JP4430264B2 - Surface mount light emitting device - Google Patents

Description

BACKGROUND OF THE INVENTION
[0001]
  The present invention relates to a light emitting device used for various light sources such as a backlight light source, a display, and an illumination, and an optical sensor, and particularly relates to a light emitting device having excellent reliability.
[Prior art]
[0002]
  Today, high-luminance and high-power semiconductor light-emitting elements and small and highly sensitive light-emitting devices have been developed and used in various fields. Such a light emitting device is utilized for, for example, a light source of an optical printer head, a light source of a liquid crystal backlight, a light source of various meters, various reading sensors and the like by taking advantage of features such as small size, low power consumption and light weight.
[0003]
  As an example of such a light emitting device,FIG.And a light emitting device as shown in FIG. A plastic package 5 in which the lead electrode 2 is inserted and formed integrally is used. The package has a recess for accommodating the light emitting element. The LED chip 1 as a light emitting element is die-bonded on the lead electrode 2 exposed from the bottom surface of the recess, and each electrode of the LED chip and the lead electrode 2 provided in the package are electrically connected by a gold wire 4 or the like. The LED chip disposed in the recess is sealed with a translucent mold resin 9 or the like. As a result, LED chips, wires, and the like disposed inside the package are protected from the external environment such as moisture and external force, and a highly reliable light-emitting device can be obtained.
[0004]
  However, such light-emitting devices have begun to be used under more severe environmental conditions due to the expansion of application fields. In a light emitting device used for an aircraft or a vehicle, for example, the temperature may change to −20 or lower and + 80 ° C. or higher depending on the outside temperature. There is also vibration at the same time as external pressure, thermal shock, and the like. In such a case, the LED chip peels off from the die bond resin due to expansion or contraction of the mold resin or the like, and the intensity and directivity of the emitted light change. In severe cases, wire breakage may occur and no light may be emitted.
[0005]
  The light emitting element generates heat due to power consumption. The light emitting device having the above configuration can release heat generated from the light emitting element to the substrate side through the lead electrode. However, the heat dissipation effect is not fully satisfactory. If a high current is applied to improve the output of the light emitting device, the temperature of the light emitting device rises due to insufficient heat dissipation by the package, and the operating speed of the device and the surroundings Cause deterioration of the resin present in the substrate.
[0006]
  On the other hand, a can-type package is conventionally used as a highly reliable package. For example,FIG.And a lead electrode 2 hermetically insulated and sealed through an insulator 3 such as glass in a through-hole formed in the thickness direction of the metal base 10 as shown in FIG. A stem for a semiconductor device is used. A light emitting element is electrically connected to the upper surface of such a stem. The can 11 with a window which has a collar part in the bottom part is airtightly sealed with a seal.
[0007]
  The light emitting device having such a configuration has a very high reliability as compared with the case where a resin is used as a constituent material because the package is made of metal and the inside is hollow. Excellent heat resistance and heat dissipation. For this reason, it is possible to increase the amount of current flowing through the light emitting device and improve the output.
[0008]
  However, in recent years, it has been desired to reduce the size and thickness of light-emitting devices in order to support high-density mounting, and accordingly, surface-mounted light-emitting devices are required instead of lead-type light-emitting devices. Therefore, when a surface-mount light-emitting device in which the lead electrode portion is simply shortened with the above-described configuration is formed, the reliability tends to drop sharply after the mounting process.
[Problems to be solved by the invention]
[0009]
  Accordingly, an object of the present invention is to solve the above-described problems, and to provide a light-emitting device that can emit light with high reliability and high luminance and is excellent in mass productivity.
[Means for Solving the Invention]
[0010]
  Therefore, the present invention includes a light emitting element, a metal package having a recess in which the light emitting element is accommodated, and a lid that seals the metal package and has a light-transmitting window.Surface mount typeIn the light emitting device, the metal package has a flange portion in the outer side direction of the recess, the lid has a flat surface facing the upper surface of the flange portion, and the package recess.Has a convex part corresponding toHaving a central portion,The central window portion contains a color conversion member having a thickness equal to or less than the thickness of the convex portion.It is characterized by that. As a result, a light emitting device that emits light with high reliability and high brightness and excellent mass productivity can be obtained.
[0011]
  Moreover, the window part arrange | positioned at the center part of the said lid may contain the color conversion member, and you may provide a color conversion member inside the window part of a lid.
[0012]
  Moreover, you may provide the glass which contained the color conversion member in the outer upper surface of the said lid.
[0013]
  The light emitting element may be an LED or an LD.
[0014]
  A dielectric multilayer thin film may be provided on the upper surface side of the color conversion member provided in the window portion of the lid.
DETAILED DESCRIPTION OF THE INVENTION
[0015]
  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As a light emitting device of the present invention, FIG. 5 shows a light emitting device capable of emitting white light.
[0016]
  The package 5 is made of metal and has a concave shape. The bottom surface of the recess has two through-holes penetrating in the thickness direction, and positive and negative lead electrodes 2 are inserted into the through-holes with an insulator 3 interposed therebetween. The LED chip 1 which is a light emitting element is disposed on the bottom surface of the concave portion of the package configured as described above, and each electrode of the LED chip is electrically connected to each lead electrode 2 by a wire 4. In the present embodiment, the upper surface of the recess has a flange 12 in the external direction.
[0017]
  As described above, the metal package 5 to which the LED chips are electrically connected is hermetically sealed with the lid 6 having the translucent window portion 7 so as to close the concave portion of the package. Here, the translucent window portion 7 contains a fluorescent material 8 capable of absorbing at least a part of the light from the LED chip and emitting different wavelengths. Hereafter, each structure of embodiment of this invention is explained in full detail.
[0018]
  (Light-Emitting Element 1) In the present invention, the light-emitting element 1 is not particularly limited, but when a fluorescent substance is used, a semiconductor light-emitting element having a light-emitting layer capable of emitting a wavelength capable of exciting the fluorescent substance is preferable. Examples of such semiconductor light emitting devices include various semiconductors such as ZnSe and GaN, but nitride semiconductors (In_XAl_YGa_1-XYN, 0 <X, 0 <Y, X + Y = 1) are preferred. Examples of the semiconductor structure include a homostructure having a MIS junction, a PIN junction, and a pn junction, a heterostructure, and a double heterostructure. Various emission wavelengths can be selected depending on the material of the semiconductor layer and the degree of mixed crystal. In addition, a single quantum well structure or a multiple quantum well structure in which the semiconductor active layer is formed in a thin film in which a quantum effect is generated can be used.
