High-transparency diode methyltetrahydrophthalic anhydride encapsulating material and preparation method thereof

Abstract

This invention relates to the field of semiconductor packaging materials technology, and discloses a high-transmittance diode methyltetrahydrophthalic anhydride packaging material and its preparation method, comprising the following raw materials in parts by weight: 40-60 parts of modified bisphenol A epoxy resin, 30-50 parts of methyltetrahydrophthalic anhydride, 5-15 parts of modified nano-silica, 0.5-2 parts of light stabilizer, 1-5 parts of coupling agent, 0.5-1 part of accelerator, 0.1-0.3 parts of antioxidant, and 5-10 parts of solvent. The modified bisphenol A epoxy resin, molten methyltetrahydrophthalic anhydride, and solvent are mixed to obtain a resin mixture; modified nano-silica, light stabilizer, coupling agent, accelerator, and antioxidant are added sequentially and stirred to obtain a mixture; the mixture is then subjected to vacuum degassing and curing to obtain the high-transmittance diode methyltetrahydrophthalic anhydride packaging material. The preparation method of this invention is simple, effectively reduces internal defects in the material, improves production efficiency and product quality, and is suitable for large-scale industrial production.

Description

Technical Field

[0001] This invention relates to the field of semiconductor packaging materials technology, specifically to a high-transmittance diode methyltetrahydrophthalic anhydride packaging material and its preparation method. Background Technology

[0002] In the field of optoelectronic devices such as semiconductor light-emitting diodes (LEDs), packaging materials play a crucial role. Packaging materials must not only provide physical protection for the internal chip, preventing damage from external environments (such as moisture, oxygen, and mechanical stress), but also possess excellent optical properties to ensure that optoelectronic devices can emit and transmit light efficiently.

[0003] Methyltetrahydrophthalic anhydride, a commonly used epoxy resin curing agent, is widely used in semiconductor packaging materials. However, existing methyltetrahydrophthalic anhydride-based packaging materials still have certain shortcomings in optical performance. For example, their light transmittance is not high enough, which limits the luminous efficiency of optoelectronic devices. Furthermore, their long-term stability needs improvement, affecting the lifespan and performance of optoelectronic devices. In addition, existing fabrication processes also have deficiencies in material uniformity and defect control, making it difficult to meet the production requirements of high-performance packaging materials. Therefore, developing a high-transmittance and stable diode methyltetrahydrophthalic anhydride packaging material and its efficient fabrication method is of significant practical importance. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] To address the shortcomings of existing technologies, this invention provides a high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material and its preparation method.

[0006] (II) Technical Solution

[0007] To achieve the above objectives, the present invention provides the following technical solution: a high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material, comprising the following raw materials in parts by weight:

[0008] The mixture contains 40-60 parts of modified bisphenol A epoxy resin, 30-50 parts of methyltetrahydrophthalic anhydride, 5-15 parts of modified nano-silica, 0.5-2 parts of light stabilizer, 1-5 parts of coupling agent, 0.5-1 part of accelerator, 0.1-0.3 parts of antioxidant, and 5-10 parts of solvent.

[0009] The preparation method of modified bisphenol A epoxy resin includes the following steps:

[0010] A1. Add bisphenol A type epoxy resin and dimethyl terephthalate to a reaction vessel at a molar ratio of 1:0.2~0.5, add triphenylphosphine catalyst at an amount of 0.1~0.3% of the total mass of the reactants, and react at 180~200℃ for 3~5 h.

[0011] A2. Cool the above product to 60-80℃, transfer it to a reactor equipped with a stirrer and nitrogen protection device, add 8-12% (by weight) of epoxy resin diethyl maleate and 6-10% (by weight) of ethylene glycol dimethacrylate, start stirring, and control the speed at 150-200 r / min. Add 3% (by weight) of benzoyl peroxide to the reaction system. Under nitrogen protection, heat to 90-100℃ and react for 4-6 h. After the reaction is completed, cool to room temperature and perform vacuum distillation at 50-60℃ and a vacuum degree of -0.08 to -0.1 MPa to remove unreacted monomers and small molecule byproducts.

