JP2013004901A - Led device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED device which has a high light extraction efficiency and allows light to be emitted in one direction, thereby obtaining bright light used for illumination, and which has no problem of deterioration and discoloration of a seal material and an internal metal member, and has excellent reliability and durability, the LED device having no problem of damage to a seal material layer during assembly of the device, and having no problem of stickiness of the seal material surface, and the LED device being easy to manufacture.SOLUTION: An LED device 10 includes: a concave-type package 1; an LED element 3 stored in a concave part 2 of the concave-type package 1; and a fluorescent body 4 and a seal material 5 that are loaded in the concave-type package 1. An opening of the concave part 2 of the concave-type package 1 is coated with a silica film 20.

Description

  The present invention relates to an LED (light emitting diode) device, and more particularly to an LED device that has high light extraction efficiency, is excellent in reliability and durability, and is easy to manufacture.

  In recent years, light-emitting diodes (LEDs) are being used as alternatives to various light sources and illumination in terms of power saving, environmental impact, and long life.

  Conventionally, as an LED device, an LED device having a concave package, an LED element housed in a concave portion of the concave package, and a sealing material filled in the concave package is known. However, in this LED device, when the device is assembled, the encapsulant layer for encapsulating the LED element is damaged, or the package sticks on the production line due to the sticky surface of the encapsulant, or the package is contaminated. There was a problem. There are also problems such as oxidation deterioration and discoloration of metal members such as silver wires in the LED device, hydrolysis deterioration due to moisture permeation of the resin as the sealing material, and discoloration due to sulfur adsorption of the resin as the sealing material.

  Further, in an LED device, light emitted from an LED element is generally diffused by a sealing material layer having a phosphor, and wavelength-converted light is extracted. At that time, of the light to be emitted from the light extraction side due to the refractive index of the sealing material layer, the light to be emitted at the critical angle or more to the layer interface is totally reflected and enters the sealing material layer. It is trapped and cannot be taken out. Therefore, improvement of the light extraction efficiency is a big issue.

  Patent Document 1 discloses that a protective layer having a refractive index comparable to that of the light scattering layer is provided in order to prevent external element deterioration factors such as moisture and oxygen from entering the element. . However, in Patent Document 1, the first scattering portion, the second scattering portion, and the protective layer are stacked in multiple layers, and industrialization is difficult in that the number of stacking steps increases.

  Patent Document 2 shows that the entire surface of a light-emitting element is covered with a continuous film made of a hybrid material having a uniform thickness to stabilize optical characteristics, discoloration resistance, and weather resistance. However, the process of covering the entire surface of the light emitting element with the hybrid material film is a very complicated process and difficult to manufacture. Further, in the coating type described in Patent Document 2, light is emitted in multiple directions, and the brightness is insufficient for lighting applications that require extraction of bright light with a high luminous flux density in one desired direction. Met.

JP 2010-97873 A JP 2007-96148 A

  The present invention solves the above-described conventional problems, has high light extraction efficiency, and emits light in one direction, so that bright light can be obtained for illumination use, and a sealing material and an internal metal member can be obtained. There are no problems such as deterioration or discoloration, and it is excellent in reliability and durability. Moreover, there is no problem of damage to the sealing material layer during device assembly, stickiness of the sealing material surface, and easy manufacture. An object is to provide a simple LED device.

  As a result of intensive studies to solve the above-described problems, the present inventors have found that in an LED device in which an LED element is disposed in a concave portion of a concave package and sealed together with a phosphor, a sealing material is used. It has been found that the above-mentioned problem can be solved by providing a silica film in the opening.

  The present invention has been achieved on the basis of such findings, and the gist thereof is as follows.

[1] A concave package, an LED element housed in a concave portion of the concave package, and an LED device having a phosphor and a sealing material filled in the concave package, the opening of the concave portion of the concave package An LED device characterized in that a part is coated with a silica film.

[2] The LED device according to [1], wherein the silica film is a porous film having a porosity of 25% or more, and the refractive index of the silica film is lower than the refractive index of the sealing material. .

[3] The LED device according to [2], wherein the mode gap diameter of the silica film is 0.5 to 10 nm.

[4] The LED device according to any one of [1] to [3], wherein the silica film has a thickness of 60 to 160 nm.

  According to the present invention, by providing the coating film made of silica on the opening of the concave portion of the concave package, that is, the sealing material layer, the light extraction efficiency is high with the following excellent effects. In addition, since light is emitted in one direction, bright light can be obtained for lighting applications, there are no problems such as deterioration or discoloration of the sealing material or internal metal members, and it is excellent in reliability and durability. Thus, there is provided an LED device that is free from the problem of damage to the sealing material layer during device assembly, the problem of stickiness on the surface of the sealing material, and easy to manufacture.

(1) By providing the silica film on the encapsulant layer of the concave package, it is possible to avoid problems that occur during device assembly. For example, the sealing material layer that seals the LED element can be prevented from being damaged during the assembly of the device, and the sticking of the sealing material can cause the device to stick to the production line or cause the device to become dirty. Can be prevented.
(2) Due to the presence of an inorganic material coating layer of silica film on the surface, oxidation degradation and discoloration of metal members such as silver wires, hydrolysis degradation due to moisture permeation of resin as a sealing material, discoloration due to sulfur adsorption of resin Etc. can be prevented.
(3) Silica is not decomposed by light or heat emitted from the LED element and is not easily deteriorated. Further, since no gas or impurities are generated, the element is not contaminated. For this reason, the performance as an LED element is not impaired by the formation of the silica film.
(4) Since silica has a low refractive index, it is possible to extract light efficiently without reflecting light inside the concave package by providing a silica film at the light exit interface.
(5) Since the silica film is provided in the opening of the concave package, the light is not totally reflected in the encapsulant layer and is emitted in one direction from the opening of the concave package. Can be obtained.
(6) The silica film can be formed at a low temperature by a general coating method, and can be easily incorporated into the manufacturing process.
(7) The silica film can achieve a low refractive index with a single layer, does not require a lamination step, and is easy to industrialize.

It is typical sectional drawing which shows an example of embodiment of the LED device of this invention. It is typical sectional drawing which shows the other example of embodiment of the LED device of this invention.

  Embodiments of the LED device of the present invention will be described in detail below with reference to the drawings.

  1 and 2 are schematic cross-sectional views showing embodiments of the LED device of the present invention.

