5G substrate-oriented low-dielectric spherical ceramic powder polyphenyl ether composite dielectric material

Abstract

The invention discloses a low-dielectric spherical ceramic powder and polyphenyl ether composite dielectric material for a 5G substrate, and belongs to the technical field of organic polymer materials. The composite material is prepared from the following components in parts by weight: 25 to 60 parts of modified polyphenyl ether, 30 to 60 parts of spherical ceramic powder modified by a sulfydryl silane coupling agent, 0.01 to 5 parts of a compatibilizer, 0.5 to 3 parts of an antioxidant, 0.5 to 2 parts of a release agent and 0.1 to 0.6 part of an initiator, the modified polyphenyl ether is prepared from side chain brominated methyl-terminated polyphenyl ether grafted with a trifluoromethylated acrylate hydroxyl compound. The low-dielectric spherical ceramic powder polyphenyl ether composite dielectric material can effectively reduce the dielectric constant and dielectric loss, and has good interfacial compatibility and mechanical properties.

Description

[0001] The application belongs to the technical field of organic polymer materials, and particularly relates to a low-dielectric spherical ceramic powder polyphenyl ether composite dielectric material for a 5G substrate. BACKGROUND

[0002] With the evolution of 5G communication technology towards high frequency and high speed, the substrate as a core carrier for carrying electronic components and signal transmission puts forward strict requirements on the dielectric properties of dielectric materials, that is, low dielectric constant and low dielectric loss are required to reduce signal delay and transmission loss, and excellent mechanical properties are also required. However, the existing dielectric materials face multiple challenges: although the traditional polyphenyl ether has excellent dielectric properties, the mechanical strength of the pure matrix is insufficient, and inorganic fillers need to be introduced for reinforcement, which is easy to cause the interface polarization to be intensified due to poor interface compatibility between the fillers and the matrix, thereby increasing the dielectric loss; the surface polarity of the spherical ceramic powder as a commonly used reinforcing filler is difficult to match the non-polar structure of the polyphenyl ether, and agglomeration is easy to occur, resulting in imbalance between the mechanical properties and the dielectric properties of the material; in addition, the stability of the dielectric properties of the material under a high-frequency environment and the uniformity of the processing technology are also difficult to be considered. SUMMARY

[0003] In order to overcome the deficiencies of the prior art, the application provides a low-dielectric spherical ceramic powder polyphenyl ether composite dielectric material for a 5G substrate, which can effectively reduce the dielectric constant and the dielectric loss, and at the same time, good interface compatibility and mechanical properties are considered. The technical scheme for realizing the purpose of the application is as follows:

[0004] A low-dielectric spherical ceramic powder polyphenyl ether composite dielectric material for a 5G substrate, by weight, comprises: 25-60 parts of modified polyphenyl ether, 30-60 parts of spherical ceramic powder modified by a mercapto silane coupling agent, 0.01-5 parts of a compatibilizer, 0.5-3 parts of an antioxidant, 0.5-2 parts of a release agent, and 0.1-0.6 parts of an initiator; the structure of the modified polyphenyl ether is shown in formula 1:

[0005] In formula 1, the ratio of x to y is (2-5):(5-8).

[0006] The preparation method of the spherical ceramic powder modified by the mercapto silane coupling agent comprises the following steps:

[0007] 0.5-3 parts of water and 8-30 parts of ethanol are mixed, 0.1-1 mol / L dilute hydrochloric acid is added dropwise to adjust the pH to 4-6, 0.5-3 parts of a mercapto silane coupling agent is added, the temperature is adjusted to 20-50 DEG C, and stirring is performed for 0.5-3 h; 30-60 parts of spherical ceramic powder is added into the above solution, stirring is performed for 0.5-2 h, and ultrasonic dispersion is performed for 0.5-5 h, and then the solvent is removed to obtain the spherical ceramic powder modified by the mercapto silane coupling agent.

[0008] The mercaptosilane coupling agent is one or more of 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 11-mercaptoundecyltrimethoxysilane.

[0009] The spherical ceramic powder includes one or more of spherical silicon dioxide, spherical aluminum oxide, spherical aluminum nitride, and spherical magnesium oxide; preferably, the spherical ceramic powder is hollow spherical silicon dioxide.

[0010] The compatibilizer is an olefin copolymer containing epoxy groups; preferably, the compatibilizer is ethylene-glycidyl methacrylate.

[0011] The antioxidant includes one or more of antioxidant 1076, antioxidant 1010, and antioxidant 168.

[0012] The release agent includes one or both of pentaerythritol tetrastearate and linear low-density polyethylene.

[0013] The initiator is selected from tert-butyl peroxide.

