JPWO2012086483A1 - Phosphor coating device and method for manufacturing light emitting device - Google Patents

Abstract

When forming a phosphor dispersion film by spraying, it is possible to form a phosphor dispersion film having a uniform film thickness with little density unevenness, and obtain a phosphor coating device that does not solidify due to the phosphor remaining at the tip of the spray nozzle For this purpose, the light emitting surface of the LED light emitting element 3 is faced downward, the spray nozzle 14 is disposed on the lower side of the LED light emitting element, and the phosphor mixed solution 20 is sprayed upward from the spray nozzle, so that the phosphor is applied to the light emitting surface. The phosphor coating apparatus 10 was configured to apply the mixed liquid. In addition, as a manufacturing method of a light emitting device including an upward coating process in which the phosphor mixed solution 20 is blown upward from the spray nozzle 14 and the phosphor mixed solution 20 is applied to the light emitting surface using this phosphor coating device. An LED light source having a phosphor dispersion film having a uniform film thickness with little unevenness can be manufactured.

Description

  The present invention relates to a light-emitting device having a light-emitting element and a wavelength conversion unit including a phosphor that converts the wavelength of light emitted from the light-emitting element. The present invention relates to a method for manufacturing a light emitting device using a phosphor coating device.

  Conventionally, a light-emitting device (LED light source) including an LED light-emitting element that emits light of a predetermined color and a wavelength conversion unit in which a phosphor that converts light emitted from the LED light-emitting element into light of a desired color is dispersed is known. ing.

  For example, a phosphor such as a YAG phosphor is disposed in the vicinity of a gallium nitride (GaN) -based blue LED (Light Emitting Diode) chip, and the blue light emitted from the blue LED chip and the phosphor is blue light. In general, a technique for obtaining a white LED by mixing with yellow light emitted by secondary light emission in response to the light is widely used.

  At this time, in order to obtain white light emission with a uniform color tone, a phosphor dispersed glass (wavelength conversion unit) in which a phosphor is uniformly dispersed in a transparent resin is used, and an LED light emitting element is formed in this film material. Therefore, it is important to uniformly mix blue light emitted from the fluorescent material and yellow light emitted from the phosphor so as to uniformly emit white light that is mixed color light outside the glass body.

  The wavelength converter (phosphor-dispersed glass) can be created, for example, by mixing glass powder and phosphor powder, adding a resin binder, press-molding it into a predetermined shape, and firing it. In addition, a phosphor dispersion liquid (wavelength conversion portion) having a predetermined thickness may be formed by spray-coating a liquid phosphor mixture produced by blending phosphor powder with alcohol or a resin binder and then curing the mixture. it can.

  For example, a light emitting diode package structure in which a phosphor layer is formed by spray coating a phosphor mixed solution obtained by mixing phosphor powder in a predetermined solvent and a method for manufacturing the same have already been proposed (see, for example, Patent Document 1).

JP 2010-226110 A

  As described above, the phosphor dispersion film can be formed by a spray method. Moreover, when applying (coating) the phosphor dispersion film by the spray method, generally, a spray nozzle is disposed on the LED light emitting element, and the phosphor mixture is sprayed downward from the spray nozzle. It is configured to do.

  In this case, the mist of the phosphor mixture liquid sprayed from the spray nozzle adheres to the surface of the LED light emitting element, but in addition to this, the mist that floats and falls in the air is delayed on the surface of the LED light emitting element. May adhere.

  The mist that floats and falls in the air is affected by the temperature in the spray coating device and the flow of air. This is not preferable because it causes uneven thickness of the dispersion film.

  When uneven density of the phosphor or uneven thickness of the phosphor dispersion film occurs, unevenness occurs in the rate of conversion of the color emitted from the LED light emitting element, and a uniform emission color cannot be obtained and chromaticity is not obtained. Change will be a problem.

  In addition, when spray application is stopped, the phosphor mixture remaining at the tip of the spray nozzle gathers at the tip and becomes a ball, and the solvent (for example, alcohol) in the mixture evaporates and the phosphor solidifies. It causes nozzle clogging and becomes a problem.

  Therefore, even if the phosphor dispersion liquid is formed on the LED light emitting device by applying the phosphor mixture liquid using a spray nozzle, the spray is not affected by the mist that floats in the air and falls. There is a need for a phosphor coating apparatus in which phosphor remains at the tip of the nozzle and does not solidify. Moreover, it is required to manufacture an LED light source having a phosphor dispersion film with a uniform film thickness using this phosphor coating apparatus.

  Therefore, in the present invention, when forming a phosphor dispersion film by the spray method, it is possible to form a phosphor dispersion film having a uniform film thickness with little density unevenness, and the phosphor remains at the tip of the spray nozzle and does not solidify. It is an object of the present invention to provide a body coating apparatus, and to provide a method for manufacturing a light emitting apparatus capable of manufacturing an LED light source having a phosphor dispersion film having a uniform film thickness with little density unevenness using the phosphor coating apparatus. .

