North Sea water is not great for drinking and I would not recommend it for
circuit board cleaning.
Sorry to offer so little help.
Ahne.
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Graham Naisbitt
Sent: 20 February, 2014 00:55
To: [log in to unmask]
Subject: Re: [TN] Cleanliness testing at component level
Hello everybody
Just let you know that I am watching intently. I guess the best approach is
to discuss this at the Las Vegas meetings.
As regards Brian’s Microcontaminometer and the Contaminometer that we now
manufacture to his original quality levels, we can do what Brian mentions
but, the burning question is, what is the ideal condition for components
against which we can make a measure.
If anyone has any questions let me know and I will do what I can to answer
them.
Anyone want some water, we have plenty to get rid of?
Graham
Gen3 Systems
On 19 Feb 2014, at 15:48, Brian Ellis <[log in to unmask]> wrote:
> Joe,
>
> Thanks for your interesting message. It may interest you to know that,
when I developed the Microcontaminometer, I came across a severe problem.
With just a few cubic centimetre of solution in the measuring circuit, how
could I calibrate it? The lowest standard NIST solution is 1
microsiemens-centimetre. If I used this, I would have to measure accurately
quantities in the order of picolitres, which would be an almost impossible
task. It is not possible to use water as the standard solution solvent below
1 microsiemens-centimetre because the conductivity of the salt (potassium
chloride) would be lost in the conductivity of the water. I therefore had to
develop a standard solution with a much lower conductivity and which was
stable. I succeeded with this, down to 0.001 microsiemens centimetre and I
researched the characteristics, such as stability, temperature coefficient,
linearity and so on fairly thoroughly. One major difference is that I used
sodium chloride as the salt, because this was the equivalent used for ionic
contamination testing. As you can imagine, I used an organic solvent as the
major solute.
>
> A few years later, one of my interlocutors informed me that they could no
longer do ionic contamination testing because, following a fire, the company
boss men decreed that no flammable solution could be used or stored in a
plastic container; only metallic containers and pipework were permitted.
This got me thinking and I did a number of experiments, based on the same
solvent as I used in the test solution. This revealed itself, in a 50% mix
with water, as being nonflammable, non-toxic and compatible with the
constructional materials of our instruments with a sensitivity pretty
similar to that of conventional IPA/water mix. Because of its low
volatility, it had less odour than IPA and was consequently more stable,
requiring practically no maintenance of the proportions of the solution.
>
> The big question was whether this solution dissolved flux residues in a
similar way to the conventional IPA/water solution. My tests, which were
rather perfunctory, indicated that it did so for both water-soluble and
rosin-based fluxes. At that time, no-clean fluxes and pastes, as we know
them today, did not exist, so I have no idea as to whether this solution
would be better than, equal to or worse than the conventional solution for
these residues.
>
> This work was done on a mandate by the company that originally acquired
the rights for the Contaminometer, with whom I had a nondisclosure
agreement. As a matter of legal precaution, I don't feel that I can
disclose, at this stage, the composition of the solution. I have no idea
whether the NDA has been passed to Graham Naisbitt and company but I am not
taking the risk or, if it has, is it still valid, as I have signed nothing
with him and the original agreement was dated 1991? Big question marks!
>
> I have vaguely discussed this with Graham on a couple of occasions,
assuming that they may be interested in exploiting it and he is the only
one, other than myself, to know the composition of the solution. However, he
seems reluctant to go ahead with it; I won't discuss this in detail but it
may be a question that the solution costs more than the conventional one. It
has one minor additional disadvantage but several advantages which I think
some may consider more important.
>
> I feel that this subject should be discussed in detail with Graham and
that the work that I did should be in the public domain.
>
> Best regards,
>
> Brian
>
>
>
>
>
> On 19.02.2014 15:37, jrusseau.precisionanalysts.com wrote:
>> Hello Brian,
>>
>> I would certainly be glad to have your valuable input on developing
>> cleanliness methods. Currently, we are considering adapting the
>> existing IPC ion chromatography method for printed boards to include
>> components. We are also considering a completely different method
>> for components. As you are well aware, the no clean fluxes pose some
>> unique challenges in that the old solvent mixture of 75% IPA and 25%
>> DI water really have little ability to bring many of those materials
>> into solution. I have been after our group to look at studying other
>> solvents that might prove better, but many of my colleagues hesitate
>> to abandon the staple mix. They simply want to modify the
concentrations.
>> Alas, I won't bore you with the dilemma's of IPC meetings /
>> discussions, but would relish the opportunity to gain some additional
>> insights that I may be lacking personally and to help drive industry
>> methods into a more modern era.
>>
>> Peace,
>>
>> Joe Russeau
>>
>>
>>
>> ----- Original Message ----- From: "Brian Ellis" <[log in to unmask]>
>> To: <[log in to unmask]>
>> Sent: Wednesday, February 19, 2014 3:32 AM
>> Subject: Re: [TN] Cleanliness testing at component level
>>
>>
>>> In 1983, my now defunct company introduced the Microcontaminometer
>>> MCM-1 which what I claimed was the most sensitive conductivity meter
>>> in the world. The smallest tank was 26 x 26 x 5 mm, to take 1"
>>> wafers, DILs, SOILs, passive components (remember we were still
>>> mostly in the through-hole components era then, except for hybrids).
>>> It could measure a single diode, down to the most sensitive range of
>>> 0-1 µg/cm² eq. NaCl. A better description is on pp 317-9, if you
>>> happen to have my book. An improved MCM-2 with better software on a
>>> PC was launched in 1989. I guess I must have been ahead of my time
>>> by some 30 years or so because measuring component contamination has
>>> been a very silent subject up to now; I can't remember how many MCMs
>>> were sold but you could count the number on two hands, at least
>>> until I ceded the Contaminometer range to a third party in 1991 and
>>> I think they dropped the MCM range. I have no idea if Graham
>>> Naisbitt's company, which now has the rights to the know-how, is
exploiting this niche market.
