CN111825955A

CN111825955A - High-frequency prepreg, preparation method thereof, copper-clad plate and preparation method thereof

Info

Publication number: CN111825955A
Application number: CN202010715729.2A
Authority: CN
Inventors: 汪国庆; 王泽�; 方志强; 王皓民; 江昊; 杨宇
Original assignee: Hainan University
Current assignee: Hainan University
Priority date: 2020-07-23
Filing date: 2020-07-23
Publication date: 2020-10-27
Anticipated expiration: 2040-07-23
Also published as: CN111825955B

Abstract

The invention discloses a prepreg for high frequency, a preparation method thereof, a copper-clad plate and a preparation method thereof, wherein (1) basalt fibers and aramid fibers are co-copied to form fiber cloth, and high-pressure treatment is carried out under the action of high temperature and high pressure; (2) dipping the paper-making cloth in 50% solid content glue solution consisting of dicyclopentadiene phenol epoxy modified cyanate ester, novolac epoxy resin, heat conducting powder, crosslinking agent triallyl isocyanurate (TAIC) and xylene, dipping for 30-90 seconds, and drying at 120-260 ℃ to form a prepreg; (3) and laminating the prepreg and the copper foil for hot press molding. Therefore, the high-performance aramid fiber/basalt fiber-based copper-clad plate which meets the requirements of low dielectric constant and low dielectric loss tangent value for high-frequency use, good heat resistance, high thermal decomposition temperature and thermal shock resistance, good tensile strength and peel strength, excellent interfacial shear strength and excellent dimensional stability is prepared.

Description

High-frequency prepreg, preparation method thereof, copper-clad plate and preparation method thereof

Technical Field

The invention belongs to the technical field of electronic equipment substrates, and particularly relates to a high-frequency prepreg, a preparation method thereof, a copper-clad plate and a preparation method thereof.

Background

Nowadays, the development trend of global information technology is increasingly fierce, digitalization, informatization and networking are deeply applied to various industries and fields, and a new round of scientific and technological revolution and industrial change are caused by the cross development of technologies in various fields such as new energy technology, new material technology, biotechnology and the like. Meanwhile, the key for restricting the development of the informatization technology lies in the information bearing, transmission and processing capabilities of the electronic equipment. Among them, higher performance requirements are put forward for Printed Circuit Boards (PCBs) in basic electronic devices, and requirements for flame retardancy, insulation properties, and heat resistance of PCBs are more stringent while the development of electronic technologies is satisfied.

Printed circuit boards on electronic equipment widely used in China are traditional copper clad plates, and when the printed circuit boards are used as base materials of high-frequency and high-performance printed circuit boards, the problems of low moisture resistance, poor dielectric property, high thermal expansion rate and the like are caused due to mature basic processes such as epoxy resin/glass cloth and the like. In order to meet the application requirements of aerospace electronic equipment, military defense and military weapon communication equipment, the development of a high-performance copper-clad plate meeting the requirements of low dielectric constant, low dielectric loss tangent value, good heat resistance, high glass transition temperature, good tensile strength, excellent interface shear strength and excellent dimensional stability in high-frequency use is urgent.

Disclosure of Invention

The invention aims to provide a curing sheet for high frequency, a preparation method thereof, a copper-clad plate and a preparation method thereof, wherein the copper-clad plate prepared by the curing sheet has low dielectric constant (2.8-3.6), low dielectric loss tangent value (0.0059-0.0071), good heat resistance, high thermal decomposition temperature (320.62-340.61 ℃) and thermal shock resistance, good tensile strength and peel strength (2.0-2.7N/mm), excellent interface shear strength and excellent dimensional stability, and the high-performance aramid fiber/basalt fiber-based copper-clad plate is high in strength.

The invention provides a high-frequency prepreg, which comprises a fiber cloth core and a resin coating, wherein the resin coating is dipped and coated on the surface of the fiber cloth core;

the fiber cloth core is made of basalt fibers and aramid fibers, the resin coating is obtained by drying resin glue solution, and the resin glue solution comprises the following components in parts by weight:

dicyclopentadiene phenol epoxy-modified cyanate ester: 15-30 parts by weight of novolac epoxy resin: 30-60 parts by weight of heat-conducting powder: 5-10 parts by weight of a cross-linking agent: 5-15 parts by weight of a solvent: 30 to 50 parts by weight.

