JP2012186319A - Light-emitting device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit occurrence of variation in chromaticity among light-emitting devices in the case of mass producing the light-emitting devices.SOLUTION: A manufacturing method of a light-emitting device including an LED element 3 radiating light of a predetermined first wavelength, and a wavelength conversion part containing phosphor particles radiating light of a second wavelength different from the first wavelength depending on irradiation of light of the first wavelength is disclosed. The manufacturing method comprises: (A) a first coating step of coating a phosphor coating liquid 40 containing the phosphor particles and an antisetting additive on the LED element 3; (B) a chromaticity measuring step of measuring chromaticity of light penetrating the phosphor coating liquid 40 coated on the LED element 3 by causing the LED element 3 to emit light; and (C) a second coating step of coating the phosphor coating liquid 40 on the LED element 3 again based on a measurement value of the chromaticity.

Description

  The present invention relates to a method for manufacturing a light emitting device, and more particularly to a technique suitable for mass production of a light emitting device.

Light-emitting elements using LED elements are used in various applications with increasing demands for higher luminance and energy saving of the elements, and the applications are further expanding.
In particular, in LED lighting (light emitting device) such as an electric lamp or a backlight of a liquid crystal display device that requires white light, an LED element that emits blue light and a phosphor that emits yellow light when excited by the blue light. A technique has been developed to obtain white light by mixing light with each other. In addition, as a light emitting device that obtains white light using an LED element and a phosphor, a white light is also obtained by combining an LED element that emits ultraviolet light and a phosphor that emits blue, green, and red light by ultraviolet light. A type that uses light and a type that uses white light by combining a LED element that emits blue light and a phosphor that emits red and green light have been studied.
A light emitting device that obtains white light using such a phosphor can obtain white light with one LED element, compared to a type that obtains white light by combining a plurality of LED elements having different colors. It can be simplified and power consumption can be suppressed, and is particularly preferably used.

However, when white light is obtained by combining the LED element and the phosphor, white light is obtained by the balance between the light emitted from the LED element and the light emitted from the phosphor. The color of the light emitting device is not white light due to being colored in a different color (color shift), and the color unevenness that the emitted light in white illumination differs in color (chromaticity) depending on the observation angle Improvements were needed due to problems.
Also, conventionally, a method of providing a phosphor layer around the LED element to form white LED lighting by applying and curing the LED particle on the LED element in a state where the phosphor particles are added and dispersed in the curable resin. In general, the phosphor particles are inorganic metal compounds having a very high specific gravity. Therefore, the phosphor particles are precipitated when cured in the curable resin, and the phosphor particles are deposited on the LED element. There has been a problem that color accumulation and color unevenness occur due to uneven deposition.

For such a problem, techniques such as Patent Documents 1 and 2 have been studied.
According to the technique of Patent Document 1, an attempt is made to prevent sedimentation of phosphor particles having a high specific gravity by containing a phosphor particle sedimentation preventing material in the liquid sealing material in order to reduce color unevenness of the light emitting device. (See paragraphs 0019-0025, etc.). Furthermore, according to the technique of Patent Document 1, a liquid sealing material is added to the periphery of the light emitting element, and the light emitting element is cured while being rotated, thereby reducing a chromaticity difference (that is, color unevenness) in the light emitting element. (See paragraph 0027 and FIG. 3).
According to Patent Document 2, phosphor particles are uniformly deposited on a light emitting surface (upper surface, side surfaces, and corner portions) of a light emitting element to increase wavelength conversion efficiency (see paragraphs 0032 to 0034, etc.). In particular, according to Patent Document 2, phosphor particles cannot be applied at the corners and side surfaces of the light emitting element, and wavelength conversion efficiency is reduced, and chromaticity deviation and color tone unevenness in each direction occur. On the other hand, these problems are attempted to be solved by spraying a coating liquid containing a phosphor while rotating in a mist-like and spiral manner (see paragraphs 0056 to 0058 and FIG. 4).

JP 2004-153109 A JP 2003-115614 A

According to the technique described above, it is considered that the color unevenness in the apparatus, that is, the chromaticity shift due to the angle of the light emitted from the light emitting device (white LED illumination) can be improved to some extent.
However, in recent years, a light-emitting device has been used for high-luminance automobile lighting and store lighting in which chromaticity is particularly important. "Apparatus" has been constructed, and it has become important to strictly match the chromaticity of each light-emitting device. That is, in a case where a single white illumination device is configured using a plurality of light emitting devices (LED elements) for high brightness, the color of the illumination device is far away when the chromaticity difference between the light emitting devices is far away. Since it appears as unevenness, it is necessary to suppress variation in chromaticity between light emitting devices as compared to the conventional art.

