Resin composition for optical semiconductor encapsulation, resin molded product for optical semiconductor encapsulation, optical semiconductor encapsulant, and optical semiconductor device

Abstract

To provide an optical semiconductor sealing resin composition which compatibly has UV transmission and heat resistance properties, an optical semiconductor sealing resin molding using the same, an optical semiconductor sealing material, and an optical semiconductor device.SOLUTION: X=(A1×A2) / A3+(B1×B2) / B3+ ...<0.0005 (expression 1) holds, where A1 represents a mass ratio of an aromatic compound, A2 represents the number of aromatic rings included in one molecule of an aromatic compound, and A3 represents a molecular weight of the aromatic compound. Further, A, B ... represent aromatic compounds. An optical semiconductor sealing resin composition has a linear transmittance of 80% or larger at a wavelength of 300 nm and 95% or larger at 400 nm when being a hardened body of 50 mm in width, 50 mm in length, and 1 mm in thickness which satisfies the expression 1 and contains epoxy, alicyclic acid anhydride, and an antioxidant.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a resin composition for encapsulating an optical semiconductor, a resin molded product for encapsulating an optical semiconductor, an optical semiconductor encapsulant, and an optical semiconductor device.

Background Art

[0002] Optical semiconductor elements are encapsulated and made into devices using ceramic packages or plastic packages. Here, since ceramic packages are relatively expensive in terms of constituent materials and are inferior in mass productivity, the use of plastic packages has become mainstream. Among these, in terms of workability, mass productivity, and reliability, the technology of transfer molding an epoxy resin composition that has been pre-compacted into a tablet shape has become mainstream.

[0003] Optical semiconductors are widely used depending on the application up to the ultraviolet (UV) to infrared light (IR) region, and the light transmittance and light resistance required for the optical semiconductor encapsulating resin differ depending on the wavelength. For example, Patent Document 1 discloses that by blending a specific silicone resin, good light resistance can be obtained even for light with a short wavelength (for example, 350 to 500 nm).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As a result of intensive studies by the present inventors, it has been found that there is room for improvement in UV transparency in the technology described in Patent Document 1. Regarding this point, as a result of further intensive studies by the present inventors, particularly with respect to a resin for encapsulating an optical semiconductor in a shorter wavelength region (for example, UV-B of 280 to 315 nm), when an organic material is used, there is a possibility that the light emitting function of the LED may be impaired due to light absorption of the resin for encapsulating an optical semiconductor, and it has been found that there is room for improvement in UV transparency. And in order to ensure UV transparency, it is necessary to exclude raw materials having light absorption in the UV region having an aromatic ring such as an antioxidant (materials having an aromatic ring), but in this case, it has been newly found that there is a problem that it is difficult to achieve high functionality such as heat resistance. The present invention solves the above-mentioned problems newly found by the present inventors, and an object thereof is to provide a resin composition for encapsulating an optical semiconductor that achieves both UV transparency and heat resistance, and a resin molded product for encapsulating an optical semiconductor, an optical semiconductor encapsulant, and an optical semiconductor device using the same.

Means for Solving the Problems

[0006] The present invention relates to X = (A1 × A2) / A3 + (B1 × B2) / B3 + ··· < 0.0005 ··· (Formula 1) (In (Formula 1), A1 represents the mass ratio of the aromatic compound, A2 represents the number of aromatic rings contained in one molecule of the aromatic compound, and A3 represents the molecular weight of the aromatic compound. A, B ··· represent aromatic compounds.) The present invention relates to a resin composition for encapsulating an optical semiconductor that satisfies the above (Formula 1), contains an epoxy, an alicyclic acid anhydride, and an antioxidant, and has a linear transmittance of 80% or more at a wavelength of 300 nm and a linear transmittance of 95% or more at a wavelength of 400 nm when formed into a cured product (size: width 50 mm × length 50 mm × thickness 1 mm) by the following method. (Method for Producing Cured Product) The resin composition is heated and molded at 150°C for 4 minutes, and then heated at 150°C for 3 hours to obtain a cured product.

[0007] It is preferable that the epoxy is a compound having a non-aromatic ring structure.

[0008] The resin composition for optical semiconductor encapsulation preferably contains a release agent.

[0009] The release agent is a release agent having a molecular structure having a structural unit represented by the following structural formula (2) and a structural unit represented by structural formula (3), It is preferable that the proportion of the structural unit represented by the structural formula (3) is set to 25 to 95% by mass of the entire molecular structure constituting the release agent.

Chemical formula

Chemical formula

[0010] It is preferable that the antioxidant is a compound having a phosphite structure.

[0011] The resin composition for optical semiconductor encapsulation is preferably for a light-emitting diode, and more preferably for a UV-B light-emitting diode.

[0012] The present invention also relates to a resin molded article for optical semiconductor encapsulation containing the resin composition for optical semiconductor encapsulation.

[0013] The present invention also relates to an optical semiconductor encapsulant obtained by molding the resin molded article for optical semiconductor encapsulation.

[0014] The present invention also relates to an optical semiconductor device including an optical semiconductor element and the optical semiconductor encapsulant for encapsulating the optical semiconductor element.

[0015] In the optical semiconductor device, it is preferable that the optical semiconductor element is a light-emitting diode, and more preferably a UV-B light-emitting diode.

Advantages of the Invention

[0016] The resin composition for encapsulating an optical semiconductor of the present invention satisfies the above (Formula 1), contains an epoxy, an alicyclic acid anhydride, and an antioxidant, and when formed into a cured body (size: width 50 mm × length 50 mm × thickness 1 mm) by the above method, the linear transmittance at a wavelength of 300 nm is 80% or more, and the linear transmittance at a wavelength of 400 nm is 95% or more. Therefore, both UV transmittance and heat resistance can be achieved.

