JP2011178892A - Sealing agent for optical semiconductor element and optical semiconductor device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing agent for optical semiconductor elements having excellent gas barrier properties. <P>SOLUTION: The sealing agent for optical semiconductor elements contains a silicone resin having at least one cyclic ether-containing group in one molecule and a liquid phenol resin, wherein the silicone resin contains a resin whose average composition formula is represented by general formula (1) and a content ratio of phenyl groups obtained by the following expression (a) is 15-60 mol%. In general formula (1), a, b and c satisfy a/(a+b+c)=0-0.3, b/(a+b+c)=0.5-0.9 and c/(a+b+c)=0.1-0.4, at least one of R<SP>1</SP>to R<SP>6</SP>represents a cyclic ether-containing group and/or a phenyl group, R<SP>1</SP>to R<SP>6</SP>except the cyclic ether-containing group and phenyl group represent a linear or branched 1-8C hydrocarbon group or a fluoride group of a linear or branched 1-8C hydrocarbon group, and R<SP>1</SP>to R<SP>6</SP>may be the same or different. (Content ratio (mol%) of phenyl groups)=[(average number of phenyl groups contained in one molecule of resin whose average composition formula is represented by general formula (1))×(molecular weight of phenyl group)/(average molecular weight of resin whose average composition formula is represented by general formula (1))]×100 (expression (a)). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical semiconductor element sealing agent used for sealing an optical semiconductor element which is a light emitting element in an optical semiconductor device, and an optical semiconductor device using the optical semiconductor element sealing agent.

  Optical semiconductor elements such as light emitting diodes (LEDs) are widely used in backlights for mobile phones. In addition, an optical semiconductor device using an optical semiconductor element has low power consumption and a long lifetime. Therefore, the optical semiconductor device is used in a wide range of applications such as automobile lamps, lighting equipment, or signboards. Therefore, the optical semiconductor device is required to be usable even in a harsher environment.

  When an optical semiconductor element (for example, LED) used in an optical semiconductor device is in direct contact with the atmosphere, the light emission characteristics of the optical semiconductor element rapidly deteriorate due to moisture in the atmosphere or floating dust. For this reason, the said optical semiconductor element is normally sealed with the sealing compound for optical semiconductor elements.

  Patent Document 1 listed below discloses an epoxy resin material containing hydrogenated bisphenol A glycidyl ether, an alicyclic epoxy monomer, and a latent catalyst as a sealant for an optical semiconductor element. This epoxy resin material is cured by thermal cationic polymerization.

  On the other hand, instead of an epoxy resin, a method is known in which a silicone resin that has a high transmittance with respect to light having a short wavelength in the blue to ultraviolet region and is excellent in heat resistance and light resistance is used as a sealant for sealing an LED.

  For example, Patent Document 2 below discloses a silicone resin-based optical semiconductor element encapsulant with an increased crosslinking density.

JP 2003-73452 A JP 2001-314142 A

  When the conventional sealing agent for optical semiconductor elements as described in Patent Documents 1 and 2 is used in a harsh environment that is repeatedly subjected to heating and cooling, the sealing agent may crack or It may peel off from the housing material.

  In an optical semiconductor device, in order to reflect light reaching the back side of the light emitting element, an electrode made of silver or an alloy mainly composed of silver or a silver plated electrode is formed on the back side of the light emitting element. is there. When the sealant cracks or the sealant peels from the housing material, the electrode is exposed to the atmosphere. In this case, silver may be discolored by a corrosive gas such as hydrogen sulfide gas or sulfurous acid gas present in the atmosphere. When the color of the electrode changes, the reflectance decreases, which causes a problem that the brightness of the light emitted from the light emitting element decreases.

  An object of the present invention is to provide an optical semiconductor element encapsulant that is excellent in gas barrier properties and hardly causes discoloration of electrodes due to a corrosive gas, and an optical semiconductor device using the optical semiconductor element encapsulant. .

  According to a wide aspect of the present invention, the silicone resin contains one or more cyclic ether-containing groups in the molecule and a liquid phenol resin, and the silicone resin has an average composition formula of the following general formula (1): Provided is an encapsulant for optical semiconductor elements, which contains a resin represented by the formula (a) and has a phenyl group content of 15 to 60 mol%.

In the general formula (1), a, b, and c are a / (a + b + c) = 0 to 0.3, b / (a + b + c) = 0.5 to 0.9, and c / (a + b + c) = 0. 1 to 0.4 are satisfied, and at least one of R ^{1 to} R ⁶ represents a cyclic ether-containing group and / or a phenyl group, and R ^{1 to} R ⁶ other than the cyclic ether-containing group and the phenyl group are linear Represents a linear or branched hydrocarbon group having 1 to 8 carbon atoms or a linear or branched hydrocarbon group having 1 to 8 carbon atoms. R ^{1 to} R ⁶ may be the same or different.

  Phenyl group content ratio (mol%) = (average number of phenyl groups contained in one molecule of resin whose average composition formula is represented by general formula (1) × molecular weight of phenyl group / average composition formula is general formula ( 1) Average molecular weight of the resin component represented by 1) × 100 Formula (a)

  In a specific aspect of the sealant for optical semiconductor elements according to the present invention, the liquid phenol resin is an alkoxysilane-modified phenol resin produced by reacting a silicon compound having an alkoxy group with a phenol resin. . In this case, the gas barrier property can be further enhanced. As the silicon compound having an alkoxy group, a trialkoxysilane compound or a tetraalkoxysilane compound is preferably used, whereby the gas barrier properties can be effectively enhanced.

  More preferably, the trialkoxysilane compound preferably contains a phenyl group. Thereby, the gas barrier property can be further enhanced.

  An optical semiconductor device according to the present invention includes an optical semiconductor element, and an optical semiconductor element sealing agent that is provided to seal the optical semiconductor element and is configured according to the present invention.

  The encapsulant for optical semiconductor elements according to the present invention contains a silicone resin having at least one cyclic ether-containing group in the molecule and a liquid phenol resin, and the silicone resin has the above specific average composition formula, Since the phenyl group content is 15 to 60 mol%, the gas barrier property is excellent.

  Therefore, when an optical semiconductor device is configured by sealing an optical semiconductor element such as a light emitting diode using the optical semiconductor element sealing agent according to the present invention, the electrode is hardly discolored by a corrosive gas or the like. Therefore, it is possible to suppress a decrease in brightness of the optical semiconductor device. In addition, since the gas barrier property is excellent as described above, it is possible to provide an optical semiconductor device that can stably exhibit performance even under a harsh environment exposed to a corrosive gas.