However, as described above, when a light emitting device is formed by spraying and applying a liquid material containing phosphor particles on a light emitting element with a spoo or the like, color unevenness in the light emitting device itself is adjusted by adjusting the injection conditions or by using an anti-settling material. However, when manufacturing a large number of light emitting devices continuously in large quantities, clogging due to changes in environmental temperature and humidity, changes in temperature due to the drive heat of the spray device, and hardening of the liquid adhering to the spray nozzle It is considered that chromaticity variation occurs between the light emitting devices due to various causes such as the above.
Therefore, a main object of the present invention is to provide a method for manufacturing a light emitting device capable of suppressing the occurrence of chromaticity variation among the light emitting devices when the light emitting devices are mass-produced.

In order to solve the above problems, according to one aspect of the present invention,
Wavelength conversion comprising: a light emitting element that emits light having a predetermined first wavelength; and phosphor particles that emit light having a second wavelength different from the first wavelength when irradiated with light having the first wavelength In a method for manufacturing a light emitting device having a portion,
A first coating step of coating a phosphor coating liquid containing the phosphor particles and an anti-settling agent on a light emitting element;
A chromaticity measuring step of causing the light emitting element to emit light and measuring the chromaticity of light transmitted through the phosphor coating liquid applied on the light emitting element;
Based on the measured value of chromaticity, a second coating step of coating the phosphor coating solution again on the light emitting element;
A method for manufacturing a light-emitting device is provided.

According to another aspect of the invention,
Wavelength conversion comprising: a light emitting element that emits light having a predetermined first wavelength; and phosphor particles that emit light having a second wavelength different from the first wavelength when irradiated with light having the first wavelength In a method for manufacturing a light emitting device having a portion,
A first coating step of coating a phosphor coating liquid containing the phosphor particles and an anti-settling agent on a transparent substrate and the light emitting element;
A chromaticity measuring step of irradiating the transparent substrate with light of the first wavelength and measuring chromaticity of the light transmitted through the transparent substrate and the phosphor coating liquid;
Based on the measured value of chromaticity, a second coating step of coating the phosphor coating solution again on the light emitting element;
A method for manufacturing a light-emitting device is provided.

According to the present invention, the chromaticity is measured in the chromaticity measurement step, and the phosphor coating liquid is applied again based on the measured value of the chromaticity, so that the chromaticity during the manufacturing of the light emitting device can be grasped. The excess and deficiency of the coating amount of the phosphor coating solution in the first coating step can be corrected by the processing in the second coating step.
As a result, even when the light emitting devices are produced in large quantities, it is possible to suppress the occurrence of individual color unevenness in each light emitting device, and in turn, to suppress the occurrence of chromaticity variation between the light emitting devices. Can do.

It is sectional drawing which shows schematic structure of a light-emitting device. It is a schematic diagram for demonstrating schematically the manufacturing apparatus and manufacturing method of the light-emitting device concerning 1st Embodiment. It is a schematic diagram for demonstrating schematically the manufacturing apparatus and manufacturing method of the light-emitting device concerning 2nd Embodiment.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
As shown in FIG. 1, the light emitting device 100 has a package 1 having a concave cross section. A metal part 2 (wiring) is provided in a recess (bottom part) of the package 1, and a rectangular parallelepiped LED element 3 is disposed on the metal part 2. The LED element 3 is an example of a light emitting element that emits light of a predetermined wavelength. A protruding electrode 4 is provided on the surface of the LED element 3 facing the metal part 2, and the metal part 2 and the LED element 3 are connected via the protruding electrode 4 (flip chip type).
Here, a configuration in which one LED element 3 is provided for one package 1 is illustrated, but a plurality of LED elements 3 may be provided in a recess of one package 1.

  In the present embodiment, a blue LED element is used as the LED 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.

  A wavelength converter 6 is formed in the recess of the package 1 so as to seal the periphery of the LED element 3. The wavelength conversion unit 6 is a part that converts light having a predetermined wavelength emitted from the LED element 3 into light having a wavelength different from this, and the predetermined wavelength from the LED element 3 is included in the translucent ceramic layer. Phosphor particles that are excited by the light and emit fluorescence with a wavelength different from the excitation wavelength.

  Next, the manufacturing apparatus (10) for the light emitting device 100 will be described.

As shown in FIG. 2, the manufacturing apparatus 10 has a belt conveyor type moving table 20 that can move back and forth. A spray device 30, an inspection device 50, and two spray devices 60 and 70 are disposed above the moving table 20 in the moving direction.
According to the manufacturing apparatus 10, a plurality of packages 1 in which the LED elements 3 are mounted in advance are transported with the movement of the moving table 20 in a state of being placed on the moving table 20, and the wavelength conversion unit 6 is manufactured during the transfer. Is done.

