An excellent set of points.  Thank you Odin.  I especially like #5.  A
corollary would be not to use the reflow oven as a pizza oven.

*Douglas Pauls *| Principal Materials and Process Engr | Advanced
Operations Engineering

*COLLINS AEROSPACE*

400 Collins Road NE, MS 108-101, Cedar Rapids, IA  52498  USA

*Tel:* +1 319 295 2109 | *Mobile: *+1 319 431 3773

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On Wed, Feb 26, 2020 at 10:27 AM Stadem, Richard D <[log in to unmask]>
wrote:

> I think it is critical to train in the basic fundamentals, as applicable.
> Handling after the wash is critical;
>
> 1. Ensure a good blow-off of any remaining water is performed, and explain
> that even after a good wash and rinse, CCAs should never be allowed to sit
> with standing water that can evaporate, leaving behind white residue in the
> form of suspended flux particles, minerals, etc. This is applicable to most
> in-line cleaners, perhaps not for many batch (non-conveyor) cleaners which
> typically perform a drying function within the chamber at the end of the
> final rinse. A good blow-off or drying cycle takes any remaining
> contamination off of most of the CCA with the leftover water.
> 2. Never package wet CCAs directly into closed ESD boxes, bags, or other
> packaging. This ensures creep corrosion, etc., etc,.
> 3. A section on saponifier mix verification, typically done with in-situ
> process analyzers, or whatever method the saponifier manufacturer
> recommends. Information on how the ventilation of the cleaner can cause
> changing mix ratio levels, etc
> 4. Matching of the cleaning process for the flux(s) used. Considerations
> to be given to using batch cleaning with an appropriate saponifier or
> solvent for non-water soluble fluxes, and perhaps an in-line conveyorized
> machine for soluble. Or vice-versa, dependent on the typical product mix.
> 5. Why the cleaning process should ONLY be used for cleaning fluxes and
> "normal" soils, and not for cleaning carburetors, smocks, removing of the
> wrong adhesive (uncured), cleaning of newly-machined shop fixtures/tools
> covered with silicone-bearing cutting grease or oils.
> 6. Prevention of silicone contamination in general. Nothing like an
> operator cleaning heatsink grease as part of a rework procedure to screw up
> your wash process permanently. Just try coating boards after they have been
> washed in a silicone-contaminated cleaner. Such fun!
>
> I will think of more, whether you like it or not, LOL!
>
> dean
>
>
> -----Original Message-----
> From: TechNet <[log in to unmask]> On Behalf Of Douglas Pauls
> Sent: Wednesday, February 26, 2020 6:43 AM
> To: [log in to unmask]
> Subject: [TN] Cleaning Course of Study
>
> Good morning Technetians
>
> OK, so I have been thinking (and we know how dangerous that is) about
> developing a course of study for someone to become a "cleaning expert".
> Something along the lines of starting with a new hire and educating the
> new hires up to my level. Courses would include things like flux chemistry,
> cleaning processes and chemistry, cleanliness measurement methods, SIR
> methods, etc.  What items would you suggest be added to the course of study?
>
> *Douglas Pauls *| Principal Materials and Process Engr | Advanced
> Operations Engineering
>
> *COLLINS AEROSPACE*
>
> 400 Collins Road NE, MS 108-101, Cedar Rapids, IA  52498  USA
>
> *Tel:* +1 319 295 2109 | *Mobile: *+1 319 431 3773
>
> [log in to unmask]
>
> [log in to unmask] for all Export Compliant Items
>