The LED device 10 in FIG. 1 is a package-integrated LED device in which a cup portion 1a for forming a concave portion for accommodating an LED element and a substrate portion 1b for supporting the cup portion 1a are integrally formed. The concave package 1 composed of the portion 1b, the LED element 3 housed in the concave portion 2 of the concave package 1, and the phosphors filled in the concave portion 2 (red phosphor 4A, blue phosphor 4B, green phosphor 4C) ) 4 and the sealing material 5. The LED element 3 is bonded to the bottom of the recess 2 with a die bond material 6. Further, the electrodes 3A and 3B on the upper surface of the LED element 3 and the leads 7A and 7B are electrically connected to each other by the conductive wires 8A and 8B so that electric power is supplied.
The upper surface 5A of the sealing material layer formed by the sealing material 5 including the phosphor 4 filled in the concave portion 2 of the concave package 1 is flush with the upper surface 1A of the concave package 1, and this concave package 1 A silica film 20 is provided so as to cover the upper surface 1A and the upper surface 5A of the sealing material layer.

An LED device 10A shown in FIG. 2 is an LED device in which a cup for forming a concave portion for accommodating an LED element and a substrate that supports the cup are separated, and the concave package 9 includes a cup 9a and a substrate 9b. 1 is different from the LED device 10 of FIG. In FIG. 2, members having the same functions as those in FIG.
Even in this LED device 10 </ b> A, the upper surface 5 </ b> A of the sealing material layer formed by the sealing material 5 including the phosphor 4 filled in the concave portion 2 of the concave package 9 is flush with the upper surface 9 </ b> A of the concave package 9. A silica film 20 is provided so as to cover the upper surface 9A of the concave package 9 and the upper surface 5A of the sealing material layer.

  In the following, the LED element is disposed in the concave portion of the concave package and filled with the phosphor and the sealing material (in FIGS. 1 and 2 before the silica film 20 is formed). May be referred to as an “encapsulated package”.

  In the LED device of the present invention, an LED element is disposed in a concave package, which will be described later, and is electrically connected. Further, a phosphor and a sealing material are filled in the concave portion of the package to produce an encapsulated package. And it can produce by forming a silica film on the package upper surface by the film forming method described later. Moreover, it is also possible to form a silica film on a sealing material layer and a package upper surface of a commercially available encapsulated package by a film forming method described later to obtain the LED device of the present invention.

[Silica film]
First, a silica film (hereinafter sometimes referred to as “the silica film of the present invention”) formed in the LED device of the present invention will be described.

The silica film of the present invention is preferably composed mainly of a silicon oxide (SiO ₂ ) composition.
The silica film has a SiO _x composition (provided that a silicon atom-carbon atom bond is present in a part of the silica composition by a method such as copolymerization of organic silanes in silica synthesis by a sol-gel method, for example. x is a positive number greater than 0 and less than 2).

<Porosity>
The silica film of the present invention is a porous film having a porosity of 25% or more, and preferably has a refractive index lower than that of the sealing material.
When the porosity of the silica film is 25% or more, the refractive index of the silica film can be lowered.
When the refractive index of the silica film is lower than the refractive index of the encapsulant, the light diffused in the encapsulant layer is less likely to be reflected at the interface of the silica film / encapsulant layer and is easily transmitted as refracted light. Therefore, the light extraction efficiency is improved.

  Here, the porosity of the silica film is a ratio occupied by “a gap between silica particles” in the silica film, and can be measured by the following method.

<Measurement method of porosity>
For a sample in which a silica film is formed on a substrate, the refractive index n of the silica film is measured by a spectroscopic ellipsometer, the refractive index of silica constituting the silica film is n ₁ , the refractive index of air is n ₀ , and the voids of the silica film When the rate is X (%), the following equation (i) holds, and therefore the porosity X of the silica film can be obtained from the following equation (ii).
_{n 1 × (100-X)} + n 0 × X = n × 100 (i)
X = (100n ₁ -100n) / (n ₁ -n ₀ ) (ii)
For example, since the refractive index n _{1 of} silica = 1.47 and the refractive index of air n ₀ = 1.00,
1.47 × (100−X) + 1.00 × X = n
And
X = (147-100n) /0.47
Is required.

  The porosity of the silica film is preferably 30% or more, particularly 35% or more, in order to lower the refractive index and increase the light extraction efficiency. However, if the porosity is excessively high, the mechanical strength of the silica film is increased. Insufficient, the silica film is easily broken, and the adhesion with the base of the silica film (the sealing material layer or the upper surface of the concave package) is deteriorated, so 55% or less, particularly 50% or less is preferable.

In order to lower the refractive index of the silica film, it is preferable to increase the air content in the silica film. As the method, in addition to the above-described method of increasing the porosity, silica in the silica film (that is, silica film formation) As silica), hollow silica (having cavities inside the particles) may be used partially or entirely.
About a silica particle, a particle diameter and the thickness of the wall of a particle can be measured by TEM observation, and it can confirm that it has a cavity. As a commercial product of hollow silica, JGC Catalysts &Chemicals' hollow silica can be used.

<Mode of air gap>
When the silica film of the present invention is a porous silica film as described above, the mode pore diameter is preferably 0.5 to 10 nm. If the most frequent gap diameter is too large, the mechanical strength of the silica film becomes weak, and the film may fall off during production. If the mode gap diameter is too small, it is difficult to increase the porosity of the silica film, and the refractive index cannot be decreased.

The mode pore diameter of the silica film in the present invention can be determined by measuring a BET nitrogen adsorption isotherm using a sample of the silica film. The BET nitrogen adsorption isotherm can be measured by, for example, AS-1 manufactured by Cantachrome.
The sample of the silica film may be obtained by peeling from the LED device of the present invention, or the coating solution for forming the silica film may be obtained from a substrate such as Teflon, silicone resin or glass under the same conditions as those for forming the silica film of the present invention. It may be obtained by applying to a material and drying.

<Film thickness>
The film thickness of the silica film of the present invention is preferably 60 to 160 nm.
If the thickness of the silica film of the present invention is too thick, the minimum reflectance may shift to the high wavelength side, and light may not be extracted efficiently on the low wavelength side of the visible light region. On the other hand, if the film thickness is too thin, the minimum reflectance may shift to the low wavelength side, and light may not be extracted efficiently on the high wavelength side of the visible light region.
The thickness of the silica film of the present invention is more preferably 80 to 120 nm.

  In addition, the film thickness of a silica film can be analyzed using, for example, an SEM photograph or an ellipsometer, or a stylus type step / surface roughness / fine shape measuring device (manufactured by KLA-Tencor Corporation: P-15). Can be measured at a stylus force (tactile pressure) of 0.2 mg and a scanning speed of 10 μm / second.

<Film forming method>
The method for producing the silica film of the present invention is not particularly limited, but a porous silica film having a porosity suitable for the present invention (hereinafter sometimes referred to as “the porous silica film of the present invention”) is efficiently used. An example of a method capable of forming a film with high productivity will be described in detail below.