The spray device 30 has a configuration capable of ejecting a coating liquid.
Specifically, the spray device 30 has a nozzle 32 into which air is fed, and an air compressor (not shown) for feeding air is connected to the nozzle 32. The hole diameter at the tip of the nozzle 32 is 20 μm to 2 mm, preferably 0.1 to 0.3 mm. The nozzle 32 is movable up and down, left and right, and back and forth.
For example, Anest Iwata's spray gun W-101-142BPG is used as the nozzle 32, and Anest Iwata's OFP-071C is used as the compressor.
The angle of the nozzle 32 can also be adjusted, and the nozzle 32 can be tilted with respect to the movable table 20 (or the package 1 installed thereon). The angle of the nozzle 32 with respect to the discharge target (package 1 or LED element 3) can be adjusted in the range of 0 to 90 ° when the horizontal direction is 0 °.
A tank 36 is connected to the nozzle 32 via a connecting pipe 34. The tank 36 stores a phosphor coating solution 40 (see below) containing phosphor particles and an anti-settling agent. The tank 36 contains a stirring bar, and the phosphor coating liquid 40 is constantly stirred. If the phosphor coating liquid 40 is stirred, sedimentation of the phosphor having a large specific gravity can be suppressed, and the phosphor can be kept dispersed in the phosphor coating liquid 40.
For example, Anest Iwata PC-51 is used as the tank.

The inspection device 50 has a chromaticity measuring device 52.
The chromaticity measuring device 52 is a measuring device that measures the chromaticity of received light.
The two spray devices 60 and 70 basically have the same configuration as the spray device 30. However, in the spray device 70, the ceramic precursor coating liquid 42 containing the ceramic precursor is stored in the tank 36.
The spray device 30, the inspection device 50 (chromaticity measuring device 52), and the spray device 60 are connected to a control device 80. In particular, according to the manufacturing apparatus 10, the chromaticity measurement value (measurement result) of the chromaticity measuring device 52 is transmitted to the control device 80, and the control device 80 controls the spray device 60 based on the measurement result to perform the spray device. 60 operations are controlled.

  Then, the manufacturing method of the light-emitting device 100 is demonstrated.

When manufacturing the light-emitting device 100, the manufacturing apparatus 10 is used.
Specifically, according to the method for manufacturing the light emitting device 100, the plurality of packages 1 on which the LED elements 3 are mounted in advance are placed on the moving table 20, and are sequentially transported at a constant speed. Processes (D) to (D) are executed.
(A) The phosphor coating liquid 40 is applied onto the LED element 3 using the spray device 30 (B) The phosphor coating liquid applied on the LED element 3 using the inspection device 50 by causing the LED element 3 to emit light. Measure the chromaticity of the light transmitted through 40 (C) Apply the phosphor coating liquid 40 again on the LED element 3 using the spray device 60 based on the measured value of chromaticity (D) Use the spray device 70 Then, the ceramic precursor coating liquid 42 is applied onto the LED element 3 on which the phosphor coating liquid 40 is applied, and the phosphor coating liquid 40 and the ceramic precursor coating liquid 42 applied on the LED element 3 are heated. Harden

  First, the phosphor used in the step (A), the anti-settling agent (swellable particles or inorganic particles), the phosphor coating liquid 40, the processing content, etc. will be described, and then the processing content in the step (B) ( The processing content of the process of C) will be described, and finally the ceramic precursor coating liquid (ceramic precursor) used in the process of (D) and the processing content will be described.

(A-1) Phosphor particles The phosphor is excited by the wavelength (excitation wavelength) of the emitted light from the LED 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.
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.

(A-2) Anti-settling agent As a method for preventing the settling of phosphor particles (a method for adjusting the viscosity of the phosphor coating solution 40), a method of adding swellable particles or inorganic particles to a solvent can be mentioned. Any method can be used as long as the body coating solution 40 can be thickened, and the method is not limited to this.

(A-2.1) Swellable particles Examples of the swellable particles include layered silicate minerals.
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 by adding water to the mixed solution, a card house structure in which water enters and swells between layers of the smectite structure has an effect of greatly increasing the viscosity of the mixed solution.
When the content of the layered silicate mineral in the ceramic layer is less than 1% 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 1% by weight to 20% by weight, and more preferably 1% by weight to 10% by weight.
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.

(A-2.2) Inorganic particles The inorganic particles (oxide fine particles) fill not only the thickening effect that increases the viscosity of the phosphor coating liquid 40 but also the gap generated at the interface between the organometallic compound and the phosphor. It also has a filling effect and a film strengthening effect that improves the film strength of the ceramic layer after heating.
Examples of the inorganic particles used in the present invention include oxide fine particles such as silicon oxide, titanium oxide and zinc oxide, fluoride fine particles such as magnesium fluoride, and the like. 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 particles in the ceramic layer is less than 1% by weight, the above-described effects cannot be sufficiently obtained. On the other hand, when the content of the inorganic particles exceeds 20% by weight, the strength of the ceramic layer after heating is lowered. Therefore, the content of the inorganic particles in the ceramic layer is preferably 1% by weight or more and 20% by weight or less, and more preferably 1% by weight or more and 10% by weight or less. The average particle diameter of the inorganic 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 particles can be measured, for example, by a Coulter counter method.

