Purpose: This specification covers requirements for poly-monochloro-paraxylylene coatings. Application: Primarily for use as a secondary moisture barrier coating on hybrid microcircuit substrates and on active monolithic devices. Additionally@ the coating immobilizes undesirable particles remaining in sealed microcircuits and enhances to some degree the strength of fine wire interconnections. Safety - Hazardous Materials: While the materials@ methods@ applications@ and processes described or referenced in this specification may involve the use of hazardous materials@ this specification does not address the hazards which may be involved in such use. It is the sole responsibility of the user to ensure familiarity with the safe and proper use of any hazardous materials and to take necessary precautionary measures to ensure the health and safety of all personnel involved.