  In order to achieve the above object, the present invention is a phosphor coating apparatus used for manufacturing a light emitting device having a light emitting element and a wavelength conversion unit including a phosphor that converts the wavelength of light emitted from the light emitting element. The light emitting element is an LED light emitting element, and a phosphor mixed liquid in which a predetermined phosphor is dispersed is applied to a light emitting surface of the LED light emitting element mounted on an LED substrate by a spray means, and the LED The light emitting surface of the light emitting element faces downward, and a spray nozzle is disposed below the LED light emitting element, and the phosphor mixed liquid is sprayed upward from the spray nozzle, and the phosphor mixed liquid is applied to the light emitting surface. It is characterized by doing.

  According to said structure, since a fluorescent substance liquid mixture is sprayed and applied upwards, the mist which floats in the air falls naturally and does not adhere to a light emitting surface. Therefore, only the phosphor mixture liquid sprayed upward adheres to the light emitting surface, and it becomes possible to form a phosphor dispersion film having a uniform film thickness with little density unevenness. Further, since the spray nozzle is disposed upward, the phosphor is prevented from remaining at the tip of the nozzle, and the phosphor coating apparatus does not remain and solidify.

  Further, the present invention is the phosphor coating apparatus having the above-described configuration, wherein the phosphor coating apparatus stores an LED support portion that supports the LED substrate with a light emitting surface of the LED light emitting element facing downward, and the phosphor mixed solution. A tank, the spray nozzle, and a pipe for feeding the phosphor mixture stored in the tank to the spray nozzle are provided. According to this configuration, the phosphor mixed liquid stored in the tank can be easily applied to the LED support portion by using the spray nozzle that attaches the LED substrate with the light emitting surface facing downward and sprays upward.

  Further, the present invention is characterized in that, in the phosphor coating apparatus having the above-described configuration, the spray angle of the spray nozzle is upward in the vertical direction or upward in a diagonally upward range inclined by a predetermined angle from the vertical direction. According to this configuration, the phosphor mixture is sprayed vertically upward or obliquely upward, so that the phosphor dispersion film having a uniform film thickness with little unevenness in density is not affected by mist floating in the air. It can be formed.

  In the phosphor coating apparatus having the above-described configuration, the LED support portion can displace the LED substrate in a vertically downward direction with the light emitting surface inclined in a vertically downward direction and a diagonally downward direction inclined by a predetermined angle from the vertically downward direction. It is characterized by that. According to this configuration, the support posture of the LED substrate can be changed according to the shape of the light emitting surface on which the phosphor mixture is applied. Therefore, it is possible to obtain a phosphor coating apparatus that can easily adapt to various shapes and can apply the phosphor.

  In the phosphor coating apparatus configured as described above, the predetermined angle is at most 75 degrees. According to this configuration, by adopting a configuration that is inclined at most 75 degrees from the vertical direction, it is possible to form a phosphor dispersion film having a uniform film thickness with little density unevenness corresponding to a light emitting device having a light emitting surface of various shapes. Thus, a phosphor coating apparatus can be obtained in which the phosphor remains at the tip of the spray nozzle and does not solidify.

  Further, the present invention is a method of manufacturing a light emitting device having a light emitting element and a wavelength conversion unit including a phosphor that converts the wavelength of light emitted from the light emitting element, wherein the light emitting element is an LED light emitting element, Using a spray nozzle, a phosphor coating step of applying a phosphor mixed liquid in which a predetermined phosphor is dispersed on the light emitting surface of the LED light emitting element mounted on the LED substrate, and the phosphor mixed liquid applied And firing the phosphor to form the phosphor dispersion film to form the wavelength conversion portion, and the phosphor coating step sprays the phosphor mixture liquid upward from the spray nozzle, and the light emitting surface. It is characterized by being an upward coating process in which the phosphor mixed solution is coated.

  With the above configuration, since the phosphor mixture is sprayed upward from the spray nozzle, it is possible to form a phosphor dispersion film with a uniform film thickness with little density unevenness without being affected by mist floating in the air. Manufacturing method.

  In the method for manufacturing a light emitting device having the above-described configuration, the spray angle of the spray nozzle in the upward coating step is upward in the vertical direction or upward in a diagonally upward range inclined by a predetermined angle from the vertical direction. It is characterized by. According to this configuration, since the phosphor mixed solution is sprayed vertically upward or obliquely upward, a coating film having a predetermined thickness can be formed without being affected by mist floating in the air.

  According to the present invention, in the method for manufacturing a light emitting device having the above-described configuration, the predetermined angle is at most 75 degrees. According to this configuration, the spray angle of the spray nozzle is inclined at most 75 degrees from the vertical direction, thereby forming a phosphor dispersion film with a uniform film thickness corresponding to a light emitting device having a light emitting surface of various shapes. This is a possible method for manufacturing a light emitting device.

  According to the present invention, since the phosphor mixed solution is sprayed upward and applied, the mist floating in the air naturally falls and does not adhere to the light emitting surface, but only the phosphor mixed solution sprayed upward is the light emitting surface. It is possible to obtain a phosphor coating apparatus capable of forming a phosphor dispersion film having a uniform film thickness with little density unevenness. For this reason, it is possible to reduce the unevenness of coating of the phosphor dispersion film and suppress the change in chromaticity. In addition, according to the method for manufacturing a light emitting device according to the present invention using this phosphor coating apparatus, it is possible to manufacture an LED light source having a phosphor dispersion film having a uniform film thickness with little density unevenness.

