A method for preparing a nano high-frequency high-speed substrate

Abstract

This invention discloses a method for preparing a nano high-frequency high-speed substrate; belonging to the field of copper clad laminate substrate preparation technology; its key technical points include the following steps: (1) Mixing: Weigh 50-60 parts of liquid crystal bismaleimide / diallyl diphenyl ether copolymer, 20-30 parts of organic solvent, 17.5-30 parts of modified hexagonal nano boron nitride sheet KH570-BNNSs suspension, 1-2 parts of flame retardant, 0.2-0.5 parts of curing agent and 0.5-1.0 parts of coupling agent and pass through a mixture at 1500 rpm. (1) High-frequency high-speed adhesive is obtained by high-speed stirring for 2-4 hours; (2) Adhesive application: the low dielectric constant glass fiber cloth is unwound, initially impregnated with the high-frequency high-speed adhesive, and then impregnated on one side before being mainly impregnated to remove the air in the low dielectric constant glass fiber cloth. Then, it is extruded and dried in sequence to obtain a semi-cured sheet; (3) Assembly; (4) Pressing; The present invention aims to provide a method for preparing a nano high-frequency high-speed substrate with a scientific preparation method, high substrate strength and low water absorption rate; used for the preparation of copper clad laminate substrates.

Description

Technical Field

[0001] This invention relates to a method for preparing a substrate, and more specifically, to a method for preparing a nano-high-frequency, high-speed substrate. Background Technology

[0002] Currently, aramid paper is commonly used as the substrate in the preparation of nanopaper-based high-frequency and high-speed copper-clad laminates. This is because aramid fibers are produced by combining long and short fibers in papermaking. The resulting fibers have a non-ordered textile structure, and their structural strength is far lower than that of glass fiber cloth. During the sizing process, the lower structural strength of the aramid paper makes it prone to damage, gaps, and even breakage. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of the prior art by providing a scientific method for preparing a nano-high-frequency, high-speed substrate that yields a substrate with high strength and low water absorption.

[0004] The technical solution of this invention is achieved as follows: a method for preparing a nano-high-frequency, high-speed substrate, characterized by comprising the following steps:

[0005] (1) Mixing: Weigh 50-60 parts of liquid crystal bismaleimide / diallyl diphenyl ether copolymer, 20-30 parts of organic solvent, 17.5-30 parts of modified hexagonal boron nitride nanosheet KH570-BNNSs suspension, 1-2 parts of flame retardant, 0.2-0.5 parts of curing agent, and 0.5-1.0 parts of coupling agent, and stir at 1500 rpm for 2-4 hours to obtain high-frequency high-speed adhesive;

[0006] (2) Adhesive application: The low dielectric constant glass fiber cloth is unwound and initially impregnated with high-frequency and high-speed adhesive to wet one side. Then, it is subjected to a main impregnation to remove air from the low dielectric constant glass fiber cloth. Finally, it is extruded and dried to obtain a semi-cured sheet.

[0007] (3) Combination: Design and combine according to the required product thickness;

[0008] (4) Pressing: The assembled sheet materials are pressed and cured by a vacuum press.

[0009] In the above-mentioned method for preparing a nano high-frequency and high-speed substrate, the preparation of the modified hexagonal boron nitride nanosheet KH570-BNNSs suspension in step (1) is as follows: 4-10 parts of KH570 are added under the condition of 80-94 parts of isopropanol and stirred for 30 minutes. 2-10 parts of hexagonal boron nitride are added. Under the action of ultrasound, KH570 first undergoes alcoholysis to produce hydroxyl groups and then undergoes a dehydration reaction with hexagonal boron nitride to generate ether bonds, thereby obtaining the modified hexagonal boron nitride nanosheet KH570-BNNSs suspension.

[0010] In the above-mentioned method for preparing a nano high-frequency high-speed substrate, the weight-average molecular weight of the liquid crystal bismaleimide / diallyl diphenyl ether copolymer in step (1) is 5000-30000.