FIG. 1 is a front sectional view showing an optical semiconductor device according to an embodiment of the present invention.

  Details of the present invention will be described below.

[Silicone resin (A) having at least one cyclic ether-containing group in the molecule]
The sealing agent for optical semiconductor elements which concerns on this invention contains the specific silicone resin (A) which has a 1 or more cyclic ether containing group in a molecule | numerator. This silicone resin (A) is a resin whose average composition formula is represented by the following formula (1).

In the above formula (1), a, b and c are a / (a + b + c) = 0 to 0.3, b / (a + b + c) = 0.5 to 0.9, and c / (a + b + c) = 0. 1 to 0.4 is satisfied, and at least one of R ^{1 to} R ⁶ represents a cyclic ether-containing group and / or a phenyl group, and R ^{1 to} R ⁶ other than the cyclic ether-containing group and the phenyl group are linear Represents a linear or branched hydrocarbon group having 1 to 8 carbon atoms or a linear or branched hydrocarbon group having 1 to 8 carbon atoms. R ^{1 to} R ⁶ in the above formula (1) may be the same or different.

When the resin represented by the formula (1) has a cyclic ether-containing group and a phenyl group in the same molecule, at least one of R ^{1 to} R ⁶ in the formula (1) contains a cyclic ether. R ^{1 to} R ⁶ other than the cyclic ether-containing group and the phenyl group are each a linear or branched hydrocarbon group having 1 to 8 carbon atoms or a straight chain. Represents a branched or branched hydrocarbon group having 1 to 8 carbon atoms.

  In the resin whose average composition formula is represented by the above formula (1), the content ratio of the phenyl group determined from the following formula (a) is 15 to 60 mol%. The preferable lower limit of the phenyl group content is 20 mol%, and the preferable upper limit is 55 mol%. When the content ratio of the phenyl group satisfies the preferable lower limit, the gas barrier property of the sealant can be further enhanced. When the content ratio of the phenyl group satisfies the preferable upper limit, peeling of the sealant is difficult to occur.

  Phenyl group content ratio (mol%) = (average number of phenyl groups contained in one molecule of resin whose average composition formula is represented by general formula (1) × molecular weight of phenyl group / average composition formula is general formula ( 1) Average molecular weight of the resin component represented by 1) × 100 Formula (a)

  The hydrocarbon group having 1 to 8 carbon atoms is not particularly limited. For example, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, Examples include n-octyl group, isopropyl group, isobutyl group, sec-butyl group, t-butyl group, isopentyl group, neopentyl group, t-pentyl group, isohexyl group, and cyclohexyl group.

  The silicone resin (A) has at least one cyclic ether-containing group in the molecule. The cyclic ether-containing group is not particularly limited, and examples thereof include cyclic ether-containing groups such as a glycidyl-containing group, an epoxycyclohexyl-containing group, and an oxetane-containing group. Of these, a glycidyl-containing group or an epoxycyclohexyl-containing group is preferable.

  The cyclic ether-containing group is a functional group containing a cyclic ether group in a part of the skeleton. The cyclic ether-containing group may be, for example, a functional group that includes a cyclic ether group in the skeleton and also includes another skeleton such as an alkyl group or an alkyl ether group.

  The glycidyl-containing group is not particularly limited. For example, 2,3-epoxypropyl group, 3,4-epoxybutyl group, 4,5-epoxypentyl group, 2-glycidoxyethyl group, 3-glycidoxy A propyl group, 4-glycidoxybutyl group, etc. are mentioned.

  The epoxycyclohexyl-containing group is not particularly limited, and examples thereof include a 2- (3,4-epoxycyclohexyl) ethyl group or a 3- (3,4-epoxycyclohexyl) propyl group.

From the viewpoint of further increasing the thermal shock resistance of the sealant, the cyclic ether-containing group is 2- (
It is preferably a 3,4-epoxycyclohexyl) ethyl group.

  The preferable lower limit of the content ratio of the cyclic ether-containing group in the resin whose average composition formula is represented by the formula (1) is 0.1 mol%, the more preferable lower limit is 1 mol%, and the preferable upper limit is 50 mol%, more preferable. The upper limit is 30 mol%. When the content ratio of the cyclic ether-containing group satisfies the preferable lower limit, the reactivity between the silicone resin and a liquid phenol resin (B) as a thermosetting agent described later is sufficiently high, and the curability of the sealant is increased. It can be further increased. When the content ratio of the cyclic ether-containing group satisfies the above preferable upper limit, the cyclic ether-containing group that does not participate in the reaction between the silicone resin (A) and the liquid phenol resin (B) decreases, so the heat resistance of the sealant Becomes higher.

  The content ratio of the cyclic ether-containing group is a ratio of the cyclic ether-containing group contained in the resin whose average composition formula is represented by the formula (1). Specifically, the ratio is obtained based on the following formula (b).

  Content ratio (mol%) of cyclic ether-containing group = (average number of cyclic ether-containing groups contained in one molecule of the resin whose average composition formula is represented by the above formula (1) × molecular weight of cyclic ether-containing group / average The average molecular weight of the resin whose composition formula is represented by the above formula (1)) × 100 Formula (b)

In the silicone resin (A) represented by the above formula (1), a structural unit represented by (R ⁴ R ⁵ SiO _2/2 ) (hereinafter also referred to as a bifunctional structural unit) is represented by the following formula (1-2): ), That is, a structural unit in which one of oxygen atoms bonded to a silicon atom in the bifunctional structural unit constitutes a hydroxyl group or an alkoxy group is also included in the bifunctional structural unit.

_{^{(R 4 R 5 SiXO 1/2)}} ... formula (1-2)

In the above formula (1-2), X represents OH or OR, and OR represents a linear or branched alkoxy group having 1 to 4 carbon atoms. R ⁴ and R ⁵ in the formula (1-2) are a cyclic ether-containing group, a phenyl group, a linear or branched hydrocarbon group having 1 to 8 carbon atoms, or a linear or branched carbon. It is a hydrocarbon group having a fluorine atom of number 1-8.

In the silicone resin (A), the structural unit represented by (R ⁶ SiO _3/2 ) (hereinafter also referred to as trifunctional structural unit) is represented by the following formula (1-3) or (1-4). A structure in which two of the oxygen atoms bonded to the silicon atom in the trifunctional structural unit constitute a hydroxyl group or an alkoxy group, respectively, or one of the oxygen atoms bonded to the silicon atom in the trifunctional structural unit is A structural unit constituting a hydroxyl group or an alkoxy group is also included in the bifunctional structural unit.

