efficiency, the blending ratio of the phosphor to the transparent resin is preferably 10 to 20% by weight in total of two or more kinds of phosphors. More preferably, it is 13 to 15% by weight. Further, as in this embodiment, in the structure in which the LED chip 2 is connected to the circuit pattern 3 via the bonding wire 6 (wire bonding connection structure), the thickness of the phosphor-containing resin layer 9 corresponding to the optical path length is as follows. The thickness is 0.3 to 1.2 mm, and more preferably 0.5 to 0.9 mm. When the thickness of the phosphor-containing resin layer 9 is less than 0.3 mm, the amount of the phosphor used for light emission is reduced, resulting in a decrease in light emission efficiency. Moreover, it is difficult for the phosphor-containing resin layer 9 to sufficiently cover the upper end portion of the bonding wire 6, and the bonding wire 6 is easily exposed. On the other hand, when the thickness of the phosphor-containing resin layer 9 exceeds 1.2 mm, the light emitted from the LED chip 2 is difficult to reach the upper part of the phosphor-containing resin layer 9, and the phosphor in the phosphor-containing resin layer 9 It becomes difficult to sufficiently excite the entire amount of the light, and it becomes difficult to obtain a desired light amount. In order to secure a necessary and sufficient amount of phosphor and suppress a decrease in light emission efficiency, the depth of the concave portion 2 (distance from the opening end to the bottom surface of the concave portion 2) is usually about 1.0 mm. In many cases, the thickness of the phosphor-containing resin layer 9 is limited to the depth of the recess 2 or less.

  As the phosphor, two or more kinds of phosphors that are excited by blue light emitted from the LED chip 2 and emit visible light having a half-value width of a main wavelength of 70 to 110 nm are used. When a phosphor having a broad emission peak whose half-value width is out of the above range or an emission peak that is too sharp is used, light emission with high efficiency and high color rendering cannot be obtained. That is, when a phosphor having an emission spectrum with a half-width at less than 70 nm at the dominant wavelength is used, even if two or more kinds of phosphors are mixed, light with high color rendering cannot be obtained. In addition, when a phosphor having an emission spectrum with a half width exceeding 110 nm is used, it is difficult to realize high emission efficiency. Furthermore, even when only one type of phosphor that emits visible light having a half-value width of 70 to 110 nm is used, the color rendering properties are lowered, so that it is difficult to obtain light with high efficiency and high color rendering properties.

  In the LED lamp 1 of the first embodiment, a yellow phosphor that is excited by blue light from the LED chip 2 and emits light between yellow light and orange light having a half-value width of 70 to 110 nm of the main wavelength. By using two or more types, high color rendering properties with an average color rendering index Ra of 80 to 85 can be realized.

  Two types of yellow phosphors emitting light between yellow-green light and orange light having a dominant wavelength of 520 to 585 nm, a difference of dominant wavelengths of 25 to 65 nm, and a half-value width of 70 to 110 nm at the dominant wavelength By using, high color rendering properties can be achieved while maintaining high luminous efficiency.

  Further, a yellow phosphor that emits light between yellow light and orange light having a dominant wavelength of 540 to 585 nm and a half width of 70 to 110 nm; By using in combination with an orange phosphor that emits light between red light and orange light, high color rendering properties with an Ra of 80 to 85 can be realized. The compounding ratio of the yellow phosphor having a dominant wavelength of 540 to 585 nm and the orange phosphor having a dominant wavelength of more than 585 nm and not more than 630 nm can be changed within a range of 3.5: 1 to 2.0: 1. Ra and color temperature can be adjusted by adjusting the blending ratio.

  Furthermore, two or more kinds of the above-described yellow phosphor (main wavelength is 540 to 585 nm and half width is 70 to 110 nm) and the above-described orange phosphor (main wavelength is more than 585 nm and less than 630 nm and half width is 70). ˜110 nm) can also be used in combination.

