Title: the LED encapsulation method of fluorescent material being carried out to dispersion treatment
Summary of the invention
The technical problem to be solved in the present invention is to provide a kind of LED encapsulation method of fluorescent material being carried out to dispersion treatment, it is for solving the problem of the rear fluorescent material skewness in arogel of arogel solidification, and the LED arogel of a kind of anti-fluorescent material precipitation that the method relates to also is for solving this technical problem.
For solving the problem, the present invention proposes a kind of LED encapsulation method of fluorescent material being carried out to dispersion treatment,
The mixture adding fluorescent material and doping in mixed arogel makes arogel, and described doping comprises being heated releases water thing and hydroscopic high-molecular resin SAP powder, described in be heated and release in process that water thing is heating and curing at arogel and can discharge hydrone;
In arogel, be mixed into curing agent, LED chip puts glue;
Then heat, make to be heated and release water thing release hydrone, hydroscopic high-molecular resin absorbs this hydrone and expands, and the hydroscopic high-molecular resin after expansion carries fluorescent material, and fluorescent material is disperseed in arogel, solidifies to arogel.
The arogel composition that the present invention relates to comprises mixed arogel, fluorescent material, is heated and releases water thing and hydroscopic high-molecular resin; Wherein be heated release water thing and hydroscopic high-molecular resin ratio requirement when mixed arogel is in package curing process, be heated release water thing release the water yield absorbed by hydroscopic high-molecular resin.The component ratio of releasing water thing and hydroscopic high-molecular resin of being heated can carry out modulating ligand ratio according to actual needs and determine, does not generally produce the water of surplus.Doping can also comprise stabilizer and dispersant.Arogel coordinates fixative to use.Mixed arogel can be epoxy resin and silica gel, can also be other encapsulation colloid.
Preferably: described in be heated and release water thing and to comprise in crystalline hydrate, oxide hydrate and organic substance hydrate one or more.
Preferably: described in be heated and release water thing and comprise seven water nickelous sulfates, white vitriol, epsom salt, Sodium Citrate, usp, Dihydrate Powder, kaolin, barium chloride, calcium sulphate dihydrate, alum, saltcake, blue stone, green-vitriol, nine water sodium metasilicate, chloral hydrate, Co (ClO4)26H2o and [Cr (H2o)4cl2] Cl2H2one or more mixing in O.
Preferably: described SAP is Sodium Polyacrylate or polyethyleneglycol diacrylate.
Preferably: described doping comprises stabilizer and dispersant.
Preferably: after being mixed with arogel, arogel is ground to the requirement reaching granularity.
Preferably: described LED chip is the through-hole vertical structure LED without the need to beating gold thread, and its surface has passivation layer.
Preferably: described fluorescent material is yellow fluorescent powder, described LED chip is blue chip, and blue chip excites yellow fluorescent powder to send white light.
Preferably: described fluorescent material is one or more the mixing in yellow fluorescent powder, red light fluorescent powder, blue light fluorescent powder or green light fluorescent powder.
This beneficial effect of the invention:
Compared to existing technology, the present invention adds as released pigment end and SAP imbibition material in arogel, in the process of arogel by hot curing, release pigment end and discharge hydrone, this hydrone is by SAP particle absorption, SAP particle volume sharply expands, in the process of SAP particle expansion, the fluorescent material that SAP particle carries also is followed and to be distributed in arogel everywhere, now, SAP particle can form a kind of obstruction to the flowing of fluorescent material, and due to it, certain supporting role is played to phosphor particles, phosphor particles is not easy to precipitate under gravity, when arogel has solidified, fluorescent material to be just evenly distributed in arogel everywhere.The invention solves the problem of the fluorescent material skewness in LED device, which raises the utilance of fluorescent material, the light color that device is sent is more even, and better effects if, quality is higher.
Embodiment
The present invention proposes a kind of LED encapsulation method of fluorescent material being carried out to dispersion treatment, the mixture adding fluorescent material and doping in mixed arogel makes arogel, doping comprises being heated and releases water thing and hydroscopic high-molecular resin SAP powder, is heated and releases in process that water thing is heating and curing at arogel and can discharge hydrone; In arogel, be mixed into curing agent, LED chip puts glue; Then heat, make crystalline hydrate discharge hydrone, hydroscopic high-molecular resin absorbs this hydrone and expands, and the hydroscopic high-molecular resin after expansion carries fluorescent material, and fluorescent material is disperseed in arogel, solidifies to arogel.
