Photoresist for optical waveguide and preparation method thereof

Abstract

The present application relates to the field of photoresists, and in particular to a photoresist for optical waveguides and a preparation method thereof. For optical waveguide photoresists, the raw materials are, by mass, 40 to 70 parts of epoxy resin composition, 10 to 30 parts of toughening agent, 2 to 5 parts of photoinitiator, 0.1 to 1 part of defoamer, 0.5 to 5 parts of coupling agent, 1 to 5 parts of antioxidant, 0.5 to 2 parts of thermal stabilizer, and 30 to 50 parts of solvent. The optical waveguide photoresist finally prepared by the present application can not only effectively reduce light loss, but also has excellent thermal stability, weather resistance and water resistance of optical waveguide materials, and its glass transition temperature is high, which can effectively make up for the vacancy in the field of high-end photoresists in my country, meet the performance requirements of existing high-end technology industries such as precision devices, photonic crystals, and micro medical devices, and has very excellent application prospects.

Description

Technical Field

[0001] The present application relates to the field of photoresists, and in particular to a photoresist for optical waveguides and a preparation method thereof. Background Art

[0002] In the field of chip manufacturing, photolithography is one of the most important equipment. When we use photolithography to process the surface of semiconductor materials, if we use appropriate selective photoresists, we can get the required image on the surface. For example, in the process of making chips, we cover the silicon wafer with a layer of highly photosensitivity photoresist, then use ultraviolet light through the mask to irradiate the silicon wafer, and then use a specific developer to wash the photoresist on the silicon wafer, so that the circuit diagram can be transferred from the mask to the silicon wafer. This is a very important step in chip manufacturing.

[0003] In recent years, as the industry demand for photolithography in the production and manufacturing of precision devices, micro-nano optical components such as photonic crystals, and micro-medical devices such as microneedles and biochips continues to expand, the global demand for photoresist is also increasing.

[0004] At present, in the field of photoresist, the photoresist produced in China is mainly PCB photoresist, which is used for printed circuit boards. However, in the field of high-end semiconductor photoresist with high technical content, there is a big gap with the global advanced level. In addition, the existing semiconductor photoresist products have problems such as high loss, poor thermal stability, low glass transition temperature, poor weather resistance, and poor water resistance. As a key material in the integrated circuit industry, the technical barriers of the photoresist industry are extremely high. Moreover, it must develop in coordination with the photolithography machine. Therefore, it is of far-reaching significance to achieve domestic independence in photoresist.

[0005] Therefore, in order to solve the above problems, the present application provides a photoresist for optical waveguides and a preparation method thereof. The optical waveguide photoresist finally prepared by the present application can not only effectively reduce light loss, but also has excellent thermal stability, weather resistance and water resistance of optical waveguide materials, and its glass transition temperature is high. It can effectively make up for the gap in my country's high-end photoresist field and meet the performance requirements of existing high-end technology industries such as precision devices, photonic crystals, and micro medical devices, and has very excellent application prospects. Summary of the invention

[0006] In order to solve the above problems, the first aspect of the present application provides a photoresist for optical waveguides, wherein the raw materials are, by mass: 40 to 70 parts of epoxy resin composition, 10 to 30 parts of toughening agent, 2 to 5 parts of photoinitiator, 0.1 to 1 part of defoaming agent, 0.5 to 5 parts of coupling agent, 1 to 5 parts of antioxidant, 0.5 to 2 parts of thermal stabilizer, and 30 to 50 parts of solvent.

[0007] As a preferred solution, the epoxy resin composition is a composition of bisphenol A epoxy resin, block polymerized epoxy resin and modified bisphenol A epoxy resin.

[0008] As a preferred solution, the mass ratio of the bisphenol A epoxy resin, the block polymerized epoxy resin and the modified bisphenol A epoxy resin is (40-45): (2-5): (6-10).

