A fluorine-containing acrylate polymer and a preparation method thereof, a fluorinated polymer photoresist material and applications thereof

Abstract

The application belongs to the technical field of photocured polymer optical waveguide, and provides a fluorine-containing acrylate polymer and a preparation method thereof, a fluorinated polymer photoresist material and application thereof.The fluorine-containing acrylate polymer is obtained by radical polymerization reaction of monomers; the monomers include fluorine-containing acrylate monomers and epoxy monomers; the fluorine-containing acrylate monomers are represented by structures G1 and / or G2; in G1, x is an integer of 0-10, and n is an integer of 1-15; in G2, y is an integer of 0-10, and m is an integer of 1-15.The fluorine-containing polyacrylate structure with an alkyl chain as a main structure is introduced, hydrogen atoms are replaced by fluorine atoms, the C-H bond absorption in the frequency band of optical communication is reduced, and the transmission light loss is reduced; and when the fluorine atoms are used in the fluorinated polymer photoresist material, the surface energy of the photoresist material is reduced, and the film-forming property is better than that of SU8.

Description

Technical Field

[0001] This invention relates to the field of photocurable polymer optical waveguide technology, and in particular to a fluorinated acrylate polymer and its preparation method, a fluorinated polymer photoresist material and its application. Background Technology

[0002] Photoresist is a type of polymer material sensitive to light and radiation. It is typically prepared from a polymer matrix, photoinitiator, solvent, and surfactant, and its viscosity is mainly adjusted by the ratio of the matrix material to the solvent. This type of material can be directly used to fabricate waveguide devices, microplate printed patterns, etc. The basic process for fabricating devices using photoresist is as follows: First, a layer of photoresist is coated onto a substrate (such as a glass slide, PCB, or plastic board). After pre-baking, exposure, and post-baking, a cured thin film is formed. Selective exposure using a pre-designed photomask can create various complex patterns. Finally, the uncured portions are dissolved using a developer. Optical waveguide devices mainly consist of a lower cladding layer, a light-guiding core layer, and an upper cladding layer. The core layer generally plays the role of transmitting light and communication, and its properties significantly affect the overall performance of the device.

[0003] Currently, the main photoresist materials used domestically and internationally for fabricating optical devices are SU8 phenolic epoxy resin series, generally used as the core layer of devices. While SU8 exhibits low overall absorption in the ultraviolet, visible, and near-infrared regions, it does absorb in communication wavelengths such as 850nm, 1310nm, and 1550nm. Therefore, when used in the fabrication of optical communication devices, such as thermo-optical modulators, encoders, and optical attenuators, it leads to excessively high optical loss (typically 1-2 dB / cm for simple structures). In some cases, the material's own absorption can even prevent the device from passing optical tests, severely limiting the development of optical waveguide technology. Furthermore, since the widely used SU8 is currently only a single material, there are no suitable cladding materials to pair with it. Researchers typically use polymethyl methacrylate (PMMA) as the upper and lower cladding layers for devices. However, due to the significant structural differences between alkyl-chain PMMA and aryl SU8 epoxy materials, the thermal expansion coefficients, glass transition temperatures, and surface energies of the cladding and core materials differ considerably. This results in poor matching between the cladding and core layers, making it easy for issues such as cladding thermal shrinkage causing waveguide pattern bending and poor bonding between the core and cladding to occur during device fabrication. Consequently, this can lead to poor device performance and even render the device unusable. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a fluorinated acrylate polymer and its preparation method, as well as a fluorinated polymer photoresist material and its application. When the fluorinated acrylate polymer provided by this invention is used in a fluorinated polymer photoresist material, it can simultaneously serve as the core layer and cladding layer of an optical waveguide device, resulting in good matching and strong bonding between the core and cladding layers, thereby improving the performance of the optical waveguide device.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a fluorinated acrylate polymer, obtained by free radical polymerization of monomers;

[0007] The monomers include fluorinated acrylate monomers and epoxy monomers;

[0008] The fluorinated acrylate monomer is a monomer with the structure shown in G1 and / or a monomer with the structure shown in G2.