(Method for forming porous silica film)
The porous silica film of the present invention is formed by the following steps.
(A) Step of preparing a raw material liquid for forming a porous silica film (b) Step of forming a porous silica film from the raw material liquid (c) Step of drying the porous silica film Hereinafter, each step will be described.

(A) a step of preparing a raw material liquid for forming a porous silica film;
The raw material liquid for forming the porous silica film is a hydrous organic solution mainly containing alkoxysilanes and containing a raw material compound capable of increasing the molecular weight by a hydrolysis reaction and a dehydration condensation reaction.

  The water-containing organic solution that is the raw material liquid for forming the porous silica film of the present invention contains alkoxysilanes, an organic solvent, water, and a catalyst that is added as necessary.

  Examples of alkoxysilanes include tetramethoxysilane, tetraethoxysilane, tetra (n-propoxy) silane, tetraisopropoxysilane, tetra (n-butoxy) silane, and the like, trimethoxysilane, triethoxysilane, and methyl. Trialkoxysilanes such as trimethoxysilane, methyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, dialkoxysilanes such as dimethyldimethoxysilane, dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, bis (Trimethoxysilyl) methane, bis (triethoxysilyl) methane, 1,2-bis (trimethoxysilyl) ethane, 1,2-bis (triethoxysilyl) ethane, 1,4-bis (tri Toxylsilyl) benzene, 1,4-bis (triethoxysilyl) benzene, 1,3,5-tris (trimethoxysilyl) benzene and the like, in which two or more trialkoxysilyl groups are bonded, 3- Aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-acryloyloxypropyltrimethoxysilane, An alkyl group substituted on a silicon atom, such as 3-carboxypropyltrimethoxysilane, has a reactive functional group, and may be a partial hydrolyzate or oligomer.

  Among these, tetramethoxysilane, tetraethoxysilane, trimethoxysilane, triethoxysilane, tetramethoxysilane, or tetraethoxysilane oligomer is particularly preferable. In particular, tetramethoxysilane oligomers are most preferably used because of their reactivity and controllability of gelation.

  Furthermore, monoalkoxysilanes having 2 to 3 hydrogen, alkyl groups, or aryl groups on silicon atoms can be mixed with the alkoxysilanes. By mixing monoalkoxysilanes, the resulting porous silica membrane can be hydrophobized to improve water resistance. Examples of monoalkoxysilanes include triethylmethoxysilane, triethylethoxysilane, tripropylmethoxysilane, triphenylmethoxysilane, triphenylethoxysilane, diphenylmethylmethoxysilane, diphenylmethylethoxysilane, and the like. The mixing amount of monoalkoxysilanes is desirably 70 mol% or less of the total alkoxysilanes. If the mixing amount exceeds 70 mol%, ideal gelation may not occur.

  Further, fluorinated alkyls such as (3,3,3-trifluoropropyl) trimethoxysilane, (3,3,3-trifluoropropyl) triethoxysilane, pentafluorophenyltrimethoxysilane, pentafluorophenyltriethoxysilane When an alkoxysilane having a group or a fluorinated aryl group is used in combination, excellent water resistance, moisture resistance, stain resistance and the like may be obtained.

The shape of the oligomer in the raw material liquid is not particularly limited, and examples thereof include linear, cross-linked, cage-type molecules (silsesquioxane, etc.) and the like. In view of reactivity control at the time of coating, those having linear as the main component are preferable.
In addition, when applying the above-described raw material liquid, it is necessary that a certain degree of high molecular weight (that is, a state in which condensation has progressed to some extent) has already been achieved. It is preferable that high molecular weight is achieved to such an extent that insoluble matter cannot be formed. The reason for this is that if a visible insoluble material exists in the raw material solution before coating, the film structure becomes non-uniform, cracks may occur from the insoluble material, and mechanical strength may be reduced. Because there is.

  As the organic solvent, those having the ability to mix alkoxysilanes constituting the raw material liquid, water and other organic compounds are preferably used. Usable organic solvents include alcohols such as monohydric alcohols having 1 to 4 carbon atoms, dihydric alcohols having 1 to 4 carbon atoms, polyhydric alcohols such as glycerin and pentaerythritol; diethylene glycol, ethylene glycol monomethyl ether, ethylene Glycol dimethyl ether, 2-ethoxyethanol, propylene glycol monomethyl ether, propylene glycol methyl ether acetate and the like, ethers or esterified products of the above alcohols; ketones such as acetone and methyl ethyl ketone; formamide, N-methylformamide, N-ethylformamide, N , N-dimethylformamide, N, N-diethylformamide, N-methylacetamide, N-ethylacetamide, N, N-dimethylacetamide, N, N-die Ruacetamide, N-methylpyrrolidone, N-formylmorpholine, N-acetylmorpholine, N-formylpiperidine, N-acetylpiperidine, N-formylpyrrolidine, N-acetylpyrrolidine, N, N′-diformylpiperazine, N, N Amides such as' -diformylpiperazine and N, N'-diacetylpiperazine; Lactones such as γ-butyrolactone; Ureas such as tetramethylurea and N, N'-dimethylimidazolidine; Dimethylsulfoxide and the like . These organic solvents may be used alone or as a mixture.

  In order to make the porous silica film of the present invention have an appropriate stable structure, an organic solvent having high volatility is preferable, among which methanol, ethanol, n-propanol, isopropyl alcohol, and acetone are more preferable, and methanol or ethanol is most preferable.

  In order to form the porous silica film of the present invention, a high-boiling hydrophilic organic compound may be contained in addition to the organic solvent described above. A high-boiling hydrophilic organic compound is an organic compound having a hydrophilic functional group such as a hydroxyl group, a carbonyl group, an ether bond, an ester bond, a carbonate bond, a carboxyl group, an amide bond, a urethane bond, or a urea bond in the molecular structure. That is. The hydrophilic organic compound may have a plurality of these hydrophilic functional groups in the molecular structure. The boiling point here is a boiling point under a pressure of 760 mmHg. The boiling point is preferably 80 ° C. or higher, and when a hydrophilic organic compound having a boiling point of less than 80 ° C. is used, the porosity of the porous silica film may be extremely reduced. Preferable examples of the hydrophilic organic compound having a boiling point of 80 ° C. or higher include alcohols having 3 to 8 carbon atoms, polyhydric alcohols having 2 to 6 carbon atoms, and phenols. More preferred hydrophilic organic compounds include alcohols having 3 to 8 carbon atoms, diols having 2 to 8 carbon atoms, triols having 3 to 8 carbon atoms, and tetraols having 4 to 8 carbon atoms. More preferable hydrophilic organic compounds include alcohols having 4 to 7 carbon atoms such as n-butanol, isobutyl alcohol, t-butyl alcohol, n-pentanol, cyclopentanol, n-hexanol, cyclohexanol, benzyl alcohol, C2-C4 diols such as ethylene glycol, propylene glycol, 1,4-butanediol, C3-C6 triols such as glycerol and trishydroxymethylethane, C4 such as erythritol and pentaerythritol -5 tetraols. In this hydrophilic organic compound, if there are too many carbon atoms, the hydrophilicity may be lowered too much, and the dispersibility of the alkoxysilanes before the hydrolysis reaction may be destabilized.

