CN-117341305-B - Para-aramid nanofiber modified polytetrafluoroethylene glass fiber cloth high-frequency copper-clad plate and preparation method thereof

CN117341305BCN 117341305 BCN117341305 BCN 117341305BCN-117341305-B

Abstract

The invention provides a para-aramid nanofiber modified polytetrafluoroethylene glass fiber cloth high-frequency copper-clad plate and a preparation method thereof, comprising the following steps of A) modifying glass fiber cloth by using a silane coupling agent to obtain surface modified glass fiber cloth; the preparation method comprises the steps of B), immersing surface-modified glass fiber cloth in aramid nanofiber-modified polytetrafluoroethylene gum dipping liquid, taking out and drying to obtain gum dipping glass fiber cloth, C), sequentially stacking the gum dipping glass fiber cloth, sequentially drying, removing impurities and sintering in a vacuum environment to obtain a prepreg, D), coating copper foil on the prepreg, and carrying out vacuum hot pressing treatment to obtain the para-aramid nanofiber-modified polytetrafluoroethylene glass fiber cloth high-frequency copper-clad plate. The para-aramid nanofiber modified polytetrafluoroethylene glass fiber cloth high-frequency copper-clad plate has excellent dielectric property, and the performances of water absorption, anti-stripping strength, ultralow loss, linear thermal expansion coefficient and the like all meet the index requirements of the copper foil-clad polytetrafluoroethylene glass fiber cloth laminated plate for a microwave circuit.

Inventors

GAO XIAOJIA
ZHUANG RUI
LI SHUANGCHANG
FAN CUILING
WEI NAN
WANG XIANLI

Assignees

黄河三角洲京博化工研究院有限公司

Dates

Publication Date: 20260508
Application Date: 20231009

Claims (6)

1. A preparation method of a para-aramid nanofiber modified polytetrafluoroethylene glass fiber cloth high-frequency copper-clad plate comprises the following steps: A) Modifying the glass fiber cloth by using a silane coupling agent to obtain surface modified glass fiber cloth, wherein the silane coupling agent is gamma-glycidol ether oxygen propyl trimethoxy silane; b) Immersing the surface-modified glass fiber cloth in an aramid nanofiber-modified polytetrafluoroethylene immersing liquid, taking out and drying to obtain an immersing glass fiber cloth; the aramid nanofiber modified polytetrafluoroethylene dipping solution is obtained by mixing polytetrafluoroethylene water dispersion emulsion and aramid nanofiber slurry, wherein the aramid nanofiber slurry is obtained by dispersing para-aramid nanofibers in water, the diameter of the para-aramid nanofibers is 10-100 nm, and the mass ratio of the water to the para-aramid nanofibers is 300 (3-10); In the aramid nanofiber modified polytetrafluoroethylene dipping solution, the mass ratio of polytetrafluoroethylene to para-aramid nanofiber is 1 (0.003-0.08); c) Sequentially stacking the gum dipping glass fiber cloth, and sequentially drying, removing impurities and sintering in a vacuum environment to obtain a prepreg; The drying temperature in the step C) is 80-100 ℃, and the drying time is 10-30 min; the impurity removal temperature is 220-240 ℃, and the impurity removal heat preservation time is 10-20 min; the sintering temperature is 330-350 ℃, and the sintering heat preservation time is 60-120 s; d) And (3) carrying out vacuum hot-pressing treatment on the prepreg copper-clad foil to obtain the para-aramid nanofiber modified polytetrafluoroethylene glass fiber cloth high-frequency copper-clad plate.
2. The method according to claim 1, wherein the modification treatment in the step a) is: and mixing the silane coupling agent, an acidic medium and water to obtain a silane coupling agent solution, and then soaking the glass fiber cloth in the silane coupling agent solution for modification treatment to obtain the surface modified glass fiber cloth.
3. The preparation method according to claim 2, wherein an acidic medium is added into water, the pH value is adjusted to 3.0-4.0, and then a silane coupling agent is added to obtain a silane coupling agent solution; the mass concentration of the silane coupling agent solution is 0.2-0.5%, and the modification treatment time is 5-12 min.
4. The method according to claim 1, wherein the vacuum degree of the vacuum environment in the step C) is-1 to-0.90 Mpa.
5. The method according to claim 1, wherein the vacuum degree of the vacuum hot pressing treatment in the step D) is-1 to-0.93 MPa, and the hot pressing process curve is: The first stage, wherein the temperature is 80-120 ℃, the heat preservation time is 30-60 min, and the hot pressing pressure is 0MPa; the second stage, wherein the temperature is 220-240 ℃, the heat preservation time is 10-20 min, and the hot pressing pressure is 0MPa; the third stage, namely raising the temperature from 240 ℃ to 330 ℃, and pressurizing from 0-0.5 MPa to 3-4 MPa, wherein the pressurizing is completed in the process of raising the temperature; a fourth stage, namely heating the temperature from 330 ℃ to 350-380 ℃, gradually pressurizing from 3-4 MPa to 9-10 MPa, and finishing the pressurizing in the heating process; Fifth stage: the temperature is 350-380 ℃, the heat preservation time is 40-80 min, the hot pressing pressure is 9-10 MPa; And in the sixth stage, naturally cooling to 250-270 ℃, and then starting water cooling to quickly cool.
6. The p-aramid nanofiber modified polytetrafluoroethylene glass fiber cloth high-frequency copper-clad plate prepared by the preparation method according to any one of claims 1-5.