[0009] G1 is

[0010] G2 is

[0011] In G1, x is an integer from 0 to 10, and n is an integer from 1 to 15;

[0012] In G2, y is an integer from 0 to 10, and m is an integer from 1 to 15;

[0013] The epoxy monomer is One or more of 3,4-epoxycyclohexyl methacrylate, 1,2-epoxy-4-vinylcyclohexane, 3,4-epoxycyclohexyl methyl methacrylate, and 3,4-epoxycyclohexyl acrylate.

[0014] Preferably, the monomer further includes an auxiliary monomer;

[0015] The auxiliary monomer is a monomer with the structure shown in G3 and / or a monomer with the structure shown in G4;

[0016] G3 is

[0017] G4 is and / or

[0018] In G3, z is an integer from 0 to 10.

[0019] Preferably, the fluorinated acrylate polymer has a number average molecular weight of 1,000 to 100,000, a dispersion of 1.0 to 4.6, and a viscosity range of 50 to 15,000 mPa·s.

[0020] This invention also provides a method for preparing the fluorinated acrylate polymer described in the above technical solution, comprising the following steps:

[0021] The monomer, free radical initiator, chain transfer agent and reaction solvent are mixed and subjected to free radical polymerization to obtain the fluorinated acrylate polymer.

[0022] Preferably, the free radical polymerization reaction is carried out at a temperature of 70–80°C for 6–10 hours.

[0023] This invention also provides a fluorinated polymer photoresist material, comprising the following raw materials in the indicated mass fractions:

[0024] 5-70% fluorinated acrylate polymer, 0.1-10% photoinitiator, 20-90% solvent;

[0025] The fluorinated acrylate polymer is the fluorinated acrylate polymer described in the above technical solution or the fluorinated acrylate polymer prepared by the preparation method described in the above technical solution.

[0026] Preferably, the photoinitiator is a thionium salt and / or an iodonium salt.

[0027] Preferably, the thioonium salt includes one or more of triphenylthioonium salt, triphenylhexafluorophosphate thioonium salt, triphenylhexafluoroarsenate thioonium salt, triphenyltetrafluoroborate thioonium salt, 4-methylphenyldiphenylhexafluorophosphate thioonium salt, and 4-(phenylthio)phenylhexafluorophosphate thioonium salt;

[0028] The iodonium salts include one or more of triphenyliodonium salt, diphenylhexafluoroantimony iodonium salt, diphenylhexafluorophosphate iodonium salt, diphenylhexafluoroarsenate iodonium salt, diphenyltetrafluoroborate iodonium salt, xylylhexafluoroarsenate iodonium salt, and di-tert-butylphenylhexafluorophosphate iodonium salt.

[0029] Preferably, the solvent comprises one or more of the following: propylene glycol monoalkyl ether, propylene glycol alkyl ether acetate, cyclopentanone, butyl acetate, methyl isobutyl ketone, 2-pentanone, 4-methyl-2-pentanone, cyclohexanone, 2-heptanone, γ-butyrolactone, ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, and butyrolactone.

[0030] The present invention also provides the application of the fluorinated polymer photoresist material described in the above technical solution in optical waveguide devices.

[0031] This invention provides a fluorinated acrylate polymer, obtained by free radical polymerization of monomers;

[0032] The monomers include fluorinated acrylate monomers and epoxy monomers; the fluorinated acrylate monomers are monomers with the structure shown in G1 and / or monomers with the structure shown in G2.

[0033] G1 is

[0034] G2 is

[0035] In G1, x is an integer from 0 to 10, and n is an integer from 1 to 15;

[0036] In G2, y is an integer from 0 to 10, and m is an integer from 1 to 15;

[0037] The epoxy monomer is One or more of 3,4-epoxycyclohexyl methacrylate, 1,2-epoxy-4-vinylcyclohexane, 3,4-epoxycyclohexyl methyl methacrylate, and 3,4-epoxycyclohexyl acrylate.

