CN111825955B

CN111825955B - Prepreg for high frequency, preparation method thereof and copper-clad plate and preparation method thereof

Info

Publication number: CN111825955B
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: 2023-07-21
Anticipated expiration: 2040-07-23
Also published as: CN111825955A

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 fiber and aramid fiber are manufactured into fiber cloth together, and high-pressure treatment is carried out under the action of high temperature and high pressure; (2) Dip-coating the paper-making cloth in a glue solution with 50% of solid content, wherein the glue solution consists of dicyclopentadiene phenol epoxy modified cyanate, phenolic epoxy resin, heat-conducting powder, triallyl isocyanurate (TAIC) as a crosslinking agent and xylene, and drying the paper-making cloth at 120-260 ℃ after dip-coating for 30-90 seconds; and (3) overlapping the prepreg and the copper foil, and performing hot press molding. Thus, the high-performance aramid fiber/basalt fiber-based copper-clad plate which meets the requirements of low dielectric constant, low dielectric loss tangent, good heat resistance, high thermal decomposition temperature, thermal shock resistance, good tensile strength, good peel strength, excellent interfacial shear strength and excellent dimensional stability for high-frequency use is prepared.

Description

Prepreg for high frequency, preparation method thereof and copper-clad plate and preparation method thereof

Technical Field

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

Background

The current trend of global informatization technology is increasingly strong, digitization, informatization and networking go deep into various industries and fields, and the cross development of technologies in various fields such as new energy technology, new material technology, biotechnology and the like is causing a new technological revolution and industrial revolution in the world. At the same time, the key to restrict the development of informatization technology is the information carrying, transmitting and processing capabilities of the electronic devices. The requirements of higher performance are put forward on a Printed Circuit Board (PCB) in basic electronic equipment, and the requirements of flame retardance, insulativity and heat resistance of the PCB are more severe while the development of electronic technology is satisfied.

The printed circuit board on the electronic equipment which is widely used in China is a traditional copper-clad plate, and the basic process of the traditional copper-clad plate such as epoxy resin/glass cloth is mature, and when the traditional copper-clad plate is used as a base material of a high-frequency and high-performance printed circuit board, the traditional copper-clad plate has the problems of low moisture resistance, poor dielectric property, high thermal expansion rate and the like. In order to meet the application of aerospace electronic equipment, military defense and military weapon communication equipment, it is urgent to develop a high-performance copper-clad plate which meets the requirements of low dielectric constant, low dielectric loss tangent, good heat resistance, high glass transition temperature, good tensile strength, excellent interfacial shear strength and excellent dimensional stability for high-frequency use.

Disclosure of Invention

The invention aims to provide a high-frequency curing sheet, a preparation method thereof, a copper-clad plate and a preparation method thereof, wherein the copper-clad plate prepared from the curing sheet has the advantages of low dielectric constant (2.8-3.6), low dielectric loss tangent (0.0059-0.0071), good heat resistance, high thermal decomposition temperature (320.62-340.61 ℃) and thermal shock resistance, good tensile strength and peeling strength (2.0-2.7N/mm), excellent interfacial shear strength and excellent dimensional stability.

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

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

dicyclopentadiene phenol epoxy modified cyanate: 15-30 parts by weight of phenolic 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: 30-50 parts by weight.

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

aramid pulp, basalt fiber and 10 to 30 weight percent of phosphoric acid treated aramid fiber are mixed with water according to the weight ratio of 1: mixing the components in the proportion of (1-5), adding a dispersing agent, uniformly dispersing, adding a water-based adhesive, carrying out papermaking forming, and carrying out vacuum drying to obtain a fiber cloth sheet core;

the weight ratio of the 10-30wt% of the phosphoric acid treated aramid fiber, 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 is prepared according to the following steps:

and (3) melting cyanate resin, adding dicyclopentadiene phenol epoxy resin, reacting for 60-90 min at 120-180 ℃, cooling to 80-100 ℃, adding dibutyl tin dilaurate, and continuing to react to obtain dicyclopentadiene phenol epoxy modified cyanate.

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

Preferably, the heat conducting powder is sequentially subjected to ball milling, drying and silane surface treatment and then added into the resin glue solution.

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

The method for preparing the prepreg for high frequency as described above, comprising the steps of:

the fiber cloth piece core is dip-coated in the resin glue solution for 30-90 s and then dried at 120-260 ℃ to obtain the high-frequency curing piece.

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 high-frequency prepreg.