[0011] In the above-mentioned method for preparing a nano high-frequency high-speed substrate, the organic solvent in step (1) is one or any combination of dimethylacetamide, propylene glycol methyl ether acetate and N-methylpyrrolidone.

[0012] In the above-mentioned method for preparing a nano high-frequency high-speed substrate, the flame retardant in step (1) is one or any combination of antimony trioxide and tetrabromobisphenol A.

[0013] In the above-mentioned method for preparing a nano high-frequency high-speed substrate, the curing agent in step (1) is a bisphenol cyanate ester curing agent or a dicyclopentadiene cyanate ester curing agent with a weight-average molecular weight of 500-5000.

[0014] In the above-mentioned method for preparing a nano high-frequency high-speed substrate, the coupling agent in step (1) is one or any combination of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (KH-792) and γ-methacryloyloxypropyltrimethoxysilane (KH570).

[0015] In the above-mentioned method for preparing a nano high-frequency high-speed substrate, the low dielectric constant glass fiber cloth is one or two of 101 cloth, 1080 cloth, 2116 cloth, and NQ glass cloth 8176-Q.

[0016] In the above-mentioned method for preparing a nano high-frequency high-speed substrate, the drying step (2) specifically involves setting the oven temperature to 7 stages: the first stage is 145±5℃, the second stage is 160±5℃, the third stage is 175±5℃, the fourth stage is 195±5℃, the fifth stage is 210±5℃, the sixth stage is 185±5℃, and the seventh stage is 160±5℃. The moving speed is 4-8m / min. After drying, the substrate is cooled and cut to obtain a semi-cured sheet.

[0017] In the above-mentioned method for preparing a nano high-frequency high-speed substrate, step (4) specifically involves pressing the assembled board material into a vacuum press, heating it to 100℃ and holding it at that temperature for 0.5 hours, then heating it to 165℃-210℃ and holding it at that temperature for 1 hour, and finally pressing it at 260-300℃ for 3-4 hours, with the vacuum level controlled at 720-740 mmHg. The pressure is 30-50 MPa for pressing and curing.

[0018] This invention, employing the aforementioned technical solution, utilizes the double bonds inherent in the bismaleimide / diallyl diphenyl ether copolymer within the high-frequency, high-speed adhesive, and further combines this with the double bonds of the dicyclopentadiene-type cyanate system for crosslinking, thereby enhancing the crosslinking effect. Simultaneously, the introduction of an isocyanate coupling agent allows for crosslinking with the hydroxyl groups of modified hexagonal nano-boron nitride, effectively reducing the moisture absorption rate of the board by decreasing the presence of hydrophilic groups such as hydroxyl, carboxyl, and amino groups in the system. Furthermore, by replacing aramid paper with low-dielectric-constant glass fiber cloth 101 for coating and adhesive application, the shortcomings of insufficient strength and high water absorption rate of aramid paper boards are effectively addressed.

[0019] Testing revealed that the substrate obtained using the process of this invention has a Tg value of 250-290℃, a coefficient of thermal expansion ≤60ppm / ℃, a dielectric constant of 2-2.3, a dielectric loss of 0.006-0.02, a peel strength of 1.4-2.0N / mm, a bending strength of 240-270MPA, a thermal decomposition temperature ≥280℃, a moisture absorption rate ≤0.3%, and a breakdown voltage ≥170KV. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to embodiments, but this does not constitute any limitation on the present invention.

[0021] The present invention provides a method for preparing a nano-high-frequency, high-speed substrate, comprising the following steps:

[0022] (1) Mixing: Weigh 50-60 parts of liquid crystal bismaleimide / diallyl diphenyl ether copolymer, 20-30 parts of organic solvent, 17.5-30 parts of modified hexagonal boron nitride nanosheet KH570-BNNSs suspension, 1-2 parts of flame retardant, 0.2-0.5 parts of curing agent, and 0.5-1.0 parts of coupling agent, and stir at 1500 rpm for 2-4 hours to obtain high-frequency high-speed adhesive.

