NO.  not a risk worth taking.  IMHO.  unless you have seal at box  
level (limited exposure to environment).  No clean is not 100%  
inactive, unless you use high heat.  if you use IR or limited peak  
time/temp reflow (to protect sensitive device on PWA), you hardly get  
100%.  IMHO.
my 1.4 cents.
jk
On Feb 27, 2020, at 3:10 PM, Jenkins, Jeffrey (US) wrote:

> Fellow TechNetters,
>
> I apologize if this may seem like a newbie question and if so I  
> apologize.
> I've used OR fluxes and RO fluxes and have always had them removed  
> by the cleaning process as most of the products that I work on have  
> an expected life of 10+ years.  We've typically validated the  
> amount of WOA and Chlorides and set baselines for those.
>
> Someone posed me a question about cleaning no-cleans. Even though  
> in a perfect world a no-clean flux should be 100% inactive after  
> reflow, I'm betting that's never perfectly the case.   So my view  
> and response was that based on the life span and end use  
> environment, my concern would be humidity/moisture mixing with the  
> residual material and in the long term increasing the risk of  
> dendritic growth and other things.  Am I off the mark?
>
> Thanks,
>
> Jeffrey A. Jenkins, CID+
> Principal Engineering Designer
> Cubic Mission Solutions
>
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