It is a schematic explanatory drawing which shows the structure of the fluorescent substance coating device which concerns on this invention. It is sectional drawing which shows schematic structure of the light-emitting device which concerns on this invention. It is a schematic explanatory drawing of 1st embodiment which apply | coats fluorescent substance. It is a schematic explanatory drawing of 2nd embodiment which apply | coats fluorescent substance.

  Embodiments of the present invention will be described below with reference to the drawings. Moreover, the same code | symbol is used about the same structural member, and detailed description is abbreviate | omitted suitably.

  First, the phosphor coating apparatus according to this embodiment will be described with reference to FIG. The phosphor coating apparatus 10 according to the present embodiment is an apparatus that coats the phosphor mixed solution 20 on the LED light emitting elements 3 mounted on the LED substrate 1 using a spray unit, and stores the phosphor mixed solution 20. A tank 11, a spray nozzle 14 as a spray means, and a pipe 13 for feeding the phosphor mixture 20 from the tank 11 to the spray nozzle 14 are provided. Further, the phosphor mixed solution 20 sprayed and applied from the spray nozzle 14 is baked to generate a wavelength conversion unit, and the phosphor dispersion film 6 (a predetermined phosphor is dispersed on the light emitting surface of the LED light emitting element 3). A light emitting device LD (LED light source; see FIG. 2) having a wavelength conversion unit) is manufactured.

  The tank 11 has a stirring mechanism 12. The stirring mechanism 12 has a function of stirring and uniformly mixing the phosphor mixed solution 20 in which a phosphor or inorganic fine particles are mixed in an organic solvent. For example, the stirring mechanism 12 is disposed in the tank 11 via magnetic force or electric force. The configuration is not particularly limited as long as the movable blade-shaped movable piece is driven.

  The phosphor mixed liquid 20 uniformly mixed through the stirring mechanism 12 is pressurized and supplied from the tank 11 to the spray nozzle 14 through the pipe 13 and receives the wind pressure to spray the application target from the spray nozzle tip 14a. Applied. At this time, an opening that can be freely opened and closed is provided at the tip of the spray nozzle 14, and the opening and closing operation is performed to control the on / off of the spraying operation.

  In addition, the phosphor coating apparatus 10 according to the present embodiment faces the light emitting surface of the LED light emitting element 3 downward in order to reduce the density unevenness of the phosphor in the phosphor dispersion film 6 and suppress the variation in light emission chromaticity. Then, the LED substrate 1 is held via the LED support portion 15 and the phosphor mixed solution is sprayed upward from the spray nozzle 14 disposed below the light emitting surface, so that the phosphor mixed solution 20 is uniformly applied to the light emitting surface. It is set as the structure apply | coated to.

  The phosphor mixed solution 20 contains, for example, a phosphor, a layered silicate mineral, and inorganic fine particles in a sol-like mixed solution obtained by mixing an organometallic compound in an organic solvent. The organometallic compound serves as a binder that seals the phosphor, the layered silicate mineral, and the inorganic fine particles. Examples of the organometallic compound used in the present embodiment include metal alkoxides, metal acetylacetonates, metal carboxylates, and the like, and metal alkoxides that are easily gelled by hydrolysis and polymerization reaction are preferable.

  The metal alkoxide may be a single molecule such as tetraethoxysilane, or may be a polysiloxane in which an organic siloxane compound is linked in a chain or a ring, but a polysiloxane that increases the viscosity of the mixed solution is preferable. In addition, there is no restriction | limiting in the kind of metal if a translucent glass body can be formed, but it is preferable to contain a silicon | silicone from a viewpoint of the stability of the glass body formed and the ease of manufacture. Moreover, you may contain multiple types of metal.

  The phosphor is excited by the wavelength (excitation wavelength) of the emitted light from the LED light emitting element 3, and emits fluorescence having a wavelength different from the excitation wavelength. In this embodiment, a YAG (yttrium, aluminum, garnet) phosphor that converts blue light (wavelength 420 nm to 485 nm) emitted from the blue LED element into yellow light (wavelength 550 nm to 650 nm) is used.

  Such phosphors use oxides of Y, Gd, Ce, Sm, Al, La, and Ga, or compounds that easily become oxides at high temperatures, and are mixed well in a stoichiometric ratio. A mixed raw material is obtained. Alternatively, a coprecipitated oxide obtained by calcining a solution obtained by coprecipitation of a solution obtained by dissolving a rare earth element of Y, Gd, Ce, or Sm in an acid with a stoichiometric ratio with oxalic acid, and aluminum oxide or gallium oxide. Mix to obtain a mixed raw material. Then, an appropriate amount of fluoride such as ammonium fluoride is mixed with the obtained mixed raw material as a flux and pressed to obtain a molded body. The obtained molded body is packed in a crucible and fired in air at a temperature range of 1350 to 1450 ° C. for 2 to 5 hours to obtain a sintered body having phosphor emission characteristics. Next, the fired product is ball milled in water, washed, separated and dried, and finally passed through a sieve to obtain a desired phosphor.

