CN102618287B

CN102618287B - Method for preparing yellowgreen fluorescent powder for light-emitting diodes (LEDs)

Info

Publication number: CN102618287B
Application number: CN 201210075093
Authority: CN
Inventors: 周卫新; 顾竞涛; 李依群; 谢玉明
Original assignee: INTEMATIX PHOTOVOLTAIC (SUZHOU) Co Ltd
Current assignee: INTEMATIX PHOTOVOLTAIC (SUZHOU) Co Ltd
Priority date: 2012-03-20
Filing date: 2012-03-20
Publication date: 2013-10-30
Anticipated expiration: 2032-03-20
Also published as: CN102618287A

Abstract

The invention relates to a method for preparing yellowgreen fluorescent powder for light-emitting diodes (LEDs), and belongs to the field of preparation of luminescent materials. The method comprises the following steps of: batching, mixing, sintering, crushing, cleaning, drying, sieving and packaging. The method is characterized in that preprocessing step is added before the batching operation, and comprises the following steps of: sieving a matrix material, dehumidifying an activating agent and complexing a fluxing agent to form a composite fluxing agent; according to the mixing step, the dehumidified activating agent and the composite fluxing agent are put into a three-dimensional motion mixer to be mixed, and a premix and the sieved matrix material are introduced into the mixer to be mixed; according to the crushing step, sintered materials are screened by a vibrating screen and an ultrasonic wave classifying screen respectively and are introduced into an air flow crusher to be crushed; according to the cleaning step, powder to be cleaned is cleaned and classified; according to the sieving step, the powder obtained in the drying step is subjected to the particle size classification of finished products; and the powder which is subjected to the particle size classification is packaged to form the yellowgreen fluorescent powder for the LEDs. The method has the advantage that the yellowgreen fluorescent powder has the very ideal primary characteristic and secondary characteristic.

Description

The LED preparation method of yellow-green fluorescence powder

Technical field

The invention belongs to the luminescent material preparing technical field, be specifically related to the preparation method that a kind of LED uses the yellow-green fluorescence powder.

Background technology

Because white light LEDs has energy-saving and environmental protection, long service life, operating voltage is low and fast response time and basically can satisfy the human characteristics such as all requirements to artificial light, thereby be widely used in indoor particularly outdoor (also claim outdoor) illumination, the backlight of screen etc. is shown in outdoor lighting such as Landscape Lighting, stop-light, auto lamp, advertisement and demonstration, be after luminescent lamp and HID lamp the 4th generation light source.

At present, realize that the method for white light LEDs mainly contains following three kinds: the one, apply yellow fluorescent powder (mainly containing YAG:Ce) in blue chip, be mixed into white light by means of blue light and fluorescence; The 2nd, the encapsulation of the chip portfolio of three kinds of colors of red, green and blue, the luminous white light that directly is mixed into of chip; The 3rd, excite the fluorescent material of three kinds of colors of red, green, blue to be mixed into white light by means of the near-ultraviolet light chip.In these three kinds of methods, because the circuit relative complex of rear two kinds of methods and/or lack suitable fluorescent material or chip, thereby be difficult to be widely used, and first method is because circuit structure is simple and cost is comparatively cheap, thus in present White-light LED illumination dominate.

In published China and foreign countries patent documentation, be no lack of with the preparation method's of yellow fluorescent powder technical intelligence about LED and be seen in, be not limited to such as CN1482208A, CN101126024A (high temperature solid-state method); CN1664063A, CN101249978A (sol-gel method); CN101113333A, CN101012376A (precipitator method); CN1398817A (combustion method); CN1052745C (microwave method); CN1775904A, CN1597841A (vapor phase process); US6614179B1 (high temperature solid-state method).

And then, " a kind of preparation method of Yellow fluorescent powder used by white light LED " that " a kind of white light LEDs is with yellow fluorescent material and be total to the preparation method " that " preparation method of yellow fluorescent powder " that " synthetic method of phosphor for white light LED " that representative open source literature such as publication No. CN101760196 recommend, " yellow fluorescent powder and preparation method thereof " that CN101914381A provides, CN101948693A introduce, CN101962547A disclose and CN102234511A disclose, etc.

" a kind of based on blue-light excited phosphor for white light LED and preparation method thereof " of " compound, the containing fluorescent powder composition that comprises it and the light-emitting device " that " a kind of phosphor material powder and preparation method thereof and white light LED electric light source ", the CN1919854A that " a kind of yellow-green fluorescence powder material and the preparation method " that LED announces with the preparation method's of yellow-green fluorescence powder typical Introduction of Literatures such as Chinese patent application publication No. CN102352242A, publication number CN1927996A introduce provides and CN101824321A announcement, etc.

No matter be the LED yellow fluorescent powder, or LED yellow-green fluorescence powder, preparation method each other is basic identical, the step that namely comprises is followed successively by; Batching, batch mixing, burn till (sintering), broken (custom be called pulverize or ball milling), clean, dry and sieve, obtain LED with yellow or yellow-green fluorescence powder.