  A catalyst is mix | blended as needed. Examples of the catalyst include substances that promote the hydrolysis and dehydration condensation reactions of the alkoxysilanes described above. Specific examples include acids such as hydrochloric acid, nitric acid, sulfuric acid, formic acid, acetic acid, oxalic acid and maleic acid; amines such as ammonia, butylamine, dibutylamine and triethylamine; bases such as pyridine; Lewis such as acetylacetone complex of aluminum Acids; and the like.

  Examples of the metal species of the metal chelate compound used as the catalyst include titanium, aluminum, zirconium, tin, and antimony. Specific examples of the metal chelate compound include the following.

  Examples of aluminum complexes include di-ethoxy mono (acetylacetonato) aluminum, di-n-propoxy mono (acetylacetonato) aluminum, di-isopropoxy mono (acetylacetonato) aluminum, di-n-butoxy. Mono (acetylacetonato) aluminum, di-sec-butoxy mono (acetylacetonato) aluminum, di-tert-butoxy mono (acetylacetonato) aluminum, monoethoxy bis (acetylacetonato) aluminum, mono-n -Propoxy bis (acetylacetonato) aluminum, monoisopropoxy bis (acetylacetonato) aluminum, mono-n-butoxy bis (acetylacetonato) aluminum, mono-sec-butoxy bi (Acetylacetonato) aluminum, mono-tert-butoxy bis (acetylacetonato) aluminum, tris (acetylacetonato) aluminum, diethoxy mono (ethylacetoacetate) aluminum, di-n-propoxy mono (ethylacetoacetate) ) Aluminum, diisopropoxy mono (ethyl acetoacetate) aluminum, di-n-butoxy mono (ethyl acetoacetate) aluminum, di-sec-butoxy mono (ethyl acetoacetate) aluminum, di-tert-butoxy mono (Ethyl acetoacetate) aluminum, monoethoxy bis (ethyl acetoacetate) aluminum, mono-n-propoxy bis (ethyl acetoacetate) aluminum, monoisoprop Xy-bis (ethyl acetoacetate) aluminum, mono-n-butoxy bis (ethyl acetoacetate) aluminum, mono-sec-butoxy bis (ethyl acetoacetate) aluminum, mono-tert-butoxy bis (ethyl acetoacetate) Examples thereof include aluminum chelate compounds such as aluminum and tris (ethylacetoacetate) aluminum.

  Titanium complexes include triethoxy mono (acetylacetonato) titanium, tri-n-propoxy mono (acetylacetonato) titanium, triisopropoxy mono (acetylacetonato) titanium, tri-n-butoxy mono (acetyl). Acetonato) titanium, tri-sec-butoxy mono (acetylacetonato) titanium, tri-tert-butoxy mono (acetylacetonato) titanium, diethoxy bis (acetylacetonato) titanium, di-n-propoxy bis (Acetylacetonato) titanium, diisopropoxy bis (acetylacetonato) titanium, di-n-butoxy bis (acetylacetonato) titanium, di-sec-butoxy bis (acetylacetonato) titanium, di-tert -Butoxy bis (ace Ruacetonate) titanium, monoethoxy tris (acetylacetonato) titanium, mono-n-propoxy tris (acetylacetonato) titanium, monoisopropoxy tris (acetylacetonato) titanium, mono-n-butoxy tris (acetyl) Acetonato) titanium, mono-sec-butoxy-tris (acetylacetonato) titanium, mono-tert-butoxy-tris (acetylacetonato) titanium, tetrakis (acetylacetonato) titanium, triethoxy mono (ethylacetoacetate) titanium , Tri-n-propoxy mono (ethyl acetoacetate) titanium, triisopropoxy mono (ethyl acetoacetate) titanium, tri-n-butoxy mono (ethyl acetoacetate) titanium, tri-sec-butyl Xy mono (ethyl acetoacetate) titanium, tri-tert-butoxy mono (ethyl acetoacetate) titanium, diethoxy bis (ethyl acetoacetate) titanium, di-n-propoxy bis (ethyl acetoacetate) titanium, diiso Propoxy bis (ethyl acetoacetate) titanium, di-n-butoxy bis (ethyl acetoacetate) titanium, di-sec-butoxy bis (ethyl acetoacetate) titanium, di-tert-butoxy bis (ethyl acetoacetate) Titanium, monoethoxy tris (ethyl acetoacetate) titanium, mono-n-propoxy tris (ethyl acetoacetate) titanium, monoisopropoxy tris (ethyl acetoacetate) titanium, mono-n-butoxy tris (ethyl acetoacetate) Acetate) titanium, mono-sec-butoxy tris (ethyl acetoacetate) titanium, mono-tert-butoxy tris (ethyl acetoacetate) titanium, tetrakis (ethyl acetoacetate) titanium, mono (acetylacetonate) tris (ethyl aceto) Acetate) titanium, bis (acetylacetonato) bis (ethylacetoacetate) titanium, tris (acetylacetonato) mono (ethylacetoacetate) titanium and the like.

  In addition to these catalysts, weak alkaline compounds such as basic catalysts such as ammonia may be used. In this case, it is preferable to appropriately adjust the silica concentration, the organic solvent species, and the like. Moreover, when preparing a water-containing organic solution, it is preferable not to increase the catalyst concentration in a solution rapidly. As a specific example, there is a method of mixing alkoxysilanes and a part of an organic solvent, then mixing water, and finally mixing the remaining organic solvent and base.

  The addition amount of the catalyst is preferably adjusted according to the reaction rate of the raw material. The hydrolysis reaction and the dehydration condensation reaction may proceed simultaneously. In that case, the pH is preferably adjusted to 3 to 7, more preferably adjusted to 4 to 6. Alternatively, the hydrolysis reaction may proceed preferentially under acidic conditions, and the dehydration condensation reaction may proceed preferentially under alkaline conditions. The hydrolysis reaction is preferably adjusted to pH 8 or lower, more preferably adjusted to pH 5 or lower. The dehydration condensation reaction is preferably adjusted to have a pH of 6 or more, and more preferably adjusted to have a pH of 9 or more.

