Is there just one screw close to the QFP or is there more than one? Are you screwing the PCB to standoffs or studs? Toby On Jan 14, 2013 11:56 AM, "Jack Olson" <[log in to unmask]> wrote: > 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 > > > > > > > > > > > ______________________________________________________________________ > This email has been scanned by the Symantec Email Security.cloud service. > For more information please contact helpdesk at x2960 or [log in to unmask] > ______________________________________________________________________ > ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________