[0009] As a preferred solution, the epoxy equivalent of the bisphenol A epoxy resin is 185-195 g / eq.

[0010] As a preferred solution, the viscosity of the bisphenol A epoxy resin is 14000-16000 mPa·s, and the temperature condition is 25°C.

[0011] As a preferred solution, the block polymerized epoxy resin is a block polymerized resin of ethylene oxide-propylene oxide.

[0012] As a preferred solution, the weight average molecular weight of the block polymerized epoxy resin is 1500-2000 Da.

[0013] As a preferred scheme, the preparation method of the modified bisphenol A epoxy resin comprises the following steps: S1: heating the bisphenol A epoxy resin to 70-80°C, then stirring at a speed of 80-100 rpm and adding phenyl glycidyl ether, isobornyl acrylate and benzoyl peroxide, stirring for 20-30 minutes to obtain a premix; S2: adding perfluoroalkyl ethyl acrylate, isophorone diamine and 2,4,6-tris(dimethylaminomethyl)phenol to the premix, heating to 120-140°C, and keeping the temperature for reaction for 10-12 hours; S3: after the reaction is completed, naturally cooling to room temperature, adding triethanolamine to adjust the pH to 7.5-8, then pouring the product into a vacuum degassing machine, evacuating to -0.1-0.2 MPa, keeping for 15-20 minutes, and obtaining the product after completion.

[0014] In the present application, the bisphenol A type epoxy resin used in the modified bisphenol A type epoxy resin is the same as the bisphenol A type epoxy resin in the epoxy resin composition.

[0015] As a preferred solution, the mass ratio of the bisphenol A epoxy resin, phenyl glycidyl ether and isobornyl acrylate is (6-8): (1.5-2): (0.3-0.4).

[0016] As a preferred solution, the mass ratio of the perfluoroalkylethyl acrylate, isophoronediamine, 2,4,6-tris(dimethylaminomethyl)phenol and the premix is ​​(3-4):(0.4-0.5):(0.2-0.25):(10-15).

[0017] In the present application, by adopting the scheme of the epoxy resin composition containing the modified bisphenol A epoxy resin and the block polymerized epoxy resin, the thermal stability, weather resistance and water resistance of the photoresist can be greatly improved, and the glass transition temperature can be improved. The added modified bisphenol A epoxy resin can rely on the added block polymerized epoxy resin as a good auxiliary carrier to greatly improve its dispersion effect in the epoxy resin system, and the block polymerized epoxy resin can form a stable interface film between the composition raw materials. The presence of the film can effectively inhibit the mutual dislocation and slippage phenomenon of the molecular chain segment network inside the photoresist system, thereby enhancing and ensuring the molecular chain cross-linking strength, stabilizing the stability of the internal network, and then being able to show good internal impedance under various environments, and obtain excellent weather resistance, heat resistance and water resistance.

[0018] On the other hand, the addition of modified bisphenol A epoxy resin can increase the interaction between internal molecular segments while maintaining better internal structural integrity under harsh environments through the introduction of fluoroalkyl segments, rigid segments and multiple cross-linking sites in its chain segments. The interpenetrating network structure formed greatly improves the impedance effect of the photoresist to the external environment, thereby achieving comprehensive performance improvement.

[0019] As a preferred solution, the mass ratio of the epoxy resin composition, the toughening agent and the coupling agent is (50-60): (18-22): (1-4).

[0020] As a preferred solution, the mass ratio of the epoxy resin composition, the toughening agent and the coupling agent is 55:20:1.

[0021] As a preferred solution, the toughening agent is at least one of polypropylene glycol diglycidyl ether, polymethyl methacrylate, polyurethane and styrene-butadiene block copolymer.

[0022] As a preferred solution, the toughening agent is polypropylene glycol diglycidyl ether.

[0023] As a preferred solution, the photoinitiator is any one of the cationic photoinitiators.