[0019]
  When a nitride semiconductor is used, a material such as sapphire, spinel, SiC, Si, ZnO is preferably used for the semiconductor substrate. In order to form a nitride semiconductor with good crystallinity with high productivity, it is preferable to use a sapphire substrate. A nitride semiconductor can be formed on the sapphire substrate by MOCVD or the like. A buffer layer made of GaN, AlN, GaAIN or the like is formed on the sapphire substrate, and a nitride semiconductor having a pn junction is formed thereon.
[0020]
  As an example of a light emitting device having a pn junction using a nitride semiconductor, a first contact layer formed of n-type gallium nitride, a first cladding layer formed of n-type aluminum nitride / gallium, and a nitride layer on a buffer layer Examples include a double hetero structure in which an active layer formed of indium gallium, a second cladding layer formed of p-type aluminum nitride / gallium, and a second contact layer formed of p-type gallium nitride are sequentially stacked.
[0021]
  Nitride semiconductors exhibit n-type conductivity without being doped with impurities. When forming a desired n-type nitride semiconductor, for example, to improve luminous efficiency, it is preferable to appropriately introduce Si, Ge, Se, Te, C, etc. as an n-type dopant. On the other hand, when forming a p-type nitride semiconductor, the p-type dopants such as Zn, Mg, Be, Ca, Sr, and Ba are doped. Since nitride semiconductors are not easily converted to p-type by simply doping with a p-type dopant, it is preferable to reduce resistance by heating in a furnace or plasma irradiation after introducing the p-type dopant. After the electrodes are formed, a light emitting element made of a nitride semiconductor can be formed by cutting the semiconductor wafer into chips.
[0022]
  When white light is emitted in the light emitting diode of the present invention, the emission wavelength of the light emitting element is preferably 400 nm or more and 530 nm or less, taking into consideration the complementary color relationship with the emission wavelength from the fluorescent material, deterioration of the translucent resin, and the like. More preferably, it is 490 nm or less. In order to further improve the excitation and emission efficiency of the light emitting element and the fluorescent material, 450 nm or more and 475 nm or less are more preferable.
[0023]
  In addition, since the package main body of this invention is comprised only with the metal which is an inorganic substance, there is no possibility that it may deteriorate with an ultraviolet-ray. Therefore, the light-emitting device of the present invention can use a light-emitting element having a main light emission wavelength in an ultraviolet region shorter than 400 nm or a short wavelength region of visible light. In addition, by combining the light-emitting element and a fluorescent material that can absorb a part of the wavelength and emit other wavelengths, a color conversion light-emitting device with less color unevenness can be obtained. Since such a color conversion type light emitting device basically uses only light emitted from the fluorescent material, color adjustment can be performed relatively easily. In particular, when using a light-emitting element having a wavelength in the ultraviolet region, compared to the case of using a semiconductor light-emitting element that emits visible light, it absorbs variations such as the wavelength of the semiconductor light-emitting element and depends only on the emission color of the fluorescent material. Since chromaticity can be determined, mass productivity can be improved. Here, when the fluorescent substance is bound to a light emitting device, it is preferable to use a resin that is relatively resistant to ultraviolet rays, glass that is an inorganic substance, or the like.
[0024]
  (Metal Package 5) The metal package 5 used in the light emitting device of the present embodiment has a concave shape, and has two through holes penetrating in the thickness direction on the bottom surface of the concave portion. The positive and negative lead electrodes 2 are respectively inserted through the. As long as at least one of the lead electrodes is inserted into the metal package and the insulator, the other lead electrode may be fixed so as to be conductive with the metal package as shown in FIG. If comprised in this way, since an insulator is not interposed from a light emitting element to one recessed part upper surface among the said packages, heat dissipation is improved and it is preferable.
[0025]
  Moreover, it is preferable that the metal package and the lead electrode are made of the same material, so that when these are fixed via an insulating member, the insulating member can be satisfactorily sealed without breaking the insulating member. . Further, when the lead electrode and the metal package are fixed with a conductive member, the adhesion at the metallized interface is improved.
[0026]
  The area of the main surface of the lead electrode 2 exposed from the bottom of the package recess is preferably 0.02 mm 2 to 0.2 mm 2, more preferably 0.05 mm 2 to 0 in consideration of miniaturization of the light emitting device and the accuracy of wire bonding. .15 mm2. The mounting surface facing the main surface of the lead electrode has a larger area than the main surface. As a result, the lead electrode serves as a leg of the light-emitting device and can be stably surface-mounted. Further, since the contact area with the mounting substrate is widened, the heat dissipation is improved. The lead electrode having such a shape can be obtained by, for example, pressing a columnar lead electrode from the mounting surface side, and can be formed into an inverted T shape, a divergent type, an inverted taper type, or the like.
[0027]
  Moreover, it is preferable that the side surface of the recessed part of a metal package is a taper shape. Thus, by providing the side surface with an inclination, the light extraction efficiency of the light emitting element disposed on the bottom surface is improved. Further, when the molded package is released from the molding die, it is possible to produce the package with high yield without applying excessive stress to the molded package.
[0028]
  In particular, the metal package used in the light emitting device of the present invention is characterized in that the uppermost surface of the recess is a flange extending outward. The flange portion serves as a welded portion when the concave portion is hermetically sealed with a lid. That is, the metal package used in the light emitting device of the present invention has a welded portion with the lid integrally formed in a bowl shape from the upper surface of the package toward the outside. Thus, by integrally molding the package body and the welded portion with the same material, Joule heat generated by seam welding can be radiated well. Thereby, it is possible to hermetically seal without adversely affecting other components, which is preferable.
[0029]
  Moreover, the said collar part is located in the upper surface of a recessed part. There is a possibility that the flange portion may be sunk downward due to heat during welding. However, by positioning the flange portion on the uppermost portion of the package that is away from the mounting surface as in the present invention, it is possible to mount it satisfactorily without problems. Compared with this, if the flange part which is a welded part is on a line parallel to the bottom surface of the package, there is a possibility that the flange part may be slid to the mounting surface line by welding, and the cracked part becomes an obstacle and emits light. It becomes difficult to mount the apparatus stably. In addition, when there is a large temperature difference between the melting point of the package base material and the melting point of the plating layer, a material having a low melting point scatters around the seam when the flange part and the lid are seam welded, and the insulating part between the lead electrode and the package is scattered. Adhesion may cause poor insulation and adversely affect operating characteristics. On the other hand, the above-described problem can be avoided in the light emitting device of the present invention because the insulating portion and the flange portion are separated from each other.
