Well, that is a good point. There are parts of the world where they don't have municipal water supplies that are clean enough to begin with, and the number of radically different cleaning systems/processes vary widely.
We don't all have a "typical" wash process, so the Standard does have to be very generic.
Doug, I am NOT commenting on your particular process, just wanted to point out that the new Standard would have to accommodate a lot of very different scenarios or systems.
dean
-----Original Message-----
From: TechNet <[log in to unmask]> On Behalf Of Douglas Pauls
Sent: Wednesday, February 26, 2020 11:05 AM
To: [log in to unmask]
Subject: Re: [TN] [EXTERNAL] [TN] Cleaning Course of Study
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
>
|