[0023] The modified hexagonal boron nitride nanosheets KH570-BNNSs suspension is prepared as follows: 4-10 parts of KH570 are added to 80-94 parts of isopropanol and stirred for 30 minutes. Then, 2-10 parts of hexagonal boron nitride are added. Under ultrasonic action, KH570 first undergoes alcoholysis to produce hydroxyl groups, which then undergo a dehydration reaction with hexagonal boron nitride to generate ether bonds, thus obtaining the modified hexagonal boron nitride nanosheets KH570-BNNSs suspension.

[0024] The liquid crystal bismaleimide / diallyl diphenyl ether copolymer has a weight-average molecular weight of 5000-30000.

[0025] The organic solvent is one or any combination of dimethylacetamide, propylene glycol methyl ether acetate, and N-methylpyrrolidone.

[0026] The flame retardant is one or any combination of antimony trioxide and tetrabromobisphenol A.

[0027] The curing agent is a bisphenol-type cyanate ester curing agent or a dicyclopentadiene-type cyanate ester curing agent, with a weight-average molecular weight of 500-5000.

[0028] The coupling agent is one or any combination of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (KH-792) and γ-methacryloyloxypropyltrimethoxysilane (KH570).

[0029] By utilizing the double bonds within the bismaleimide / diallyl diphenyl ether copolymer in high-frequency, high-speed adhesives, and further combining this with the double bonds of the dicyclopentadiene-type cyanate system for crosslinking, the crosslinking effect is improved. Simultaneously, the introduction of isocyanate coupling agents allows for crosslinking with the hydroxyl groups of modified hexagonal boron nitride nanoparticles, effectively reducing the moisture absorption rate of the board by minimizing the presence of hydrophilic groups such as hydroxyl, carboxyl, and amino groups in the system.

[0030] (2) Adhesive Application: The low dielectric constant fiberglass cloth is unwound and initially impregnated with high-frequency, high-speed adhesive, ensuring one side is wetted. Then, it undergoes a primary impregnation to remove air from the cloth. Next, it is sequentially extruded by extrusion rollers and dried in an oven. The oven temperature is set in seven stages: 145±5℃ for the first stage, 160±5℃ for the second, 175±5℃ for the third, 195±5℃ for the fourth, 210±5℃ for the fifth, 185±5℃ for the sixth, and 160±5℃ for the seventh. The moving speed is 4-8 m / min. After drying, the cloth is cooled and cut to obtain a semi-cured sheet. The semi-cured sheet contains 45-65% adhesive. The cured sheet is then cut to the corresponding dimensions according to production requirements, such as 1260*960mm, 1260*1060mm, and 1260*1112mm.

[0031] The low dielectric constant glass fiber cloth is one or two of 101 cloth, 1080 cloth, 2116 cloth and NQ glass cloth 8176-Q.

[0032] (3) Combination: Design and combine according to the required product thickness; for example, combine low profile high performance copper foil + several prepregs + low profile high performance copper foil.

[0033] (4) Pressing: The assembled sheet material is fed into a vacuum press, heated to 100℃ and held at that temperature for 0.5 hours, then heated to 165℃-210℃ and held at that temperature for 1 hour, and finally pressed at 260-300℃ for 3-4 hours, with the vacuum degree controlled at 720-740 mmHg. The pressure is 30-50 MPa for pressing and curing.

[0034] Example 1

[0035] The present invention provides a method for preparing a nano-high-frequency, high-speed substrate, comprising the following steps:

[0036] (1) Mixing: Weigh 50 kg of liquid crystal bismaleimide / diallyl diphenyl ether copolymer with a weight average molecular weight of 5000, 20 kg of dimethylacetamide, 17.5 kg of modified hexagonal boron nitride nanosheet KH570-BNNSs suspension, 1 kg of antimony trioxide, 0.2 kg of bisphenol cyanate ester curing agent with a weight average molecular weight of 500, and 0.5 kg of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and stir at 1500 rpm for 2 hours to obtain a high-frequency high-speed adhesive.

