Hi Hans,
so you keep the saucers flying?
I have allways been wondering about Kester's Solder QPL list: are they
much chosen by the professionals? As such:
- R244, R241, R593, HF-1189SP-1, HF-1189SP
- Formula44, 285, 245, HF-1189CF, 1544-MIL and many more..
They all have a qual ref and a governm. Designation like
R244 = QPL 14256-306-93 = ref M14256LRFP and so on.....
It's all called Kester's MIL-SPEC-BOOK for (water soluble) solder
formulas.
Most of them guarantee SIR uncleaned approx. 10exp11 Ohms and cleaned
10exp12 Ohms, which is well above most requirements.
You may put it this way: are the QPL'ed solders and fluxes what they
promise with regard to Cecilia's questions ? If they are, why bother?
Do you buy and apply QPL'ed solders/fluxes for your saucers? Or are you
a suspicious nature that doesn't accept anything before you have tested
the solders/fluxes yourself?
Kester is not favoured in this mail, was just an example. All other
solder/fluxe makers are supposed to have similar QPL'ed material.
/Ingemar
> Hi Cecilia,
>
> > I need some help on the following topic.
> > Is there any information available on using water soluble flux and
paste
> > in the military/defence industry?
> >
> You can check IPC-HDBK-001 for general information on
soldering.
> ANSI/J-STD-004 covers the requirements for soldering fluxes.
> For the US Military, MIL-F-14256F, which was cancelled, covers
> fluxes.
> ANSI/J-STD-001B covers the requirements for Soldered
Electrical
> Assemblies
> For the US Military, MIL-STD-2000A, and MIL-S-45743E, both
cancelled
> without replacement, covered soldering).
>
> > Does anyone have experience with this kind of flux system for
military
> > applications?
> >
> I haven't been around long but we are required to use what the
> customer specified in the original order which is usually RMA flux for
us.
>
> > How does the residues from water soluble flux affect the reliability
of
> > the product?
> >
> Others with more experience could give you a better picture of
> reliability issues.
> Residues on the board shouldn't be ionic otherwise a short
could
> develop between pins/connectors over time.
> Nonionic residues can be a trap for ionic ones. Our customers
don't
> like to see dirty boards and neither do we.
>
> Alot of Military products I've seen require the boards to be
> conformally coated and so the boards have to be clean very well after
> soldering.
>
> Hans
>
> Air Force Material Command - We keep them flying!
> ~~~~~~~~
> Hans M. Hinners WR-ALC/LYPME Bldg. 640
> Materials Engineer 380 Second
Street,
> Suite 104
> Manufacturing Eng. Sec. Robins AFB GA
31098-1638
> 912-926-1970 (Voice) 468 - 1970 (DSN) 912-926-7974 (Fax)
> [log in to unmask]
>
>
> > Cecilia Alkhagen
> > ******************************************
> > Ericsson Microwave Systems AB
> > Production Engineering Development
> > Bergfotsgatan 2
> > S-431 84 Mölndal
> >
> > Telephone +46 31 747 0000
> > Direct +46 31 747 0288
> > Fax +46 31 747 2635
> >
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