[0014] The preparation method of the modified polyphenylene ether comprises the following steps:

[0015] 1 eq of side chain brominated methyl polyphenylene ether is dissolved in chlorobenzene and stirred; a trifluoromethylated acrylate hydroxy compound equivalent to 0.2 to 0.5 times the molar amount of the side chain brominated methyl polyphenylene ether, potassium carbonate equivalent to 0.9 to 1.1 times the molar amount of the side chain brominated methyl polyphenylene ether, and dimethyl sulfoxide are added in sequence, and the mixture is stirred at 75 to 85° C. for 18 to 22 hours; after the reaction is completed, the mixture is cooled to room temperature and filtered, the filtrate is washed with deionized water, dried over anhydrous sodium sulfate, and then concentrated under reduced pressure, the concentrate is poured into methanol to precipitate, and the precipitate is purified by silica gel column chromatography to obtain the modified polyphenylene ether.

[0016] The preparation method of the side chain brominated methyl-terminated polyphenylene ether comprises the following steps:

[0017] (1) Synthesis of methyl-terminated polyphenylene ether: Under a nitrogen atmosphere, 1 eq of polyphenylene ether was dissolved in anhydrous tetrahydrofuran, and iodomethane and potassium carbonate were added in an amount equivalent to 2.1 to 2.2 times and 2.4 to 2.5 times the molar amount of polyphenylene ether, respectively, and stirred at room temperature. After the reaction was completed, the solid residue was removed by filtration, the filtrate was concentrated under reduced pressure, poured into methanol to precipitate, and the precipitate was collected by vacuum filtration and washed three times with cold methanol, and dried in vacuum to obtain a solid product, methyl-terminated polyphenylene ether.

[0018] (2) Synthesis of side chain brominated end-methyl polyphenylene ether: Under an argon atmosphere, 1 eq of end-methyl polyphenylene ether was dissolved in carbon tetrachloride, and azobisisobutyronitrile and N-bromosuccinimide were added while stirring, with the amount corresponding to 0.03 to 0.04 times and 0.2 to 0.5 times the molar amount of end-methyl polyphenylene ether, respectively. The mixture was reacted at 55 to 65°C for 7 to 9 hours, then cooled to room temperature, and diluted with deionized water while stirring at 300 to 500 rpm; the organic phase was separated, and methanol was poured into the precipitate, which was collected by vacuum filtration and dried to obtain a solid product, side chain brominated end-methyl polyphenylene ether.

[0019] Specifically, the molecular weight of the terminal methyl polyphenylene ether is 16,000 to 24,000; and the molecular weight of the side chain brominated terminal methyl polyphenylene ether is 38,000 to 48,000.

[0020] The preparation method of the trifluoromethylated acrylate hydroxy compound comprises the following steps:

[0021] (1) Under a nitrogen atmosphere, 1 eq of tetrabromobisphenol A that has been vacuum-dried is dissolved in anhydrous dichloromethane, and triethylamine, 4-dimethylaminopyridine, and a polymerization inhibitor are added in amounts of 1.1 to 1.3 times, 0.01 to 0.02 times, and 0.01 to 0.02 times the molar amount of tetrabromobisphenol A, respectively. After stirring evenly, acryloyl chloride equivalent to 2.1 to 2.3 times the molar amount of tetrabromobisphenol A is slowly added dropwise in an ice bath at 0 to 5°C, and the mixture is stirred at low temperature for 25 to 35 minutes. The mixture is then heated to room temperature and reacted for 3 to 5 hours. After the reaction is completed, the system is poured into ice water for quenching. The organic phase is collected and washed with 10% by mass dilute hydrochloric acid, saturated sodium bicarbonate solution, and deionized water in sequence until neutral. The organic phase is dried over anhydrous sodium sulfate, and the solvent is removed under reduced pressure. The product is purified by silica gel column chromatography and vacuum dried to obtain an acrylated product.

[0022] (2) In a dry flask, 1 eq of the acrylic esterification product, bis(pinacolato)diboron (4.5 to 4.6 times the molar amount of the acrylic esterification product), potassium carbonate, and 1,4-dioxane were mixed and degassed under nitrogen atmosphere. A palladium catalyst and a polymerization inhibitor were added under light-shielding conditions, wherein the amounts of potassium carbonate, palladium catalyst, and polymerization inhibitor were 3.0 to 3.5 times, 0.10 to 0.15 times, and 0.01 to 0.02 times the molar amount of the acrylic esterification product, respectively. The mixture was reacted at 80 to 90° C. for 20 to 24 hours. After the reaction, the mixture was extracted with ethyl acetate, the organic phases were combined, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography to obtain a borate compound.