^{_{(R 6 SiX 2 O 1/2)}} ... formula (1-3)
(R ⁶ SiXO _2/2 ) Formula (1-4)

In the above formulas (1-3) and (1-4), X represents OH or OR, and OR represents a linear or branched alkoxy group having 1 to 4 carbon atoms. R ⁶ in the above formulas (1-3) and (1-4) is a cyclic ether-containing group, a phenyl group, a linear or branched hydrocarbon group having 1 to 8 carbon atoms, or a linear or branched group. It is a hydrocarbon group having a fluorine atom having 1 to 8 carbon atoms.

  In the above formulas (1-2) to (1-4), the linear or branched alkoxy group having 1 to 4 carbon atoms is not particularly limited, and examples thereof include a methoxy group, an ethoxy group, an n-propoxy group, Examples thereof include n-butoxy group, isopropoxy group, isobutoxy group, sec-butoxy group and t-butoxy group.

In the above formula (1), the lower limit of a / (a + b + c) is 0, and the upper limit is 0.3. When a / (a + b + c) satisfies the above upper limit, the heat resistance of the sealant can be further increased, and peeling of the sealant can be further suppressed. A more preferred upper limit is 0.25, and even more preferred is 0.2. When a is 0, the structural unit of (R ¹ R ² R ³ SiO _1/2 ) _a does not exist in the above formula (1).

  In the above formula (1), the lower limit of b / (a + b + c) is 0.5, and the upper limit is 0.9. When b / (a + b + c) satisfies the above lower limit, the cured product of the sealant does not become too hard, and cracks are hardly generated in the sealant. When b / (a + b + c) satisfies the above upper limit, the gas barrier property of the sealant is further enhanced. A more preferred lower limit is 0.6, and a more preferred upper limit is 0.85.

  In the above formula (1), the lower limit of c / (a + b + c) is 0.1, and the upper limit is 0.4. When c / (a + b + c) satisfies the above upper limit, it is easy to maintain an appropriate viscosity as a sealant, and adhesion can be further enhanced. A more preferred upper limit is 0.35, and a more preferred upper limit is 0.3.

When ²⁹ Si-nuclear magnetic resonance analysis (hereinafter referred to as NMR) is performed on the basis of tetramethylsilane (hereinafter referred to as TMS) with respect to the silicone resin (A) represented by the above formula (1), it may slightly vary depending on the type of substituent. Although fluctuation is observed, a peak corresponding to the structural unit represented by (R ¹ R ² R ³ SiO _1/2 ) _a in the above formula (1) appears in the vicinity of +10 to 0 ppm, and in the above formula (1) (R ⁴ R ⁵ SiO _2/2 ) _b and each peak corresponding to the bifunctional structural unit of (1-2) appear in the vicinity of −10 to −50 ppm, and (R ⁶ SiO _{3 in the} above formula (1) _{/ 2} ) _c , and peaks corresponding to the trifunctional structural units of (1-3) and (1-4) appear in the vicinity of −50 to −80 ppm.

Therefore, ²⁹ Si-NMR is measured, and the ratio of each structural unit in the above formula (1) can be measured by comparing the peak areas of the respective signals.

However, in the case where the structural unit in the formula (1) cannot be identified by the ²⁹ Si-NMR measurement based on the TMS, not only the ²⁹ Si-NMR measurement result but also ¹ H-NMR and ¹⁹ F The ratio of each structural unit in the above formula (1) can be determined by using the measurement result of -NMR as necessary.

  The preferable lower limit of the content of the alkoxy group in the resin whose average composition formula is represented by the formula (1) is 0.5 mol%, the more preferable lower limit is 1 mol%, the preferable upper limit is 10 mol%, and the more preferable upper limit is 5 Mol%. When the content of the alkoxyl group is within the preferable range, the heat resistance and light resistance of the sealant are dramatically improved. This is presumably because the silicone resin (A) contains an alkoxy group, so that the curing rate can be drastically improved, thereby preventing thermal deterioration during curing. Further, when the curing rate is remarkably increased, sufficient curability can be obtained even with a relatively small addition amount when a curing accelerator is added.

  When the content of the alkoxy group satisfies the above preferable lower limit, the curing rate of the sealant is sufficiently increased, and the heat resistance of the sealant is improved. When content of an alkoxyl group satisfy | fills the said preferable upper limit, the storage stability of a silicone resin (A) and the sealing agent after preparation will become high, and the heat resistance of sealing agent will become still higher.

  Content of the said alkoxy group means the quantity of the said alkoxy group contained in resin whose average composition formula is represented by Formula (1).

  The silicone resin (A) preferably does not contain a silanol group. When the silicone resin (A) does not contain a silanol group, the storage stability of the silicone resin and the prepared sealant is increased. The silanol group can be reduced by heating under vacuum. The content of silanol groups can be measured using infrared spectroscopy.

  The preferable lower limit of the number average molecular weight (Mn) of the silicone resin (A) is 1000, the more preferable lower limit is 1500, the preferable upper limit is 50000, and the more preferable upper limit is 15000. When the number average molecular weight of the silicone resin (A) satisfies the above preferable lower limit, the volatile components are reduced at the time of thermosetting, and the film loss due to curing is reduced. When the number average molecular weight of the silicone resin (A) satisfies the preferable upper limit, the viscosity can be easily adjusted.

  The said number average molecular weight (Mn) is the value calculated | required based on the analytical curve created using the gel as a standard substance using gel permeation chromatography (GPC). The number average molecular weight (Mn) was measured using two measuring devices manufactured by Waters (column: Shodex GPC LF-804 (length: 300 mm) manufactured by Showa Denko KK), measuring temperature: 40 ° C., flow rate: 1 mL / min, solvent: Tetrahydrofuran, standard substance: polystyrene).

  The method for synthesizing the silicone resin (A) is not particularly limited. For example, a first method of introducing a substituent by a hydrosilylation reaction between a silicone resin having a SiH group and a vinyl compound having a cyclic ether-containing group. And a second method in which an organosilicon compound and an organosilicon compound having a cyclic ether-containing group are subjected to a condensation reaction.

  In the first method, the hydrosilylation reaction is a method in which a SiH group and a vinyl group are reacted in the presence of a catalyst as necessary.

  The silicone resin having a SiH group is one that contains a SiH group in the molecule and becomes the silicone resin (A) after reacting the vinyl compound having the cyclic ether-containing group. Use it.