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

and (3) superposing at least one prepreg and the copper foil, and carrying out hot pressing after vacuumizing treatment to obtain the copper-clad plate.

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

The invention provides a prepreg for high frequency, which comprises a fiber cloth piece core and a resin coating which is dip-coated on the surface of the fiber cloth piece core; the fiber cloth piece core is made of basalt fibers and aramid fibers, the resin coating is obtained by drying resin glue liquid, and the resin glue liquid comprises the following components in parts by weight: dicyclopentadiene phenol epoxy modified cyanate: 15-30 parts by weight of phenolic 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: 30-50 parts by weight. According to the invention, the aramid fiber/basalt fiber paper-making cloth is prepared by utilizing excellent heat resistance, flame retardance, insulativity and mechanical property of the aramid fiber and basalt fiber through the complex phase synergistic effect. The dicyclopentadiene phenol epoxy modified cyanate ester and phenolic epoxy resin composite resin with low dielectric constant, low dielectric loss, low water absorption and good flame retardance are used as a glue solution matrix to prepare a prepreg, and the aramid fiber/basalt fiber prepreg for high frequency and the high-performance copper-clad plate are prepared 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 that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.

FIG. 1 SEM image (500 times magnification) of the pre-treated aramid chopped fibers, aramid pulp and basalt fibers of the invention of example 6 after mixing and post-treatment and papermaking molding;

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

fig. 3 is an SEM image of the pre-treated aramid chopped fibers, aramid pulp, and basalt fibers of example 6 of the present invention after mixing and treating the coating resin to form a coating.

Detailed Description

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

In the invention, the fiber cloth piece core is made of basalt fiber and aramid fiber, and the specific preparation process is as follows:

the aramid fiber is first surface treated with phosphoric acid.

The method comprises the steps of firstly ultrasonically cleaning the aramid fiber with acetone for 2-3 hours, then drying, treating with phosphoric acid solution, then repeatedly cleaning with distilled water to the center, and drying to obtain the aramid fiber treated with phosphoric acid.

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

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

(1) 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 better compatibility is shown between the fiber and the resin matrix (the combination between the fiber and the resin matrix is mainly the adsorption effect of the polar functional groups on the surface of the fiber and the resin matrix).

(2) The wettability between the aramid fiber and the resin after the phosphoric acid treatment is improved.

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

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

And then, manufacturing and shaping the aramid fiber, basalt fiber and aramid pulp subjected to phosphoric acid treatment.

Aramid pulp, basalt fiber and 10 to 30 weight percent of phosphoric acid treated aramid fiber are mixed with water according to the weight ratio of 1: mixing the components in the proportion of (1-5), adding a dispersing agent, uniformly dispersing, adding a water-based adhesive, and finally forming the mixed solution by papermaking and vacuum drying to obtain the fiber cloth piece core.

Preferably, the invention firstly uses aramid pulp, basalt fiber and 10-30wt% of phosphoric acid treated aramid fiber and water according to the weight ratio of 1: mixing the components in the proportion of (1-5), adding a dispersing agent for fluffing 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, and carrying out high-pressure surface polishing treatment after vacuum drying to obtain the fiber cloth sheet core.

In the invention, the aramid pulp is obtained by carrying out surface fibrillation treatment on the aramid fiber, and the unique surface structure of the aramid pulp greatly improves the grip of the mixture, so the aramid pulp is very suitable for being used as a reinforcing fiber in friction and sealing products. The aramid pulp is softer and the surface is divided into filaments, so that the aramid fibers are more tightly crosslinked and combined with the resin matrix, and the overall performance is improved. The mass fraction of the aramid pulp in the mixed solution is preferably 5 to 50%, more preferably 10 to 40%, more preferably 15 to 35%, and most preferably 20 to 30%.

The basalt fiber is preferably basalt fiber roving, which is formed by combining a plurality of strands of parallel filaments or a single strand of parallel filaments in a non-twisting state, and is synergistic with aramid fiber to toughen multiphase fiber. The mass fraction of the basalt fiber in the mixed solution is preferably 5-20%, more preferably 10-15%.

In the present invention, the mass fraction of the aramid fiber after the phosphoric acid treatment in the mixed solution is preferably 10 to 80%, more preferably 20 to 70%, most preferably 30 to 60%, and most preferably 40 to 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 to 80), preferably (10 to 40): (10-15): (20-70), specifically, in the embodiment of the present invention, may be 60:30: 10. 40:40: 20. 50:30:20 or 60:20:20.

in the invention, the dispersing agent 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 to 5%, more preferably 2 to 4%, and most preferably 3%. After the dispersant is added, the solution is fluffed by an LW standard fluffer, and the fluffing rotating speed is preferably 5000-50000 rpm.