[0024] As a preferred solution, the defoaming agent is at least one of silicone defoaming agents.

[0025] As a preferred solution, the defoaming agent is any one of BYK 066N, BYK-141 and BYK-A530.

[0026] As a preferred solution, the coupling agent is at least one of aminosilane coupling agents.

[0027] As a preferred solution, the coupling agent is at least one of γ-glycidyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.

[0028] As a preferred solution, the coupling agent is γ-glycidyloxypropyltrimethoxysilane.

[0029] As a preferred solution, the antioxidant is at least one of Irganox L57, Irganox 1010, Irganox 1076, Irganox 1098, DPDP and DLTP.

[0030] As a preferred solution, the antioxidant is Irganox L57 or DPDP.

[0031] As a preferred solution, the antioxidant is a composition of Irganox L57 and DPDP, and the mass ratio of the two is (1-4): (1-4).

[0032] As a preferred solution, the heat stabilizer is at least one of triphenyl phosphite, diphenyl isodecyl phosphite, trinonylphenyl phosphite and polydimethylsiloxane.

[0033] As a preferred solution, the heat stabilizer is triphenyl phosphite.

[0034] As a preferred solution, the solvent is a combination of γ-butyrolactone and propylene carbonate.

[0035] As a preferred solution, the mass ratio of γ-butyrolactone to propylene carbonate is (2-4): (0.5-1.5).

[0036] The second aspect of the present application provides a method for preparing the above-mentioned optical waveguide photoresist, which specifically comprises the following steps: S1: adding an epoxy resin composition and a toughening agent to a reaction container, heating the mixture to 75-85°C, mixing and stirring at a speed of 600-800 rpm for 25-30 minutes, and then naturally cooling to room temperature to obtain a mixture I; S2: adding a solvent, a defoaming agent, a coupling agent, an antioxidant and a heat stabilizer to the mixture I in sequence, mixing and stirring at a speed of 600-800 rpm for 3-5 minutes each time, and mixing and stirring at a speed of 600-800 rpm for 25-30 minutes after all are added, and after being completely mixed, a mixture ⅠⅠ is obtained; S3: adding a photoinitiator to the mixture ⅠⅠ in a light-proof environment, stirring at a speed of 600-800 rpm for 25-30 minutes at room temperature, and then reducing the speed to 50-60 rpm, and vacuuming for 20-30 minutes while stirring, and the mixture is obtained after completion.

[0037] The beneficial effects of this application are:

[0038] 1. The photoresist for optical waveguide provided in the present application can not only effectively reduce light loss, but also has excellent thermal stability, weather resistance and water resistance of optical waveguide materials, and its glass transition temperature is high, which meets the performance requirements of existing high-end technology industries such as precision devices, photonic crystals, and micro medical devices, and has very excellent application prospects.

[0039] 2. The optical waveguide photoresist provided in the present application can greatly improve its dispersion effect in the epoxy resin system by adding modified bisphenol A epoxy resin and relying on the added block polymerized epoxy resin as a good auxiliary carrier. At the same time, the block polymerized epoxy resin can form a stable interface film between the raw materials of the composition. The presence of the film can effectively inhibit the mutual dislocation and slippage of the molecular chain segment network inside the photoresist system, thereby enhancing and ensuring the cross-linking strength of the molecular chain, stabilizing the stability of the internal network, and then being able to exhibit good internal impedance in a variety of environments, thereby obtaining excellent weather resistance, heat resistance and water resistance.

[0040] 3. The photoresist for optical waveguide provided in the present application can increase the interaction between internal molecular segments while maintaining better internal structural integrity under harsh environments by adding modified bisphenol A epoxy resin through the introduction of fluoroalkyl segments, rigid segments and multiple cross-linking sites in its segments. The interpenetrating network structure formed greatly improves the impedance effect of the photoresist to the external environment, thereby achieving comprehensive performance improvement. DETAILED DESCRIPTION

[0041] The following will further explain and demonstrate the technical solutions in the above invention content of this application in the form of specific implementation schemes. The following embodiments are only practical examples used to illustrate and explain the contents of the technical solutions in the specification, and should not limit the scope of the claims to be protected by this application. All technical products based on the technical solutions described in the invention content of this application should be included in the scope to be protected by this application.

