In answer to numerous industry requests for guidance on Electroless Nickel-Immersion Gold (ENIG), the IPC-4552 has been developed. Containing full color photographs, this specification sets the requirements for the use of ENIG as a surface finish for printed circuit boards. It includes requirements for ENIG deposit thicknesses based on performance criteria. It will be an invaluable resource for use by suppliers, board fabricators, electronics manufacturing services (EMS) and original equipment manufacturers (OEMs). The immersion gold protects the underlying nickel from oxidation or passivation over its intended life. It is a multifunctional surface finish, applicable to soldering, aluminum wire bonding, press fit connections, and as a contact surface. 29 pages. Released October 2002.