C-shield parylene allows major weight saving for EM shielding of microelectronics

Abstract

Parylene is a conformal polymer film that has been used as a protective conformal coating for more than 25 years. It provides environmental and dielectric isolation in a variety of applications, industrial and automotive sensors, electronic circuits, hybrids, various medical substrates, and is also used extensively for corrosion protection and electrical insulation of ferrites and magnets. The most important performance specifications for a conformal coating are (1) uniformity and completeness of coverage, and (2) physical, electrical, chemical, mechanical, and barrier properties. Parylene offers significant performance capabilities in both of these areas. As a nonsolvent based coating, parylene is not affected by volatile organic compound (VOC) restrictions, and it is not implicated in the ozone depletion concerns of the Montreal Protocol and other environmental legislation. The parylene vacuum condensation process is now also capable of producing a dissipative parylene 'C-shield' that allows packaging of microelectronics with both the environmental protection offered by parylene and the dissipation of undesired stray EM radiation. This eliminates encapsulation with metal boxes and allows major cost and weight savings.