[0038] The fluorinated acrylate polymer of this invention introduces a fluorinated polyacrylate structure with an alkyl chain as the main structure. By replacing hydrogen atoms with fluorine atoms, the overtone absorption of CH bonds at optical communication wavelengths is reduced, thus reducing transmission optical loss (typically 0.3-0.4 dB / cm). Furthermore, by replacing hydrogen atoms with fluorine, when used in fluorinated polymer photoresist materials, the surface energy of the photoresist material is reduced, resulting in better film-forming properties compared to SU8 (SU8 photoresist requires a humidity of approximately 35-45% to achieve good film-forming properties, while this fluorinated polymer photoresist material can form films within a humidity range of 20%-55%). More importantly, this invention can prepare fluorinated acrylate polymers with different refractive indices simply by fine-tuning the raw material formulation of the fluorinated acrylate polymer (such as the type and ratio of monomers). This allows fluorinated polymer photoresist materials to be used simultaneously as the cladding and core layer of optical waveguide devices, improving the matching and bonding strength between the cladding and core layers, simplifying the fabrication of optical waveguide devices, and enabling the easy fabrication of optical waveguide devices with steep sidewalls, flat surfaces, and low optical loss. The fabricated straight single-mode devices have an optical loss of 0.32–0.4 dB / cm, and the straight multimode devices have an optical loss of 0.24–0.31 dB / cm. Attached Figure Description

[0039] Figure 1 The 1H NMR spectrum of the fluorinated acrylate polymer obtained in Example 1;

[0040] Figure 2 The glass transition temperature curve of the fluorinated acrylate polymer obtained in Example 2 is shown below.

[0041] Figure 3The 1H NMR spectrum of the fluorinated acrylate polymer obtained in Example 3;

[0042] Figure 4 The NMR fluorine spectrum of the fluorinated acrylate polymer obtained in Example 3;

[0043] Figure 5 This is an electron microscope image of the end face of the 5×5 micrometer waveguide device fabricated in Example 4;

[0044] Figure 6 The image shows the morphology of the 5×5 micrometer waveguide device prepared in Example 4. Detailed Implementation

[0045] This invention provides a fluorinated acrylate polymer, obtained by free radical polymerization of monomers;

[0046] The monomers include fluorinated acrylate monomers and epoxy monomers;

[0047] The fluorinated acrylate monomer is a monomer with the structure shown in G1 and / or a monomer with the structure shown in G2.

[0048] G1 is

[0049] G2 is

[0050] In G1, x is an integer from 0 to 10, and n is an integer from 1 to 15;

[0051] In G2, y is an integer from 0 to 10, and m is an integer from 1 to 15;

[0052] The epoxy monomer is One or more of 3,4-epoxycyclohexyl methacrylate, 1,2-epoxy-4-vinylcyclohexane, 3,4-epoxycyclohexyl methyl methacrylate, and 3,4-epoxycyclohexyl acrylate.

[0053] The raw materials for preparing the fluorinated acrylate polymer provided by this invention include monomers; the monomers include fluorinated acrylate monomers and epoxy monomers. In this invention, the fluorinated acrylate monomer is a monomer with the structure shown in G1 and / or a monomer with the structure shown in G2;

[0054] G1 is In G1, x is an integer from 0 to 10, preferably 1 to 8, and more preferably 2 to 6; n is an integer from 1 to 15, preferably 3 to 12, more preferably 5 to 10, and more preferably 6 to 8. In a specific embodiment of this invention, G1 is preferably tridecafluorooctyl acrylate, having the structure shown in Formula A:

[0055]

[0056] G2 is In G2, y is an integer from 0 to 10, preferably 1 to 9, more preferably 2 to 5; m is an integer from 1 to 15, preferably 3 to 12, further preferably 5 to 10, and more preferably 6 to 8. In a specific embodiment of the present invention, G2 is preferably 2-(perfluorohexyl)ethyl methacrylate, having the structure shown in Formula B:

[0057]

[0058] In this invention, the epoxy monomer is One or more of 3,4-epoxycyclohexyl methacrylate, 1,2-epoxy-4-vinylcyclohexane, 3,4-epoxycyclohexyl methyl methacrylate, and 3,4-epoxycyclohexyl acrylate, preferably. The Its name is glycidyl methacrylate.

[0059] In this invention, the monomer preferably further includes an auxiliary monomer. In this invention, the auxiliary monomer preferably includes a monomer with the structure shown in G3 and / or a monomer with the structure shown in G4;

[0060] G3 is In G3, z is an integer from 0 to 10, preferably from 1 to 8, and more preferably from 2 to 6. In a specific embodiment of the present invention, z in G3 is preferably 2, and the name is hydroxyethyl methacrylate.

