Arrgh - PCB footprint pad dimensions!

Further to the above, I've just seen a footprint which has *one* dimension between the *centre* of a central pad and the edge of another with *all* the others between the edges!!!

Leon

they do that so you can learn how to use a calculator!

always

few

the

One of my pet peeves as well. So far I haven't screwed up the offset calculations on a board, but it's only a matter of time...

Bob

I always try to print it out 1:1 and lay the part overtop with a new footprint. If there's no samples in hand, that's when problems (this and other kinds) tend to occur.

Best regards, Spehro Pefhany

--
"it\'s the network..."                          "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

Using my CAD software, when creating Patterns like this - I will usually also place the Package Outline information on an Assembly Layer - superimposing it onto the Pad Layout. I will also create little square pads on the Assembly Layer - that way... if something looks 'odd' it will usually jump out at me, and I can investigate further, correcting if necessary.

I had a Pattern recently - for a SIM Card - that dimensioned to the plastic edges... and the Pad edges. That was a challenge. I think mechanicers like to pose interesting challenges when it comes to dimensioning parts.

Regards,

James Jackson Oztronics

always

standard

what

calculations

Hello, everybody. In my opinion it is worth to visit

and try their PCB Libraries Navigator. It is free (demo) for a month period. It helps to design land patterns properly concerning all tolerancies. I would appreciate any opinions about it. Best Regards. Slav.

pads

usually

plastic

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