(A-3) Preparation of phosphor coating liquid 40 As a procedure for preparing phosphor coating liquid 40, first, swellable particles or inorganic particles are premixed in an organic solvent, and then phosphor and / or water are mixed. . Alternatively, first, swellable particles or inorganic particles, a phosphor and water may be premixed, and then an organic solvent may be mixed. Thereby, swellable particle | grains or inorganic particle | grains can be mixed uniformly, and the thickening effect can be heightened more.
The viscosity of the phosphor coating liquid 40 is 10 to 500 cP, preferably 12 to 500 cP, more preferably 20 to 400 cP, and most preferably 50 to 300 cP. These viscosities were measured using a vibration viscometer (VM-10A-L manufactured by CBC).
Note that the phosphor coating liquid 40 may contain only swellable particles, may contain only inorganic particles, or may contain both swellable particles and inorganic particles.

(A-4) Processing contents The spray device 30 is set at a predetermined position, air is sent to the nozzle 32, and the phosphor coating solution 40 is directed from the tip of the nozzle 32 toward the LED element 3 of the package 1 being conveyed. Spray and apply.
Thereafter, while the package 1 is being transferred, the phosphor coating liquid 40 is dried at a temperature from room temperature to about 50 ° C.

(B) Processing content When the package 1 passes through the inspection device 50, the LED element 3 emits light, and the light transmitted through the phosphor coating liquid 40 is received by the chromaticity measuring device 52, and the chromaticity of the light is measured. taking measurement.
The measurement result (measured value of chromaticity) is transmitted to the control device 80.

(C) Processing content As in the step (A), the spray device 60 is used to spray and apply the phosphor coating solution 40 from the tip of the nozzle 32 toward the LED element 3 of the package 1 being conveyed. .
Thereafter, as in the step (A), the phosphor coating liquid 40 is dried at a temperature from room temperature to about 50 ° C. while the package 1 is being transferred.

In the control device 80, the coating amount of the phosphor coating solution 40 corresponding to the final film thickness of the phosphor coating solution 40 after the end of the step (C) is set as a “final set value”, and (A The application amount of the phosphor coating liquid 40 in the step (1) is set as the “first set value”.
The first set value is a fixed value smaller than the final set value.
In step (A), based on the first set value, the spray device 30 is controlled to adjust the spray pressure, spray temperature (temperature of the nozzle 32) of the phosphor coating liquid 40, and the like.
On the other hand, in the step (C), the application amount of the phosphor coating liquid 40 to be applied in the step (C) is calculated as the “second design value” based on the measurement result of the chromaticity measuring device 52. Is set in the control device 80, and based on the second set value, the spray device 60 is controlled to adjust the spray pressure, spray temperature (temperature of the nozzle 32) of the phosphor coating liquid 40, and the like.
The second set value is a value obtained by subtracting the first set value from the final set value, and is a variation value that takes into account the excess or deficiency of the coating amount of the phosphor coating liquid 40 in the step (A).

For example, when the final set value is set so that the final film thickness of the phosphor coating solution 40 after the completion of the step (C) is 40 μm, in the step (A), the phosphor coating solution A coating amount of 40 (after drying) with a film thickness of 25 μm is set as the first design value. Actually, the phosphor coating liquid 40 with a thickness of 23 μm is applied from the measured value of chromaticity. Assuming that
At this time, since the phosphor coating liquid 40 in a film thickness of 2 μm is insufficient at the time after the completion of the process (A), the phosphor coating liquid 40 (after drying) is insufficient in the process (C). The coating amount that increases the film thickness by 2 μm is calculated and set as the second design value.
On the other hand, when the phosphor coating liquid 40 in an amount of 2 μm in terms of film thickness is excessive after the completion of the process (A), in the process (C), the phosphor coating liquid 40 ( The coating amount that reduces the film thickness by 2 μm (after drying) is calculated and set as the second design value.

As shown in FIG. 2, in the process (A) and the process (C), a mask member 90 is disposed between the nozzle 32 of the spray device 30 and the package 1 before applying the phosphor coating liquid 40. Then, the application region of the phosphor coating solution 40 may be controlled, and the mask member 90 may be collected after the phosphor coating solution 40 is applied.
The mask member 90 may be used in any of the steps (A) and (C), but is preferably used in both steps from the viewpoint of the recovery rate of the phosphor particles. If the mask member 90 is recovered, expensive phosphor particles can be recovered and reused.
When the recovery of the mask member 90 is performed after the step (D), the ceramic precursor coating liquid 42 adheres to the mask member 90 and it becomes difficult to recover the phosphor particles, but the recovery of the mask member 90 is performed (D If the process is performed before the step (), the phosphor particles can be easily recovered from the mask member 90. That is, the phosphor particles can be recovered by a simple operation of dissolving or incinerating the recovered mask member 90.

