JP2005225964A - Composition for optical semiconductor encapsulation - Google Patents

Abstract

【化２】

【化３】

【化５】

【化６】

【選択図】なしThe present invention provides a sealing composition for an optical semiconductor, in which the obtained cured product is colorless and transparent and has improved UV durability.
[MEANS FOR SOLVING PROBLEMS] (A) An alicyclic epoxy compound, (B) a carboxylic anhydride-based curing agent, (C) a curing accelerator, and (D) inorganic oxide particles having a primary average particle size of 100 nm or less. A composition for sealing an optical semiconductor.
As the component (A), compounds represented by the following formulas (1) to (3) are preferable, and as the component (B), compounds represented by the following formulas (5) to (6) are preferable. As component D), particles of silica, alumina, zirconia, antimony oxide and the like are preferable.
[Chemical 1]

[Chemical 2]

[Chemical 3]

[Chemical formula 5]

[Chemical 6]

[Selection figure] None

Description

  The present invention relates to a composition for sealing an optical semiconductor such as a blue LED or a white LED.

As an optical semiconductor sealing material, conventionally, an epoxy compound mainly composed of bisphenol A glycidyl ether has been used. However, since such an epoxy compound has an aromatic ring, durability (UV durability) against ultraviolet rays (UV) is insufficient to seal an optical semiconductor that emits blue light or ultraviolet light. .
Therefore, in order to improve the UV durability of the optical semiconductor sealing material, it has been proposed to use an alicyclic epoxy compound (see, for example, Patent Document 1), but the UV durability is still not sufficient. It was.

JP 2003-82062 A

  This invention is made | formed in view of the said situation, The subject is providing the composition for optical semiconductor sealing by which the hardened | cured material obtained was colorless and transparent and UV durability was improved.

The present invention
It comprises (A) an alicyclic epoxy compound, (B) a carboxylic anhydride-based curing agent, (C) a curing accelerator, and (D) inorganic oxide particles having a primary average particle size of 100 nm or less. Composition for optical semiconductor encapsulation,
Consists of.

Hereinafter, the present invention will be described in detail.
(A) Alicyclic epoxy compound Although it does not specifically limit as an alicyclic epoxy compound used by this invention, For example,
Compounds represented by the following formulas (1) to (4)

[In the formula (4), R represents a linear or branched alkyl group having 1 to 20 carbon atoms or a saturated or unsaturated monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms. The alkyl group and the monovalent alicyclic hydrocarbon group may be substituted, n is an integer of 1 to 30, and f is an integer of 1 to 6. ]
Or

Epoxycyclopentane, epoxycyclohexane, α-pinene oxide, norbornene oxide, cyclopentyl glycidyl ether, cyclohexyl glycidyl ether, cyclopentane methanol glycidyl ether, cyclohexane methanol glycidyl ether,
Cyclopentanecarboxylic acid glycidyl ester, tetrahydrobenzoic acid glycidyl ester, hexahydrobenzoic acid glycidyl ester, tetrahydrobenzoic acid 3,4-epoxycyclopentyl ester, tetrahydrobenzoic acid 3,4-epoxycyclohexyl ester, hexahydrobenzoic acid 3,4-epoxycyclopentyl Other alicyclic monoepoxy compounds such as esters, hexahydrobenzoic acid 3,4-epoxycyclohexyl ester;

1,2-cyclopentanedimethanol diglycidyl ether, 1,3-cyclopentanedimethanol diglycidyl ether, 1,2-cyclohexanedimethanol diglycidyl ether, 1,3-cyclohexanedimethanol diglycidyl ether, 1,4- Cyclohexane dimethanol diglycidyl ether,
1,2-cyclopentanedicarboxylic acid diglycidyl ester, 1,3-cyclopentanedicarboxylic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, tetrahydroisophthalic acid diglycidyl ester, tetrahydroterephthalic acid diglycidyl ester, hexahydrophthalic acid diester Glycidyl ester, hexahydroisophthalic acid diglycidyl ester, hexahydroterephthalic acid diglycidyl ester,