  The vinyl compound having a cyclic ether-containing group is not particularly limited as long as it is a vinyl compound having one or more cyclic ether-containing groups in the molecule. For example, vinyl glycidyl ether, allyl glycidyl ether, glycidyl methacrylate, glycidyl acrylate Alternatively, an epoxy group-containing compound such as vinylcyclohexene oxide can be used.

  In the second method, as a specific method for the condensation reaction between an organosilicon compound having no cyclic ether skeleton and an organosilicon compound having a cyclic ether-containing group, for example, an organic compound having no cyclic ether-containing group is used. Examples thereof include a method in which a silicon compound and an organic silicon compound having a cyclic ether-containing group are reacted in the presence of water and an acidic catalyst or a basic catalyst.

  Examples of the organosilicon compound that is used in obtaining the silicone resin (A) and does not have a cyclic ether-containing group include trimethylmethoxysilane, trimethylethoxysilane, triphenylmethoxysilane, triphenylethoxysilane, and dimethyldimethoxysilane. , Dimethyldiethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, isopropyl (methyl) dimethoxysilane, cyclohexyl (methyl) dimethoxysilane, methyl (phenyl) dimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane , Ethyltriethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, phenyltrimethoxysilane, and the like.

  Furthermore, examples of the organosilicon compound having a cyclic ether-containing group that are used in obtaining the silicone resin (A) include 3-glycidoxypropyl (dimethyl) methylmethoxysilane and 2- (3,4-epoxy). (Cyclohexyl) ethyl (dimethyl) methoxysilane, 3-glycidoxypropyl (methyl) dimethoxysilane, 3-glycidoxypropyl (methyl) diethoxysilane, 3-glycidoxypropyl (methyl) dibutoxysilane, 2,3 -Epoxypropyl (methyl) dimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl (methyl) dimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyl (methyl) diethoxysilane, 3-glycidoxypropyl Trimethoxysilane, 3-glycidoxypropyltri Tokishishiran, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane or 2- (3,4-epoxycyclohexyl) ethyl triethoxy silane.

  Examples of the acidic catalyst include inorganic acids, organic acids, acid anhydrides or derivatives of inorganic acids, and acid anhydrides or derivatives of organic acids.

  Examples of the inorganic acid include phosphoric acid, boric acid, and carbonic acid. Examples of the organic acid include formic acid, acetic acid, propionic acid, butyric acid, lactic acid, malic acid, tartaric acid, citric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid or oleic acid Is mentioned.

  Examples of the basic catalyst include alkali metal hydroxides, alkali metal alkoxides, and alkali metal silanol compounds.

  Examples of the alkali metal hydroxide include sodium hydroxide, potassium hydroxide, and cesium hydroxide. Examples of the alkali metal alkoxide include sodium-t-butoxide, potassium-t-butoxide, and cesium-t-butoxide.

  Examples of the alkali metal silanol compound include a sodium silanolate compound, a potassium silanolate compound, and a cesium silanolate compound. Of these, potassium-based catalysts and cesium-based catalysts are preferred.

[Liquid phenolic resin (B)]
The encapsulant for optical semiconductor elements according to the present invention contains a liquid phenol resin (B). The liquid phenol resin (B) acts as a thermosetting agent capable of reacting with the cyclic ether-containing group. Therefore, the encapsulant for optical semiconductor elements according to the present invention is a thermosetting composition.

  The phenol resin (B) is not particularly limited as long as it is liquid.

  As for the said liquid phenol resin (B), only 1 type may be used and 2 or more types may be used together.

  Preferably, as the liquid phenolic resin (B), an alkoxysilane-modified phenolic resin produced by reacting a silicon compound having an alkoxy group with a phenolic resin is used. In that case, the gas barrier property is more effective. Can be enhanced. Examples of the silicon compound having an alkoxy group include trialkoxysilane compounds such as tetraalkoxysilane compounds, dialkoxysilane compounds, and monoalkoxysilane compounds.

  As the silicon compound having an alkoxy group, a trialkoxysilane compound or a tetraalkoxysilane compound is more preferably used. Thereby, the gas barrier property can be further enhanced.

  Examples of the trialkoxysilane compound include trimethoxysilane, triethoxysilane, and trimethoxymethylsilane.

  Examples of the tetraalkoxysilane compound include tetramethoxysilane, tetraethoxysilane, and tetrapropoxysilane.

  More preferably, a trialkoxysilane compound containing a phenyl group is used as the silicon compound having an alkoxy group. Thereby, the gas barrier property can be further enhanced.

  Examples of such a trialkoxysilane compound containing a phenyl group include phenyltrimethoxysilane, phenyltriethoxysilane, and trimethoxy [3- (phenylamino) propyl] silane.

  The phenol resin that reacts with the silicon compound having an alkoxy group to produce an alkoxysilane-modified phenol resin is not particularly limited, and is bisphenol such as bisphenol A, bisphenol C, bisphenol M, phenol novolac, cresol novolac, bisphenol. A novolak, brominated phenol novolak, brominated bisphenol A novolak and the like can be used.

  The content of the liquid phenol resin (B) is not particularly limited. The preferable lower limit of the content of the liquid phenolic resin (B) is 1 part by weight, the more preferable lower limit is 5 parts by weight, the preferable upper limit is 70 parts by weight, and the more preferable upper limit is 50 parts by weight with respect to 100 parts by weight of the silicone resin (A). Parts by weight. When content of a liquid phenol resin (B) satisfy | fills the said preferable minimum and upper limit, the crosslinking reaction in sealing agent will fully advance, while heat resistance and light resistance will become high, and a water vapor transmission rate will become low enough.

  Moreover, in the sealing agent for optical semiconductor elements which concerns on this invention, you may use another thermosetting agent together with the said liquid phenol resin (B). Examples of such other thermosetting agents include aliphatic amines, aromatic amines, mercapto compounds, acid anhydrides, imidazoles, amine adducts, hydrazines, tertiary amines, organic phosphines, and dicyandiamide.

(Curing accelerator)
The encapsulant for optical semiconductor elements according to the present invention preferably further contains a curing accelerator.

  The curing accelerator is not particularly limited, and examples thereof include imidazoles, tertiary amines and salts of the tertiary amines, phosphonium salts, aminotriazoles, metal catalysts and the like. As for a hardening accelerator, only 1 type may be used and 2 or more types may be used together.

  Examples of the imidazoles include 2-methylimidazole and 2-ethyl-4-methylimidazole. Examples of the tertiary amines include 1,8-diazabicyclo (5,4,0) undecene-7. Examples of the phosphines include triphenylphosphine. Examples of the phosphonium salts include triphenylphosphonium bromide. Examples of the metal catalysts include tin-based metal catalysts such as tin octylate and dibutyltin dilaurate, zinc-based metal catalysts such as zinc octylate, and acetylacetonates such as aluminum, chromium, cobalt, and zirconium. .