[0030]
  Further, as the material of the package, strong Kovar or iron can be preferably used. Thereby, a thin package can be formed. Kovar is an Fe—Ni—Co alloy, and has a thermal expansion coefficient close to that of low-melting glass used for an insulating member. Thereby, a light emitting device hermetically sealed with high accuracy can be obtained. Moreover, it is preferable to provide a reflective layer on the surface of the package material. The material of the reflective layer is not particularly limited as long as it reflects light from a light emitting element arranged in a package, a fluorescent material used together, or the like. When the Ag plating is provided on the surface of the package as the reflective layer, the reflection / scattering rate of the light of the package is improved, and the Ag layer becomes a brazing material for welding, and the adhesion between the light emitting element, the wire, and the lid and the package body is improved. Improved and preferred. Furthermore, when the Ag layer is plated matte, these effects are improved.
[0031]
  The thickness of the package is preferably 0.3 mm to 1.0 mm, more preferably 0.5 mm to 0.7 mm. If it is thinner than 0.3 mm, cracks will occur at the weld interface during seam welding with the lid, or the strength of the entire package will be reduced. When the airtightness becomes incomplete in this way, moisture penetrates into the inside, and the wires and the light emitting elements are corroded to reduce the reliability. On the other hand, when the film thickness is 1.0 mm or more, it is difficult for a pulse current to be transmitted to the welding interface, which may result in incomplete sealing. In addition, the light emitting device is increased in size and cost is increased. By configuring the metal package used in the present invention as described above, a highly reliable light emitting device can be obtained at low cost.
[0032]
  (Lid 6) The lid 6 used in the present embodiment has a window portion 7 made of a translucent member at the center as a light emitting surface. The lid uses a carbon sealing jig in a lid body having an opening for extracting light at the center, and a tablet-like glass serving as a window is placed in the opening and passed through the furnace. As a result, the glass and the lid main body are hermetically sealed and formed.
[0033]
  The material of the lid is preferably similar in thermal expansion coefficient to the translucent member of the package body and window portion. Further, it is preferable that the surface of the lid material has a Ni plating layer because the lid material can be protected.
[0034]
  As shown in FIG. 3, the lid has a flat surface corresponding to the flange portion of the package and a convex portion corresponding to the concave portion of the package, thereby facilitating positioning of the package and the lid and improving mass productivity. .
[0035]
  On the other hand, as shown in FIG. 2, when using a lid that has a plane corresponding to the flange of the package and is configured so that the central part is a convex part symmetrically with the package concave part from the plane that is the edge part, When providing a color conversion member inside the window portion of the lid, for example, when applying a liquid resin containing a fluorescent material, the liquid resin containing the fluorescent material is applied to the flange joint surface which is a seam welded portion of the lid. Inflow can be prevented. Further, by setting the thickness of the color conversion member to be equal to or less than the thickness of the convex portion, the color conversion member can inevitably be prevented from coming into contact with other components, and a light emitting device with a high yield can be obtained. It is done. Furthermore, if the window is formed in a lens shape having a curve as shown in FIG. 8, light convergence is good, and a light emitting device with excellent directivity is obtained.
[0036]
  (Fluorescent substance 8) In the light emitting device of the present embodiment, the fluorescent substance 8 is contained in the lid window. Here, the fluorescent substance used in the present invention will be described in detail.
[0037]
  The fluorescent material used in the light emitting device of this embodiment is activated by cerium that can emit light of different wavelengths by exciting light emitted from a semiconductor light emitting element having a light emitting layer made of a nitride semiconductor. It is based on a yttrium / aluminum oxide fluorescent material. As a specific yttrium / aluminum oxide fluorescent material, YAlO₃: Ce, Y₃Al₅O₁₂Y: Ce (YAG: Ce) or Y₄Al₂O₉: Ce, and also a mixture thereof. The yttrium / aluminum oxide phosphor may contain at least one of Ba, Sr, Mg, Ca, and Zn. Moreover, by containing Si, the reaction of crystal growth can be suppressed and the particles of the fluorescent material can be aligned.
[0038]
  In this specification, the yttrium / aluminum oxide phosphor activated by Ce is to be interpreted in a broad sense, and a part or all of yttrium is selected from the group consisting of Lu, Sc, La, Gd and Sm. Or a part or all of aluminum is used in a broad sense including a phosphor having a fluorescent action in which any one or both of Ba, Tl, Ga, and In are substituted.
[0039]
  More specifically, the general formula (Y_zGd_1-z)₃Al₅O₁₂: Photoluminescence phosphor represented by Ce (where 0 <z <1) or the general formula (Re_1-aSm_a)₃Re '₅O₁₂: Ce (where 0 <a <1, 0 <b <1, Re is at least one selected from Y, Gd, La, Sc, and Re ′ is at least one selected from Al, Ga, In) The photoluminescence phosphor shown in FIG.
[0040]
  Since this fluorescent material has a garnet structure, it is resistant to heat, light and moisture, and the peak of the excitation spectrum can be made around 450 nm. In addition, the emission peak is in the vicinity of 580 nm and has a broad emission spectrum that extends to 700 nm.
[0041]
  Further, the photoluminescence phosphor can increase the excitation light emission efficiency in a long wavelength region of 460 nm or more by containing Gd (gadolinium) in the crystal. As the Gd content increases, the emission peak wavelength shifts to a longer wavelength, and the entire emission wavelength also shifts to the longer wavelength side. That is, when a strong reddish emission color is required, it can be achieved by increasing the amount of Gd substitution. On the other hand, as Gd increases, the emission luminance of photoluminescence by blue light tends to decrease. Furthermore, in addition to Ce, Tb, Cu, Ag, Au, Fe, Cr, Nd, Dy, Co, Ni, Ti, Eu, and the like can be contained as desired.