[0012] A3. Add 3-8% by weight of glycidyl methacrylate to the reaction system, react at 90-110℃ for 1-2 h, and cool to room temperature to obtain modified bisphenol A type epoxy resin.

[0013] Preferably, the preparation method of nano-silica includes the following steps:

[0014] B1. Add nano-silica to a 5-10% (w / w) 3-aminopropyltriethoxysilane ethanol solution, with a mass ratio of nano-silica to solution of 1:10-20. Stir and react at 50-60℃ for 3-4 h. After the reaction is complete, centrifuge, wash with ethanol 3-5 times, and vacuum dry at 80-90℃ for 6-8 h to obtain surface-aminated nano-silica.

[0015] B2. Surface-aminated nano-silica is dispersed in anhydrous toluene to form a suspension with a mass fraction of 5-8%. 15-20% of the mass of 9,10-diphenylethynyl anthracene nano-silica is added to the suspension, along with 1-3% of the mass of 9,10-diphenylethynyl anthracene catalyst. The mixture is refluxed under nitrogen protection for 8-12 h. After the reaction is complete, it is cooled to room temperature, centrifuged, washed sequentially with toluene and anhydrous ethanol, and vacuum dried at 100-110℃ for 8-10 h.

[0016] B3. Add the above-treated nano-silica to an ethanol solution of tetraethyl orthosilicate, with a mass ratio of tetraethyl orthosilicate to nano-silica of 1~2:1 and a mass fraction of tetraethyl orthosilicate in the ethanol solution of 10~15%. Then add ammonia to adjust the pH of the solution to 9~10, stir the reaction at room temperature for 12~16 h, centrifuge after the reaction is completed, wash with ethanol, and vacuum dry at 80~90℃ for 6~8 h.

[0017] B4. The core-shell structured nano-silica is dispersed in a mixed solution of ethanol and deionized water at a volume ratio of 3:1 to form a suspension with a mass fraction of 5-10%. A mixed aqueous solution of cerium nitrate and lanthanum nitrate is added to the suspension, wherein the molar ratio of cerium nitrate to lanthanum nitrate is 3:1, and the total amount of rare earth elements added is 2-5% of the mass of nano-silica. The pH value is adjusted to 9-10 with ammonia water, and the reaction is stirred at 60-70℃ for 6-8 h. After the reaction is completed, the mixture is centrifuged, washed with deionized water, vacuum dried at 120-130℃ for 10-12 h, and finally calcined at 400-450℃ for 2-3 h to obtain modified nano-silica.

[0018] Preferably, the light stabilizer is one of GW-540, UV-9, and UV-326.

[0019] Preferably, the coupling agent is one of KH-550, KH-560, or titanate coupling agent.

[0020] Preferably, the accelerator is one of 2-methylimidazole, boron trifluoride diethyl ether complex, and benzyltriethylammonium chloride.

[0021] Preferably, the antioxidant is one of 1010, 168, or DSTDP.

[0022] Preferably, the solvent is one of toluene, acetone, and ethyl acetate.

[0023] Preferably, a method for preparing a high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material includes the following steps:

[0024] S1. Place the modified nano-silica in a vacuum drying oven at 120~150℃ and dry for 4~6 h, and heat the high-purity methyltetrahydrophthalic anhydride until it melts;

[0025] S2. Weigh the modified bisphenol A epoxy resin, molten methyltetrahydrophthalic anhydride, and solvent according to the weight proportions, add them to a reaction vessel equipped with a stirring device and heating function, and stir at 70~75℃ and a speed of 150~200 r / min for 30~40 min to form a resin mixture.

[0026] S3. Add the modified nano-silica, light stabilizer, coupling agent, accelerator and antioxidant to the resin mixture in sequence, heat to 80~100℃, and continue stirring at 250~300 r / min for 30~60 min to obtain the mixture.

[0027] S4. Transfer the mixture to a vacuum degassing machine and degas for 20-25 minutes under a vacuum of -0.09 to -0.1 MPa, then raise the temperature to 50-60℃ and degas for 15-20 minutes.

[0028] S5. Quickly inject the degassed material into a mold preheated to 90~100℃, pre-cur it at 100~110℃ for 1.5~2 h, then raise the temperature to 160~170℃ and cure it for 3~5 h. Allow it to cool naturally to room temperature before demolding to obtain the high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material.