The arogel composition that the present invention relates to is important feature of the present invention.It is a kind of LED arogel of anti-fluorescent material precipitation, and this arogel comprises mixed arogel, fluorescent material, is heated and releases water thing and hydroscopic high-molecular resin composition.The component ratio of releasing water thing and hydroscopic high-molecular resin of being heated can carry out modulating ligand ratio according to actual needs and determine.Doping can also comprise stabilizer and dispersant.Arogel coordinates fixative to use.The present invention also proposes a kind of LED device using above-mentioned arogel.
The present invention is described in detail by the following examples, and step is shown in Figure 2.
First select fluorescent material, be heated release water thing, the powder of hydroscopic high-molecular resin (be called for short SAP) mixes with epoxy resin.
LED chip selects blue chip, and fluorescent material is the Yttrium aluminium garnet (YAG) type rare earth compound and the YAG that excite gold-tinted.This fluorescent material can keep stable state at 300 °.The type of LED chip is optional, and according to the emission type of LED chip, fluorescent material can also be TAG, and other excites the fluorescent material of shades of colour, as three primary colors mixed fluorescent powder, violet, pink etc.
Being heated and releasing water thing is saltcake.The molecular formula of saltcake is Na2sO412H2o, its 32.38 degrees Celsius start dehydration, and 100 degrees Celsius are dewatered completely.If releasing water thing so be heated is saltcake, then arogel can ensure that within the scope of the curing temperature of 110-180 degree Celsius water-absorbing resin expansion is stable.
Be heated and release water thing and be not limited to saltcake, also can select seven water nickelous sulfates, white vitriol (alum), epsom salt, barium chloride;
Sodium Citrate, usp, Dihydrate Powder, and other salt, citric acid monohydrate sodium generally starts dehydration at 70 °-75 °;
Kaolin, kaolin Main Ingredients and Appearance is hydrated alumina/silica, and it starts dehydration at 40 to 60 degree, occurs comparatively significantly to dewater when 110 degree;
Calcium sulphate dihydrate (gypsum), it starts to be dehydrated into semi-hydrated gypsum at 152 °, and semi-hydrated gypsum presents comparatively strong basicity, and therefore releasing water material as being heated not is good selection;
Alum, it starts dehydration at 64.5 °, and about 92.5 degree start to lose 9 hydrones, and it just can lose 12 whole hydrones at 200 °, and therefore, under general arogel curing temperature, alum dehydration is imperfect;
Blue stone, presents blueness under normal temperature, starts to lose 4 hydrones under 113 °, and present white or colourless, just can slough last hydrone when 258 °, therefore, it can not dewater completely in arogel setting up period simultaneously;
Green-vitriol, also known as green vitriol, in green under normal temperature, 64 ° start dehydration, present white or colourless after dehydration, 300 ° can slough 20% water, not exclusively dewater to be heated for one and release water material;
Nine water sodium metasilicate, are commonly called as waterglass, and 100 ° can be dewatered completely;
Chloral hydrate, Co (ClO4)26H2o and [Cr (H2o)4cl2] Cl2H2o.
Saltcake can also mix with above-mentioned alternative material and release water thing as being heated.Above-mentioned being heated is released water material and is namely heated that to release water thing can be single compound, also can be their one or more mixture.Wherein present acidity or alkalescence after some material dehydration, therefore selecting it to release water material as being heated should be careful, in order to avoid have a negative impact, affects performance and the life-span of LED component.
Above-mentioned exemplify be heated and release water owner and will classify as crystalline hydrate, oxide water containing thing and organic substance hydrate, they can release water thing as being heated by homogenous material, also can be multiple mixing.
SAP is Sodium Polyacrylate or polyethyleneglycol diacrylate.Because current hydroscopic high-molecular resin is numerous, therefore, the selection of the material of above-mentioned two kinds of compositions is not limited to.Hydroscopic high-molecular resin has not identical expansion multiple according to the difference of its composition.The water yield of expansion multiple also with absorbed is relevant, and expansion multiple more common at present, between 30-1000 times, is preferably the SAP of white, also has yellow SAP.Under LED generates heat environment, still moisture content can be maintained after SAP water suction.Under the encirclement of epoxy resin around, hydrone can not be discharged easily.Even if LED temperature reach 100 ° even more than, the lock water that SAP can be stable.