[0061] G4 is and / or

[0062] In this invention, the number average molecular weight of the fluorinated acrylate polymer is preferably 1,000 to 100,000, more preferably 5,000 to 32,000; the dispersity is preferably 1.0 to 4.6, more preferably 1.4 to 2; and the viscosity range is preferably 50 to 15,000 mPa·s.

[0063] This invention does not impose specific limitations on the amount ratio of monomers with structures shown in G1 and G2 in the fluorinated acrylate monomer, the amount ratio of the fluorinated acrylate monomer to the auxiliary monomer, the amount ratio of the fluorinated acrylate monomer to the epoxy monomer, and the amount ratio of monomers with structures shown in G3 and G4 in the auxiliary monomer. Those skilled in the art can adjust these ratios based on the refractive index and number-average molecular weight of the fluorinated acrylate polymer.

[0064] In this invention, the conditions for the free radical polymerization are preferably described in detail in the preparation method section of the fluorinated acrylate polymer, and will not be described here again.

[0065] This invention also provides a method for preparing the fluorinated acrylate polymer described in the above technical solution, comprising the following steps:

[0066] The monomer, free radical initiator, chain transfer agent and reaction solvent are mixed and subjected to free radical polymerization to obtain the fluorinated acrylate polymer.

[0067] Unless otherwise specified, all raw materials used in this invention are preferably commercially available products.

[0068] In this invention, the free radical initiator is preferably azobisisobutyronitrile and / or azobisisovalerate. In this invention, the mass ratio of the free radical initiator to the monomer is preferably (1.2–2):(170–300).

[0069] In this invention, the chain transfer agent is preferably n-dodecyl mercaptan and / or carbon tetrachloride. In this invention, the mass ratio of the chain transfer agent to the monomer is preferably 2:(170-300).

[0070] In this invention, the reaction solvent is preferably cyclohexanone and / or cyclopentanone. In this invention, the mass ratio of the reaction solvent to the monomer is preferably (100–200):(170–300).

[0071] In this invention, the mixing of the monomer, free radical initiator, chain transfer agent and reaction solvent is preferably carried out under stirring conditions.

[0072] In this invention, the temperature of the free radical polymerization reaction is preferably 70-80°C, more preferably 75°C; the time is preferably 6-10 hours, more preferably 8 hours.

[0073] Following the free radical polymerization reaction, the present invention preferably further includes a post-treatment process; the post-treatment preferably includes the following steps: adding the product obtained from the free radical polymerization reaction dropwise into petroleum ether, allowing it to precipitate to obtain a solid; and drying the solid. The present invention does not specifically limit the drying parameters, as long as the solvent is completely removed.

[0074] This invention also provides a fluorinated polymer photoresist material, comprising the following raw materials in the indicated mass fractions:

[0075] 5-70% fluorinated acrylate polymer, 0.1-10% photoinitiator, 20-90% solvent;

[0076] The fluorinated acrylate polymer is the fluorinated acrylate polymer described in the above technical solution or the fluorinated acrylate polymer prepared by the preparation method described in the above technical solution.

[0077] The raw materials for preparing the fluorinated polymer photoresist material provided by this invention include 5-70% by mass of a fluorinated acrylate polymer, preferably 50-70%, and more preferably 50-60%. In this invention, the fluorinated acrylate polymer is the fluorinated acrylate polymer described in the above-described technical solution or the fluorinated acrylate polymer prepared by the preparation method described in the above-described technical solution.

[0078] The raw materials for preparing the fluorinated polymer photoresist material provided by this invention include a photoinitiator with a mass fraction of 0.1-10%, preferably 1-5%, and more preferably 2-3%. In this invention, the photoinitiator is preferably a thionium salt and / or an iodonium salt. In this invention, the thionium salt preferably includes one or more of triphenylthionium salt, triphenylhexafluorophosphate thionium salt, triphenylhexafluoroarsenate thionium salt, triphenyltetrafluoroborate thionium salt, 4-methylphenyldiphenylhexafluorophosphate thionium salt, and 4-(phenylthio)phenylhexafluorophosphate thionium salt. In this invention, the iodonium salt preferably includes one or more of triphenyliodonium salt, diphenylhexafluoroantimony iodonium salt, diphenylhexafluorophosphate iodonium salt, diphenylhexafluoroarsenate iodonium salt, diphenyltetrafluoroborate iodonium salt, xylylhexafluoroarsenate iodonium salt, and di-tert-butylphenylhexafluorophosphate iodonium salt.