In the invention, the aqueous adhesive 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 to 5%, more preferably 2 to 4%, and most preferably 3%.

In the invention, the temperature of vacuum drying after paper making and molding is preferably 120-260 ℃, more preferably 150-200 ℃; the time of the vacuum drying is preferably 20 to 40min, more preferably 30 to 35min; the vacuum degree of the vacuum drying is excellentSelected as 10 ⁵ ～10 ² Pa, more preferably 10 ⁴ ～10 ³ Pa。

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

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

dicyclopentadiene phenol epoxy modified cyanate: 15 to 30 parts by weight, preferably 20 to 25 parts by weight, and specifically, in an embodiment of the present invention, may be 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, and specifically, 30 parts by weight, 35 parts by weight, 45 parts by weight may be used in the embodiment of the present invention;

and (3) heat conducting powder: 5 to 10 parts by weight, preferably 6 to 9 parts by weight, more preferably 7 to 8 parts by weight, and specifically, in the embodiment of the present invention, 6 parts by weight, 5 parts by weight, 8 parts by weight, 10 parts by weight;

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

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

The solid content of the resin dope in the present invention is preferably 40 to 70%, more preferably 50 to 60%.

In the invention, the dicyclopentadiene phenol epoxy modified cyanate is prepared according to the following steps:

and (3) melting cyanate resin, adding dicyclopentadiene phenol epoxy resin, stirring at 120-180 ℃ for reaction 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.

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

in the present invention, the melting temperature of the cyanate resin is preferably 140 to 160 ℃, more preferably 150 ℃; the temperature of the reaction is preferably 120 to 180 ℃, more preferably 130 to 170 ℃, most preferably 140 to 160 ℃, and in particular, in an embodiment of the present invention, may be 150 ℃; the reaction time is preferably 60 to 90min, more preferably 70 to 80min, and most preferably 75min; the temperature of the cooling is preferably 80-100 ℃, more preferably 90 ℃, and the stirring reaction is continued for 15-20 min after the dibutyl tin dilaurate is added.

The resin matrix of the resin glue solution in the invention is dicyclopentadiene phenol epoxy modified cyanate and phenolic 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 excellent heat resistance and chemical stability after curing. The dicyclopentadiene phenol epoxy resin modified by polyurethane can further reduce the thermal expansion coefficient, the water absorption and the chemical stability of the resin cured product. Meanwhile, the compressive strength and the impact resistance of the original dicyclopentadiene phenol epoxy resin are improved, and the toughness and the wear resistance are improved.

The phenolic resin has low cost, simple production and processing, high strength of the cured product, excellent high temperature resistance, corrosion resistance and flame resistance, and high heat distortion temperature.

In the invention, the heat conducting powder is preferably one or more of hexagonal boron nitride, aluminum oxide, spherical aluminum nitride and boron aluminate whisker; the invention preferably uses the silane coupling agent to modify the heat conduction powder, and then adds the modified heat conduction powder into the resin glue solution for impregnation.

The specific modification method comprises the following steps:

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

The heat conducting powder is ball milled. Evenly dispersed in the matrix material, and is beneficial to the improvement of the heat conductivity coefficient. 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, is prepared into composite material with thermosetting resin, and the inorganic material and the polymer are connected in two interfaces to obtain optimal wetting value and dispersivity.

In the present 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 the high frequency, which comprises the following steps:

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

The invention preferably places the fiber cloth sheet core in the resin glue solution smoothly, and the single side is gradually touched with glue until the fiber cloth sheet core is completely dip-coated in the glue solution for about 30 to 90 seconds, then takes out, stands for airing, and then places the fiber cloth sheet core in a vacuum drying oven for drying to obtain the prepreg.

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

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 invention has no special limit to the number of prepregs, and can be selected according to actual needs. The invention is to remove bubbles in the fiber and the resin, fully contact the fiber and the resin, and carry out vacuumizing treatment.

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

In order to further illustrate the present invention, the following examples are provided to describe the curing sheet for high frequency, the preparation method thereof, the copper-clad plate and the preparation method thereof in detail, but the present invention is not to be construed as being limited to the scope of protection.