  The content of the curing accelerator is not particularly limited. The preferable lower limit of the content of the curing accelerator is 0.01 parts by weight, the more preferable lower limit is 0.05 parts by weight, the preferable upper limit is 5 parts by weight, and the more preferable upper limit is 1 part with respect to 100 parts by weight of the silicone resin (A). .5 parts by weight. If content of a hardening accelerator satisfy | fills the said preferable minimum, the addition effect of a hardening accelerator can fully be acquired. When content of the said effect accelerator satisfy | fills the said preferable upper limit, it will become difficult to color the hardened | cured material of sealing agent, and also it will become difficult to reduce heat resistance and light resistance.

(Coupling agent)
The encapsulant for optical semiconductor elements according to the present invention may further contain a coupling agent in order to impart adhesiveness.

  It does not specifically limit as said coupling agent, For example, a silane coupling agent etc. are mentioned. Examples of the silane coupling agent include vinyltriethoxysilane, vinyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and γ-methacryloxypropyltrimethoxy. Silane, N-phenyl-3-aminopropyltrimethoxysilane, etc. are mentioned. As for a coupling agent, only 1 type may be used and 2 or more types may be used together.

  The preferable lower limit of the content of the coupling agent is 0.1 parts by weight and the preferable upper limit is 5 parts by weight with respect to 100 parts by weight of the silicone resin (A). When the content of the coupling agent is 0.1 parts by weight or more, the effect of adding the coupling agent is sufficiently exhibited. When the content of the coupling agent is 5 parts by weight or less, the excess coupling agent is less likely to volatilize, and when the sealant is cured, the thickness of the cured product is less likely to be reduced in a high temperature environment. Become.

(Other ingredients)
The encapsulant for optical semiconductor elements according to the present invention may contain a curable compound other than the silicone resin (A) as long as the effects of the present invention are not hindered. Examples of the curable compound include compounds having an amino group, a urethane group, an imide group, a hydroxyl group, a carboxyl group, or an epoxy group. Among these, an epoxy compound is preferable. A conventionally well-known epoxy compound can be used for an epoxy compound, and it is not specifically limited.

  The encapsulant for optical semiconductor elements according to the present invention may further contain a phosphor. The phosphor absorbs light emitted from the light emitting element encapsulated with the encapsulant for optical semiconductor elements of the present invention and generates fluorescence, thereby finally obtaining light of a desired color. Acts as follows. The phosphor is excited by light emitted from the light emitting element to emit fluorescence, and light of a desired color can be obtained by a combination of light emitted from the light emitting element and fluorescence emitted from the phosphor.

  For example, when it is intended to finally obtain white light using an ultraviolet LED chip as a light emitting element, it is preferable to use a combination of a blue phosphor, a red phosphor and a green phosphor. When it is intended to finally obtain white light using a blue LED chip as a light emitting element, it is preferable to use a combination of a green phosphor and a red phosphor, or a yellow phosphor. As for the said fluorescent substance, only 1 type may be used and 2 or more types may be used together.

The blue phosphor is not particularly limited. For example, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, (Ba, Sr) MgAl ₁₀ O ₁₇ : Eu, (Sr, Ba) ₃ MgSi ₂ O ₈ : Eu and the like.

The red phosphor is not particularly limited. For example, (Sr, Ca) S: Eu, (Ca, Sr) ₂ SI ₅ N ₈ : Eu, CaSiN ₂ : Eu, CaAlSiN ₃ : Eu, Y ₂ O ₂ S : Eu, La ₂ O ₂ S: Eu, LiW ₂ O ₈ : (Eu, Sm), (Sr, Ca, Bs, Mg) ₁₀ (PO ₄ ) ₈ Cl ₂ : (Eu, Mn), Ba ₃ MgSi ₂ And O ₈ : (Eu, Mn).

The green phosphor is not particularly limited, and for example, Y ₃ (Al, Ga) ₅ O ₁₂ : Ce, SrGa ₂ S ₄ : Eu, Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce, SrSiON: Eu, ZnS: (Cu, Al), BaMgAl ₁₀ O ₁₇ (Eu, Mn), SrAl ₂ O ₄ : Eu, and the like.

Is not particularly restricted but includes the yellow phosphor, for _{example, Y 3 Al 5 O 12:} Ce, (Y, Gd) 3 Al 5 O 12: Ce, Tb 3 A l5 O 12: Ce, CaGa 2 S 4: Eu , Sr ₂ SiO ₄ : Eu, and the like.

  Furthermore, examples of the phosphor include perylene compounds that are organic phosphors.

  The optical semiconductor element sealant according to the present invention includes a dispersant, an antioxidant, an antifoaming agent, a colorant, a modifier, a leveling agent, a light diffusing agent, a thermally conductive filler, a flame retardant, and the like as necessary. The additive may be further contained.

  In addition, the sealing agent for optical semiconductor elements prepared separately the A liquid which has the said cyclic ether containing group and the silicone resin which has a phenyl group as a main component, and B liquid which has the said liquid phenol resin (B) as a main component. A liquid A and a B liquid may be mixed and adjusted immediately before use.

  The curing temperature of the encapsulant for optical semiconductor elements according to the present invention is not particularly limited. The preferable lower limit of the curing temperature of the encapsulant for optical semiconductor elements is 80 ° C, the more preferable lower limit is 100 ° C, the preferable upper limit is 180 ° C, and the more preferable upper limit is 150 ° C. When the curing temperature satisfies the above preferable lower limit, curing of the sealant proceeds sufficiently. When the curing temperature satisfies the above preferable upper limit, the package is unlikely to be thermally deteriorated.

  Although it does not specifically limit to hardening, It is preferable to use a step cure system. The step cure method is a method in which the resin is temporarily cured at a low temperature and then cured at a high temperature. By using the step cure method, curing shrinkage of the sealant can be suppressed.

  The method for producing the encapsulant for optical semiconductor elements according to the present invention is not particularly limited.For example, using a mixer such as a homodisper, a homomixer, a universal mixer, a planetarium mixer, a kneader, a three roll, a bead mill, Examples include a method of mixing the above-described silicone resin, thermosetting agent, and other components blended as necessary at room temperature or under heating.

