Resin composition for sealing optical semiconductor, resin molded product for sealing optical semiconductor, optical semiconductor sealing material, and optical semiconductor device

Abstract

The objective of this invention is to provide a resin composition for sealing photonic semiconductors that combines UV transmittance and heat resistance, as well as a molded resin article for sealing photonic semiconductors, a photonic semiconductor sealing material, and a photonic semiconductor device using the same. The resin composition for sealing photonic semiconductors of this invention satisfies the following (Formula 1): X = (A1 × A2) / A3 + (B1 × B2) / B3 + ... < 0.0005 ... (Formula 1) (where A1 represents the mass ratio of the aromatic compound, A2 represents the number of aromatic rings contained in one molecule of the aromatic compound, A3 represents the molecular weight of the aromatic compound; A, B... represent aromatic compounds). It also contains an epoxy resin, an alicyclic anhydride, and an antioxidant, and when formed into a cured body (size: width 50 mm × length 50 mm × thickness 1 mm), it 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.

Description

Technical Field

[0001] This invention relates to a resin composition for sealing optical semiconductors, a molded resin for sealing optical semiconductors, an optical semiconductor sealing material, and an optical semiconductor device. Prior Technology

[0002] Optical semiconductor devices are sealed using ceramic or plastic encapsulation to form their components. However, ceramic encapsulation materials are relatively expensive and have poor mass production capabilities; therefore, plastic encapsulation has become the mainstream method. Among these, the technique of pre-molding epoxy resin compositions into ingots and then transferring the resulting material into molded sheets has become the mainstream method in terms of workability, mass production capabilities, and reliability.

[0003] Optical semiconductors are widely used in the ultraviolet (UV) to infrared (IR) light range depending on their application. The light transmittance or light resistance required for the sealing resin of optical semiconductors varies depending on the wavelength. For example, according to Patent Document 1, by formulating a specific silicone resin, good lightfastness can be obtained even with light of short wavelengths (e.g., 350-500 nm). [Previous Technical Documents] [Patent Literature]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2012-241180 Summary of the Invention

[0005] [The problem the invention aims to solve]

[0006] The inventors conducted intensive research and determined that the technology described in Patent Document 1 has room for improvement in terms of UV transmittance. Furthermore, the inventors conducted intensive research in this area and determined that, especially regarding the photoresist sealing material for shorter wavelength regions (e.g., UV-B in the range of 280-315 nm), when organic materials are used, the light absorption of the photoresist sealing material may damage the light-emitting function of the LED (Light Emitting Diode), thus there is room for improvement in terms of UV transmittance. Furthermore, it has been newly determined that in order to ensure UV transmittance, it is necessary to exclude raw materials with aromatic rings that absorb light in the UV region, such as antioxidants (materials with aromatic rings). However, in this case, there is a problem that it is difficult to achieve high functionality such as heat resistance. The purpose of this invention is to solve the aforementioned problems newly discovered by the inventors and provide a resin composition for sealing optical semiconductors that combines UV transmittance and heat resistance, as well as a molded article of the same for sealing optical semiconductors, an optical semiconductor sealing material, and an optical semiconductor device. [Technical means to solve the problem]

[0007] This invention relates to a resin composition for sealing optical semiconductors, which satisfies the following (Formula 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, A3 represents the molecular weight of the aromatic compound; A, B... represent aromatic compounds) It contains epoxy resin, alicyclic anhydride, and antioxidants, and when a hardened body (size: 50 mm width × 50 mm length × 1 mm thickness) is made 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 manufacturing hardened substrates) The resin composition was heated at 150°C for 4 minutes to form it, and then heated at 150°C for 3 hours to obtain a hardened body.

[0008] The epoxy resins mentioned above are preferably compounds with non-aromatic ring structures.

[0009] The aforementioned resin composition for sealing optical semiconductors preferably contains a release agent.

[0010] The aforementioned release agent preferably has a molecular structure having structural units represented by structural formula (2) and structural units represented by structural formula (3), and It is formed by setting the proportion of the structural unit represented by the above structural formula (3) to 25-95% by mass of the molecular structure of the release agent. [Chemistry 1] (In equation (2), m is a positive number from 8 to 100) [Chemistry 2] (In equation (3), n is a positive number)

[0011] The antioxidants mentioned above are preferably compounds with a phosphite structure.

[0012] The above-mentioned resin composition for sealing optical semiconductors is preferably used in light-emitting diodes, and more preferably in UV-B light-emitting diodes.

[0013] Furthermore, the present invention relates to a resin molded article for sealing optical semiconductors comprising the above-described resin composition for sealing optical semiconductors.

[0014] Furthermore, the present invention relates to an optical semiconductor sealing material obtained by molding the above-mentioned resin molding article for optical semiconductor sealing.

[0015] Furthermore, the present invention relates to an optical semiconductor device having an optical semiconductor element and the aforementioned optical semiconductor sealing material for sealing the optical semiconductor element.

[0016] In the aforementioned optical semiconductor device, the optical semiconductor element is preferably a light-emitting diode, and more preferably a UV-B light-emitting diode. [Effects of the Invention]

[0017] The optical semiconductor sealing resin composition of the present invention satisfies the above (Formula 1) and contains epoxy resin, alicyclic anhydride and antioxidant. When a hardened body (size: width 50 mm × length 50 mm × thickness 1 mm) is made 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, it can have both UV transmittance and heat resistance. Implementation

[0018] 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, A3 represents the molecular weight of the aromatic compound; A, B... represent aromatic compounds) The optical semiconductor sealing resin composition of the present invention satisfies the above (Formula 1), and contains epoxy resin, alicyclic anhydride and antioxidant, and when a hardened body (size: width 50 mm × length 50 mm × thickness 1 mm) is made 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 manufacturing hardened substrates) The resin composition was heated at 150°C for 4 minutes to form it, and then heated at 150°C for 3 hours to obtain a hardened body. This allows it to have both UV transmittance and heat resistance.

