The improved moistureproof structure for a module circuit is characterized in that a porous film conditioned to have an apparent relative dielectric constant of no more than 2.0 is coated over a stripline a high-frequency circuit, or a high-frequency device formed on a substrate, which porous film may...http://www.google.fr/patents/US5276414?utm_source=gb-gplus-shareBrevet US5276414 - Moistureproof structure for module circuits
