The ENTEK PLUS CU-106A thickness range is specified by Enthone-OMI to be
0.2 to 0.5 microns.  Nominal should actually be 0.35 to 0.40.  We run ours
fairly tight at 0.38 to 0.42.

Electrical testing should be done prior to applying the coating.  The last
thing a fabricator should do prior to packaging OSP cards for shipping is
to apply the coating as minimizing the amount of handling of ANY solderable
surface is critical.  If you must test after the coating has been applied,
use a pin which will get through the coating.

For more information, please check out Enthone-OMI's web site at
http://www.enthone-omi.com and request the booklet entitled Answers to Key
Assembly Questions.

Regards.

Tom Eshelman
Process Engineer
Triangle Circuits of Pittsburgh
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----------
> From: [log in to unmask]
> To: [log in to unmask]
> Subject: Re: [TECHNET] OSP coating
> Date: Monday, September 01, 1997 1:32 AM
>
>      Hello Technetters,
>
>      A colleague and I have been facing some problems  in Circuit testing
>      with 2 types of  boards that have OSP coating. There has been a low
>      First time pass yield at approx 40% due to the thickness of the OSP
>      coating, which we are specifying to the PCB manufacturers to be in
the
>      range of 0.2-0.25 um.
>
>      The  OSP coating is Entek Plus type 106 and the type of pin material
>      used on these OSP boards are High conductivity steel made by QA
>      technologies.
>      The Incircuit tester used is HP 3070 series II with vaccum fixturing
>      and the total pin count is 2004 pins on one board type and 1443 on
>      another. Test time is approximately 1-2 minutes per board, and the
>      failure if faused by poor pin contact will occur within the first 30
>      seconds of testing.
>
>      We have been trying some alternative pin types ie. rotating flux
>      buster type pins. Has any one out there used this pin type or any
>      other that has increased the success rate on the FTPY?
>
>      Does anyone have any suggestions on
>
>      - alternative pin types and manufacturers
>      - changes to the test fixturing to help resolve this problem
>      - information on how to ensure while manufacturing these boards, osp
>      coating proceses are controlled to get the right coating thickness.
>
>
>      Thanks and regards
>
>      Arjunan Murthy
>      [log in to unmask]