Embodiments for Carrying Out the Invention

[0017] The resin composition for encapsulating an optical semiconductor of the present invention satisfies X = (A1 × A2) / A3 + (B1 × B2) / B3 + ··· < 0.0005 ··· (Formula 1) (In (Formula 1), A1 represents the mass ratio of the aromatic compound, A2 represents the number of aromatic rings contained in one molecule of the aromatic compound, and A3 represents the molecular weight of the aromatic compound. A, B ··· represent aromatic compounds.) Satisfying the above (Formula 1), containing an epoxy, an alicyclic acid anhydride, and an antioxidant, and when formed into a cured body (size: width 50 mm × length 50 mm × thickness 1 mm) by the following method, the linear transmittance at a wavelength of 300 nm is 80% or more, and the linear transmittance at a wavelength of 400 nm is 95% or more. (Method for Producing the Cured Body) The resin composition is heated and molded at 150°C for 4 minutes, and then heated at 150°C for 3 hours to obtain a cured body. Thereby, both UV transmittance and heat resistance can be achieved.

[0018] The reason why the above-described effects are obtained with the above composition is presumed as follows. X in the above (Formula 1) represents the number of aromatic rings (pieces / g) in 1 g of the resin composition for encapsulating an optical semiconductor. Satisfying the above (Formula 1) means that the number of aromatic rings in the composition is small, and when formed into a cured body by the above method, the linear transmittance at a wavelength of 300 nm is 80% or more, and the linear transmittance at a wavelength of 400 nm is 95% or more. Therefore, good UV transmittance can be obtained. Furthermore, by containing an epoxy, an alicyclic acid anhydride, and an antioxidant while satisfying the above requirements, good heat resistance can be obtained together with good UV transmittance. Thus, while containing epoxy, alicyclic acid anhydride, and an antioxidant, satisfying the above (Formula 1), and forming a cured product by the above method, since the linear transmittance at a wavelength of 300 nm is 80% or more and the linear transmittance at a wavelength of 400 nm is 95% or more, both UV transparency and heat resistance can be achieved.

[0019] <Resin composition for optical semiconductor encapsulation> The resin composition for optical semiconductor encapsulation of the present invention satisfies the following (Formula 1). X = (A1 × A2) / A3 + (B1 × B2) / B3 + ··· < 0.0005 ···(Formula 1) ((In Formula 1, A1 represents the mass ratio of the aromatic compound, A2 represents the number of aromatic rings contained in one molecule of the aromatic compound, and A3 represents the molecular weight of the aromatic compound. A, B ··· represent aromatic compounds.))

[0020] A1 represents the mass ratio of the aromatic compound, that is, the mass ratio of the aromatic compound A in the composition. For example, when 1 part by mass of the aromatic compound A is contained in 100 parts by mass of the composition, it is 1 / 100 = 0.01. A2 represents the number of aromatic rings contained in one molecule of the aromatic compound, that is, the number of aromatic rings contained in one molecule of the aromatic compound A. A3 represents the molecular weight of the aromatic compound, that is, the molecular weight of the aromatic compound A. A, B ··· represent aromatic compounds. By calculating (A1 × A2) / A3 for each type of aromatic compound and adding up the calculation results for all aromatic compounds, X is calculated.

[0021] X is less than 0.0005, preferably 0.0004 or less, and the lower limit is not particularly limited because the smaller the value, the more preferable.

[0022] The resin composition for optical semiconductor encapsulation of the present invention has a linear transmittance of 80% or more at a wavelength of 300 nm and a linear transmittance of 95% or more at a wavelength of 400 nm when formed into a cured product by the above method. In order to prepare such a composition, the composition may be prepared according to the following guidelines. (1) Use a compound with few aromatic rings. This is because aromatic rings have strong light absorption at 250 nm to 320 nm. (2) Even when using a compound having an aromatic ring, use a compound having no conjugated structure. This is because a compound having an aromatic ring and a conjugated structure has strong light absorption at 280 nm to 320 nm, while a compound having an aromatic ring but no conjugated structure has almost no light absorption over the range of 280 nm to 400 nm. (3) Use a compound having cyclohexane. This is because a compound having cyclohexane has almost no light absorption over the range of 280 nm to 400 nm.

[0023] The resin composition for encapsulating an optical semiconductor of the present invention contains epoxy (epoxy resin), alicyclic anhydride, and an antioxidant.

[0024] <<Thermosetting resin>> As the epoxy resin, those with less coloring are preferred. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resin, triglycidyl isocyanurate, heterocyclic ring-containing epoxy resins such as hydantoin epoxy, water-added bisphenol A type epoxy resin, aliphatic epoxy resin, glycidyl ether type epoxy resin, cresol novolac type epoxy resin, etc. can be mentioned. These can be used alone or in combination of two or more. Among them, it is preferably a compound (epoxy resin) having a non-aromatic ring structure, and more preferably a compound having no aromatic ring. This is because when an epoxy resin having an aromatic ring such as bisphenol A type epoxy resin is used, it satisfies the above (Formula 1), and when it is made into a cured product by the above method, the linear transmittance at a wavelength of 300 nm is 80% or more, and the linear transmittance at a wavelength of 400 nm is 95% or more. It becomes difficult, and there is a possibility of inferior UV transmittance. However, by using a compound having a non-aromatic ring structure as the epoxy resin, it satisfies the above (Formula 1), and when it is made into a cured product by the above method, the linear transmittance at a wavelength of 300 nm is 80% or more, and the linear transmittance at a wavelength of 400 nm is 95% or more. It becomes easier, and the UV transmittance becomes more excellent. Furthermore, better heat resistance can also be obtained.