As is known in the industry, the up-conversion of ruddiness-visible light can be divided three classes according to the composition of matrix; One is halogen contained compound; Two is sulfide and oxide compound; Three are activator (being mainly rare earth element).Phonon energy is depended in the selection of matrix, generally, the phonon energy of matrix is larger, it is just stronger that radiationless relaxation (also claiming to move to jump) occurs rare earth ion, upper turnover ratio is just lower, and the material of therefore selecting to have lower phonon cut-off energy when the preparation luminescent material just can obtain higher up-conversion luminescence efficient (specifically can referring to " China rare earth journal " the 21st volume the 2nd phase P123-126).

The substrate material of fluorescent material mainly contains with Al ₂O ₃Aluminate fluorescent powder for representative; With B ₂O ₃Borate fluorescent powder for representative; And with SiO ₂Be the silicate fluorescent powder of representative, however the most frequently used be with Al ₂O ₃Aluminate fluorescent powder for representative.

There is the logical fraud of following two aspects in LED in the prior art with the preparation method of yellow-green fluorescence powder: one, because the substrate material (Al to being obtained by commercially available channel ₂O ₃, Lu ₂O ₃And Ga ₂O ₃), activator (CeO ₂) and fusing assistant H ₃BO ₃Lack the pre-process measure, thereby be difficult to select that to prepare required fluorescent material, luminous intensity and luminescent properties with the particle diameter specification that relatively approaches poor.Because that LED buys from commercially available channel with the production firm of yellow-green fluorescence powder and by the Al as one of main matrix material shown in Figure 1 ₂O ₃Only roughly satisfy D ₅₀Require (to annotate: D ₅₀Also be meso-position radius or median particle diameter, and D ₅₀In order to represent the mean particle size of powder), more particularly, because Al ₂O ₃Existing particle diameter is the aluminum oxide about 5.2 μ m in the substrate material, it is the aluminum oxide of 1-3 μ m that particle diameter is arranged again, also having particle diameter is the aluminum oxide of 9-15 μ m, therefore particle size distribution range is wider, thereby the particle diameter specification that is difficult to select with relatively approaching prepares required fluorescent material, finally causes occurring in high temperature solid state reaction the large phenomenon of globule size difference of lattice.Again because in view of rare-earth activated agent material such as CeO ₂Add-on in whole prescription is with respect to substrate material (Al ₂O ₃, Lu ₂O ₃And Ga ₂O ₃) less, add the rare earth material moisture absorption of making moist easily, often water ratio is ignored, namely do not dehumidified, so having not at the high temperature solid state reaction process middle-weight rare earths quantity of material of making fluorescent material, foot phenomenon occurs, cause reacting the product lattice defectiveness of generation, thereby the luminous intensity of fluorescent material is produced certain influence.Also because since fusing assistant in ion diffusion and form in the whole process of the luminous host with perfect lattice and play an important role, not only the crystal grain distribution of fluorescent material, luminous efficiency etc. are exerted an influence, and the hardness of agglomerate exerted an influence, if hardness is excessive, then in subsequent disposal, can destroy crystal morphology, affect the generation performance of fluorescent material; Its two because the substrate material (Al that in the batch mixing step, usually will take by weighing by weight ₂O ₃, Lu ₂O ₃And Ga ₂O ₃) activator (CeO ₂) and fusing assistant (H ₃BO ₃) put into rotary container and mix or put into stir shaft type stirred vessel and mix, and this each stirred vessel can only be made circumferential motion, therefore can only obtain relatively uniformly degree by prolonging mixing time (being generally about 40 hours).Yet, owing to mix for a long time, again because various raw materials are the dry type powder, therefore under moving for a long time, the mutual friction of powder phase and heating, viscosity is increased, and in friction process, produce static, cause agglomeration, the compound that this mixing method obtains is by shown in Figure 2, this Fig. 2 is scanning electron microscope (SEM) figure, as can be seen from Figure 2, even if through reaching mixing about 40 hours, but mixed effect still is unsatisfactory, and the mixed effect shortcoming account in can causing filling a prescription the less active material of share and flux material can not be dispersed in uniformly substrate material around, it is larger to show as the more grain growing of substrate material flux material distribution on every side in the high temperature solid state reaction process, otherwise side is little, and the active material more lattice growth that distributes is complete around the substrate material, otherwise the side lattice imperfection is serious.Because these drawbacks, the yellow fluorescence powder particle size distribution by shown in Figure 3 that obtains comparatively is short of, the lattice pattern is inconsistent, finally causes all relatively poor (primary characteristics: absorption spectrum, excitation spectrum, emmission spectrum, quantum yield and luminous efficiency etc. of the primary characteristic of fluorescent material and quadratic behavior; Quadratic behavior: dispersiveness, stability and light decay characteristic); They are three years old, by shown in Figure 4, owing to usually ball milling is adopted in the pulverizing of the powder (custom claims to burn till powder) that burns till, therefore in powder and ball-milling medium such as agate ball, glass sphere and/or corundum ball friction process, although macrobead is able to fragmentation, the powder of small particle size is also ground carefullyyer thereupon, so according to the known reason of industry, almost no longer possess luminous effect when diameter of particle is following less than 1 μ m, thereby causes powder granularity wide, the inefficacy incandescnet particle is on the high side.If purely adopt airflow crash, although the degree that wrecks of lattice significantly is lower than ball milling so, but, since before being put to comminution by gas stream for want of to the dismission process of agglomerating particles, thereby, powder self bump differs greatly, and causes discontinuity, so can produce equally the shortcoming of ball milling; They are four years old, by shown in Figure 5, owing in cleaning step, usually will stir through the container that broken powder (dry powder) is introduced with agitator, after leaving standstill clarification, anhydrate, and repeatedly for several times, thereby in this process, objectively be difficult to ultrafine powder and macrobead footpath powder are removed, thereby cause size distribution wide, because ultrafine powder (particle diameter≤1 μ m) does not have luminous efficacy; Its five since will clean and drying after powder only sieve by the 100-250 mesh sieve, packing at once, thereby cause and have fine grain size and the large particle diameter powder phenomenon that coexists in the yellow-green fluorescence powder specifically can be referring to Fig. 6.