[0037] The modified hexagonal boron nitride nanosheets KH570-BNNSs suspension is prepared as follows: 4 kg of KH570 is added to 80 kg of isopropanol and stirred for 30 minutes. Then, 2 kg of hexagonal boron nitride is added. Under the action of ultrasound, KH570 first undergoes alcoholysis to produce hydroxyl groups, which then undergo a dehydration reaction with hexagonal boron nitride to generate ether bonds, thus obtaining the modified hexagonal boron nitride nanosheets KH570-BNNSs suspension.

[0038] (2) Adhesive application: The 101 fabric is unwound and initially impregnated with high-frequency, high-speed adhesive, ensuring one side is wetted. Then, it undergoes a primary impregnation to remove air from the fabric. Next, it is sequentially extruded by extrusion rollers and dried in an oven. The oven temperature is set in seven stages: 145±5℃ for the first stage, 160±5℃ for the second, 175±5℃ for the third, 195±5℃ for the fourth, 210±5℃ for the fifth, 185±5℃ for the sixth, and 160±5℃ for the seventh. The moving speed is 4m / min. After drying, the fabric is cooled and cut to obtain a semi-cured sheet. The semi-cured sheet contains 65% adhesive. The semi-cured sheet is cut into 1260*960mm pieces.

[0039] (3) Combination: Combine 1 low-profile high-performance copper foil + 6 prepregs + 1 low-profile high-performance copper foil.

[0040] (4) Pressing: The assembled board material is fed into a vacuum press, heated to 100℃ and held at that temperature for 0.5 hours, heated to 165℃ and held at that temperature for 1 hour, and then pressed at 260℃ for 4 hours with the vacuum degree controlled at 720 mmHg. The pressure is 30 MPa for pressing and curing to obtain a 0.3 mm substrate.

[0041] Example 2

[0042] A method for preparing a nano-high-frequency, high-speed substrate includes the following steps:

[0043] (1) Mixing: Weigh 55 kg of liquid crystal bismaleimide / diallyl diphenyl ether copolymer with a weight average molecular weight of 18000, 25 kg of propylene glycol methyl ether acetate, 23 kg of modified hexagonal boron nitride nanosheet KH570-BNNSs suspension, 1.5 kg of tetrabromobisphenol A, 0.3 kg of dimercyclopentadiene cyanate curing agent with a weight average molecular weight of 2500, and 0.8 kg of N-(β-aminoethyl)-Y-aminopropyltrimethoxysilane (KH-792) and stir at 1500 rpm for 3 hours to obtain a high-frequency high-speed adhesive.

[0044] The modified hexagonal boron nitride nanosheets KH570-BNNSs suspension was prepared as follows: 7 kg of KH570 was added to 87 kg of isopropanol and stirred for 30 minutes. Then, 6 kg of hexagonal boron nitride was added. Under the action of ultrasound, KH570 first underwent alcoholysis to produce hydroxyl groups, and then reacted with hexagonal boron nitride to form ether bonds, thus obtaining the modified hexagonal boron nitride nanosheets KH570-BNNSs suspension.

[0045] (2) Adhesive application: The 1080 fabric is unwound and initially impregnated with high-frequency, high-speed adhesive, ensuring one side is wetted. Then, it undergoes a primary impregnation to remove air from the fabric. Next, it is sequentially extruded by extrusion rollers and dried in an oven. The oven temperature is set in seven stages: 145±5℃ for the first stage, 160±5℃ for the second, 175±5℃ for the third, 195±5℃ for the fourth, 210±5℃ for the fifth, 185±5℃ for the sixth, and 160±5℃ for the seventh. The moving speed is 6 m / min. After drying, the fabric is cooled and cut to obtain a semi-cured sheet. The semi-cured sheet contains 55% adhesive. The cured sheet is cut into 1260*1060mm pieces.

[0046] (3) Combination: Combine 1 low-profile high-performance copper foil + 4 prepregs + 1 low-profile high-performance copper foil.

