I was simply surprised that after hearing people talk about boards for so
long, I don't remember anyone sharing any experiences of QFP leads all a
poppin' off from being near a screw.
Regardless:
1) I'm beginning to doubt my memory (old guy)
2) I'm grateful that you can "accept my naivete" and share your quarter
inch. you're a gem.

fading away now...
Jack


On Tue, Jan 15, 2013 at 10:25 AM, Whittaker, Dewey (EHCOE) <
[log in to unmask]> wrote:

>  There are many divine principles, disciplines, mandates and theoretical
> dogmas that have not made their way into IPC-2221, why would you expect
> this question, with all the good previously alluded to variables and
> potential mitigating scenarios, to be covered with a standard keep-out area?
> ****
>
> Since you asked again I'll accept your naiveté on this subject matter and
> state; 0.025 " keep-out clearance from edge of hole to nearest pad geometry.
> ****
>
> Dewey****
>
> ****
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Jack Olson
> Sent: Tuesday, January 15, 2013 8:37 AM
> To: [log in to unmask]
> Subject: Re: [TN] Mounting Hardware to QFP Component Lead
>
> ** **
>
> True, but I can't help but wonder if I'm missing something...****
>
> Of all the issues that the IPC committees have discussed over the last few
> DECADES, why can't I find anything about mounting structures to component
> clearance?****
>
> ** **
>
> hmmm...  dar's gotta be sumpn 'bout dat!****
>
> ** **
>
> thanks anyway,****
>
> Jack****
>
> ** **
>
> .****
>
> On Mon, 14 Jan 2013 19:16:27 +0000, Wayne Thayer <[log in to unmask]>
> wrote:****
>
> ** **
>
> >If it is a new QFP with the pure copper/very high copper leads then I
> wouldn't worry about it.  Those leads are so compliant they can absorb
> amazing amounts of stress.****
>
> >** **
>
> >Wayne Thayer****
>
> >** **
>
> >-----Original Message-----****
>
> >From: TechNet [mailto:[log in to unmask] <[log in to unmask]>] On Behalf Of
> Jack Olson****
>
> >Sent: Monday, January 14, 2013 11:36 AM****
>
> >To: [log in to unmask]****
>
> >Subject: [TN] Mounting Hardware to QFP Component Lead****
>
> >** **
>
> >To the assembly professionals out there:****
>
> >** **
>
> >Have you ever had reliability issues with mounting screws if they are
> near a Quad Flat-Pack? My 144 pin land pattern is pretty close (100mils)
> but we are mounting the board into a very flat structure (no bowing) I
> can't imagine the compression of the board material could affect gull-wing
> style lead connections (maybe BGA?) but I don't know...****
>
> >** **
>
> >thanks,****
>
> >Jack****
>
> >** **
>

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