Issue link: https://iconnect007.uberflip.com/i/1411055
76 PCB007 MAGAZINE I SEPTEMBER 2021 suggest technical or editorial changes. All com- ments are then reviewed, and all issues are re- solved before the "Final Dra" is issued. At this time, the IPC takes on the task of publishing the document in its final format. e IPC Plating Subcommittee 4-14 was active from 2001–2019. The committee was co-chaired by myself and Gerard O'Brien, president and owner of ST&S Group, a con- sulting and testing facility. e IPC liaison was Tom Newton. e committee had an exten- sive member list composed of OEMs, assem- bly manufacturers, suppliers, labs, and consul- tants. Members participated on and off in con- ference calls that they were interested in and as their time allowed. Not all members were on all conference calls. Below is a listing of participant companies. OEM and CM: Lockheed Martin, Raytheon, Oracle, ADTRAN, Rockwell Collins, Hewlett- Packard, Alcatel-Lucent, Dell, St. Jude Med- ical, Delphi, Schneider Electric, Continen- tal Corporation, Panasonic, IBM, Northrop Grumman, BAE Systems, Honeywell, Boe- ing, Tyco Electronics, Peregrine Semiconduc- tor, Space Systems /Loral, Amonix, Celestica, Winstron. PCB manufacturing: TTM, I3, Molex, Bergquist, Superior Processing, Alternate Fi- nal Finishing. Suppliers: MacDermid, Uyemura, Atotech, Technic Inc, MEC, ECI Technology, Kulick & Sofa, Metalor, Fischer Technology, Hesse-Me- chatronics. Labs and Consultants: ST&S Group, Sandia Laborator ies, DFR Solutions, TAS Consulting. e committee met every other week for a one-hour conference call. ose in attendance made decisions. e minutes of the meeting were documented and distributed to the mem- bers. Since its inception, the IPC Plating Subcom- mittee 4-14 has issued the following: • IPC-4552 ENIG Specification 2002 • IPC-4553 Immersion Silver specification 2005 • IPC-4554 Immersion Tin Specification 2007 • IPC-4553A Revised Immersion Silver 2009 • IPC-4554 Amended Tin Specification 2011 • IPC-4552 Amended ENIG Specification 2012 • IPC-4556 ENEPIG Specification 2013 • IPC-4556 ENEPIG Amended Specification 2015 • IPC-4552 Rev A ENIG Specification 2017 • IPC-4552 Rev B ENIG Specification 2021 e ENIG IPC-4552 Specification was is- sued in 2002. No lead-free (LF) solder was in use at that time. For thickness, IPC-4552 stated: • e EN thickness shall be 3 to 6 µm (118.1 to 236.2 µin) • e minimum IG thickness shall be 0.05 (1.97 µin) at four sigma (standard deviation) below the mean. e typical range is 0.075 to 0.125 µm (2.955 to 4.925 µin) • No upper limit was set Immersion Silver IPC-4553 issued in 2005. In 2005, there were two distinct types of com- mercialized immersion silver with differ- ent thickness recommendations, referred to as "in" and "ick." Each required its own thickness specification. e initial 4553 specification stated the fol- lowing for thickness of deposit. Two thickness specification: • in silver: 0.05 µm (2 µ") minimum at -2σ from process mean as measured on a pad of area 2.25² µm (3600² mils). Typical value 0.07 µm (3 µ") to 0.1 2µm (5 µ") • ick silver: 0.12 µm (5 µ") minimum at -4σ from process mean as measured on a pad of area 2.25 µm (3600² mils). Typical value of 0.2 µm (8 µ") to 0.3 µm (12 µ"). e immersion tin specification was issued in