[0019] The reason for achieving the above-mentioned effect through the above composition is speculated as follows. In the above (Formula 1), X represents the number of aromatic rings (number / g) in 1 g of the resin composition for sealing optical semiconductors. Satisfying the above (Formula 1) means that the number of aromatic rings in the composition is small, and since the cured body is prepared 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, good UV transmittance can be obtained. Furthermore, by satisfying the above requirements and containing epoxy resin, alicyclic anhydride, and antioxidants, good UV transmittance and good heat resistance can be obtained. Thus, since it contains epoxy resin, alicyclic anhydride, and antioxidant, and satisfies the above (Formula 1), and when the cured body is made by the above method, the linear transmittance at a wavelength of 300 nm is more than 80%, and the linear transmittance at a wavelength of 400 nm is more than 95%, it can have both UV transmittance and heat resistance.

[0020] <Resin Composition for Sealing Optical Semiconductors> The resin composition for sealing optical semiconductors of the present invention satisfies the following (Formula 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, A3 represents the molecular weight of the aromatic compound; A, B... represent aromatic compounds)

[0021] A1 represents the mass ratio of aromatic compounds, that is, the mass ratio of aromatic compound A in the composition. For example, when 1 part by mass of 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 aromatic compound A, that is, the number of aromatic rings contained in one molecule of aromatic compound A. A3 represents the molecular weight of an aromatic compound, that is, the molecular weight of aromatic compound A. A, B, etc. represent aromatic compounds. For each aromatic compound, calculate (A1×A2) / A3. Add the results of the calculations for all aromatic compounds to calculate X.

[0022] If X is less than 0.0005, it is better to be below 0.0004. Since smaller is better, there is no specific limit on the lower limit.

[0023] When the resin composition for sealing optical semiconductors of the present invention is cured 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. To prepare this composition, the following guidelines should be followed. (1) Use compounds with fewer aromatic rings. The reason is that aromatic rings have high light absorption at 250 nm to 320 nm. (2) Even when using compounds with aromatic rings, compounds without conjugated structures should be used. The reason is that compounds with aromatic rings and conjugated structures have high light absorption in the range of 280 nm to 320 nm, while compounds with aromatic rings but without conjugated structures have almost no light absorption in the range of 280 nm to 400 nm. (3) Use compounds containing cyclohexane. The reason is that compounds containing cyclohexane have almost no light absorption in the range of 280 nm to 400 nm.

[0024] The resin composition for sealing optical semiconductors of the present invention contains epoxy resin, alicyclic anhydride, and an antioxidant.

[0025] <<Thermosetting Resins>> As for epoxy resins, those with less coloring are preferred. Examples include: bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenolic varnish type epoxy resin, alicyclic epoxy resin, triglycidyl isocyanate, hydantoin epoxy resin and other heterocyclic epoxy resins, hydrogenated bisphenol A type epoxy resin, aliphatic epoxy resin, glycidyl ether type epoxy resin, cresol varnish type epoxy resin, etc. These can be used alone or in combination of two or more. Among them, compounds with non-aromatic ring structures (epoxy resins) are preferred, and compounds without aromatic rings are even more preferred. The reason is that when using epoxy resins with aromatic rings, such as bisphenol A type epoxy resin, it is difficult to satisfy the above-mentioned (Equation 1). Furthermore, when a cured body is prepared using the above method, the linear transmittance at 300 nm is greater than 80%, and the linear transmittance at 400 nm is greater than 95%, potentially resulting in poor UV transmittance. However, by using compounds with non-aromatic ring structures as epoxy resins, it is easier to satisfy the above-mentioned (Equation 1). When a cured body is prepared using the above method, the linear transmittance at 300 nm is greater than 80%, and the linear transmittance at 400 nm is greater than 95%, resulting in superior UV transmittance. Furthermore, better heat resistance can also be obtained.

[0026] As a non-aromatic ring structure, it can be any saturated or unsaturated ring structure that does not possess aromaticity (preferably, the ring does not contain unsaturated bonds), and there are no particular limitations. Examples include non-aromatic heterocyclic structures and alicyclic structures. Among these, non-aromatic heterocyclic structures are preferred. Furthermore, in this specification, a non-aromatic heterocyclic structure means a saturated or unsaturated ring structure containing atoms other than carbon atoms and carbon atoms that is not aromatic (preferably, the ring does not contain unsaturated bonds). In this specification, an alicyclic structure means a saturated or unsaturated carbon ring structure that is not aromatic (preferably, the carbon ring does not contain unsaturated bonds).

[0027] There is no particular limitation on the number of non-aromatic rings, but it is preferable to have 3 or more, more preferably 4 or more, and even more preferably 5 or more, and preferably 13 or less, even more preferably 10 or less, and even more preferably 7 or less. If it is within the above range, there is a tendency to better balance UV transmittance and heat resistance.

[0028] The non-aromatic ring can be monocyclic, polycyclic, or cross-linked. Among these, monocyclic is preferred.