The raw material liquid for forming the porous silica film of the present invention is formed by blending the above-mentioned raw materials.
The blending ratio of the alkoxysilanes is preferably 1 to 60% by weight and more preferably 5 to 40% by weight with respect to the whole raw material liquid. When the blending ratio of alkoxysilanes exceeds 60% by weight, it is difficult to maintain the stability of the raw material liquid, and the porous silica film may be broken during film formation. On the other hand, when the compounding ratio of alkoxysilanes is less than 1% by weight, the hydrolysis reaction and dehydration condensation reaction may be extremely slow, or the film formability may be deteriorated (film unevenness).

  Water is necessary for the hydrolysis of alkoxysilanes, and is important from the viewpoint of the stability of the coating solution and the film forming property of the porous silica film. Therefore, when the amount of water required for hydrolysis is defined by a molar ratio with respect to the amount of alkoxy groups, it is 0.1 to 1.6 mol times the amount of 1 mol of alkoxy groups in the alkoxysilane, particularly 0.3 to 1 .2 mole times, particularly 0.5 to 0.7 mole times is preferred. The amount of water in the coating solution is not limited to this, and in order to adjust the stability of the coating solution and the film forming property, it is added in an upper limit of 50 mol times, preferably 40 mol times after the hydrolysis reaction. Also good.

  Water may be added at any time after the alkoxysilanes are dissolved in an organic solvent. Desirably, the alkoxysilanes, catalyst and other additives are sufficiently dispersed in the solvent, and then water is added. The hydrolysis reaction is caused by adding water, but the water can be added as an aqueous alcohol solution or as water vapor without being particularly limited. In addition, if water is added rapidly, depending on the type of alkoxysilane, the hydrolysis reaction and the dehydration condensation reaction occur too quickly, and precipitation may occur. Therefore, in order to prevent such precipitation, take sufficient time to add water, make the alcohol solvent coexist in a state where water is added uniformly, and add water at a low temperature. It is preferable to use means such as suppressing the reaction alone or in combination.

  What is necessary is just to use the purity of the water to be used which processed either or both of ion exchange and distillation. When a porous silica membrane with higher purity is required, it is desirable to use ultrapure water obtained by further ion-exchanged distilled water. In this case, for example, a filter having a pore size of 0.01 to 0.5 μm Water that has been passed through may be used.

  When a hydrophilic organic compound having a boiling point of 80 ° C. or higher is used in the water-containing organic solution, the content of the hydrophilic organic compound having a boiling point of 80 ° C. or higher is equal to the total content of the organic solvent and the hydrophilic organic compound having a boiling point of 80 ° C. or higher. On the other hand, it is important that the amount is not more than a specific amount. The content of the hydrophilic organic compound having a boiling point of 80 ° C. or higher with respect to the total content is 90% by weight or less, preferably 85% by weight or less.

  If the blending ratio of the hydrophilic organic compound having a boiling point of 80 ° C. or higher is too small, the film structure may be fixed immediately after coating. On the other hand, if the blending ratio of the hydrophilic organic compound having a boiling point of 80 ° C. or higher is too large, the film immediately after coating does not have a stable structure, and process restrictions such as temperature and time during drying occur, which may affect production efficiency. There is.

The atmospheric temperature in the preparation of the raw material liquid and the mixing order are arbitrary, but in order to obtain a uniform structure formation in the raw material liquid, water is preferably mixed last. Further, in order to suppress extreme hydrolysis and dehydration condensation reaction of alkoxysilanes in the raw material liquid, the raw material liquid is usually adjusted at 0 to 60 ° C., particularly 15 to 40 ° C., particularly 15 to 30 ° C. It is preferable to carry out under wet conditions.
At the time of liquid preparation, the stirring operation of the raw material liquid is arbitrary, but it is more preferable to stir with a stirrer for each mixing.

  Furthermore, after the raw material solution is adjusted, the solution is preferably aged in order to proceed with hydrolysis and dehydration condensation reaction of alkoxysilanes. During this ripening period, it is preferable that the hydrolyzed condensate of the alkoxysilanes to be produced is in a state of being more uniformly dispersed in the raw material liquid, so that the liquid is preferably stirred.

  The temperature during the aging period is arbitrary, and in general, it may be heated at room temperature or continuously or intermittently. Among these, heat aging is preferable in order to form a uniform three-dimensional network structure by the hydrolysis condensate of alkoxysilanes. The specific temperature is not particularly limited as long as it is equal to or lower than the boiling point of the organic solvent to be used, and heat aging can be performed at a temperature equal to or higher than the boiling point of the organic solvent used under pressure. The heat aging time is appropriately adjusted depending on the temperature to be applied, but is preferably 15 hours or less, and more preferably 5 hours or less.

(B) forming a porous silica film from the raw material liquid;
The porous silica film is formed by directly applying the raw material liquid prepared above onto the surface of the encapsulated package.
The raw material liquid may be used as it is, or may be diluted with the organic solvent used for preparing the raw material liquid depending on the coating method. In the case of dilution, the raw material solution is usually diluted 5 times or less, preferably 2 times or less.

  Examples of the direct application method of the raw material liquid onto the encapsulated package surface include a general coater such as spin coating and spray coating, and a method of applying with a stamp. Among these, since it can prevent that the raw material liquid apply | coated to a lead wire etc. adheres especially, application | coating by a stamp is preferable.

  The atmosphere during coating may be air or an inert gas such as nitrogen or argon, and the temperature is usually 0 to 60 ° C., preferably 10 to 50 ° C., more preferably 20 to 40 ° C. The humidity is usually 5 to 90%, preferably 10 to 80%, more preferably 15 to 70%.

(C) a step of drying the porous silica membrane;
The drying step is performed for the purpose of removing volatile components remaining in the porous silica membrane and / or for the purpose of maximizing the hydrolysis condensation reaction of alkoxysilanes. The drying temperature is 20 to 200 ° C., preferably 30 to 120 ° C., more preferably 50 to 100 ° C., and the drying time is 1 minute to 50 hours, preferably 3 minutes to 30 hours, more preferably 5 minutes to 15 hours.

  The drying method can be performed by a known method such as blow drying or drying under reduced pressure, and may be combined. After the blast drying, vacuum drying for the purpose of sufficiently removing volatile components can be added.

  As described above, the porous silica film of the present invention is formed by directly applying the raw material liquid to the encapsulated package to form a film, or by applying the raw material liquid to a PET film or the like, heat-treating it, and drying it. It is also possible to form the film by transferring the film formed thereon onto an encapsulated package.

<Other processing>
In the silica film of the present invention, silicone may be added to the composition in order to increase the adhesion with the sealing material. Therefore, a silica film may be formed by blending silicone with the above raw material liquid. As the silicone, a modified silicone oil is particularly preferable, and a modified silicone oil into which an organic group of a side chain type, a both terminal type, a single terminal type, or a side chain both terminal type is introduced is preferable. Here, as the organic group, amino-modified, epoxy-modified, carbinol-modified, methacryl-modified, polyether-modified, mercapto-modified, carboxyl-modified, phenol-modified, silanol-modified, diol-modified, methacryl-modified, alkoxy-modified may be used. it can.
The amount of silicone added is preferably 0.5 to 5% by weight in the silica film (solid content).