Tetrahydrophthalic acid di (3,4-epoxycyclopentyl ester), tetrahydrophthalic acid di (3,4-epoxycyclohexyl ester), tetrahydroisophthalic acid di (3,4-epoxycyclopentyl ester), tetrahydroisophthalic acid di (3,4 -Epoxycyclohexyl ester), tetrahydroterephthalic acid di (3,4-epoxycyclopentyl ester), tetrahydroterephthalic acid di (3,4-epoxycyclohexyl ester),
Hexahydrophthalic acid di (3,4-epoxycyclopentyl ester), hexahydrophthalic acid di (3,4-epoxycyclohexyl ester), hexahydroisophthalic acid di (3,4-epoxycyclopentyl ester), hexahydroisophthalic acid di (3,4-epoxycyclohexyl ester), hexahydroterephthalic acid di (3,4-epoxycyclopentyl ester), hexahydroterephthalic acid di (3,4-epoxycyclohexyl ester)
And other alicyclic polyepoxy compounds.

Of these alicyclic epoxy compounds, alicyclic polyepoxy compounds are preferred, and in particular, the compounds represented by the formulas (1) to (3) are the fluidity of the composition and the heat resistance of the resulting cured product. From the point of view, it is preferable.
The said alicyclic epoxy compound can be used individually or in mixture of 2 or more types.

In the present invention, one or more aliphatic epoxy compounds and aromatic epoxy compounds may be used in combination as long as the desired effects of the present invention are not impaired.
Examples of the aliphatic epoxy compound include:
Methyl glycidyl ether, ethyl glycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, glycerin triglycidyl ether,
Examples thereof include glycidyl acetate, glycidyl propionate, succinic acid diglycidyl ester, malonic acid diglycidyl ester, 1,2,3-propanetricarboxylic acid triglycidyl ester, and the like.

Examples of the aromatic epoxy compound include:
Benzoic acid glycidyl ester, benzoic acid 3,4-epoxycyclopentyl ester, benzoic acid 3,4-epoxycyclohexyl ester, phthalic acid diglycidyl ester, phthalic acid di (3,4-epoxycyclopentyl ester), phthalic acid di (3,3 4-epoxycyclohexyl ester), isophthalic acid diglycidyl ester, isophthalic acid di (3,4-epoxycyclopentyl ester), isophthalic acid di (3,4-epoxycyclohexyl ester), terephthalic acid diglycidyl ester, terephthalic acid di (3 , 4-epoxycyclopentyl ester), terephthalic acid di (3,4-epoxycyclohexyl ester) and the like.
The total use ratio of the aliphatic epoxy compound and the aromatic epoxy compound is usually 50% by weight or less, preferably 30% by weight or less based on the total amount with the alicyclic epoxy compound.

(B) Carboxylic anhydride-based curing agent The carboxylic anhydride-based curing agent used in the present invention is a component that causes a curing reaction with (A) an alicyclic epoxy compound.
Although it does not specifically limit as such a carboxylic acid anhydride type hardening | curing agent, For example, the compound represented by following formula (5)-Formula (8)

In addition to methyl nadic anhydride, dodecenyl succinic anhydride, Diels-Alder reaction products of alicyclic compounds having conjugated double bonds such as α-terpinene and alloocimene and maleic anhydride, and hydrogenated products thereof. The alicyclic carboxylic anhydride-based curing agent is preferable. In addition, arbitrary structural isomers and arbitrary geometrical isomers can be used as the Diels-Alder reaction product and hydrogenated products thereof.
Moreover, the said alicyclic carboxylic anhydride type hardening | curing agent can also be chemically modified | denatured and used suitably, unless a hardening reaction is prevented substantially.

Of these carboxylic acid anhydride-based curing agents, the compound represented by formula (5) or formula (6) is preferred from the viewpoint of fluidity and transparency of the composition.
The alicyclic carboxylic acid anhydride curing agent can be used alone or in admixture of two or more.