Preferably, the fiber cloth core is prepared according to the following steps:

aramid pulp, basalt fiber, 10-30 wt% of phosphoric acid-treated aramid fiber and water are mixed according to the weight ratio of 1: (1-5), adding a dispersing agent after mixing, adding an aqueous adhesive after uniformly dispersing, making into paper, forming, and drying in vacuum to obtain a fiber cloth core;

the weight ratio of the 10-30 wt% of the aramid fiber treated by the phosphoric acid to the aramid pulp, the basalt fiber, the dispersing agent and the water-based adhesive is (10-80): (5-50): (5-20): (1-5): (1-5).

Preferably, the dicyclopentadiene phenol epoxy modified cyanate ester is prepared according to the following steps:

and melting the cyanate ester resin, adding dicyclopentadiene phenol epoxy resin, reacting at 120-180 ℃ for 60-90 min, cooling to 80-100 ℃, adding dibutyltin dilaurate, and continuing to react to obtain the dicyclopentadiene phenol epoxy modified cyanate ester.

Preferably, the heat conducting powder is one or more of hexagonal boron nitride, aluminum oxide, spherical aluminum nitride and boron aluminate whiskers.

Preferably, the heat conducting powder is added into the resin glue solution after ball milling, drying and silane surface treatment in sequence.

Preferably, the crosslinking agent is one or more of triallyl isocyanurate, dicumyl peroxide and trimethylolpropane triacrylate.

The preparation method of the prepreg for high frequency as described above comprises the following steps:

and dip-coating the fiber cloth core in the resin glue solution for 30-90 s, and drying at 120-260 ℃ to obtain the high-frequency curing sheet.

The invention provides a copper-clad plate, which comprises a copper foil and a prepreg compounded on the surface of the copper foil;

the prepreg is the prepreg for high frequency described above.

The invention provides a preparation method of the copper-clad plate, which comprises the following steps:

and overlapping at least one prepreg and the copper foil, and carrying out hot pressing after vacuumizing treatment to obtain the copper-clad plate.

Preferably, the hot pressing temperature is 120-300 ℃, the hot pressing time is 2-8 h, and the hot pressing pressure is 1-50 MPa.

The invention provides a prepreg for high frequency, which comprises a fiber cloth core and a resin coating, wherein the resin coating is dipped and coated on the surface of the fiber cloth core; the fiber cloth core is made of basalt fibers and aramid fibers, the resin coating is obtained by drying resin glue solution, and the resin glue solution comprises the following components in parts by weight: dicyclopentadiene phenol epoxy-modified cyanate ester: 15-30 parts by weight of novolac epoxy resin: 30-60 parts by weight of heat-conducting powder: 5-10 parts by weight of a cross-linking agent: 5-15 parts by weight of a solvent: 30 to 50 parts by weight. The aramid fiber/basalt fiber papermaking cloth is prepared by utilizing the excellent heat resistance, flame retardance, insulativity and mechanical properties of the aramid fiber and the basalt fiber through the complex phase synergistic effect. The preparation method comprises the steps of preparing a semi-solid sheet by using dicyclopentadiene phenol epoxy modified cyanate ester and novolac epoxy resin composite resin with low dielectric constant, low dielectric loss, low water absorption and good flame retardance as a glue solution matrix, and preparing the aramid fiber/basalt fiber semi-solid sheet for high frequency and the high-performance copper-clad plate through superposition and hot-pressing treatment.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is an SEM image (500 times magnified) of pre-treated aramid chopped fibers, aramid pulp and basalt fibers mixed and then treated and formed by papermaking in example 6 of the invention;

FIG. 2 is an SEM image (1000 times magnification) of pre-treated aramid chopped fibers, aramid pulp and basalt fibers mixed and then treated and formed by papermaking in example 6 of the present invention;

fig. 3 is an SEM image of the pretreated aramid chopped fibers, aramid pulp, and basalt fiber mixed post-treatment coating resin forming a coating in example 6 of the present invention.

Detailed Description

The invention provides a prepreg for high frequency, which comprises a fiber cloth core and a resin coating, wherein the resin coating is dipped and coated on the surface of the fiber cloth core;

In the invention, the thickness of the fiber cloth core is preferably 40-100 μm, more preferably 50-90 μm, and most preferably 60-80 μm; the thickness of the resin coating is preferably 10-50 μm, more preferably 20-40 μm, and most preferably 20-30 μm; the thickness of the high-frequency prepreg is preferably 50 to 150 μm, more preferably 70 to 130 μm, and most preferably 80 to 110 μm.