[0029] (iii) Beneficial technical effects

[0030] A high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material comprises the following raw materials in parts by weight: 40-60 parts modified bisphenol A type epoxy resin, 30-50 parts methyltetrahydrophthalic anhydride, 5-15 parts modified nano silica, 0.5-2 parts light stabilizer, 1-5 parts coupling agent, 0.5-1 part accelerator, 0.1-0.3 parts antioxidant, and 5-10 parts solvent.

[0031] The process for modifying bisphenol A type epoxy resin involves grafting the benzene ring structure from dimethyl terephthalate onto the epoxy resin molecular chain. Under the initiation of benzoyl peroxide, the double bonds of diethyl maleate and ethylene glycol dimethacrylate undergo copolymerization and crosslinking reactions with the epoxy groups of the epoxy resin, thereby improving the rigidity and regularity of the molecular chain, reducing the free volume between molecular chains, and thus reducing light scattering. End-capping treatment of the epoxy resin molecular chain reduces the polar groups at the molecular chain ends, improving the optical stability of the material.

[0032] The process for modifying nano-silica involves grafting amino groups onto the surface of nano-silica to provide active sites. 9,10-Diphenylethynylanthracene chemically bonds with the amino groups on the nano-silica surface, resulting in a material with high fluorescence quantum yield and good optical transparency, significantly improving the optical properties of nano-silica. Tetraethyl orthosilicate undergoes hydrolysis and condensation on the nano-silica surface to form a uniform silica shell, constructing a core-shell structure. This structure further optimizes the optical refractive index of nano-silica and reduces light scattering at the interface between nano-silica and the resin matrix. Rare earth ions are uniformly deposited on the nano-silica surface. Rare earth elements possess unique electronic structures that can absorb and emit light of specific wavelengths, further enhancing the light transmittance and UV resistance of nano-silica.

[0033] The preparation method of the present invention is simple, effectively reduces internal defects in materials, improves production efficiency and product quality, and is suitable for large-scale industrial production. Detailed Implementation

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0035] Unless otherwise specified, all components of the methyltetrahydrophthalic anhydride encapsulation material for high-transmittance diodes in this invention are commercially available.

[0036] All parts used in this invention are by weight. Example 1

[0037] A high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material comprises the following raw materials in parts by weight:

[0038] The mixture contains 40 parts modified bisphenol A epoxy resin, 30 parts methyltetrahydrophthalic anhydride, 5 parts modified nano silica, 0.5 parts light stabilizer, 1 part coupling agent, 0.5 parts accelerator, 0.1 parts antioxidant, and 5 parts solvent.

[0039] The light stabilizer is GW-540.

[0040] The coupling agent is KH-550.

[0041] The accelerator is 2-methylimidazole.

[0042] The antioxidant is 1010.

[0043] The solvent is toluene.

[0044] The preparation method of modified bisphenol A epoxy resin includes the following steps:

[0045] A1. Bisphenol A type epoxy resin and dimethyl terephthalate were added to a reaction vessel at a molar ratio of 1:0.2. Triphenylphosphine catalyst was added at a rate of 0.1% of the total mass of the reactants. The reaction was carried out at 180°C for 3 h.

[0046] A2. Cool the above product to 60°C and transfer it to a reactor equipped with a stirrer and nitrogen protection device. Add 8% (by weight) of epoxy resin diethyl maleate and 6% (by weight) of ethylene glycol dimethacrylate. Start stirring and control the speed at 150 r / min. Add 3% (by weight) of benzoyl peroxide to the reaction system. Under nitrogen protection, heat to 90°C and react for 4 hours. After the reaction is completed, cool to room temperature and perform vacuum distillation at 50°C and -0.08 MPa to remove unreacted monomers and small molecule byproducts.

[0047] A3. Add 3% by weight of glycidyl methacrylate to the reaction system, react at 90°C for 1 hour, and cool to room temperature to obtain modified bisphenol A type epoxy resin.

[0048] The preparation method of nano-silica includes the following steps:

[0049] B1. Nano-silica was added to a 5% (w / w) 3-aminopropyltriethoxysilane ethanol solution, with a mass ratio of nano-silica to solution of 1:10. The mixture was stirred at 50°C for 3 h. After the reaction was completed, the mixture was centrifuged, washed three times with ethanol, and dried under vacuum at 80°C for 6 h to obtain surface-aminated nano-silica.