[0025] The non-aromatic ring structure is not particularly limited as long as it is a saturated or unsaturated ring structure (preferably having no unsaturated bond in the ring) that does not have aromaticity. For example, non-aromatic heterocyclic ring structures, alicyclic ring structures, etc. can be mentioned. Among them, non-aromatic heterocyclic ring structures are preferred. In this specification, the non-aromatic heterocyclic ring structure means a ring structure composed of atoms other than carbon atoms and carbon atoms, which is a saturated or unsaturated (preferably having no unsaturated bond in the ring) ring structure that does not have aromaticity. In this specification, the alicyclic ring structure means a saturated or unsaturated carbon ring (preferably a carbon ring having no unsaturated bond in the ring) structure that does not have aromaticity.

[0026] The ring member number of the non-aromatic ring is not particularly limited, but is preferably 3 or more, more preferably 4 or more, still more preferably 5 or more, and preferably 13 or less, more preferably 10 or less, still more preferably 7 or less. Within the above range, there is a tendency that UV transparency and heat resistance can be more compatible.

[0027] The non-aromatic ring may be a monocyclic ring, a polycyclic ring, or may have a bridged structure. Among them, a monocyclic ring is preferred.

[0028] The atoms other than carbon atoms in the non-aromatic heterocyclic ring are not particularly limited, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, a boron atom, a silicon atom, a phosphorus atom, and the like. These can be used alone or in combination of two or more. Among them, an oxygen atom, a nitrogen atom, and a sulfur atom are preferred, an oxygen atom and a nitrogen atom are more preferred, and a nitrogen atom is still more preferred.

[0029] The number of atoms other than carbon atoms in the non-aromatic heterocyclic ring is not particularly limited, but is preferably 1 or more, more preferably 2 or more, and preferably 5 or less, more preferably 4 or less. Within the above range, there is a tendency that UV transparency and heat resistance can be more compatible.

[0030] As the compound having a non-aromatic ring structure, it only needs to have a non-aromatic ring structure, and may have a plurality of non-aromatic ring structures in the molecule. The compound having a non-aromatic ring structure preferably does not have an aromatic ring.

[0031] Examples of the compound (epoxy resin) having a non-aromatic ring structure include, but are not particularly limited to, water-added bisphenol A type epoxy resin, water-added bisphenol F type epoxy resin, water-added phenol novolac type epoxy resin, water-added cresol novolac type epoxy resin, alicyclic epoxy resin, triglycidyl isocyanurate, hydantoin epoxy, 3,4-epoxycyclohexanecarboxylate, and 1,2-epoxy-4-(2-oxiranyl) cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol. These can be used alone or in combination of two or more. Among them, triglycidyl isocyanurate, 3,4-epoxycyclohexanecarboxylate, and 1,2-epoxy-4-(2-oxiranyl) cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol are preferred, and triglycidyl isocyanurate is more preferred.

[0032] In 100% by mass of the epoxy resin, the proportion of the epoxy resin having a non-aromatic ring structure (preferably triglycidyl isocyanurate) is preferably 40% by mass or more, more preferably 60% by mass or more, still more preferably 80% by mass or more, particularly preferably 90% by mass or more, most preferably 95% by mass or more, and may be 100% by mass. When within the above range, there is a tendency to better balance UV transmittance and heat resistance.

[0033] The resin composition for encapsulating an optical semiconductor of the present invention may contain a thermosetting resin other than the epoxy resin.

[0034] In 100% by mass of the thermosetting resin, the proportion of the epoxy resin is preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 30% by mass or more, particularly preferably 60% by mass or more, most preferably 80% by mass or more, even most preferably 90% by mass or more, and may be 100% by mass. When within the above range, there is a tendency to better balance UV transmittance and heat resistance.

[0035] <<Hardener>> The resin composition for encapsulating an optical semiconductor of the present invention contains an alicyclic acid anhydride as a curing agent. By containing an alicyclic acid anhydride as a curing agent, the formula (1) is satisfied, and when it is made into a cured body by the above method, the linear transmittance at a wavelength of 300 nm is 80% or more, and the linear transmittance at a wavelength of 400 nm is 95% or more, which becomes easier, and the UV transmittance is more excellent. Furthermore, better heat resistance can also be obtained. In the present specification, the alicyclic acid anhydride means a compound having an anhydride group (preferably a carboxylic acid anhydride group) and an alicyclic structure. The curing agent can be used alone or in combination of two or more.

[0036] Examples of the alicyclic acid anhydride include alicyclic polyvalent carboxylic acid anhydrides such as hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylnadic anhydride, nadic anhydride, methylhexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, dimethyltetrahydrophthalic anhydride, norbornene dicarboxylic anhydride, methylbicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride, bicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride, bicyclo[2.2.1]hepta-5-ene-2,3-dicarboxylic anhydride, methylbicyclo[2.2.1]hepta-5-ene-2,3-dicarboxylic anhydride, and cyclopentane tetracarboxylic anhydride. These can be used alone or in combination of two or more. Among them, hexahydrophthalic anhydride and methylhexahydrophthalic anhydride are preferable, and hexahydrophthalic anhydride is more preferable.