(D-1) Ceramic precursor coating solution 42
The ceramic precursor coating liquid 42 is a solution in which a metal compound as a ceramic precursor is dispersed in a solvent, and the type of metal is not limited as long as a translucent ceramic can be formed.

(D-1.1) Sol-gel solution The ceramic precursor coating solution 42 is a solution in which a ceramic is formed by heating the gel after gelation by a reaction such as hydrolysis (sol-gel solution). Alternatively, the ceramic may be directly formed without gelation by volatilizing the solvent component.
In the former case (sol-gel solution), the metal compound may be an organic compound or an inorganic compound. Examples of preferable metal compounds include metal alkoxides, metal acetylacetonates, metal carboxylates, nitrates, and oxides. Of these, metal alkoxides are preferred because they are easily gelled by hydrolysis and polymerization reaction, and tetraethoxysilane is particularly preferred. A plurality of types of metal compounds may be used in combination.
The ceramic precursor coating liquid 42 preferably contains water, a solvent, a catalyst, and the like for hydrolysis in addition to the metal compound.
Examples of the solvent include alcohols such as methanol, ethanol, propanol, and butanol.
Examples of the catalyst include hydrochloric acid, sulfuric acid, nitric acid, acetic acid, hydrofluoric acid, ammonia and the like.
When tetraethoxysilane is used as the metal compound, it is preferable to use 138 parts by mass of ethyl alcohol and 52 parts by mass of pure water with respect to 100 parts by mass of tetraethoxysilane. In this case, the heating temperature for heating the gel is preferably 120 to 500 ° C., and more preferably 120 to 150 ° C. from the viewpoint of further suppressing deterioration of the LED element 4 and the like. Moreover, also when using polysiloxane as a metal compound, 120-500 degreeC is preferable for the heating temperature after application | coating, and it is more preferable to set it as 120-150 degreeC from a viewpoint which suppresses deterioration of LED element 4 grade | etc., More.

(D-1.2) Polysilazane Polysilazane can also be used as a ceramic precursor.
The polysilazane used in the present invention is represented by the following general formula (i).
(R ¹ R ² SiNR ³ ) _n (i)
In formula (i), R1, R2, and R3 each independently represent a hydrogen atom, an alkyl group, an aryl group, a vinyl group, or a cycloalkyl group, and at least one of R1, R2, and R3 is a hydrogen atom. , Preferably all are hydrogen atoms, n represents an integer of 1-60.
The molecular shape of polysilazane may be any shape, for example, linear or cyclic.
Polysilazane represented by the above formula (i) and a reaction accelerator as required are dissolved in an appropriate solvent and cured by heating, excimer light treatment, UV light treatment, and excellent heat resistance and light resistance. A ceramic film can be made. In particular, the effect of preventing penetration of moisture can be further improved by heat curing after irradiating and curing UVU radiation (eg, excimer light) containing a wavelength component in the range of 170 to 230 nm.
As the reaction accelerator, an acid, a base, or the like is preferably used, but it may not be used. Examples of reaction accelerators include triethylamine, diethylamine, N, N-diethylethanolamine, N, N-dimethylethanolamine, triethanolamine, triethylamine, hydrochloric acid, oxalic acid, fumaric acid, sulfonic acid, acetic acid, nickel, iron, palladium , Metal carboxylates including iridium, platinum, titanium, and aluminum, but are not limited thereto.
Particularly preferred when using a reaction accelerator is a metal carboxylate, and the addition amount is preferably 0.01 to 5 mol% based on polysilazane.
As the solvent, aliphatic hydrocarbons, aromatic hydrocarbons, halogen hydrocarbons, ethers, and esters can be used. Preferred are methyl ethyl ketone, tetrahydrofuran, benzene, toluene, xylene, dimethyl fluoride, chloroform, carbon tetrachloride, ethyl ether, isopropyl ether, dibutyl ether, and ethyl butyl ether.
The polysilazane concentration is preferably higher, but since the increase in concentration leads to a shortening of the polysilazane storage period, the polysilazane is preferably dissolved in the solvent at 5% by mass or more and 50% by mass or less.
Furthermore, when polysilazane is used as the ceramic precursor, the heating temperature after coating is preferably 120 to 500 ° C, and more preferably 120 to 150 ° C from the viewpoint of further suppressing deterioration of the LED element 4 and the like.