  Since the encapsulant for optical semiconductor elements according to the present invention has the above composition, it has excellent gas barrier properties. Therefore, permeation of corrosive gas existing in the atmosphere such as hydrogen sulfide gas or sulfuric acid gas can be suppressed. In general, an electrode whose surface is made of silver, for example, an electrode made of silver or an alloy composed mainly of silver, or an electrode having a silver plating layer on its surface changes color when exposed to these corrosive gases. However, according to this invention, since the permeation | transmission of the said corrosive gas is suppressed, discoloration of the electrode which the surface consists of silver can be suppressed reliably. Therefore, it is possible to suppress a decrease in reflectance due to the electrodes, and it is possible to suppress a decrease in brightness of light emitted from the optical semiconductor element.

  The optical semiconductor element to which the present invention is applied is not particularly limited as long as it is a light emitting element using a semiconductor. For example, when the light emitting element is a light emitting diode, for example, an LED type semiconductor material is laminated on a substrate. Structure. In this case, examples of the semiconductor material include GaAs, GaP, GaAlAs, GaAsP, AlGaInP, GaN, InN, AlN, InGaAlN, and SiC.

  Examples of the substrate include sapphire, spinel, SiC, Si, ZnO, and GaN single crystal. In addition, a buffer layer may be formed between the substrate and the semiconductor material as necessary. Examples of the buffer layer include GaN and AlN.

  Specific examples of the optical semiconductor device according to the present invention include a light emitting diode device, a semiconductor laser device, and a photocoupler. Such optical semiconductor devices include, for example, backlights for liquid crystal displays, illumination, various sensors, light sources for printers, copiers, etc., vehicle measuring instrument light sources, signal lights, indicator lights, display devices, and light sources for planar light emitters. It can be suitably used for displays, decorations, various lights or switching elements.

(Embodiment of optical semiconductor device)
FIG. 1 is a front sectional view showing an optical semiconductor device according to an embodiment of the present invention.

  The optical semiconductor device 1 of this embodiment has a housing 2. An optical semiconductor element 3 made of LED is mounted in the housing 2. An inner surface 2 a having light reflectivity of the housing 2 surrounds the periphery of the optical semiconductor element 3. The inner surface 2a is formed so that the diameter of the inner surface 2a increases toward the opening end. Therefore, of the light emitted from the optical semiconductor element 3, the light that has reached the inner surface 2 a is reflected by the inner surface 2 a and travels forward of the optical semiconductor element 3. In a region surrounded by the inner surface 2 a so as to seal the optical semiconductor element 3, an optical semiconductor element sealing agent 4 is filled.

  The structure shown in FIG. 1 is merely an example of an optical semiconductor device according to the present invention, and can be appropriately modified to the mounting structure of the optical semiconductor element 3.

  Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to the following examples.

(Synthesis Example 1)
To a 1000 mL separable flask equipped with a thermometer, a dropping device and a stirrer, trimethylmethoxysilane (23 g) dimethyldimethoxysilane (180 g), phenyltrimethoxysilane (100 g), 2- (3,4-epoxycyclohexyl) ethyltri Methoxysilane (100 g) was added and stirred at 50 ° C. Next, an aqueous solution in which 0.7 g of potassium hydroxide was dissolved in 107 g of water was slowly added dropwise, and the reaction was stirred at 50 ° C. for 6 hours. Next, acetic acid (0.8 g) was added to the reaction solution, the pressure was reduced to remove volatile components, and the reaction solution was filtered to remove potassium acetate to obtain a silicone resin (A1). The number average molecular weight (Mn) of the silicone resin (A1) is 2200, and the chemical structure identified from ²⁹ Si-NMR is
(Me ₃ SiO _1/2 ) _0.08 (Me ₂ SiO _2/2 ) _0.58 (PhSiO _3/2 ) _0.19 (EpSiO _3/2 ) _0.15
The ratio of 2- (3,4-epoxycyclohexyl) ethyl group is 19 mol%, the ratio of phenyl group is 15 mol%, and the epoxy equivalent is 691 g / eq. Met.

  The molecular weight was measured by adding tetrahydrofuran (1 mL) to silicone resin (A1) (10 mg) until dissolved, and measuring device manufactured by Waters (column: Shodex GPC LF-804 (length: 300 mm) manufactured by Showa Denko KK) × Measurement was performed by GPC measurement using two tubes, measurement temperature: 40 ° C., flow rate: 1 mL / min, solvent: tetrahydrofuran, standard substance: polystyrene). Moreover, the epoxy equivalent was calculated | required based on JISK-7236.

(Synthesis Example 2)
In a 1000 mL separable flask equipped with a thermometer, a dropping device and a stirrer, trimethylmethoxysilane (25 g), dimethyldimethoxysilane (208 g), diphenyldimethoxysilane (71 g), phenyltrimethoxysilane (58 g), and 2- (3,4-Epoxycyclohexyl) ethyltrimethoxysilane (111 g) was added and stirred at 50 ° C. Next, an aqueous solution in which 0.8 g of potassium hydroxide was dissolved in 117 g of water was slowly added dropwise, and the mixture was reacted by stirring at 50 ° C. for 6 hours. Next, acetic acid (0.9 g) was added to the reaction solution, the pressure was reduced to remove volatile components, and the reaction solution was filtered to remove potassium acetate to obtain a silicone resin (A2). The number average molecular weight (Mn) of the silicone resin (A2) is 1800, and the chemical structure identified from ²⁹ Si-NMR is
(Me ₃ SiO _1/2 ) _0.08 (Me ₂ SiO _2/2 ) _0.57 (Ph ₂ SiO _2/2 ) _0.10 (PhSiO _3/2 ) _0.10 (EpSiO _3/2 ) _{0. 15}
Met. Ep in the above chemical structure represents a 2- (3,4-epoxycyclohexyl) ethyl group. In the silicone resin (A2), the content ratio of 2- (3,4-epoxycyclohexyl) ethyl group is 17 mol%, the content ratio of phenyl group is 21 mol%, and the epoxy equivalent is 723 g / eq. Met.

  The molecular weight and epoxy equivalent were determined in the same manner as in Synthesis Example 1.