  Further, the composition of the obtained phosphor was examined to confirm that it was a desired phosphor, and the emission wavelength in the excitation light of 465 nm was examined. As a result, it was confirmed that the peak wavelength was approximately 570 nm. That is, a phosphor that emits yellow light when irradiated with blue light can be obtained.

  In this embodiment, the YAG phosphor is used. However, the type of the phosphor is not limited to this. For example, other phosphors such as non-garnet phosphors containing no Ce are used. You can also. In addition, the larger the particle size of the phosphor, the higher the light emission efficiency (wavelength conversion efficiency). On the other hand, the gap formed at the interface with the organometallic compound is increased, and the film strength of the formed ceramic layer is lowered. Accordingly, in consideration of the size of the gap generated at the interface between the light emission efficiency and the organometallic compound, it is preferable to use one having an average particle diameter of 1 μm or more and 50 μm or less. The average particle diameter of the phosphor can be measured, for example, by a Coulter counter method.

  The layered silicate mineral is preferably a swellable clay mineral having a structure such as a mica structure, a kaolinite structure, or a smectite structure, and particularly preferably a smectite structure rich in swellability. This is because, as will be described later, by adding water to the mixed liquid, it takes a card house structure in which water enters and swells between the layers of the smectite structure, so the viscosity of the mixed liquid is greatly increased. It is.

  When the content of the layered silicate mineral in the ceramic layer is less than 0.5% by weight, the effect of increasing the viscosity of the mixed solution cannot be obtained sufficiently. On the other hand, when the content of the layered silicate mineral exceeds 20% by weight, the strength of the ceramic layer after heating is lowered. Therefore, the content of the layered silicate mineral is preferably 0.5% by weight or more and 20% by weight or less, and more preferably 0.5% by weight or more and 10% by weight or less.

  In consideration of compatibility with an organic solvent, a layered silicate mineral whose surface is modified (surface treatment) with an ammonium salt or the like can be used as appropriate.

  Inorganic fine particles include a filling effect that fills gaps formed at the interface between the organometallic compound, the phosphor and the layered silicate mineral, a thickening effect that increases the viscosity of the mixed solution before heating, and a ceramic layer film after heating. It has a film strengthening effect that improves strength. Examples of the inorganic fine particles used in the present invention include oxide fine particles such as silicon oxide, titanium oxide and zinc oxide, and fluoride fine particles such as magnesium fluoride. In particular, when a silicon-containing organic compound such as polysiloxane is used as the organometallic compound, it is preferable to use silicon oxide fine particles from the viewpoint of stability with respect to the formed ceramic layer.

  When the content of the inorganic fine particles in the ceramic layer is less than 0.5% by weight, the above-described effects cannot be sufficiently obtained. On the other hand, if the content of the inorganic fine particles exceeds 50% by weight, the strength of the ceramic layer after heating is lowered. Therefore, the content of the inorganic fine particles in the ceramic layer is preferably 0.5 wt% or more and 50 wt% or less, and more preferably 1 wt% or more and 40 wt% or less. The average particle diameter of the inorganic fine particles is preferably 0.001 μm or more and 50 μm or less in consideration of the above-described effects. The average particle diameter of the inorganic fine particles can be measured, for example, by a Coulter counter method.

  In consideration of compatibility with an organic metal compound or an organic solvent, a material obtained by treating the surface of inorganic fine particles with a silane coupling agent or a titanium coupling agent can be used as appropriate.

  A translucent ceramic layer can be obtained by heating a precursor solution obtained by mixing an organometallic compound in an organic solvent. A phosphor dispersion film (wavelength conversion unit) is formed by applying and heating a phosphor mixed solution obtained by mixing phosphor, layered silicate mineral, and inorganic fine particles to the precursor solution. Furthermore, by adding water to the mixed solution, water enters between the layers of the layered silicate mineral and the viscosity of the mixed solution increases, so that the phosphor can be prevented from settling. In addition, since there exists a possibility of inhibiting a polymerization reaction when the impurity is contained in water, it is necessary to use the pure water which does not contain an impurity for the water to add.

  As the organic solvent, alcohols such as methanol, ethanol, propanol and butanol having excellent compatibility with added water are preferable. Further, when the amount of the organometallic compound mixed with the organic solvent is less than 5% by weight, it becomes difficult to increase the viscosity of the mixed solution, and when the amount of the organometallic compound exceeds 50% by weight, the polymerization reaction is faster than necessary. Proceed. Therefore, the amount of the organometallic compound mixed with the organic solvent is preferably 5% by weight or more and 50% by weight or less, and more preferably 8% by weight or more and 40% by weight or less.