In the invention, the fiber cloth core is made of basalt fiber and aramid fiber, and the preparation process comprises the following steps:

firstly, the aramid fiber is subjected to surface treatment by using phosphoric acid.

Firstly, ultrasonically cleaning aramid fibers with acetone for 2-3 hours, then drying, treating with a phosphoric acid solution, then repeatedly cleaning with distilled water to the center, and drying to obtain the aramid fibers treated with phosphoric acid.

In the invention, the mass concentration of the phosphoric acid solution is preferably 10-30%, more preferably 20%, the treatment time of the phosphoric acid solution is preferably 10-15 min, and the treatment temperature is preferably 40-60 ℃, more preferably 50 ℃.

The main purposes of the invention for treating aramid fiber by using phosphoric acid are as follows:

the oxygen content and the hydroxyl content of the surface of the aramid fiber treated by the phosphoric acid are increased, the polarity of the surface of the fiber is increased, and the fiber and a resin matrix show better compatibility (the combination between the fiber and the resin matrix mainly comprises a polar functional group on the surface of the fiber and the adsorption effect of the resin matrix).

And secondly, the wettability between the aramid fiber and the resin after the phosphoric acid treatment is improved.

The surface roughness of the aramid fiber after phosphoric acid treatment is increased, the mechanical interlocking effect between the fiber and the matrix is increased, and the interface bonding capability is improved.

In the invention, the drying temperature is preferably 80-120 ℃, more preferably 90-110 ℃, and most preferably 100 ℃; the drying time is preferably 3-10 hours, and more preferably 5-8 hours; the drying pressure is preferably 1 to 10Kpa, more preferably 2 to 8Kpa, and most preferably 4 to 6 Kpa.

And then, the aramid fiber, the basalt fiber and the aramid fiber pulp after the phosphoric acid treatment are molded by papermaking.

Aramid pulp, basalt fiber, 10-30 wt% of phosphoric acid-treated aramid fiber and water are mixed according to the weight ratio of 1: and (1) mixing the raw materials according to the proportion of (1) to (5), adding a dispersing agent, uniformly dispersing, adding an aqueous adhesive, making the obtained mixed solution into paper, forming, and drying in vacuum to obtain the fiber cloth core.

Preferably, the aramid pulp, basalt fibers, 10-30 wt% of phosphoric acid-treated aramid fibers and water are mixed according to the weight ratio of 1: (1-5), adding a dispersing agent for defibering to uniformly disperse various fibers in water, finally adding an aqueous binder to obtain a mixed solution, then using an automatic paper machine for papermaking and molding, performing vacuum drying, and performing surface high-pressure polishing treatment to obtain a fiber cloth core.

In the invention, the aramid pulp is obtained after surface fibrillation treatment is carried out on aramid fibers, and the unique surface structure greatly improves the holding power of the mixture, so that the aramid pulp is very suitable to be used as a reinforcing fiber in friction and sealing products. The aramid fiber pulp is softer, the surface is broomed, the crosslinking and combination between the aramid fiber and the resin matrix are tighter, and the overall performance is improved. The mass fraction of the aramid pulp in the mixed solution is preferably 5-50%, more preferably 10-40%, more preferably 15-35%, and most preferably 20-30%.

The basalt fiber is preferably basalt fiber roving, is formed by combining a plurality of parallel strands or single-stranded parallel strands in a non-twisted state, and is synergistically acted with the aramid fiber to toughen the composite fiber. The mass fraction of the basalt fibers in the mixed solution is preferably 5-20%, and more preferably 10-15%.

In the invention, the mass fraction of the aramid fiber after the phosphoric acid treatment in the mixed solution is preferably 10-80%, more preferably 20-70%, most preferably 30-60%, and most preferably 40-50%.

