Arlon’s 55NT is an epoxy laminate and prepreg system, reinforced with a non-woven aramid reinforcement. This system combines compatibility with leadfree processing, using a high temperature multifunctional epoxy resin, with the low in-plane (X,Y) expansion of 6-9 ppm/⁰C and outstanding dimensional stability of non-woven aramid reinforcement. Polymeric reinforcement results in PCBs is typically 25% lighter in weight than conventional glass-reinforced laminates. Meets requirements of IPC-4101/55.
Process inner-layers through develop, etch, and strip using standard industry practices. Use brown oxide on r inner layers. Adjust dwell time in the oxide bath to ensure uniform coating. Bake inner layers in a rack for 60 minutes at 107°C - 121°C (225°F - 250°F) immediately prior to lay-up. Vacuum desiccate the prepreg for 8 - 12 hours prior to lamination.
- Pre-vacuum for 30 - 45 minutes
- Control the heat rise to 4.5°C - 6.5°C (8°F - 12°F) per minute between 100°C and 150°C (210°F and 300°F). Vacuum lamination is preferred. Start point vacuum lamination pressures are shown in the table below.
- Product temperature at start of cure = 182°C (360°F)
- Cure time at temperature = 90 minutes
- Cool down under pressure at ≤ 6°C/min (10°F/min)
- De-smear using alkaline permanganate or plasma with settings appropriate for polyimide; plasma is preferred for positive etchback
- Conventional plating processes are compatible with 55NT
- Standard profiling parameters may be used; chip breaker style router bits are not recommended
- Bake for 1 - 2 hours at 250°F (121°C) prior to solder to reflow of HASL