[0047] (4) Pressing: The assembled board material is fed into a vacuum press, heated to 100℃ and held at that temperature for 0.5 hours, heated to 185℃ and held at that temperature for 1 hour, and then pressed at 280℃ for 3.5 hours with the vacuum degree controlled at 730 mmHg. The pressure is 40 MPa for pressing and curing to obtain a 0.3 mm substrate.

[0048] Example 3

[0049] A method for preparing a nano-high-frequency, high-speed substrate includes the following steps:

[0050] (1) Mixing: Weigh 60 kg of liquid crystal bismaleimide / diallyl diphenyl ether copolymer with a weight average molecular weight of 30,000, 30 kg of N-methylpyrrolidone, 30 kg of modified hexagonal boron nitride nanosheet KH570-BNNSs suspension, 2 kg of tetrabromobisphenol A, 0.5 kg of dicyclopentadiene cyanate curing agent with a weight average molecular weight of 5,000, and 1.0 kg of γ-methacryloyloxypropyltrimethoxysilane (KH570). Stir at 1500 rpm for 4 hours to obtain a high-frequency high-speed adhesive.

[0051] The modified hexagonal boron nitride nanosheets KH570-BNNSs suspension is prepared as follows: 10 kg of KH570 is added to 94 kg of isopropanol and stirred for 30 minutes. Then, 10 kg of hexagonal boron nitride is added and subjected to ultrasonic treatment. KH570 first undergoes alcoholysis to produce hydroxyl groups, which then react with hexagonal boron nitride to form ether bonds, thus obtaining the modified hexagonal boron nitride nanosheets KH570-BNNSs suspension.

[0052] (2) Adhesive application: The 2116 fabric is unwound and initially impregnated with high-frequency, high-speed adhesive, ensuring one side is wetted. Then, it undergoes a primary impregnation to remove air from the fabric. Next, it is sequentially extruded by extrusion rollers and dried in an oven. The oven temperature is set in seven stages: 145±5℃ for the first stage, 160±5℃ for the second, 175±5℃ for the third, 195±5℃ for the fourth, 210±5℃ for the fifth, 185±5℃ for the sixth, and 160±5℃ for the seventh. The moving speed is 8 m / min. After drying, the fabric is cooled and cut to obtain a semi-cured sheet. The semi-cured sheet contains 45% adhesive. The cured sheet is cut into 1260*1112mm pieces.

[0053] (3) Combination: Combine 1 low-profile high-performance copper foil + 2 prepregs + 1 low-profile high-performance copper foil.

[0054] (4) Pressing: The assembled board material is fed into a vacuum press, heated to 100℃ and held at that temperature for 0.5 hours, heated to 210℃ and held at that temperature for 1 hour, and then pressed at 300℃ for 4 hours with the vacuum degree controlled at 740 mmHg. The pressure is 50 MPa for pressing and curing to obtain a 0.3 mm substrate.

[0055] The table below compares the performance parameters of the substrates obtained in the three embodiments with those obtained in the prior art. The results are shown in the table below.

[0056] Table 1 Performance Comparison Table

[0057] project Existing boards Example 1 Example 2 Example 3 standard Peel strength 0.82 1.35 1.21 1.07 ≥1.05N / mm flexural strength 172 247 256 270 ≥242MPa Tg value 235 260 253 262 250-290℃ coefficient of thermal expansion 42.4 23.8 27.3 17.4 ≤60ppm / ℃ Thermal decomposition temperature 275 292 287 308 ≥280℃ Dielectric constant 3.24 2.94 3.05 3.12 ≤3.5 Dielectric loss 0.02 0.008 0.011 0.015 ≤0.02

[0058] Comparing the performance in Table 1, Examples 1, 2, and 3 show significant improvements over existing boards in peel strength, flexural strength, Tg value, coefficient of thermal expansion, thermal decomposition temperature, dielectric constant, and dielectric loss. This is particularly evident in dielectric loss, peel strength, and flexural strength.

[0059] The above-described embodiments are preferred embodiments of the present invention and are only used to facilitate the illustration of the present invention. They are not intended to limit the present invention in any way. Any person skilled in the art who makes local modifications or alterations to the technical content disclosed in the present invention without departing from the scope of the technical features of the present invention shall still fall within the scope of the technical features of the present invention.