In the invention, the mass ratio of the aramid pulp, the basalt fiber and the phosphoric acid-treated aramid fiber is preferably (5-50): (5-20): (10-80), preferably (10-40): (10-15): (20-70), specifically, in the embodiment of the present invention, the ratio may be 60: 30: 10. 40: 40: 20. 50: 30: 20 or 60: 20: 20.

in the invention, the dispersant is preferably one or more of polyacrylamide, polyethylene glycol and polyvinyl alcohol; the mass fraction of the dispersant in the mixed solution is preferably 1-5%, more preferably 2-4%, and most preferably 3%. After the dispersing agent is added, the solution is defibered by an LW standard defibering machine, and the rotational speed of the defibering is preferably 5000-50000 rpm.

In the invention, the aqueous binder is preferably one or more of polyvinyl alcohol, guar gum and aqueous polyurethane; the mass fraction of the aqueous binder in the mixed solution is preferably 1-5%, more preferably 2-4%, and most preferably 3%.

In the invention, the temperature of vacuum drying after paper making and forming is preferably 120-260 ℃, and more preferably 150-200 ℃; the vacuum drying time is preferably 20-40 min, and more preferably 30-35 min; the vacuum degree of the vacuum drying is preferably 10⁵～10²Pa, more preferably 10⁴～10³Pa。

In the invention, the pressure intensity of the high-pressure polishing treatment is preferably 5-30 MPa, more preferably 10-25 MPa, and most preferably 15-20 MPa; the high-pressure polishing treatment temperature is preferably 40-260 ℃, more preferably 50-250 ℃, and most preferably 100-200 ℃; the time of the high-pressure polishing treatment is preferably 10-40 min, and more preferably 20-30 min.

In the invention, the resin glue solution preferably comprises the following components in parts by weight:

dicyclopentadiene phenol epoxy-modified cyanate ester: 15-30 parts by weight, preferably 20-25 parts by weight, specifically, in the embodiment of the present invention, 20 parts by weight, 25 parts by weight, or 30 parts by weight;

phenolic epoxy resin: 30 to 60 parts by weight, preferably 35 to 55 parts by weight, more preferably 40 to 50 parts by weight, specifically, in the embodiment of the present invention, 30 parts by weight, 35 parts by weight, 45 parts by weight;

heat-conducting powder: 5 to 10 parts by weight, preferably 6 to 9 parts by weight, more preferably 7 to 8 parts by weight, specifically, 6 parts by weight, 5 parts by weight, 8 parts by weight, 10 parts by weight in the embodiment of the present invention;

a crosslinking agent: 5 to 15 parts by weight, preferably 8 to 12 parts by weight, and most preferably 10 to 12 parts by weight; specifically, in the embodiment of the present invention, the amount may be 5 parts by weight, 10 parts by weight, 14 parts by weight;

solvent: 30 to 50 parts by weight, more preferably 35 to 45 parts by weight, and most preferably 40 parts by weight, and specifically, in the embodiment of the present invention, 30 parts by weight, 35 parts by weight, and the like may be mentioned.

The solid content of the resin glue solution is preferably 40-70%, and more preferably 50-60%.

In the invention, the dicyclopentadiene phenol epoxy modified cyanate ester is prepared by the following steps:

and melting cyanate ester resin, adding dicyclopentadiene phenol epoxy resin, stirring at 120-180 ℃, reacting for 60-90 min, cooling to 80-100 ℃, adding dibutyltin dilaurate, and continuing to react to obtain the homogeneous transparent brown dicyclopentadiene phenol epoxy modified cyanate ester.

In the present invention, the mass ratio of the cyanate ester to the dicyclopentadiene phenol epoxy resin is preferably 1: (1-5), more preferably 1 (2-4), and most preferably 1: (2-3); the mass ratio of the dibutyltin dilaurate to the cyanate ester resin is preferably (0.1-0.3%): 1.

in the invention, the melting temperature of the cyanate ester resin is preferably 140-160 ℃, and more preferably 150 ℃; the reaction temperature is preferably 120-180 ℃, more preferably 130-170 ℃, and most preferably 140-160 ℃, and specifically, in the embodiment of the invention, the reaction temperature can be 150 ℃; the reaction time is preferably 60-90 min, more preferably 70-80 min, and most preferably 75 min; the temperature for cooling is preferably 80-100 ℃, more preferably 90 ℃, and the dibutyltin dilaurate is added, and then the stirring reaction is continued for 15-20 min.