[0023] (3) Under nitrogen atmosphere, the borate compound and para-bromotrifluorotoluene are dissolved in toluene at a molar ratio of (1.1-1.2):3, and after degassing for 10-20 minutes, a potassium carbonate aqueous solution is added, and degassing is repeated for 10-20 minutes; then, a palladium catalyst equivalent to 0.10-0.15 times the molar amount of the borate compound is added under light-proof conditions, and bubbling is performed to deoxygenate for 10-20 minutes. The mixture is reacted at 80-90°C for 20-24 hours; after the reaction, the mixture is extracted and separated with chloroform and water, and the organic phase is washed with saturated brine, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography to obtain a trifluoromethylated pinacol ester product;

[0024] (4) Under nitrogen atmosphere, the trifluoromethylated pinacol ester product and 4-bromophenol are dissolved in toluene at a molar ratio of (1.1-1.3):1, and after nitrogen bubbling for deoxygenation for 10-20 minutes, a potassium carbonate aqueous solution is added, and degassing is performed again for 10-20 minutes; under light-shielding conditions, a palladium catalyst equivalent to 0.10-0.15 times the molar amount of the trifluoromethylated pinacol ester product is added, and bubbling for deoxygenation for 10-20 minutes, and the mixture is reacted at 80-110° C. for 20-24 hours; after the reaction is completed, the mixture is extracted and separated with chloroform and water, and the organic phase is washed with saturated brine, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography to obtain a trifluoromethylated acrylate hydroxy compound.

[0025] Specifically, the palladium catalyst is one or both of tetrakis(triphenylphosphine)palladium and 1,1'-bis(di-tert-butylphosphino)ferrocenedichloropalladium; and the potassium carbonate aqueous solution is prepared by dissolving 1.25eq potassium carbonate in 0.5mL ultrapure water.

[0026] A method for preparing a low-dielectric spherical ceramic powder polyphenylene ether composite dielectric material for a 5G substrate comprises the following steps:

[0027] S1. Mixing: 25 to 60 parts of modified polyphenylene ether, 30 to 60 parts of spherical ceramic powder modified with a mercaptosilane coupling agent, 0.01 to 5 parts of a compatibilizer, 0.5 to 3 parts of an antioxidant, 0.5 to 2 parts of a release agent, and 0.1 to 0.6 parts of an initiator are added to a high-speed mixer and premixed at a speed of 800 to 1200 rpm for 10 to 15 minutes;

[0028] S2. Extrusion granulation: The temperature of each section of the twin-screw extruder is preheated to an appropriate range, the feed section temperature is set at 180-200 ° C, the compression section temperature is 200-220 ° C, the metering section temperature is 220-235 ° C, and nitrogen is introduced into the extrusion hopper at a flow rate of 5-10 L / min; the mixed material is added to the extruder hopper, and the material is pushed by the screw and sequentially undergoes conveying, compression, melting, mixing and other processes. The screw speed is controlled at 100-200 rpm so that the material is fully melted and mixed in the extruder and extruded from the die in a uniform strip shape; the extruded strip material is cooled by air to below 60 ° C and cut into low dielectric spherical ceramic powder polyphenylene ether composite particles with a particle size of 1-2 mm by a pelletizer;

[0029] S3. Hot pressing: Select a stainless steel mold, clean and preheat it at a temperature of 180-190°C; place the low-dielectric spherical ceramic powder polyphenylene ether composite particles into the preheated mold, and try to make the particles evenly distributed; place the mold containing the material into a hot press, and first maintain it at 5-10 MPa and 180-190°C for 2-3 minutes to allow the material to be initially compacted; then gradually increase the pressure to 10-20 MPa, and at the same time increase the temperature to 190-200°C, and maintain it for 5-8 minutes to allow the composite particles to fully melt and fill the mold cavity to form a composite dielectric material of the desired shape; after the hot pressing is completed, while maintaining the pressure, air-cool the mold to allow the material to cool down to 80°C at a rate of 1-2°C / min, and then air-cool to 50-60°C, and take out the molded low-dielectric spherical ceramic powder polyphenylene ether composite dielectric material.

[0030] Beneficial effects

[0031] The present invention designs a modified polyphenylene ether and applies it to a low-dielectric spherical ceramic powder polyphenylene ether composite dielectric material for 5G substrates, which has the following beneficial effects:

[0032] 1. Reduce dielectric constant and dielectric loss: 5G communication technology requires materials with low dielectric constant and low dielectric loss to reduce delays and energy loss during signal transmission. The trifluoromethyl group introduced into the modified polyphenylene ether has strong electronegativity and low polarizability, which can reduce the polarization degree of the molecule and effectively reduce the overall dielectric constant of the material. At the same time, the trifluoromethylated acrylate hydroxyl compound grafted into the modified polyphenylene ether contains symmetrical benzene rings, which helps to reduce uneven dipole distribution, suppress local electric field distortion, and reduce dielectric loss.