Description

Para-aramid nanofiber modified polytetrafluoroethylene glass fiber cloth high-frequency copper-clad plate and preparation method thereof Technical Field The invention belongs to the technical field of copper-clad plate preparation, and particularly relates to a para-aramid nanofiber modified polytetrafluoroethylene glass fiber cloth high-frequency copper-clad plate and a preparation method thereof. Background The 5G communication has the characteristics of high frequency, high-speed transmission, low delay, high-capacity storage and the like, and the copper-clad plate widely used in 5G equipment is required to have the characteristics of low dielectric constant, low dielectric loss, high thermal conductivity, good heat resistance, high reliability and the like. Polytetrafluoroethylene (PTFE) is a homopolymer of Tetrafluoroethylene (TFE), has a large molecular weight, typically several millions or more, and has a small radius of fluorine atoms and extremely high electronegativity, so that a carbon main chain in a molecular structure is almost tightly surrounded by fluorine atoms on both sides, which imparts very excellent insulation, dielectric properties, high heat resistance, chemical resistance, weather resistance, and the like to PTFE, and has extremely low dielectric loss at high frequencies. In the fifth sixty of the last century, the united states began to use the excellent dielectric properties of polytetrafluoroethylene to make high-frequency micro-application copper-clad plates, and up to now, PTFE copper-clad plates are one of the indispensable materials in the communication field. At present, a PTFE-based high-frequency copper-clad plate on the market generally uses ceramic powder modified polytetrafluoroethylene emulsion, and then glass fiber cloth is immersed in a ceramic powder modified polytetrafluoroethylene solution to prepare the copper-clad plate. However, the polarity of the surface of the polytetrafluoroethylene emulsion is extremely low, the polarity of the surface of the ceramic powder is high, the density of the ceramic powder is higher than that of the emulsion, the ceramic powder is easy to subside in the dipping process, the ceramic powder is easy to agglomerate in the drying process and is unfavorable for being uniformly dispersed in polytetrafluoroethylene particles, so that the dielectric constant and the thermal expansibility of the finally prepared copper-clad plate at different positions are different, the stability of the dielectric property of the copper-clad plate is affected, meanwhile, the dielectric constant of the ceramic powder is higher, and the dielectric constant of the copper-clad plate is higher due to the addition of a certain amount of ceramic powder, so that the requirement of the high-frequency copper-clad plate on low dielectric constant cannot be met. Disclosure of Invention The invention aims to provide a para-aramid nanofiber modified polytetrafluoroethylene glass fiber cloth high-frequency copper-clad plate and a preparation method thereof, wherein the para-aramid nanofiber modified polytetrafluoroethylene glass fiber cloth high-frequency copper-clad plate has low thermal expansion coefficient, ultralow loss (Df < 0.002) and stable dielectric property. The invention provides a preparation method of a para-aramid nanofiber modified polytetrafluoroethylene glass fiber cloth high-frequency copper-clad plate, which comprises the following steps: a) Modifying the glass fiber cloth by using a silane coupling agent to obtain surface modified glass fiber cloth; b) Immersing the surface-modified glass fiber cloth in an aramid nanofiber-modified polytetrafluoroethylene immersing liquid, taking out and drying to obtain an immersing glass fiber cloth; The aramid nanofiber modified polytetrafluoroethylene dipping solution is obtained by mixing polytetrafluoroethylene water dispersion emulsion and aramid nanofiber slurry; c) Sequentially stacking the gum dipping glass fiber cloth, and sequentially drying, removing impurities and sintering in a vacuum environment to obtain a prepreg; d) And (3) carrying out vacuum hot-pressing treatment on the prepreg copper-clad foil to obtain the para-aramid nanofiber modified polytetrafluoroethylene glass fiber cloth high-frequency copper-clad plate. Preferably, the modification treatment in the step a) is: and mixing the silane coupling agent, an acidic medium and water to obtain a silane coupling agent solution, and then soaking the glass fiber cloth in the silane coupling agent solution for modification treatment to obtain the surface modified glass fiber cloth. Preferably, adding an acidic medium into water, adjusting the pH value to 3.0-4.0, and then adding a silane coupling agent to obtain a silane coupling agent solution; the mass concentration of the silane coupling agent solution is 0.2-0.5%, and the modification treatment time is 5-12 min. Preferably, the silane coupling agent is gamma-glycidoxypropyl trimethoxysilane. Pr