  Further, by treating the porous silica film formed as described above with a silylating agent, the surface can be made more excellent in functionality. That is, by treating with a silylating agent, hydrophobicity is imparted to the porous silica film, and the pores can be prevented from being contaminated by impurities such as alkaline water. Examples of the silylating agent include trimethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethylethoxysilane, methyldiethoxysilane, dimethylvinylmethoxysilane, and dimethyl. Alkoxysilanes such as vinylethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, methyldichlorosilane, dimethylchlorosolane, dimethylvinylchlorosilane , Methyl vinyl dichlorosilane, methyl chloro disilane, triphenyl chloro silane, methyl diphenyl chloro Chlorosilanes such as silane, diphenyldichlorosilane, hexamethyldisilazane, N, N′-bis (trimethylsilyl) urea, N-trimethylsilylacetamide, dimethyltrimethylsilylamine, diethyltriethylsilylamine, trimethylsilylimidazole and other silazanes, (3, 3,3-trifluoropropyl) trimethoxysilane, (3,3,3-trifluoropropyl) triethoxysilane, pentafluorophenyltrimethoxysilane, pentafluorophenyltriethoxysilane, etc. And alkoxysilanes having a group. Silylation can be carried out by applying a silylating agent to the porous silica film or exposing the porous silica film to the vapor of the silylating agent.

[Concave package]
A package refers to a member on which a light emitting element is stacked in an LED device, and the package according to the present invention is a concave package provided with a LED element and a recess for filling a phosphor and a sealing material.

  As a constituent material of the concave package, an organic material, an inorganic material, etc. are usually mentioned.

  Organic materials include polycarbonate resins, polyphenylene sulfide resins, epoxy resins, acrylic resins, silicone resins, ABS resins, nylon resins, polyphthalamide resins, polyethylene resins, and the like, and these resins and glass fillers. Examples thereof include reinforced plastics in which inorganic powder is mixed, heat resistance and mechanical strength are improved, and a coefficient of thermal expansion is reduced.

Inorganic materials include glass materials, ceramic materials such as SiN _x , SiC _x , SiO _x , AlN, and Al ₂ O ₃ ; metals such as iron, copper, brass, aluminum, nickel, gold, silver, platinum, and palladium Materials or alloys thereof may be mentioned.

  For power devices that generate a large amount of heat and emit light, an inorganic material that is superior in heat resistance and light resistance is more suitable than an organic material that easily undergoes deterioration such as discoloration.

The shape of the package is not particularly limited as long as it is a concave shape, and a known package can be used. As specific shapes, the cup portion and the substrate portion are integrated as shown in FIG. 1, they are separate as shown in FIG. 2, copper or aluminum is directly under the LED element, etc. There may be mentioned those provided with a heat sink composed of the above, and those in which the reflecting surface (inner wall surface) of the recess is coated with a reflecting film such as silver.
In the cup / substrate separate type as shown in FIG. 2, the constituent material of the cup and the constituent material of the substrate may be the same or different.

[LED element]
Specific examples of the LED element used in the present invention include a GaN-based compound semiconductor, a ZnSe-based compound semiconductor, and a ZnO-based compound semiconductor. Among these, it is preferable to use a GaN compound semiconductor. This is because GaN-based compound semiconductors have significantly higher light output and external quantum efficiency than SiC _x- based compound semiconductors that emit light in this region, and when combined with phosphors, emit very bright light with very low power. It is because it is obtained. For example, for the same current load, a GaN-based device usually has a light emission intensity 100 times or more that of a SiC _x- based device. Among GaN-based devices, those having an In _x Ga _y N light-emitting layer are particularly preferable because the light emission intensity is very high.
In the above, the value of x + y is usually in the range of 0.8 to 1.2. In the GaN-based device, those in which the light emitting layer is doped with Zn or Si or those without a dopant are preferable for adjusting the light emission characteristics.

[Phosphor]
The phosphor is not particularly limited as long as it is a substance that is directly or indirectly excited by the light emitted from the LED element and emits light of a different wavelength. Even if it is an inorganic phosphor, it is an organic phosphor. Even if it exists, it can be used. For example, one or more of blue phosphor, green phosphor, yellow phosphor, orange to red phosphor as exemplified below can be used. It is preferable to appropriately adjust the type and content of the phosphor used so that a desired emission color can be obtained.

<Blue phosphor>
As the blue phosphor, those having an emission peak wavelength of usually 420 nm or more, particularly 430 nm or more, more preferably 440 nm or more, and usually 490 nm or less, especially 480 nm or less, and further 470 nm or less are preferable.
Specifically, (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu, (Ba, Ca, Mg, Sr) ₂ SiO ₄ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu, (Ba, Ca, Sr) ₃ MgSi ₂ O ₈ : Eu are preferred, Ba, Sr) MgAl ₁₀ O ₁₇ : Eu, (Ca, Sr, Ba) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu, and Ba ₃ MgSi ₂ O ₈ : Eu are more preferable.

<Green phosphor>
The green phosphor preferably has an emission peak wavelength in the range of usually 500 nm or more, particularly 510 nm or more, more preferably 515 nm or more, and usually 550 nm or less, especially 542 nm or less, and even 535 nm or less.
_{Specifically, Y 3 (Al, Ga)} 5 O 12: Ce, CaSc 2 O 4: Ce, Ca 3 (Sc, Mg) 2 Si 3 O 12: Ce, (Sr, Ba) 2 SiO 4: Eu Β-sialon, (Ba, Sr) ₃ Si ₆ O ₁₂ : N ₂ : Eu, SrGa ₂ S ₄ : Eu, and BaMgAl ₁₀ O ₁₇ : Eu, Mn are preferable.

<Yellow phosphor>
As the yellow phosphor, those having an emission peak wavelength of usually 530 nm or more, particularly 540 nm or more, more preferably 550 nm or more, and usually 620 nm or less, especially 600 nm or less, further 580 nm or less are suitable.
The yellow _{phosphor, Y 3 Al 5 O 12:} Ce, (Y, Gd) 3 Al 5 O 12: Ce, (Sr, Ca, Ba, Mg) 2 SiO 4: Eu, (Ca, Sr) Si 2 N ₂ O ₂ : Eu, (La, Y, Gd, Lu) ₃ (Si, Ge) ₆ N ₁₁ : Ce are preferable.