(Synthesis Example 3)
In a 1000 mL separable flask equipped with a thermometer, a dropping device and a stirrer, dimethyldimethoxysilane (254 g), diphenyldimethoxysilane (106 g), and 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane (111 g) And stirred at 50 ° C. Next, an aqueous solution in which 0.8 g of potassium hydroxide was dissolved in 116 g of water was slowly added dropwise, and the mixture was reacted by stirring at 50 ° C. for 6 hours. Next, acetic acid (0.9 g) was added to the reaction liquid, the pressure was reduced to remove volatile components, and the reaction liquid was filtered to remove potassium acetate to obtain a silicone resin (A3). The number average molecular weight (Mn) of the silicone resin (A3) is 1600, and the chemical structure identified from ²⁹ Si-NMR is
(Me ₂ SiO _2/2 ) _0.70 (Ph ₂ SiO _2/2 ) _0.15 (EpSiO _3/2 ) _0.15
Met. Ep in the above chemical structure represents a 2- (3,4-epoxycyclohexyl) ethyl group. In the silicone resin (A3), the content ratio of 2- (3,4-epoxycyclohexyl) ethyl group is 17 mol%, the content ratio of phenyl group is 21 mol%, and the epoxy equivalent is 742 g / eq. Met.

  The molecular weight and epoxy equivalent were determined in the same manner as in Synthesis Example 1.

(Synthesis Example 4)
In a 1000 mL separable flask equipped with a thermometer, a dropping device and a stirrer, trimethylmethoxysilane (23 g), dimethyldimethoxysilane (115 g), phenyltrimethoxysilane (71 g), 2- (3,4-epoxycyclohexyl) ethyl Trimethoxysilane (133 g), diphenyldimethoxysilane (88 g), and cyclohexyldimethoxymethylsilane (51 g) were added and stirred at 50 ° C. Next, an aqueous solution in which 0.8 g of potassium hydroxide was dissolved in 117 g of water was slowly added dropwise, and the mixture was reacted by stirring at 50 ° C. for 6 hours. Next, acetic acid (0.8 g) was added to the reaction solution, the pressure was reduced to remove volatile components, and the reaction solution was filtered to remove potassium acetate to obtain a silicone resin (A4). The number average molecular weight (Mn) of the silicone resin (A4) is 1500, and the chemical structure identified from ²⁹ Si-NMR is
(Me ₃ SiO _1/2 ) _0.08 (Me ₂ SiO _2/2 ) _0.41 (PhSiO _3/2 ) _0.13 (EpSiO _3/2 ) _0.15 (Ph ₂ SiO _2/2 ) _{0. 13} (Me (C ₆ H ₁₁ ) SiO _2/2 ) _0.10
Met. Ep in the above chemical structure represents a 2- (3,4-epoxycyclohexyl) ethyl group. In the silicone resin (A4), the content ratio of 2- (3,4-epoxycyclohexyl) ethyl group is 16 mol%, the content ratio of phenyl group is 25 mol%, and the content ratio of cyclohexyl group is 7 mol%. , Epoxy equivalent was 810 g / eq. Met.

  The molecular weight and epoxy equivalent were determined in the same manner as in Synthesis Example 1.

(Synthesis Example 5)
To a 500 ml flask equipped with a stirrer and a condenser, 75 g of phenol resin (BisP-M, manufactured by Honshu Chemical Industry Co., Ltd.), 75 g of phenyltrimethoxysilane, 100 g of methyl ethyl ketone and 0.15 g of dibutyltin dilaurate as a catalyst were added. The demethanol reaction was carried out at 5 ° C. for 5 hours. Next, the pressure was reduced at 80 ° C. to remove volatile components, and a liquid alkoxysilane-modified phenol resin (B1) was obtained.

(Synthesis Example 6)
To a 500 ml flask equipped with a stirrer and a condenser, 100 g of phenol resin (BisP-M, manufactured by Honshu Chemical Industry Co., Ltd.), 50 g of phenyltrimethoxysilane, 100 g of methyl ethyl ketone and 0.15 g of dibutyltin dilaurate as a catalyst were added. The demethanol reaction was carried out at 5 ° C. for 5 hours. Next, the pressure was reduced at 80 ° C. to remove volatile components, and a liquid alkoxysilane-modified phenol resin (B2) was obtained.

(Synthesis Example 7)
To a 500 ml flask equipped with a stirrer and a condenser, 75 g of phenol resin (BisP-M, manufactured by Honshu Chemical Industry Co., Ltd.), 75 g of methyltrimethoxysilane, 100 g of methyl ethyl ketone and 0.15 g of dibutyltin dilaurate as a catalyst were added. Demethanol reaction was carried out at 5 ° C. for 5 hours. Next, the pressure was reduced at 80 ° C. to remove volatile components, and a liquid alkoxysilane-modified phenol resin (B3) was obtained.

(Synthesis Example 8)
To a 500 ml flask equipped with a stirrer and a condenser, 100 g of phenol resin (BisP-M, manufactured by Honshu Chemical Industry Co., Ltd.), 50 g of methyltrimethoxysilane, 100 g of methyl ethyl ketone and 0.15 g of dibutyltin dilaurate as a catalyst were added. Demethanol reaction was carried out at 5 ° C. for 5 hours. Next, the pressure was reduced at 80 ° C. to remove volatile components, and a liquid alkoxysilane-modified phenol resin (B4) was obtained.

(Synthesis Example 9)
To a 500 ml flask equipped with a stirrer and a condenser, 75 g of phenol resin (BisP-M, manufactured by Honshu Chemical Industry Co., Ltd.), 75 g of tetramethoxysilane, 100 g of methyl ethyl ketone and 0.15 g of dibutyltin dilaurate as a catalyst were added, and 100 ° C. For 5 hours. Next, the pressure was reduced at 80 ° C. to remove volatile components, and a liquid alkoxysilane-modified phenol resin (B5) was obtained.

Example 1
70 g of the silicone resin (A1) obtained in Synthesis Example 1, 30 g of the liquid alkoxysilane-modified phenol resin (B1) obtained in Synthesis Example 5, triphenylphosphine (curing accelerator, manufactured by Wako Pure Chemical Industries, Ltd.) 0 0.5 g and 0.1 g of sand stub P-EPQ (antioxidant, manufactured by Clariant) were mixed and defoamed to obtain an encapsulant for optical semiconductor elements.

(Example 2)
Sealed in the same manner as in Example 1 except that the liquid alkoxysilane-modified phenol resin (B1) obtained in Synthesis Example 5 was changed to the liquid alkoxysilane-modified phenol resin (B2) obtained in Synthesis Example 6. An agent was obtained.

(Example 3)
Sealed in the same manner as in Example 1 except that the liquid alkoxysilane-modified phenol resin (B1) obtained in Synthesis Example 5 was changed to the liquid alkoxysilane-modified phenol resin (B3) obtained in Synthesis Example 7. An agent was obtained.

Example 4
Sealed in the same manner as in Example 1 except that the liquid alkoxysilane-modified phenol resin (B1) obtained in Synthesis Example 5 was changed to the liquid alkoxysilane-modified phenol resin (B4) obtained in Synthesis Example 8. An agent was obtained.