  When an orange phosphor having a dominant wavelength of more than 585 nm and not more than 630 nm is used, a phosphor emitting reddish orange light having a dominant wavelength of 600 to 630 nm can be used in combination. Furthermore, a green phosphor that emits light between green light and yellow-green light having a dominant wavelength of 510 to 540 nm and a half width of 70 to 110 nm is combined with the yellow phosphor or orange phosphor or both of them. It is also possible to use it.

A yellow phosphor emitting a yellow or orange light having a dominant wavelength of 540 to 585 nm and a half-value width of 70 to 110 nm, and an orange or red-orange light having a dominant wavelength of more than 585 nm and not more than 630 nm and a half-value width of 70 to 110 nm Examples of the orange-based phosphor that emits AE ₂ SiO ₄ : Eu phosphor (AE represents an alkaline earth element such as Sr, Ba, and Ca), Mg ₂ SiO ₄ : Eu phosphor, Zn ₂ Silicate (silicate) -based phosphors such as SiO ₄ : Eu phosphors may be mentioned and selected from these phosphors. Further, a phosphor having the main wavelength and a half-value width is selected from sialon phosphors (for example, AE _x (Si, Al) ₁₂ (N, O) ₁₆ : Eu) and oxide phosphors. It can also be used. In addition, the above-described AE ₂ SiO ₄ : Eu phosphor and Mg ₂ SiO ₄ : Eu fluorescence are also used as yellow phosphors emitting yellow-green light or orange light having a dominant wavelength of 520 to 585 nm and a half width of 70 to 110 nm. Phosphors having the above-mentioned dominant wavelength and half-value width can be selected and used from among phosphors, silicate phosphors, sialon phosphors, and oxide phosphors.

Examples of red phosphors that emit red light having a dominant wavelength exceeding 630 nm and a half width of 70 to 110 nm include nitride phosphors such as CaAlSiN ₃ : Eu phosphor and Sr ₂ Si ₅ N ₈ : Eu phosphor. These phosphors can be selected and used.

  In the LED lamp 1 of the first embodiment, the applied electric energy is converted into blue light having a dominant wavelength of, for example, 460 nm by the LED chip 2 and emitted, and the emitted blue light is emitted from the phosphor-containing resin layer 9. Are two or more kinds of phosphors having an emission peak with a half-value width of 70 to 110 nm, and are converted into light having a longer wavelength. And the white light which is a color based on the blue light radiated | emitted from LED chip 2, and the luminescent color of these fluorescent substance is discharge | released from the LED lamp 1. FIG.

  And in the LED lamp 1 of 1st Embodiment, it has two or more types of fluorescent substance which light-emits visible light whose half value width is 70-110 nm excited by the blue light radiated | emitted from LED chip 2. FIG. Therefore, it is possible to obtain light emission with little reduction in efficiency and high color rendering properties. In addition, by using a combination of phosphors having different main wavelengths as two or more kinds of phosphors, the value of Ra can be easily adjusted, and high color rendering properties of Ra 80 to 85 can be realized.

  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. Further, in this embodiment, the flat type SMD type LED lamp 1 has been described as an example, but 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)
FIG. 4 is a cross-sectional view showing a configuration of an LED lamp which is a second embodiment of the light emitting device of the present invention. In FIG. 4, the same reference numerals are used for the same constituent elements as those in FIG. 1 showing the first embodiment, and the description thereof is omitted.

  In the second embodiment, connection with the electrode of the LED chip 2 is performed by flip chip connection. That is, the LED chip 2 is mounted on the substrate 4 so that the electrode formation surface faces downward (face down), and the electrode pads are electrically connected to the circuit pattern 3 via the solder bumps 10.

  And in the recessed part 7 in which the LED chip 2 was accommodated, a phosphor-containing resin in which two or more kinds of phosphors emitting visible light having a spectrum half-value width of 70 to 110 nm were mixed and dispersed in a transparent resin. The LED chip 2 is covered with such a phosphor-containing resin layer 9. As the phosphor, a yellow phosphor and an orange phosphor similar to those in the first embodiment can be used in appropriate combination.