In view of above-mentioned prior art, be necessary to be improved, for this reason, the applicant has done positive and useful making repeated attempts, and technical scheme described below produces under this background.

Summary of the invention

Task of the present invention is to provide a kind of and helps to select pointedly the substrate material of relatively concentrating with size distribution and use and satisfy the fluorescent material requirement that preparation has good primary characteristic and quadratic behavior, be conducive to control the activator water ratio and use and ensure that fluorescent material has desirable lattice pattern and uses and improve luminous intensity and thermostability, be of value to the homogeneity that the crystal grain that improves fluorescent material distributes and use to improve luminous efficiency and have and be convenient to promote substrate material, activator and fusing assistant three's mixed effect and use and ensure that the powder granularity make is evenly distributed, lattice complete shape and appearance and having is good at the LED that abandons the inefficacy incandescnet particle and controlled the particle distribution scope with the preparation method of yellow-green fluorescence powder.

Task of the present invention is finished like this, a kind of LED preparation method of yellow-green fluorescence powder, the step that the method comprises is followed successively by batching, batch mixing, burn till, broken, clean, oven dry and the packing of sieving, wherein, described batching is for to take by weighing substrate material by mass percent, take by weighing activator and take by weighing fusing assistant, be characterised in that: before described batching step, have additional the pre-process step, this pre-process step comprises described substrate material screening, be re-dubbed compound fusing assistant to described activator dehumidifying with to described fusing assistant, described batch mixing is will drop in the three-dimensional motion mixer with compound fusing assistant through the activator of dehumidifying first to mix, and the speed of mainshaft of control mixing time and control three-dimensional motion mixer, obtain Preblend, again Preblend is introduced in the three-dimensional motion mixing tank jointly with the substrate material of screening and mixed, and the speed of mainshaft of the mixing time of control three-dimensional motion mixing tank and control three-dimensional motion mixing tank obtains material to be burnt till; Described fragmentation be with by described burn till that step obtains burn till powder first by the vibratory screening apparatus screening, again by the screening of ultrasonic wave sizing screen, then introduce micronizer mill and pulverize, obtain powder to be cleaned, and the intake pressure of control micronizer mill and go out atmospheric pressure; Described cleaning is described powder to be cleaned to be introduced to clean in the classification of sedimentation device clean and classification, obtains the powder to be dried of classification; Described sieving is that the powder that will be obtained by baking step carries out the product grading classification by the air classification sieve, behind packaging step, obtains LED yellow-green fluorescence powder.

In a specific embodiment of the present invention, described substrate material screening is to adopt airflow classification to be sieved into the Three Estate that particle diameter is 1-4.4 μ m, 4.5-6.5 μ m and 6.6-10 substrate material; Described dehumidifying is activator to be inserted in the baking oven cure to activator, and controls stoving temperature and cure the time, and the water ratio of control activator.

In another specific embodiment of the present invention, the mixing time of described control three-dimensional motion mixer is that mixing time is controlled to be 3-4h, and the speed of mainshaft of described control three-dimensional motion mixer is that the speed of mainshaft is controlled to be 8-12r/min; The mixing time of described control three-dimensional motion mixing tank is controlled to be 10-20h, and the speed of mainshaft of described control three-dimensional motion mixing tank is that the speed of mainshaft is controlled to be 12-18r/min.

In another specific embodiment of the present invention, described substrate material is Al ₂O ₃, Lu ₂O ₃And Ga ₂O ₃Mixture; Described activator is CeO ₂Described compound fusing assistant is H ₃BO ₃, BaF ₂, AlF ₂And SrF ₂Composition.

In another specific embodiment of the present invention, described control stoving temperature is that temperature is controlled to be 100-120 ℃, the described control time of curing is that the time is controlled to be 60-240min, and the water ratio of described control activator is to be 0.05-0.5% with moisture control.

