IPC-4553, Specification for Immersion Silver Plating for Printed Circuit Boards, is the second document in a series of specifications (the first being IPC-4552 which addresses Electroless Nickel / Immersion Gold) that set the requirements for printed circuit board surface finishes that are alternates to eutectic tin lead. This IPC-4553 specification establishes metrics for immersion silver (IAg) deposit thickness based on performance criteria and illustrates the requirements using full color photographs and illustrations for clarity. Included as appendices, this document also provides the user with a well written, explanatory paper by Gerard O'Brien and George Milad, entitled: "Standard Developments Efforts of Immersion Silver" as well as an excellent tutorial, entitled "X-Ray Fluorescence (XRF) Spectroscopy" by Frank Ferrandino that provides information on this analytical equipment's use as a plating thickness control mechanism. IPC-4553 is intended for use by suppliers, printed circuit manufacturers, electronics manufacturing services (EMS) providers and original equipment manufacturers (OEM). 29 pages. Released June 2005.