  In order to improve luminous efficiency, the blending ratio of the phosphor to the transparent resin is preferably 10 to 20% by weight, more preferably 13 to 15% by weight in total of two or more kinds of phosphors. The thickness (optical path length) of the phosphor-containing resin layer 9 is 0.15 to 1.2 mm, and more preferably 0.5 to 0.9 mm. When the thickness of the phosphor-containing resin layer 9 is less than 0.15 mm, the amount of the phosphor used for light emission is reduced, resulting in a decrease in light emission efficiency. On the other hand, when the thickness of the phosphor-containing resin layer 9 exceeds 1.2 mm, the light emitted from the LED chip 2 is difficult to reach the upper part of the phosphor-containing resin layer 9, and the phosphor in the phosphor-containing resin layer 9 It becomes difficult to sufficiently excite the entire amount of the light, and it becomes difficult to obtain a desired light amount.

  Since the LED lamp 1 of the second embodiment also has two or more types of phosphors that are excited by the blue light emitted from the LED chip 2 and emit visible light having a half width of 70 to 110 nm, Light emission with little reduction in efficiency and high color rendering properties can be obtained. In addition, by using a combination of phosphors having different main wavelengths as two or more kinds of phosphors, the value of Ra can be easily adjusted, and high color rendering properties of Ra 80 to 85 can be realized. Furthermore, since the flip chip connection structure is applied as the electrode connection structure of the LED chip 2, the light extraction efficiency to the upper surface of the LED chip 2 is improved.

(Third embodiment)
5 and 6 show a light-emitting device for forming an LED package according to the third embodiment of the present invention. FIG. 5 is a plan view of the light emitting device, and FIG. 6 is a longitudinal sectional view of the light emitting device shown in FIG. 5 cut along the line FF. 5 and 6, the same reference numerals are used for the same components as those in the drawings relating to the first embodiment.

  A light-emitting device (LED lamp) 1 shown in FIGS. 5 and 6 is bonded to a package substrate such as a device substrate 4, a reflective layer 31, a circuit pattern 3, and a plurality of LED chips such as a semiconductor light-emitting element 2, for example. The layer 32, the reflector 34, the phosphor-containing resin layer 9, and the light diffusion member 33 are formed. The phosphor-containing resin layer 9 also functions as a sealing member.

  The device substrate 4 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 4 is made of a synthetic resin, it can be formed of, for example, an epoxy resin containing glass powder. When the device substrate 4 is made of metal, the heat radiation from the back surface of the device substrate 4 is improved, the temperature of each part of the device substrate 4 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 heat conductivity of 10 W / m * K or more, specifically, aluminum or its alloy can be illustrated.

  The reflective layer 31 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 4. The reflective layer 31 can be made of a white insulating material having a reflectance of 85% or more in the wavelength region of 400 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, for example, by impregnating a sheet base material with a thermosetting resin mixed with a white powder such as aluminum oxide. The reflective layer 31 is bonded to the entire surface of the device substrate 4 by its own adhesiveness.

  The circuit pattern 3 is bonded to a surface of the reflective layer 31 opposite to the surface to which the device substrate 4 is bonded as an energizing element for each semiconductor light emitting element 2. The circuit pattern 3 is formed in two rows dotted at predetermined intervals in the longitudinal direction of the device substrate 4 and the reflective layer 31 in order to connect the semiconductor light emitting elements 2 in series, for example. The end-side circuit pattern 3a located on one end side of the row of one circuit pattern 3 is integrally formed with a power feeding pattern portion 3c. Similarly, the end located on one end side of the row of the other circuit pattern 3 The side circuit pattern 3a is integrally formed with a power feeding pattern portion 3d.

