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Subject:
From:
Wayne Thayer <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Wayne Thayer <[log in to unmask]>
Date:
Wed, 15 Aug 2018 06:22:04 -0700
Content-Type:
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text/plain (72 lines)
Hi Steve-

Thanks for the info. That sounds very reasonable, but it would be nice to
have more analytical data such as
-Which orientation is more susceptible to damage? (seems obvious with the
tabs but I'm not certain on the scores)
-It seems obvious that smaller parts would be less susceptible, so maybe
they can be closer to the edge?

Wayne Thayer

On Tue, Aug 14, 2018 at 11:49 AM, Vargas, Stephen M <
[log in to unmask]> wrote:

> Wayne:
>
>       We recommend keeping larger size ceramic style parts at least .200"
> from the PCB edge where depanelization is required. For V-Scores, we ask
> that a route in the breakaway be added to minimizes the stresses. For
> mouse-bites, we like to see the tabs as far as possible from the edge
> parts.
>
> Regards,
> Steve Vargas
>
> Lockheed Martin RMS-Rotary and Mission Systems
> Polaris Contract Mfg.
> 15 Barnabas Rd
> Marion, MA 02738
> 774-553-6192
> [log in to unmask]
>
>  Please consider the environment before printing this e-mail
>
> -----Original Message-----
> From: TechNet <[log in to unmask]> On Behalf Of Wayne Thayer
> Sent: Tuesday, August 14, 2018 2:36 PM
> To: [log in to unmask]
> Subject: EXTERNAL: Re: [TN] MLCC spacing/orientation to V-score or
> Perforated Tabs
>
> That doesn't give me "warm fuzzies"! I have personally seen pizza wheels
> result in a broken cap 0.125" away (no visual cue, 10% of parts had the
> problem). Leaving a potential reliability issue to each pcb assembly house
> is a real problem for me. And not just me, for all of us who use PCBs. I
> did find a paper from Kemet which touched on the issue, but not in any
> clear, useful guideline kind of way.
>
> Wayne Thayer
>
> On Tue, Aug 14, 2018 at 11:03 AM, John Maxwell <[log in to unmask]> wrote:
>
> > Depend on vendors recommendations for best results
> >
> > Sent from my iPad
> >
> > > On Aug 14, 2018, at 1:24 PM, Wayne Thayer <[log in to unmask]>
> > wrote:
> > >
> > > Hi-
> > >
> > > Is there an IPC standard for distances from components to board edge
> > > for the V-score or perforated tab techniques? I've been able to find
> > > several recommendations from manufacturers, but I couldn't find the
> > > applicable
> > IPC
> > > doc.
> > >
> > > Wayne Thayer
> >
>

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