Pat,

A couple of years ago I used an Ultra-Sonic solder for static solder dip.
The solder pot was by Black Stone Ultra-Sonics.  It had a foot peddle you
pushed, which activated the Ultra-Sonics.  It was very effective.  I was
having a major problem with the leads on some PGA substrates.  They were
KOVAR leads and the nickel plating over the KOVAR lead had spots where the
plating was very thin (less than 100u inches, or non-existent).  The iron in
the KOVAR lead was leaching through the nickel plating leaving black spots
which were unsolderable.  Since the substrates were expensive and the
supplier would not accept responsibility for their defective parts we had no
choice, but to try and rework them.  I stripped all the Lead/Tin plate off
the leads.  Soaked the leads in Nickel-Nu.  Replated the leads with Nickel,
and Ultra Sonically solder dipped the leads.    In some cases I was able to
perform the tinning process with no flux.  The rework process was very
successful (75% of the substrates were salvaged), and I believe the high
success rate was partly due to the ultra sonic solder pot.

If you're having an issue with unsolderable surfaces, and the product can
with stand Ultra-Sonics, an Ultra-Sonic solder pot comes in very handy.

Sincerely,
Kathy Palumbo
Manufacturing Engineer
Viking Components, Inc.




> -----Original Message-----
> From: PAT DIAMOND [SMTP:[log in to unmask]]
> Sent: Friday, May 07, 1999 1:23 AM
> To:   [log in to unmask]
> Subject:      [TN] (Fwd) Ultrasonic soldering
>
> Forwarded message:
> From:     Self <SWFN01/PDIAMOND>
> To: [log in to unmask]
> Subject: Ultrasonic soldering
> Reply-to: [log in to unmask]
> Date: Fri, 7 May 1999 08:15:42 EMT+0
>
> Hello all,
>
> I have just been reading an article on Ultrasonic soldering
> which looks interesting, has anyone out there had had any
> experience of this process?
>
> Thanks,
>
> Pat Diamond
> Weston Aerospace
> Pat Diamond
> Senior Manufacturing Engineer
> Weston Aerospace
> Farnborough
> Hampshire
> GU14 7PW
>
> Tel 01252 544433
>
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