[0037] The blending amount of the alicyclic acid anhydride is preferably 20 to 200 parts by mass, more preferably 60 to 180 parts by mass, and further preferably 100 parts by mass or more with respect to 100 parts by mass of the epoxy resin. If it is less than 20 parts by mass, the curing rate becomes slow, and if it exceeds 200 parts by mass, there is an excessive amount with respect to the curing reaction, which may cause deterioration of various physical properties.

[0038] The resin composition for encapsulating an optical semiconductor of the present invention may contain a curing agent other than the alicyclic acid anhydride. Examples of hardeners other than alicyclic acid anhydrides include acid anhydride-based hardeners other than alicyclic acid anhydrides such as chain polycarboxylic acid anhydrides and aromatic polycarboxylic acid anhydrides; phenolic hardeners; amine-based hardeners and the like. These may be used alone or in combination of two or more.

[0039] In 100% by mass of the hardener, the proportion of the alicyclic acid anhydride is preferably 60% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and may be 100% by mass. When within the above range, there is a tendency that UV transparency and heat resistance can be better balanced.

[0040] <<Antioxidant>> The resin composition for optical semiconductor encapsulation of the present invention contains an antioxidant. Thereby, good heat resistance can be obtained. The antioxidant can be used alone or in combination of two or more. Among antioxidants, there are primary antioxidants that scavenge radicals generated when a bond is broken and secondary antioxidants that decompose oxides, and it is preferable to use both in combination. Thereby, better heat resistance can be obtained.

[0041] Examples of the primary antioxidant include hindered phenol-based compounds and the like. These can be used alone or in combination of two or more. Among them, hindered phenol-based compounds are preferable because good heat resistance can be obtained.

[0042] Examples of the hindered phenol compounds include 2,6-di-tert-butyl-p-cresol, pentaerythrityl-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tris-(3,5-di-tert-butyl-4-hydroxybenzyl)-isocyanurate, and the like. These can be used alone or in combination of two or more. Among them, 2,6-di-tert-butyl-p-cresol and pentaerythrityl-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] are preferable because good heat resistance can be obtained, and 2,6-di-tert-butyl-p-cresol is more preferable.

[0043] The compounding amount of the primary antioxidant is preferably 0.5 to 20 parts by mass, more preferably 0.5 to 15 parts by mass, still more preferably 0.5 to 5 parts by mass, and particularly preferably 0.5 to 3 parts by mass with respect to 100 parts by mass of the epoxy resin. If it is less than 0.5 part by mass, the heat resistance may decrease, and if it exceeds 20 parts by mass, the UV transmittance may decrease.

[0044] Examples of the secondary antioxidant include compounds having a phosphite ester structure, sulfur compounds, and the like. These can be used alone or in combination of two or more. Among them, compounds having a phosphite ester structure (phosphite ester compounds) are preferable because good heat resistance and good UV transmittance can be obtained.

[0045] Generally used antioxidants have an aromatic ring and a conjugated structure, so they have a large light absorption at 280 nm to 320 nm. However, although phosphite compounds have an aromatic ring, they do not have a conjugated structure, so they have almost no light absorption over the range of 280 nm to 400 nm. Therefore, by blending a phosphite compound, good heat resistance can be obtained, and when it is made into a cured product by the above method, the linear transmittance at a wavelength of 300 nm is 80% or more, and the linear transmittance at a wavelength of 400 nm is 95% or more, which becomes easier, and the UV transmittance is more excellent.

[0046] Examples of the phosphite compound include triphenyl phosphite, tris(nonylphenyl) phosphite, tricresyl phosphite, triethyl phosphite, tris(2-ethylhexyl) phosphite, tridecyl phosphite, trilauryl phosphite, tris(tridecyl) phosphite, trioleyl phosphite, diphenylmono(2-ethylhexyl) phosphite, diphenylmonodecyl phosphite, diphenylmono(tridecyl) phosphite, trilauryl thiophosphite, bis(decyl)pentaerythritol diphosphite, tristearyl phosphite, distearylpentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, and the like. These can be used alone or in combination of two or more. Among them, triphenyl phosphite is preferred because good heat resistance can be obtained and good UV transmittance can also be obtained.

[0047] The blending amount of the secondary antioxidant is preferably 0.5 to 17 parts by mass, more preferably 0.5 to 13 parts by mass, and even more preferably 1 to 10 parts by mass with respect to 100 parts by mass of the epoxy resin. If it is less than 0.5 part by mass, the heat resistance may decrease, and if it exceeds 17 parts by mass, the UV transmittance may decrease.

[0048] <<Polyhydric alcohol>> The resin composition for encapsulating an optical semiconductor of the present invention preferably contains a polyhydric alcohol. Thereby, the glass transition temperature is adjusted, and there is a tendency that UV transmittance and heat resistance can be more compatible. The polyhydric alcohol can be used alone or in combination of two or more.

[0049] The polyhydric alcohol may be a compound having two or more hydroxyl groups, but is preferably a diol (glycol).

[0050] Examples of the polyhydric alcohol include diols having preferably 2 to 10 carbon atoms, more preferably 2 to 6 carbon atoms, and even more preferably 2 to 5 carbon atoms. Examples of the diol include ethylene glycol, propylene glycol, neopentyl glycol, pentanediol, butanediol, etc. Among them, neopentyl glycol is preferable. Examples of the polyhydric alcohol also include polyalkylene glycols such as polyethylene glycol and polypropylene glycol. Among them, polyethylene glycol is preferable. It is also preferable to use the diol having the above carbon number and polyalkylene glycol in combination.