  For example, when using a surface-treated lipophilic layered silicate mineral, the layered silicate mineral is first added to a solution (precursor solution) in which an organometallic compound is mixed in an organic solvent. Premixing is performed, and then phosphor, inorganic fine particles, and water are mixed. When a hydrophilic layered silicate mineral that has not been surface-treated is used, first the layered silicate mineral and water are premixed, and then the phosphor, inorganic fine particles, and precursor solution are mixed. Thereby, a layered silicate mineral can be mixed uniformly and the thickening effect can be heightened more. The preferred viscosity of the mixed solution is 25 to 800 cP, and the most preferred viscosity is 30 to 500 cP.

  Further, when the ratio of water to the total amount of the solvent obtained by adding water to the organic solvent is less than 5% by weight, the above thickening effect cannot be sufficiently obtained, and when the ratio of water exceeds 60% by weight, the thickening effect The effect of reducing the viscosity due to excessive mixing of water is greater than that. Therefore, the ratio of water is preferably 5% by weight or more and 60% by weight or less, and more preferably 7% by weight or more and 55% by weight or less with respect to the total amount of solvent.

  The most preferable composition of the mixed liquid is one using polysiloxane as the organometallic compound, and the most preferable composition range of each of the above components contained in the mixed liquid is that the polysiloxane dispersion is 4 to 30% by weight, and the layered silica is used. The acid salt mineral is 1 to 10% by weight, the inorganic fine particles are 1 to 40% by weight, and the water is 10 to 50% by weight.

  Moreover, in the above-mentioned phosphor mixed solution, a phosphor mixed solution containing a phosphor, a layered silicate mineral, and inorganic fine particles is used as a sol-like mixed solution obtained by mixing an organometallic compound as a ceramic material in an organic solvent. Although the structure is described, a ceramic layer containing a phosphor is formed by separately preparing a mixed solution containing phosphor particles and a mixed solution containing an organometallic compound and firing each of them after application. Also good.

  Since the dispersion liquid containing phosphor particles may lose dispersion uniformity over time due to sedimentation of the phosphor particles, the dispersion stability is enhanced by additives such as inorganic particles and layered silicate minerals. There is a need. Moreover, the viscosity of a liquid mixture is kept high with these additives.

  For this reason, if the mixed solution contains an organometallic compound that is a ceramic material, the reaction proceeds at the time of storage, whereby the viscosity increases and the applicability may deteriorate. In addition, the reaction of the ceramic material is generally an irreversible reaction, and when the reaction of the organometallic compound that is the ceramic material proceeds in the mixed solution containing the phosphor particles, the mixture containing the phosphor particles is mixed. All liquids may become unusable. For this reason, the mixed liquid is divided into two or more mixed liquids according to the components and applied, so that the storage stability is improved and expensive phosphor particles are wasted even when the reaction of the ceramic material proceeds. This is the preferred form because it does not.

  In the case of applying using two or more mixed liquids, the amount of the organometallic compound serving as a ceramic material such as polysiloxane in the mixed liquid containing the phosphor particles is preferably 1% by weight or less. More preferably, it is more preferably 5% by weight or less, and particularly preferably not contained.

  When two liquids are sequentially applied by spraying, it is preferable to apply a mixed liquid containing an organometallic compound that is a ceramic material after applying a mixed liquid containing phosphor particles. Before applying the liquid mixture containing phosphor particles, apply the liquid mixture containing ceramic material, apply the liquid mixture containing phosphor particles, and then apply the liquid mixture containing ceramic material again. Also good. Moreover, you may spray-coat these liquid mixture simultaneously.

  In any case, in order to obtain the effect of the present invention, the liquid mixture containing the phosphor particles needs to be applied upward. About the liquid mixture containing a ceramic material, you may apply | coat upwards and may apply | coat downwards.

  A predetermined amount of the phosphor mixture 20 obtained as described above is applied to the LED light emitting element 3, and heated and baked to form a phosphor dispersion film 6 (wavelength conversion portion) having a predetermined thickness. When the heating temperature is less than 100 ° C., the polymerization reaction of the organometallic compound does not proceed. When the heating temperature exceeds 1000 ° C., the layered silicate mineral is thermally decomposed and the layered structure is destroyed. Therefore, the heating temperature of the mixed liquid needs to be 100 ° C. or higher and 1000 ° C. or lower, and is preferably 250 ° C. to 600 ° C.

  Further, when the thickness of the formed phosphor dispersion film 6 (wavelength conversion portion) is less than 5 μm, the wavelength conversion efficiency is lowered and sufficient fluorescence cannot be obtained, and the thickness of the phosphor dispersion film 6 exceeds 500 μm. In such a case, the film strength is lowered and cracks and the like are likely to occur. Therefore, the thickness of the phosphor dispersion film 6 is preferably 5 μm or more and 500 μm or less.

  The light emitting device LD manufactured as described above will be described with reference to FIG.

  As shown in FIG. 2, in the light emitting device LD, a metal part 2 is provided on an LED substrate 1 having a concave cross section, and an LED light emitting element 3 is arranged on the metal part 2. The LED light emitting element 3 is provided with a protruding electrode 4 on the surface facing the metal part 2, and the metal part 2 and the LED light emitting element 3 are connected via the protruding electrode 4 (flip chip type). In addition, the structure which provides one LED light emitting element 3 with respect to one LED board 1, or the structure which provides several LED light emitting element 3 with respect to one LED board may be sufficient.