Also has in the specific embodiment described Al of the present invention ₂O ₃Mass percent be 13-25%, described Lu ₂O ₃Mass percent be 60-72.5%, described Ga ₂O ₃Mass percent be 2-14%, described CeO ₂Mass percent be 0.3-5.8%; Described by H ₃BO ₃, BaF ₂, AlF ₂And SrF ₂The mass percent of the composition that consists of is 0.18-7.18%, wherein: described H ₃BO ₃Mass percent be 7-25%, described BaF ₂Mass percent be 25-48%, described AlF ₂Mass percent be 25-41%, described SrF ₂Mass percent be 4-25%.

More of the present invention and in specific embodiment, the order number of described vibratory screening apparatus is the 200-250 order; The order number of described ultrasonic wave sizing screen is the 300-500 order, and it is the D that gets by the ultrasonic wave classification sieve that described micronizer mill is pulverized ₅₀Particle diameter is that the powder of 10-20 μ m is crushed to D ₅₀Particle diameter is the powder of 7-8 μ m, and the intake pressure of described control micronizer mill is that intake pressure is controlled to be 0.8-1.2MPa with going out atmospheric pressure, and the pressure-controlling of will giving vent to anger is 0.4-0.8MPa.

In of the present invention and then specific embodiment, described cleaning classification of sedimentation device comprises a stirred vessel with agitator; One first drawing mechanism, one second drawing mechanism and one the 3rd drawing mechanism, the first drawing mechanism comprises the first timing control valve, the first extraction pump, the first bucket and the first pipeline, the first timing control valve and the first extraction pump are connected to the middle part of the first pipeline in turn, one end of the first pipeline is connected with the top of the short transverse of stirred vessel, and the other end of the first pipeline is stretched in the first bucket, wherein, the first timing control valve is between stirred vessel and the first extraction pump, the second drawing mechanism comprises the second timing control valve, the second extraction pump, the second bucket and the second pipeline, the second timing control valve and the second extraction pump are connected to the middle part of the second pipeline in turn, one end of the second pipeline is connected with the middle part of the short transverse of stirred vessel, and the other end of the second pipeline is stretched in the second bucket, wherein, the second timing control valve is between stirred vessel and the second extraction pump, the 3rd drawing mechanism comprises the 3rd timing control valve, the 3rd extraction pump, the 3rd bucket and the 3rd pipeline, the second timing control valve and the second extraction pump are connected to the middle part of the 3rd pipeline in turn, one end of the 3rd pipeline is connected with the bottom of the short transverse of stirred vessel, and the other end of the 3rd pipeline is stretched in the 3rd bucket, wherein, the 3rd timing control valve is between stirred vessel and the 3rd extraction pump.

Of the present invention again more and in specific embodiment, described to carry out the product grading classification by the air classification sieve be the powder that described baking step obtains to be divided to sift out particle size distribution range be D ₁₀=3-5 μ m, D ₅₀=7-8 μ m and D ₉₀The finished product powder of=10-12 μ m.

Technical scheme provided by the invention is owing to sieved before batch mixing substrate material, thereby being put to follow-up batch mixing step, jointly mixes with activator and fusing assistant the substrate material that can select size distribution relatively to concentrate, be evenly distributed with the powder granularity that satisfies preparation, the lattice complete shape and appearance, final so that fluorescent material has excellent primary characteristic and quadratic behavior; Because activator is dehumidified, thereby effectively controlled the activator water ratio and ensured that fluorescent material has desirable lattice pattern and improves luminous efficiency and thermostability (fading rate of light), make the fluorescent material brightness of making improve 5-10%, the fading rate of light has reduced 10-20%; Because fusing assistant is re-dubbed composite fluxing agent, thereby can reduce firing temperature in the step in follow-up burning till, firing temperature is reduced to 1400-1500 ℃ by the 1550-1650 in the prior art ℃, not only can prolong the work-ing life of firing furnace, and embody energy-conservationly, and can effectively control the hardness of firing powder in addition, improved in the powder last handling process owing to the excessive lattice damage that causes of the hardness of powder, promote the crystal grain distributing homogeneity of fluorescent material, improved the luminous efficiency of fluorescent material; Because the Preblend that activator and fusing assistant are mixed to get mutually mixes with substrate material again, and adopt three-dimensional motion mixing method batch mixing, thereby can obtain desirable mixed effect, make and make powder granularity and be evenly distributed, the lattice complete shape and appearance, and owing to abandoned the inefficacy incandescnet particle and controlled the particle distribution scope, ensure fully that therefore the yellow-green fluorescence powder that obtains has very good primary characteristic and quadratic behavior.

Description of drawings

Fig. 1 is the substrate material Al that commercially available channel is bought ₂O ₃Scanning electron microscope (SEM) photograph.

Fig. 2 is with the scanning electron microscope (SEM) photograph of substrate material, activator and the disposable mixed compound of fusing assistant three in the prior art.

Fig. 3 is the scanning electron microscope (SEM) photograph of the yellow-green fluorescence powder in the prior art.

Fig. 4 is the particle distribution figure of the window of tube light powder that obtains behind the ball milling in the prior art.

Fig. 5 is the phosphor particles distribution plan after cleaning in the prior art.

Fig. 6 is to the scanning electron microscope (SEM) photograph of the powder after the oven dry after sieving by the 100-250 mesh sieve in the prior art.