[0051] The blending amount of the polyhydric alcohol is preferably 10 to 60 parts by mass, more preferably 10 to 50 parts by mass, and even more preferably 10 to 40 parts by mass with respect to 100 parts by mass of the epoxy resin. Within the above range, there is a tendency that UV transmittance and heat resistance can be more compatible. As the blending amount of the polyhydric alcohol decreases, the Tg increases accordingly, and there is a tendency that better heat resistance can be obtained.

[0052] <<Release agent>> The resin composition for encapsulating an optical semiconductor of the present invention preferably contains a release agent. Thereby, the moldability is improved, and there is a tendency that UV transmittance and heat resistance can be more compatible. The release agent can be used alone or in combination of two or more.

[0053] Examples of the release agent include a release agent having an ether bond, a fluorine-based release agent, a silicone-based release agent, etc. These can be used alone or in combination of two or more. Among them, a release agent having an ether bond is preferable from the viewpoint of compatibility.

[0054] As the release agent having an ether bond, for example, a release agent (block polymer) having a molecular structure including a structural unit represented by the following structural formula (2) and a structural unit represented by the following structural formula (3) is preferable. A release agent having a molecular structure including a structural unit represented by the following structural formula (2) and a structural unit represented by the following structural formula (3), and in which the proportion of the structural unit represented by the structural formula (3) is set to 25 to 95% by mass of the entire molecular structure constituting the release agent is more preferable. In addition, the bond at the terminal portion of the structural units represented by the formulas (2) and (3) is bonded to a hydrogen atom.

Chemical formula

Chemical formula

[0055] The repeating number m in the structural unit represented by the structural formula (2) is a positive number from 8 to 100, and the proportion occupied by the structural unit represented by the structural formula (3) is set in the range of 25 to 95% by mass of the entire molecular structure constituting the release agent. More preferably, the repeating number m in the structural unit represented by the structural formula (2) is a positive number from 13 to 60, and the proportion occupied by the structural unit represented by the structural formula (3) is in the range of 35 to 85% by mass of the entire molecular structure constituting the release agent. Particularly preferably, the repeating number m in the structural unit represented by the structural formula (2) is a positive number from 17 to 40, and the proportion occupied by the structural unit represented by the structural formula (3) is in the range of 40 to 70% by mass of the entire molecular structure constituting the release agent. Also, the structural unit represented by the structural formula (2) and the structural unit represented by the structural formula (3) may be present continuously in the molecular structure or may be present discontinuously such as randomly, and the form of their existence is not particularly limited, but a continuously present form, so-called block form, is preferable. Furthermore, the structural unit represented by the structural formula (2) and the structural unit represented by the structural formula (3) may each exist not only in one but in a plurality in the molecular structure.

[0056] As units constituting the release agent, in addition to the structural unit represented by the structural formula (2) and the structural unit represented by the structural formula (3), an alkyl group, an alkylene group, a carboxyl group, an ester bond, a ketone bond, a benzene ring, a hydrogen atom, a metal atom, etc. can be mentioned. However, in the specific release agent, the proportion occupied by the structural unit represented by the structural formula (2) and the structural unit represented by the structural formula (3) in the entire molecular structure is usually preferably 70 to 99% by mass.

[0057] The number average molecular weight of the release agent is usually preferably from 300 to 12000, more preferably from 600 to 5000, and particularly preferably from 900 to 2500. The number average molecular weight is a value measured by gel permeation chromatography (GPC) and determined by polystyrene conversion. Also, as a method for specifying the molecular structure of the release agent, the following method can be mentioned. That is, 1By using 1H-NMR, the ratio of each structural unit is determined from the integrated spectrum ratio of the hydrogen bonded to the carbon having an adjacent oxygen [-(CH2CH2O)-] and the hydrogen bonded to the carbon sandwiched between carbons [-(CH2CH2)-], and it can be specified by calculating the number of repetitions from the value of the molecular weight.

[0058] The compounding amount of the release agent is preferably 0.5 to 20 parts by mass, more preferably 5 to 20 parts by mass, and even more preferably 5 to 15 parts by mass with respect to 100 parts by mass of the epoxy resin. When it is within the above range, there is a tendency that UV transparency and heat resistance can be better balanced.

[0059] <<Curing accelerator>> The resin composition for sealing an optical semiconductor of the present invention preferably contains a curing accelerator. Thereby, there is a tendency that UV transparency and heat resistance can be better balanced. The curing accelerator can be used alone or in combination of two or more.

[0060] Examples of the curing accelerator include tertiary amines such as triethanolamine; imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole, and 2-methyl-4-methylimidazole; organic phosphorus compounds such as tributyl(methyl)phosphonium dimethyl phosphate, tetraphenylphosphonium·tetraphenylborate, and triphenylphosphine; diazabicycloalkene compounds such as 1,8-diazabicyclo[5,4,0]undecene-7 and 1,5-diazabicyclo[4,3,0]nonene-5; and the like. These may be used alone or in combination of two or more. Among them, compounds having no aromatic ring are preferred, organic phosphorus compounds are more preferred, and tributyl(methyl)phosphonium dimethyl phosphate is even more preferred.

[0061] The blending amount of the curing accelerator is not particularly limited, but it can be appropriately selected, for example, from the range of 0.1 to 5 parts by mass, preferably 0.5 to 3 parts by mass, and more preferably 1 to 2 parts by mass, based on 100 parts by mass of the epoxy resin. If the blending amount of the curing accelerator is too small, the curing rate will be slow, resulting in a decrease in productivity. On the other hand, if the blending amount of the curing accelerator is too large, the rate of the curing reaction will be fast, making it difficult to control the reaction state and possibly causing variations in the reaction.

