IPC-4553A Immersion Silver Specification Released

Companies using immersion silver as a surface finish for printed boards have a new tool in the new revision of IPC-4553A, Specification for Immersion Silver Plating for Printed Boards. New in this release is a maximum deposit thickness and the elimination of the distinction between “thin” and “thick” that was included in the original document release.

The maximum deposit thickness change is the result of an expansive program of round robin testing as detailed in the free download TR-586 (.pdf) to find an appropriate top limit. The delineation between “thin” and “thick” deposits was eliminated due to the movement in the industry away from “thin” finishes and feedback from industry users on confusion in using the document. Kudos to the members of the 4-14 Plating Processes Subcommittee, chaired by Gerard A.O’Brien, Solderability Testing & Solutions, Inc. and George Milad, Uyemura International Corp., for their hard work.

The committee is now working on advancing the IPC-4555 standard that addresses organic solderability preservative (OSP) surface finish and is also soon to canvas the membership on the need for generating an industry standard on a newer surface finish for printed boards: electroless nickel/electroless palladium/immersion gold (ENEPIG).

 Here is a link to IPC-4553A in the IPC online store, which includes a detailed description and link to the table of contents.

3 Comments

  1. Pat Hamilton
    Posted August 10, 2011 at 4:16 pm | Permalink

    I am interpreting the immersion silver thickness spec stated IPC 4553 section 3.2.1 to be if I measure a sample of PCBs the mean of that sample must within the limits and be greater that 4δ away from both lower (0.12µm) and upper (0.4µm) spec limits. Is this a correct interpretation?

    • Kim Sterling
      Posted August 12, 2011 at 1:56 pm | Permalink

      Hi Pat – Here is the information from our Director of PCB Programs, Standards and Technology:

      Your interpretation is correct, but I want you to make sure that the cautionary about surface pad size of
      2.25 mm2 (nominally, 1.5 mm X 1.5 mm) shall be followed for every individual measurement made.
      Also of course, the XRF equipment must be fully calibrated by being traceable to certified immersion
      silver standards whenever it is utilized.

      If you have further questions about IPC-4553A, please do not hesitate to contact either of the 4-14
      Plating Processes Subcommittee Co-Chairs, George Milad or Gerard O’Brien with their contact
      information shown next:

      George Milad
      National Accounts Mgr for Technology
      Uyemura International Corp.
      240 Town Line Rd
      Southington, CT 06489-1145
      W: 860-793-4011 x226
      M: 516-901-3874
      F: 860-793-4020
      gmilad@uyemura.com
      &
      Mr. Gerard A. O’Brien
      President
      Solderability Testing & Solutions, Inc.
      Reliability & Technology
      108 Rosedale Ave
      Richmond, KY 40475-1039
      W: 631-868-0740
      gobrien@standsgroup.com

      Best Regards;

      Thomas D. Newton
      Director PCB Programs, Standards and Technology
      IPC – Association Connecting Electronics Industries
      3000 Lakeside Drive
      Suite 309-S
      Bannockburn, IL 60015-1249 USA
      +1 847-597-2849 tel
      +1 847-615-7105 fax
      TomNewton@ipc.org
      http://www.ipc.org

  2. Osiris Valenzuela
    Posted January 16, 2013 at 10:59 am | Permalink

    I have a question related to tarnish on silver immersion finish, is this consider to be an acceptable or reject condition? Also after doing an SEM analysis, what it is expected to be detected on this analysis? Is it Chlorine expected? If not what proportion of this can be considered as “normal”?
    Appreciate your help.

    Regards.


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