A highly-crosslinked phthalonitrile modified bismaleimide-triazine resin for PCB substrates: The synergistic effect on curing behavior and properties

In view of the problems of difficult processing and poor toughness, bismaleimide-triazine (BT) resin was modified by the 4-(4-amino-phenoxy)phthalonitrile (4-APN). The effect of 4-APN on the curing behavior of BT resin was investigated, followed by the calculated activation energy. The possible curing mechanism of the ternary system was also proposed, with the further study of the relationship between chemical structures and properties. The results showed that 4-APN can increase the reactivity and decrease the curing temperature of BT resin. Due to the fact that 4-APN exerted a thermal synergistic curing effect on the BT resin, poly(BT/APN)s with a heterocyclic network and the high crosslinking density exhibited the superior overall performance. First, the high heat-resistance of poly(BT/APN)s was displayed, especially the glass transition temperature up to 347 ℃ of poly(BT/30APN). More intriguingly, poly(BT/APN)s with a breakdown strength of 119 kV/mm possessed better insulation properties, and the dielectric constant and loss reduced to 3 and 0.005 (1 MHz), respectively, while remaining a good stability at high temperature. Additionally, the moisture resistance and toughness of poly(BT/APN) also significantly improved. Based on these merits, poly(BT/APN) can be considered as an ideal material for microelectronics.