The resin matrix of the resin glue solution is dicyclopentadiene phenol epoxy modified cyanate ester and novolac epoxy resin. The dicyclopentadiene phenol epoxy resin has extremely high cohesiveness, extremely low hygroscopicity, low dielectric constant and dielectric loss tangent, high heat resistance, and the cured resin shows excellent heat resistance and chemical stability. The dicyclopentadiene phenol epoxy resin modified by polyurethane can further reduce the thermal expansion coefficient and the water absorption of a cured resin and the chemical stability of the cured resin. Meanwhile, the compressive strength, the impact resistance, the toughness and the wear resistance of the original dicyclopentadiene phenol epoxy resin are improved.

The phenolic resin has the advantages of low cost, simple production and processing, high strength of a cured product, excellent high temperature resistance, corrosion resistance and flame resistance, and high thermal deformation temperature.

In the invention, the heat-conducting powder is preferably one or more of hexagonal boron nitride, alumina, sphericized aluminum nitride and boron aluminate whiskers; according to the invention, the silane coupling agent is preferably used for modifying the heat-conducting powder, and then the modified heat-conducting powder is added into the resin glue solution for impregnation.

The specific modification method comprises the following steps:

mixing the heat-conducting powder with ethanol, carrying out ball milling, then drying, and finally modifying the heat-conducting powder after ball milling and drying by using a silane coupling agent to obtain the silane modified heat-conducting powder.

The heat conducting powder is ball milled. The nano-particles are uniformly dispersed in the matrix material, and the improvement of the heat conductivity coefficient is facilitated. The silane coupling agent is preferably one or more of KH550, 3-isocyanatopropyl-trimethoxysilane and 3-isocyanatopropyl-triethoxysilane. After silane surface treatment, the inorganic reinforcing material such as heat conducting powder and thermosetting resin are made into composite material, and the inorganic matter and the polymer are connected to obtain optimal wetting value and dispersivity.

In the invention, the crosslinking agent is preferably one or more of triallyl isocyanurate (TAIC), dicumyl peroxide (DCP), dicumyl peroxide (BIPB) and trimethylolpropane triacrylate (RMPTA).

In the present invention, the solvent is preferably one or more of xylene, toluene, acetone and ethanol.

The invention also provides a preparation method of the prepreg for high frequency, which comprises the following steps:

In the present invention, the components, types and usage amounts of the fiber cloth core and the resin glue solution are the same as those of the fiber cloth core and the resin glue solution, and are not described herein again.

Preferably, the fiber cloth core is gently placed in the resin glue solution, one side of the fiber cloth core gradually contacts the glue until the fiber cloth core is completely dipped in the glue solution for about 30-90 s, then the fiber cloth core is taken out, stands and dries, and then the fiber cloth core is placed in a vacuum drying oven for drying, so that the prepreg is obtained.

In the invention, the dip-coating time is preferably 30-90 s, more preferably 40-80 s, most preferably 50-70 s, and most preferably 50-60 s; the temperature of the vacuum drying is preferably 120-260 ℃, more preferably 150-250 ℃, and most preferably 180-200 ℃; the time for vacuum drying is preferably 20-40 min, and more preferably 30-35 min.

The invention also provides a copper-clad plate which comprises a copper foil and a prepreg compounded on the surface of the copper foil, wherein the prepreg is preferably the prepreg.

The invention also provides a preparation method of the copper-clad plate, which comprises the following steps:

The number of the semi-cured sheets in the invention is not particularly limited, and can be selected according to actual needs. The invention is to remove the air bubbles in the fiber and the resin, to make the fiber and the resin fully contact, and to perform vacuum-pumping treatment.

In the invention, the hot pressing temperature is 120-300 ℃, and more preferably 150-250 ℃; the hot pressing time is 2-8 h, more preferably 3-7 h, and most preferably 5-6 h; the hot pressing pressure is 1-50 MPa, more preferably 5-40 MPa, and most preferably 10-30 MPa.

In order to further illustrate the present invention, the following describes in detail a high frequency cured sheet, a method for preparing the same, a copper-clad plate and a method for preparing the same, which are provided by the present invention, with reference to the following examples, but the present invention should not be construed as being limited to the scope of the present invention.

