| abstract |
Disclosed is a high-frequency copper foil covered substrate used in an operational frequency of at least 1 GHz and having the properties of dielectric constant (Dk) less than 3.2, dissipation factor (Df) less than 0.005, high glass transition temperature, high thermal stability and low moisture absorption. The high-frequency copper foil covered substrate comprises special composite material obtained by a reinforcement material impregnated with a formulated resin mixture. The resin mixture in the composite material is formulated by (a) high-molecular-weight polybutadiene resin (b) low-molecular-weight polybutadiene resin, (c) modified thermosetting polyphenylene ether resin, (d) inorganic powder, (e) flame retardant, (f) crosslinker, (g) adhesion aid and (h) curing initiator, thereby improving the drawbacks related to the poor workability of pure polybutadiene having excessively high adhesiveness and the need of adding plasticizer into polyphenylene ether resin (PPE) due to low solubility. In particularly, a tack-free prepreg can be prepared by the composite material and the copper foil covered substrate also can be prepared by the composite material by using an automatic process. |