[0050] B2. Surface-aminated nano-silica was dispersed in anhydrous toluene to form a suspension with a mass fraction of 5%. 15% of the mass of nano-silica and 9,10-diphenylethynyl anthracene were added to the suspension, along with 1% of the mass of 9,10-diphenylethynyl anthracene as a catalyst. The mixture was refluxed under nitrogen protection for 8 h. After the reaction was completed, the mixture was cooled to room temperature, centrifuged, washed sequentially with toluene and anhydrous ethanol, and dried under vacuum at 100 °C for 8 h.

[0051] B3. Add the nano-silica treated above to an ethanol solution of tetraethyl orthosilicate, with a mass ratio of tetraethyl orthosilicate to nano-silica of 1:1 and a mass fraction of tetraethyl orthosilicate in the ethanol solution of 10%. Then add ammonia water to adjust the pH of the solution to 9, stir the reaction at room temperature for 12 h, centrifuge after the reaction is completed, wash with ethanol, and vacuum dry at 80℃ for 6 h.

[0052] B4. The core-shell structured nano-silica was dispersed in a mixed solution of ethanol and deionized water at a volume ratio of 3:1 to form a suspension with a mass fraction of 5%. A mixed aqueous solution of cerium nitrate and lanthanum nitrate was added to the suspension, wherein the molar ratio of cerium nitrate to lanthanum nitrate was 3:1, and the total amount of rare earth elements added was 2% of the mass of nano-silica. The pH value was adjusted to 9 with ammonia water, and the reaction was stirred at 60℃ for 6 h. After the reaction was completed, the nano-silica was separated by centrifugation, washed with deionized water, vacuum dried at 120℃ for 10 h, and finally calcined at 400℃ for 2 h to obtain modified nano-silica.

[0053] A method for preparing a high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material includes the following steps:

[0054] S1. The modified nano-silica was dried in a vacuum drying oven at 120°C for 4 h, and the high-purity methyltetrahydrophthalic anhydride was heated until it melted.

[0055] S2. Weigh the modified bisphenol A epoxy resin, molten methyltetrahydrophthalic anhydride, and solvent according to the weight proportions, add them to a reaction vessel equipped with a stirring device and heating function, and stir at 70°C and 150 r / min for 30 min to obtain the resin mixture.

[0056] S3. Add the modified nano-silica, light stabilizer, coupling agent, accelerator and antioxidant to the resin mixture in sequence, heat to 80℃, and continue stirring at 250 r / min for 30 min to obtain the mixture.

[0057] S4. Transfer the mixture to a vacuum degassing machine and degas for 20 min under a vacuum of -0.09 MPa, then heat to 50℃ and degas under vacuum for 15 min.

[0058] S5. Quickly inject the degassed material into a mold preheated to 90°C, pre-cur it at 100°C for 1.5 h, then raise the temperature to 160°C and cure it for 3 h. Allow it to cool naturally to room temperature before demolding to obtain the high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material. Example 2

[0059] A high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material comprises the following raw materials in parts by weight:

[0060] The mixture contains 50 parts of modified bisphenol A epoxy resin, 40 parts of methyltetrahydrophthalic anhydride, 10 parts of modified nano-silica, 1 part of light stabilizer, 3 parts of coupling agent, 0.8 parts of accelerator, 0.2 parts of antioxidant, and 7 parts of solvent.

[0061] The light stabilizer is UV-9.

[0062] The coupling agent is KH-560.

[0063] The accelerator is a boron trifluoride diethyl ether complex.

[0064] The antioxidant content is 168.

[0065] The solvent is acetone.

[0066] The preparation method of modified bisphenol A epoxy resin includes the following steps:

[0067] A1. Bisphenol A type epoxy resin and dimethyl terephthalate were added to a reaction vessel at a molar ratio of 1:0.4. Triphenylphosphine catalyst was added at an amount of 0.2% of the total mass of the reactants. The reaction was carried out at 190℃ for 4 h.

