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CN-121975378-A - Polytetrafluoroethylene copper-clad plate base material and preparation method thereof

CN121975378ACN 121975378 ACN121975378 ACN 121975378ACN-121975378-A

Abstract

The invention belongs to the field of circuit board materials. The invention provides a polytetrafluoroethylene copper-clad plate substrate and a preparation method thereof, wherein the raw materials comprise main resin polytetrafluoroethylene emulsion, a filling component and an auxiliary agent, the filling component comprises spherical silicon oxide with the specific surface area of 0.45-1.25 m 2 /g and titanium oxide with the specific surface area of 0.5-1.0 m 2 /g, and the auxiliary agent comprises a surfactant and a coupling agent. The polytetrafluoroethylene copper-clad plate substrate has a fixed dielectric constant, the coefficient of thermal expansion CTE of the polytetrafluoroethylene substrate is obviously reduced and is close to that of copper foil, the CTE is ensured to be close to 18 ppm/DEGC, and the conventional performance is not affected.

Inventors

  • JIANG JIANYONG
  • GU SIFAN
  • PAN JIAYU

Assignees

  • 清融新材料科技(嘉兴)有限公司

Dates

Publication Date
20260505
Application Date
20260311

Claims (9)

  1. 1. A polytetrafluoroethylene copper-clad plate substrate is characterized in that the substrate comprises main resin polytetrafluoroethylene emulsion, a filling component and an auxiliary agent, wherein the filling component comprises spherical silicon oxide with the specific surface area of 0.45-1.25 m 2 /g and titanium oxide with the specific surface area of 0.5-1.0 m 2 /g, and the auxiliary agent comprises a surfactant and a coupling agent.
  2. 2. The polytetrafluoroethylene copper-clad plate substrate according to claim 1, wherein the density value of the polytetrafluoroethylene copper-clad plate substrate is 2.10+/-0.05 g/cm 3 .
  3. 3. The polytetrafluoroethylene copper-clad plate substrate according to claim 1, wherein the polytetrafluoroethylene copper-clad plate substrate comprises the following components in parts by weight, 50-80 Parts of polytetrafluoroethylene resin emulsion (solid content is 35-65%); 0-5 parts of titanium oxide with the specific surface area of 0.66m 2 /g; 10-60 parts of spherical silicon oxide with specific surface area of 1.2m 2 /g; 10-60 parts of spherical silicon oxide with the specific surface area of 0.7m 2 /g; 10-60 parts of spherical silicon oxide with the specific surface area of 0.5m 2 /g; 0.02-0.04 part of auxiliary agent.
  4. 4. A polytetrafluoroethylene copper-clad plate substrate according to claim 3, wherein the average particle diameter of PTFE in the polytetrafluoroethylene resin emulsion is less than 0.5 μm.
  5. 5. A method for preparing a polytetrafluoroethylene copper-clad plate substrate according to claim 1, comprising the following steps, (1) Weighing each component, diluting the auxiliary agent with deionized water, adding the diluted auxiliary agent into polytetrafluoroethylene resin emulsion, uniformly mixing, adding spherical silicon oxide and titanium oxide as filling components, uniformly mixing the components in the order of from small to large specific surface area, adjusting viscosity, and eliminating internal bubbles to obtain slurry; (2) And (3) coating the copper-clad plate base material slurry prepared in the step (1) with films, and performing heat treatment at different temperature sections to dry the surfaces of the films, remove water and rearrange crystals to obtain the polytetrafluoroethylene copper-clad plate base material.
  6. 6. The method according to claim 5, wherein in the step (2), the heat treatment comprises the steps of baking at 65-85 ℃ for 3-10min, heating to 105-135 ℃ for 3-10min, heating to 330-385 ℃ and sintering for 3-10min.
  7. 7. The method of preparing according to claim 5, wherein the step (1) of adjusting the viscosity comprises the step of adjusting the viscosity to 400-600cps with deionized water.
  8. 8. A method for preparing a high-frequency high-speed polytetrafluoroethylene-based copper-clad plate is characterized by comprising the following steps of taking at least one or more polytetrafluoroethylene copper-clad plate base materials prepared by the preparation method according to claim 1 or the preparation method according to claim 5, respectively attaching copper foils on the upper and lower surfaces of the base materials or the upper and lower surfaces of the base materials after being overlapped up and down, and placing the base materials in a vacuum hot press for pressing to prepare the high-frequency high-speed copper-clad plate.
  9. 9. The method for preparing a high-frequency and high-speed polytetrafluoroethylene-based copper-clad plate according to claim 8, wherein the lamination procedure of the vacuum hot press comprises the following steps, A rapid heating section, wherein the temperature is between room temperature and 310 ℃, the pressure is between 3 and 5MPa, and the hot pressing is carried out for 30 to 50 minutes; a high-temperature hot-pressing section, wherein the temperature is 350-385 ℃, the pressure is 13-16.5MPa, and the hot pressing is carried out for 1-3 h; And the pressure maintaining and cooling section is to perform hot pressing for 1-3 hours, wherein the temperature is 385 ℃ to room temperature and the pressure is 13-16.5 MPa.