  The power feeding pattern portions 3 c and 3 d are provided side by side at one end in the longitudinal direction of the reflective layer 31, and are separated from each other and insulated by the reflective layer 31. An electric wire (not shown) that reaches the power source is individually connected to each of the power supply pattern portions 3c and 3d by soldering or the like.

  The circuit pattern 3 is formed by the procedure described below. First, a reflective layer 31 made of a prepreg impregnated with the uncured thermosetting resin is attached on the device substrate 4, and then a copper foil of the same size is attached on the reflective layer 31. Next, the laminated body thus obtained is heated and pressurized to cure the thermosetting resin, whereby the device substrate 4 and the copper foil are pressed against the reflective layer 31 to complete the adhesion. Next, after providing a resist layer on the copper foil and etching the copper foil, the remaining resist layer is removed to form the circuit pattern 3. The thickness of the circuit pattern 3 made of copper foil is, for example, 35 μm.

  Each semiconductor light emitting element 2 is made of, for example, a double wire type 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. The element substrate 2b is made of, for example, a sapphire substrate. The element substrate 2b is thicker than the circuit pattern 3, 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 well layers are alternately stacked. An n-side electrode is provided on the n-type semiconductor layer, and a p-side electrode is 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. 6, each semiconductor light emitting element 2 is disposed between circuit patterns 3 adjacent to each other in the longitudinal direction of the device substrate 4, and is bonded to the same surface of the white reflective layer 31 by an adhesive layer 32. . 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 31 by the adhesive layer 32. By this adhesion, the circuit pattern 3 and the semiconductor light emitting element 2 are arranged in a straight line on the same surface of the reflective layer 31. Therefore, the side surface of the semiconductor light emitting element 2 positioned in this arrangement direction and the circuit pattern 3 are close to each other. It is provided so as to face each other.

  The thickness of the adhesive layer 32 can be, for example, 5 μm or less. For the adhesive layer 32, for example, a translucent adhesive having a thickness of 5 μm or less and a light transmittance of 70% or more, for example, a silicone resin-based adhesive can be suitably used.

  As shown in FIGS. 5 and 6, the electrode of each semiconductor light emitting element 2 and the circuit pattern 3 disposed in proximity to both sides of the semiconductor light emitting element 2 are connected by a bonding wire 6. Further, the end-side circuit patterns 3b positioned on the other end side of the two rows of circuit patterns 3 rows are also connected by the bonding wires 6. Therefore, in this embodiment, each semiconductor light emitting element 2 is connected in series.

  The surface light source of the light emitting device 1 is formed by the device substrate 4, the reflective layer 31, the circuit pattern 3, each semiconductor light emitting element 2, the adhesive layer 32, and the bonding wire 6.

  The reflector 34 is not individually provided for each one or several semiconductor light emitting elements 2 but is a single one surrounding all the semiconductor light emitting elements 2 on the reflective layer 31, for example, as shown in FIG. Thus, it is formed with a rectangular frame, and the semiconductor light emitting element 2 is disposed in a recess 7 formed with the frame. The reflector 34 is bonded to the reflective layer 31, and a plurality of semiconductor light emitting elements 2 and circuit patterns 3 are housed therein, and the pair of power feeding pattern portions 3 c and 3 d are positioned outside the reflector 34. ing.

  The reflector 34 can be formed of, for example, a synthetic resin, and its inner peripheral surface is a reflective surface. The reflecting surface of the reflector 34 can be formed by vapor deposition or plating of a metal material having a high reflectance such as Al or Ni, or can be formed by applying a white paint having a high visible light reflectance. Alternatively, white powder can be mixed into the molding material of the reflector 34 to make the reflector 34 itself white with high visible light reflectivity. 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 34 so as to gradually open in the irradiation direction of the light emitting device 1.