[0042]
  Moreover, in the composition of the yttrium / aluminum / garnet phosphor having a garnet structure, the emission wavelength is shifted to the short wavelength side by replacing a part of Al with Ga. Further, by substituting part of Y in the composition with Gd, the emission wavelength is shifted to the longer wavelength side. When substituting a part of Y with Gd, it is preferable that the substitution with Gd is less than 10%, and the Ce content (substitution) is 0.03 to 1.0. If the substitution with Gd is less than 20%, the green component is large and the red component is small. However, by increasing the Ce content, the red component can be supplemented and a desired color tone can be obtained without lowering the luminance. With such a composition, the temperature characteristics are good and the reliability of the light emitting diode can be improved. In addition, when a photoluminescent phosphor adjusted so as to have a large amount of red component is used, it becomes possible to emit an intermediate color such as pink, and a light emitting device having excellent color rendering properties can be formed.
[0043]
  Such photoluminescent phosphors use oxides or compounds that easily become oxides at high temperatures as raw materials for Y, Gd, Al, and Ce, and mix them well in a stoichiometric ratio. Get raw materials. Alternatively, a mixed raw material obtained by mixing a coprecipitation oxide obtained by firing a solution obtained by coprecipitation of a solution obtained by dissolving a rare earth element of Y, Gd, and Ce in an acid in a stoichiometric ratio with oxalic acid and aluminum oxide. Get. An appropriate amount of fluoride such as barium fluoride or ammonium fluoride is mixed as a flux and packed in a crucible, and baked in air at a temperature range of 1350 to 1450 ° C. for 2 to 5 hours to obtain a baked product. Can be obtained by ball milling in water, washing, separating, drying and finally passing through a sieve.
[0044]
  In the light emitting device of the present invention, such a photoluminescent phosphor may be a mixture of yttrium / aluminum / garnet phosphor activated by two or more kinds of cerium and other phosphors.
[0045]
  On the other hand, when the emission spectrum emitted from the light-emitting element is in the ultraviolet region or visible light with extremely low visibility (for example, 420 nm or less), it absorbs at least a part of the emission spectrum and emits light having two or more emission peaks. It is preferable to use a fluorescent material that emits a spectrum and whose emission spectrum is fluorescence that is at least partially complementary to each other. Since the fluorescent material has two or more emission spectrum peaks including a complementary color region, the color tone of the fluorescent material itself is extremely small and absorbs the variation of the light emitting element, thereby suppressing the color tone shift of the light emitting device. it can. In the emission spectrum having two or more peaks, it is preferable that the half-value width of the emission peak on the short wavelength side is narrower than the half-value width of the emission peak on the longer wavelength side. Therefore, the light emitting device can be easily taken out and has excellent color rendering properties. Further, when another fluorescent material having an emission peak between the two or more emission peaks is used together with the fluorescent material, a light emitting device capable of emitting white light and emitting a desired intermediate color with high luminance can be obtained. . Furthermore, if the intensity ratio of two or more emission spectra, at least part of which are complementary colors, is adjusted depending on the composition, the white area can be sensitive to the human eye even with a slight shift, but this allows fine adjustment. Is possible.
[0046]
  As specific fluorescent materials, for example, an element represented by M including at least one selected from Mg, Ca, Ba, Sr, and Zn, and at least one selected from Mn, Fe, Cr, and Sn are used. An alkaline earth metal halogen apatite phosphor activated with Eu having an element represented by M ′ can be used, and a light emitting device capable of emitting white light with high luminance with high luminance can be obtained. In particular, an alkaline earth metal halogen apatite phosphor activated with Eu containing at least Mn and / or Cl is excellent in light resistance and environmental resistance. In addition, the emission spectrum emitted from the nitride semiconductor can be efficiently absorbed. Further, the white region can emit light, and the region can be adjusted by the composition. Further, it can emit yellow and red light with high brightness by absorbing the ultraviolet region of a long wavelength. Therefore, a light emitting device with excellent color rendering can be obtained. Needless to say, alkaline earth metal chloroapatite phosphors are included as examples of alkaline earth metal halogen apatite phosphors.
[0047]
  In the alkaline earth metal halogen apatite phosphor, the general formula is (M_1-xyEu_xM '_y) 10 (PO₄)₆C_l2(Wherein M includes at least one selected from Mg, Ca, Ba, Sr, and Zn, and M ′ includes at least one selected from Mn, Fe, Cr, and Sn). 0.0001 <x <0.5 and 0.0001 <y <0.5.), A light emitting device capable of emitting mixed color light with high productivity is obtained.
[0048]
  In addition to the alkaline earth metal halogen apatite phosphor, BaMg₂Al₁₆O₂₇: Eu, (Sr, Ca, Ba)₅(PO₄)₃Cl: Eu, SrAl₂O₄: Eu, ZnS: Cu, Zn₂GeO₄: Mn, BaMg₂Al₁₆O₂₇: Eu, Mn, Zn₂GeO₄: Mn, Y₂O₂S: Eu, La₂O₂S: Eu, Gd₂O₂When at least one phosphor selected from S: Eu is contained, more detailed color tone can be adjusted, and white light with high color rendering can be obtained with a relatively simple configuration.
[0049]
  The phosphor can be obtained by the following method. A predetermined amount of ammonium chloride and various compounds that can be converted into phosphate oxide or pyrolysis of the constituent elements and ammonium chloride are weighed and mixed with a ball mill or the like, and then placed in a crucible.₂, H₂In a reducing atmosphere, baking is performed at a temperature of 800 ° C. to 1200 ° C. for 3 to 7 hours. The obtained fired product is wet pulverized, sieved, dehydrated and dried to obtain an alkaline earth metal halogen apatite phosphor.
[0050]
  As an alkaline earth metal halogen apatite phosphor (M_1-xyEu_xM '_y)₁₀(PO₄)₆Cl₂(Where M is at least one selected from Mg, Ca, Ba, Sr, and Zn, and M ′ is at least one selected from Mn, Fe, Cr, and Sn.) .0001 <x <0.5, 0.0001 <y <0.5.) X represents the composition ratio of the first activator Eu element, and 0.0001 <x <0.5 is preferable. When x is less than 0.0001, the light emission luminance decreases, and even when x exceeds 0.5, the light emission luminance tends to decrease due to concentration quenching. More preferably, 0.005 <x <0.4, and still more preferably 0.01 <x <0.2.
[0051]
  Y represents the composition ratio of at least one element of Mn, Fe, Cr, and Sn, preferably 0.0001 <y <0.5, and more preferably 0.005 <y <0. 4, more preferably 0.01 <y <0.3. If y exceeds 0.5, the emission luminance tends to decrease due to concentration quenching.
[0052]
  This phosphor can be obtained by exciting visible light having a relatively short wavelength from ultraviolet rays (for example, the main wavelength is 440 nm or less) from blue to white (for example, white in a conventional color of JIS Z8110, or The light emission color from white (the basic color) to red is shown.