[0042] In the following examples, unless otherwise specified, the raw materials are all commercially available products, or can be prepared by methods well known to those skilled in the art.

[0043] Example 1

[0044] Embodiment 1 The first aspect provides a photoresist for optical waveguides, wherein the raw materials are, by mass: 55 parts of epoxy resin composition, 20 parts of toughening agent, 2 parts of photoinitiator, 0.2 parts of defoaming agent, 1 part of coupling agent, 5 parts of antioxidant, 0.5 parts of thermal stabilizer, and 45 parts of solvent.

[0045] The epoxy resin composition is a composition of bisphenol A epoxy resin, block polymerized epoxy resin and modified bisphenol A epoxy resin, and the mass ratio of the three is 45:3:7.

[0046] The epoxy equivalent of bisphenol A epoxy resin is 190 g / eq, the viscosity is 15000 mPa·s, the temperature condition is 25° C., and the product model Araldite® GT 7072 sold by Huntsman Corporation in the United States was purchased.

[0047] The block polymerized epoxy resin is a block polymerized resin of ethylene oxide-propylene oxide, has a weight average molecular weight of 1600 Da, and is purchased from the L42 model product sold by BASF in Germany.

[0048] The preparation method of modified bisphenol A epoxy resin comprises the following steps: S1: heating 7.5 parts of bisphenol A epoxy resin to 80°C, then stirring at a speed of 100 rpm and adding 1.8 parts of phenyl glycidyl ether, 0.36 parts of isobornyl acrylate and 0.04 parts of benzoyl peroxide, and stirring for 25 minutes to obtain a premix; S2: adding 3.2 parts of perfluoroalkyl ethyl acrylate, 0.42 parts of isophorone diamine and 0.22 parts of 2,4,6-tris(dimethylaminomethyl)phenol to 13.6 parts of the premix, heating to 125°C, and keeping the temperature for reaction for 11 hours; S3: naturally cooling to room temperature after the reaction is completed, adding triethanolamine to adjust the pH to 7.8, and then pouring the product into a vacuum degassing machine, evacuating to -0.1 MPa, and keeping for 15 minutes, and obtaining the product after completion.

[0049] The bisphenol A type epoxy resin used in the modified bisphenol A type epoxy resin is the same as the bisphenol A type epoxy resin in the epoxy resin composition.

[0050] The toughening agent is polypropylene glycol diglycidyl ether, which is purchased from the Dow Chemical Company of the United States and is a product of model DER736.

[0051] The photoinitiator is a cationic photoinitiator, which is purchased from Sartomer of France and is a Speedcure 992 product.

[0052] The defoamer is silicone defoamer BYK-066N.

[0053] The coupling agent is γ-glycidyloxypropyltrimethoxysilane, which is purchased from the Silquest A-187 product sold by Momentive High-Tech Materials, Inc. in the United States.

[0054] The antioxidant is a combination of Irganox L57 and DPDP, and the mass ratio of the two is 4:1.

[0055] The heat stabilizer is triphenyl phosphite.

[0056] The solvent is a composition of gamma-butyrolactone and propylene carbonate, and the mass ratio of the two is 4:0.5.