<Orange to red phosphor>
As the orange to red phosphor, those having an emission peak wavelength in the range of usually 570 nm or more, particularly 580 nm or more, more preferably 585 nm or more, and usually 780 nm or less, particularly 700 nm or less, further 680 nm or less are preferable.
Specifically, (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Ca, Sr, Ba) Si (N, O) ₂ : Eu, (Ca, Sr, Ba) AlSi ( _{N, O) 3: Eu,} (Sr, Ba) 3 SiO 5: Eu, (Ca, Sr) S: Eu, (La, Y) 2 O 2 S: Eu, Eu ( _{dibenzoylmethane)} 3 · 1, Β-diketone Eu complex such as 10-phenanthroline complex, carboxylic acid Eu complex, K ₂ SiF ₆ : Mn is preferable, (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Sr, Ca) AlSi (N, O): Eu, (La, Y) ₂ O ₂ S: Eu, and K ₂ SiF ₆ : Mn are more preferable.
As the orange phosphor, (Sr, Ba) ₃ SiO ₅ : Eu, (Sr, Ba) ₂ SiO ₄ : Eu, (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, ( Ca, Sr, Ba) AlSi (N, O) ₃ : Ce is preferred.

[Encapsulant]
The sealing material is used for sealing the LED element in the concave portion of the concave package, and may be any transparent material that satisfies the conditions such as heat resistance, light resistance, and durability required for the LED device, and is not particularly limited. However, in the present invention, the sealing material is filled in the concave portion of the concave package in which the LED element is previously disposed and the conductive wire is attached as the phosphor-containing composition in which the phosphor is dispersed as described above. Therefore, the phosphor does not impair the performance of the phosphor within the intended range, and exhibits a liquid property under the desired use conditions, suitably disperses the phosphor, and performs an undesirable reaction. Any inorganic and / or organic material can be used within the range of materials that do not occur.

  As the inorganic material as the sealing material, for example, a solution obtained by hydrolyzing a solution containing a metal alkoxide, a ceramic precursor polymer or a metal alkoxide by a sol-gel method, or a combination thereof is solidified. Examples thereof include materials (for example, inorganic materials having a siloxane bond).

  Examples of organic materials include thermoplastic resins, thermosetting resins, and photocurable resins. Specifically, for example, methacrylic resin such as polymethylmethacrylate; styrene resin such as polystyrene and styrene-acrylonitrile copolymer; polycarbonate resin; polyester resin; phenoxy resin; butyral resin; polyvinyl alcohol; Cellulose resins such as cellulose acetate butyrate; epoxy resins; phenol resins; silicone resins.

  Among these, in particular, when applied to high-power LED devices such as lighting, it is preferable to use a silicon-containing compound for the purpose of ensuring heat resistance and light resistance.

  The silicon-containing compound refers to a compound having a silicon atom in the molecule, for example, an organic material (silicone material) such as polyorganosiloxane, an inorganic material such as silicon oxide, silicon nitride, silicon oxynitride, and borosilicate, Examples thereof include glass materials such as phosphosilicate and alkali silicate. Among these, silicone materials are preferable from the viewpoint of ease of handling.

The silicone material generally refers to an organic polymer having a siloxane bond as a main chain, and examples thereof include a compound represented by the following general formula (i) and / or a mixture thereof.
(R ¹ R ² R ³ SiO _1/2 ) _M (R ⁴ R ⁵ SiO _2/2 ) _D
(R ⁶ SiO _3/2 ) _T (SiO _4/2 ) _Q (i)

In general formula (i), R < ¹ > -R < ⁶ > represents what is selected from the group which consists of an organic functional group, a hydroxyl group, and a hydrogen atom each independently. R ^{1 to} R ⁶ may be the same or different.
In the general formula (i), M, D, T, and Q are each a number that is 0 or more and less than 1, and satisfies M + D + T + Q = 1.

  A liquid material is used as the silicone material, and a phosphor-containing composition is prepared by dispersing the above-mentioned phosphor in the liquid silicone material, and the phosphor-containing composition is filled in the concave portion of the concave package. Can be used after being cured by heat or light.

  When silicone materials are classified according to the mechanism of curing, silicone materials such as an addition polymerization curing type, a condensation polymerization curing type, an ultraviolet curing type, and a peroxide vulcanization type can be generally cited. Among these, addition polymerization curing type (addition type silicone resin), condensation curing type (condensation type silicone resin), and ultraviolet curing type are preferable. Hereinafter, the addition type silicone material and the condensation type silicone material will be described.

  The addition-type silicone material refers to a material in which a polyorganosiloxane chain is crosslinked by an organic addition bond. A typical example is a compound having a Si—C—C—Si bond at a crosslinking point obtained by reacting vinylsilane and hydrosilane in the presence of an addition catalyst such as a Pt catalyst. As these, commercially available products can be used. Specific examples of addition polymerization curing type trade names include “LPS-1400”, “LPS-2410”, and “LPS-3400” manufactured by Shin-Etsu Chemical Co., Ltd.

On the other hand, examples of the condensation type silicone material include a compound having a Si—O—Si bond obtained by hydrolysis and polycondensation of an alkylalkoxysilane at a crosslinking point.
Specific examples include polycondensates obtained by hydrolysis and polycondensation of compounds represented by the following general formula (ii) and / or (iii) and / or oligomers thereof. In addition, only 1 type may be used for these compounds and / or its oligomer, and 2 or more types may be used together by arbitrary combinations and a ratio.

^{_{G m + X n Y 1 m}} -n ... (ii)
(In General Formula (ii), G represents at least one element selected from silicon, aluminum, zirconium, and titanium, X represents a hydrolyzable group, and Y ¹ represents a monovalent organic group. M represents one or more integers representing the valence of G, and n represents one or more integers representing the number of X groups, provided that m ≧ n.

^{_{(G s + X t Y 1}} s-t) u Y 2 ... (iii)
(In General Formula (iii), G represents at least one element selected from silicon, aluminum, zirconium, and titanium, X represents a hydrolyzable group, and Y ¹ represents a monovalent organic group. Y ² represents a u-valent organic group, s represents an integer of 1 or more representing the valence of G, t represents an integer of 1 or more and s−1 or less, and u represents 2 (It represents the integer above.)

  Further, the condensation type silicone material may contain a curing catalyst. As this curing catalyst, for example, a metal chelate compound or the like can be suitably used. The metal chelate compound preferably contains one or more of Ti, Ta, and Zr, and more preferably contains Zr. In addition, only 1 type may be used for a curing catalyst and it may use 2 or more types together by arbitrary combinations and a ratio.

  Examples of such condensation-type silicone materials include Japanese Patent Application Nos. 2006-47274 to 47277 (for example, Japanese Patent Application Laid-Open Nos. 2007-119297 to 112975 and Japanese Patent Application No. 2007-19459) and Japanese Patent Application No. 2006-176468. The member for semiconductor light-emitting devices described in the specification is suitable.