(D-2) Processing contents The LED of the package 1 that is transporting the ceramic precursor coating liquid 42 from the tip of the nozzle 32 using the spray device 70 in the same manner as in the steps (A) and (C). Spraying and coating toward the element 3.
Thereafter, the package 1 is transferred to a heating tank (not shown), and the phosphor coating solution 40 and the ceramic precursor coating solution 42 applied on the LED element 3 are heated (baked) at a temperature around 150 ° C. to be cured. Then, the wavelength converter 6 is formed (completed).
As a result, a large number of light emitting devices 100 can be manufactured sequentially.
The process in the step (D) is performed after the phosphor coating liquid 40 is applied in the step (A) (after the step (A) or after the step (B) and after the step (C). Before).

According to the above embodiment, the LED element 3 is actually caused to emit light in the step (B), and the phosphor coating solution 40 is applied again in the step (C) based on the chromaticity information. In the process of manufacturing (forming the wavelength conversion unit 6), the chromaticity during the manufacturing of the light emitting device 100 can be grasped, and the excess or deficiency of the actual chromaticity can be corrected in the process (C). .
As a result, even when the light emitting devices 100 are produced in large quantities, it is possible to suppress the occurrence of individual color unevenness in each light emitting device 100, and thus to suppress chromaticity variation among the light emitting devices 100. Can do.

Furthermore, when forming the wavelength conversion unit 6, the phosphor coating solution 40 and the ceramic precursor coating solution 42 are separately applied in the steps (A) and (C) and the step (D). The uneven application due to the body coating liquid 40 being cured at the time of application can be eliminated, and the uneven color of the light emitting device 100 can be reduced.
That is, when the coating liquid is applied in a state where the phosphor particles and the ceramic precursor are mixed and firing and curing are performed, the firing temperature is as high as around 150 ° C., so the solvent contained in the coating liquid is Volatilization occurs rapidly, and cracks and bubbles are generated in the wavelength conversion unit 6 or the phosphor particles in the wavelength conversion unit 6 are unevenly distributed, resulting in color unevenness. On the other hand, if the phosphor coating liquid 40 not containing a ceramic precursor is first applied in the steps (A) and (C) and dried at a temperature from room temperature to about 50 ° C., the phosphor particles are packaged to some extent. (The uneven distribution of the phosphor particles can be eliminated), and the solvent is applied from the upper layer of the phosphor coating solution 40 even if the ceramic precursor is applied from the top in the step (D). Since only volatilizes, it is possible to prevent the generation of bubbles and cracks even at high temperatures, and to suppress the occurrence of uneven color.

Note that the phosphor coating liquid 40 and the ceramic precursor coating liquid 42 may be applied (dropped or discharged) using a dispenser or an ink jet instead of the spray coating devices 30, 60, and 70.
In the case of using a dispenser, a nozzle that can control the dropping amount of the coating solution and does not cause clogging of nozzles such as phosphor particles is used. For example, a non-contact jet dispenser manufactured by Musashi Engineering Co., Ltd. or its dispenser can be used.
Also in the case of using an ink jet, a nozzle that can control the discharge amount of the coating liquid and does not cause nozzle clogging of the phosphor particles is used. For example, an ink jet apparatus manufactured by Konica Minolta IJ can be used.

[Second Embodiment]
The second embodiment is different from the first embodiment mainly in the following points, and is otherwise the same as the first embodiment.

As shown in FIG. 3, the inspection device 50 is provided with an LED element 54.
The LED element 54 is an element that emits light similar to that of the LED element 3.
The LED element 54 is disposed below the movable table 20 and is disposed at a position facing the light receiving unit of the chromaticity measuring device 52.

When the light emitting device 100 is manufactured, the transparent substrate 92 is also placed on the moving table 20 and transported in addition to the package 1 in which the LED elements 3 are mounted in advance.
The transparent substrate 92 is periodically arranged every time a predetermined number of packages 1 are conveyed.
As the transparent substrate 92, for example, a glass plate can be used.
An opening 22 for transmitting light is formed at a position where the transparent substrate 92 of the moving base 20 is disposed.

In the step (A), the phosphor coating liquid 40 is sprayed / coated on the transparent substrate 92 as well as the LED element 3 of the package 1 and dried.
In the step (B), when the transparent substrate 92 passes through the inspection apparatus 50, the LED element 54 is caused to emit light, and the transparent substrate 92 is irradiated with the same light as the LED element 3 through the opening 22 of the moving table 20. Then, the light transmitted through the transparent substrate 92 and the applied phosphor coating solution 40 is received by the chromaticity measuring device 52 and the chromaticity of the light is measured.
In the step (C), the application amount of the phosphor coating liquid 40 to be applied is calculated and set as the second set value based on the measured chromaticity value obtained from the transparent substrate 92, For the package 1, the spray device 60 is controlled based on the second set value to adjust the spray pressure, spray temperature (temperature of the nozzle 32), etc. of the phosphor coating liquid 40.

