A: Arlon’s nonwoven aramid (NWA) laminates offer world-class performance for CTE control. In response to needs for higher reliability and performance, Arlon has developed two substantially improved epoxy systems for NWA, both of which result in improved copper peel strength in finished clad laminates and PWB’s.
The best peel strength is achieved with the 55ST product, in which an interpenetrating polymer network achieves exceptional internal cohesion between the aramid fibers and resin, resulting in peel values of 10 lb/in for 1 oz (35 micron) Copper. 55ST was especially designed to minimize risk of pad lifting during G-forces generated by drop testing.
A second resin system, 55LM, exhibits 8 lb/in peels with 1 oz Cu, while also exhibiting extremely low moisture regain, comparable to multifunctional FR-4 and substantially improved over epoxy systems used with other NWA’s. This offers fabricators improved material handling while delivering a highly reliable circuit board for personal electronics and other CTE-sensitive applications.
As with Arlon’s other NWA products, 55ST and 55LM are lightweight (25% less than glass-epoxy), exhibit low in-plane CTE’s of 9-12 ppm/oC, excellent surface flatness and planarity and inherently resist CAF formation.
In addition, NWA’s exhibit good registration stability and inhibit resin microcracking due to random microfiber reinforcement, making it an ideal substrate for laser microvia and HDI applications. |
