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Reply To: | TechNet Mail Forum. |
Date: | Thu, 4 Sep 1997 09:43:36 +0300 |
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Hi,
You wrote:
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]
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Have you already tried test probes made by Ingun ?
My former employer used them without any big problems in IC- testing (
See http://www.cyberpoint.co.uk/ingun/ )
Boards were multilayer boards, 2-sided reflow, No-Clean flux, min via hole
size 0.5 mm. No contact problems,
occasionally probes were cleaned because of flux impurities.
I have also heard that some companies design specific void pads on their
pcb`s for testing purposes. those pads are then soldered in normal reflow
process.
Brs, Johannes
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