[0053]
  In particular, since it can emit light efficiently and with high brightness even with ultraviolet rays having a relatively long wavelength of about 365 nm and sufficiently contains a red component, a good color rendering property with an average color rendering index Ra of 80 or more can be obtained. .
[0054]
  Moreover, it turns out that the said fluorescent substance can be variously changed into blue type-white type-red type by changing the composition ratio, and can adjust a color tone. That is, when M is Sr, the emission color is blue due to the emission of Eu2 + having a peak near 450 nm, but when the value of y is increased with Mn of M, the emission color of the phosphor is blue to white due to the emission of Mn. The light emission color of the system to red is shown. When M is Ca, the same amount of Eu and Mn is shown, but when M is Ba, the emission color changes little. Further, this phosphor used in the present invention is efficiently excited by long-wavelength ultraviolet light to relatively short-wavelength visible light (for example, 230 to 300 nm to 400 nm to 425 nm), and the emission color is the basic color name as defined in JIS Z8110. Included in the white area. Since this phosphor is efficiently excited in the entire ultraviolet region, it can be expected that it can be effectively used even for short wavelength ultraviolet rays.
[0055]
  A light emitting device using such a phosphor emits an emission spectrum having two peaks, a peak around 460 nm and a peak around 580 nm, among the above-described phosphors excited by ultraviolet LEDs or ultraviolet LDs. It becomes possible to do. The emission spectrum has at least a spectral component near 460 nm and a spectral component near 580 nm and emits fluorescence that is complementary to each other. As the phosphor emitting green light, the alkaline earth metal halogen apatite phosphor activated with Eu containing at least Mn and / or Cl is used.₂O₄: By adding Eu, color rendering can be further improved.
[0056]
  Furthermore, the above-mentioned phosphor can contain one kind selected from Tb, Cu, Ag, Au, Cr, Nd, Dy, Co, Ni, and Ti in addition to Eu as desired.
[0057]
  The particle size of the fluorescent material used in the present invention is preferably in the range of 1 μm to 100 μm, more preferably in the range of 10 μm to 50 μm, and even more preferably in the range of 15 μm to 30 μm. A fluorescent material having a particle size of less than 15 μm is relatively easy to form an aggregate, and is densely settled in a liquid resin, thus reducing the light transmission efficiency. In the present invention, by using such a fluorescent material that does not have a fluorescent material, concealment of light by the fluorescent material is suppressed and the output of the light emitting device is improved. In addition, the fluorescent material having a particle size range of the present invention has high light absorption and conversion efficiency and a wide excitation wavelength range. Thus, by including a large particle size fluorescent material having optically excellent characteristics, light around the dominant wavelength of the light emitting element can be converted and emitted well, and the mass productivity of the light emitting device is improved. Is done.
[0058]
  Here, in the present invention, the particle size is a value obtained from a volume-based particle size distribution curve. The volume-based particle size distribution curve is obtained by measuring the particle size distribution by a laser diffraction / scattering method. Specifically, in an environment of an air temperature of 25 ° C. and a humidity of 70%, hexametalin having a concentration of 0.05%. Each substance was dispersed in an aqueous sodium acid solution and measured with a laser diffraction particle size distribution analyzer (SALD-2000A) in a particle size range of 0.03 μm to 700 μm. In the present specification, the particle size value when the integrated value is 50% in this volume-based particle size distribution curve is referred to as the center particle size, and the center particle size of the fluorescent material used in the present invention is in the range of 15 μm to 50 μm. Is preferred. Moreover, it is preferable that the fluorescent substance which has this center particle size value is contained frequently, and the frequency value is preferably 20% to 50%. In this way, by using a fluorescent material with small variation in particle size, a light emitting device having a favorable color tone with suppressed color unevenness can be obtained.
[0059]
  The location of the fluorescent material is not particularly limited, and may be fixed to the light emitting element side of the lid window portion with a binder, or may be included in the material of the lid window portion. Moreover, it can also be contained in the die-bonding material which die-bonds a light emitting element. Further, as shown in FIG. 12, a glass containing a fluorescent substance may be fixed to the outer upper surface of the lid. Further, it may be contained in a resin that is relatively less deteriorated by heat and filled in the package recess so as to cover the light emitting element. Since the package of the present invention is made of metal and has excellent heat dissipation, even when the resin is filled in the recess, the resin is almost deteriorated by heat, and the original function of the resin and the fluorescent material is maximized. Can do.
[0060]
  In order to contain the fluorescent substance directly in the window portion of the lid, for example, when a mixture of glass powder or pellets and powder fluorescent substance is placed in the opening of the lid main body, The window is formed in such a manner that a fluorescent material is contained in the glass.
[0061]
  Moreover, when apply | coating a fluorescent substance to the window part of a lid using a binder, the material of a binder is not specifically limited, Both organic substance and inorganic substance can be used.
[0062]
  When using an organic substance as a binder, using a lid that has a flat surface corresponding to the flange portion of the package and is configured so that the central portion becomes a convex portion symmetrically with the package concave portion from the flat surface that is an edge portion, The color conversion member can be satisfactorily disposed in the convex portion without the resin leaking into the flange portion serving as the welding surface. As a specific material of the resin, a transparent resin excellent in weather resistance such as an epoxy resin, an acrylic resin, or silicone is preferably used. In particular, silicone is preferable because it is excellent in reliability and can improve the dispersibility of the fluorescent material.
[0063]
  In addition, it is preferable to use an inorganic substance as a binder because it is close to the thermal expansion coefficient of the window portion, and can be brought into close contact. As a specific method, a sol-gel method can be used. For example, fluorescent material, silanol (Si (OEt)₃OH) and ethanol are mixed to form a slurry. After the slurry is discharged from the nozzle to the window portion of the lid, the slurry is heated at 300 ° C. for 3 hours to convert silanol into SiO 2.₂The fluorescent material can be fixed to the lid window.
[0064]
  In addition, a binder such as an alkaline earth borate which is fine particles obtained by a precipitation method can also be used as a binder. The binder is so-called low melting glass. A color conversion member is constituted by adding a fluorescent substance to a slurry composed of 85 wt% of nitrocellulose or butyl acetate and 15 wt% of the borate, applying it to the window, and curing it by heating. In particular, when attaching a fluorescent substance having a large particle size, a binder in which the well particle is an ultrafine powder even if the melting point is high, such as silica, alumina made by Degussa, or a fine particle size alkali made by a precipitation method. It is preferable to use earth metal pyrophosphates, orthophosphates, etc., and these binders can be used alone or mixed with each other. Such a binder is preferably a fine particle, has little absorption with respect to radiation in the ultraviolet to visible region, and is extremely stable in the binder.
