Howard, some excellent observations for inclusion. I might shy away a
little from "what is the best way" as that may be a matter of opinion. I
have been told in some cases that MY way is not necessarily the BEST way.
Heresy, if you ask me.....
*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
On Wed, Feb 26, 2020 at 10:34 AM Watson, Howard August <[log in to unmask]>
wrote:
> Hello Doug,
>
> Your email is fortuitous, as we are now experiencing a major cleaning
> issue after a recent change of cleaning solvent. On a more elementary
> level, because that is the level of cleaning knowledge here, it would be
> great to understand the following:
> 1) Related to cleaning chemistry and processes, what is the best process
> to select a new solvent/de-fluxer? Last year, we were finally forced to
> ditch the very much liked Ensolv (nPB/1-Bromopropane). I tried to start a
> campaign to get rid of Ensolv back in 2013 to no avail. The evaluation of
> nPB-free replacements involved testing 4 alternatives, but only qualitative
> data was used for evaluation. Because of the previously mentioned problem,
> starting soon is another round of testing and we will be evaluating
> quantitative data using SIR, FTIR or IC. I also heard we are getting a ROSE
> tester. We have never done any cleanliness testing here in the last 50
> years. Yes, bad habits are going to be hard to break!
> 2) Related to flux chemistry, what else on the CCA are we cleaning, or
> need to clean? Important in my division, because we do NOT have a policy
> that requires gloves or finger cots when handling boards. Worse yet, is
> that it could be 3 months between assembly/de-fluxing and conformal coat,
> with many people handling the boards for testing in that time. Yep, bad
> habits!
> 3) How about dialing in a cleaning process? Is the best way to achieve
> this by performing a factorial design (fractional or full)?
> 4) Is there anything specific to space systems, regarding cleaning
> processes that we need to understand?
>
> Sorry for my biases on this subject, but they are real, albeit probably a
> minority of the TechNet community. Thanks in advance for your work on this
> subject, and when do you think you will have a course of study ready -
> maybe next week?:)
>
> Regards,
>
> Howard A. Watson
> __________________________________________
> Intelligence & Space Research Division, ISR-5, TA-03-2322-504
> Los Alamos National Laboratory
> 30 Bikini Atoll Road
> Los Alamos, NM 87545
> Phone: 505-665-3402
> [log in to unmask]
>
>
>
> -----Original Message-----
> From: TechNet <[log in to unmask]> On Behalf Of Douglas Pauls
> Sent: Wednesday, February 26, 2020 5:43 AM
> To: [log in to unmask]
> Subject: [EXTERNAL] [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
>
|
