do you know for sure your CM use DI?  not city water?
On Jul 31, 2014, at 10:38 AM, Nutting, Phil wrote:

> Over the past years we have had relays, optos and pots fail due to  
> corrosion being found inside the parts after post soldering wash.   
> The quick solutions have been to use other manufacturer's parts or  
> install after wash with hand solder "no-clean" cored flux.  One  
> manufacturer said it was because of halides in the flux.  Our  
> primary CM's and our flux contains halides, but we haven't seen as  
> many failures with in-house processed PTH boards as with CM built  
> boards.  Recent pot failures have been explained  by component  
> manufacturers as too much wash pressure or bad flow direction from  
> the wash jets.  Opto failures were similarly diagnosed.
>
> Our in-house process, all PTH, is foam flux with OA flux, wave  
> solder with 63/37 or SC995e followed by a closed loop DI wash with  
> no chemicals.  This has been a great process since 2006 when we  
> switched from a no-clean foam flux, 63/37 wave and terpene/alcohol  
> wash to our listed system above.
>
> We do not dictate flux/wash process to our CMs, but we do specify  
> cleanliness to J-STD-001 C-22 using the 1.56 μgm / cm2 NaCl  
> equivalent contamination value.  Forcing the CM to change fluxes  
> for our product met great resistance and added cost so no change in  
> flux was made.
>
> Our business is high voltage from 30 kV to 240 kV so clean with NO  
> residue is very important.  The DI wash has provided that in-house.
>
> We are using different CMs going forward, but not necessarily for  
> this reason.
>
> Is this a problem unique to us or do other suffer from similar  
> problems?
>
> Phil Nutting  |  HVP Development Engineer   |  Excelitas  
> Technologies Corp
>
> Lab: +1 978.224.4332   |  Office: +1 978.224.4152
> 35 Congress St, Salem, MA  01970 USA
> [log in to unmask]<mailto:[log in to unmask]>
> www.excelitas.com<http://www.excelitas.com/>
>
>
> [Description: Excelitas R_emailsig]
>
>
> Please consider the environment before printing this e-mail.
> ________________________________
> This email message and any attachments are confidential and  
> proprietary to Excelitas Technologies Corp. If you are not the  
> intended recipient of this message, please inform the sender by  
> replying to this email or sending a message to the sender and  
> destroy the message and any attachments. Thank you.
>
>
> ______________________________________________________________________
> This email has been scanned by the Symantec Email Security.cloud  
> service.
> For more information please contact helpdesk at x2960 or  
> [log in to unmask]
> ______________________________________________________________________

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________