I had some involvement with this Hughes project. It was licensed and marketed by Kester under P/N HF1189 (November, 1989) later to be revised HF1189A (apple juice). HF1189 is still available in pen dispense media. I do recall a tremendous crystalline buildup under the conveyor rails over the solder nozzle which was insoluble in H2O or IPA, but dissolved quite nicely in household ammonia. I assume this was some sort of metallic salt. The boards were left with a haze around the solder joints which also had the same solubility characteristics. I recall the engineer involved along with his red-headed side-kick, but will refrain from mentioning them to protect the innocent.
IMHO, the whole thing was a "publicity stunt" engineered to distract the public eye from other issues looming at the time, but hey, what do I know?! <wink>
Ed Popielarski
Engineering Manager
970 NE 21st Ct.
Oak Harbor, Wa. 98277
Ph: 360-675-1322
Fx: 206-624-0965
Cl: 949-581-6601
https://maps.google.com/maps/myplaces?hl=en&ll=48.315753,-122.643578&spn=0.011188,0.033023&ctz=420&t=m&z=16&iwloc=A
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Mike Fenner
Sent: Wednesday, May 08, 2013 8:13 AM
To: [log in to unmask]
Subject: Re: [TN] Flux classification question
Hello Brian
I waited before answering....
Your brainbox might not be going all the way to peak revs but it's on all cylinders, so you are right - as usual :) I have a less secure memory of a new wonder flux brought out by Hughes [as then was] based on citric which was wonderful in tests but in practice had shortcomings. This would be early/mid 90s? It was taken up under licence by an established flux supplier but quickly dropped. I also remember a critique, I think on this forum so it had to be by you, explaining why it was no good. Something to do with double bonds and insolubility.
So far as Zeva was concerned their machines were a triumph of good German engineering over bad operating principal (they had no choice because of patents), but so far as I recall the only reason for buying their fluxes was because they were part of a package. They were good for engineers to come up with, but were relatively easy for a specialist materials supplier to displace. I should have said:
.... Citric acid ... has a place on the scale, but is not much used in fluxes THESE DAYS.
Best Wishes
Mike
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Brian Ellis
Sent: Wednesday, May 08, 2013 1:12 PM
To: [log in to unmask]
Subject: Re: [TN] Flux classification question
If my aged brainbox is right, ZEVA in Germany made a flux with citric acid activator for their drag soldering machines, going back 40-50 years. It is interesting as being a common tricarboxylic acid, therefore quite a powerful reducing agent. It is also quite a good chelating agent, so can "capture" difficult-to-dissolve heavy metal salts, including both lead and tin ones, so it has a double-whammy effect. It works best as an additive (say 20-30%) to conventional dicarboxylic acid (e.g. adipic), rather than by itself.
Brian
On 08.05.2013 14:57, Mike Fenner wrote:
> HI
> The difficulty of explaining chemistry to non chemists is not to over
> explain it. This just confuses. I usually talk of strong and weak
> acids, weak being natural acids - those found in life usually with
> quite big formulas, and strong or mineral acids which are usually quite simple.
Using
> a scale (logarithmic) to illustrate where on the scale these things go
> and where fluxes would be. Also add in things from daily life which
> people are familiar with Fruit juices, vinegar, cola.
> Citric acid is naturally found in citrus fruits - oranges lemons - has
> a place on the scale, but is not much used in fluxes, it can have wash
> off problems.
>
> Best Wishes
>
>
>
> Mike
>
> -----Original Message-----
> From: Sue Powers-Hartman [mailto:[log in to unmask]]
> Sent: Tuesday, April 30, 2013 6:21 PM
> To: [log in to unmask]
> Subject: RE: [TN] Flux classification question
>
> Mike,
>
> I like what you wrote. While teaching J-Std001 class, I try to define
> the different Fluxes. Would you further define organic and inorganic?
> It is difficult to find what they are made of, tho I have been told
> that organic fluxes are citrus based.
>
> Thanks
>
>
> Sue Powers-Hartman
> Certified IPC Trainer: J-STD-001E, J-STD-001ES, IPC-A 600H,
> IPC-A-610E, IPC/WHMA-A-620A, IPC 7711-7721B, Killdeer Mountain
> Manufacturing
> 233 Rodeo Drive
> Killdeer ND 58640
> 701-764-5651 ext 128
>
>
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Mike Fenner
> Sent: Tuesday, April 30, 2013 10:45 AM
> To: [log in to unmask]
> Subject: Re: [TN] Flux classification question
>
> The term "Resin" describes a group of chemicals which includes natural
> materials such as shellac from beetles and synthetic materials such as
> epoxies. The natural material we are most familiar with in soldering
> is rosin - aka colophony - which is extracted from pine trees in much
> the
same
> way as rubber is tapped. Some of the first soldering fluxes were made
> from rosin which has nearly all the attributes needed for electronic soldering.
> It does not have quite the oxide removal properties to be totally
> satisfactory and so more active chemicals are blended with it, these
> are known as activators. The amount and type added is controlled to
> avoid too much activity which can lead to corrosion. This gave us the
> old style R (pure rosin) RMA (mildly activated and RA (fully activated) designations.
> You can tell the military was involved in these because mildly
> activated rosin would more naturally be abbreviated MAR rather than RMA. :) .
> These old style specs were based on composition, basically they said
> if
you
> use these materials in these proportions and they meet compositional
> tests (e.g. less than a certain amount of activator or leachable acid
> then they were considered safe. In other words pragmatic based on a
> few decades of finding out what worked and what didn't.
> Modern no clean technology requires more than just chemical and
> electrical properties, clear light residues for example and these are
> more easily met by using other resins. If you look at current
> specifications you will see that the no clean classification is the
> same for rosin or resin containing materials. Whether or not a flux
> meets modern specs is not so much
concerned
> with what is in the flux as supplied, but what the residues do after
reflow.
> So the test criteria are surface insulation resistance (SIR) of
> reflowed test pieces and so on. The post solder tests for no cleans
> were based on
how
> RMA fluxes behaved. The RE and RO in flux designations is really now
> for information only and help provide continuity from the previous
> spec regime and flux types to the ones we use now. [Also for those
> still doing legacy work for those requiring MIL spec fluxes.] This
> explanation is somewhat oversimplified for clarity. Hope it helps.
>
> Regards
>
> Mike Fenner
> Bonding Services & Products
> M: +44 [0] 7810 526 317
> T: +44 [0] 1865 522 663
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Graham Collins
> Sent: Tuesday, April 30, 2013 2:13 PM
> To: [log in to unmask]
> Subject: [TN] Flux classification question
>
> Flux gurus, can you tell me the difference between ROLO and RELO fluxes?
>
> (Dewey, I know - the second letter is different, that isn't helpful!)
>
> Is a RELO more active or less? Or does the E mean something else?
>
> --
> regards,
>
> Graham Collins
> Senior Process Engineer
> Sunsel Systems
> (902) 444-7867 ext 211
>
>
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