  As in the first embodiment, the phosphor-containing resin layer 9 is a fluorescence obtained by dispersing and mixing two or more phosphors that emit visible light having a half-value width of an emission peak wavelength of 70 to 110 nm on a transparent resin. The phosphor-containing resin, which is composed of the body-containing resin, is filled so that the semiconductor light-emitting elements 2 and the bonding wires 6 arranged on the surface of the reflective layer 31 and in a straight line are filled, and solidified in the reflector 34. It is formed by letting. The liquid transparent resin that flows between the surface of the reflective layer 31 and the bonding wire 6 reaches each semiconductor light emitting element 2 and the bonding wire 6 due to a capillary phenomenon or the like, and the film thickness thereof is almost uniform. It is considered that the body 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.

  And in the fluorescent substance containing resin layer 9, the mixture ratio of the fluorescent substance with respect to transparent resin is 10 to 20 weight% in total of 2 or more types of fluorescent substance. The thickness of the phosphor-containing resin layer 9 corresponding to the optical path length is 0.3 to 1.2 mm.

  In the third embodiment configured as described above, high color rendering properties of Ra 80 to 85 can be realized while maintaining high luminous efficiency, and Ra can be adjusted by selecting the main wavelength of the phosphor. it can. Further, since there is reflection from the reflective layer 31, the light emission efficiency is improved.

  Next, examples and comparative examples of the present invention will be described.

Examples 2 to 4, 6, Comparative Examples 1 to 4, Reference Examples 1-1 and 1-5
Three types of yellow phosphors (silicate phosphors Y1, Y3 and YAG phosphor Y2) having the main wavelength and half-value width of light emitted by the blue LED chip have the values shown in Table 1. Three types of orange phosphors ( Silicate phosphors O1, O2, O3) and one kind of red phosphor (nitride phosphor R) were prepared. The particle diameters of these phosphors were not classified, and those having an upper limit of 45 μm were used.

Next, in Examples 2 to 4, 6, and Reference Examples 1-1 and 1-5 , two or more of these phosphors were used in combination as shown in Table 2, and Comparative Examples 1 to 1 were used. In No. 4, an LED lamp 1 having the configuration shown in FIG.

  That is, each phosphor was mixed and dispersed in the silicone resin at a blending ratio shown in Table 2 (blending ratio with respect to the silicone resin; wt%). Then, the obtained phosphor-containing silicone resin is filled with a dispenser into a cup (concave portion 7) having a depth of 1.0 mm and an opening diameter of 3 mm where the LED chip 2 emitting blue light having a wavelength of 460 nm is disposed. After that, the silicone resin was cured to produce an LED lamp 1 having a phosphor-containing resin 9 having a thickness (optical path length) of 1.0 mm.

Next, the LED lamps 1 obtained in Examples 2 to 4, 6, Reference Examples 1-1 and 1-5 and Comparative Examples 1 to 4 were caused to emit light, respectively, and an instantaneous spectrophotometer MCPD-7000 (Otsuka Electronics Co., Ltd.) Emission spectrum was measured. Then, the color temperature and the color rendering index (average color rendering index Ra and special color rendering index R9, R15) were calculated from the emission spectrum. Moreover, the luminous efficiency was measured using the gonio method. These measurement results are shown in Table 2. The luminous efficiency is a relative value when the efficiency of the LED lamp of Comparative Example 3 is 100%.

As is apparent from Table 2, in the LED lamps 1 obtained in Examples 2 to 4 and 6, the yellow phosphor having a half width of 70 to 110 nm and emitting yellow light or orange light, and the half width of 70 to 110 nm. Since two or more kinds of phosphors each including an orange phosphor that emits orange light or red-orange light are used, color rendering can be improved while maintaining high luminous efficiency. In particular, in the LED lamps 1 of Examples 2 to 4 and Example 6, high color rendering properties of Ra 80 or more can be realized.