Claims

1. A method for manufacturing a nano high-frequency high-speed substrate, characterized by, Includes the following steps: (1) Mixing: Weigh 50-60 parts of liquid crystal bismaleimide / diallyl diphenyl ether copolymer, 20-30 parts of organic solvent, 17.5-30 parts of modified hexagonal boron nitride nanosheet KH570-BNNSs suspension, 1-2 parts of flame retardant, 0.2-0.5 parts of curing agent, and 0.5-1.0 parts of coupling agent, and stir at 1500 rpm for 2-4 hours to obtain high-frequency high-speed adhesive; The modified hexagonal boron nitride nanosheet KH570-BNNSs suspension is prepared as follows: 4-10 parts of KH570 are added to 80-94 parts of isopropanol and stirred for 30 minutes. Then 2-10 parts of hexagonal boron nitride are added. Under the action of ultrasound, KH570 first undergoes alcoholysis to produce hydroxyl groups, and then undergoes a dehydration reaction with hexagonal boron nitride to generate ether bonds, thus obtaining the modified hexagonal boron nitride nanosheet KH570-BNNSs suspension. (2) Adhesive application: The low dielectric constant glass fiber cloth is unwound and initially impregnated with high frequency and high speed adhesive to wet one side. Then, it is mainly impregnated to remove the air in the low dielectric constant glass fiber cloth. Then, it is extruded and dried in sequence to obtain a semi-cured sheet. (3) Combination: Design and combine products according to the required thickness; (4) Pressing: The assembled sheet material is pressed and cured by a vacuum press.

2. The method of claim 1, wherein the nanometer high-frequency high-speed substrate is prepared by the steps of: The weight-average molecular weight of the liquid crystal bismaleimide / diallyl diphenyl ether copolymer in step (1) is 5000-30000. ​ 3. The method for preparing a nano-high-frequency, high-speed substrate according to claim 1, characterized in that, The organic solvent in step (1) is one or any combination of dimethylacetamide, propylene glycol methyl ether acetate and N-methylpyrrolidone.

4. The method for preparing a nano-high-frequency, high-speed substrate according to claim 1, characterized in that, The flame retardant in step (1) is one or any combination of antimony trioxide and tetrabromobisphenol A.

5. The method for preparing a nano-high-frequency, high-speed substrate according to claim 1, characterized in that, The curing agent in step (1) is a bisphenol cyanate ester curing agent or a dicyclopentadiene cyanate ester curing agent with a weight-average molecular weight of 500-5000.

6. The method of claim 1, wherein the nanometer high-frequency high-speed substrate is prepared by the steps of: The coupling agent in step (1) is one or any combination of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and γ-methacryloyloxypropyltrimethoxysilane. ​ 7. The method of claim 1, wherein the nanometer high-frequency high-speed substrate is prepared by a method comprising: The low dielectric constant glass fiber cloth is one or two of 101 cloth, 1080 cloth and 2116 cloth. ​ 8. The method for preparing a nano-high-frequency, high-speed substrate according to claim 1, characterized in that, The drying process in step (2) involves setting the oven temperature to seven levels: 145±5℃ for the first level, 160±5℃ for the second level, 175±5℃ for the third level, 195±5℃ for the fourth level, 210±5℃ for the fifth level, 185±5℃ for the sixth level, and 160±5℃ for the seventh level. The moving speed is 4-8 m / min. After drying, the oven is cooled and cut to obtain a semi-cured sheet.

9. The method for preparing a nano-high-frequency, high-speed substrate according to claim 1, characterized in that, The pressing in step (4) specifically involves feeding the assembled sheet material into a vacuum press, heating it to 100℃ and holding it at that temperature for 0.5 hours, heating it to 165℃-210℃ and holding it at that temperature for 1 hour, and pressing it at 260-300℃ for 3-4 hours. The vacuum degree is controlled at 720-740 mmHg, and the pressure is 30-50 MPa for pressing, curing, and molding.