  According to the above embodiment, the LED element 54 of the inspection apparatus 50 is caused to emit light and the chromaticity is measured with the transparent substrate 92 as a measurement target, so that the LED element 3 cannot emit light during the manufacturing of the light emitting apparatus 100. Even in such a case, the chromaticity during the manufacturing of the light emitting device 100 can be grasped, and variations in chromaticity among the light emitting devices 100 can be suppressed.

(1) Preparation of sample (1.1) Comparative example 1
11 g of non-surface-treated hydrophilic smectite (Lucentite SWN, manufactured by Co-op Chemical) and 220 g of pure water were mixed and dispersed, and then 100 g of phosphor was mixed to prepare a phosphor coating solution.
While sequentially carrying 1000 blue LED elements (the size of the light emitting part is vertical x horizontal = 1 mm x 1 mm) by a belt conveyor, the phosphor layer after drying has a film thickness of 35 μm. In this manner, the LED elements were sequentially coated with a spray coating apparatus and dried at 50 ° C. for 10 minutes.
Further, a polysiloxane dispersion (polysiloxane 14% by weight, isopropyl alcohol 86% by weight) is applied so that the film thickness after firing is 1 μm by a spray coating device from above the LED element coated with the phosphor coating liquid. It was applied and baked at 150 ° C. for 1 hour to obtain 1000 light emitting devices.
Nine pieces were randomly selected from the obtained 1,000 light emitting devices, and nine pieces were arranged at intervals of 5 mm × 5 mm to obtain a white illumination device.

(1.2) Example 1
Two coating portions of the phosphor coating solution were provided, and a chromaticity measuring device was provided between them.
A phosphor coating solution was applied onto the blue LED element, dried and passed through a chromaticity measuring device. At that time, the LED element was caused to emit light, and the chromaticity was measured.
At this time, the wavelength conversion portion had a thickness of 25 μm.
Thereafter, a small amount of a phosphor coating solution was applied at the second application unit in accordance with the measured chromaticity and dried.
The thickness of the wavelength conversion part after drying was 40 μm.
Further, a polysiloxane dispersion (polysiloxane 14% by weight, isopropyl alcohol 86% by weight) is applied from above the wavelength conversion part by a spray coating device so that the film thickness after baking becomes 1 μm. After baking for a time, 1000 light emitting devices were obtained.
Nine pieces were randomly selected from the obtained 1,000 light emitting devices, and nine pieces were arranged at intervals of 5 mm × 5 mm to obtain a white illumination device.

(1.3) Example 2
Two application portions of the phosphor coating solution were provided, and a chromaticity meter was provided between them.
Further, a transparent substrate was provided between the LED elements, and an opening for transmitting light was provided at a place where the transparent substrate of the belt conveyor was disposed.
A phosphor coating solution is applied onto the LED element and the transparent substrate, and after drying, the transparent substrate is first passed through a chromaticity measuring device. At that time, blue LED light is irradiated from the bottom of the belt conveyor, and the resulting light is colored. The chromaticity information was obtained by measuring with a color measuring instrument.
The thickness of the wavelength conversion part at this time was 20 micrometers.
Then, based on the obtained chromaticity information, in the 2nd application part, the fluorescent substance coating liquid was apply | coated in trace amount according to the measured chromaticity, and it dried.
The thickness of the wavelength conversion part after drying was 39 μm.
Furthermore, a polysiloxane dispersion (polysiloxane 14% by weight, isopropyl alcohol 86% by weight) is applied from above the wavelength conversion unit by a spray coating device so that the film thickness after baking becomes 1 μm, and is 150 ° C. for 1 hour. Firing was performed to obtain 1000 light emitting devices.
Nine pieces were randomly selected from the obtained 1,000 light emitting devices, and nine pieces were arranged at intervals of 5 mm × 5 mm to obtain a white illumination device.

(2) Evaluation of color unevenness of samples The chromaticity distribution of white illumination of each sample was examined.
Specifically, since the irradiation light can be evaluated two-dimensionally by using a two-dimensional color luminance meter, the irradiation light of the white illumination of each sample using the two-dimensional color luminance meter CA2000 manufactured by Konica Minolta Sensing Co., Ltd. (Chromaticity x value, y value) was measured. The chromaticity difference between the chromaticity x value and y value in the obtained irradiation light was calculated. The calculation results are shown in Table 1.
For example, if there is color unevenness in the irradiation light, a yellow portion and a blue portion exist, and the chromaticity difference between the portions becomes large.

