same opinion : because the solder joint should not be judged on the toe of
the IC pin, but on the sides and the heel, you should get acceptable
connections.

Marie Magnin

FIRSTEC SA
Rue du Grand Pré 70
CH 1211 Genève 2

Tél.   : +41(0)22 918 36 85
Fax   : +41(0)22 918 36 93
mailto:[log in to unmask]
http://www.firstec.ch


> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]]On Behalf Of Guy Ramsey
> Sent: jeudi, 13. février 2003 01:05
> To: [log in to unmask]
> Subject: Re: [TN] Copper on lead
>
>
> Don't mess with your process 220 is hot enough, (assuming you measured
> the temperature at the leads) and switching to water soluble paste is
> not a trivial change.
>
> Are the leads damaged or is the copper exposed by design?
> Sometimes the
> lead frames are cut and not plated by design. If the exposed copper is
> by design you should still get acceptable connections per
> IPC-A-610C. I
> think Steve had some pictures on his web site.
>
> If you really need better solder fillets than you are
> getting, you might
> consider pre-tinning the leads, then you could probably develop a
> process that safely uses water soluble flux and cleaning.
>
> If the leads are damaged, you should consider returning the parts.
>
>
> > -----Original Message-----
> > From: TechNet [mailto:[log in to unmask]] On Behalf Of Yannick Brisson
> > Sent: Wednesday, February 12, 2003 5:18 PM
> > To: [log in to unmask]
> > Subject: [TN] Copper on lead
> >
> >
> > Hello,
> >
> >   I'm wondering if someone had issue with copper on IC lead.
> > We had a batch of IC where we find that on the side of the
> > lead and at the front about 1/4 of the lead that have copper.
> >  It's seem that the lead have been cut and didn't get plated.
> >  What do you think we shuold do to get a good solder joint.
> > Because right now the solder stop where the copper begin.  We
> > use a no-clean paste.  Should we go to a more aggressive
> > paste? like water solube? shuold we change our profile?, we
> > get a peak of 220celcius.
> >
> > Or anything else you have try?
> >
> >
> > Thanks You
> >
> > Yannick Brisson
> > ============================
> > Technicien SMT
> > Technician SMT
> > M2S Électronique
> > 2855, Rue de Celles
> > Québec, Québec
> > G2C 1K7
> > Téléphone: (418) 842-1312 Ext: 264
> > Télécopie: (418) 842-0123
> > [log in to unmask]
> > ============================
>
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