In the present invention, as the carboxylic acid anhydride-based curing agent, one or more aliphatic carboxylic acid anhydride-based curing agents and aromatic carboxylic acid anhydride-based curing agents can be used. It is preferable to use in combination with an acid anhydride curing agent.
In addition, the aliphatic carboxylic acid anhydride-based curing agent and the aromatic carboxylic acid anhydride-based curing agent can be appropriately chemically modified as long as they do not substantially interfere with the curing reaction.
The total use ratio of the aliphatic carboxylic acid anhydride-based curing agent and the aromatic carboxylic acid anhydride-based curing agent is preferably 50% by weight or less based on the total amount with the alicyclic carboxylic acid anhydride-based curing agent, More preferably, it is 30 weight% or less.

  In this invention, the usage-amount of a carboxylic acid anhydride type hardening | curing agent is 0.7-1.5 preferably as an equivalent ratio of the carboxylic acid anhydride group with respect to 1 mol of epoxy groups in (A) alicyclic epoxy compound. More preferably, it is 0.8-1.3. In this case, even if the amount ratio is less than 0.7 or more than 1.5, there is a possibility that inconveniences such as a decrease in the glass transition point (Tg) and coloring of the obtained cured product may occur.

Furthermore, in the present invention, in addition to the carboxylic anhydride-based curing agent, components that are known as curing agents for epoxy compounds and epoxy resins (hereinafter referred to as “other curing agents”) within a range that does not impair the intended effects of the present invention. For example, phenols, dicyandiamides, and organic hydrazides such as adipic hydrazide and phthalic hydrazide can be used in combination.
The ratio of the other curing agent used is usually 50% by weight or less, preferably 30% by weight or less, based on the carboxylic acid anhydride curing agent.

(C) Curing accelerator The curing accelerator used in the present invention is a component that accelerates the curing reaction between (A) an alicyclic epoxy compound and (B) a carboxylic anhydride-based curing agent.
Such a curing accelerator is not particularly limited. For example, tertiary amines such as benzyldimethylamine, 2,4,6-tris (dimethylaminomethyl) phenol, dimethylcyclohexylamine; 1-cyanoethyl Imidazoles such as 2-ethyl-4-methylimidazole and 2-ethyl-4-methylimidazole; organophosphorus compounds such as triphenylphosphine and triphenyl phosphite; tetraphenylphosphonium bromide, tetra-n -Quaternary phosphonium salts such as butylphosphonium bromide; diazabicycloalkenes such as 1,8-diazabicyclo [5,4,0] undecene-7 and organic acid salts thereof; zinc octylate, tin actinate , Organometallic compounds such as aluminum acetylacetone complex; Quaternary ammonium salts such as ruammonium bromide and tetra-n-butylammonium bromide; Boron compounds such as boron trifluoride and triphenyl borate; Metal halides such as zinc chloride and stannic chloride, dicyandiamide and amines High melting point dispersion type latent curing accelerators such as amine addition type accelerators such as adducts of epoxy resin and epoxy resins; microcapsule type latent coatings with the surface of curing accelerators such as imidazole, phosphorus and phosphine coated with polymer Curable curing accelerators; amine salt type latent curing accelerators; latent curing accelerators such as high temperature dissociation type thermal cationic polymerization type latent curing accelerators such as Lewis acid salts and Bronsted acid salts it can.

Among these curing accelerators, quaternary phosphonium salts, diazabicycloalkenes, organometallic compounds and quaternary ammonium salts are colorless and transparent, and a cured product that is difficult to discolor even when heated for a long time can be obtained. preferable.
The said hardening accelerator can be used individually or in mixture of 2 or more types.
In this invention, the usage-amount of a hardening accelerator becomes like this. Preferably it is 0.1-6 weight part with respect to 100 weight part of (A) alicyclic epoxy compounds, More preferably, it is 0.3-4 weight part. In this case, if the amount of the curing accelerator used is less than 0.1 parts by weight, the curing rate tends to decrease. On the other hand, if it exceeds 6 parts by weight, there are disadvantages such as Tg reduction and coloring of the resulting cured product. May occur.