In the following examples, the thermal expansion coefficient test was conducted using GB/T16535-2008 standard test; the thermal degradation performance test adopts GB/T11998-1989 test standard; the stripping conversion point test and the thermal decomposition temperature adopt GB/T27761-2011 test standards; the peel strength test adopts GB/T2791-1995 test standard; thermal shock and wicking adopted GB/T15727-1995 test standard; tensile strength test adopts ISO7500-1 test standard; the dielectric constant and dielectric loss factor test uses GB/T1693-2007 test standard.

Example 1

Firstly, the aramid fiber is ultrasonically cleaned by acetone for 2 hours and then dried, the aramid fiber is treated by 20wt% of phosphoric acid solution, taken out after a certain time, repeatedly cleaned by distilled water to be neutral, and dried for 5 hours at the temperature of 4Kpa and 100 ℃. Then, the aramid chopped fiber after surface treatment of 20wt% phosphoric acid solution, aramid pulp and basalt fiber are mixed according to the ratio of 60 percent: 30%: mixing 10% by weight, adding polyacrylamide with a weight ratio of 3%, fluffing to uniformly disperse all fibers in water, and adding polyvinyl alcohol with a weight ratio of 2%; and then, using an automatic paper machine to manufacture and shape, and carrying out high-pressure surface polishing treatment after vacuum drying.

Dip-coating the paper-making cloth in a glue solution with 50% of solid content, which consists of dicyclopentadiene phenol epoxy modified cyanate, phenolic epoxy resin, hexagonal boron nitride, triallyl isocyanurate (TAIC) as a crosslinking agent and xylene, dip-coating for 60 seconds, and drying at 180 ℃ to obtain the prepreg. Wherein, dicyclopentadiene phenol epoxy modified cyanate is 20 weight portions; 30 parts of phenolic epoxy resin; 6 parts by weight of hexagonal boron nitride; 14 parts by weight of triallyl isocyanurate (TAIC) as a crosslinking agent; 30 parts of dimethylbenzene.

And (3) after the prepregs and the copper foils are flatly overlapped, placing the prepregs and the copper foils on a hot drier, and carrying out vacuumizing treatment to remove bubbles in the fibers and the resin so that the fibers are fully contacted with the resin. And then carrying out a hot pressing process of the copper clad laminate to prepare the high-performance copper clad laminate of the aramid fiber/basalt fiber for high frequency.

Example 2

Firstly, the aramid fiber is ultrasonically cleaned by acetone for 2 hours and then dried, the aramid fiber is treated by 20wt% of phosphoric acid solution, taken out after a certain time, repeatedly cleaned by distilled water to be neutral, and dried for 5 hours at the temperature of 4Kpa and 100 ℃. Then, the aramid chopped fiber after surface treatment of 20wt% phosphoric acid solution, aramid pulp and basalt fiber are mixed according to the ratio of 60 percent: 20%: mixing 20% by weight of polyacrylamide and fluffing to uniformly disperse all fibers in water, and adding polyvinyl alcohol with a weight ratio of 5%; and then, using an automatic paper machine to manufacture and shape, and carrying out high-pressure surface polishing treatment after vacuum drying.

Dip-coating the paper-making cloth in a glue solution with 50% of solid content, which consists of dicyclopentadiene phenol epoxy modified cyanate, phenolic epoxy resin, aluminum oxide, triallyl isocyanurate (TAIC) as a crosslinking agent and xylene, dip-coating for 60 seconds, and drying at 180 ℃ to obtain the prepreg. Wherein, dicyclopentadiene phenol epoxy modified cyanate is 20 weight portions; 30 parts of phenolic epoxy resin; 5 parts by weight of hexagonal boron nitride; 10 parts by weight of triallyl isocyanurate (TAIC) as a crosslinking agent; and 35 parts of dimethylbenzene.

Example 3.

Firstly, the aramid fiber is ultrasonically cleaned by acetone for 2 hours and then dried, the aramid fiber is treated by 20wt% of phosphoric acid solution, taken out after a certain time, repeatedly cleaned by distilled water to be neutral, and dried for 5 hours at the temperature of 4Kpa and 100 ℃. Then, the aramid chopped fiber after surface treatment of 20wt% phosphoric acid solution, aramid pulp and basalt fiber are mixed according to the ratio of 60 percent: 30%: mixing 10% by weight, adding polyacrylamide 5% by weight, dispersing to uniformly disperse each fiber in water, and adding polyvinyl alcohol 5% by weight; and then, using an automatic paper machine to manufacture and shape, and carrying out high-pressure surface polishing treatment after vacuum drying.