[0068] A2. Cool the above product to 70°C and transfer it to a reactor equipped with a stirrer and nitrogen protection device. Add 10% (by weight) of epoxy resin diethyl maleate and 8% (by weight) of ethylene glycol dimethacrylate. Start stirring and control the speed at 180 r / min. Add 3% (by weight) of benzoyl peroxide to the reaction system. Under nitrogen protection, heat to 90°C and react for 5 h. After the reaction is completed, cool to room temperature and perform vacuum distillation at 55°C and -0.09 MPa to remove unreacted monomers and small molecule byproducts.

[0069] A3. Add 6% by weight of glycidyl methacrylate to the reaction system, react at 100℃ for 1.5 h, and cool to room temperature to obtain modified bisphenol A type epoxy resin.

[0070] The preparation method of nano-silica includes the following steps:

[0071] B1. Nano-silica was added to a 6% (w / w) solution of 3-aminopropyltriethoxysilane in ethanol, with a mass ratio of nano-silica to solution of 1:15. The mixture was stirred at 55°C for 3.5 h. After the reaction was completed, the mixture was centrifuged, washed four times with ethanol, and dried under vacuum at 85°C for 7 h to obtain surface-aminated nano-silica.

[0072] B2. Surface-aminated nano-silica was dispersed in anhydrous toluene to form a suspension with a mass fraction of 6%. 18% of the mass of nano-silica and 9,10-diphenylethynyl anthracene were added to the suspension, along with 2% of the mass of 9,10-diphenylethynyl anthracene as a catalyst. The mixture was refluxed for 10 h under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature, centrifuged, washed sequentially with toluene and anhydrous ethanol, and dried under vacuum at 100 °C for 9 h.

[0073] B3. Add the above-treated nano-silica to an ethanol solution of tetraethyl orthosilicate. The mass ratio of tetraethyl orthosilicate to nano-silica is 1.5:1, and the mass fraction of tetraethyl orthosilicate in the ethanol solution is 13%. Then, add ammonia water to adjust the pH of the solution to 9. Stir the reaction at room temperature for 14 h. After the reaction is completed, centrifuge, wash with ethanol, and vacuum dry at 85°C for 7 h.

[0074] B4. The core-shell structured nano-silica was dispersed in a mixed solution of ethanol and deionized water at a volume ratio of 3:1 to form a suspension with a mass fraction of 6%. A mixed aqueous solution of cerium nitrate and lanthanum nitrate was added to the suspension, wherein the molar ratio of cerium nitrate to lanthanum nitrate was 3:1, and the total amount of rare earth elements added was 3% of the mass of nano-silica. The pH value was adjusted to 10 with ammonia water, and the reaction was stirred at 65℃ for 7 h. After the reaction was completed, the nano-silica was separated by centrifugation, washed with deionized water, vacuum dried at 125℃ for 11 h, and finally calcined at 420℃ for 2.5 h to obtain modified nano-silica.

[0075] A method for preparing a high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material includes the following steps:

[0076] S1. The modified nano-silica was dried in a vacuum drying oven at 140°C for 5 h, and the high-purity methyltetrahydrophthalic anhydride was heated until it melted.

[0077] S2. Weigh the modified bisphenol A epoxy resin, molten methyltetrahydrophthalic anhydride, and solvent according to the weight proportions, add them to a reaction vessel equipped with a stirring device and heating function, and stir at 180 r / min for 35 min at 75℃ to obtain the resin mixture.

[0078] S3. Add the modified nano-silica, light stabilizer, coupling agent, accelerator and antioxidant to the resin mixture in sequence, heat to 90℃, and continue stirring at 280 r / min for 45 min to obtain the mixture.

[0079] S4. Transfer the mixture to a vacuum degassing machine and degas for 20 min under a vacuum of -0.09 MPa, then raise the temperature to 55℃ and degas for 15 min under vacuum.

[0080] S5. Quickly inject the degassed material into a mold preheated to 90°C, pre-cur it at 100°C for 2 hours, then raise the temperature to 170°C and cure it for 4 hours. Allow it to cool naturally to room temperature before demolding to obtain the high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material. Example 3

[0081] A high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material comprises the following raw materials in parts by weight:

[0082] The mixture contains 60 parts of modified bisphenol A epoxy resin, 50 parts of methyltetrahydrophthalic anhydride, 15 parts of modified nano-silica, 2 parts of light stabilizer, 5 parts of coupling agent, 1 part of accelerator, 0.3 parts of antioxidant, and 10 parts of solvent.