  In the present embodiment, a blue LED element is used as the LED light emitting element 3. The blue LED element is formed, for example, by laminating an n-GaN-based cladding layer, an InGaN light-emitting layer, a p-GaN-based cladding layer, and a transparent electrode on a sapphire substrate.

  In addition, a phosphor dispersion film 6 (wavelength conversion unit) is formed in the concave portion of the LED substrate 1 so as to seal the periphery of the LED light emitting element 3. The phosphor dispersion film 6 (wavelength conversion unit) is a part that converts light having a predetermined wavelength emitted from the LED light emitting element 3 into light having a different wavelength, and the LED light emitting element 3 is included in the translucent ceramic layer. A predetermined phosphor that is excited by the wavelength of the light and emits fluorescence having a wavelength different from the excitation wavelength is added.

  The phosphor dispersion film 6 (wavelength conversion unit) may be provided at least around the LED light emitting element 3 (upper surface and side surface), and may not be provided in the other concave portion of the LED substrate 1. In addition, as a method of providing the phosphor dispersion film 6 (wavelength conversion unit) only around the LED light emitting element 3, a method of masking other than the periphery of the LED light emitting element 3 can be used.

  In the present embodiment, as shown in FIG. 1, the light emitting surface of the LED light emitting element 3 faces downward, the spray nozzle 14 is disposed below the LED light emitting element 3, and the above-mentioned predetermined upward from the spray nozzle 14. The phosphor mixed solution 20 containing the phosphor is sprayed.

  That is, the phosphor coating apparatus 10 is a phosphor coating apparatus that coats the phosphor mixed liquid 20 in which a predetermined phosphor is dispersed by spray means, and the LED substrate 1 with the light emitting surface of the LED light emitting element 3 facing downward. LED supporting portion 15 for supporting the liquid, tank 11 for storing the phosphor mixture liquid 20, spray nozzle 14 serving as a spray means, and piping for feeding the phosphor mixture liquid 20 stored in the tank 11 to the spray nozzle 14 13.

  Further, the tank 11 has a stirring mechanism 12, and the phosphor mixed solution 20 uniformly mixed through the stirring mechanism 12 is supplied with pressure to the spray nozzle 14 from the tank 11 through the pipe 13. In response to the wind pressure, it is sprayed upward from the tip of the spray nozzle and sprayed onto the object to be coated.

  With the phosphor coating apparatus 10 having the above-described configuration, the phosphor mixed solution 20 in which the phosphors are uniformly mixed is generated and applied by spraying upward from the spray nozzle 14, so that the mist floating in the air is natural. It falls and does not adhere to the light emitting surface. Therefore, only the phosphor mixture 20 sprayed upward adheres to the light emitting surface, and it becomes possible to form the phosphor dispersion film 6 having a uniform film thickness with little density unevenness.

  When the phosphor dispersion film 6 has little density unevenness and the film thickness is uniform, it means that there is little coating unevenness of the phosphor dispersion film 6, so that the phosphor is uniformly dispersed to develop uniform fluorescence. It becomes a structure and the change of chromaticity can be suppressed. Further, since the spray nozzle 14 is disposed upward, it is preferable to provide the phosphor coating apparatus 10 in which the phosphor is prevented from remaining at the tip of the nozzle and the phosphor remains and does not solidify.

  If the phosphor dispersion film in which the phosphor is uniformly dispersed is formed to a predetermined thickness, the third light in which the primary light emitted from the light emitting element and the secondary light emitted from the phosphor are uniformly mixed is used. It emits light, can suppress the change in emission chromaticity, and can manufacture a high-quality light-emitting device (LED light source). That is, by using the phosphor coating apparatus 10 of this embodiment, it is possible to manufacture a high-quality light-emitting device LD having a phosphor dispersion film in which phosphors are uniformly dispersed.

  The meaning of spraying the phosphor mixture liquid upward using the spray nozzle 14 is not limited to the configuration of spraying upward in the vertical direction, and may be obliquely upward so as not to be affected by mist floating in the air. For example, it may be up to about 75 degrees obliquely. Moreover, it is good also as a structure which inclined the LED substrate side which is a to-be-coated body.

  Next, a specific configuration example in which the phosphor mixed solution is sprayed upward will be described with reference to FIGS. 3 and 4. FIG. 3 shows a first embodiment in which the spray nozzle is configured to be movable in the vertical direction and obliquely upward, and FIG. 4 shows a second embodiment in which the LED substrate side that is an object to be coated is inclined.

  For example, the spray nozzle 14 may be a phosphor such as a spray nozzle 14A sprayed upward in the vertical direction indicated by a solid line in FIG. It is set as the structure which sprays a liquid mixture upwards.

  The spray nozzle 14A sprays the phosphor mixture liquid so as to face the light emitting surface 3a of the LED light emitting element 3, and the spray nozzle 14B mixes the phosphor toward the angle at which the light emitting surface 3a and the side surface 3b intersect and toward the side surface 3b. The liquid is sprayed, and the spray nozzle 14C sprays the phosphor mixed liquid toward the corner where the light emitting surface 3a and the side surface 3c intersect and the side surface 3c.

