Encapsulated backplate for electret transducers

摘要

Electrically conductive sheets comprising backplates for electret transducers are substantially encapsulated with hydrophobic electrically insulating coatings. The coatings are melt bonded to both faces of the sheets and to the edges of the sheet periphery. Likewise, the coatings are melt bonded to the interior edges of acoustic apertures in the sheets.