[0083] The light stabilizer is UV-326.

[0084] The coupling agent is a titanate coupling agent.

[0085] The accelerator is benzyltriethylammonium chloride.

[0086] The antioxidant is DSTDP.

[0087] The solvent is ethyl acetate.

[0088] The preparation method of modified bisphenol A epoxy resin includes the following steps:

[0089] A1. Bisphenol A type epoxy resin and dimethyl terephthalate were added to a reaction vessel at a molar ratio of 1:0.5. Triphenylphosphine catalyst was added at a rate of 0.3% of the total mass of the reactants. The reaction was carried out at 200℃ for 5 h.

[0090] A2. Cool the above product to 80°C and transfer it to a reactor equipped with a stirrer and nitrogen protection device. Add 12% (by weight) of epoxy resin diethyl maleate and 10% (by weight) of ethylene glycol dimethacrylate. Start stirring and control the speed at 200 r / min. Add 3% (by weight) of benzoyl peroxide to the reaction system. Under nitrogen protection, heat to 100°C and react for 6 h. After the reaction is completed, cool to room temperature and perform vacuum distillation at 60°C and -0.1 MPa to remove unreacted monomers and small molecule byproducts.

[0091] A3. Add 8% by weight of glycidyl methacrylate to the reaction system, react at 110℃ for 2 h, and cool to room temperature to obtain modified bisphenol A type epoxy resin.

[0092] The preparation method of nano-silica includes the following steps:

[0093] B1. Add nano-silica to a 10% (w / w) 3-aminopropyltriethoxysilane ethanol solution, with a mass ratio of nano-silica to solution of 1:20. Stir and react at 60°C for 4 h. After the reaction is complete, centrifuge, wash with ethanol 5 times, and vacuum dry at 90°C for 8 h to obtain surface-aminated nano-silica.

[0094] B2. Surface-aminated nano-silica was dispersed in anhydrous toluene to form a suspension with a mass fraction of 8%. 20% of the mass of nano-silica and 9,10-diphenylethynyl anthracene were added to the suspension. At the same time, 3% of the mass of 9,10-diphenylethynyl anthracene and 4-dimethylaminopyridine catalyst were added. The reaction was refluxed for 12 h under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature, centrifuged, washed with toluene and anhydrous ethanol in sequence, and dried under vacuum at 110 °C for 10 h.

[0095] B3. Add the nano-silica treated above to an ethanol solution of tetraethyl orthosilicate, with a mass ratio of tetraethyl orthosilicate to nano-silica of 2:1 and a mass fraction of tetraethyl orthosilicate in the ethanol solution of 15%. Then add ammonia to adjust the pH of the solution to 10, stir the reaction at room temperature for 16 h, centrifuge after the reaction is completed, wash with ethanol, and vacuum dry at 90 °C for 8 h.

[0096] B4. The core-shell structured nano-silica was dispersed in a mixed solution of ethanol and deionized water at a volume ratio of 3:1 to form a suspension with a mass fraction of 10%. A mixed aqueous solution of cerium nitrate and lanthanum nitrate was added to the suspension, wherein the molar ratio of cerium nitrate to lanthanum nitrate was 3:1, and the total amount of rare earth elements added was 5% of the mass of nano-silica. The pH value was adjusted to 10 with ammonia water, and the reaction was stirred at 70℃ for 8 h. After the reaction was completed, the nano-silica was separated by centrifugation, washed with deionized water, vacuum dried at 130℃ for 12 h, and finally calcined at 450℃ for 3 h to obtain modified nano-silica.

[0097] A method for preparing a high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material includes the following steps:

[0098] S1. The modified nano-silica was dried in a vacuum drying oven at 150°C for 6 h, and the high-purity methyltetrahydrophthalic anhydride was heated to melt.

[0099] S2. Weigh the modified bisphenol A epoxy resin, molten methyltetrahydrophthalic anhydride, and solvent according to the weight parts, add them to a reaction vessel equipped with a stirring device and heating function, and stir at 200 r / min for 40 min at 75℃ to obtain the resin mixture.

