True but plugging via holes with solder that are 0.5 mm from BGA
attachments is looking for trouble.

> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of David Douthit
> Sent: Friday, October 24, 2003 2:22 PM
> To: [log in to unmask]
> Subject: Re: [TN] Cleaning of via holes under components
>
>
> Brian,
>
> Well said (again!!)
>
> David A. Douthit
> Manager
> LoCan LLC
>
> Brian Ellis wrote:
>
> > I'm a proponent of plugging -- with solder! Not only does
> it stop the
> > contamination problem, but it is electrically and thermally
> desirable,
> > as well. However, it should be done from only one side
> unless you like
> > to see miniature Krakatoas.
> >
> > Brian
> >
> > Paul Baine wrote:
> > > Hello,
> > >
> > > One of our Design Engineers is designing a surface mount PCB
> > > assembly and would prefer not to have the via holes solder mask
> > > tented.  However, he is concerned that, if he does not call up
> > > solder mask tenting on his bare PCB drawing, foreign matter could
> > > find its way into a via hole and, if a component (e.g. an IC) was
> > > mounted over the via hole, the foreign matter might not
> be removed
> > > during the cleaning process.
> > >
> > > Has anyone had experience with this situation?  I would
> appreciate
> > > any help you could give me.
> > >
> > > Thanks very much in advance.
> > >
> > > Paul Baine
> > > Q.A. Manager
> > > C-Tech Ltd.
> > > Cornwall, Ontario, Canada

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