PTFE Materials
The AD series woven fiberglass-reinforced polytetrafluoroethylene (PTFE) materials for microwave PCBs are designed for high volume commercial applications. Electrical and mechanical performance of the materials are comparable to most MIL Spec PTFE materials, including a dielectric constant range from 2.5 to 3.6 (depending on material) and loss values in the 0.002 to 0.003 range. Higher tensile modulus (700 kpsi) and lower thermal coefficients of expansion result in improved dimensional stability during processing assembly. Water absorption is 0.07 percent. The materials are offered in selected standard thicknesses from 0.020 with 0.50, 1 or 2 oz electrodeposited copper on both sides.
Arlon, Materials for Electronics,
Bear, DE
(800) 635-9333 or (302) 834-2100.

Thermal Management Materials
Several thermal management materials are available on the company’s alumina/glass side-wall packages. The new package design incorporates the brazing of thermally conductive material to the bottom of the packages. Materials offered include copper/tungsten, molybdenum, copper/molybdenum, aluminum silicon carbide and beryllium/oxide.
Mini-Systems Inc., Electronic Package Division,
Plainville, MA
(508) 695-2000.