  As described above, in the present embodiment, the angle at which the phosphor mixture is blown upward from the spray nozzle 14 is upward in the vertical direction or upward in a diagonally upward range inclined by a predetermined angle from the vertical direction. If it is this structure, the light emission surface 3a and the side surfaces 3b and 3c of the light emitting element 3 are not affected by the mist which floats in the air by spraying a fluorescent substance liquid mixture vertically upward or diagonally upward. It is possible to form a phosphor dispersion film having a uniform film thickness on the entire circumference.

  Further, the predetermined angle of spraying upward from the spray nozzle 14 is set to be within 75 degrees, that is, at most 75 degrees so that the phosphor mixed solution can be sprayed without being affected by the mist floating in the air. With such a configuration, the spray nozzle 14 is inclined at most 75 degrees from the vertical direction, so that a phosphor dispersion film having a uniform film thickness can be formed corresponding to a light emitting device having a light emitting surface of various shapes. A phosphor coating apparatus that can be formed and does not solidify due to the phosphor remaining at the tip of the spray nozzle can be obtained.

  Moreover, it is good also as a structure which changes to the attitude | position of the light emission surface of an LED light emitting element instead of the spray nozzle 14, for example, makes the LED support part 15 tiltable, and the support attitude | position of an LED board is displaced. That is, as shown in FIG. 4, the LED substrate 1A is inclined at a predetermined angle, and the phosphor mixed solution 20 is sprayed upward on the LED light emitting element 3 mounted on the LED substrate 1A using, for example, a spray nozzle 14A.

  That is, the LED support portion 15 can displace the LED substrate 1 in the vertically downward direction and the obliquely downward direction in which the light emitting surface of the LED light emitting element 3 to be mounted is inclined at a predetermined angle from the vertically downward direction. In this case, the predetermined angle is at most about 75 degrees. If it is such a structure, according to the shape of the light emission surface which apply | coats the phosphor liquid mixture 20, the support attitude | position of the LED board 1 can be changed. Therefore, it is possible to obtain a phosphor coating apparatus that can easily adapt to various shapes and can apply the phosphor.

  Moreover, it is good also as a structure which inclines both the spray nozzle 14 and the LED board 1, and sprays the fluorescent substance liquid mixture 20 upwards, According to the shape of a LED board, the shape of a LED light emitting element, the shape of a light emission surface, etc. The first method for inclining the spray nozzle 14 and the second method for inclining the LED substrate 1 are appropriately selected and used in appropriate combination.

<Experimental example>
Next, the results of experiments actually performed will be described. In this experiment, a blue LED element is used as a light emitting element, and a YAG phosphor that converts blue light into yellow light (wavelength 550 nm to 650 nm) is formed on the light emitting surface. Further, as described in the first embodiment, the phosphor mixture is sprayed upward on the light emitting surface 3a of the LED light emitting element 3 by the spray nozzle 14A, and the angle at which the light emitting surface 3a and the side surface 3b intersect by the spray nozzle 14B, The phosphor mixed liquid is sprayed toward the side surface 3b, and the phosphor mixed liquid is sprayed toward the corner where the light emitting surface 3a and the side surface 3c intersect and the side surface 3c by the spray nozzle 14C. In this manner, a light emitting device as an experimental example was manufactured, and the light emission chromaticity was confirmed. In addition, as a comparative example, a light emitting device in which a phosphor dispersion film was formed by a conventional method in which a phosphor mixed solution was sprayed downward from a spray nozzle was manufactured, and the emission chromaticity was confirmed. The experimental results are shown in Table 1.

  As shown in Table 1, using a light emitting device that emits white light by forming a yellow phosphor dispersion film on a blue LED element, the hue (light emission chromaticity) was visually confirmed. In the comparative example to be sprayed (conventional example), it was clarified that the hue was certainly not uniform but slightly changed. However, according to the experimental example sprayed upward from the spray nozzle, no change in chromaticity was observed, and it was confirmed that the change in chromaticity was smaller than that in the comparative example.

  Next, a method for manufacturing the light emitting device according to this embodiment will be described.

  The method for manufacturing a light emitting device according to the present embodiment is a method for manufacturing a light emitting device having a light emitting element and a wavelength conversion unit including a phosphor that converts the wavelength of light emitted from the light emitting element. In addition, the light emitting element is an LED light emitting element, and a phosphor application step of applying a phosphor mixed liquid in which a predetermined phosphor is dispersed to the light emitting surface of the LED light emitting element mounted on the LED substrate using a spray nozzle. And a firing step of firing the applied phosphor mixed solution to form a phosphor dispersion film to form a wavelength conversion section.

  Moreover, in this embodiment, a fluorescent substance application process is an upward application process which blows out a fluorescent substance liquid mixture upwards from a spray nozzle, and applies a fluorescent substance liquid mixture to the light emission surface of a LED light emitting element.