In the following examples, the thermal expansion coefficient test adopts GB/T16535-; the thermal degradation performance test adopts GB/T11998-; the stripping conversion point test and the thermal decomposition temperature adopt GB/T27761-2011 test standards; the test of the peel strength adopts the test standard of GB/T2791-; thermal shock and tin immersion adopt GB/T15727-1995 testing standard; the tensile strength test adopts ISO7500-1 test standard; the dielectric constant and dielectric loss factor test adopts GB/T1693-2007 test standard.

Example 1

Firstly, ultrasonically cleaning aramid fiber with acetone for 2 hours, then drying, treating the aramid fiber with 20 wt% phosphoric acid solution, taking out after a certain time, repeatedly cleaning with distilled water to be neutral, and drying at the temperature of 100 ℃ for 5 hours at 4 Kpa. Then, the aramid chopped fiber, aramid pulp and basalt fiber after 20 wt% phosphoric acid solution surface treatment are mixed according to the proportion of 60%: 30%: mixing 10% by weight, adding 3% by weight of polyacrylamide, defibering to uniformly disperse each fiber in water, and adding 2% by weight of polyvinyl alcohol; and then, using an automatic paper machine to make and mold, and carrying out surface high-pressure polishing treatment after vacuum drying.

Dipping the paper-making cloth in 50% solid content glue solution composed of dicyclopentadiene phenol epoxy modified cyanate ester, novolac epoxy resin, hexagonal boron nitride, crosslinking agent triallyl isocyanurate (TAIC) and xylene, dipping for 60 seconds, and drying at 180 ℃ to obtain prepreg. Wherein, 20 parts by weight of dicyclopentadiene phenol epoxy modified cyanate ester; 30 parts of phenolic epoxy resin; 6 parts of hexagonal boron nitride; 14 parts by weight of a crosslinking agent triallyl isocyanurate (TAIC); 30 parts of xylene.

And (3) flatly superposing a plurality of prepregs and copper foils, then placing the prepregs and the copper foils on a hot drying machine, and vacuumizing to remove bubbles in the fibers and the resin and enable the fibers and the resin to be in full contact. And then carrying out a copper clad laminate hot pressing process to prepare the high-performance aramid fiber/basalt fiber copper clad laminate for high frequency.

Example 2

Firstly, ultrasonically cleaning aramid fiber with acetone for 2 hours, then drying, treating the aramid fiber with 20 wt% phosphoric acid solution, taking out after a certain time, repeatedly cleaning with distilled water to be neutral, and drying at the temperature of 100 ℃ for 5 hours at 4 Kpa. Then, the aramid chopped fiber, aramid pulp and basalt fiber after 20 wt% phosphoric acid solution surface treatment are mixed according to the proportion of 60%: 20%: mixing 20% by weight, adding 5% by weight of polyacrylamide, defibering to uniformly disperse each fiber in water, and adding 5% by weight of polyvinyl alcohol; and then, using an automatic paper machine to make and mold, and carrying out surface high-pressure polishing treatment after vacuum drying.

Dipping the paper-making cloth in 50% solid content glue solution composed of dicyclopentadiene phenol epoxy modified cyanate ester, novolac epoxy resin, alumina, crosslinking agent triallyl isocyanurate (TAIC) and xylene, dipping for 60 seconds, and drying at 180 ℃ to obtain prepreg. Wherein, 20 parts by weight of dicyclopentadiene phenol epoxy modified cyanate ester; 30 parts of phenolic epoxy resin; 5 parts of hexagonal boron nitride; 10 parts by weight of a crosslinking agent triallyl isocyanurate (TAIC); 35 parts by weight of xylene.

Example 3.

Firstly, ultrasonically cleaning aramid fiber with acetone for 2 hours, then drying, treating the aramid fiber with 20 wt% phosphoric acid solution, taking out after a certain time, repeatedly cleaning with distilled water to be neutral, and drying at the temperature of 100 ℃ for 5 hours at 4 Kpa. Then, the aramid chopped fiber, aramid pulp and basalt fiber after 20 wt% phosphoric acid solution surface treatment are mixed according to the proportion of 60%: 30%: 10 percent of the mixture is mixed, 5 percent of polyacrylamide is added, and the mixture is defibered to ensure that all fibers are uniformly dispersed in water, and 5 percent of polyvinyl alcohol is added; and then, using an automatic paper machine to make and mold, and carrying out surface high-pressure polishing treatment after vacuum drying.