Fig. 7 is that the inventive method is to substrate material Al ₂O ₃Adopt the scanning electron microscope (SEM) photograph after the airflow classification sieve sieves.

To be the inventive method mix rare earth activators and fusing assistant first the scanning electron microscope (SEM) photograph of the compound that obtains after by the three-dimensional motion mixing tank substrate material being participated in mixing again by means of three-dimensional motion mixer to Fig. 8.

Fig. 9 is the phosphor particles distribution plan that obtains after the inventive method fragmentation.

Figure 10 is the phosphor particles distribution plan after the inventive method is cleaned.

Figure 11 is the used cleaning classification of sedimentation device synoptic diagram of the inventive method.

To be the inventive method carry out the scanning electron microscope (SEM) photograph of the yellow-green colour powder that the product grading classification obtains to the powder after the oven dry to Figure 12.

Embodiment

Embodiment 1:

Ask for an interview Fig. 7 to Figure 12.

LED may further comprise the steps with the preparation method of yellow-green fluorescence powder: batching, batch mixing, burn till, broken, clean, dry and sieve, wherein: described batching is for to take by weighing substrate material, take by weighing activator and to take by weighing fusing assistant by mass percent, and substrate material is Al ₂O ₃, Lu ₂O ₃And Ga ₂O ₃Mixture, Al wherein ₂O ₃The mass percent of (through screening) is 25%, Lu ₂O ₃Mass percent be 60%, Ga ₂O ₃Mass percent be 2.2%, activator is CeO ₂, this CeO ₂Mass percent be 5.8%, fusing assistant is H ₃BO ₃, BaF ₂, AlF ₂And SrF ₂Composition, i.e. compound fusing assistant, the mass percent of this compound fusing assistant is 7%, wherein: H in the compound fusing assistant ₃BO ₃Mass percent be 25%, BaF ₂Mass percent be 46%, AlF ₂Mass percent be 25%, SrF ₂Mass percent be 4%.As the technical essential of technical scheme provided by the invention, before entering batching to the Al of aforementioned substrate material ₂O ₃, to activator CeO ₂And to fusing assistant namely by H ₃BO ₃, BaF ₂And AlF ₂And SrF ₂The compound fusing assistant that consists of carries out pre-process, and that is to say increased the pre-process step before batching step, specifically: with Al ₂O ₃Adopt the airflow classification screening to sieve into the Three Estate that particle diameter is 1-4.4 μ m, 4.5-6.5 μ m and 6.6-10 μ m (present embodiment is selected 4.5-6.5 μ m grade), from this Three Estate, choose the Al of one of them grade when producing the different yellow fluorescent powder that requires ₂O ₃, the Al after the screening of airflow classification sieve ₂O ₃The particle diameter degree of uniformity can be illustrated by Fig. 7; Be CeO with activator ₂Send into oven-baked and namely dehumidify, oven temperature is 120 ℃, and the time of curing is 200min, and going out baking oven, to obtain water ratio be 0.2% activator; First with fusing assistant namely by H ₃BO ₃, BaF ₂And AlF ₂And SrF ₂The composition that mixes is compound fusing assistant and activator CeO ₂Together drop in the three-dimensional motion mixer and mix, three-dimensional motion mixer is preferred, but not limited to and selects the model of being produced by the long-range mechanical company limited in Chinese Guangdong province Shenzhen is SYH-200 type Multidirectional motion mixing tank, mixing time is 3h, the speed of mainshaft of this Multidirectional motion mixing tank is 10r/min, obtain Preblend, the substrate material Al that is 4.5-6.5 μ m with Preblend and aforesaid screening particle diameter grade again ₂O ₃, and equally as the Lu of substrate material ₂O ₃And Ga ₂O ₃Drop in the three-dimensional motion mixing tank and mix 20h, the speed of mainshaft of three-dimensional motion mixing tank is controlled to be 15r/min, in the present embodiment, described three-dimensional motion mixing tank is preferred, but not limited to and selects the model of being produced by the long-range mechanical company limited in Chinese Guangdong province Shenzhen equally is SYH-800 type Multidirectional motion mixing tank, obtain the particle diameter of material to be burnt till by shown in Figure 8

The SYH-200 type of mentioning in the present embodiment and SYH-800 type Multidirectional motion mixing tank by main shaft passive and universal joint supporting mixing tank to do three-dimensional motion at X, Y and Z-direction, mixing tank is also made revolution motion except spinning motion, make the material in the mixing tank make every now and then diffusional flow and shearing motion, strengthened to best the mixed effect of material, three-dimensional motion because of mixing tank, overcome the impact that produces centrifugal force when adopting rotary container or stir shaft type stirred vessel to mix in the prior art, reduce the material gravity segregation, thereby guaranteed mixed effect.Embodied all sidedly applicant's alleged technique effect in the technique effect hurdle.

