Standard Specification for Autocatalytic Nickel over Autocatalytic Copper for Electromagnetic Interference Shielding

Abstract

This specification covers the requirements for multilayer coatings of autocatalytic nickel-phosphorus over autocatalytic copper intended for electromagnetic interference or electrostatic discharge shielding to parts fabricated from either polymeric or metallic substrates or parts. Coatings are classified into four types based on thickness and testing requirements, and into two grades based on alloy composition, specifically phosphorus. Surfaces shall be prepared by cleaning it of surface contaminants, conditioning, and activation; identifying of base material suitability; and mechanical roughening. Coatings shouldl be inspected for process qualification, appearance, blisters, unplated areas, adhesion, electrical continuity, and DC resistance. Coatings should also be tested for thickness, which may be performed either by Coulometric, X-ray, or Beta backscatter methods. The requirements for process qualification shall include coating composition, electrical integrity, adhesion, thermal shock resistance, thermal cycling, and shielding effectiveness.