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CN-121975267-A - Preparation process of corrosion-resistant flame-retardant material for high-frequency copper-clad plate

CN121975267ACN 121975267 ACN121975267 ACN 121975267ACN-121975267-A

Abstract

The invention discloses a preparation method of a corrosion-resistant flame-retardant material for a high-frequency copper-clad plate, and belongs to the technical field of electronic circuit substrates. The method comprises the following steps of mixing hydroxylated hexagonal boron nitride nanosheets, aminated graphene oxide powder and nano silicon dioxide, carrying out dopamine polymerization cladding and treatment by mixing gamma-glycidoxypropyl trimethoxy silane and perfluorodecyl trimethoxy silane, obtaining a surface poly dopamine/phosphorus/fluorosilane functionalized composite filler, shearing bisphenol A epoxy resin and composite filler, phosphorus-nitrogen flame retardant and hydroxypropyl modified cellulose nanofiber at a high speed, grinding and dispersing, adding diamino diphenyl sulfone curing agent and imidazole accelerator, carrying out vacuum defoaming, carrying out silane dipping pretreatment on glass fiber cloth, preparing prepreg, symmetrically stacking a plurality of layers of prepreg and copper foil, and carrying out vacuum subsection hot pressing and curing. The material has excellent performance and is suitable for a 5G high-frequency communication substrate.

Inventors

  • ZHONG YINGXIONG
  • WEI ZHONGHUI
  • LIU MINGHUI

Assignees

  • 广东盈华电子材料有限公司

Dates

Publication Date
20260505
Application Date
20260130

Claims (8)

