HI TOM,

THE MAIN PROBLEM ENCOUNTERED IN A POST REFLOW, HASL RINSE IS IMPROPER ION
CONTAMINANT REMOVAL. YOU DID NOT MENTION IF YOU WERE UTILIZING A
PROPRIETARY, OR OTHERWISE, CLEANER. IF YOUR WATER IS RELATIVELY SOFT YOU
MAY NOT HAVE ANY ADDITIONAL PROBLEMS; PROVIDING YOUR  REFLOW AND
WAVESOLDER ARE PROBLEM-FREE. I.E. PROPER OPERATING AND MAINTAINANCE
PROCEDURES ARE PRACTISED.

IONIC CONTAMINATION CAN  BE DETERMINED BY TESTING. HOWEVER, IF YOUR CURRENT
CUSTOMERS ARE HAPPY, WHY BOTHER.


BEST REGARDS,
 LENNY KURUP TECHNICAL REPRESENTATIVE - CHEMICAL DIV.
EMX ENTERPRISES LTD., MARKHAM, ONTARIO, CANADA. 905-475-8000





 On Tue, 2 Sep 1997, Thomas C Han wrote:

> Hi all,
>
> I am a small contract manufacturer located in San Jose.  We use OA flux
> and water soluble solderpaste for wave-solder and reflow, repectively.  I
> currently use city water for cleaning(approximately 500 gal/day).  I have
> not run into any contamination problems on the PCBs from this process
> yet.   Is there a need to switch to DI?  If so, what are some of the pros
> and cons of using DI water?( cost, effectiveness)  Also, if I do need to
> change, what is the best way to setup a system?  Our current in-line
> cleaner consists of two wash chambers, rinse chamber, and a final rinse
> chamber that can utilize different source of water from the previous.
>
> Any information or suggestions would be greatly appreciated.
>
>
> Tom
>