Will to introduce first the order number be that 200 purpose vibratory screening apparatuss are the moto-vibro screen screening by the powder that burns till that burns till that step obtains, screened by ultrasonic wave sizing screen (also claiming the ultrasonic vibration sizing screen) again, the order number of ultrasonic wave sizing screen is 500 orders, make the particle diameter of powder be controlled to be 10-20 μ m, then introducing micronizer mill pulverizes, micronizer mill is preferred, but not limited to and uses the model of being produced by the pioneer of Changshu City, Jiangsu Province, China machinery company limited to be GTM-400 type pulverizer, this micronizer mill is ceramic-lined flat pulverizer, make the D50 particle diameter of powder be controlled to be 7-8 μ m, advancing of micronizer mill, go out atmospheric pressure and be respectively 0.8MPa and 0.4MPa, obtaining powder to be cleaned after being pulverized by micronizer mill is that phosphor particles is illustrated by Fig. 9.

Utilization is cleaned the powder aforementioned to be cleaned that obtains after being pulverized by micronizer mill by the cleaning classification of sedimentation device of Figure 11, and the applicant at first describes the structure of cleaning the classification of sedimentation device, comprises a stirred vessel 1 with agitator 11; One first drawing mechanism 2, one second drawing mechanism 3 and one the 3rd drawing mechanism 4, the first drawing mechanism 2 comprises the first timing control valve 21, the first extraction pump 22, the first bucket 23 and the first pipeline 24, the first timing control valve 21 and the first extraction pump 22 are connected to the middle part of the first pipeline 24 in turn, one end of the first pipeline 24 is connected with the top of the short transverse of stirred vessel 1, and the other end of the first pipeline 24 is stretched in the first bucket 23, wherein, the first timing control valve 21 is between stirred vessel 1 and the first extraction pump 22, the second drawing mechanism 3 comprises the second timing control valve 31, the second extraction pump 32, the second bucket 33 and the second pipeline 34, the second timing control valve 31 and the second extraction pump 32 are connected to the middle part of the second pipeline 34 in turn, one end of the second pipeline 34 is connected with the middle part of the short transverse of stirred vessel 1, and the other end of the second pipeline 34 is stretched in the second bucket 33, wherein, the second timing control valve 31 is between stirred vessel 1 and the second extraction pump 32, the 3rd drawing mechanism 4 comprises the 3rd timing control valve 41, the 3rd extraction pump 42, the 3rd bucket 43 and the 3rd pipeline 44, the second timing control valve 41 and the second extraction pump 42 are connected to the middle part of the 3rd pipeline 44 in turn, one end of the 3rd pipeline 44 is connected with the bottom of the short transverse of stirred vessel 1, and the other end of the 3rd pipeline 44 is stretched in the 3rd bucket 43, wherein, the 3rd timing control valve 41 is between stirred vessel 1 and the 3rd extraction pump 32.The applicant describes method or the title process that powder is implemented cleaning of cleaning for the treatment of: powder to be cleaned is introduced in the stirred vessel 1, and introduce deionized water (filling into the ratio of 4 liters of deionized waters in kilogram fluorescent material per kilogram) turn on agitator 11, the rotating speed of agitator is 15-20r/min, after agitator stirs 25-35min, open the first timing control valve 21 of the first drawing mechanism 2 according to sequencing, 22 work of the first extraction pump, the powder slurry solution on the top in the stirred vessel 1 is introduced in the first bucket 23 through the first pipeline 24, then open the second timing control valve 31 of the

second drawing mechanism

3,32 work of the second extraction pump, the powder slurry solution that is positioned at the middle part in the stirred vessel 1 is introduced the second bucket 33 through the second pipeline 34, then open the 3rd timing control valve 41 of the 3rd drawing mechanism 4,42 work of the 3rd extraction pump are introduced the 3rd bucket 43 with the powder slurry solution that is positioned at the bottom in the stirred vessel 1 through the 3rd pipeline 44.Then, the slurry of the powder in first, second, third bucket 23,33,43 is introduced respectively whizzer dry, the phosphor particles distribution scenario after the cleaning that the powder to be dried that obtains namely obtains is by shown in Figure 10.This step is the principle that has different settling velocity according to different diameter of particle, the slurries that extracted by the first drawing mechanism 2 namely are arranged in the slurries on stirred vessel 1 top because powder granularity is ultra-fine and be mingled with the foreign material that cleaning process produces, therefore usually that it is discarded, and be normal powder (finished powder) by what the second drawing mechanism 3 extracted, and the diameter of particle that is namely extracted by the 3rd drawing mechanism 4 of lower floor is larger, uses after needing again to process.Accordingly, phosphor particles distribution scenario shown in Figure 10 is for by the second drawing mechanism 3 powders that extract and behind centrifuge dripping.

The powder to be dried of the classification that obtains after above-mentioned cleaning is dried according to the same process in the prior art, and the rear packing of sieving, yet as technical essential of the present invention: the powder that baking step is obtained carries out the product grading classification by the air classification sieve, minute gets D ₁₀=3-5 μ m, D ₅₀=7-8 μ m and D ₉₀=10-12 μ m, obtain the high-quality powder of size distribution high concentration, it is even to that is to say that the yellow-green colour powder to be packaged that obtains after the air classification sieve carries out the product grading classification has size of particles, without agglomeration and lattice perfection, is specifically illustrated by Figure 12 between the particle.