(D) Inorganic oxide particles The inorganic oxide particles used in the present invention are not particularly limited. For example, Si, Al, Zr, Ti, Zn, Ge, In, Sn, Sb, and Ce are used. Examples thereof include particles made of an oxide containing at least one element selected from the group, and more specifically, silica, alumina, zirconia, titanium oxide, zinc oxide, germanium oxide, indium oxide, tin oxide, Examples thereof include particles of indium-tin oxide (ITO), antimony oxide, antimony-tin oxide (ATO), cerium oxide, and the like.
Of these inorganic oxide particles, particles of silica, alumina, zirconia, antimony oxide and the like are preferable.
The inorganic oxide particles can be used after appropriate surface treatment such as alkylation, polysiloxylation, (meth) acryloyloxyalkylation, glycoxyalkylation, aminoalkylation and the like.
The said inorganic oxide particle can be used individually or in mixture of 2 or more types.
Further, if necessary, one or more dispersants such as an anionic surfactant, a cationic surfactant, a nonionic surfactant, and a polymer dispersant can be used together with the inorganic oxide particles.

  The primary average particle diameter of the inorganic oxide particles is 100 nm or less, preferably 1 to 80 nm. In this case, when the primary average particle diameter of the inorganic oxide particles exceeds 100 nm, the transparency of the resulting cured product may be impaired.

  In this invention, the usage-amount of an inorganic oxide particle becomes like this. Preferably it is 20-90 weight part with respect to 100 weight part of (A) alicyclic epoxy compounds, More preferably, it is 30-80 weight part. In this case, if the amount of the inorganic oxide particles used is less than 20 parts by weight, sufficient UV durability may not be obtained. May be difficult.

In the present invention, the inorganic oxide particles can be used for the preparation of a composition for optical semiconductor encapsulation as a dispersion liquid dispersed in an appropriate solvent.
The solvent is not particularly limited as long as it is inactive with respect to each component constituting the composition for optical semiconductor encapsulation of the present invention and a curing reaction and has an appropriate volatility.
Alcohols such as methanol, ethanol, i-propanol, n-butanol, n-octanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, propyl glycol monomethyl ether, propyl glycol monoethyl ether;
Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone;
Esters or lactones such as ethyl acetate, n-butyl acetate, ethyl lactate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, γ-butyrolactone;
Aromatic hydrocarbons such as benzene, toluene, xylenes;
Examples include amides such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and lactams.
These solvents can be used alone or in admixture of two or more.
The solid content concentration of the dispersion of inorganic oxide particles is usually 1 to 60% by weight, preferably 5 to 50% by weight.

Inorganic oxide particles and dispersions thereof are commercially available, and these commercially available products can also be used.
As a commercial item (trade name) of inorganic oxide particles, for example, as silica particle dispersion, methanol silica sol, IPA-ST, MEK-ST, NBA-ST, XBA-ST, DMAC-ST, ST-UP, ST-OUP, ST-20, ST-40, ST-C, ST-N, ST-O, ST-50, ST-OL (manufactured by Nissan Chemical Industries, Ltd.), organosol PL-2PGME (propylene glycol) A monomethyl ether dispersion (manufactured by Fuso Chemical Industry Co., Ltd.), etc. as silica particles, Aerosil 130, Aerosil 300, Aerosil 380, Aerosil TT600, Aerosil OX50 (above, Nippon Aerosil Co., Ltd.), Sildex H31, Sil Dex H32, Sildex H51, Sildex H52, Sildex H121, Sildec H122 (manufactured by Asahi Glass Co., Ltd.), E220A, E220 (manufactured by Nippon Silica Industry Co., Ltd.), SYLYSIA470 (manufactured by Fuji Silysia Co., Ltd.), SG flake (manufactured by Nippon Sheet Glass Co., Ltd.), etc. Can be mentioned.

