1 Scope The purpose of this test method is to measure thethickness and phosphorous (P) concentration of chemically(electroless) deposited nickel (Ni) coatings by (energy dispersive) X-ray fluorescence (XRF) analysis.The measurement is nondestructive and noncontact, and canbe performed either in ambient atmosphere or under vacuum.Measurements shall be made on a defined feature (equivalent to a typical SMT pad) of 1.5 mm x 1.5 mm [0.060 in x0.060 in] or equivalent area, using a 0.6 mm diameter collimator. This equates to a measuring spot size (analysis area) of1 mm diameter.This test method is designed primarily for failure analysis, process qualification and process auditing. It is not intended fordaily production control, due to the complexity and cost of theequipment required.