As shown in Table 1, the sample of Comparative Example 1 has a large chromaticity difference, and it is considered that color unevenness occurs in the irradiation light. On the other hand, in the samples of Examples 1 and 2, it can be seen that the chromaticity difference is low and no color unevenness occurs (the occurrence of color unevenness is remarkably suppressed).
From the above, in order to suppress the occurrence of chromaticity variation between the light emitting devices (to suppress the occurrence of color unevenness), the chromaticity is measured during the manufacturing process of the light emitting device, and the phosphor is based on the measured value. It can be seen that it is useful to control the coating amount of the coating solution.

1 Package 2 Metal Part 3 LED Element 4 Projection Electrode (Bump)
6 Wavelength conversion unit 10 Manufacturing device 20 Moving table 22 Opening portion 30 Spray device 32 Nozzle 34 Connection pipe 36 Tank 40 Phosphor coating solution 42 Ceramic precursor coating solution 50 Inspection device 52 Chromaticity measuring device 54 LED element 60, 70 Spray device 80 control device 90 mask member 92 transparent substrate 100 light emitting device

Claims (13)

Wavelength conversion comprising: a light emitting element that emits light having a predetermined first wavelength; and phosphor particles that emit light having a second wavelength different from the first wavelength when irradiated with light having the first wavelength In a method for manufacturing a light emitting device having a portion,
A first coating step of coating a phosphor coating liquid containing the phosphor particles and an anti-settling agent on a light emitting element;
A chromaticity measuring step of causing the light emitting element to emit light and measuring the chromaticity of light transmitted through the phosphor coating liquid applied on the light emitting element;
Based on the measured value of chromaticity, a second coating step of coating the phosphor coating solution again on the light emitting element;
A method for manufacturing a light-emitting device. Wavelength conversion comprising: a light emitting element that emits light having a predetermined first wavelength; and phosphor particles that emit light having a second wavelength different from the first wavelength when irradiated with light having the first wavelength In a method for manufacturing a light emitting device having a portion,
A first coating step of coating a phosphor coating liquid containing the phosphor particles and an anti-settling agent on a transparent substrate and the light emitting element;
A chromaticity measuring step of irradiating the transparent substrate with light of the first wavelength and measuring chromaticity of the light transmitted through the transparent substrate and the phosphor coating liquid;
Based on the measured value of chromaticity, a second coating step of coating the phosphor coating solution again on the light emitting element;
A method for manufacturing a light-emitting device. In the manufacturing method of the light-emitting device of Claim 1 or 2,
The method for producing a light-emitting device, wherein the precipitation inhibitor is a layered silicate mineral. In the manufacturing method of the light-emitting device according to claim 3,
The method for manufacturing a light-emitting device, wherein the layered silicate mineral is a swellable viscosity mineral. In the manufacturing method of the light-emitting device according to claim 4,
The method for producing a light-emitting device, wherein the swellable viscosity mineral has a smectite structure. In the manufacturing method of the light-emitting device of Claim 1 or 2,
In the first application step and the second application step,
A method of manufacturing a light emitting device, wherein the phosphor coating solution is applied using a spray coating device. In the manufacturing method of the light-emitting device of Claim 1 or 2,
In the first application step and the second application step,
A method of manufacturing a light emitting device, wherein the phosphor coating liquid is applied using a dispenser. In the manufacturing method of the light-emitting device of Claim 1 or 2,
In the first application step and the second application step,
A method for manufacturing a light emitting device, wherein the phosphor coating liquid is applied using an inkjet. In the manufacturing method of the light-emitting device as described in any one of Claims 1-8,
In at least one of the first application step and the second application step,
A method for manufacturing a light emitting device, comprising: arranging a mask member on the light emitting element before applying the phosphor coating liquid; and collecting the mask member after applying the phosphor coating liquid. In the manufacturing method of the light-emitting device as described in any one of Claims 1-9,
After the first application step,
A ceramic precursor coating liquid containing a ceramic precursor is coated on the light emitting element coated with the phosphor coating liquid, and the phosphor coating liquid and the ceramic precursor coating liquid coated on the light emitting element. The manufacturing method of the light-emitting device characterized by providing the process of heating and hardening. In the manufacturing method of the light-emitting device as described in any one of Claims 1-10,
After the second application step,
A ceramic precursor coating liquid containing a ceramic precursor is coated on the light emitting element coated with the phosphor coating liquid, and the phosphor coating liquid and the ceramic precursor coating liquid coated on the light emitting element. The manufacturing method of the light-emitting device characterized by providing the process of heating and hardening. In the manufacturing method of the light-emitting device of Claim 10 or 11,
A method of manufacturing a light emitting device, wherein the ceramic precursor is polysiloxane. In the manufacturing method of the light-emitting device of Claim 10 or 11,
The method for manufacturing a light emitting device, wherein the ceramic precursor is polysilazane.

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