  Also, alumina sol-100, alumina sol-200, alumina sol-520 (all of which are water dispersions, manufactured by Nissan Chemical Industries, Ltd.), AS-1501 (i-propanol dispersion, Sumitomo Osaka) Cement Co., Ltd.), AS-150T (toluene dispersion, manufactured by Sumitomo Osaka Cement Co., Ltd.), etc., as zirconia particle dispersion, HXU-110JC (toluene dispersion, manufactured by Sumitomo Osaka Cement Co., Ltd.), etc. As a dispersion of zinc antimonate particles, Celnax (aqueous dispersion, manufactured by Nissan Chemical Industries, Ltd.), etc. As a dispersion of cerium oxide particles, Nidral (aqueous dispersion, manufactured by Taki Chemical Co., Ltd.) ) And the like.

Other additives In the composition for optical semiconductor encapsulation of the present invention, if necessary, aliphatic polyols such as ethylene glycol and propylene glycol, aliphatic or the like, as long as the desired effects of the present invention are not impaired. Carbon dioxide generation inhibitors such as aromatic carboxylic acids and phenolic compounds; Flexibility imparting agents such as polyalkylene glycols and polydimethylsiloxane derivatives; Impact modifiers such as various rubbers and organic polymer beads, Antioxidants, plasticizers, lubricants, silane coupling agents, flame retardants, antistatic agents, leveling agents, ion trap agents, slidability improvers, far modification modifiers, surface tension reducing agents, antifoaming agents, anti-settling agents Other additives such as an agent, an ultraviolet absorber, an antioxidant, a release agent, a fluorescent agent, a colorant, and a conductive filler can be blended.

Preparation method of composition for optical semiconductor encapsulation The method for preparing the composition for optical semiconductor encapsulation of the present invention is not particularly limited, and can be prepared by mixing each component by a conventionally known method, For example,
[A] A method in which (A) component, (B) component, (C) component, (D) component and the like are mixed at the same time;
[B] Preliminary formulations (I) mainly composed of components (A) and (D) and preparatory formulations (II) mainly composed of components (B) and (C) were prepared separately. In addition, a method of mixing and preparing the pre-formulation (I) and the pre-formulation (II) before use can be employed.

In addition, when used as a dispersion in which inorganic oxide particles are dispersed in a solvent,
[C] After mixing the component (A), the component (B), the component (C), the dispersion, etc., the solvent in the dispersion is mixed under a temperature condition where the curing reaction does not proceed, for example, by distillation under reduced pressure. Removal and preparation method;
[D] After mixing the component (A), the dispersion, etc., the solvent in the dispersion is removed by, for example, evaporation, etc., and a pre-formulation mainly composed of the components (A) and (D) ( I), and a method of preparing the mixture by mixing (B) component, (C) component and the like;
[E] After mixing the component (A), the dispersion, etc., the solvent in the dispersion is removed, for example, by evaporation, etc., and a pre-formulation mainly comprising the components (A) and (D) ( Separately from this, a pre-blend (II) mainly comprising the components (B) and (C) is prepared, and the pre-blend (I) and the pre-blend (II) are prepared before use. A method of mixing and preparing can be employed.

Method for encapsulating an optical semiconductor When an optical semiconductor is encapsulated using the composition for encapsulating an optical semiconductor of the present invention, for example, the composition for encapsulating an optical semiconductor is formed at a predetermined position of the substrate on which the optical semiconductor layer is formed. Is applied, potted or impregnated, and then heated to be cured.
The construction method of the optical semiconductor sealing composition is not particularly limited, and for example, a known method such as application or potting with a dispenser, application by screen printing under vacuum or normal pressure, reaction injection molding, etc. is adopted. can do.

