Brian,
short and to the point, really a nice one.
But knowing a bit about the special situation, and I think thats also true
for many other small- and mediumsize CMs, there is no or only vague
knowledge regarding the precise requirements for reliability under
(sometimes)not very well known conditions.
Its also often a question of time and resources to perform all necessary
steps to get where you want or need to be.
The first and IMHO most important step is to agree on the criteria one wants
to meet, the rest is business and routine. To master this first "obstacle"
it might be best for many in the same situation to look for external
assistance especially regarding the necessary testing that has to be done
during qualifying.
In Volkmars case I would discuss that topic also with ISIT, an institute
that does a lot of the needed qualification tests and offers consulting for
the electronic industry. I think he knows the contact already.
Greetings from sunny but still cold Hamburg
Wolfgang
> -----Original Message-----
> From: Brian Ellis [mailto:[log in to unmask]]
> Sent: Wednesday, March 27, 2002 12:33 AM
> To: [log in to unmask]
> Subject: Re: [TN] Measuring "No Clean" process quality
>
>
> Volkmar
>
> Manufacturers of fluxes produce and sell a wide range of fluxes which
> are sold as "no-clean". Some contain rosin, others don't. Some contain
> halogenated activators, others don't. Some are very active and are
> consequently easy to solder with, but leave more dangerous residues,
> others don't, but are the devil to solder with. Some you can clean,
> others you cannot.
>
> To answer your questions: you have to select a shortlist of, say, 5
> fluxes which meet your criteria, on paper. You then do
> extensive trials,
> with various parameters (Taguchi is very useful for this, as
> you can cut
> the number of experiments drastically). After having optimised the
> process for each flux, you have to produce some test boards that you
> need to qualify as meeting your requirements for reliability under the
> conditions the boards will be used in (electrochemical migration etc.)
> and for setting up your process for quality control. As a result of
> this, you can select your #1 candidate and #2 to fall back on if there
> is an interruption of supply. No one here can do your
> homework for you,
> I'm afraid.
>
> Brian
>
> Volkmar Huss wrote:
> >
> > Hi TechNetters,
> >
> > we are working on defining our "No Clean" soldering process. The
> > solder-paste and flux manufacturers certify the "No Clean"
> capability of
> >
> > their products to some extend, but what is the definition
> of "No Clean"?
> >
> > And I don't mean the statement, that only inert residues of flux and
> > solder-paste additives remain on the board.
> > Are there any standards that can used as a reference?
> > How do you measure the:
> > "No Clean" capability of solder paste, flux and tubular
> solder with flux
> >
> > core?
> > "No Clean" quality of printed board assemblies?
> > "No Clean" quality of printed board assemblies onto which
> devices have
> > been hand-soldered?
> > and all of this for prototype and series production?
> >
> > I have gleaned some insights from the TechNet archives, but any
> > additional input is very welcome.
> >
> > Best regards
> >
> > Volkmar Hu
> >
> > Engineering Electronic Circuit Boards
> > Aufbau- und Verbindungstechnik
> > _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
> >
> > DRGER ELECTRONICS
> >
> > Draeger Electronics GmbH
> > Moislinger Allee 53-55
> > D-23558 Lbeck
> >
> > Tel: +49-451-882-3998
> > Fax: +49-451-882-4365
> > mailto:[log in to unmask]
> > Website http://www.draeger.com/de/EL
> > _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
> >
> > --
> > Best regards / Mit freundlichen Gren
> >
> > Volkmar Hu
> >
> > Engineering Electronic Circuit Boards
> > Aufbau- und Verbindungstechnik
> > _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
> >
> > DRGER ELECTRONICS
> >
> > Draeger Electronics GmbH
> > Moislinger Allee 53-55
> > D-23558 Lbeck
> >
> > Tel: +49-451-882-3998
> > Fax: +49-451-882-4365
> > mailto:[log in to unmask]
> > Website http://www.draeger.com/de/EL
> > _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
> >
> > M!Lj)K i<uZy oey^<+ x!$
> u{.n+?zwZ(tm),j M! Tf9 _Yh)m {ax f`"
> rzWR cN Tr :-zjh-(Z-^-+ޯ* M!lzw^(tm)'
> r HDygzN0 N qxD(tm) x)zZ?-[azs, צj)m
> ǫ*\ 4r 8 zRy?s*.s,)౫p r :r^<q j>jǬ f"
> > ?+ް^jǯ ȭ y"mY"+fms_ߢ?Yv+bv wf
> ?'-)oe...&jj+?ljƤ*\(;O}M w15==
>
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