[0029] The atoms other than carbon atoms present in the non-aromatic heterocycle ring structure are not particularly limited, and examples include oxygen atoms, nitrogen atoms, sulfur atoms, boron atoms, silicon atoms, and phosphorus atoms. These can be used alone or in combination of two or more. Among them, oxygen atoms, nitrogen atoms, and sulfur atoms are preferred, oxygen atoms and nitrogen atoms are more preferred, and nitrogen atoms are even more preferred.

[0030] The number of atoms other than carbon atoms in the non-aromatic heterocycle ring structure is not particularly limited, but it is preferably 1 or more, more preferably 2 or more, and more preferably 5 or less, more preferably 4 or less. If it is within the above range, there is a tendency to better balance UV transmittance and heat resistance.

[0031] As a compound with a non-aromatic ring structure, it is sufficient to have a non-aromatic ring structure, or it may have multiple non-aromatic ring structures in the molecule. Preferably, a compound with a non-aromatic ring structure does not have an aromatic ring.

[0032] The type of epoxy resin (a compound with a non-aromatic ring structure) is not particularly limited. Examples include: hydrogenated bisphenol A type epoxy resin, hydrogenated bisphenol F type epoxy resin, hydrogenated phenolic varnish type epoxy resin, hydrogenated cresol phenolic varnish type epoxy resin, alicyclic epoxy resin, triglycidyl isocyanate, hydantoin epoxy resin, 3,4-epoxycyclohexane carboxylate, and 1,2-epoxy-4-(2-epoxyethylene)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol. These can be used alone or in combination of two or more. Among them, triglycidyl isocyanate, 3,4-epoxycyclohexane carboxylate, and 1,2-epoxy-4-(2-epoxyethylene)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol are preferred, and triglycidyl isocyanate is even more preferred.

[0033] Of 100% by weight of epoxy resin, the proportion of epoxy resin with a non-aromatic ring structure (preferably triglycidyl isocyanurate) is preferably 40% by weight or more, more preferably 60% by weight or more, further preferably 80% by weight or more, especially 90% by weight or more, most preferably 95% by weight or more, and can also be 100% by weight. If it is within the above range, there is a tendency to better balance UV transmittance and heat resistance.

[0034] The resin composition for sealing optical semiconductors of the present invention may also contain thermosetting resins other than epoxy resins.

[0035] In 100% by weight of thermosetting resin, the proportion of epoxy resin is preferably 10% by weight or more, more preferably 20% by weight or more, further preferably 30% by weight or more, especially preferably 60% by weight or more, most preferably 80% by weight or more, further preferably 90% by weight or more, and can also be 100% by weight. If it is within the above range, there is a tendency to better balance UV transmittance and heat resistance.

[0036] Hardening Agent The resin composition for sealing optical semiconductors of the present invention contains alicyclic anhydride as a curing agent. By containing alicyclic anhydride as a curing agent, it is easier to satisfy the above-mentioned (Formula 1) condition, and when the cured body is prepared 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, thereby resulting in better UV transmittance. Furthermore, better heat resistance can also be obtained. In this specification, alicyclic anhydride means a compound having an anhydride group (preferably a carboxylic anhydride group) and an alicyclic structure. Hardeners can be used alone or in combination of two or more.

[0037] Examples of alicyclic anhydrides include: hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyl terephthalic anhydride, terephthalic anhydride, methyl hexahydrophthalic anhydride, methyl tetrahydrophthalic anhydride, dimethyl tetrahydrophthalic anhydride, norethene dicarboxylic anhydride, methyl bicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride, bicyclo[2.2.1]heptane-2,3-dicarboxylic anhydride, bicyclo[2.2.1]heptane-5-ene-2,3-dicarboxylic anhydride, methyl bicyclo[2.2.1]heptane-5-ene-2,3-dicarboxylic anhydride, cyclopentane tetracarboxylic anhydride, and other alicyclic polycarboxylic anhydrides. These can be used alone or in combination of two or more. Hexahydrophthalic anhydride and methyl hexahydrophthalic anhydride are preferred, and hexahydrophthalic anhydride is even more preferred.

[0038] The amount of alicyclic anhydride relative to 100 parts by weight of epoxy resin is preferably 20-200 parts by weight, more preferably 60-180 parts by weight, and the lower limit is preferably more than 100 parts by weight. If it is less than 20 parts by weight, the curing speed will be slower; if it is more than 200 parts by weight, there will be an excess relative to the curing reaction, which may cause a decrease in various physical properties.

[0039] The resin composition for sealing optical semiconductors of the present invention may also contain a curing agent other than alicyclic anhydride. Examples of curing agents other than alicyclic anhydrides include: chain polycarboxylic anhydrides, aromatic polycarboxylic anhydrides, and other anhydride-based curing agents other than alicyclic anhydrides; phenolic curing agents; and amine curing agents. These can be used alone or in combination of two or more.

[0040] In 100% by mass of the hardener, the ratio of alicyclic anhydride is preferably 60% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, and can also be 100% by mass. If it is within the above range, there is a tendency to better balance UV transmittance and heat resistance.

[0041] Antioxidants The resin composition for sealing optical semiconductors of the present invention contains an antioxidant. This provides excellent heat resistance. Antioxidants can be used alone or in combination of two or more. Regarding antioxidants, there are primary antioxidants that capture free radicals generated when bonds break, and secondary antioxidants that decompose oxides; it is preferable to use both. This results in better heat resistance.

[0042] Examples of initial antioxidants include hindered phenolic compounds. These can be used alone or in combination of two or more. Among them, hindered phenolic compounds are preferred for the purpose of obtaining good heat resistance.

