LOW DIELECTRIC MATERIAL FOR MULTILAYER PRINTED WIRING BOARDS

For high-speed digital multilayer printed wiring boards (MPB's), a low dielectric material, maleimide-styryl (MS) resin was developed by reacting styryl prepolymer with ether-type bismaleimide. Both the styryl prepolymer and the ether-type bismaleimide are newly designed 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, are similar to that of polyimide laminates and low moisture absorption, and are the same as that of epoxy laminates. The laminates which consist of the MS resin and several reinforcements have low dielectric constants ranging from 3.3 to 3.7. Furthermore, by using the laminates, a high density MPB with 62 printed wiring layers was made and its good capabilities were confirmed. © 1990 IEEE