[0100] S3. Add the modified nano-silica, light stabilizer, coupling agent, accelerator and antioxidant to the resin mixture in sequence, heat to 100℃, and continue stirring at 300 r / min for 60 min to obtain the mixture.

[0101] S4. Transfer the mixture to a vacuum degassing machine and degas for 25 min under a vacuum of -0.1 MPa, then heat to 60℃ and degas under vacuum for 20 min.

[0102] S5. Quickly inject the degassed material into a mold preheated to 100°C, pre-cur it at 110°C for 2 hours, then raise the temperature to 170°C and cure it for 5 hours. Allow it to cool naturally to room temperature before demolding to obtain the high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material.

[0103] Comparative Example 1: Bisphenol A type epoxy resin and nano silica were not modified, and the rest of the process was the same as in Example 1.

[0104] Comparative Example 2: Nano-silica is not modified, and the remaining processes are the same as in Example 1.

[0105] Comparative Example 3: Bisphenol A type epoxy resin was not modified, and the rest of the process was the same as in Example 1.

[0106] Experimental example:

[0107] The light transmittance, tensile strength, elongation at break and heat distortion temperature of the encapsulation materials prepared in Examples 1-3 and Comparative Examples 1-3 were tested (results are shown in Table 1).

[0108] Table 1. Light transmittance test results

[0109] Group Light transmittance (%) Example 1 95.8 Example 2 95.6 Example 3 95.5 Comparative Example 1 88.2 Comparative Example 2 91.4 Comparative Example 3 93.8

[0110] Table 2. Test results of tensile strength, elongation at break, and heat distortion temperature.

[0111] Group Tensile strength (MPa) Elongation at break (%) Heat distortion temperature (°C) Example 1 58.2 18.2 152 Example 2 58.6 18.5 150 Example 3 59.1 18.6 152 Comparative Example 1 42.5 12.2 132 Comparative Example 2 52.3 15.7 146 Comparative Example 3 48.6 14.2 142

[0112] As shown in the table above, the encapsulation materials of Examples 1-3 have good light transmittance, high tensile strength, elongation at break, and heat distortion temperature. The light transmittance of Comparative Example 3 is higher than that of Comparative Example 2, indicating that the modified nano-silica has a more significant effect on improving light transmittance. The tensile strength, elongation at break, and heat distortion temperature of Comparative Example 2 are higher than those of Comparative Example 3, indicating that the modified bisphenol A epoxy resin can significantly improve mechanical properties.

[0113] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material, characterized in that, Including the following parts by weight of raw materials: The mixture contains 40-60 parts of modified bisphenol A epoxy resin, 30-50 parts of methyltetrahydrophthalic anhydride, 5-15 parts of modified nano-silica, 0.5-2 parts of light stabilizer, 1-5 parts of coupling agent, 0.5-1 part of accelerator, 0.1-0.3 parts of antioxidant, and 5-10 parts of solvent. The preparation method of modified bisphenol A epoxy resin includes the following steps: A1. Add bisphenol A type epoxy resin and dimethyl terephthalate to a reaction vessel at a molar ratio of 1:0.2~0.5, add triphenylphosphine catalyst at an amount of 0.1~0.3% of the total mass of the reactants, and react at 180~200℃ for 3~5 h. A2. Cool the above product to 60-80℃, transfer it to a reactor equipped with a stirrer and nitrogen protection device, add 8-12% (by weight) of epoxy resin diethyl maleate and 6-10% (by weight) of ethylene glycol dimethacrylate, start stirring, and control the speed at 150-200 r / min. Add 3% (by weight) of benzoyl peroxide to the reaction system. Under nitrogen protection, heat to 90-100℃ and react for 4-6 h. After the reaction is completed, cool to room temperature and perform vacuum distillation at 50-60℃ and a vacuum of -0.08 to -0.1 MPa to remove unreacted monomers and small molecule byproducts. A3. Add 3-8% by weight of glycidyl methacrylate to the reaction system, react at 90-110℃ for 1-2 h, and cool to room temperature to obtain modified bisphenol A type epoxy resin.