[0057] The second aspect of the present application provides a method for preparing the above-mentioned optical waveguide photoresist, which specifically includes the following steps: S1: adding an epoxy resin composition and a toughening agent to a reaction container, heating to 80°C, mixing and stirring at a speed of 720rpm for 30min, and then naturally cooling to room temperature to obtain a mixture I; S2: adding a solvent, a defoamer, a coupling agent, an antioxidant and a heat stabilizer to the mixture I in sequence, mixing and stirring at a speed of 720rpm for 4min each time, and mixing and stirring at a speed of 720rpm for 30min after all are added, and after being completely mixed, a mixture ⅠⅠ is obtained; S3: adding a photoinitiator to the mixture ⅠⅠ in a light-proof environment, stirring at a speed of 720rpm for 30min at room temperature, and then reducing the speed to 50rpm, and vacuuming for 25min while stirring, and the mixture is obtained after completion.

[0058] Example 2

[0059] The specific implementation of this embodiment is basically the same as that of Example 1, with the only difference being that for optical waveguide photoresist, the raw materials, in parts by mass, are: 40 parts of epoxy resin composition, 30 parts of toughening agent, 3 parts of photoinitiator, 0.5 parts of defoaming agent, 2 parts of coupling agent, 5 parts of antioxidant, 1 part of thermal stabilizer, and 35 parts of solvent.

[0060] The solvent is a composition of gamma-butyrolactone and propylene carbonate, and the mass ratio of the two is 2:1.5.

[0061] The antioxidant was Irganox L57.

[0062] Example 3

[0063] The specific implementation of this embodiment is basically the same as that of Example 1, with the only difference being that for optical waveguide photoresist, the raw materials, in parts by mass, are: 70 parts of epoxy resin composition, 10 parts of toughening agent, 4 parts of photoinitiator, 0.8 parts of defoaming agent, 3 parts of coupling agent, 5 parts of antioxidant, 1.5 parts of thermal stabilizer, and 40 parts of solvent.

[0064] The solvent is a composition of gamma-butyrolactone and propylene carbonate, and the mass ratio of the two is 3:1.

[0065] The antioxidant is a combination of Irganox L57 and DPDP, and the mass ratio of the two is 3:2.

[0066] Example 4

[0067] The specific implementation of this embodiment is basically the same as that of Embodiment 1, except that: for optical waveguide photoresist, the raw materials, by mass, are: 55 parts of epoxy resin composition, 20 parts of toughening agent, 5 parts of photoinitiator, 0.8 parts of defoaming agent, 4 parts of coupling agent, 5 parts of antioxidant, 1.5 parts of thermal stabilizer, and 45 parts of solvent.

[0068] The solvent is a composition of gamma-butyrolactone and propylene carbonate, and the mass ratio of the two is 3:1.5.

[0069] The antioxidant is a composite of Irganox L57 and DPDP, and the mass ratio of the two is 1:4.

[0070] Example 5

[0071] The specific implementation of this embodiment is basically the same as that of Example 1, with the only difference being that for optical waveguide photoresist, the raw materials, in parts by mass, are: 40 parts of epoxy resin composition, 30 parts of toughening agent, 3 parts of photoinitiator, 0.5 parts of defoaming agent, 5 parts of coupling agent, 5 parts of antioxidant, 0.5 parts of thermal stabilizer, and 30 parts of solvent.

[0072] The solvent is a composition of gamma-butyrolactone and propylene carbonate, and the mass ratio of the two is 2:1.

[0073] The antioxidant is DPDP.

[0074] Example 6

[0075] The specific implementation of this embodiment is basically the same as that of Embodiment 1, except that: for optical waveguide photoresist, the raw materials, by mass, are: 70 parts of epoxy resin composition, 10 parts of toughening agent, 2 parts of photoinitiator, 0.2 parts of defoaming agent, 1 part of coupling agent, 5 parts of antioxidant, 1 part of thermal stabilizer, and 45 parts of solvent.

[0076] The solvent is a composition of gamma-butyrolactone and propylene carbonate, and the mass ratio of the two is 4:0.5.

[0077] The antioxidant is a composite of Irganox L57 and DPDP, and the mass ratio of the two is 2:3.