  The phosphor and the content of the encapsulant in the phosphor-containing composition obtained by dispersing the aforementioned phosphor in an inorganic material and / or an organic material such as a silicone material as the encapsulant described above are: Although it is optional as long as the effects of the present invention are not significantly impaired, the sealing material is usually 50% by weight or more, preferably 75% by weight or more, and usually 99% by weight or less, based on the entire phosphor-containing composition. Preferably, it is 95 weight% or less. Further, the phosphor is usually 1% by weight or more, preferably 5% by weight or more, and usually 50% by weight or less, preferably 25% by weight or less based on the entire phosphor-containing composition. When the amount of the sealing material is large, no particular problem occurs. However, in order to obtain the desired chromaticity coordinates, color rendering index, luminous efficiency, etc. as an LED device, the sealing material is usually used at the blending ratio as described above. It is desirable to use a phosphor. On the other hand, when there are too few sealing materials, there exists a possibility that it may become difficult to handle because there is no fluidity.

  The sealing material mainly has a role as a binder in the phosphor-containing composition. The sealing material may be used alone or in combination of two or more in any combination and ratio. For example, when a silicon-containing compound is used for the purpose of heat resistance, light resistance, etc., other thermosetting resins such as an epoxy resin may be contained to the extent that the durability of the silicon-containing compound is not impaired. In this case, the content of the other thermosetting resin is usually 25% by weight or less, preferably 10% by weight or less based on the total amount of the sealing material as the binder.

  The phosphor-containing composition may contain other components in addition to the phosphor and the sealing material as long as the effects of the present invention are not significantly impaired. Examples of other components include color correction dyes, antioxidants, processing / oxidation and heat stabilizers such as phosphorus-based processing stabilizers, light-resistant stabilizers such as ultraviolet absorbers, and silane coupling agents. These may be used alone or in combination of two or more in any combination and ratio.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

[Example 1]
<Preparation of LED device with porous silica film formation>
0.85 g of methyltrimethoxysilane, 0.15 g of dimethyldimethoxysilane, and 1.00 g of a tetramethoxysilane condensate (methyl silicate heptamer) were stirred at room temperature in 2.00 g of ethanol. To this solution, 0.30 g of 0.1 mol / L hydrochloric acid and 1.00 g of water were added and stirred at room temperature under acidity (pH 2) for hydrolysis. Stirring in ethanol to stirring under acidic conditions was performed for a total of 30 minutes. Then, it was made to age | cure | ripen by stirring for 30 minutes in a 60 degreeC thermostat. Further, with stirring at room temperature, ethanol (3.00 g), water (15.00 g), 0.25 mol / L aqueous sodium hydroxide solution (4.00 g), and ethanol (7.00 g) were added in this order. And dehydrated. Then, it aged by stirring for 60 minutes in a 60 degreeC thermostat, and obtained the raw material liquid for porous silica film formation.
In order to obtain the target film, this raw material solution was diluted 2 times with ethanol to obtain a silica coating solution.

  2 μL of the silica coating solution was placed on the surface of an LED device (Osram Power TOPLED device) as an encapsulated package, and applied with a spin coater (1000 rpm, 30 seconds). Thereafter, heat treatment was performed at 120 ° C. for 10 minutes to form a porous silica film having a thickness of 100 nm.

<Preparation of porous silica film / glass substrate sample>
Using the above silica coating solution, a porous silica film having a film thickness of 100 nm is formed on a glass substrate by applying a heat treatment after applying with a spin coater under the same conditions as those for producing the porous silica film forming LED device. A film was formed.

<Measurement of the most frequent pore diameter of porous silica membrane>
A 10 cm × 20 cm Bencot (manufactured by Asahi Kasei Fibers Co., Ltd.) is folded in a Teflon petri dish. 10 g of the above silica coating solution was impregnated on the bencott, vacuum-dried at room temperature for 30 minutes, then heated and dried at 120 ° C. for 30 minutes, and further vacuum-dried at 90 ° C. for 3 hours. The BET nitrogen adsorption isotherm was measured using AS-1 manufactured by Cantachrome Co., Ltd., using 100 mg of the solid content recovered from the petri dish, and the most frequent pore diameter was determined. As a result, the most frequent gap diameter was 4.2 nm.

<Measurement of porosity of porous silica film>
For the above porous silica film / glass substrate sample, the refractive index n of the porous silica film is measured with a spectroscopic ellipsometer (n = 1.28), and the porosity X is calculated from the above formulas (i) and (ii). As a result (n ₀ = 1.00, n ₁ = 1.47), the porosity of the porous silica film was 40%.

<Evaluation of light extraction efficiency>
The total luminous flux of the porous silica film-formed LED device was measured using a spectroscope “USB2000” (integrated wavelength range: 380 to 780 nm, light receiving method: 38.1 mmφ integrating sphere) manufactured by Ocean Optics. When the total luminous flux was measured 15 seconds after the integrating sphere was turned on, it was 1.5343 lm.

[Comparative Example 1]
For the LED package (Osram Power TOPLED package), the total luminous flux was measured using an integrating sphere in the same manner as in Example 1 without forming a porous silica film. When the total luminous flux was measured 15 seconds after the integrating sphere was turned on, it was 1.5238 lm.

  From the above results, it was confirmed that forming the silica film increased the luminous flux and improved the light extraction efficiency.

  In Example 1 above, since the refractive index of the sealing material used in the LED device on which the porous silica film is formed has not been confirmed, the refractive index of the porous silica film and the refractive index of the encapsulating material Although the relationship is not clarified, the refractive index of the sealing material usually used in LED devices is about 1.53, so the refractive index of the porous silica film (n = 1.28) is more sealed. It is considered to be lower than the refractive index of the stopper.

DESCRIPTION OF SYMBOLS 1,9 Concave type package 1a Cup part 1b Substrate part 2 Concave 3 LED element 3A, 3B Electrode 4 Phosphor 5 Sealing material 6 Die bond material 7A, 7B Lead 8A, 8B Conductive wire 9a Cup 9b Substrate 10, 10A LED device 20 Silica membrane

Claims (4)

  A concave package, an LED element housed in a concave portion of the concave package, and an LED device having a phosphor and a sealing material filled in the concave package, wherein the opening of the concave portion of the concave package is silica An LED device that is coated with a film.   The LED device according to claim 1, wherein the silica film is a porous film having a porosity of 25% or more, and a refractive index of the silica film is lower than a refractive index of the sealing material.   The LED device according to claim 2, wherein a mode diameter of the silica film is 0.5 to 10 nm.   The LED device according to claim 1, wherein the silica film has a thickness of 60 to 160 nm.

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