The resulting LED of present embodiment has the strong point of narrow diameter distribution with the yellow-green fluorescence powder, compare with the yellow-green fluorescence powder of prior art, by analysis test: brightness improves 3-5%, the particle diameter uniformity coefficient improves more than 30%, lattice imperfection reduces about 30%, thereby can reduce light decay and the look drift of fluorescent material, improve thermostability.

Embodiment 2:

Only will be through the Al of screening ₂O ₃Mass percent change 13% into, with Lu ₂O ₃Mass percent change 72.5% into, with Ga ₂O ₃Mass percent change 14% into, with CeO ₂Mass percent be 0.3%, will be by H ₃BO ₃, BaF ₂And AlF ₂The composition that consists of is that the mass percent of compound fusing assistant changes 0.2% into, wherein: H ₃BO ₃Mass percent change 8%, BaF into ₂Mass percent change 40%, AlF into ₂Mass percent change 41%, SrF into ₂Mass percent change 11% into; Al ₂O ₃Get the particle diameter grade of 6.6-10 μ m; To CeO ₂Stoving temperature and time change respectively 100 ℃ and 240min, CeO into ₂Water ratio be 0.07%; Change the mixing time of compound fusing assistant and activator into 4h, the speed of mainshaft of three-dimensional motion mixer is that the speed of mainshaft of Multidirectional motion mixing tank changes 8r/min into, is that the substrate material of 6.6-10 μ m is Al with Preblend and particle diameter ₂O ₃And same Lu as substrate material ₂O ₃And Ca ₂O ₃Mixing time change 10h into, the speed of mainshaft of three-dimensional motion mixing tank changes 18r/min into; Change the order number of vibratory screening apparatus into 250 orders, change the order number of ultrasonic wave sizing screen into 300 orders, change respectively the inlet, outlet pressure of micronizer mill into 1.2MPa and 0.8MPa, all the other are all with the description to embodiment 1.

Embodiment 3:

Only will be through the Al of screening ₂O ₃Mass percent change 20% into, with Lu ₂O ₃Mass percent change 65% into, with Ga ₂O ₃Mass percent change 8% into, with CeO ₂Mass percent be 2.5%, will be by H ₃BO ₃, BaF ₂And AlF ₂The composition that consists of is that the mass percent of compound fusing assistant changes 4.5% into, wherein: H ₃BO ₃Mass percent change 10%, BaF into ₂Mass percent change 35%, AlF into ₂Mass percent change 30%, SrF into ₂Mass percent change 25% into; Al ₂O ₃Get the particle diameter grade of 1-4.4 μ m; To CeO ₂Stoving temperature and time change respectively 110 ℃ and 70min, CeO into ₂Water ratio be 0.5%; Change the mixing time of compound fusing assistant and activator into 3.5h, the speed of mainshaft of three-dimensional motion mixer is that the speed of mainshaft of Multidirectional motion mixing tank changes 12r/min into, is that the substrate material of 1-4.4 μ m is Al with Preblend and particle diameter ₂O ₃And same Lu as substrate material ₂O ₃And Ca ₂O ₃Mixing time change 15h into, the speed of mainshaft of three-dimensional motion mixing tank changes 13r/min into; Change the order number of vibratory screening apparatus into 220 orders, change the order number of ultrasonic wave sizing screen into 400 orders, change respectively the inlet, outlet pressure of micronizer mill into 1MPa and 0.6MPa, all the other are all with the description to embodiment 1.