[0078] Comparative Example 1

[0079] The specific implementation of this comparative example is basically the same as that of Example 1, except that: for optical waveguide photoresist, the raw materials, by mass, are: 70 parts of epoxy resin composition, 3 parts of photoinitiator, 0.8 parts of defoaming agent, 2 parts of coupling agent, 5 parts of antioxidant, and 40 parts of solvent.

[0080] The solvent is a composition of gamma-butyrolactone and propylene carbonate, and the mass ratio of the two is 3:1.

[0081] The antioxidant is a combination of Irganox L57 and DPDP, and the mass ratio of the two is 4:1.

[0082] The epoxy equivalent of bisphenol A epoxy resin is 170 g / eq, the viscosity is 11000 mPa·s, the temperature condition is 25° C., and the Epikote 828 model product sold by Hanson Corporation of the United States was purchased.

[0083] Comparative Example 2

[0084] The specific implementation of this comparative example is basically the same as that of Example 1, except that: for optical waveguide photoresist, the raw materials, by mass, are: 40 parts of epoxy resin composition, 30 parts of toughening agent, 2 parts of photoinitiator, 0.2 parts of defoaming agent, 3 parts of coupling agent, and 30 parts of solvent.

[0085] The solvent is a composition of gamma-butyrolactone and propylene carbonate, and the mass ratio of the two is 3:1.

[0086] The epoxy equivalent of bisphenol A epoxy resin is 170 g / eq, the viscosity is 11000 mPa·s, the temperature condition is 25° C., and the Epikote 828 model product sold by Hanson Corporation of the United States was purchased.

[0087] Comparative Example 3

[0088] The specific implementation of this comparative example is basically the same as that of Example 1, except that the epoxy resin composition is a composition of bisphenol A epoxy resin, block polymerized epoxy resin and modified bisphenol A epoxy resin, and the mass ratio of the three is 52:2:1.

[0089] Comparative Example 4

[0090] The specific implementation of this comparative example is basically the same as that of Example 1, except that: the preparation method of modified bisphenol A epoxy resin comprises the following steps: S1: heating 15 parts of bisphenol A epoxy resin to 80°C, then stirring at a speed of 100 rpm and adding 0.6 parts of phenyl glycidyl ether, 0.16 parts of isobornyl acrylate and 0.02 parts of benzoyl peroxide, stirring for 25 minutes to obtain a premix; S2: adding 3.2 parts of perfluoroalkyl ethyl acrylate, 0.42 parts of isophorone diamine and 0.22 parts of 2,4,6-tris(dimethylaminomethyl)phenol to 13.6 parts of the premix, heating to 125°C, and keeping the temperature for reaction for 11 hours; S3: after the reaction is completed, naturally cooling to room temperature, adding triethanolamine to adjust the pH to 7.8, then pouring the product into a vacuum degassing machine, evacuating to -0.1 MPa, keeping for 15 minutes, and obtaining the product after completion.

[0091] Comparative Example 5

[0092] The specific implementation of this comparative example is basically the same as that of Example 1, except that: the preparation method of modified bisphenol A epoxy resin comprises the following steps: S1: heating 7.5 parts of bisphenol A epoxy resin to 80°C, then stirring at a speed of 100 rpm and adding 1.8 parts of phenyl glycidyl ether, 0.36 parts of isobornyl acrylate and 0.04 parts of benzoyl peroxide, stirring for 25 minutes to obtain a premix; S2: adding 1.5 parts of perfluoroalkyl ethyl acrylate, 0.22 parts of isophorone diamine and 0.14 parts of 2,4,6-tris(dimethylaminomethyl)phenol to 28.5 parts of the premix, heating to 125°C, and keeping the temperature for reaction for 11 hours; S3: after the reaction is completed, naturally cooling to room temperature, adding triethanolamine to adjust the pH to 7.8, then pouring the product into a vacuum degassing machine, evacuating to -0.1 MPa, keeping for 15 minutes, and obtaining the product after completion.

