There was an excellent papers a number of years back from Al Schneider on
Alpha Metals. Showed over 40 of the weak organic acids that could be in
low residue fluxes. Will have to see if I still have it.
*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 Thu, Feb 27, 2020 at 4:25 PM Jenkins, Jeffrey (US) <
[log in to unmask]> wrote:
> Understood 😊 I'm not quite the newbie as I once was, now approaching 25
> years in the electronics field.
>
> Paul, you question regarding the young colleague is similar to the
> situation that I've found myself about 10 years ago. I spent some time
> looking for flux classes due to some "learning opportunities " we had to
> help flesh out my understanding of flux families to avoid further
> "opportunities". I was just able to find literature from vendors and the
> J-Stds.
>
> Vendor info can be helpful, but one has to understand it's coming from
> their business perspective, some of it was out of my depth, and generally
> it all seemed more focused on the metallurgy than the flux. I would have
> liked even a primer class on the different materials, though finding the
> Printed Circuits Handbook did also help. But there are so many pros/cons
> with each type/application/cleaning of each flux that it can be hard for
> someone that doesn't deal with it day in and day out to digest. It really
> is an art and a science.
>
> Around 2014 was when I found the IPC Cleanliness and conformal coat
> conference which helped and I was also introduce to this forum at that
> time.
> But it does appear that flux can often be overlooked until it becomes a
> problem. And most designers and engineers who spec it (or don't spec
> anything at all) are really at the mercy of their vendors.
>
> Jeffrey
>
> -----Original Message-----
> From: Stadem, Richard D <[log in to unmask]>
> Sent: Thursday, February 27, 2020 1:41 PM
> To: TechNet E-Mail Forum <[log in to unmask]>; Jenkins, Jeffrey (US) <
> [log in to unmask]>
> Subject: RE: [External] [TN] No-Clean (ROL0) question....
>
> CAUTION: Email originated from outside of Cubic.
>
>
> You sure are welcome, Jeffrey.
> And never, ever, start off a posting on this forum again with an apology
> for asking a dumb question. There are no dumb questions, and even after 45
> years in this business I (and all of us) are just as much of a "newbie" as
> you are! There is simply too much to learn.
>
> Odin
>
> -----Original Message-----
> From: TechNet <[log in to unmask]> On Behalf Of Jenkins, Jeffrey (US)
> Sent: Thursday, February 27, 2020 3:08 PM
> To: [log in to unmask]
> Subject: Re: [TN] [External] [TN] No-Clean (ROL0) question....
>
> Doug and Richard,
>
> Thank you both very much I do appreciate both of your assistance.
> Something in the back of my mind (probably from IPC Cleanliness
> conferences!) said it’s not the best thing to do. I also went and pulled
> the IPC-CH-65 Paul had mentioned prior and I look forward to reading it.
>
> Best,
>
> -Jeffrey
>
>
> From: Douglas Pauls <[log in to unmask]>
> Sent: Thursday, February 27, 2020 12:55 PM
> To: TechNet E-Mail Forum <[log in to unmask]>; Jenkins, Jeffrey (US) <
> [log in to unmask]>
> Subject: Re: [External] [TN] No-Clean (ROL0) question....
>
> CAUTION: Email originated from outside of Cubic.
>
> Jeffrey,
> I will send you a document that I drew up about 12 years ago, together
> with the late Dr. Bill Kenyon. It talks about no-clean fluxes and why
> someone would choose to clean a no-clean flux. You might find it of
> benefit.
>
> There are also a number of excellent papers by Dr. Mike Bixenman of Kyzen
> on the nature of fluxes under QFNs that more addresses what can happen if
> those low solids residues do not get to the proper temperature.
>
> 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]<
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> >
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> On Thu, Feb 27, 2020 at 2:21 PM Jenkins, Jeffrey (US) <
> [log in to unmask]<mailto:[log in to unmask]>> wrote:
> Fellow TechNetters,
>
> I apologize if this may seem like a newbie question and if so I apologize.
> I've used OR fluxes and RO fluxes and have always had them removed by the
> cleaning process as most of the products that I work on have an expected
> life of 10+ years. We've typically validated the amount of WOA and
> Chlorides and set baselines for those.
>
> Someone posed me a question about cleaning no-cleans. Even though in a
> perfect world a no-clean flux should be 100% inactive after reflow, I'm
> betting that's never perfectly the case. So my view and response was that
> based on the life span and end use environment, my concern would be
> humidity/moisture mixing with the residual material and in the long term
> increasing the risk of dendritic growth and other things. Am I off the
> mark?
>
> Thanks,
>
> Jeffrey A. Jenkins, CID+
> Principal Engineering Designer
> Cubic Mission Solutions
>
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