Low dielectric material for multilayer printed wiring boards

A low-dielectric material for high-speed digital multilayer printed wiring boards (MPBs), maleimide-styryl (MS) resin, was developed by reacting styryl prepolymer with ether-type bismaleimide. Since MS resin has good processabilities, prepregs and copper clad laminates can be made under conventional conditions used for epoxy and polyimide laminates. The laminates are characterized by their excellent heat-resistant properties, which are almost the same as those of polyimide laminates, and low moisture absorption, which is the same as that of epoxy laminates. The laminates comprising the MS resin and several reinforcements have low dielectric constants, ranging from 3.3 to 3.7. Using the laminates, a high-density MPB with 62 printed wiring layers was made.<>