[0043] Examples of hindered phenolic compounds include 2,6-di-tert-butyl-p-cresol, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis(3,5-di-tert-butyl-4-hydroxyphenylpropionamide), 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, and tris(3,5-di-tert-butyl-4-hydroxybenzyl)-isocyanurate. These can be used alone or in combination of two or more. For the purpose of obtaining good heat resistance, 2,6-di-tert-butyl-p-cresol and pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] are preferred, and 2,6-di-tert-butyl-p-cresol is even more preferred.

[0044] The amount of the initial antioxidant relative to 100 parts by weight of epoxy resin is preferably 0.5 to 20 parts by weight, more preferably 0.5 to 15 parts by weight, further preferably 0.5 to 5 parts by weight, and even more preferably 0.5 to 3 parts by weight. If the content is less than 0.5 parts by weight, there is a risk of decreased heat resistance; if it exceeds 20 parts by weight, there is a risk of decreased UV transmittance.

[0045] Examples of secondary antioxidants include compounds with phosphite structures and sulfide compounds. These can be used alone or in combination of two or more. Among them, compounds with phosphite structures (phosphite compounds) are preferred for the purpose of obtaining both good heat resistance and good UV transmittance.

[0046] Commonly used antioxidants have aromatic rings and conjugated structures, resulting in high light absorption in the 280 nm to 320 nm range. Phosphite compounds, while possessing aromatic rings, lack conjugated structures and therefore exhibit almost no light absorption in the 280 nm to 400 nm range. Therefore, by formulating phosphite compounds, it is easier to obtain good heat resistance, and when the cured body is prepared using the above method, the linear transmittance at 300 nm is above 80%, and the linear transmittance at 400 nm is above 95%, resulting in superior UV transmittance.

[0047] Examples of phosphite compounds include: triphenyl phosphite, tri(nonylphenyl) phosphite, tricresyl phosphite, triethyl phosphite, tri(2-ethylhexyl) phosphite, tridecyl phosphite, trilauryl phosphite, tri(tetrazyl) phosphite, trioleyl phosphite, diphenyl mono(2-ethylhexyl) phosphite, diphenyl monodecyl phosphite, diphenyl mono(tetrazyl) phosphite, trilauryl thiophosphite, bis(decyl)pentaerythritol diphosphite, tristearyl phosphite, distearyl pentaerythritol diphosphite, and tris(2,4-di-tert-butylphenyl) phosphite. These can be used alone or in combination of two or more. Among these, triphenyl phosphite is preferred for its good heat resistance and good UV transmittance.

[0048] The amount of the secondary antioxidant relative to 100 parts by weight of epoxy resin is preferably 0.5 to 17 parts by weight, more preferably 0.5 to 13 parts by weight, and even more preferably 1 to 10 parts by weight. If the content is less than 0.5 parts by weight, there is a risk of decreased heat resistance; if it exceeds 17 parts by weight, there is a risk of decreased UV transmittance.

[0049] <<Polyols>> The resin composition for sealing optical semiconductors of the present invention preferably contains polyols. This allows for adjustment of the glass transition temperature, resulting in a better balance between UV transmittance and heat resistance. Polyols can be used alone or in combination of two or more.

[0050] Polyols can be compounds with two or more hydroxyl groups, with diols (glycols) being preferred.

[0051] Examples of polyols include diols with a preferred number of carbon atoms of 2 to 10, more preferably 2 to 6, and even more preferably 2 to 5. Examples of such diols include ethylene glycol, propylene glycol, neopentyl glycol, pentylene glycol, and butanediol, with neopentyl glycol being the most preferred. Furthermore, examples of polyols include polyethylene glycol, polypropylene glycol, and other polyalkylene glycols, with polyethylene glycol being preferred. It is also preferable to use diols with the aforementioned number of carbon atoms in combination with polyalkylene diols.

[0052] The amount of polyol in the formulation relative to 100 parts by weight of epoxy resin is preferably 10-60 parts by weight, more preferably 10-50 parts by weight, and even more preferably 10-40 parts by weight. Within this range, there is a tendency to better balance UV transmittance and heat resistance. The smaller the amount of polyol in the formulation, the higher the Tg (heat resistance), and there is a tendency to obtain even better heat resistance.

[0053] <<Release Agent>> The resin composition for sealing optical semiconductors of the present invention preferably contains a release agent. This improves formability and tends to better balance UV transmittance and heat resistance. Release agents can be used alone or in combination of two or more.

[0054] Examples of release agents include release agents with ether bonds, fluorinated release agents, and silicone release agents. These can be used alone or in combination of two or more. Among them, release agents with ether bonds are preferred from the viewpoint of compatibility.

[0055] As a release agent with ether bonds, it is preferred to have a molecular structure having structural units represented by ... [Chemistry 3] (In equation (2), m is a positive number from 8 to 100) [Chemistry 4] (In equation (3), n is a positive number)

[0056] The number of repetitions m in the structural unit represented by the above structural formula (2) is a positive number from 8 to 100, and the proportion of the structural unit represented by the above structural formula (3) is set to be in the range of 25% to 95% by mass of the overall molecular structure of the release agent. More preferably, the number of repetitions m in the structural unit represented by the above structural formula (2) is a positive number from 13 to 60, and the proportion of the structural unit represented by the above structural formula (3) is in the range of 35% to 85% by mass of the overall molecular structure of the release agent. Even more preferably, the number of repetitions m in the structural unit represented by the above structural formula (2) is a positive number from 17 to 40, and the proportion of the structural unit represented by the above structural formula (3) is in the range of 40% to 70% by mass of the overall molecular structure of the release agent. Furthermore, the structural units represented by structural formula (2) and structural formula (3) can exist continuously within the molecular structure, or they can exist in a random or other discontinuous manner. Their existence form is not particularly limited, but a continuous existence form is preferred, namely, a block structure. Moreover, the structural units represented by structural formula (2) and structural formula (3) can also exist in multiples within the molecular structure, rather than just one.