[0079] The raw materials for preparing the fluorinated polymer photoresist material provided by this invention include a solvent with a mass fraction of 20-90%, preferably 30-70%, and more preferably 40-50%. In this invention, the solvent preferably includes one or more of the following: propylene glycol monoalkyl ether, propylene glycol alkyl ether acetate, cyclopentanone, butyl acetate, methyl isobutyl ketone, 2-pentanone, 4-methyl-2-pentanone, cyclohexanone, 2-heptanone, γ-butyrolactone, ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, and butyrolactone, and more preferably cyclopentanone.

[0080] The present invention also provides the application of the fluorinated polymer photoresist material described in the above technical solution in optical waveguide devices.

[0081] In this invention, when the fluorinated polymer photoresist material is used in optical waveguide devices, it is preferably used as a core layer or cladding layer. In this invention, when the fluorinated polymer photoresist material is used as a core layer or cladding layer, it is preferably prepared according to the requirements of the optical waveguide device for the core layer and cladding layer.

[0082] In this invention, the fabrication method of the optical waveguide device preferably includes the following steps:

[0083] A fluorinated polymer photoresist material, serving as the lower cladding layer, is spin-coated onto a substrate, and then sequentially subjected to a first pre-baking, a first ultraviolet full exposure, and a first post-baking curing to obtain the lower cladding layer.

[0084] A fluorinated polymer photoresist material, serving as the core layer, is spin-coated onto the lower cladding layer. Then, a second pre-baking, mask ultraviolet exposure, a second post-baking curing, development, and hardening are performed sequentially to obtain the core layer.

[0085] The fluorinated polymer photoresist material, which serves as the upper cladding layer, is spin-coated onto the core layer, and then subjected to a third pre-bake, a second ultraviolet full exposure, and a third post-bake in sequence to obtain the optical waveguide device.

[0086] In this invention, a fluorinated polymer photoresist material, which serves as the lower cladding layer, is spin-coated onto a substrate, and then sequentially subjected to a first pre-baking, a first ultraviolet full exposure, and a first post-baking curing to obtain the lower cladding layer.

[0087] In this invention, the substrate is preferably SiO2 or a PCB epoxy resin electronic board. In this invention, the spin coating speed is preferably 1500–3000 rpm. In this invention, the thickness of the fluorinated polymer photoresist material spin-coated onto the substrate as the lower cladding layer is preferably 1 nm–200 μm. In this invention, the temperature of the first pre-baking is preferably 50–130°C, and the time is preferably 10–40 min. In this invention, the time of the first ultraviolet full exposure is preferably 0.2–360 s, the exposure wavelength is preferably 200–500 nm, and the exposure power is preferably 10–200 mW / cm². 2 In this invention, the temperature for the first post-curing process is preferably 50–160°C, and the time is preferably 10–20 min.

[0088] After obtaining the lower cladding layer, the present invention spin-coates the fluorinated polymer photoresist material, which serves as the core layer, onto the lower cladding layer, and sequentially performs a second pre-baking, mask ultraviolet exposure, a second post-baking, development, and hardening to obtain the core layer.

[0089] In this invention, the temperature of the second pre-baking is preferably 50–130°C, and the time is preferably 10–40 min. In this invention, the UV exposure time of the mask is preferably 2–360 s, the exposure wavelength is preferably 200–500 nm, and the exposure power is preferably 10–100 mW / cm². 2In this invention, the second post-curing temperature is preferably 50–160°C, and the time is preferably 10–20 min. In this invention, the developing solution preferably includes one or more of propylene glycol monoalkyl ether, propylene glycol alkyl ether acetate, cyclopentanone, butyl acetate, methyl isobutyl ketone, 2-pentanone, 4-methyl-2-pentanone, cyclohexanone, 2-heptanone, γ-butyrolactone, ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether acetate, butyrolactone, and cyclopentanone, more preferably cyclopentanone. In this invention, the developing time is preferably 20–180 s. In this invention, the hardening temperature is preferably 90–160°C, more preferably 120–150°C; the time is preferably 20–120 min, more preferably 30–90 min.