[0062] <<Other Additives>> In addition to the above components, additives such as lubricants, phosphors that change the wavelength of light, and inorganic and organic fillers that scatter light can be used as needed in the resin composition for encapsulating an optical semiconductor of the present invention. These additives can be used alone or in combination of two or more.

[0063] Examples of the lubricant include waxes such as stearic acid, magnesium stearate, and calcium stearate, and talc. When the lubricant is blended, its blending amount is appropriately set according to the tableting molding conditions. For example, it is preferably set to 0.1 to 0.4% by mass of the entire resin composition.

[0064] Examples of the phosphor that changes the wavelength of light and the inorganic and organic fillers that scatter light include silica powders such as quartz glass powder, talc, fused silica powder, and crystalline silica powder, alumina, silicon nitride, aluminum nitride, and silicon carbide. These can be used alone or in combination of two or more. When the phosphor or the inorganic and organic fillers are blended, their blending amounts are appropriately set according to the molding conditions. Specifically, in the case of the phosphor, the blending amount of the phosphor can be appropriately set from the range of 1% to 60% by mass of the entire resin composition. On the other hand, in the case of the filler (organic or inorganic) that scatters light, the filler that scatters light can be appropriately set from 0.5% to 25% by mass of the entire resin molded product.

[0065] <<Reactants>> The resin composition for encapsulating an optical semiconductor of the present invention may contain reactants of each compounding agent such as reactants of the thermosetting resin and the curing agent.

[0066] <Method of producing optical semiconductor encapsulating resin composition> The method for producing the optical semiconductor encapsulating resin composition of the present invention is not particularly limited as long as it is a method capable of kneading and dispersing the above-mentioned components, but it is preferable to heat treat the composition to give a B-stage state (semi-cured state).

[0067] The method for producing the optical semiconductor encapsulating resin composition of the present invention includes, for example, A step of kneading a thermosetting resin, a curing agent, and a curing accelerator to obtain a curable resin composition; a step of heat treating the curable resin composition; The manufacturing method includes the steps of:

[0068] The kneading method is not particularly limited, but may be, for example, a method using an extruder. The kneading temperature is also not particularly limited, and may be appropriately changed depending on the characteristics of the thermosetting resin. It is also possible to set the temperature high so as to advance the reaction during kneading. Specifically, the temperature is preferably 80 to 150°C, more preferably 110 to 130°C.

[0069] The shape of the curable resin composition obtained by kneading is not particularly limited, and examples of the shape include a film, a sheet, particles, and a block.

[0070] The thickness of the curable resin composition obtained by kneading is not particularly limited, but is preferably 1 to 30 mm, more preferably 2 to 20 mm, and even more preferably 2 to 10 mm. If the thickness is less than 1 mm, the composition is thin and easily affected by moisture absorption, whereas if the thickness exceeds 30 mm, it takes a long time to cool and the reaction tends to vary due to internal heat accumulation.

[0071] The curable resin composition obtained by kneading is heat-treated to obtain a resin composition for optical semiconductor encapsulation in a B-stage (semi-cured state). The heat treatment temperature is not particularly limited, but is preferably 25 to 100 °C, more preferably 60 to 80 °C. If it is less than 25 °C, the curing reaction is slow and the productivity tends to decrease. If it exceeds 100 °C, the curing reaction is fast and it tends to be difficult to end in a predetermined reaction state. The heat treatment time is not particularly limited and can be appropriately changed according to the properties of the thermosetting resin.

[0072] It is preferable to subject the resin composition for optical semiconductor encapsulation in the B-stage (semi-cured state) obtained by heat treatment to the following steps. A step of pulverizing and / or granulating the heat-treated curable resin composition (resin composition for optical semiconductor encapsulation in a B-stage (semi-cured state)) to obtain a granular curable resin composition

[0073] When pulverizing, the heat-treated resin composition is pulverized to obtain a granular resin composition. Pulverization may be performed using a ball mill, a turbo mill, or the like.

[0074] When granulating, the heat-treated resin composition is granulated to obtain a granular resin composition. Before granulation, it can also be pulverized using a ball mill, a turbo mill, or the like. The granulation method is not particularly limited, and examples include a method using a dry compression granulator.

[0075] The average particle size of the granules obtained by pulverizing and / or granulating is not particularly limited, but is preferably 1 to 5000 μm, more preferably 100 to 2000 μm. If it exceeds 5000 μm, the compression ratio tends to decrease.

[0076] The step of obtaining the granular curable resin composition is preferably a step of granulating the heat-treated curable resin composition (resin composition for optical semiconductor encapsulation in a B-stage (semi-cured state)) to obtain a granular curable resin composition.

[0077] The resin composition for encapsulating an optical semiconductor of the present invention obtained by the above production method or the like has a linear transmittance of 80% or more at a wavelength of 300 nm and a linear transmittance of 95% or more at a wavelength of 400 nm when formed into a cured body (size: width 50 mm × length 50 mm × thickness 1 mm). (Method for producing a cured body) The resin composition is heated and molded at 150°C for 4 minutes, and then heated at 150°C for 3 hours to obtain a cured body.

[0078] The linear transmittance at a wavelength of 300 nm is 80% or more, preferably 81% or more, more preferably 83% or more, still more preferably 85% or more, and the upper limit is not particularly limited. Thereby, light near a wavelength of 300 nm can be suitably transmitted, and the luminous efficiency of the light emitting element can be improved.