2. The high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material according to claim 1, characterized in that, The preparation method of nano-silica includes the following steps: B1. Add nano-silica to a 5-10% (w / w) 3-aminopropyltriethoxysilane ethanol solution, with a mass ratio of nano-silica to solution of 1:10-20. Stir and react at 50-60℃ for 3-4 h. After the reaction is complete, centrifuge, wash with ethanol 3-5 times, and vacuum dry at 80-90℃ for 6-8 h to obtain surface-aminated nano-silica. B2. Surface-aminated nano-silica is dispersed in anhydrous toluene to form a suspension with a mass fraction of 5-8%. 15-20% of the mass of 9,10-diphenylethynyl anthracene nano-silica is added to the suspension, along with 1-3% of the mass of 9,10-diphenylethynyl anthracene catalyst. The mixture is refluxed under nitrogen protection for 8-12 h. After the reaction is complete, it is cooled to room temperature, centrifuged, washed sequentially with toluene and anhydrous ethanol, and vacuum dried at 100-110℃ for 8-10 h. B3. Add the above-treated nano-silica to an ethanol solution of tetraethyl orthosilicate, with a mass ratio of tetraethyl orthosilicate to nano-silica of 1~2:1 and a mass fraction of tetraethyl orthosilicate in the ethanol solution of 10~15%. Then add ammonia to adjust the pH of the solution to 9~10, stir the reaction at room temperature for 12~16 h, centrifuge after the reaction is completed, wash with ethanol, and vacuum dry at 80~90℃ for 6~8 h. B4. The core-shell structured nano-silica is dispersed in a mixed solution of ethanol and deionized water at a volume ratio of 3:1 to form a suspension with a mass fraction of 5-10%. A mixed aqueous solution of cerium nitrate and lanthanum nitrate is added to the suspension, wherein the molar ratio of cerium nitrate to lanthanum nitrate is 3:1, and the total amount of rare earth elements added is 2-5% of the mass of nano-silica. The pH value is adjusted to 9-10 with ammonia water, and the reaction is stirred at 60-70℃ for 6-8 h. After the reaction is completed, the mixture is centrifuged, washed with deionized water, vacuum dried at 120-130℃ for 10-12 h, and finally calcined at 400-450℃ for 2-3 h to obtain modified nano-silica.

3. The high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material according to claim 1, characterized in that, The light stabilizer is one of GW-540, UV-9, or UV-326.

4. The high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material according to claim 1, characterized in that, The coupling agent is one of KH-550, KH-560, or titanate coupling agent.

5. The high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material according to claim 1, characterized in that, The accelerator is one of 2-methylimidazole, boron trifluoride diethyl ether complex, or benzyltriethylammonium chloride.

6. The high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material according to claim 1, characterized in that, The antioxidant is one of 1010, 168, or DSTDP.

7. The high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material according to claim 1, characterized in that, The solvent is one of toluene, acetone, or ethyl acetate.

8. A method for preparing a high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Place the modified nano-silica in a vacuum drying oven at 120~150℃ and dry for 4~6 h, and heat the high-purity methyltetrahydrophthalic anhydride until it melts; S2. Weigh the modified bisphenol A epoxy resin, molten methyltetrahydrophthalic anhydride, and solvent according to the weight proportions, add them to a reaction vessel equipped with a stirring device and heating function, and stir at 70~75℃ and a speed of 150~200 r / min for 30~40 min to form a resin mixture. S3. Add the modified nano-silica, light stabilizer, coupling agent, accelerator and antioxidant to the resin mixture in sequence, heat to 80~100℃, and continue stirring at 250~300 r / min for 30~60 min to obtain the mixture. S4. Transfer the mixture to a vacuum degassing machine and degas for 20-25 minutes under a vacuum of -0.09 to -0.1 MPa, then raise the temperature to 50-60℃ and degas for 15-20 minutes. S5. Quickly inject the degassed material into a mold preheated to 90~100℃, pre-cur it at 100~110℃ for 1.5~2 h, then raise the temperature to 160~170℃ and cure it for 3~5 h. Allow it to cool naturally to room temperature before demolding to obtain the high-transmittance diode methyltetrahydrophthalic anhydride encapsulation material.