(Example 5)
A sealant was obtained in the same manner as in Example 1 except that the silicone resin (A1) obtained in Synthesis Example 1 was changed to the silicone resin (A2) obtained in Synthesis Example 2.

(Example 6)
A sealant was obtained in the same manner as in Example 1 except that the silicone resin (A1) obtained in Synthesis Example 1 was changed to the silicone resin (A3) obtained in Synthesis Example 3.

(Example 7)
A sealant was obtained in the same manner as in Example 1 except that the silicone resin (A1) obtained in Synthesis Example 1 was changed to the silicone resin (A4) obtained in Synthesis Example 4.

(Example 8)
Sealed in the same manner as in Example 1 except that the liquid alkoxysilane-modified phenol resin (B1) obtained in Synthesis Example 5 was changed to the liquid alkoxysilane-modified phenol resin (B5) obtained in Synthesis Example 9. An agent was obtained.

Example 9
Sealant as in Example 1 except that 95 g of the silicone resin (A1) obtained in Synthesis Example 1 and 5 g of the liquid alkoxysilane-modified phenol resin (B1) obtained in Synthesis Example 5 were changed. Got.

(Example 10)
Sealant as in Example 1 except that 30 g of the silicone resin (A1) obtained in Synthesis Example 1 was changed to 70 g of the liquid alkoxysilane-modified phenol resin (B1) obtained in Synthesis Example 5 Got.

(Comparative Example 1)
100 g of the silicone resin (A1) obtained in Synthesis Example 1, 25 g of Ricacid MH-700G (an acid anhydride, manufactured by Shin Nippon Chemical Co., Ltd.) as a curing agent, and U-CATSA 102 (a curing accelerator, manufactured by San Apro) 0 .3 g and 0.1 g of sand stub P-EPQ (antioxidant, manufactured by Clariant) were mixed and defoamed to obtain an encapsulant for optical semiconductor elements.

(Comparative Example 2)
100 g of the silicone resin (A2) obtained in Synthesis Example 2, 25 g of Ricacid MH-700G (an acid anhydride, manufactured by Shin Nippon Chemical Co., Ltd.) as a curing agent, and U-CATSA 102 (a curing accelerator, manufactured by San Apro) 0 .3 g and 0.1 g of sand stub P-EPQ (antioxidant, manufactured by Clariant) were mixed and defoamed to obtain an encapsulant for optical semiconductor elements.

(Comparative Example 3)
Sealant as in Example 1 except that 10 g of the silicone resin (A1) obtained in Synthesis Example 1 was changed to 90 g of the liquid alkoxysilane-modified phenol resin (B1) obtained in Synthesis Example 5 Got.

(Comparative Example 4)
The same procedure as in Example 1 was conducted except that 99.5 g of the silicone resin (A1) obtained in Synthesis Example 1 and 0.5 g of the liquid alkoxysilane-modified phenol resin (B1) obtained in Synthesis Example 5 were changed. To obtain a sealant.

[Evaluation]
(Production of optical semiconductor)
As an optical semiconductor element, an optical semiconductor element composed of an LED chip having a main emission peak of 460 nm was prepared. This optical semiconductor element was mounted on a housing material having a silver-plated lead electrode and made of PPA resin using a die bonding material. The optical semiconductor element and the lead electrode were electrically connected by a gold wire. Into the structure thus obtained, the encapsulant for optical semiconductor elements prepared in Examples 1 to 7 or Comparative Examples 1 and 2 was injected, heated at 100 ° C. for 3 hours, and further heated at 130 ° C. for 3 hours. Then, the encapsulant for optical semiconductor elements was cured. In this way, an optical semiconductor device was obtained.

(Gas corrosion test)
The optical semiconductor device created above was placed in a chamber under an atmosphere of 40 ° C. and 90 RH%. Next, hydrogen sulfide gas and sulfur dioxide gas were introduced into the chamber to adjust the hydrogen sulfide gas concentration to 3 ppm and the sulfur dioxide gas concentration to 10 ppm. One day later, one week later, and two weeks later, the optical semiconductor device was taken out of the chamber, and the silver-plated lead electrode was visually observed. The case where no discoloration is seen in the silver-plated portion, ◎, the case where about 5 to 25% of the total area of the brown-colored portion is observed in the visually observed region is ○, the total area of the brown-colored portion is A case where it exceeded 25% and 75% or less of the visually observed region was evaluated as Δ, and a case where almost all of the visually observed region was changed to black was determined as ×.

  The results are shown in Table 1 below.

DESCRIPTION OF SYMBOLS 1 ... Optical semiconductor device 2 ... Housing 2a ... Inner surface 3 ... Optical semiconductor element 4 ... Sealant for optical semiconductor elements

Claims (5)

Containing a silicone resin having one or more cyclic ether-containing groups in the molecule and a liquid phenolic resin;
The silicone resin includes an resin having an average composition formula represented by the following general formula (1), and a phenyl group content ratio determined by the following formula (a) is 15 to 60 mol%. Sealant.

In the general formula (1), a, b, and c are a / (a + b + c) = 0 to 0.3, b / (a + b + c) = 0.5 to 0.9, and c / (a + b + c) = 0. 1 to 0.4 are satisfied, and at least one of R1 to R6 represents a cyclic ether-containing group and / or a phenyl group, and R ^{1 to} R ⁶ other than the cyclic ether-containing group and the phenyl group are linear or It represents a branched hydrocarbon group having 1 to 8 carbon atoms or a linear or branched hydrocarbon group having 1 to 8 carbon atoms.
R ^{1 to} R ⁶ may be the same or different.
Phenyl group content ratio (mol%) = (average number of phenyl groups contained in one molecule of resin whose average composition formula is represented by general formula (1) × molecular weight of phenyl group / average composition formula is general formula ( 1) Average molecular weight of the resin component represented by 1) × 100 Formula (a)   The encapsulant for optical semiconductor elements according to claim 1, wherein the liquid phenolic resin is an alkoxysilane-modified phenolic resin produced by reacting a silicon compound having an alkoxy group with a phenolic resin.   The encapsulant for optical semiconductor elements according to claim 2, wherein the silicon compound having an alkoxy group is a trialkoxysilane compound or a tetraalkoxysilane compound.   The encapsulant for optical semiconductor elements according to claim 3, wherein the alkoxysilane compound has a phenyl group.   An optical semiconductor device comprising: an optical semiconductor element; and the encapsulant for an optical semiconductor element according to claim 1 or 2 provided to seal the optical semiconductor element.

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