초록 |
Phenol-formaldehyde novolac is one of the promising materials for high glass transition (Tg) copper clad laminates (CCL). Recently, however, CCL manufacturers suffer from high viscosity and fast curing characteristic of high Tg novolacs because they have high molecular weights and high polydispersity (PDI). To solve this problem, bisphenol-F (BPF) removed narrow polydispersity novolac (ND-novolac) which has lower molecular weight and PDI than conventional High Tg novolacs was prepared by short path distillation. It was expected that removing of BPF in lower molecular weight novolac would enhance thermal properties without drastic increase in viscosity. As expected, ND-novolac showed lower viscosity and slower curing characteristics when compared to conventional straight novolac resin which has similar softening point. Furthermore, there were no significant losses in overall CCL performances. Wettability evaluated by contact angle measurement was also excellent. |