[0090] After obtaining the core layer, the present invention spin-coates a fluorinated polymer photoresist material as the upper cladding layer onto the core layer, and sequentially performs a third pre-baking, a second ultraviolet full exposure, and a third post-baking to obtain the optical waveguide device.

[0091] In this invention, the spin coating speed is preferably 1500-2000 rpm. In this invention, the fluorinated polymer photoresist material, serving as the upper cladding layer, is spin-coated onto the core layer, and the other parameters for the third pre-baking, second UV full exposure, and third post-baking are preferably consistent with the parameters for preparing the lower cladding layer described above, and will not be repeated here.

[0092] The following detailed description of the fluorinated acrylate polymer and its preparation method provided by the present invention, with reference to the embodiments, should not be construed as limiting the scope of protection of the present invention.

[0093] Example 1

[0094] Preparation of fluorinated acrylate polymers as cladding materials:

[0095] 40g of 2-(perfluorohexyl)ethyl methacrylate (CAS No. 2144-53-8), 80g of tridecafluorooctyl acrylate (CAS No. 17527-29-6), 40g of glycidyl methacrylate and 10g of hydroxyethyl methacrylate (CAS No. 868-77-9) were used as monomers, 1.2g of azobisisobutyronitrile was used as a free radical initiator, 100g of cyclohexanone was used as a reaction solvent, and 2g of n-dodecyl mercaptan was used as a chain transfer agent. The mixture was added to a stirrable container, the temperature was set at 75℃, and the reaction was stopped after 6 hours. The reaction solution was then added dropwise to petroleum ether to precipitate a white solid. After drying the solvent, the fluorinated acrylate polymer was obtained.

[0096] The refractive index of the cured fluorinated acrylate polymer was 1.42. GPC (gel permeation chromatography) showed a number-average molecular weight of 8000 and a dispersity of 1.9.

[0097] The 1H NMR spectrum of the obtained fluorinated acrylate polymer is shown below. Figure 1 As shown, from Figure 1 It can be seen that each raw material peak in the polymer corresponds one-to-one.

[0098] Example 2

[0099] Preparation of fluorinated acrylate polymers as core layer materials:

[0100] 50g of 2-(perfluorohexyl)ethyl methacrylate (CAS No. 2144-53-8), 120g of tridecafluorooctyl acrylate (CAS No. 17527-29-6), 30g of glycidyl methacrylate, 10g of hydroxyethyl methacrylate (CAS No. 868-77-9), 20g of pentafluorostyrene, 1.5g of azobisisobutyronitrile, 130g of cyclohexanone, and 2g of n-dodecyl mercaptan were added to a stirrable container. The temperature was set to 75℃, and the reaction was stopped after 8 hours. The reaction solution was then added dropwise to petroleum ether, from which a white solid precipitated. After drying the solvent, the fluorinated acrylate polymer was obtained.

[0101] The refractive index of the cured fluorinated acrylate polymer was 1.44. GPC (gel permeation chromatography) showed a number-average molecular weight of 12,000 and a dispersity of 1.7.

[0102] Figure 2 The glass transition temperature profile of the obtained fluorinated acrylate polymer is obtained from... Figure 2 It can be seen that the glass transition temperature of the polymer is 116℃.

[0103] Example 3

[0104] Preparation of fluorinated acrylate polymers as core layer materials:

[0105] 60g of 2-(perfluorohexyl)ethyl methacrylate (CAS No. 2144-53-8), 110g of tridecafluorooctyl acrylate (CAS No. 17527-29-6), 50g of glycidyl methacrylate, 15g of hydroxyethyl methacrylate (CAS No. 868-77-9), 20g of styrene, 2g of azobisisobutyronitrile, 160g of cyclohexanone, and 2g of n-dodecyl mercaptan were added to a stirrable container. The temperature was set to 75℃, and the reaction was stopped after 8 hours. The reaction solution was then added dropwise to petroleum ether, from which a white solid precipitated. After drying the solvent, the fluorinated acrylate polymer was obtained.