Dip-coating the paper-making cloth in a glue solution with 50% of solid content, which consists of dicyclopentadiene phenol epoxy modified cyanate, phenolic epoxy resin, spherical nitrided alumina, triallyl isocyanurate (TAIC) as a crosslinking agent and xylene, and drying the paper-making cloth at 180 ℃ to obtain a prepreg after dip-coating for 60 seconds. Wherein, dicyclopentadiene phenol epoxy modified cyanate is 20 weight portions; 30 parts of phenolic epoxy resin; 5 parts by weight of hexagonal boron nitride; 10 parts by weight of triallyl isocyanurate (TAIC) as a crosslinking agent; and 35 parts of dimethylbenzene.

Example 4

Firstly, the aramid fiber is ultrasonically cleaned by acetone for 2 hours and then dried, the aramid fiber is treated by 20wt% of phosphoric acid solution, taken out after a certain time, repeatedly cleaned by distilled water to be neutral, and dried for 5 hours at the temperature of 4Kpa and 100 ℃. Then, carrying out surface treatment on the aramid chopped fiber and the basalt fiber which are subjected to surface treatment by 20wt% of phosphoric acid solution according to the proportion of 50 percent: 30%: mixing 20% by weight, adding polyacrylamide (5%), fluffing to uniformly disperse each fiber in water, and adding polyethylene glycol (5%) by weight; and then, using an automatic paper machine to manufacture and shape, and carrying out high-pressure surface polishing treatment after vacuum drying.

Dip-coating the paper-making cloth in a glue solution with 50% of solid content, which consists of dicyclopentadiene phenol epoxy modified cyanate, phenolic epoxy resin, hexagonal boron nitride, triallyl isocyanurate (TAIC) as a crosslinking agent and xylene, dip-coating for 90 seconds, and drying at 200 ℃ to obtain the prepreg. Wherein, dicyclopentadiene phenol epoxy modified cyanate is 25 weight portions; 30 parts of phenolic epoxy resin; 5 parts by weight of hexagonal boron nitride; 5 parts by weight of triallyl isocyanurate (TAIC) as a crosslinking agent; and 35 parts of dimethylbenzene.

Example 5

Firstly, the aramid fiber is ultrasonically cleaned by acetone for 2 hours and then dried, the aramid fiber is treated by 20wt% of phosphoric acid solution, taken out after a certain time, repeatedly cleaned by distilled water to be neutral, and dried for 5 hours at the temperature of 4Kpa and 100 ℃. Then, carrying out surface treatment on the aramid chopped fiber and the basalt fiber which are subjected to surface treatment by 20wt% of phosphoric acid solution according to the proportion of 50 percent: 30%: mixing 20% by weight, adding polyacrylamide (3%) by weight, dispersing to uniformly disperse each fiber in water, and adding polyvinyl alcohol (5%) by weight; and then, using an automatic paper machine to manufacture and shape, and carrying out high-pressure surface polishing treatment after vacuum drying.

Dip-coating the paper-making cloth in a glue solution with 50% of solid content, which consists of dicyclopentadiene phenol epoxy modified cyanate, phenolic epoxy resin, hexagonal boron nitride, triallyl isocyanurate (TAIC) as a crosslinking agent and xylene, dip-coating for 90 seconds, and drying at 200 ℃ to obtain the prepreg. Wherein, dicyclopentadiene phenol epoxy modified cyanate is 20 weight portions; 35 parts by weight of phenolic epoxy resin; 5 parts by weight of hexagonal boron nitride; 5 parts by weight of triallyl isocyanurate (TAIC) as a crosslinking agent; and 35 parts of dimethylbenzene.

Example 6

Firstly, the aramid fiber is ultrasonically cleaned by acetone for 2 hours and then dried, the aramid fiber is treated by 20wt% of phosphoric acid solution, taken out after a certain time, repeatedly cleaned by distilled water to be neutral, and dried for 5 hours at the temperature of 4Kpa and 100 ℃. Then, carrying out surface treatment on the aramid chopped fiber and the basalt fiber which are subjected to surface treatment by a 20wt% phosphoric acid solution according to the proportion of 40 percent: 40%: mixing 20% by weight, adding polyacrylamide (5%), fluffing to uniformly disperse each fiber in water, and adding polyvinyl alcohol (5%) by weight; and then, using an automatic paper machine to manufacture and shape, and carrying out high-pressure surface polishing treatment after vacuum drying.