  1. 1. The preparation method of the corrosion-resistant flame-retardant material for the high-frequency copper-clad plate is characterized by comprising the following steps of (1) uniformly mixing (0.4-1.4) hexagonal boron nitride nanosheets subjected to hydroxylation, graphene oxide powder subjected to amination and nano silicon dioxide according to a mass ratio of 1 (0.6-1.8), adding a Tris buffer solution, adding dopamine hydrochloride according to 8-25% of the total mass of the composite filler, stirring and polymerizing for 12-36 hours at 20-40 ℃, centrifuging, washing and drying to obtain polydopamine coated composite powder; adding a solvent into the polydopamine coated composite powder, adding 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide according to 20-60% of the mass of the polydopamine coated composite powder, reacting for 4-12 h at 70-100 ℃ to obtain phosphorus grafted composite powder, then adding 100 parts of gamma-glycidoxypropyl trimethoxysilane, 1H, 2H-perfluorodecyl trimethoxysilane and absolute ethyl alcohol into a reaction kettle according to the mass ratio of 100:3-100:8:5, mixing the gamma-glycidoxypropyl trimethoxysilane, 1H, 2H-perfluorodecyl trimethoxysilane and absolute ethyl alcohol, adjusting the pH value to 3.5-5.5, hydrolyzing for 30-70 min to obtain a mixed silane solution, adding the phosphorus grafted composite powder into the mixed silane solution, performing ultrasonic dispersion for 45-120 min, then performing reduced pressure drying for 3-8 h at 60-90 ℃ to obtain a composite filler of surface polydopamine/phosphorus/fluorosilane functionalized hexagonal boron nitride/graphene oxide/nano silicon dioxide, adding 100 parts of bisphenol A type liquid epoxy resin into the reaction kettle, stirring the obtained by adding the composite filler into the reaction kettle at the temperature of 1-85 ℃ for 1-40-100 parts by stirring, performing high-speed flame retardant fiber shearing for 1-100 parts by weight of the obtained composite fiber (1-100 parts by stirring step, performing high-step of stirring for 1-40-100 parts by 1-100 parts by weight of the flame retardant fiber, grinding for 20-60 min to obtain a premix with volume average particle diameter smaller than 3 microns, adding a curing agent and an accelerator, adding 4,4' -diaminodiphenyl sulfone or a mixture of the 4,4' -diaminodiphenyl sulfone and 3,3' -diaminodiphenyl sulfone into the premix in the step (2) at 35-65 ℃, according to the epoxy equivalent of 0.85-1.15 equivalent, simultaneously adding 0.2-1.5 weight parts of 2-ethyl-4-methylimidazole, carrying out vacuum defoaming for 15-40 min, controlling the viscosity to be 800-2800mPa.s to obtain a resin system, preparing a glass fiber reinforced prepreg, soaking electronic grade glass fiber cloth pretreated by a silane coupling agent in the resin system in the step (3), controlling the content of the resin system to be 38-52% of the total mass of the electronic grade glass fiber cloth, carrying out sectional drying for 4-12 min at 75-115 ℃ and controlling the solidifying degree to be 15-35%, and carrying out lamination preforming, namely laminating a plurality of layers of copper foil and electrolytic symmetrical alternate lamination, wherein the outer layer is copper foil, the total thickness is 0.5-1.8 mm, and carrying out hot press curing in a vacuum hot press to obtain the prepreg after hot-press curing.
  2. 2. The preparation method of the corrosion-resistant flame-retardant material for the high-frequency copper-clad plate, which is characterized by comprising the steps of (1) adjusting the concentration of Tris buffer solution to 10-50 mmol/L, adjusting the pH to 8.0-9.0 through hydrochloric acid or sodium hydroxide, stirring and polymerizing the mixture in oxygen atmosphere or air for 18-30 hours after adding dopamine hydrochloride, controlling the thickness of a polydopamine coating layer to 8-25 nanometers, carrying out the grafting reaction of 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide in N, N-dimethylformamide or dioxane solvent, wherein the phosphorus grafting amount after the reaction is 5-15% of the mass of composite powder, wherein the parameters of stirring and polymerization in the step (1) are 200rpm, the parameters of centrifugal washing and drying in the step (1) are 12000rpm for 20min, drying after pure water washing, 60 ℃ and 0.1MPa for 8 hours, and the parameters of ultrasonic dispersion in the step (1) are 300W in power and 40kHz.
  3. 3. The preparation method of the corrosion-resistant flame-retardant material for the high-frequency copper-clad plate is characterized in that in the step (1), the thickness of a hexagonal boron nitride nanosheet after hydroxylation treatment is 10-150 nanometers, the transverse dimension is 1-10 micrometers, the dielectric constant is 2.8-4.2 at 1MHz, the oxygen content of the graphene oxide after amination treatment is 6-15 wt%, the C/O atomic ratio is 4-12, the number of sheet layers is 3-12, the specific surface area is 200-700 m 2 /g, the average particle size of nano silicon dioxide is 15-60 nanometers, and the specific surface area is 180-350 m 2 /g.
  4. 4. The preparation method of the corrosion-resistant flame-retardant material for the high-frequency copper-clad plate, which is characterized in that in the step (2), phosphorus-nitrogen flame retardant is compounded by bis (cyanamide) diphenyl phosphite and pentaerythritol bis (diphenyl phosphate) according to a mass ratio of 40:60, and melamine cyanurate is further added in an amount of 1-8 parts by weight; the high-speed shearing stirring parameters in the step (2) are 6000rpm, 85 ℃ and 20m/s shearing rate, the grinding parameters in the step (2) are 800rpm, the ball-to-ball ratio is 20:1, the balls are zirconia balls with the diameter of 0.5mm, the time is 60min, the preparation method of the hydroxypropyl modified cellulose nanofiber in the step (2) is that 5g of microcrystalline cellulose is dispersed in 495mL of deionized water, 0.5g of 2, 6-tetramethylpiperidine-1-oxygen free radical and 2.26g of sodium hypochlorite are added, 500W ultrasonic is carried out for 2h, 1g of sodium hydroxide aqueous solution which is dissolved in 7wt percent is taken after freeze drying, precooling is carried out for 2h at-12 ℃, stirring and dissolving are carried out, 4g of propylene oxide is added for reaction for 24h at 80 ℃, neutralization with acetic acid is carried out for 3 days after dialysis for 12kDa, 80 ℃ drying is carried out, then the microcrystalline cellulose is dissolved to 15wt%, the voltage is 25kV, the flow rate is 1mL/h, and the diameter of 20cm and 40 ℃ is dried, thus obtaining the 100nm fiber.
  5. 5. The method for preparing the corrosion-resistant flame-retardant material for the high-frequency copper-clad plate, which is characterized in that in the step (3), the curing agent is a mixture of 4,4 '-diaminodiphenyl sulfone and 3,3' -diaminodiphenyl sulfone in a mass ratio of (65-85) (15-35), bisphenol A diglycidyl ether is added as a reactive diluent in an amount of 2-8 parts by weight, and the viscosity at 80 ℃ is controlled to be 400-480 mPas.
  6. 6. The preparation method of the corrosion-resistant flame-retardant material for the high-frequency copper-clad plate is characterized in that glass fiber cloth is plain weave fabric in the step (4), the diameter of monofilaments is 5-12 microns, the warp and weft density is 10-25 pieces/cm, the coating thickness difference of two sides of resin in the impregnation process is not more than 8 microns, the resin is dried in sections, the temperature is kept at 65-85 ℃ for 2-6 min in the first section and at 95-115 ℃ for 3-9 min in the second section, the electronic grade glass fiber cloth pretreated by a silane coupling agent in the step (4) is prepared by immersing the electronic grade glass fiber cloth in a 0.5mol/L sodium hydroxide solution for 30min, washing and neutrality, drying, and then immersing the electronic grade glass fiber cloth in a 2vol% gamma-glycidoxypropyl trimethoxysilane solution with the mass of 10-20 times, and drying for 2h at 150 ℃.
  7. 7. The method for preparing the corrosion-resistant flame-retardant material for the high-frequency copper-clad plate, which is characterized in that in the step (5), a copper foil/prepreg multilayer/copper foil symmetrical structure is laminated, the thickness of a single-layer prepreg is 60-200 microns, preheating is carried out for 5-20 min at the temperature of 0.3-0.6 megapascal and at the temperature of 90-130 ℃ before lamination, bubbles are eliminated, and the resin primary flow curing degree is 12-28%.
  8. 8. The method for preparing the corrosion-resistant flame-retardant material for the high-frequency copper-clad plate, which is characterized in that a segmented hot-pressing procedure is adopted in the step (6), wherein the temperature is firstly increased to 110-140 ℃ under the condition that the vacuum degree is not higher than-0.098 megapascals, the pressure is kept at 1.2-2.8 megapascals for 15-45 min, then the temperature is increased to 170-220 ℃, the pressure is kept at 2.5-5.5 megapascals for 80-160 min, and then the temperature is cooled to 60-80 ℃ at 8-25 ℃ per min for pressure relief and demoulding.