[0106] The refractive index of the cured fluorinated acrylate polymer was 1.45. GPC (gel permeation chromatography) showed a number-average molecular weight of 15,000 and a dispersity of 2.1.

[0107] The 1H NMR spectrum of the obtained fluorinated acrylate polymer is shown below. Figure 3 As shown, the NMR fluorine spectrum of the obtained fluorinated acrylate polymer is as follows. Figure 4 As shown, from Figure 3 and Figure 4 It can be seen that the hydrogen and fluorine spectrum peaks of the polymer in the core layer material correspond one-to-one with the peaks of the raw material.

[0108] Example 4

[0109] A single-mode optical waveguide device was fabricated using the fluorinated acrylate polymer prepared in Example 1 as the cladding material and the fluorinated acrylate polymer prepared in Example 2 as the core material.

[0110] 10g of the fluorinated acrylate polymer obtained in Example 1 was dissolved in cyclopentanone with a solid content of 10%, and 0.3g of diphenylthionium salt was added. After dissolution and filtration, a colorless and transparent lower cladding photoresist solution was obtained.

[0111] The lower cladding photoresist solution was spin-coated onto a clean silicon wafer at 2000 rpm for 40 s. Pre-baking was performed at 60°C and 90°C for 10 min each. After heating, full UV exposure was performed for 10 s, followed by post-baking at 60°C and 90°C for 10 min each for curing. The resulting lower cladding film was insoluble in cyclopentanone, and its thickness was measured to be 1 μm.

[0112] 10g of the fluorinated acrylate polymer obtained in Example 2 was dissolved in cyclopentanone with a solid content of 10%, and 0.2g of diphenylthionium salt was added. After dissolution and filtration, a colorless and transparent core layer photoresist solution was obtained.

[0113] The core layer photoresist solution was spin-coated onto the lower cladding film at 2000 rpm for 40 s. Pre-baking was performed at 60°C and 90°C for 10 min each. After heating, mask exposure was performed for 5 s, followed by post-baking at 60°C and 90°C for 10 min each. The cured film was developed using cyclopentanone as the developer. The unexposed portions dissolved in cyclopentanone, thus forming a waveguide pattern. The film was then hardened at 120°C for 30 min to obtain the core layer. The thickness of the core layer was measured to be 1 μm.

[0114] The upper cladding layer is prepared on the core layer according to the preparation method of the lower cladding layer. The parameters of pre-baking, UV full exposure and post-baking curing remain unchanged. Only the spin coating speed needs to be reduced to 1500 rpm to obtain a straight optical waveguide device.

[0115] The optical loss of the obtained straight optical waveguide device is 0.27 dB / cm.

[0116] The optical waveguide pattern on the end face of the obtained straight optical waveguide device is as follows Figure 5 As shown, from Figure 5 It can be seen that the fabricated single-mode waveguide device has a good morphology.

[0117] Example 5

[0118] A multimode optical waveguide device was fabricated using the fluorinated acrylate polymer prepared in Example 1 as the cladding material and the fluorinated acrylate polymer prepared in Example 3 as the core material.

[0119] 20g of the fluorinated acrylate polymer obtained in Example 1 was dissolved in cyclopentanone with a solid content of 70%, and 0.6g of diphenylthionium salt was added. After dissolution and filtration, a colorless and transparent lower cladding photoresist solution was obtained.

[0120] The lower cladding photoresist solution was spin-coated onto a clean silicon wafer at 1600 rpm for 40 seconds. Pre-baking was performed at 60°C and 90°C for 20 minutes each, followed by UV full exposure for 30 seconds. Post-baking was then performed at 60°C and 90°C for 15 minutes each to cure the lower cladding film. The lower cladding film was insoluble in the solvent cyclopentanone, and the thickness of the cured lower cladding film was measured to be 50 μm.

[0121] 20g of the fluorinated acrylate polymer obtained in Example 3 was dissolved in cyclopentanone with a solid content of 70%, and 0.4g of diphenylthionium salt was added. After dissolution and filtration, a colorless and transparent core layer photoresist solution was obtained.