  With the above configuration, since the phosphor mixed solution is sprayed upward from the spray nozzle, it is possible to form a phosphor dispersion film having a uniform film thickness with little density unevenness without being affected by mist floating in the air. It is preferable as a manufacturing method.

  Moreover, it is preferable that the spray angle of the spray nozzle in the upward coating process is upward in the vertical direction or upward in a diagonally upward range inclined by a predetermined angle from the vertical direction. With such a configuration, the phosphor mixture is sprayed vertically upward or obliquely upward, so that a coating film having a predetermined thickness with little concentration unevenness is formed without being affected by mist floating in the air. can do.

  The predetermined angle is preferably at most 75 degrees as described above. With such a configuration, the spray angle of the spray nozzle is inclined at most 75 degrees from the vertical direction, so that the phosphor dispersion with a uniform film thickness can be applied to light emitting devices having light emitting surfaces of various shapes. This is a method for manufacturing a light-emitting device capable of forming a film.

  As described above, according to the phosphor coating apparatus according to the present invention, when the phosphor dispersion film is formed by the spray method, the phosphor mixture is applied by spraying upward, so that the mist floating in the air is natural. A phosphor capable of forming a phosphor dispersion film having a uniform film thickness with little unevenness in density, with only the phosphor mixture sprayed upwards without falling and adhering to the light emitting surface. A coating device can be obtained. For this reason, it is possible to reduce the unevenness of coating of the phosphor dispersion film and suppress the change in chromaticity. Further, since the spray nozzle is disposed upward, the phosphor is prevented from remaining at the tip of the nozzle, and the phosphor coating apparatus does not remain and solidify.

  Further, according to the method for manufacturing a light emitting device according to the present invention using this phosphor coating apparatus, it is possible to manufacture an LED having a phosphor dispersion film having a uniform film thickness with little density unevenness.

  The phosphor coating device and the light emitting device manufacturing method according to the present invention include a light emitting device (LED that emits third light of a desired color by mixing primary light emitted from an LED light emitting element and secondary light emitted from a phosphor. The phosphor coating device and the light emitting device can be suitably applied to a light source.

DESCRIPTION OF SYMBOLS 1 LED board 3 LED light emitting element 3a Light emission surface 6 Phosphor dispersion film (wavelength conversion part)
DESCRIPTION OF SYMBOLS 10 Phosphor coating apparatus 11 Tank 12 Agitation mechanism 13 Piping 14 Spray nozzle 15 LED support part 20 Phosphor mixed liquid LD Light emitting device (LED light source)

Claims (8)

A phosphor coating apparatus used for manufacturing a light emitting device having a light emitting element and a wavelength conversion unit including a phosphor that converts the wavelength of light emitted from the light emitting element,
The light emitting element is an LED light emitting element, and on the light emitting surface of the LED light emitting element mounted on the LED substrate, a phosphor mixed liquid in which a predetermined phosphor is dispersed is applied by spray means,
The light emitting surface of the LED light emitting element faces downward, a spray nozzle is disposed below the LED light emitting element, and the phosphor mixed liquid is sprayed upward from the spray nozzle, and the phosphor mixed liquid is applied to the light emitting surface. A phosphor coating apparatus characterized by coating a phosphor.   The phosphor coating device is stored in the LED support portion that supports the LED substrate with the light emitting surface of the LED light emitting element facing downward, the tank that stores the phosphor mixture, the spray nozzle, and the tank. The phosphor coating apparatus according to claim 1, further comprising a pipe for feeding the phosphor mixture liquid to the spray nozzle.   3. The phosphor coating apparatus according to claim 1, wherein a spray angle of the spray nozzle is upward in a vertical direction or upward in a diagonally upward range inclined by a predetermined angle from the vertical direction.   The said LED support part can displace the said LED board to the diagonal downward direction which inclined the said light emission surface in the perpendicular downward direction and this perpendicular downward direction by the predetermined angle, The Claim 2 or 3 characterized by the above-mentioned. Phosphor coating device.   The phosphor coating apparatus according to claim 3 or 4, wherein the predetermined angle is at most 75 degrees. A method of manufacturing a light emitting device having a light emitting element and a wavelength conversion unit including a phosphor that converts the wavelength of light emitted from the light emitting element,
The light emitting element is an LED light emitting element, and using a spray nozzle, a phosphor applying step of applying a phosphor mixed liquid in which a predetermined phosphor is dispersed on the light emitting surface of the LED light emitting element mounted on the LED substrate And a firing step of firing the applied phosphor mixed liquid to form a phosphor dispersion film and forming the wavelength conversion unit,
The method for manufacturing a light-emitting device, wherein the phosphor coating process is an upward coating process in which the phosphor mixed liquid is blown upward from the spray nozzle and the phosphor mixed liquid is coated on the light emitting surface.   The light emitting device manufacturing method according to claim 6, wherein the spray angle of the spray nozzle in the upward coating step is upward in the vertical direction or upward in a diagonally upward range inclined by a predetermined angle from the vertical direction. Method.   The method for manufacturing a light emitting device according to claim 7, wherein the predetermined angle is at most 75 degrees.

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