Description

Polytetrafluoroethylene copper-clad plate base material and preparation method thereof Technical Field The invention belongs to the field of circuit board materials, and particularly relates to a polytetrafluoroethylene copper-clad plate base material and a preparation method thereof. Background In multilayer circuit boards, high Coefficient of Thermal Expansion (CTE) boards are prone to hole site offset or glass fiber tear due to thermal expansion during drilling, while CTE in the Z-axis is too high, resulting in interlayer thermal stress build up, and delamination during high temperature lamination or reflow. When the copper plated hole (PTH) is used for high-frequency boards such as 5G base stations and satellite antennas, if the CTE of the board is large in difference with that of copper foil, the copper layer on the wall of the hole in temperature circulation can be broken due to stress, so that signals are interrupted. Therefore, the closer the CTE is to that of the copper foil, the better the risk of separating the hole copper can be reduced, and the stability of high-frequency signal transmission is ensured. Pure Polytetrafluoroethylene (PTFE) has a very high CTE, about 200-300 ppm/°c, because its molecular chains are compliant and free of strong cross-linking, and readily swells at high temperatures. Ceramic fillers generally have CTE within 10ppm/°c, much lower than PTFE. Therefore, the CTE of the PTFE-based copper clad laminate can be reduced by filling the high stability inorganic ceramic particles, but it is difficult to make the dielectric constant at a fixed value without affecting the conventional properties. Disclosure of Invention In order to solve the technical problems, the invention provides a polytetrafluoroethylene copper-clad plate substrate and a preparation method thereof. The polytetrafluoroethylene copper-clad plate substrate has the advantages that the thermal expansion coefficient is obviously reduced, the thermal expansion coefficient is close to that of copper foil, the substrate has a fixed dielectric constant, and the conventional performance is not affected. The invention aims to provide a polytetrafluoroethylene copper-clad plate substrate, which comprises main resin polytetrafluoroethylene emulsion, a filling component and an auxiliary agent, wherein the filling component comprises spherical silicon oxide with the specific surface area of 0.45-1.25 m 2/g and titanium oxide with the specific surface area of 0.5-1.0 m 2/g, and the auxiliary agent comprises a surfactant and a coupling agent. In the invention, the silicon oxide is preferably of a spherical structure, on one hand, in order to reduce the interface loss between the filler and the resin, on the other hand, in order to increase the filling amount of the filler, the titanium oxide can meet the requirement that the dielectric constant Dk value of a copper-clad plate substrate is fixed to be 3.0+/-0.04, the surfactant reduces the interfacial tension and promotes the short-term dispersion and wetting of the filler in the resin, and the coupling agent bridges an inorganic phase and an organic phase through chemical bonds, so that the compatibility of the filler and the resin is improved. Under the synergistic effect of the components, the polytetrafluoroethylene copper-clad plate substrate has a fixed dielectric constant, and the coefficient of thermal expansion CTE of the polytetrafluoroethylene substrate is obviously reduced. The density value of the polytetrafluoroethylene copper-clad plate substrate is 2.10+/-0.05 g/cm 3. Further, the polytetrafluoroethylene copper-clad plate base material comprises the following components in parts by weight, 50-80 Parts of polytetrafluoroethylene resin emulsion (solid content is 35-65%); 0-5 parts of titanium oxide with the specific surface area of 0.66m 2/g; 10-60 parts of spherical silicon oxide with specific surface area of 1.2m 2/g; 10-60 parts of spherical silicon oxide with the specific surface area of 0.7m 2/g; 10-60 parts of spherical silicon oxide with the specific surface area of 0.5m 2/g; 0.02-0.04 part of auxiliary agent. Preferably, the coupling agent in the auxiliary agent is KH550, and the surfactant is triton. Preferably, the PTFE in the polytetrafluoroethylene resin emulsion has an average particle size of less than 0.5 μm. More preferably, the PTFE has an average particle size of less than 0.2. Mu.m. The invention also aims to provide a preparation method of the polytetrafluoroethylene copper-clad plate base material, which comprises the following steps, (1) Weighing each component, diluting the auxiliary agent with deionized water, adding the diluted auxiliary agent into polytetrafluoroethylene resin emulsion, uniformly mixing, adding spherical silicon oxide and titanium oxide as filling components, uniformly mixing the components in the order of from small to large specific surface area, adjusting viscosity, and eliminating internal bubbles to obtain slurry;