Description

Preparation process of corrosion-resistant flame-retardant material for high-frequency copper-clad plate Technical Field The invention belongs to the technical field of electronic circuit base materials, and particularly relates to a preparation process of a corrosion-resistant flame-retardant material for a high-frequency copper-clad plate. Background The copper-clad plate is used as a core carrier of the PCB, and the dielectric constant (Dk) and the dielectric dissipation factor (Df) of the copper-clad plate directly influence the signal integrity, the transmission delay and the power consumption. In high frequency environments, signal loss is mainly due to dielectric loss and conductor loss, where dielectric loss is proportional to Df. The Dk of the traditional FR-4 epoxy resin-based copper-clad plate is generally 4.0-4.5, df is about 0.02, and the requirement of low attenuation transmission of high-frequency signals cannot be met, so that signal distortion and heat consumption are increased, and the performance improvement of applications such as a 5G base station, a radio frequency module, an antenna array, an AI server and the like is severely restricted. To accommodate the high frequency and high speed requirements, a variety of specialized resin systems have been developed. Mainly comprises Polytetrafluoroethylene (PTFE) substrate, hydrocarbon resin (Hydrocarbon), polyphenylene oxide (PPO/PPE) modified resin, cyanate ester resin, liquid Crystal Polymer (LCP) substrate, etc. PTFE substrates have extremely low Dk (2.1-2.8) and Df (about 0.001), and have low signal transmission loss, but have problems of high processing temperature (> 300 ℃), poor adhesion to copper foil, poor dimensional stability due to large Coefficient of Thermal Expansion (CTE), high cost and the like, and limit large-scale application thereof. The PPO/PPE resin Dk is about 3.0-3.5, df is about 0.005, and the modified PPO/PPE resin has better heat resistance, but has higher thermal expansion coefficient, is easy to cause the warping of the plate, and has complex modification process. Cyanate resin has excellent dielectric property and strong heat resistance, but has high curing temperature, large brittleness and higher moisture absorption rate, and is easy to cause dielectric property attenuation in a humid environment. The LCP substrate Dk is extremely low and Df is minimum, but the cost is high, the processing difficulty is high, and the LCP substrate is only suitable for the field of high-end flexible boards. In addition, hydrocarbon resins such as polyphenylene sulfide (PPS) or modified polyolefin systems have progressed in terms of low loss, but have insufficient flame retardancy and corrosion resistance, and it is difficult to fully satisfy the requirements of multi-layer high-frequency boards. The flame retardant property is another key index of the copper-clad plate. The safety standard of the electronic product meets the V-0 grade flame retardance of the UL-94 standard. Traditional halogen flame retardants (such as brominated flame retardants) have high flame retardant efficiency, but release toxic gases and corrosive substances during combustion, which are limited by environmental regulations such as RoHS, REACH and the like. Halogen-free flame retardance is the mainstream direction of industry, and phosphorus (such as DOPO and derivatives thereof), nitrogen (such as melamine cyanurate) or phosphorus-nitrogen synergistic flame retardants are mainly adopted. These halogen-free flame retardants are environmentally friendly but have lower flame retardant efficiency and require higher amounts of additives (typically >20 wt%), which can significantly increase the polarity of the resin system, leading to increased Dk and Df, increased water absorption, and reduced heat resistance and mechanical properties. For example, a phosphorus flame retardant can promote char formation, but a high addition amount tends to cause phase separation, affecting the uniformity of the sheet. In the prior art, if phosphorus modified epoxy or a compound flame retardant system is adopted, the V-0 level can be realized, but the low dielectric loss characteristic is usually sacrificed, and the compatibility in high-frequency application is difficult. Corrosion resistance and wet heat resistance are also critical. High frequency PCBs are often used in complex environments such as base stations exposed to marine climates, residual acidic flux from soldering processes, or AI data centers in high humidity and high temperature conditions. The traditional epoxy resin has strong hydrophilicity, the water absorption rate is generally more than 0.3-0.5%, dk rises and Df increases dramatically after water absorption, and signals are unstable. Meanwhile, in an acidic environment (such as 10wt% HCl), the resin matrix is easy to hydrolyze and the filler interface corrodes, resulting in weight loss and surface damage. Although the existing fluorinated resin has str