Claims

1. A kind of LED preparation method of yellow-green fluorescence powder, the step that the method comprises is followed successively by batching, batch mixing, burn till, broken, clean, oven dry and the packing of sieving, wherein, described batching is for to take by weighing substrate material by mass percent, take by weighing activator and take by weighing fusing assistant, it is characterized in that: before described batching step, have additional the pre-process step, this pre-process step comprises described substrate material screening, be re-dubbed compound fusing assistant to described activator dehumidifying with to described fusing assistant, described batch mixing is will drop in the three-dimensional motion mixer with compound fusing assistant through the activator of dehumidifying first to mix, and the speed of mainshaft of control mixing time and control three-dimensional motion mixer, obtain Preblend, again Preblend is introduced in the three-dimensional motion mixing tank jointly with the substrate material of screening and mixed, and the speed of mainshaft of the mixing time of control three-dimensional motion mixing tank and control three-dimensional motion mixing tank obtains material to be burnt till; Described fragmentation be with by described burn till that step obtains burn till powder first by the vibratory screening apparatus screening, again by the screening of ultrasonic wave sizing screen, then introduce micronizer mill and pulverize, obtain powder to be cleaned, and the intake pressure of control micronizer mill and go out atmospheric pressure; Described cleaning is described powder to be cleaned to be introduced to clean in the classification of sedimentation device clean and classification, obtains the powder to be dried of classification; Described sieving is that the powder that will be obtained by baking step carries out the product grading classification by the air classification sieve, behind packaging step, obtain LED yellow-green fluorescence powder, described cleaning classification of sedimentation device comprises a stirred vessel with agitator (11) (1); One first drawing mechanism (2), one second drawing mechanism (3) and one the 3rd drawing mechanism (4), the first drawing mechanism (2) comprises the first timing control valve (21), the first extraction pump (22), the first bucket (23) and the first pipeline (24), the first timing control valve (21) and the first extraction pump (22) are connected to the middle part of the first pipeline (24) in turn, one end of the first pipeline (24) is connected with the top of the short transverse of stirred vessel (1), and the other end of the first pipeline (24) is stretched in the first bucket (23), wherein, the first timing control valve (21) is positioned between stirred vessel (1) and the first extraction pump (22), the second drawing mechanism (3) comprises the second timing control valve (31), the second extraction pump (32), the second bucket (33) and the second pipeline (34), the second timing control valve (31) and the second extraction pump (32) are connected to the middle part of the second pipeline (34) in turn, one end of the second pipeline (34) is connected with the middle part of the short transverse of stirred vessel (1), and the other end of the second pipeline (34) is stretched in the second bucket (33), wherein, the second timing control valve (31) is positioned between stirred vessel (1) and the second extraction pump (32), the 3rd drawing mechanism (4) comprises the 3rd timing control valve (41), the 3rd extraction pump (42), the 3rd bucket (43) and the 3rd pipeline (44), the second timing control valve (41) and the second extraction pump (42) are connected to the middle part of the 3rd pipeline (44) in turn, one end of the 3rd pipeline (44) is connected with the bottom of the short transverse of stirred vessel (1), and the other end of the 3rd pipeline (44) is stretched in the 3rd bucket (43), wherein, the 3rd timing control valve (41) is positioned between stirred vessel (1) and the 3rd extraction pump (32).

2. LED according to claim 1 is characterized in that with the preparation method of yellow-green fluorescence powder described substrate material screening is to adopt airflow classification to be sieved into the Three Estate that particle diameter is 1-4.4 μ m, 4.5-6.5 μ m and 6.6-10 substrate material; Described dehumidifying is activator to be inserted in the baking oven cure to activator, and controls stoving temperature and cure the time, and the water ratio of control activator.

3. The LED according to claim 1 preparation method of yellow-green fluorescence powder, the mixing time that it is characterized in that described control three-dimensional motion mixer is that mixing time is controlled to be 3-4h, and the speed of mainshaft of described control three-dimensional motion mixer is that the speed of mainshaft is controlled to be 8-12r/min; The mixing time of described control three-dimensional motion mixing tank is controlled to be 10-20h, and the speed of mainshaft of described control three-dimensional motion mixing tank is that the speed of mainshaft is controlled to be 12-18r/min.

4. LED according to claim 1 is characterized in that with the preparation method of yellow-green fluorescence powder described substrate material is Al ₂ O ₃ , Lu ₂ O ₃ And Ga ₂ O ₃ Mixture; Described activator is CeO ₂ Described compound fusing assistant is H ₃ BO ₃ , BaF ₂ , AlF ₃ And SrF ₂ Composition.

5. The LED according to claim 2 preparation method of yellow-green fluorescence powder, it is characterized in that described control stoving temperature is that temperature is controlled to be 100-120 ℃, the described control time of curing is that the time is controlled to be 60-240min, and the water ratio of described control activator is to be 0.05-0.5% with moisture control.

6. LED according to claim 4 is characterized in that described Al with the preparation method of yellow-green fluorescence powder ₂ O ₃ Mass percent be 13-25%, described Lu ₂ O ₃ Mass percent be 60-72.5%, described Ga ₂ O ₃ Mass percent be 2-14%, described CeO ₂ Mass percent be 0.3-5.8%; Described by H ₃ BO ₃ , BaF ₂ , AlF ₃ And SrF ₂ The mass percent of the composition that consists of is 0.18-7.18%, wherein: described H ₃ BO ₃ Mass percent be 7-25%, described BaF ₂ Mass percent be 25-48%, described AlF ₃ Mass percent be 25-41%, described SrF ₂ Mass percent be 4-25%.

7. The LED according to claim 1 preparation method of yellow-green fluorescence powder, the order number that it is characterized in that described vibratory screening apparatus is the 200-250 order; The order number of described ultrasonic wave sizing screen is the 300-500 order, and it is the D that gets by the ultrasonic wave classification sieve that described micronizer mill is pulverized ₅₀ Particle diameter is that the powder of 10-20 μ m is crushed to D ₅₀ Particle diameter is the powder of 7-8 μ m, and the intake pressure of described control micronizer mill is that intake pressure is controlled to be 0.8-1.2MPa with going out atmospheric pressure, and the pressure-controlling of will giving vent to anger is 0.4-0.8MPa.

8. LED according to claim 1 is with the preparation method of yellow-green fluorescence powder, it is characterized in that described to carry out the product grading classification by the air classification sieve be the powder that described baking step obtains to be divided to sift out particle size distribution range be D ₁₀ =3-5 μ m, D ₅₀ =7-8 μ m and D ₉₀ The finished product powder of=10-12 μ m