[0033] 2. Stable dielectric properties: The spherical ceramic powder and modified polyphenylene ether form a stable chemical bond through a mercaptosilane coupling agent, which makes the ceramic powder evenly dispersed in the polyphenylene ether matrix, reducing factors such as interfacial polarization that lead to unstable dielectric properties, ensuring that the material has stable dielectric properties at different frequencies and temperatures, meeting the requirements of 5G high-frequency and high-speed signal transmission;

[0034] Three, improve the mechanical properties: modified polyphenyl ether contains biphenyl groups, has a certain rigidity and strength, the addition of ceramic powder plays a role in enhancing the skeleton, can bear part of the external force, improve the tensile strength, bending strength and other mechanical properties of the composite material; at the same time, the side chain alkenyl is bonded with the ceramic powder through the chemical bonding of silane coupling agent and the interaction between the molecular chains of modified polyphenyl ether, which gives the material certain toughness, so that the material is not easy to brittle fracture when subjected to external force impact, and enhances the reliability and durability of 5G substrate;

[0035] Four, improve the thermal stability: the aromatic ring and stable chemical bond in the structure of modified polyphenyl ether, and the high temperature resistance of ceramic powder, make the composite material have high thermal decomposition temperature and glass transition temperature, can maintain stable physical and chemical properties at high temperature environment, meet the heat dissipation demand of 5G equipment in long time running process, avoid the performance degradation and substrate failure caused by high temperature. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 Synthetic route of trifluoromethylated acrylate hydroxyl compound 1;

[0037] Figure 2 Nuclear magnetic resonance hydrogen spectrum of trifluoromethylated acrylate hydroxyl compound 1;

[0038] Figure 3 Nuclear magnetic resonance hydrogen spectrum of modified polyphenyl ether 1. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0040] In the embodiments, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are commercially available unless otherwise specified.

[0041] The raw materials and equipment used in the examples and comparative examples are described as follows:

[0042] Side chain brominated end methyl polyphenyl ether: self-made, the preparation method is as follows:

[0043] (1) Synthesis of end-methyl polyphenylene ether: 1 eq of polyphenylene ether was dissolved in anhydrous tetrahydrofuran under nitrogen atmosphere, and iodomethane and potassium carbonate were added in sequence, the amount of which was 2.1 times and 2.4 times of the molar amount of polyphenylene ether, respectively. Stirring was carried out at room temperature, and the reaction progress was monitored by nuclear magnetic resonance hydrogen spectrum. After the reaction was completed, solid residues were removed by filtration, and the filtrate was concentrated under reduced pressure and then poured into methanol to precipitate a solid. The solid was collected by vacuum filtration, washed with cold methanol three times, and dried under vacuum to obtain the end-methyl polyphenylene ether solid product;

[0044] (2) Synthesis of side-chain brominated end-methyl polyphenylene ether: 1 eq of end-methyl polyphenylene ether was dissolved in carbon tetrachloride under argon atmosphere, and azobisisobutyronitrile and N-bromosuccinimide were added in sequence, the amount of which was 0.04 times and 0.5 times of the molar amount of end-methyl polyphenylene ether, respectively. The mixture was reacted at 60°C for 8 h, and then cooled to room temperature. Deionized water was added for dilution under stirring at 400 rpm. The organic phase was separated, poured into methanol to precipitate a solid, and the solid was collected by vacuum filtration and dried to obtain the side-chain brominated end-methyl polyphenylene ether solid product;

[0045] Trifluoromethylated acrylate hydroxyl compound 1: self-made, and the preparation method is as follows:

[0046] (1) Under nitrogen atmosphere, 1 eq of vacuum-dried tetra-bromobisphenol A was dissolved in anhydrous dichloromethane, and triethylamine, 4-dimethylamino pyridine and a polymerization inhibitor were added, the amount of which was 1.2 times, 0.02 times and 0.02 times of the molar amount of tetra-bromobisphenol A, respectively. After stirring uniformly, 2.2 times of the molar amount of acryloyl chloride of tetra-bromobisphenol A was slowly added dropwise under 0°C ice bath, and stirring was maintained for 30 min. Subsequently, the temperature was raised to room temperature and reacted for 4 h. After the reaction was completed, the system was poured into ice water for quenching, and the organic phase was collected and washed with 10% dilute hydrochloric acid, saturated sodium bicarbonate solution and deionized water in sequence until neutral. After drying with anhydrous sodium sulfate, the solvent was removed under reduced pressure, and the acrylate product was obtained by silica gel column chromatography purification and vacuum drying;

[0047] (2) Under nitrogen atmosphere, 1 eq of the acrylated product, 4.5 times of the molar amount of bis(pinacolato)diboron, potassium carbonate and 1,4-dioxane were mixed and degassed in a dry flask. Under light-proof conditions, a palladium catalyst and a polymerization inhibitor were added, and the amount of potassium carbonate, palladium catalyst and polymerization inhibitor was 3.3 times, 0.15 times and 0.02 times of the molar amount of the acrylated product, respectively. The mixture was reacted at 85°C for 24 h. After the reaction was completed, it was extracted with ethyl acetate, and the organic phases were combined and dried with anhydrous sodium sulfate. After concentration under reduced pressure, the borate ester compound was obtained by silica gel column chromatography purification;

