Preparation method of PTFE (polytetrafluoroethylene) copper-clad plate with high elastic modulus

Abstract

The invention provides a preparation method of a PTFE (polytetrafluoroethylene) copper-clad plate with a high elastic modulus, which comprises the following steps of: preparing copper foil and glass fiber cloth with a low dielectric constant, and preparing a fluororesin mixture; soaking the glass fiber cloth with the prepared fluororesin mixture, transferring the soaked glass fiber cloth into a baking oven for baking and drying, and repeating the steps to enable the glass fiber cloth to be soaked, baked and dried many times, thereby obtaining soaking pieces the resin content of which is about 60-70%; and superposing the soaking pieces, coating the copper foil on two sides, and laminating to obtain the PTFE copper-clad plate. The baking and drying process comprises three stages, wherein the temperature of the baking oven in the first stage is 50-100 DEG C, the temperature of the baking oven in the second stage is 200-320 DEG C, and the temperature of the baking oven in the third stage is 380-400 DEG C. The plate prepared by the method provided by the invention not only has a lower dielectric constant but also has a higher elastic modulus, and the plate has the advantages of consistent internal structure and good dimensional stability.

Description

technical field [0001] The invention relates to a method for preparing a copper-clad laminate, in particular to a method for preparing a PTFE copper-clad laminate with a high elastic modulus. Background technique [0002] Since the commercial production of polytetrafluoroethylene (PTFE) by DuPont in 1945, due to the unique physical and chemical properties of this material, people have continuously developed the application of this material in various fields, among which the excellent dielectric properties of PTFE material are used Performance (low dielectric constant and low dielectric loss) has been used to manufacture copper clad laminates for high frequency applications for many years. The most traditional manufacturing method is PTFE emulsion impregnated glass fiber cloth, and then several PTFE impregnated cloths are superimposed, and the copper clad layer The PTFE copper clad laminate can be obtained by pressing, but this manufacturing method relies on increasing the re...

AI Technical Summary

Problems solved by technology

[0002]Since polytetrafluoroethylene (PTFE) was commercialized by DuPont in 1945, due to the unique physical and chemical properties of this material, people have been continuously developing this material. The application of materials in various fields, among which the excellent dielectric properties (low dielectric constant and low dielectric loss) of PTFE materials have been used to manufacture copper-clad laminates for high-frequency applications has been used for many years. The most traditional manufacturing method is PTFE emulsion impregnated with glass fiber Cloth, then several sheets of PTFE impregnated cloth are superimposed, and the copper clad foil is laminated to obtain a PTFE copper clad laminate, but this manufacturing method relies on increasing the resin content of the board to obtain a low dielectric constant, and the higher the resin content, the higher the board's The modulus of elasticity drops

In addition, PTFE is a thermoplastic resin, and its elastic modulus is very low. Therefore, the elastic modulus of PTFE copper-clad laminates prepared by traditional methods is much lower than that of ordinary copper-clad laminates (FR-4) with the same structure, and the elastic modulus is too high. Low will seriously affect its processability and reliability

How to obtain both modulus and dielectric constant, people have also carried out some attempts, such as U.S. Patent 4895752 / 1990, using organic fibers with lower dielectric constants - aramid fibers to impregnate PTFE emulsion to produce low dielectric Constant high modulus PTFE copper clad laminate, but this technology has the disadvantages of high price of aramid fiber and relatively poor heat resistance, so it has not been popularized and applied; US Patent 6417459 / 2002 invented a PTFE / glass fiber cloth impregnated sheet with copper The method of placing a PFA film between the foils to increase the resin content of the sheet, because PFA has a relatively higher elastic modulus than PTFE, so the sheet has a lower dielectric constant and a higher elastic modulus, but this technology There are problems such as inconsistent internal structure and easy flow of PFA film during lamination, which affects the uniformity of sheet thickness.