Low dielectric material for multilayer printed wiring boards

A low-dielectric material called maleimide styryl (MS) resin is discussed. It was developed by reacting styryl prepolymer with ether-type bismaleimide. Both the styryl prepolymer and the ether-type bismaleimide are compounds based on the relationship between the chemical structure and dielectric constant. Since MS resin has good processabilities, its prepregs and copper-clad laminates can be made under the conventional processing conditions of epoxy and polyimide laminates. The MS laminates are characterized by their excellent heat resistance, similar to that of polyimide laminates, and low moisture absorption, similar to that of epoxy laminates. The laminates consist of the MS resin and several reinforcements having low dielectric constants ranging from 3.3 to 3.7. A high-density multilayer printed board with 62 printed wiring layers was made using the laminates; its capabilities are discussed