Ron,

We are at the present time measuring the solderability degradation 
of 10 OSP and 9 non-OSP finishes that were provided by many PCB 
manufacturers and chemical suppliers.

This work was part of a larger study carried out here at NPL over the 
last 12 months examining the aging properties of these finishes which 
not only included natural aging but also reflow performance. 

For the natural aging, the PCBS were stored in both laboratory 
and "factory" conditions. At this time, we have tested the PCBs after
12 months using a solderability wetting balance.

We also used a wetting balance, a solder dot test, sequential 
electrochemical reduction analysis (SERA) and a limited yield 
assembly trial for assessment of the reflow properties.

The project had a lot of interesting results including the observation
that many of the OSPs were comparable to the non-OSPs in 
performance. There are obviously a lot more details so just drop me 
a line and we can have a chat....

Best Regards

Lee Hitchens


> 
> 
>      Techneters:
>      
>      Does anyone have definitive data/experience with shelf life for OSP 
>      coated boards?  We presently use 6 months but would like to store for 
>      12 months.  Thanks.
>      
>      Ron Yanuszewski
>      Cabletron Systems, Inc.,
> 
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Lee Hitchens
The National Physical Laboratory
Tel: 0181 943 6583
Fax: 0181 943 6453
email: [log in to unmask]

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