Werner:

Thanks for your reply. The board will be high-reliability and used in
military. Are there any specifications or documents about this issue?

Thanks again.

R.H.


>From: Werner Engelmaier <[log in to unmask]>
>Reply-To: "TechNet E-Mail Forum." <[log in to unmask]>, [log in to unmask]
>To: [log in to unmask]
>Subject: Re: [TN] Filled via holes
>Date: Thu, 29 Jun 2000 09:17:25 EDT
>
>Hi Ruby,
>Yes, there are some concerns about PTVs partially filled with solder. The
>transition from solder-filled to non-solder-filled produces a stress riser
>in
>the Cu PTV barrel walls. This is of no practical concern for applications
>for
>which the thermal cyclic environment is not severe; for severe
>environments,
>e.g., automotive, military, some satellites, this stress riser can be
>enoughto cause premature failure.
>
>Werner Engelmaier
>Engelmaier Associates, L.C.
>Electronic Packaging, Interconnection and Reliability Consulting
>7 Jasmine Run
>Ormond Beach, FL  32174  USA
>Phone: 904-437-8747, Fax: 904-437-8737
>E-mail: [log in to unmask], Website: www.engelmaier.com
>
>In a message dated 6/28/00 11:19:14, [log in to unmask] writes:
> >Hello all:
> >We try to fully or partially fill the via holes (<0.025" diameter) with
> >solder due to the process. I'm wondering that if there are some concerns
> >(such as fatigue).
> >Any information are very welcome. Thanks a lot!
> >R.H.
>
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