[0048] (3) Under nitrogen atmosphere, the borate compound and para-bromotrifluorotoluene were dissolved in toluene at a molar ratio of (1.1-1.2):3, and after degassing for 15 minutes, a potassium carbonate aqueous solution was added, and degassed again for 15 minutes; then, 15 mol% palladium catalyst was added under light-proof conditions, and bubbling was performed to deoxygenate for 15 minutes. The mixture was reacted at 85°C for 24 hours; after the reaction, the mixture was extracted and separated with chloroform and water, and the organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography to obtain a trifluoromethylated pinacol ester product;

[0049] (4) Under nitrogen atmosphere, the trifluoromethylated pinacol ester product and 4-bromophenol were dissolved in toluene at a molar ratio of (1.1-1.3):1, and after nitrogen bubbling for deoxygenation for 15 minutes, a potassium carbonate aqueous solution was added, and degassed again for 15 minutes; under light-shielding conditions, a palladium catalyst equivalent to 0.10-0.15 times the molar amount of the trifluoromethylated pinacol ester product was added, and bubbling for deoxygenation for 15 minutes. The mixture was reacted at 95°C for 24 hours; after the reaction, the mixture was extracted and separated with chloroform and water, and the organic phase was washed with saturated brine, dried over anhydrous sodium sulfate, concentrated under reduced pressure, and purified by silica gel column chromatography to obtain a trifluoromethylated acrylate hydroxy compound 1, the structure of which is shown below:

[0050]

[0051] Trifluoromethylated acrylate hydroxy compound 2: homemade. The preparation method is similar to that of trifluoromethylated acrylate hydroxy compound 1, except that tetrabromobisphenol A in step (1) is replaced by 2,2-bis(3-bromo-4-hydroxyphenyl)propane, bis(pinacolato)diboron in step (2) is replaced by 4.5 times to 2.2 times, and para-bromotrifluorotoluene in step (3) is replaced by 3 times to 1 time. Other conditions remain unchanged, yielding trifluoromethylated acrylate hydroxy compound 2, the structure of which is shown below:

[0052]

[0053] Acrylate hydroxy compound 3: homemade. The preparation method is similar to that of trifluoromethylated acrylate hydroxy compound 1, except that para-bromotrifluorotoluene in step (3) is replaced by para-bromotoluene. Other conditions remain unchanged, yielding acrylate hydroxy compound 3, the structure of which is shown below:

[0054]

[0055] Mercaptosilane coupling agent modified spherical ceramic powder: homemade, the preparation method is as follows:

[0056] Mix 3 parts of water and 30 parts of ethanol, add 0.5 mol / L dilute hydrochloric acid dropwise to adjust the pH to 5, add 3 parts of mercaptosilane coupling agent, adjust the temperature to 30°C, and stir for 1 hour; add 60 parts of spherical ceramic powder to the above solution, stir for 1 hour, and then ultrasonically disperse for 1 hour, and remove the solvent to obtain spherical ceramic powder modified with mercaptosilane coupling agent.

[0057] Spherical ceramic powder: hollow spherical silica, 300-500 nm, purchased from Qinghe Chaotai Metal Materials Co., Ltd.

[0058] Mercaptosilane coupling agent: mercaptopropyltrimethoxysilane, product number M100619, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0059] Palladium catalyst: Tetrakis(triphenylphosphine)palladium, product number 1021232, purchased from Shanghai Haohong Biopharmaceutical Technology Co., Ltd.

[0060] Compatibilizer: ethylene-glycidyl methacrylate copolymer, model LOTADERAX8840, purchased from Shanghai Jingyan Chemical Co., Ltd.

[0061] Antioxidant: Antioxidant 1076, product number I811772, purchased from Shanghai MacLean Biochemical Technology Co., Ltd.

[0062] Release agent: Pentaerythritol tetrastearate, product number 1256254, purchased from Shanghai Haohong Biopharmaceutical Technology Co., Ltd.

[0063] Inhibitor: hydroquinone, product number H108945, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0064] Initiator: di-tert-butyl peroxide, product number B100924, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0065] Polyphenylene ether: purity 99.8%, molecular weight 15000-23000, product number 013629752, purchased from Shanghai Titan Technology Co., Ltd.

[0066] Azobisisobutyronitrile: Product No. A104255, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0067] N-Bromosuccinimide: Product No. B105057, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0068] Tetrabromobisphenol A: purity 98%, product number 1043843, purchased from Shanghai Haohong Biopharmaceutical Technology Co., Ltd.

[0069] Acryloyl chloride: product number A104614, purchased from Shanghai Aladdin Bio-Chem Technology Co., Ltd.

[0070] Bis(pinacolato)diboron: product number 1041001, purchased from Shanghai Hauhui Biomedical Technology Co., Ltd.

[0071] p-Bromobenzotrifluoride: product number 1031995, purchased from Shanghai Hauhui Biomedical Technology Co., Ltd.