Moreover, it does not specifically limit as a method of hardening the composition for optical semiconductor sealing after construction, For example, conventionally well-known hardening apparatuses, such as a closed-type hardening furnace and a tunnel furnace which can be continuously hardened, are used. be able to.
The heating method for curing is not particularly limited, and conventionally known methods such as hot air circulation heating, infrared heating, and high frequency heating can be employed.
For example, the curing temperature and the curing time are preferably about 80 to 250 ° C. and about 30 seconds to 15 hours. Moreover, when aiming at reducing the internal stress of hardened | cured material, after making it harden | cure on the conditions of about 0.5 to 5 hours, for example at 80-120 degreeC, for example, at 120-180 degreeC, it is 0.1. It is preferable to perform post-curing under conditions of about 15 hours. Further, when aiming at short-time curing, for example, it is preferable to perform curing at 150 to 250 ° C. for about 30 seconds to 30 minutes.

  The composition for optical semiconductor encapsulation of the present invention has a cured product that is colorless and transparent and excellent in UV durability. For example, for sealing blue LEDs and white LEDs having a light emission peak wavelength in a wavelength region of 500 nm or less. It can be used very suitably.

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to these examples.
<Molding jig>
Two glass plates with a polyethylene terephthalate film attached to the surface were opposed to each other, and a silicon rubber rod having a diameter of 5 mm was sandwiched between the ends of the glass plate in a U shape to form a molding jig.
<Curing conditions>
The resin composition for sealing an optical semiconductor was poured into the molding jig and cured by heating in an oven at 140 ° C. for 2 hours.
<Evaluation of UV durability>
The cured product was irradiated with an ultra-high pressure mercury lamp for 1 week, and the presence or absence of transparency or coloring was visually evaluated.

Example 1
(A) 40 parts by weight of a compound represented by the formula (2) as a component (trade name CE2021, manufactured by Daicel Chemical Industries, Ltd.), and (D) a propylene glycol monomethyl ether of silica particles having a primary average particle size of 20 nm as a component 240 parts by weight of dispersion (trade name Organosol PL-2PGME, solid content concentration 25.0% by weight, manufactured by Fuso Chemical Co., Ltd.), 9,10-dihydro-9-oxa-10-phosphaphenanthrene as an antioxidant After uniformly dissolving 0.3 parts by weight of -10-oxide and 0.3 parts by weight of 2,6-di-tert-butyl-4-methylphenol, the propylene glycol monomethyl ether was removed by an evaporator, and viscosity was increased. A pre-formulation (I) consisting of a liquid was obtained. Thereafter, 36 parts by weight of methylhexahydrophthalic anhydride (trade name MH-700, manufactured by Shin Nippon Rika Co., Ltd.) as component (B) and tetra-n as component (C) were added to this pre-blend (I). -0.36 parts by weight of butylphosphonium bromide (trade name Hishicolin PX-4ET, manufactured by Nippon Chemical Industry Co., Ltd.), mixed, poured into a molding jig, cured, and cured in a transparent and non-colored manner Got. The cured product was transparent and uncolored even when UV irradiation was performed for 1 week.

Example 2 and Example 3
A cured product was obtained and evaluated in the same manner as in Example 1 except that the components (A), (B), (C), and (D) shown in Table 1 were used. The evaluation results are shown in Table 1.

Comparative Example 1
Using the (A) component, the (B) component, and the (C) component shown in Table 1, except that the (D) component was not added, a cured product was obtained and evaluated in the same manner as in Example 1. . The evaluation results are shown in Table 1.

In Table 1, each component (trade name) other than the components used in Example 1 is as follows.
(A) Component CE3000: Compound represented by the above formula (3) HBE100: Compound represented by the above formula (1)
Component (D) Organosol PL1-IPA: Dispersion in which silica particles having a primary average particle size of 12 nm are dispersed in isopropanol (solid content concentration 12.6% by weight, manufactured by Fuso Chemical Industry Co., Ltd.)

Claims (3)

  It comprises (A) an alicyclic epoxy compound, (B) a carboxylic anhydride-based curing agent, (C) a curing accelerator, and (D) inorganic oxide particles having a primary average particle size of 100 nm or less. Composition for optical semiconductor encapsulation.   The composition for encapsulating an optical semiconductor according to claim 1, wherein the content of the component (D) is 20 to 90% by weight with respect to the component (A).   The composition for optical semiconductor encapsulation according to claim 1, wherein the inorganic oxide particles are silica.