>>>
>>> Guess Doug has inherited my titles of King of Kaka and Prince of Poo
>>> (actually, I know in Germany I was nicknamed the Reinigung Papst -
>>> Cleaning Pope, slightly more complimentary!). For the anecdote, a
>>> guy in the UK Ministry of Defence called our APL-5 aqueous cleaning
>>> machine the best solderability tester in the world; you just had to
>>> look at the components in the sump to see which ones weren't solderable!
>>>
>>> As for discussing the subject within the IPC, I'm obviously far too
>>> old to participate actively in a committee and I am really well out
>>> of touch with modern components (I retired in 1997), but would be
>>> honoured to be able to help in the editing of any proposals. Modern
>>> technology would make this easy with e-mails and possibly Skype.
>>>
>>> Brian
>>>
>>> On 18.02.2014 22:53, Douglas Pauls wrote:
>>>> That's me, the Emperor of Effluvium, Duke of Dirt, Sultan of
>>>> Schmutz, the Marquis of Mud ...........
>>>>
>>>> As Joe indicated, cleanliness at the component level, or at least
>>>> very small sub-assembly is being examined. Once IPC as an
>>>> organization gets its hands around how do you determine cleanliness
>>>> at that level and give some guidelines on what is desirable, then
>>>> it can go into larger specifications like J-STD-001.
>>>>
>>>> Doug Pauls
>>>>
>>>>
>>>>
>>>> From: "Stadem, Richard D." <[log in to unmask]>
>>>> To: <[log in to unmask]>
>>>> Date: 02/18/2014 02:34 PM
>>>> Subject: Re: [TN] Cleanliness testing at component level
>>>> Sent by: TechNet <[log in to unmask]>
>>>>
>>>>
>>>>
>>>> Yes, the lack of component cleanliness requirements in IPC
>>>> documents is lacking. Are they covered in JEDEC standards? If so, I
>>>> think there should be a reference within the IPC documents,
>>>> especially those standards dealing with cleanliness and
>>>> contamination issues to the next level (contagion). And no, I am
>>>> not going to be a part of that committee, as I am suffering
>>>> sufficient filth unto today to keep me busy thereof. Maybe Doug
>>>> Pauls and Terry Munson? Those guys know dirt like nobody else.
>>>>
>>>> -----Original Message-----
>>>> From: [log in to unmask] [mailto:[log in to unmask]]
>>>> Sent: Tuesday, February 18, 2014 1:56 PM
>>>> To: Stadem, Richard D.; [log in to unmask]
>>>> Subject: RE: Cleanliness testing at component level
>>>>
>>>> Dean,
>>>>
>>>> No, I agree with you completely. I just don't see the specification
>>>> addressing component level. I would like to see the words "component
>>>> level" added so that everyone sees it the way we do.
>>>>
>>>> In my case, the pre-tinned component may be shipped back to me and
>>>> sit in stock for a year before it is assembled onto a PWA which is
>>>> subsequently tested for cleanliness.
>>>>
>>>> Phil
>>>>
>>>> -----Original Message-----
>>>> From: Stadem, Richard D. [mailto:[log in to unmask]]
>>>> Sent: Tuesday, February 18, 2014 9:00 AM
>>>> To: TechNet E-Mail Forum; Bavaro, Phillip @ MWG - TW
>>>> Subject: RE: Cleanliness testing at component level
>>>>
>>>> For me, the difference between components and assemblies is
>>>> becoming so blurred that it is very difficult to determine where
>>>> the spec applies and where it doesn't.
>>>> Can you tell me that a PoP component consisting of 4 stacked
>>>> miniature pwbs that is soldered together using a special flux and
>>>> laser as well as standard solder and flux and touched up and
>>>> cleaned in an in-line cleaner does not require the same treatment
>>>> by the specification as the 36"
>>>> by 24"
>>>> supercomputer CCA that has 24 layers, 36 miles of copper traces,
>>>> weighs 45 lbs when populated with just 24 sockets?
>>>> Why?
>>>>
>>>> -----Original Message-----
>>>> From: TechNet [mailto:[log in to unmask]] On Behalf Of Phil Bavaro
>>>> Sent: Tuesday, February 18, 2014 10:31 AM
>>>> To: [log in to unmask]
>>>> Subject: [TN] Cleanliness testing at component level
>>>>
>>>> I have reviewed the J-STD-001 several times but still have a
>>>> question regarding a subcontractor who performs component level
>>>> soldering operations for Class 3 hardware.
>>>>
>>>>
>>>> If the subcontractor is performing a soldering operation, then
>>>> cleaning is required to remove flux residues (this is not a no
>>>> clean flux situation).
>>>>
>>>> If the subcontractor is cleaning, then cleanliness testing is required.
>>>>
>>>> The J-STD-001 does not really address the component level when it
>>>> comes to the Post Soldering Cleanliness Designator (PSCD).
>>>>
>>>> If a component is having its leads pre-tinned or a BGA being
>>>> re-balled, then is it defaulted to a C-22 PSCD?
>>>>
>>>> My position is yes but I can see where there might be arguments
>>>> against this since the designator codes seem to speak to the
>>>> assembly level and not the component level.
>>>>
>>>> My concern is that there is considerable time lag between when
>>>> component soldering operations are performed relative to the actual
>>>> PWA process which does get checked for cleanliness.
>>>>
>>>> Any input is appreciated.
>>>> ________________________________
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