[0072] 4-Bromophenol: product number M32059, purchased from Shanghai Maile Biotech Co., Ltd.

[0073] 2,2-Bis(3-bromo-4-hydroxyphenyl)propane: purity ≥98%, purchased from Wuhan Hejingxing Biotechnology Co., Ltd.

[0074] Preparation Example

[0075] Preparation Example 1

[0076] Modified polyphenyl ether 1: self-made, the preparation method is as follows:

[0077] 1 eq of the side chain brominated end methyl polyphenyl ether was dissolved in chlorobenzene and stirred; 0.5 times of the molar amount of the side chain brominated end methyl polyphenyl ether of trifluoromethylated acrylate hydroxyl compound 1, 1 times of the molar amount of the side chain brominated end methyl polyphenyl ether of potassium carbonate and 3 mL of dimethyl sulfoxide were sequentially added, and the mixture was stirred at 80°C for 20 h; after the reaction was completed, it was cooled to room temperature, filtered, and the filtrate was washed with deionized water, dried with anhydrous sodium sulfate, and then concentrated under reduced pressure; the concentrated solution was poured into methanol to precipitate the precipitate, which was purified by silica gel column chromatography to obtain modified polyphenyl ether 1.

[0078] Preparation Example 2

[0079] Modified polyphenyl ether 2: self-made, the preparation method is compared with that of modified polyphenyl ether 1, the difference is that trifluoromethylated acrylate hydroxyl compound 1 is replaced by trifluoromethylated acrylate hydroxyl compound 2, and other conditions are unchanged, to obtain modified polyphenyl ether 2.

[0080] Preparation Example 3

[0081] Modified polyphenyl ether 3: self-made, the preparation method is compared with that of modified polyphenyl ether 1, the difference is that trifluoromethylated acrylate hydroxyl compound 1 is replaced by acrylate hydroxyl compound 3, and other conditions are unchanged, to obtain modified polyphenyl ether 3.

[0082] Examples and comparative examples

[0083] Examples 1-4 and comparative examples 1-3

[0084] Composite dielectric materials 1-7: self-made, the preparation method is as follows:

[0085] S1. Mixing: 25 to 60 parts of modified polyphenylene ether 1 to 3, 30 to 60 parts of spherical ceramic powder modified with mercaptosilane coupling agent, 0.01 to 5 parts of compatibilizer, 0.5 to 3 parts of antioxidant, 0.5 to 2 parts of release agent, and 0.1 to 0.6 parts of initiator were added to a high-speed mixer and premixed at 1000 rpm for 15 min.

[0086] S2. Extrusion granulation: The temperature of each section of the twin-screw extruder is preheated to an appropriate range, the feed section temperature is set at 180°C, the compression section temperature at 200°C, and the metering section temperature at 220°C. Nitrogen is introduced into the extrusion hopper at a flow rate of 8 L / min; the mixed material is added to the extruder hopper, and the material is pushed by the screw and sequentially undergoes the processes of conveying, compression, melting, and mixing. The screw speed is controlled at 100 rpm so that the material is fully melted and mixed in the extruder and extruded from the die in a uniform strip shape; the extruded strip material is cooled by air to below 60°C and cut into low-dielectric spherical ceramic powder polyphenylene ether composite particles with a particle size of 1 to 2 mm by a pelletizer;

[0087] S3. Hot pressing: Select a stainless steel mold, clean and preheat it at 180°C; place the low-dielectric spherical ceramic powder polyphenylene ether composite particles into the preheated mold, and try to make the particles evenly distributed; place the mold containing the material into a hot press, and first maintain it at 8MPa and 180°C for 3 minutes to initially compact the material; then gradually increase the pressure to 15MPa, and at the same time increase the temperature to 190°C, and maintain it for 6 minutes, so that the composite particles are fully melted and fill the mold cavity to form a composite dielectric material of the desired shape; after the hot pressing is completed, while maintaining the pressure, air-cool the mold, so that the material is cooled to 80°C at a rate of 1-2°C / min, and then air-cooled to 50-60°C, and the molded low-dielectric spherical ceramic powder polyphenylene ether composite dielectric materials 1-7 are taken out.

[0088] Table 1 Formulas of Examples 1 to 4 and Comparative Examples 1 to 3 (by weight)

[0089]

[0090]

[0091] The following are the test methods for the performance parameters involved in the present invention:

[0092] 1. Nuclear magnetic resonance hydrogen spectrum test: The trifluoromethylated acrylate hydroxy compound 1 was characterized by a nuclear magnetic resonance spectrometer (Bruker AM-600, Advance 600).

[0093] 2. Dielectric properties: The dielectric constant and dielectric loss of the samples were tested at 1.0 GHz using an Agilent 4991A instrument. Each group of samples was tested three times, and the results were averaged with an error range of ±0.01.