[0057] In addition to the structural units represented by structural formula (2) and structural formula (3), other possible components of the release agent include alkyl groups, alkyl groups, carboxyl groups, ester bonds, ketone bonds, benzene rings, hydrogen atoms, and metal atoms. In the specific release agent described above, the ratio of the structural units represented by structural formula (2) and structural units represented by structural formula (3) in the overall molecular structure is preferably 70-99% by mass.

[0058] The number-average molecular weight of the release agent is preferably 300-12000, more preferably 600-5000, and even more preferably 900-2500. Furthermore, the above-mentioned number-average molecular weight is determined by gel permeation chromatography (GPC) and converted from polystyrene. As a method for identifying the molecular structure of the release agent, the following method can be cited: By using 1H-NMR (Nuclear Magnetic Resonance), the ratio of each structural unit can be determined by the cumulative spectral ratio of hydrogen [-(CH₂CH₂O)-] bonded to adjacent oxygen-bearing carbons and hydrogen [-(CH₂CH₂)-] bonded to inter-carbon carbons. The repetition count is then calculated based on the molecular weight value, thereby identifying the molecular structure of the release agent.

[0059] The amount of release agent relative to 100 parts by weight of epoxy resin is preferably 0.5 to 20 parts by weight, more preferably 5 to 20 parts by weight, and even more preferably 5 to 15 parts by weight. If it is within the above range, it can better balance the tendencies of UV transmittance and heat resistance.

[0060] <<Hardening Accelerator>> The resin composition for sealing optical semiconductors of the present invention preferably contains a curing accelerator. This allows for a better balance between UV transmittance and heat resistance. Hardening accelerators can be used alone or in combination of two or more.

[0061] Examples of hardening accelerators include: tertiary amines such as triethanolamine; imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole, and 2-methyl-4-methylimidazole; organophosphorus compounds such as tributyl(methyl)phosphonium phosphate dimethyl ester salt, tetraphenylborane tetraphenylphosphonium, or triphenylphosphine; diazabicyclic olefin compounds such as 1,8-diazabicyclo[5,4,0]undecene-7 or 1,5-diazabicyclo[4,3,0]nonene-5; etc. These can be used alone or in combination of two or more. Preferably, the compound does not have an aromatic ring, more preferably it is an organophosphorus compound, and even more preferably it is tributyl(methyl)phosphonium phosphate dimethyl ester salt.

[0062] There is no particular limitation on the amount of curing accelerator. For example, it can be appropriately selected from 0.1 to 5 parts by weight relative to 100 parts by weight of epoxy resin, preferably 0.5 to 3 parts by weight, and even more preferably 1 to 2 parts by weight. If the amount of curing accelerator is too small, the curing speed will be slowed down, and productivity will decrease. On the other hand, if the amount of curing accelerator is too large, the curing reaction will be too fast, making it difficult to control the reaction state and potentially causing deviations in the reaction.

[0063] <<Other Additives>> In addition to the above-mentioned components, the optical semiconductor sealing resin composition of the present invention may also use additives such as lubricants, phosphors that cause wavelength changes in light, or inorganic or organic fillers that diffuse light, as needed. These additives may be used alone or in combination of two or more.

[0064] Examples of lubricants include stearic acid, magnesium stearate, calcium stearate, waxes, and talc. Furthermore, when preparing the above-mentioned lubricants, the amount prepared is appropriately set according to the molding conditions, for example, it is suitable to be set to 0.1 to 0.4% of the total mass of the resin composition.

[0065] Examples of phosphors that cause wavelength changes in light or inorganic and organic fillers that diffuse light include: 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. Furthermore, when formulating phosphors or inorganic and organic fillers, the amount can be appropriately set according to the molding conditions. Specifically, in the case of phosphors, the amount of phosphor can be appropriately set within the range of 1% to 60% by mass of the total resin composition. On the other hand, in the case of fillers (organic and inorganic) that scatter light, the amount of light-scattering filler can be appropriately set within the range of 0.5% to 25% by mass of the total resin molded article.

[0066] <<Reactants>> The resin composition for sealing optical semiconductors of the present invention may also include reactants of thermosetting resins and hardeners, as well as reactants of various formulations.

[0067] <Manufacturing Method of Resin Composition for Opto-Semiconductor Sealing> The manufacturing method of the optical semiconductor sealing resin composition of the present invention is not particularly limited as long as the above-mentioned components can be mixed and dispersed. It is preferred to heat treat the components to produce a B-stage (semi-cured) state.

[0068] Regarding the manufacturing method of the optical semiconductor sealing resin composition of the present invention, an example of a manufacturing method including the following steps can be cited: The step of mixing a thermosetting resin, a curing agent, and a curing accelerator to obtain a curable resin composition; and The step of heat-treating the curable resin composition.

