Use of inorganic thin non-woven dielectrics in printed circuit boards

A printed circuit board, comprising:

• at least one dielectric material layer comprising a non-woven, inorganic fabric reinforcement impregnated with a crosslinked thermosetting polymer resin, the crosslinked thermosetting polymer resin having a density of less than about 1.6 g/cc and a dissipation factor (DF) of less than about 0.010,
• wherein the at least one dielectric material layer has a thickness of less than about 125 microns upon lamination and is characterized by:
• a thickness reduction of at least 25% relative to a thickness of the non-woven, inorganic fabric reinforcement prior to lamination;
• a glass transition temperature (Tg) of greater than about 150° C.;
• a coefficient of thermal expansion (CTE) of less than about 35 ppm in either of the planar directions over a temperature range of about 50° C. to about 220° C.;
• and
• a dielectric constant (DK) of less than about 3.5.