Dipping the paper-making cloth in 50% solid content glue solution composed of dicyclopentadiene phenol epoxy modified cyanate ester, novolac epoxy resin, spherical aluminum nitride oxide, crosslinking agent triallyl isocyanurate (TAIC) and xylene, dipping for 60 seconds, and drying at 180 ℃ to obtain prepreg. Wherein, 20 parts by weight of dicyclopentadiene phenol epoxy modified cyanate ester; 30 parts of phenolic epoxy resin; 5 parts of hexagonal boron nitride; 10 parts by weight of a crosslinking agent triallyl isocyanurate (TAIC); 35 parts by weight of xylene.

Example 4

Firstly, ultrasonically cleaning aramid fiber with acetone for 2 hours, then drying, treating the aramid fiber with 20 wt% phosphoric acid solution, taking out after a certain time, repeatedly cleaning with distilled water to be neutral, and drying at the temperature of 100 ℃ for 5 hours at 4 Kpa. Then, the aramid chopped fiber, aramid pulp and basalt fiber after 20 wt% phosphoric acid solution surface treatment are mixed according to the proportion of 50%: 30%: mixing 20% by weight, adding polyacrylamide (5%), defibering to uniformly disperse each fiber in water, and adding polyethylene glycol (5%) by weight; and then, using an automatic paper machine to make and mold, and carrying out surface high-pressure polishing treatment after vacuum drying.

Dipping the paper-making cloth in 50% solid content glue solution composed of dicyclopentadiene phenol epoxy modified cyanate ester, novolac epoxy resin, hexagonal boron nitride, crosslinking agent triallyl isocyanurate (TAIC) and xylene, dipping for 90 seconds, and drying at 200 ℃ to obtain prepreg. 25 parts of dicyclopentadiene phenol epoxy modified cyanate ester; 30 parts of phenolic epoxy resin; 5 parts of hexagonal boron nitride; 5 parts by weight of a crosslinking agent triallyl isocyanurate (TAIC); 35 parts by weight of xylene.

Example 5

Firstly, ultrasonically cleaning aramid fiber with acetone for 2 hours, then drying, treating the aramid fiber with 20 wt% phosphoric acid solution, taking out after a certain time, repeatedly cleaning with distilled water to be neutral, and drying at the temperature of 100 ℃ for 5 hours at 4 Kpa. Then, the aramid chopped fiber, aramid pulp and basalt fiber after 20 wt% phosphoric acid solution surface treatment are mixed according to the proportion of 50%: 30%: mixing 20% by weight, adding polyacrylamide (3% by weight), defibering to uniformly disperse each fiber in water, and adding polyvinyl alcohol (5%) by weight; and then, using an automatic paper machine to make and mold, and carrying out surface high-pressure polishing treatment after vacuum drying.

Dipping the paper-making cloth in 50% solid content glue solution composed of dicyclopentadiene phenol epoxy modified cyanate ester, novolac epoxy resin, hexagonal boron nitride, crosslinking agent triallyl isocyanurate (TAIC) and xylene, dipping for 90 seconds, and drying at 200 ℃ to obtain prepreg. Wherein, 20 parts by weight of dicyclopentadiene phenol epoxy modified cyanate ester; 35 parts of phenolic epoxy resin; 5 parts of hexagonal boron nitride; 5 parts by weight of a crosslinking agent triallyl isocyanurate (TAIC); 35 parts by weight of xylene.

Example 6

Firstly, ultrasonically cleaning aramid fiber with acetone for 2 hours, then drying, treating the aramid fiber with 20 wt% phosphoric acid solution, taking out after a certain time, repeatedly cleaning with distilled water to be neutral, and drying at the temperature of 100 ℃ for 5 hours at 4 Kpa. Then, the aramid chopped fiber, aramid pulp and basalt fiber after 20 wt% phosphoric acid solution surface treatment are mixed according to the proportion of 40%: 40%: mixing 20% by weight, adding 5% by weight of polyacrylamide, defibering to uniformly disperse each fiber in water, and adding 5% by weight of polyvinyl alcohol; and then, using an automatic paper machine to make and mold, and carrying out surface high-pressure polishing treatment after vacuum drying.