[0094] 3. Flexural modulus: Tested in accordance with ASTM D790, with a span of 50 mm, a loading rate of 1.27 mm / min, and a specimen thickness of 3.2 mm. Each sample was tested three times, and the results were averaged with an error range of ±50 MPa.

[0095] 4. Impact strength: Tested in accordance with GB / T 1043.1-2008 standard, each group of samples was tested 3 times, and the results were averaged with an error range of ±1.0kJ / m 2 .

[0096] 5. Elongation at break: Tested in accordance with ASTM D638 at a speed of 50 mm / min. Each sample was tested three times and the average result was taken. The error range was ±0.5%.

[0097] The test results are shown in Table 2:

[0098] Table 2 Performance test results of Examples 1 to 4 and Comparative Examples 1 to 3

[0099]

[0100]

[0101] As can be seen from Table 2, trifluoromethyl is introduced into the matrix of modified polyphenylene ether 1 and 2, so that the dielectric constants of Examples 1 to 4 are all lower than those of Comparative Example 1 without trifluoromethyl and Comparative Example 2 of unmodified polyphenylene ether; at the same time, the steric hindrance effect of trifluoromethyl reduces the movement of molecular chain segments, thereby reducing the dielectric loss compared with Comparative Example 1; Comparative Example 3 uses unmodified ceramic powder, has poor interface compatibility, increased dielectric constant and loss, and decreased flexural modulus and impact strength. It is speculated that the mercaptosilane-modified spherical ceramic powder and the modified polyphenylene ether can form stable chemical crosslinks, which can effectively improve interface bonding and increase flexural modulus and impact strength.

[0102] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A low-dielectric spherical ceramic powder polyphenylene ether composite dielectric material for 5G substrates, characterized in that: The composition comprises, by weight, 25 to 60 parts of modified polyphenylene ether, 30 to 60 parts of spherical ceramic powder modified with a mercaptosilane coupling agent, 0.01 to 5 parts of a compatibilizer, 0.5 to 3 parts of an antioxidant, 0.5 to 2 parts of a release agent, and 0.1 to 0.6 parts of an initiator. The structure of the modified polyphenylene ether is shown in Formula 1: Formula 1, wherein the ratio of x to y is (2 to 5): (5 to 8).

2. The low-dielectric spherical ceramic powder polyphenylene ether composite dielectric material for 5G substrates according to claim 1, characterized in that: The preparation method of the spherical ceramic powder modified with a mercaptosilane coupling agent comprises the following steps: Water and ethanol are mixed in a weight ratio of (0.5-3): (8-30), the pH is adjusted to 4-6 with dilute hydrochloric acid, 0.5-3 parts of mercaptosilane coupling agent are added, the temperature is raised and stirred, spherical ceramic powder is added to the above solution, and after stirring, ultrasonic dispersion is performed to obtain spherical ceramic powder modified with mercaptosilane coupling agent.

3. The low-dielectric spherical ceramic powder polyphenylene ether composite dielectric material for 5G substrates according to claim 2, characterized in that: The mercaptosilane coupling agent is one or more of 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, and 11-mercaptoundecyltrimethoxysilane.

4. The low-dielectric spherical ceramic powder polyphenylene ether composite dielectric material for 5G substrates according to claim 2, characterized in that: The spherical ceramic powder includes one or more of spherical silicon dioxide, spherical aluminum oxide, spherical aluminum nitride, and spherical magnesium oxide.

5. The low-dielectric spherical ceramic powder polyphenylene ether composite dielectric material for 5G substrates according to claim 1, characterized in that: The preparation method of the modified polyphenylene ether comprises the following steps: The side chain brominated methyl-terminated polyphenylene ether is dissolved in chlorobenzene and stirred; a trifluoromethylated acrylate hydroxy compound equivalent to 0.2 to 0.5 times the molar amount of the side chain brominated methyl-terminated polyphenylene ether, potassium carbonate equivalent to 0.9 to 1.1 times the molar amount of the side chain brominated methyl-terminated polyphenylene ether, and dimethyl sulfoxide are added, and the temperature is increased and stirred; after the reaction is completed, the mixture is cooled to room temperature and purified to obtain a modified polyphenylene ether.

6. The low-dielectric spherical ceramic powder polyphenylene ether composite dielectric material for 5G substrates according to claim 5, characterized in that: The preparation method of the side chain brominated methyl-terminated polyphenylene ether comprises the following steps: (1) Synthesis of methyl-terminated polyphenylene ether: Under a nitrogen atmosphere, polyphenylene ether was dissolved in tetrahydrofuran, and iodomethane and potassium carbonate were added in amounts equivalent to 2.1 to 2.2 times and 2.4 to 2.5 times the molar amount of polyphenylene ether, respectively, and stirred. After the reaction was completed, the methyl-terminated polyphenylene ether was purified to obtain a solid product; (2) Synthesis of side chain brominated methyl-terminated polyphenylene ether: Under an argon atmosphere, the methyl-terminated polyphenylene ether was dissolved in carbon tetrachloride, and azobisisobutyronitrile and N-bromosuccinimide were added while stirring, and the amounts thereof were equivalent to 0.03 to 0.04 times and 0.2 to 0.5 times the molar amount of the methyl-terminated polyphenylene ether, respectively. The reaction was carried out at 55 to 65°C. After the reaction was completed, the side chain brominated methyl-terminated polyphenylene ether was purified to obtain the side chain brominated methyl-terminated polyphenylene ether.