[0079] The linear transmittance at a wavelength of 400 nm is 95% or more, preferably 96% or more, more preferably 97% or more, still more preferably 98% or more, and the upper limit is not particularly limited. Thereby, light near a wavelength of 400 nm can be suitably transmitted, and the luminous efficiency of the light emitting element can be improved.

[0080] The linear transmittance is determined by measuring the transmittance spectrum of the cured body at a wavelength of 300 nm or 400 nm using a spectrophotometer. The measurement of the transmittance spectrum is performed in a direction perpendicular to the bottom surface (or top surface) of the sample.

[0081] <Resin molded product for encapsulating an optical semiconductor> Examples of the resin molded product for encapsulating an optical semiconductor of the present invention include tablets and sheets. By molding so as to cover the optical semiconductor element constituting the optical semiconductor device, the element can be encapsulated.

[0082] When the resin molded product for encapsulating an optical semiconductor is a tablet, its volume is not particularly limited, but is preferably 1 to 100 cm 3 and more preferably 10 to 100 cm 3 is more preferable.

[0083] The manufacturing method of the resin molded product for optical semiconductor encapsulation of the present invention, for example, in addition to the above steps, a step of molding the granular resin composition obtained by the step of obtaining the granular curable resin composition is included.

[0084] The resin composition for optical semiconductor encapsulation of the present invention is molded to obtain the resin molded product for optical semiconductor encapsulation of the present invention. Thereby, a resin molded product for optical semiconductor encapsulation containing the resin composition for optical semiconductor encapsulation is obtained. Examples of the molded product include tablets and sheets, and examples of the molding method include tableting for obtaining tablets and extrusion molding for obtaining sheets. The obtained molded product is a high-quality molded product with both UV transparency and heat resistance.

[0085] The resin composition for optical semiconductor encapsulation is molded to obtain the resin molded product for optical semiconductor encapsulation, and the compositions of the resin composition for optical semiconductor encapsulation and the resin molded product for optical semiconductor encapsulation are substantially the same.

[0086] When the molded product is a tablet, the conditions for tableting the tablet are appropriately adjusted according to the composition of the resin composition for optical semiconductor encapsulation, etc. Generally, the compression ratio during the tableting is preferably set to 90 - 96%. That is, if the value of the compression ratio is less than 90%, the density of the tablet may be low and it may be prone to cracking. Conversely, if the value of the compression ratio is greater than 96%, cracks may occur during tableting and chipping or breakage may occur during demolding.

[0087] <Optical semiconductor encapsulant, optical semiconductor device> The resin molded product for optical semiconductor encapsulation of the present invention seals an optical semiconductor element by a molding method such as transfer molding to produce an optical semiconductor device. That is, the resin molded product for optical semiconductor encapsulation of the present invention serves as an optical semiconductor encapsulant that resin-seals an optical semiconductor element by molding such as transfer molding. Thus, the optical semiconductor encapsulant of the present invention is obtained by molding the resin molded product for optical semiconductor encapsulation of the present invention. In this specification, the optical semiconductor encapsulant is a member formed to cover the optical semiconductor element constituting the optical semiconductor device and seals the element.

[0088] Since the resin composition for optical semiconductor encapsulation and the resin molded product for optical semiconductor encapsulation of the present invention can achieve both UV transmittance and heat resistance, the optical semiconductor encapsulant obtained by molding the resin composition for optical semiconductor encapsulation and the resin molded product for optical semiconductor encapsulation of the present invention is a high-quality optical semiconductor encapsulant capable of achieving both UV transmittance and heat resistance.

[0089] The optical semiconductor device of the present invention includes an optical semiconductor element and the optical semiconductor encapsulant of the present invention that encapsulates the optical semiconductor element. Since the optical semiconductor device of the present invention includes the optical semiconductor encapsulant of the present invention, it is a high-quality optical semiconductor device capable of achieving both UV transmittance and heat resistance.

[0090] The resin composition for optical semiconductor encapsulation and the resin molded product for optical semiconductor encapsulation of the present invention have a linear transmittance of 80% or more at a wavelength of 300 nm and a linear transmittance of 95% or more at a wavelength of 400 nm when formed into a cured body, and thus are excellent in visible light transmittance and UV transmittance. Therefore, the resin composition for optical semiconductor encapsulation and the resin molded product for optical semiconductor encapsulation of the present invention can be suitably used as an encapsulant for light-emitting elements and an encapsulant for light-emitting devices including light-emitting elements, and can be more suitably used as an encapsulant for light-emitting diodes and an encapsulant for light-emitting devices including light-emitting diodes. Similarly, the optical semiconductor device of the present invention is preferably a light-emitting device including a light-emitting element, and more preferably a light-emitting device including a light-emitting diode. Examples of the light-emitting element include UV light-emitting elements such as UV-A (315 - 400 nm) light-emitting elements, UV-B (280 - 315 nm) light-emitting elements, and UV-C (100 - 280 nm) light-emitting elements; and visible light-emitting elements. Among them, a UV light-emitting element is preferable, a UV-B light-emitting element or a UV-C light-emitting element is more preferable, and a UV-B light-emitting element is even more preferable. Also, the light-emitting element is preferably a light-emitting diode. Also, as the light-emitting diode, it can be used as a bullet type, a chip type (surface mount type), etc., but a chip type is preferable, and a high-brightness chip LED is more preferable.

Examples

[0091] Next, the examples will be described together with the comparative examples. However, the present invention is not limited to the following examples.