[0093] Comparative Example 6

[0094] The specific implementation of this comparative example is basically the same as that of Example 1, except that the block polymerized epoxy resin is a block polymerized resin of ethylene oxide-propylene oxide, having a weight average molecular weight of 10,000 Da, and is purchased from the L88 model product sold by BASF in Germany.

[0095] Performance Evaluation

[0096] Sample preparation:

[0097] 1. Prepare a wafer and place it on the spin coater.

[0098] 2. Drop 3.5 g of the photoresist prepared in the embodiment and comparative example into the center of the wafer.

[0099] 3. Turn on the spin coater, set the speed to 1500 rpm, and spin coat for 5 minutes.

[0100] 4. Put on the cover.

[0101] 5. UV light irradiation, irradiation energy ≥ 3000mj.

[0102] 6. Remove the uncured optical waveguide photoresist.

[0103] 7. Add 2.5g of cladding photoresist.

[0104] 8. Turn on the spin coater, set the speed to 1500 rpm, and spin coat for 5 minutes.

[0105] 9. UV light irradiation, irradiation energy ≥ 3000mj.

[0106] 10. Cover with the layered plate and the sample is ready.

[0107] 1. The optical loss of optical waveguide photoresist was measured using a fiber loss tester, and the numerical result was the average of 10 tests.

[0108] 2. The water boiling method is used to test the water and heat resistance stability of the optical waveguide photoresist. It is boiled in water at 80℃ for 240h. If the glue does not crack on the wafer and the glue color does not change, it is considered qualified. Otherwise, it is considered unqualified. 50 groups of samples are tested in each group, and the sample qualification rate is recorded.

[0109] 3. The glass transition temperature of optical waveguide photoresist was measured by DSC, and the numerical result was the average of 10 tests.

[0110] 4. The weather resistance of the optical waveguide photoresist is tested by the high and low temperature impact method: -40℃~120℃ high and low temperature impact for 1000h, the glue does not crack on the wafer; -40℃~120℃ high and low temperature cycle for 1000h, the glue does not crack on the wafer; 85℃, 85% high temperature and high humidity for 1000h, the glue does not crack on the wafer. If the above conditions are met, it is recorded as qualified, otherwise it is unqualified. 50 groups of samples are tested in each group, and the sample qualification rate is recorded.

[0111] Table 1 Performance test results

[0112]

[0113] It can be seen from the examples and comparative examples of the present application and the data results in Table 1 that examples 1 and 4 of the present application have obvious advantages over other examples and comparative examples in terms of optical loss, weather resistance, water resistance, heat resistance and other properties. This is mainly because the addition of the epoxy resin composition and other matching schemes specified in the present application is the result of the combined effect. The addition of modified bisphenol A epoxy resin can increase the internal molecular segment force while maintaining better internal structural integrity under a hostile environment through the introduction of fluoroalkyl segments, rigid segments and multiple cross-linking sites in its segments. The interpenetrating network structure formed greatly improves the impedance effect of the photoresist to the external environment, thereby achieving comprehensive performance improvement. For this reason, examples 1 and 4 can obtain the best performance results under the optimal ratio.

