Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Robert Meston

#9930

track/pad layout | 26 August, 1999

Help

I have just received some PCBs with external tracks entering SMD pads at all angles, tangents + 45 degs etc.

Where can I obtain information as to how tracks should enter SMD pads.? I have looked at several IPC books and got some minor info but not enough.

What possible defects could this cause during manufacturing?

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#9931

Re: track/pad layout | 1 September, 1999

| Help | | I have just received some PCBs with external tracks entering SMD pads at all angles, tangents + 45 degs etc. | | Where can I obtain information as to how tracks should enter SMD pads.? I have looked at several IPC books and got some minor info but not enough. | | What possible defects could this cause during manufacturing? | | Bob: Some DFM gurus show traces leaving pads at 45�. You may find some of those types that have guidelines about the angle. I don't know any.

If the angle becomes too sharp (so what's "too" Dave? Dunno) solder mask may peel and solder may slip under and bridge, but ...

I think you have to with your gut for each situation.

Good luck

Dave F

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