[0065]
  Here, a method of applying the binder will be described. In order to sufficiently enhance the binding effect, the binder is preferably used in the form of a slurry by wet pulverization in a vehicle and used as a binder slurry. A vehicle is a high viscosity solution obtained by dissolving a small amount of a binder in an organic solvent or deionized water. For example, an organic vehicle can be obtained by adding 1 wt% of nitrocellulose as a binder to butyl acetate as an organic solvent.
[0066]
  A fluorescent substance is contained in the binder slurry thus obtained to prepare a coating solution. The added amount of the slurry in the coating solution can be such that the total amount of the binder in the slurry is about 1 to 3% by weight with respect to the amount of the fluorescent substance in the coating solution. In order to suppress a decrease in the luminous flux maintenance factor, it is preferable that the amount of the binder added is small. Such a coating solution is applied to the back surface of the window portion. After that, hot air or hot air is blown to dry. Finally, baking is performed at a temperature of 400 ° C. to 700 ° C., and the vehicle is scattered to adhere the phosphor layer to a desired place with a binder.
[0067]
  (Diffusion Agent) Further, in the present invention, the color conversion member may contain a diffusion agent in addition to the fluorescent substance. As a specific diffusing agent, barium titanate, titanium oxide, aluminum oxide, silicon oxide or the like is preferably used. As a result, a light emitting device having good directivity can be obtained.
[0068]
  Here, in this specification, the diffusing agent refers to those having a center particle diameter of 1 nm or more and less than 5 μm. A diffusing agent having a size of 1 μm or more and less than 5 μm is preferable because it diffuses light from the light-emitting element and the fluorescent material well and can suppress color unevenness that tends to occur when a fluorescent material having a large particle size is used. In addition, the half width of the emission spectrum can be narrowed, and a light emitting device with high color purity can be obtained. On the other hand, a diffusing agent of 1 nm or more and less than 1 μm has a low interference effect with respect to the light wavelength from the light emitting element, but can increase the resin viscosity without lowering the luminous intensity. As a result, when the color conversion member is arranged by potting or the like, it becomes possible to disperse the fluorescent substance in the resin almost uniformly in the syringe and maintain the state, and the fluorescent substance having a large particle size that is relatively difficult to handle. Even when a substance is used, it is possible to produce with good yield. Thus, the action of the diffusing agent in the present invention varies depending on the particle size range, and can be selected or combined according to the method of use.
[0069]
  (Filler) Furthermore, in the present invention, the color conversion member may contain a filler in addition to the fluorescent substance. The specific material is the same as that of the diffusing agent, but the diffusing agent has a central particle size different from that of the diffusing agent. When the filler having such a particle size is contained in the translucent resin, the chromaticity variation of the light emitting device is improved by the light scattering action, and the thermal shock resistance of the translucent resin can be enhanced. Thereby, even when used at high temperatures, it is possible to prevent disconnection of the wire electrically connecting the light emitting element and the external electrode, peeling between the bottom face of the light emitting element and the bottom face of the recess of the package, etc. A high light emitting device can be obtained. Furthermore, the fluidity of the resin can be adjusted to be constant for a long time, and a sealing member can be formed in a desired place, and mass production can be performed with a high yield.
[0070]
  The filler preferably has a particle size and / or shape similar to that of the fluorescent material. Here, in this specification, the similar particle diameter means a case where the difference in the central particle diameter of each particle is less than 20%, and the similar shape means an approximate degree of each particle diameter with a perfect circle. This represents a case where the difference in the value of the degree of circularity (circularity = perimeter length of a perfect circle equal to the projected area of the particle / perimeter length of the projected particle) is less than 20%. By using such a filler, the fluorescent material and the filler interact with each other, and the fluorescent material can be favorably dispersed in the resin, thereby suppressing color unevenness. Furthermore, it is preferable that both the fluorescent substance and the filler have a center particle diameter of 15 μm to 50 μm, and more preferably 20 μm to 50 μm. By adjusting the particle size in this way, it is possible to arrange the particles with a preferable interval. As a result, a light extraction path is ensured, and the directivity can be improved while suppressing a decrease in luminous intensity due to filler mixing.
【Example】
[0071]
  Reference Example 1 A surface mount type light emitting device as shown in FIG. 1 is formed. The LED chip has a 475 nm In as a light emitting layer with a monochromatic emission peak of visible light._0.2Ga_0.8A nitride semiconductor element having an N semiconductor is used. More specifically, in the LED chip, TMG (trimethylgallium) gas, TMI (trimethylindium) gas, nitrogen gas and dopant gas are flowed together with a carrier gas on a cleaned sapphire substrate, and a nitride semiconductor is formed by MOCVD. Can be formed. SiH as dopant gas₄And Cp₂A layer to be an n-type nitride semiconductor or a p-type nitride semiconductor is formed by switching Mg.
[0072]
  As an element structure of the LED chip, an n-type GaN layer which is an undoped nitride semiconductor on a sapphire substrate, a GaN layer where an Si-doped n-type electrode is formed to become an n-type contact layer, and an n-type nitride semiconductor which is an undoped nitride semiconductor 5 layers of InGaN layers sandwiched between GaN layers, each comprising a type GaN layer, a GaN layer that constitutes a light emitting layer, a InGaN layer that constitutes a well layer, and a GaN layer that constitutes a barrier layer It is a multiple quantum well structure. On the light emitting layer, an AlGaN layer as a p-type cladding layer doped with Mg and a GaN layer as a p-type contact layer doped with Mg are sequentially laminated. (Note that a GaN layer is formed on the sapphire substrate at a low temperature to serve as a buffer layer. The p-type semiconductor is annealed at 400 ° C. or higher after film formation.) Nitride on the sapphire substrate by etching The surface of each pn contact layer is exposed on the same side of the semiconductor. Positive and negative pedestal electrodes were formed on each contact layer by sputtering. A metal thin film is formed on the entire surface of the p-type nitride semiconductor as a translucent electrode, and then a pedestal electrode is formed on a part of the translucent electrode. After drawing the scribe line on the completed semiconductor wafer, it is divided by an external force to form LED chips that are semiconductor light emitting elements.
