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
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