[0069] There are no particular limitations on the mixing method; for example, an extruder can be used. There are also no particular limitations on the mixing temperature; it can be appropriately varied depending on the characteristics of the thermosetting resin, or a higher temperature can be set to allow the reaction to occur during mixing. Specifically, 80~150℃ is preferred, and more preferably 110~130℃.

[0070] The shape of the hardened resin composition obtained by mixing is not particularly limited, and examples include: film, sheet, granules, block, etc.

[0071] The thickness of the cured resin composition obtained by mixing is not particularly limited, but it is preferably 1 to 30 mm, more preferably 2 to 20 mm, and even more preferably 2 to 10 mm. If it is less than 1 mm, the thickness is too thin and it is easily affected by moisture absorption. If it exceeds 30 mm, cooling will take time, and there is a tendency for uneven reaction due to internal heat accumulation.

[0072] A B-stage (semi-cured) resin composition for sealing optical semiconductors is obtained by heat treatment of the curable resin composition obtained through mixing. The heat treatment temperature is not particularly limited, but is preferably 25~100℃, more preferably 60~80℃. If the temperature is below 25℃, the curing reaction tends to be slow, resulting in decreased productivity; if the temperature exceeds 100℃, the curing reaction tends to be rapid, making it difficult to terminate the reaction at the specified state. The heat treatment time is not particularly limited and can be appropriately varied according to the characteristics of the thermosetting resin.

[0073] Preferably, the B-stage (semi-cured) optical semiconductor sealing resin composition obtained by heat treatment is supplied to the following steps. The step of pulverizing and / or granulating a heat-treated curable resin composition (B-stage (semi-curable) optical semiconductor sealing resin composition) to obtain a granular curable resin composition.

[0074] In the case of pulverization, the heat-treated resin composition is pulverized to obtain a granular resin composition. Pulverization can be performed using a ball mill, turbine mill, or similar equipment.

[0075] In the case of granulation, the heat-treated resin composition is granulated to obtain a granular resin composition. Alternatively, the resin can be pulverized using a ball mill, turbine mill, or similar equipment before granulation. There are no particular limitations on the granulation method; examples include the use of a dry compression granulator.

[0076] The average particle size of the granules obtained by crushing and / or granulation is not particularly limited, but is preferably 1 to 5000 μm, more preferably 100 to 2000 μm. If it exceeds 5000 μm, there is a tendency for the compressibility to decrease.

[0077] The preferred step for obtaining the above-mentioned granular curable resin composition is to granulate the heat-treated curable resin composition (B-stage (semi-curable) optical semiconductor sealing resin composition) to obtain the granular curable resin composition.

[0078] Regarding the optical semiconductor sealing resin composition of the present invention obtained by the above-described manufacturing method, when a hardened body (size: 50 mm width × 50 mm length × 1 mm thickness) is prepared 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 manufacturing hardened substrates) The resin composition was heated at 150°C for 4 minutes to form it, and then heated at 150°C for 3 hours to obtain a hardened body.

[0079] The linear transmittance at a wavelength of 300 nm is 80% or higher, preferably 81% or higher, more preferably 83% or higher, and even more preferably 85% or higher, with no particular upper limit. This allows light near the 300 nm wavelength to pass through appropriately, thereby improving the luminous efficiency of the light-emitting element.

[0080] The linear transmittance at a wavelength of 400 nm is 95% or higher, preferably 96% or higher, even more preferably 97% or higher, and further preferably 98% or higher, with no particular upper limit. This allows light near the 400 nm wavelength to pass through appropriately, thereby improving the luminous efficiency of the light-emitting element.

[0081] The aforementioned linear transmittance was determined by measuring the transmission spectrum of the hardened material at wavelengths of 300 nm or 400 nm using a spectrophotometer. Furthermore, the transmission spectrum was measured in a direction perpendicular to the bottom (or top) surface of the sample.

[0082] <Resin Molded Material for Sealing Optical Semiconductors> Examples of resin molded materials for sealing optical semiconductors according to the present invention include tablets and sheets. By forming the optical semiconductor element that constitutes the optical semiconductor device, the element can be sealed.

[0083] When the resin molding for sealing optoelectronic semiconductors is in the form of a wafer, its volume is not particularly limited, but is preferably 1 to 100 cm3, and more preferably 10 to 100 cm3.

[0084] The method for manufacturing the resin molded article for sealing optical semiconductors of the present invention, in addition to the steps described above, also includes, for example, the following steps: The step of forming the granular resin composition obtained by the step of obtaining the above-mentioned granular curable resin composition.

[0085] The optical semiconductor sealing resin composition of the present invention is molded to obtain the optical semiconductor sealing resin molded article of the present invention. This allows for the acquisition of an optical semiconductor sealing resin molded article containing the optical semiconductor sealing resin composition. Examples of molded articles include ingots or sheets, and examples of molding methods include ingot forming to obtain ingots and extrusion forming to obtain sheets. The resulting molded article is a high-quality molded article possessing both UV transmittance and heat resistance.

[0086] A resin composition for sealing optical semiconductors is molded to obtain a molded resin article for sealing optical semiconductors, but the compositions of the resin composition for sealing optical semiconductors and the molded resin article for sealing optical semiconductors are substantially the same.

[0087] When the molded product is a sheet, the conditions for forming the sheet can be appropriately adjusted according to the composition of the resin composition for sealing optoelectronic semiconductors. Generally, the compression ratio during forming is appropriately set to 90-96%. The reason is that if the compression ratio is less than 90%, the density of the sheet may decrease and it may easily break. Conversely, if the compression ratio is greater than 96%, cracks may occur during forming, resulting in defects or breakage during release.