Dip-coating the paper-making cloth in a glue solution with 50% of solid content, which consists of dicyclopentadiene phenol epoxy modified cyanate, phenolic epoxy resin, boron aluminate whisker, triallyl isocyanurate (TAIC) as a crosslinking agent and xylene, dip-coating for 90 seconds, and drying at 240 ℃ to obtain the prepreg. Wherein, dicyclopentadiene phenol epoxy modified cyanate is 20 weight portions; 30 parts of phenolic epoxy resin; 10 parts of hexagonal boron nitride; 10 parts by weight of triallyl isocyanurate (TAIC) as a crosslinking agent; 30 parts of dimethylbenzene.

Example 7

Firstly, the aramid fiber is ultrasonically cleaned by acetone for 2 hours and then dried, the aramid fiber is treated by 20wt% of phosphoric acid solution, taken out after a certain time, repeatedly cleaned by distilled water to be neutral, and dried for 5 hours at the temperature of 4Kpa and 100 ℃. Then, the aramid chopped fiber after surface treatment of 20wt% phosphoric acid solution, aramid pulp and basalt fiber are mixed according to the ratio of 60 percent: 30%:10% of the components are mixed according to the weight ratio, polyacrylamide (5%) is added for fluffing, so that all the fibers are uniformly dispersed in water, and polyethylene glycol is added according to the weight ratio (5%); and then, using an automatic paper machine to manufacture and shape, and carrying out high-pressure surface polishing treatment after vacuum drying.

Dip-coating the paper-making cloth in a glue solution with 50% of solid content, which consists of dicyclopentadiene phenol epoxy modified cyanate, phenolic epoxy resin, boron aluminate whisker, triallyl isocyanurate (TAIC) as a crosslinking agent and xylene, dip-coating for 90 seconds, and drying at 240 ℃ to obtain the prepreg. Wherein, dicyclopentadiene phenol epoxy modified cyanate is 30 weight portions; 30 parts of phenolic epoxy resin; 5 parts by weight of hexagonal boron nitride; 5 parts by weight of triallyl isocyanurate (TAIC) as a crosslinking agent; 30 parts of dimethylbenzene.

The performance of the prepreg and the copper-clad plate in the embodiment is characterized by adopting the following method:

the invention characterizes and analyzes the surface morphology of the aramid fiber/basalt fiber in the embodiment 6 (SEM), the results are shown in figures 1-2, and the pretreated aramid chopped fiber, aramid pulp and basalt fiber in the embodiment 6 of the invention are mixed and then processed to manufacture a formed SEM image (500 times magnification) in figure 1

FIG. 2 is an SEM image (magnified 1000 times) of the pre-treated aramid chopped fibers, aramid pulp, and basalt fibers of example 6 of the present invention, mixed, post-treated and formed with paper, wherein the diameter is 2-5 um.

Fig. 3 is an SEM image of the pretreated aramid chopped fiber, aramid pulp, and basalt fiber of example 6 of the present invention after mixing and treating the coating resin to form a coating, wherein the filler particle size is 1-30 um.

The performance parameters of the copper clad laminate in examples 1 to 7 are shown in table 1,

TABLE 1 Performance parameters of copper-clad plates in examples 1 to 7 of the present invention

The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.

Claims

1. A prepreg for high frequency comprises a fiber cloth piece core and a resin coating which is dip-coated on the surface of the fiber cloth piece core;

the fiber cloth piece core is prepared according to the following steps:

the weight ratio of the 10-30wt% of the phosphoric acid treated aramid fiber, 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);

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: 15-30 parts by weight of phenolic 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: 30-50 parts by weight;

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

2. The prepreg according to claim 1, wherein the heat conductive powder is one or more of hexagonal boron nitride, aluminum oxide, spherical aluminum nitride and boron aluminate whisker.

3. The prepreg according to claim 2, wherein the heat conductive powder is added to the resin dope after ball milling, drying and silane surface treatment in this order.

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

5. The method for preparing a prepreg for high frequency as recited in any one of claims 1 to 4, comprising the steps of:

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

the prepreg according to any one of claims 1 to 4.

7. The method for producing a copper-clad plate according to claim 6, comprising the steps of:

8. The method according to claim 7, wherein the hot pressing temperature is 120 to 300 ℃, the hot pressing time is 2 to 8 hours, and the hot pressing pressure is 1 to 50MPa.