Newly improved polymer alloy systems for printed wiring boards

A novel laminating resin system using polymer alloy technologies was investigated to see if it could meet demands of high density printed wiring boards. An experimental study was carried out on thermoplastic and thermosetting polymer alloy systems. Two combinations of linear phenoxy resin and thermosetting epoxy resin were characterized to investigate the synergetic qualities of the resin systems. For one system better mechanical properties were achieved when the content of phenoxy resin was not above 30%. No phase separation was observed in this region. Results on the gel fraction and crosslinking density of the systems support the speculation that the linear chains of phenoxy resin are interpenetrated into the network chains of the epoxy resin. The other combination of heat-resistant epoxy resin and phenoxy resin required smaller amounts of phenoxy resin to achieve homogeneous structure. The adequate phenoxy resin content for achieving better mechanical properties was determined.<>