[0073]
  On the other hand, recessTheAnd using a Kovar package having a flange on the outer side from the uppermost surface of the recess, so that the tip of the Kovar lead electrode is exposed from the inside of the recess in the through hole formed in the bottom of the package recess. Seal in an airtight manner. Next, an Ag plating film is formed on the package surface and the surface of the lead electrode.
[0074]
  The LED chip is die-bonded with a conductive epoxy resin on the bottom surface of the recess of the package body thus configured. Here, the bonding member used for die bonding is not particularly limited, and a resin or glass containing an Au—Sn alloy or a conductive material can be used. The conductive material contained is preferably Ag. When an Ag paste having a content of 80% to 90% is used, a light emitting device having excellent heat dissipation and low stress after bonding can be obtained. Moreover, it is preferable to use an Au—Sn alloy as a joining member in order to improve the reliability by using all the constituent members as metals. Next, each electrode of the die-bonded LED chip and each lead electrode exposed from the bottom surface of the package recess are electrically connected by an Au wire. Here, since resin is not used for the constituent members in this embodiment, Al wires can also be used.
[0075]
  Next, after sufficiently removing moisture in the recesses of the package, the recesses are sealed with a Kovar lid having a glass window at the center, and seam welding is performed.
[0076]
  When a reliability test is performed on the light emission measure obtained in this way, when the light emission output is measured after 500 hours have passed under If = 500 mA, there is almost no difference from the relative output, and a large amount of current can be applied. Even so, a light emitting device capable of maintaining a high output for a long time can be obtained. Reference Example 2 As in the reference example of FIG. 9, when a light emitting device is formed in the same manner as in Reference Example 1 except that the inside of the package recess is sealed with silicone without using a lid, light emission capable of maintaining high output for a long time. A device is obtained. This is considered to be the result of silicone that was originally deteriorated being able to dissipate the heat generated by the light emitting element satisfactorily by using the package of the present invention, and that the light scattering effect of silicone was fully exhibited. It is.
[0077]
  (Reference Example 3) As shown in FIG. 2, a lid having a flat surface corresponding to the flange portion of the package and having a central portion which is a convex portion symmetrical to the package concave portion from the flat surface which is an edge portion is used. Except for the above, when a light emitting device is formed in the same manner as in Reference Example 1, a light emitting device with good mass productivity can be obtained.
[0078]
  (Reference Example 4) As shown in FIG. 4, the side surface of the package recess has a tapered shape, the plane facing the upper surface of the flange portion of the package, and the direction of the recess of the packageSymmetricallyWhen a light emitting device is formed in the same manner as in Reference Example 1 except that a lid having a convex center part is used, the output is improved by 15% compared to Reference Example 1.
[0079]
  (Reference Example 5) As shown in FIG. 5, in the light emitting device of Reference Example 1, the plane facing the upper surface of the flange portion of the package and the direction of the concave portion of the packageAnd symmetricalBy using a lid having a convex central part and containing a fluorescent substance in the window part of the lid, a light emitting device with good mass productivity can be obtained.
[0080]
  Here, as the fluorescent material, a solution obtained by dissolving rare earth elements of Y, Gd, and Ce in acid at a stoichiometric ratio is coprecipitated with oxalic acid. A co-precipitated oxide obtained by firing this and aluminum oxide are mixed to obtain a mixed raw material. This is mixed with barium fluoride as a flux, packed in a crucible, and fired in air at a temperature of 1400 ° C. for 3 hours to obtain a fired product. The fired product is ball-milled in water, washed, separated, dried, and finally passed through a sieve to have a center particle size of 22 μm (Y_0.995Gd_0.005)_2.750Al₅O₁₂: Ce_0.250Form a fluorescent material.
[0081]
  A color conversion member is prepared by containing 50 wt% of the above-mentioned fluorescent substance in a slurry composed of 90 wt% of nitrocellulose and 10 wt% of γ-alumina, coating the light emitting element side window of the lid, and heating and curing at 220 ° C. for 30 minutes. Configure.
[0082]
  The color conversion type light-emitting device obtained in this way can obtain the same effects as those of Reference Example 1, and can emit white light with high reliability and high output.
[0083]
  Example 1 A light emitting device was formed in the same manner as in Reference Example 3 except that the light emitting element side window of the lid was filled with silicone containing 50 wt% of the fluorescent material instead of containing the fluorescent material in the window. When I didWhite light can be emitted with high reliability and high output.
[0084]
  (Embodiment 2) An embodiment except that, instead of containing a fluorescent material in the window portion, a silica gel containing 50 wt% of the fluorescent material is applied to the light emitting element side window portion of the lid to form a color conversion member. When the light emitting device was formed in the same manner as in No. 3,Example 1The same effect can be obtained.
[0085]
  (Reference Example 6) The LED chip uses a nitride semiconductor element having a 375-nm GaN semiconductor having an emission peak in the ultraviolet region as the light-emitting layer, and the Au-Sn alloy is formed in the recess of the same metal package as in Example 3. Then, the LED chip is die-bonded. Next, each electrode of the die-bonded LED chip and each lead electrode exposed from the bottom surface of the package recess are electrically connected by an Au wire.
[0086]
  Next, the fluorescent material is SrHPO as a raw material.₄, SrCO₃, Eu₂O₃, MnCO₃, NH₄Cl (Sr_0.96, Eu_0.01, Mn_0.03)₁₀(PO₄)₆Cl₂The composition ratio is adjusted and mixed. (SrHPO₄: 1000g, SrCO₃: 482.4 g, Eu₂O₃: 16.0 g, MnCO₃: 35.2 g, NH₄Cl: 116.5 g) The raw materials are weighed and mixed thoroughly by a dry method using a mixer such as a ball mill. This mixed raw material is packed in a crucible such as SiC, quartz, or alumina, and N₂, H₂In a reducing atmosphere, the temperature is raised to 1200 ° C. at 960 ° C./hr, and firing is performed at a constant temperature portion of 1200 ° C. for 3 hours. The obtained fired product is pulverized, dispersed, sieved, separated, washed with water and dried in water to obtain the desired phosphor powder.
[0087]
  Next, using the same lid as in Reference Example 3, a back surface TiO that is the surface facing the light emitting element of the light-transmitting window portion of the lid is used.₂/ SiO₂A dielectric multilayer thin film is formed. In the present embodiment, the arrangement position of the dielectric multilayer thin film is not limited to the above, and can be provided on the main surface and / or the back surface of the light-transmitting window portion of the lid.