[0088] <Optical semiconductor sealing materials, optical semiconductor devices> The present invention discloses a resin molded article for sealing optical semiconductors, which is used to seal optical semiconductor elements by molding methods such as transfer molding to manufacture optical semiconductor devices. That is, the resin molded article for sealing optical semiconductors of the present invention is an optical semiconductor sealing material that seals optical semiconductor elements with resin by molding such as transfer molding. Thus, the optical semiconductor sealing material of the present invention is obtained by molding the resin molded article for sealing optical semiconductors of the present invention. In this specification, the optical semiconductor sealing material is a component formed in such a way as to cover the optical semiconductor element constituting the optical semiconductor device, thereby sealing the element.

[0089] The optical semiconductor sealing resin composition and the optical semiconductor sealing resin molded article of the present invention can have both UV transmittance and heat resistance. Therefore, the optical semiconductor sealing material obtained by molding the optical semiconductor sealing resin composition and the optical semiconductor sealing resin molded article of the present invention is a high-quality optical semiconductor sealing material that can have both UV transmittance and heat resistance.

[0090] The optical semiconductor device of the present invention includes an optical semiconductor element and an optical semiconductor sealing material of the present invention for sealing the optical semiconductor element. Because the optical semiconductor device of the present invention includes the optical semiconductor sealing material of the present invention, it is a high-quality optical semiconductor device that combines UV transmittance and heat resistance.

[0091] When the optical semiconductor sealing resin composition and the optical semiconductor sealing resin molded article of the present invention are made into a hardened body, the linear transmittance at a wavelength of 300 nm is more than 80% and the linear transmittance at a wavelength of 400 nm is more than 95%, thus exhibiting excellent visible light transmittance and UV transmittance. Therefore, the optical semiconductor sealing resin composition and the optical semiconductor sealing resin molded article of the present invention can be suitably used as sealing materials for light-emitting elements and sealing materials for light-emitting devices having light-emitting elements, and can be more suitably used as sealing materials for light-emitting diodes and sealing materials for light-emitting devices having light-emitting diodes. Similarly, the optical semiconductor device of the present invention is preferably a light-emitting device having a light-emitting element, and more preferably a light-emitting device having a light-emitting diode. Examples of light-emitting elements include: UV-A (315-400 nm) light-emitting elements, UV-B (280-315 nm) light-emitting elements, UV-C (100-280 nm) light-emitting elements, etc.; visible light light-emitting elements; preferably UV light-emitting elements, more preferably UV-B light-emitting elements, UV-C light-emitting elements, and even more preferably UV-B light-emitting elements. Furthermore, the light-emitting element is preferably a light-emitting diode. Furthermore, as a light-emitting diode, it can be used in bullet-shaped, sheet-shaped (surface-mounted) and other types, with sheet-shaped being preferred, and high-brightness sheet-shaped LEDs being even more preferred. [Example]

[0092] Secondly, the embodiments will be described with reference to comparative examples. However, the present invention is not limited to the following embodiments.

[0093] The materials used are shown below. Epoxy resin: TEPIC-S (triglycidyl isocyanate, a compound represented by the following formula (epoxy equivalent 100)) manufactured by Nissan Chemical Co., Ltd. [Chemistry 5] Alicyclic anhydrides: RIKACID MH-700G manufactured by Shin Nippon Rika Co., Ltd. (a mixture of hexahydrophthalic anhydride and 4-methylhexahydrophthalic anhydride, a mixture of compounds represented by the following formula) [Chemistry 6] Polyol 1: P-700 (polyethylene glycol, the compound represented by the following formula (n=11)) manufactured by ADEKA Corporation [Chemistry 7] Polyol 2: Neopentyl glycol (the compound represented by the following formula) [Chemistry 8] Internal release agent: The compound represented by the following formula (m=26, n=17, where the number of repeating units is the average of all molecules, not all molecules have the same number of repeating units). [Chemistry 9] Initial antioxidant: H-BHT (2,6-di-tertiary butyl-p-cresol, the compound represented by the following formula) manufactured by Honshu Chemical Industry Co., Ltd. [Chemistry 10] Secondary antioxidant 1: TPP-R (triphenyl phosphite, the compound represented by the following formula) manufactured by Daihachi Chemical Industry Co., Ltd. [Chemistry 11] Secondary antioxidant 2: HCA (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) manufactured by Sanguang Company Hardening accelerator: PX-4MP (dimethyl tributyl(methyl)phosphonium phosphate, a compound represented by the following formula) manufactured by Nippon Chemical Industries, Ltd. [Chemistry 12]

[0094] Examples and Comparative Examples The raw materials were heated and melted at 100-150°C and mixed according to the proportions shown in Table 1. The resulting curable resin composition was then heat-treated to obtain a B-stage (semi-cured) resin composition for sealing optical semiconductors. The heating melting temperature, heat treatment temperature, and heat treatment time were appropriately adjusted according to the characteristics of the thermosetting resin.

[0095] The optical semiconductor sealing resin compositions prepared in the various embodiments and comparative examples were evaluated using the methods described below. The evaluation results are shown in Table 1.

[0096] <Preparation of the Experimental Piece (Hardened Body)> Using the optical semiconductor sealing resin composition prepared as described above, a mold was used to form a hardened test piece (size: width 50 mm × length 50 mm × thickness 1 mm). The hardened test piece was then heated at 150°C for 3 hours to completely complete the hardening process, thus obtaining the test piece.