Claims

1. A photoresist for optical waveguides, characterized in that: The raw materials are as follows: 40-70 parts of epoxy resin composition, 10-30 parts of toughening agent, 2-5 parts of photoinitiator, 0.1-1 parts of defoaming agent, 0.5-5 parts of coupling agent, 1-5 parts of antioxidant, 0.5-2 parts of heat stabilizer, and 30-50 parts of solvent. The epoxy resin composition is a composition of bisphenol A epoxy resin, block polymerized epoxy resin and modified bisphenol A epoxy resin; the mass ratio of the bisphenol A epoxy resin, block polymerized epoxy resin and modified bisphenol A epoxy resin is (40-45): (2-5): (6-10); The epoxy equivalent of the bisphenol A epoxy resin is 185-195 g / eq; The viscosity of the bisphenol A epoxy resin is 14000-16000 mPa·s, and the temperature condition is 25° C.; The block polymerized epoxy resin is a block polymerized resin of ethylene oxide-propylene oxide; the weight average molecular weight of the block polymerized epoxy resin is 1500-2000Da; Preparation method of modified bisphenol A epoxy resin The following steps are involved: S1: Heat bisphenol A epoxy resin to 70-80°C, then stir at 80-100 rpm and add phenyl glycidyl ether, isobornyl acrylate and benzoyl peroxide, and stir for 20-30 minutes to obtain a premix; S2: Add perfluoroalkyl ethyl acrylate, isophorone diamine and 2,4,6-tris(dimethylaminomethyl)phenol to the premix, heat to 120-140°C, and keep warm for 10-12 hours; S3: After the reaction is completed, cool naturally to room temperature, add triethanolamine to adjust the pH to 7.5-8, then pour the product into a vacuum degassing machine, evacuate to -0.1-0.2 MPa, and keep for 15-20 minutes. After completion, the product is obtained; The mass ratio of the bisphenol A epoxy resin, phenyl glycidyl ether and isobornyl acrylate is (6-8): (1.5-2): (0.3-0.4).

2. The photoresist for optical waveguide according to claim 1, characterized in that: The mass ratio of the perfluoroalkylethyl acrylate, isophoronediamine, 2,4,6-tris(dimethylaminomethyl)phenol and the premix is ​​(3-4): (0.4-0.5): (0.2-0.25): (10-15).

3. The photoresist for optical waveguide according to claim 2, characterized in that: The mass ratio of the epoxy resin composition, the toughening agent and the coupling agent is (50-60): (18-22): (1-4).

4. The photoresist for optical waveguide according to claim 3, characterized in that: The toughening agent is at least one of polypropylene glycol diglycidyl ether, polymethyl methacrylate, polyurethane and styrene-butadiene block copolymer.

5. The photoresist for optical waveguide according to claim 4, characterized in that: The photoinitiator is any one of the cationic photoinitiators; the defoamer is at least one of the organosilicon defoamers; and the coupling agent is at least one of the aminosilane coupling agents.

6. The photoresist for optical waveguide according to claim 5, characterized in that: The antioxidant is at least one of Irganox L57, Irganox 1010, Irganox 1076, Irganox 1098, DPDP and DLTP.

7. The photoresist for optical waveguide according to claim 6, characterized in that: The thermal stabilizer is at least one of triphenyl phosphite, diphenyl isodecyl phosphite, trinonylphenyl phosphite and polydimethylsiloxane; the coupling agent is at least one of γ-glycidyloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane.

8. The photoresist for optical waveguide according to claim 7, characterized in that: The solvent is a composition of gamma-butyrolactone and propylene carbonate.

9. The photoresist for optical waveguide according to claim 8, characterized in that: The mass ratio of the γ-butyrolactone to propylene carbonate is (2-4): (0.5-1.5).

10. A method for preparing a photoresist for optical waveguide according to any one of claims 1 to 9, characterized in that: The specific steps include: S1: adding the epoxy resin composition and the toughening agent to a reaction container, heating to 75-85°C, stirring at 600-800 rpm for 25-30 min, and then naturally cooling to room temperature to obtain a mixture I; S2: adding the solvent, defoamer, coupling agent, antioxidant and heat stabilizer to the mixture I in sequence, stirring at 600-800 rpm for 3-5 min each time, and stirring at 600-800 rpm for 25-30 min after all are added, and after being completely mixed, obtaining a mixture ⅠⅠ; S3: Add photoinitiator to mixture ⅠⅠ in a light-proof environment and stir at 600~800 rpm for 25~30 min at room temperature, then reduce the speed to 50~60 rpm, and evacuate for 20~30 min while stirring.

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