7. The low-dielectric spherical ceramic powder polyphenylene ether composite dielectric material for 5G substrates according to claim 5, characterized in that: The preparation method of the trifluoromethylated acrylate hydroxy compound comprises the following steps: (1) Under a nitrogen atmosphere, vacuum-dried tetrabromobisphenol A is dissolved in anhydrous dichloromethane, and acryloyl chloride equivalent to 2.1 to 2.3 times the molar amount of tetrabromobisphenol A is slowly added dropwise in an ice bath, while maintaining low temperature and stirring. The mixture is then heated to room temperature for reaction. After the reaction is completed, the product is purified to obtain an acrylated product. (2) In a dry flask, the acrylic acid esterification product, bis(pinacolato)diboron (4.5 to 4.6 times the molar amount of the acrylic acid esterification product) and 1,4-dioxane were mixed and degassed under a nitrogen atmosphere. The mixture was reacted at 80 to 90° C. After the reaction, the borate compound was purified to obtain the borate compound. (3) Under a nitrogen atmosphere, the borate compound and para-bromotrifluorotoluene are dissolved in toluene at a molar ratio of (1.1-1.2):3, and after degassing, a potassium carbonate aqueous solution is added, and degassing is repeated; then, under light-shielding conditions, a palladium catalyst equivalent to 0.10-0.15 times the molar amount of the borate compound is added, and after deoxygenation, the reaction is carried out at 80-90°C; after the reaction, the trifluoromethylated pinacol ester product is purified; (4) Under a nitrogen atmosphere, the trifluoromethylated pinacol ester product and 4-bromophenol are dissolved in toluene at a molar ratio of (1.1-1.3):1, and after degassing, a potassium carbonate aqueous solution is added, and degassing is repeated; under light-shielding conditions, a palladium catalyst equivalent to 0.10-0.15 times the molar amount of the trifluoromethylated pinacol ester product is added, and after deoxygenation, the reaction is carried out at 80-110° C., and after the reaction is completed, purification is performed to obtain a trifluoromethylated acrylate hydroxy compound.

8. The method for preparing a trifluoromethylated acrylate hydroxy compound according to claim 7, wherein: The palladium catalyst is one or two of tetrakis(triphenylphosphine)palladium and 1,1'-bis(di-tert-butylphosphine)ferrocenedichloropalladium; the potassium carbonate aqueous solution is prepared by dissolving potassium carbonate in 0.5 mL of ultrapure water in an amount of 1 to 1.5 times the molar amount of the borate compound; in the step (1), triethylamine, 4-dimethylaminopyridine and a polymerization inhibitor are further added, and their amounts are 1.1 to 1.3 times, 0.01 to 0.02 times and 0.01 to 0.02 times the molar amount of tetrabromobisphenol A, respectively; in the step (2), potassium carbonate, a palladium catalyst and a polymerization inhibitor are further added under light-proof conditions, and their amounts are 3.0 to 3.5 times, 0.10 to 0.15 times and 0.01 to 0.02 times the molar amount of the acrylate product, respectively; the polymerization inhibitor is selected from hydroquinone.

9. The method for preparing a low-dielectric spherical ceramic powder polyphenylene ether composite dielectric material for 5G substrates according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Mixing: Premix 25-60 parts of modified polyphenylene ether, 30-60 parts of spherical ceramic powder modified with mercaptosilane coupling agent, 0.01-5 parts of compatibilizer, 0.5-3 parts of antioxidant, 0.5-2 parts of release agent, and 0.1-0.6 parts of initiator; S2 extrusion granulation: The twin-screw extruder feed section temperature, compression section temperature, metering section temperature were set, and nitrogen was introduced; the mixed material was added to the extruder hopper, melt extruded, and cut into low dielectric spherical ceramic powder polyphenylene ether composite particles; S3. Hot pressing: placing low-dielectric spherical ceramic powder polyphenylene ether composite particles into a mold, and hot pressing to obtain a low-dielectric spherical ceramic powder polyphenylene ether composite dielectric material.

10. The method for preparing a low-dielectric spherical ceramic powder polyphenylene ether composite dielectric material for 5G substrates according to claim 9, characterized in that: The temperature of the feeding section is set at 180-200°C, the temperature of the compression section is set at 200-220°C, and the temperature of the metering section is set at 220-235°C.

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