Reference Examples 1-5
A yellow phosphor (silicate phosphor) having an emission main wavelength of 565 nm and a half width of 95 nm was mixed and dispersed in a silicone resin at a ratio of 10% by weight. Then, the obtained phosphor-containing silicone resin is filled with a dispenser into a cup (concave portion 7) having a depth of 1.0 mm and an opening diameter of 3 mm where the LED chip 2 emitting blue light having a wavelength of 460 nm is disposed. Thereafter, the silicone resin was cured, and LED lamps 1 having the phosphor-containing resin thicknesses (optical path lengths) shown in Table 3 were produced.

  Next, the LED lamps 1 obtained in Reference Examples 1 to 5 were each made to emit light, and the luminous efficiency was measured using the gonio method. The measurement results are shown in Table 3 and FIG. The luminous efficiency is a relative value when the efficiency of the LED lamp of Reference Example 4 in which the thickness of the phosphor-containing resin (optical path length) is 0.7 mm is 100%.

  From the graph of Table 3 and FIG. 7, in the LED lamp 1 in which the electrode connection of the LED chip 2 is made by wire bonding, the thickness of the phosphor-containing resin layer 9 is higher in Reference Examples 2 to 5 than 0.3 mm. In Reference Example 1 in which the luminous efficiency is obtained and the thickness of the phosphor-containing resin layer 9 is less than 0.3 mm, the luminous efficiency is significantly reduced.

  This reference example is a measurement result of the LED lamp 1 using one kind of yellow phosphor having a half width in the range of 70 to 110 nm. Two or more kinds of phosphors having a half width of 70 to 110 nm are included. Similar results were obtained when used.

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 LED 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 of the LED lamp concerning 2nd Embodiment of the light-emitting device of this invention. It is a top view of the light-emitting device concerning 3rd Embodiment of the light-emitting device of this invention. It is the FF sectional view taken on the line of FIG. It is a graph showing the measurement result of the luminous efficiency of the LED lamp obtained in Reference Examples 1-5.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... LED lamp, 2 ... LED chip, 3 ... Circuit pattern, 4 ... Board | substrate, 6 ... Bonding wire, 7 ... Recessed part, 8 ... Frame, 9 ... Phosphor containing resin layer, 10 ... Solder bump, 21 ... LED module.

Claims (5)

A light emitting device having a light emitting diode chip emitting blue light;
A transparent resin, one type of silicate phosphor (A) that emits light having a main wavelength of 540 nm to less than 585 nm and a half-value width of 70 to 110 nm excited by blue light emitted from the light-emitting diode chip; One or more silicate phosphors (B) that emit light having a main wavelength of 585 nm to 630 nm and a half width of 70 to 110 nm when excited by blue light emitted from a light emitting diode chip, and having a small half width. A phosphor-containing resin layer, each of which contains a phosphor having a larger body than a phosphor having a large half width, and is disposed so as to cover the light emitting element;
The light emitting device is characterized in that the average color rendering index Ra is 80 to 85 and the special color rendering index R9 is 9 to 85 .   The phosphor includes at least one of the silicate phosphor (A) and two or more of the silicate phosphor (B) having a half width smaller than the half width of the silicate phosphor (A). The light-emitting device according to claim 1. The phosphor-containing resin layer further dominant wavelength beyond 630nm half-width the silicate-based phosphor half width greater than the nitride phosphor of (A), the silicate-based and the nitride phosphor 3. The light emitting device according to claim 1, wherein the total amount of the phosphors (B) is greater than that of the silicate phosphors (A).   The light emitting element has a wire bonding connection structure, and the blending ratio of the phosphor with respect to the transparent resin is 10 to 20% by weight in total of two or more phosphors, and the phosphor-containing resin layer The light-emitting device according to claim 1, wherein the thickness (optical path length) of the light-emitting device is 0.3 to 1.2 mm.   The light-emitting element has a flip-chip connection structure, and the blending ratio of the phosphor with respect to the transparent resin is 10 to 20% by weight in total of two or more phosphors, and the phosphor-containing resin layer The light-emitting device according to claim 1, wherein a thickness (optical path length) of the light-emitting device is 0.15 to 1.2 mm.

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