[0092] The materials used are shown below. Epoxy (epoxy resin): TEPIC-S manufactured by Nissan Chemical Industries, Ltd. (triglycidyl isocyanurate, a compound represented by the following formula (epoxy equivalent 100))

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[0093] Examples and Comparative Examples Each raw material was heated and dissolved at a compounding ratio shown in Table 1 at 100 - 150 °C and mixed. The obtained curable resin composition was heat-treated to obtain a resin composition for light semiconductor encapsulation in a B-stage (semi-cured) state. The heating and dissolution temperature, heat treatment temperature, and heat treatment time were appropriately changed according to the characteristics of the thermosetting resin.

[0094] Using the resin compositions for light semiconductor encapsulation prepared in each example and comparative example, evaluation was carried out by the method shown below. The evaluation results are shown in Table 1.

[0095] [Preparation of test piece (cured body)] Using the resin composition for light semiconductor encapsulation prepared as described above, molding was performed using a mold (curing conditions: heating at 150 °C for 4 minutes) to prepare a cured product for test piece (size: width 50 mm × length 50 mm × thickness 1 mm). This was heated at 150 °C for 3 hours to completely finish curing and obtain a test piece.

[0096] [Linear transmittance] First, the quartz cell was filled with liquid paraffin manufactured by Fuji Film Wako Pure Chemical Corporation, and the baseline was measured using a spectrophotometer V-670 manufactured by JASCO Corporation. Then, the test piece (size: width 50 mm × length 50 mm × thickness 1 mm) prepared above was immersed in the liquid paraffin in the quartz cell, and the light transmittance (linear transmittance) at a wavelength of 300 nm and the light transmittance (linear transmittance) at a wavelength of 400 nm were measured at room temperature (25°C) using a spectrophotometer (V-670 manufactured by JASCO Corporation) while suppressing light scattering on the sample surface. The measurement of the transmission spectrum was performed in the direction perpendicular to the bottom surface of the sample (thickness direction).

[0097] <Heat resistance test> The test piece (size: width 50 mm × length 50 mm × thickness 1 mm) prepared above was left standing in an environment of 150°C for 168 hours. Using the test piece after standing, the light transmittance (linear transmittance) at a wavelength of 400 nm was measured by the same method as above. When the light transmittance was 80% or more, it was judged that the heat resistance was good.

[0098]

Table 1

[0099] From the experimental results shown in Table 1, in the resin compositions for encapsulating optical semiconductors of Examples 1 to 4, both UV transparency and heat resistance could be achieved. On the other hand, in the comparative examples, both UV transparency and heat resistance could not be achieved. In Comparative Example 5, since only a primary antioxidant was blended as an antioxidant, the heat resistance during curing was low and decomposition proceeded during curing, resulting in poor transmittance at 300 nm. It is presumed that this is the case.

Industrial applicability

[0100] The present invention relates to a resin composition for encapsulating an optical semiconductor and a resin molded product for encapsulating an optical semiconductor, which are used for encapsulating an optical semiconductor element, and can be used in the manufacture of an optical semiconductor encapsulant and an optical semiconductor device.

Claims

1. X = (A1 × A2) / A3 + (B1 × B2) / B3 + ··· < 0.0005 ··· (Equation 1) (In (Equation 1), A1 represents the mass ratio of the aromatic compound, A2 represents the number of aromatic rings contained in one molecule of the aromatic compound, and A3 represents the molecular weight of the aromatic compound. A, B ··· represent aromatic compounds.) A resin composition for encapsulating a semiconductor light source, which satisfies the above (Equation 1), contains an epoxy, an alicyclic acid anhydride, and an antioxidant, and has a linear transmittance of 80% or more at a wavelength of 300 nm and a linear transmittance of 95% or more at a wavelength of 400 nm when formed into a cured product (size: width 50 mm × length 50 mm × thickness 1 mm) by the following method. (Method for producing a cured product) The resin composition is heated and molded at 150 °C for 4 minutes, and then heated at 150 °C for 3 hours to obtain a cured product.

2. The resin composition for encapsulating a semiconductor light source according to Claim 1, wherein the epoxy is a compound having a non-aromatic ring structure.

3. The resin composition for encapsulating a semiconductor light source according to Claim 1 or 2, which contains a release agent.

4. The release agent is a release agent having a molecular structure having a structural unit represented by the following structural formula (2) and a structural unit represented by structural formula (3), The resin composition for encapsulating a semiconductor light source according to Claim 3, wherein the proportion of the structural unit represented by the structural formula (3) is set to 25 to 95% by mass of the entire molecular structure constituting the release agent. 【Chemical 1】 (In formula (2), m is a positive number from 8 to 100.) 【Chemical 2】 (In formula (3), n is a positive number.)

5. The resin composition for encapsulating a semiconductor light source according to any one of Claims 1 to 4, wherein the antioxidant is a compound having a phosphite ester structure.

6. The resin composition for encapsulating a semiconductor light source according to any one of Claims 1 to 5, which is for a light-emitting diode.

7. The resin composition for encapsulating a semiconductor light source according to any one of Claims 1 to 5, which is for a UV-B light-emitting diode.

8. A resin molded product for encapsulating a semiconductor light source, which contains the resin composition for encapsulating a semiconductor light source according to any one of Claims 1 to 7.

9. A semiconductor light source encapsulant obtained by molding the resin molded product for encapsulating a semiconductor light source according to Claim 8.

10. A semiconductor light source device comprising a semiconductor light source element and the semiconductor light source encapsulant according to Claim 9 for encapsulating the semiconductor light source element.

11. The semiconductor light source device according to Claim 10, wherein the semiconductor light source element is a light-emitting diode.

12. The optical semiconductor device according to claim 10, wherein the optical semiconductor element is a UV-B light-emitting diode.

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