[0122] The core layer photoresist solution was spin-coated onto the lower cladding film at 1600 rpm for 40 s. Pre-baking was performed at 60°C and 90°C for 15 min each. After heating, mask exposure was performed for 20 s, followed by post-baking at 60°C and 90°C for 20 min each. The cured film was developed using cyclopentanone as the developer. The unexposed portions dissolved in cyclopentanone, thus forming a waveguide pattern. The film was then hardened at 120°C for 30 min to obtain the core layer. The core layer thickness was measured to be 50 μm.

[0123] The upper cladding layer is prepared on the core layer according to the preparation method of the lower cladding layer. The parameters of pre-baking, UV full exposure and post-baking curing remain unchanged. Only the spin coating speed needs to be reduced to 1500 rpm to obtain a straight optical waveguide device.

[0124] The optical loss of the obtained straight optical waveguide device is 0.36 dB / cm.

[0125] The optical waveguide pattern on the end face of the obtained straight optical waveguide device is as follows Figure 6 As shown, from Figure 6 It can be seen that the fabricated multimode waveguide device has a good morphology.

[0126] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An application of a fluorinated polymer photoresist material in optical waveguide devices, characterized in that, The fluorinated polymer photoresist material comprises the following raw materials by mass fraction: 5-70% fluorinated acrylate polymer, 0.1-10% photoinitiator, 20-90% solvent; The fluorinated acrylate polymer is obtained by free radical polymerization of monomers; The monomers include fluorinated acrylate monomers and epoxy monomers; The fluorinated acrylate monomer is a monomer with the structure shown in G1 and a monomer with the structure shown in G2; G1 is ; G2 is ; In G1, x is an integer from 1 to 8, and n is an integer from 5 to 10; In G2, y is an integer from 1 to 9, and m is an integer from 5 to 10; The epoxy monomer is One or more of the following: 3,4-epoxycyclohexyl methacrylate, 1,2-epoxy-4-vinylcyclohexane, 3,4-epoxycyclohexyl methacrylate, and 3,4-epoxycyclohexyl acrylate; The monomer further includes an auxiliary monomer; the auxiliary monomer is a monomer with the structure shown in G3 and / or a monomer with the structure shown in G4; G3 is ; G4 is ; In G3, z is an integer from 2 to 6.

2. The application according to claim 1, characterized in that, The fluorinated acrylate polymer has a number average molecular weight of 1,000 to 100,000, a dispersion of 1.0 to 4.6, and a viscosity range of 50 to 15,000 mPa·s.

3. The application according to claim 1, characterized in that, The preparation method of the fluorinated acrylate polymer includes the following steps: The monomer, free radical initiator, chain transfer agent and reaction solvent are mixed and subjected to free radical polymerization to obtain the fluorinated acrylate polymer.

4. The application according to claim 3, characterized in that, The free radical polymerization reaction is carried out at a temperature of 70-80°C for 6-10 hours.

5. The application according to claim 1, characterized in that, The photoinitiator is a thionium salt and / or an iodonium salt.

6. The application according to claim 5, characterized in that, The thioonium salt includes one or more of triphenylthioonium salt, triphenylhexafluorophosphate thioonium salt, triphenylhexafluoroarsenate thioonium salt, triphenyltetrafluoroborate thioonium salt, 4-methylphenyldiphenylhexafluorophosphate thioonium salt, and 4-(phenylthio)phenylhexafluorophosphate thioonium salt; The iodonium salts include one or more of triphenyliodonium salt, diphenylhexafluoroantimony iodonium salt, diphenylhexafluorophosphate iodonium salt, diphenylhexafluoroarsenate iodonium salt, diphenyltetrafluoroborate iodonium salt, xylylhexafluoroarsenate iodonium salt, and di-tert-butylphenylhexafluorophosphate iodonium salt.

7. The application according to claim 1, characterized in that, The solvent includes one or more of the following: propylene glycol monoalkyl ether, propylene glycol alkyl ether acetate, cyclopentanone, butyl acetate, methyl isobutyl ketone, 2-pentanone, 4-methyl-2-pentanone, cyclohexanone, 2-heptanone, γ-butyrolactone, ethylene glycol monoethyl ether acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, and butyrolactone.

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