[0097] Linear transmittance First, the quartz tank was filled with liquid paraffin manufactured by Fujifilm and Kojun Pharmaceutical Co., Ltd., and the baseline was determined using a Nippon Spectrophotometer V-670. Next, the prepared test specimen (size: 50 mm width × 50 mm length × 1 mm thickness) was immersed in the liquid paraffin in the quartz tank. Under conditions that suppressed light scattering from the sample surface, the light transmittance (linear transmittance) at 300 nm and 400 nm was measured at room temperature (25°C) using the spectrophotometer (Nippon Spectrophotometer V-670). Furthermore, the transmission spectrum was measured in a direction perpendicular to the bottom surface of the sample (thickness direction).

[0098] <Heat Resistance Test> The test piece (size: 50 mm wide × 50 mm long × 1 mm thick) prepared above was left to stand at 150°C for 168 hours. The light transmittance (linear transmittance) at a wavelength of 400 nm was then measured using the same method as described above. A light transmittance of 80% or higher was considered to indicate good heat resistance.

[0099] [Table 1] Molecular weight (g / mol) Number of aromatic rings (indivual) Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Mixing quantity (parts by weight) Epoxy resin 0 100 100 100 100 100 100 100 100 100 Alicyclic anhydrides 0 152 152 152 152 152 152 152 152 152 Polyol 1 0 15 15 15 15 15 15 15 15 15 Polyol 2 0 19.2 19.2 19.2 19.2 19.2 19.2 19.2 19.2 19.2 Internal release agent 0 10 10 10 10 10 10 10 10 10 Initial antioxidants 220.34 1 1 1 1 0 1 1 1 1 1 Secondary antioxidant 1 310.29 3 1 5 10 1 0 0 0 20 0 Secondary antioxidant 2 216 2 0 0 0 0 0.012 0.03 0.5 0 0 hardening accelerator 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 total 299.4 303.4 308.4 298.4 298.412 298.43 298.9 318.4 298.4 Evaluate Aromatic equivalent X 0.00005 0.00017 0.00033 0.00003 0.00002 0.00002 0.00003 0.00062 0.00002 300 nm 1 mm transmittance 86.7 81.9 80.4 83.8 57.9 24.9 1 69.9 75.8 400 nm 1 mm transmittance 98.5 97.7 97.6 96.4 96 98 97 93.2 96.5 Transmittance at 400 nm per mm after 168 hours at 150℃ 91.9 95.3 92.4 85.1 91.9 91.9 94.6 90 92.2

[0100] According to the experimental results shown in Table 1, the optical semiconductor sealing resin compositions of Examples 1-4 can combine UV transmittance and heat resistance. On the other hand, the comparative examples could not simultaneously possess both UV transmittance and heat resistance. Furthermore, in Comparative Example 5, only an initial antioxidant was formulated as an antioxidant, resulting in low heat resistance during curing and decomposition during curing. It is speculated that this is the reason for the poor transmittance at 300 nm. [Industrial Applicability]

[0101] This invention relates to a resin composition for sealing optical semiconductor elements and a molded resin for sealing optical semiconductor elements, which can be used in the manufacture of optical semiconductor sealing materials and optical semiconductor devices.

Claims

1. A resin composition for sealing optical semiconductors, which satisfies the following (Formula 1), X=(A1×A2) / A3+(B1×B2) / B3+・・・≦0.00033・・・(Formula 1) (in (Formula 1), A1 represents the mass ratio of aromatic compounds, A2 represents the number of aromatic rings contained in one molecule of aromatic compound, A3 represents the molecular weight of aromatic compound, and A, B・・・ represent aromatic compounds) and contains epoxy resin, alicyclic anhydride, and antioxidant, and when a hardened body (size: width 50 mm × length 50 mm × thickness 1 mm) is prepared 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 preparing the hardened body) The resin composition is heated at 150°C for 4 minutes to form it, and then heated at 150°C for 3 hours to obtain the hardened body.

2. The resin composition for sealing optical semiconductors as claimed in claim 1, wherein the epoxy resin is a compound having a non-aromatic ring structure.

3. The optical semiconductor sealing resin composition of claim 1 or 2 contains a release agent.

4. The optical semiconductor sealing resin composition of claim 3, wherein the release agent has a molecular structure having a structural unit represented by the following structural formula (2) and a structural unit represented by the following structural formula (3), and the ratio of the structural unit represented by the above structural formula (3) is set to 25 to 95% by mass of the total molecular structure constituting the release agent; [Chemistry 1] (in formula (2), m is a positive number from 8 to 100) [Chemistry 2] (in formula (3), n is a positive number).

5. The resin composition for sealing optical semiconductors as claimed in claim 1 or 2, wherein the antioxidant is a compound having a phosphite structure.

6. The optical semiconductor sealing resin composition of claim 1 or 2, used in a light-emitting diode.

7. The photoresist composition for sealing photodiodes as claimed in claim 1 or 2, which is used in a UV-B light-emitting diode.

8. A resin molded article for sealing optical semiconductors, comprising the optical semiconductor sealing resin composition of any one of claims 1 to 7.

9. A photoelectric semiconductor sealing material, which is obtained by molding a photoelectric semiconductor sealing resin molded article as claimed in claim 8.

10. An optical semiconductor device comprising an optical semiconductor element and an optical semiconductor sealing material as claimed in claim 9 for sealing the optical semiconductor element.

11. The optical semiconductor device of claim 10, wherein the optical semiconductor element is a light-emitting diode.

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