I understand what you are saying, but in this situation people are
recommending moving the QFP144 farther AWAY from the mounting structure.

I can't find any guidance in my IPC documents that would suggest an
appropriate clearance from QFP leads to mounting hardware

Jack


On Mon, Jan 14, 2013 at 10:42 AM, Joyce Koo <[log in to unmask]> wrote:

> It depends.  If your board is flexible somewhat and you do require drop
> test or random vib, and your support points (screw position) is far and in
> between... you might need to worry, not just assembly (flatness is not a
> issue as you say), but reliability.
>
> Joyce Koo
> Materials Researcher - Materials Interconnect Lab
> Research In Motion Limited
> Office: (519) 888-7465 79945
> Mobile: (226) 220-4760
>
> -----Original Message-----
> From: TechNet [mailto:[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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