[0088]
  Here, the dielectric multilayer thin film substantially reflects light in the ultraviolet region and substantially transmits visible light. In this embodiment, an LED chip that emits light in the ultraviolet region is used, but the dielectric multilayer thin film is formed on the rear surface of the transparent window portion of the lid, and a fluorescent material is applied to the rear surface of the dielectric multilayer thin film. As a result, the ultraviolet light absorbed by the fluorescent material is converted into wavelength and becomes visible light, which is extracted outside. On the other hand, the ultraviolet light that has not been absorbed by the fluorescent material and has not been wavelength-converted is almost completely reflected by the dielectric multilayer thin film, and is reflected by the dielectric multilayer thin film until the wavelength is converted to visible light by the fluorescent material. Thereby, the excitation light which is ultraviolet rays can be efficiently absorbed by the fluorescent material, and a light emitting device capable of emitting light with high luminance can be obtained. The dielectric multilayer thin film has a low absorption by selecting several to tens of layers of dielectric thin films of a high refractive index layer and a low refractive index layer alternately, and an arbitrary spectral reflectance is selected. And a reflectance close to 100% can be obtained for a specific wavelength. Specifically, TiO₂, Ta₂O₅And a high refractive index layer made of at least one substance selected from the group consisting of ZnS, and SiO.₂And MgF₂Preferably, the low refractive index layers made of at least one substance selected from the group consisting of are formed in layers.
[0089]
  Next, the obtained phosphor and SiO₂The filler or the diffusing agent is contained in a slurry composed of 90 wt% nitrocellulose and 10 wt% γ-alumina, and is applied to the back surface of the dielectric multilayer thin film formed on the back surface of the light-transmitting window of the lid. The color conversion member is constituted by heating and curing for 30 minutes. After sufficiently removing moisture in the recess of the package, the recess is sealed with a Kovar lid having a glass window at the center, and seam welding is performed to form a light emitting device. The light emitting device thus obtained is highly reliable and can emit light with high output, and white light with chromaticity coordinates (x, y) = (0.384, 0.332) can be obtained. .
[0090]
  (Reference Example 7) Instead of the dielectric multilayer thin film, light was emitted in the same manner as in Example 6 except that a glass layer made of Pb capable of substantially absorbing ultraviolet light and substantially transmitting visible light was formed. When the device is formed, although the luminance is lower than that of Reference Example 6, the reliability is improved. Here, the material of the glass layer is not particularly limited as long as it can substantially absorb light in the ultraviolet region and substantially transmit visible light.
[0091]
  Reference Example 8 A light emitting device is formed in the same manner as in Example 3 except that a nitride semiconductor element having a 375 nm GaN semiconductor is electrically connected to a metal package as an LED chip. In the upper surface direction, which is the main surface side of the transparent window portion of the lid of the light emitting device thus obtained, contains the same fluorescent material as in Reference Example 6 and has TiO on the upper surface side as shown in the reference example of FIG.₂/ SiO₂A color conversion member having a dielectric multilayer thin film made of is fixed with low melting point glass.
[0092]
  Here, a method of forming the color conversion member will be described. First, a mixture of glass and a fluorescent material is cured into a rod shape. The rod is cut into a preferable film thickness according to the desired color tone of the light, arranged in a vacuum vapor deposition apparatus, and a dielectric multilayer thin film is formed on the cut surface on the upper surface side. On the other hand, a reflective thin film capable of satisfactorily reflecting both ultraviolet rays and visible light may be provided on the surfaces other than the upper surface, that is, the bottom surface and the side surface, thereby further improving the output. However, when the reflective thin film is provided on the bottom surface, it is not formed on the entire surface, but is formed with an opening for introducing the excitation light from the light emitting element.
[0093]
  The light-emitting device thus obtained provides the same effects as in Reference Example 6 and a light-emitting device with excellent mass productivity.
【The invention's effect】
The light emitting device of the present invention can maintain reliability without deterioration even when a large current is applied by using a highly reliable metal package, and is excellent in mass productivity. Thereby, it is possible to realize a light-emitting device that is highly reliable and can emit light having the same brightness as that of illumination and has excellent mass productivity.
[Brief description of the drawings]
FIG. 1 is a schematic plan view and a schematic cross-sectional view showing a reference example of a light emitting device of the present invention.
FIG. 2 is a schematic plan view and a schematic cross-sectional view showing a reference example of the present invention.
FIG. 3 is a schematic cross-sectional view showing a reference example of the present invention.
FIG. 4 is a schematic cross-sectional view showing a reference example of the present invention.
FIG. 5 is a schematic cross-sectional view showing a reference example of the present invention.
FIG. 6 is a schematic cross-sectional view showing a light emitting device of the present invention.
FIG. 7 is a schematic cross-sectional view showing another light emitting device of the present invention.
FIG. 8 is a schematic cross-sectional view showing a reference example of the present invention.
FIG. 9 is a schematic cross-sectional view showing a reference example of the present invention.
FIG. 10 is a schematic cross-sectional view showing a reference example of the present invention.
FIG. 11 is a schematic cross-sectional view showing a reference example of the present invention.
FIG. 12 is a schematic cross-sectional view showing a reference example of the present invention.
FIG. 13 is a schematic cross-sectional view of a light emitting device shown for comparison with the present invention.
FIG. 14 is a schematic cross-sectional view of a light emitting device shown for comparison with the present invention.
[Explanation of symbols]
1. Light emitting element
2 ... Lead electrode
3. Insulating member
4 ... Wire
5 ...package
6 ... Lid
7 ... Window
8 ... Fluorescent substance
9 ... Mold resin
10 ... Metal base
11 ... Can with window
12 ... Buttocks
13. Color conversion member
14 ... Dielectric multilayer thin film
15 ... Adhesive member

Claims (1)

A light emitting element;
A metal package having a recess for accommodating the light emitting element;
A lid that seals the metal package and has a light-transmitting window;
A surface-mounted light emitting device having:
The metal package has a flange on the outer side of the recess,
The lid has a plane upper surface facing said flange portion, and a central portion having a recess and symmetrically convex portion of the package, a window portion of the central portion is glass, the convex on its inside A surface-mounted light-emitting device having a color conversion member having a thickness equal to or less than a thickness of a portion .

Images