Rugged flame-retardent laminates for military PCBs

The XT/duroid product line includes XT/duroid 8000 laminates for multilayer designs with as many as five layers and XT/duroid 8100 laminates for constructions with six or more circuit layers.

Both laminates feature thin halogen-free dielectrics and are available with low-profile copper foil cladding for use in double-sided and multilayer printed circuit boards (PCBs).

Low-profile copper bonded directly to the dielectric without the use of adhesives results in low insertion loss for these thin materials.

The reliable, flame-retardant laminates are thermally and chemically robust with very high melting points, making them suitable for harsh military and aerospace applications, including airborne lightning-strike protection circuits, phased-array antennas and unmanned aerial vehicles (UAVs).

These materials exhibit low outgassing characteristics, required for use in high-vacuum, deep-space applications.

Rogers' XT/duroid 8000 laminates feature a z-axis dielectric constant of 3.23+/-0.05 at 10GHz and a dissipation factor of 0.0035 or less at 10GHz.

They deliver stable electrical performance over wide frequency ranges, with a low thermal coefficient of dielectric constant of +7ppm/C from -50 to +150C and thermal conductivitiy of 0.35 W/m/K.

XT/duroid 8000 laminates can withstand extreme thermal conditions, with an estimated maximum operating temperature of greater than +210C and melt temperature well beyond that of PTFE-based circuit materials.

The circuit materials are designed for ease of processing and are compatible with lead-free-solder assembly methods.

For more complex multilayer circuit constructions requiring excellent stability, XT/duroid 8100 laminates benefit from the additional dimensional stability of a reinforced woven-glass resin system.

As a result, they can support multilayer circuits of six or more layers while providing the same electrical performance and ruggedness of XT/duroid 8000 laminates.

Both laminate materials are available with dielectric thickness of 0.002in (0.0508 mm) with 0.5-oz low-profile electrodeposited copper foil cladding.

XT/duroid 8100 is also available with dielectric thickness of 0.004 in (0.1016 mm).