Dipping the paper-making cloth in 50% solid content glue solution composed of dicyclopentadiene phenol epoxy modified cyanate ester, novolac epoxy resin, boron aluminate whisker, crosslinking agent triallyl isocyanurate (TAIC) and xylene, dipping for 90 seconds, and drying at 240 ℃ to form a prepreg. Wherein, 20 parts by weight of dicyclopentadiene phenol epoxy modified cyanate ester; 30 parts of phenolic epoxy resin; 10 parts of hexagonal boron nitride; 10 parts by weight of a crosslinking agent triallyl isocyanurate (TAIC); 30 parts of xylene.

Example 7

Firstly, ultrasonically cleaning aramid fiber with acetone for 2 hours, then drying, treating the aramid fiber with 20 wt% phosphoric acid solution, taking out after a certain time, repeatedly cleaning with distilled water to be neutral, and drying at the temperature of 100 ℃ for 5 hours at 4 Kpa. Then, the aramid chopped fiber, aramid pulp and basalt fiber after 20 wt% phosphoric acid solution surface treatment are mixed according to the proportion of 60%: 30%: mixing 10% by weight, adding 5% by weight of polyacrylamide, defibering to uniformly disperse each fiber in water, and adding 5% by weight of polyethylene glycol; and then, using an automatic paper machine to make and mold, and carrying out surface high-pressure polishing treatment after vacuum drying.

Dipping the paper-making cloth in 50% solid content glue solution composed of dicyclopentadiene phenol epoxy modified cyanate ester, novolac epoxy resin, boron aluminate whisker, crosslinking agent triallyl isocyanurate (TAIC) and xylene, dipping for 90 seconds, and drying at 240 ℃ to form a prepreg. Wherein, 30 parts by weight of dicyclopentadiene phenol epoxy modified cyanate ester; 30 parts of phenolic epoxy resin; 5 parts of hexagonal boron nitride; 5 parts by weight of a crosslinking agent triallyl isocyanurate (TAIC); 30 parts of xylene.

The invention adopts the following method to perform performance characterization on the prepreg and the copper-clad plate in the embodiment:

the surface morphology of the aramid fiber/basalt fiber in example 6 is characterized and analyzed (SEM) by the invention, and the result is shown in figures 1-2, and figure 1 is an SEM image (500 times magnified) of the mixture of the aramid chopped fiber, the aramid pulp and the basalt fiber pretreated in example 6 of the invention, and the mixture is processed and molded by papermaking

FIG. 2 is an SEM image (magnified 1000 times) of a mixture of the pretreated aramid chopped fibers, aramid pulp and basalt fibers, and then processed and formed by papermaking in example 6 of the invention, wherein the diameter of the mixture is 2-5 um.

Fig. 3 is an SEM image of the pretreated aramid chopped fiber, aramid pulp, and basalt fiber mixed post-treatment coating resin forming a coating in example 6 of the present invention, wherein the filler particle size is 1 to 30 um.

The performance parameters of the copper-clad plates in examples 1 to 7 are shown in Table 1,

table 1 performance parameters of copper clad laminate in embodiments 1 to 7 of the present invention

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The prepreg for high frequency comprises a fiber cloth core and a resin coating which is dipped and coated on the surface of the fiber cloth core;

2. The prepreg for high frequency according to claim 1, wherein the fiber cloth core is prepared by the following steps:

3. The prepreg for high frequency according to claim 1, wherein the dicyclopentadiene phenol epoxy-modified cyanate ester is prepared by the following steps:

4. The prepreg according to claim 1, wherein the thermally conductive powder is one or more of hexagonal boron nitride, alumina, spheroidized aluminum nitride and boron aluminate whiskers.

5. The prepreg according to claim 4, wherein the thermally conductive powder is added to the resin liquid after ball milling, drying and silane surface treatment in this order.

6. The prepreg according to claim 1, wherein the crosslinking agent is one or more selected from triallyl isocyanurate, dicumyl peroxide and trimethylolpropane triacrylate.

7. The method for producing a prepreg for high frequency signals as set forth in any one of claims 1 to 6, comprising the steps of:

8. A copper-clad plate comprises a copper foil and a prepreg compounded on the surface of the copper foil;

the prepreg is the prepreg for high frequency according to any one of claims 1 to 6.

9. The preparation method of the copper-clad plate according to claim 8, comprising the following steps:

10. The preparation method of claim 9, wherein the hot pressing temperature is 120-300 ℃, the hot pressing time is 2-8 h, and the hot pressing pressure is 1-50 MPa.