With fluorescent material, be heated release water thing, SAP configures arogel, powder footpath, the center D50/um of such as fluorescent material is 6.0, then the granular size of the hydroscopic high-molecular resin selected is at 1-2um.This size range the best of fluorescent material is 5-10um, and the granular size of macromolecule resin is 1/10 to ten/3rd of fluorescent material size, but is not limited to this proportion.The particle size releasing water thing of being heated can be screened with reference to the granular size of fluorescent material.
In addition, doping comprises stabilizer and dispersant.They are conducive to the distribution before heating process or in process improving other doping.They can use on a small quantity, also can not use.
After being mixed with arogel, arogel is ground to the requirement reaching granularity.The particle obviously bigger than normal existed in arogel is mainly removed in grinding.Grinding, except improving except granular size, can also make the particle in arogel distribute more uniformly, interlacedly refers and synthesizes and depends on, and even formed lightly crosslinked, this step can improve the distribution situation be entrained in arogel.But this step is optional.
After having ground, then be mixed into curing agent stirring, then put glue, by arogel point in the bowl cup of LED chip.
See Fig. 1, LED chip is the through-hole vertical structure LED without the need to beating gold thread, has arogel 2, have SAP particle 3 in arogel 2 in the surface coverage of chip 1, the state expanded after the water suction of this SAP particle 3.Its surface has passivation layer, and passivation layer is optional, and it mainly plays electric leakage, electric action.The structure of chip of the present invention is not limited to structure in Fig. 1, if any beating the structure of gold thread also in protection scope of the present invention.
After some glue completes, arogel is being heated.Present embodiment is carried out at normal temperatures, and ambient temperature is assumed to be 20 degrees centigrade.The temperature of the release hydrone of saltcake starts to discharge hydrone at 32.38 °, heats up gradually to arogel.The hydrone of saltcake release, by SAP particle absorption, expands after the water suction of SAP particle.
Join the volume ratio of glue, if epoxy resin and curing agent (i.e. A glue B glue) proportioning are 1: 1.The fluorescent material wherein adulterated is 0.09 unit, but is not limited to above-mentioned 0.09 unit, such as, can be 0.15 unit, and namely A glue, B glue and fluorescent material also can be 1: 1: 0.15.Saltcake also can be 0.15 unit, and hydroscopic high-molecular resin is 0.05 unit.It should be noted that, the amount of saltcake can adjust as required, and the amount of hydroscopic high-molecular resin also can release according to being heated water thing release the water yield number adjust.
In fact, be heated release water material release the water yield number with material moisture water example itself relevant, also relevant with the temperature of being heated.Different material institute water content is different.Even if same material, under different curing temperatures, the hydrone quantity of release is also different.Such as, alum at 92.5 ° of release, 9 hydrones, and just can lose whole hydrones at 200 °.In addition, also relevant with the time in week, it is longer much to release the time that water material is heated, and the water decomposed out is more.The curing time of general arogel is 1 hour, and curing time is determined by the solidification attribute of epoxy resin.Its consumption is strengthened for the water material require of releasing releasing the water yield little, and its consumption can be reduced to releasing the large material of the water yield.
Also there is a lot of type in hydroscopic high-molecular resin, has different water absorbing capacities and expanding volume.General Water absorption is 100 times, if water absorbing capacity is very strong, 1400 times can be reached as the highest, then can reduce the amount of hydroscopic high-molecular resin further, but in order to be conducive to the distribution of hydroscopic high-molecular resin in arogel, it needs to be processed into the particle of less order number, as 5000 orders (2.6um), even 10,000 orders (1.3um) and more than.The water releasing the release of water thing that is generally heated directly can be adsorbed by hydroscopic high-molecular resin, be suspended in arogel, sharply expand after arogel water suction, fluorescent powder grain is carried to all directions expansion in arogel in its surface, thus fluorescent material is diffused into each corner of arogel, fluorescent material is evenly distributed in arogel very much.
Some develops the color under being heated and releasing water thing normal temperature, as aobvious green under green vitriol normal temperature, but after thermal dehydration, becomes colourless transparent crystal, therefore can not affect the luminescence of LED chip.Generally transformation is not optimized in faintly acid, weakly alkaline water material of releasing for after dehydration, and first-selected neutral material or to chip and the destructive little material of epoxy resin.
Of the present invention being heated releases water thing and hydroscopic high-molecular resin is not limited to the above-mentioned material mentioned, all material alternatives that can be applied to the technology of the present invention are all in protection scope of the present invention.