Hi Ben-

Active fluxes wick up stranded wire ahead of the solder wetting. Therefore
there will be flux residue chased up into the strands. If this is
corrosive, the strands will rot up inside the insulation. Usually the
"rotting" is caused by acidic degradation of the stranded wires. The
chemical process apparently uses the halides in a catalytic way, where the
same halide ion can destroy another piece of the wire since it is
automatically regenerated. The process limiter is usually moisture, so if
you can hermetically seal (and get all of the water molecules out) then the
problem is minimized. But most polymers allow water to migrate through.

It seems to me that the plastic shell of the solder sleeve is most likely
not hermetic with respect to water vapor--but even if it were, there's no
way the "seal" around the portions where the wire exits is hermetic.

My question is the reasoning on why solder sleeves aren't forced to use
ROL0, or whether I'm misreading the WHMA's standards.

Wayne T

On Tue, May 26, 2020 at 8:25 AM Gumpert, Ben <[log in to unmask]> wrote:

> Wayne,
>
> I would expect that solder sleeves / cable and harness are at less risk
> than circuit cards for ECM issues that halides would contribute to. How
> well do solder sleeves keep out moisture? What's the potential path for a
> current leakage?
>
> Ben
>
> -----Original Message-----
> From: TechNet <[log in to unmask]> On Behalf Of Wayne Thayer
> Sent: Wednesday, May 20, 2020 8:53 PM
> To: [log in to unmask]
> Subject: EXTERNAL: [TN] Flux in Solder Sleeves
>
> Gentlemen-
>
> From J-STD-001, ROL1 must be cleaned, but then IPC/WHMA-A-620 declares
> that solder sleeves are exempt from cleaning requirements. Why don't the
> extra halides cause problems if they are in a solder sleeve?
>
> TE Connectivity even has ROM1 available, which I guess is OK if it is
> solid wire as opposed to stranded.
>
> Thanks,
>
> Wayne Thayer
>