On Tue, Apr 22, 2014 at 11:31:03AM -0400, Carl Poirier wrote: > So in this case, let's keep what was said before; origin in the middle of > SMT, origin on pin one of THT, which is put in the first quadrant.
There actually is a standard for both pin 1 and orientation. Well, *two* standards :D both IPC (IPC-7351) and IEC (61188-7) have it... the important thing is that the middle is determined by leads, not body. Also, at least here in Italy, many people always use the centroid (even for THT). Finally, there is the EIA-481 (the reel/tube standard) and, anyway, each manufacturer does *whatever he want*. In fact most placement systems use three alignment point: the CAD insertion point, the nozzle/pickup point and the pin 1 point. Pick and place software and the operator make everything match (more or less...). That is unless the operator declare the reel orientation in the wrong way (happened to me:D) My suggestion is: pick a standard and follow it. Most other CADs seems to follow the IPC rules, anyway. For other info search around for 'PCB Design Optimization Starts in the CAD Library', it explains many things quite nicely. > Are there any opinions about schematics using millimeters, which I > mentioned earlier? IIRC the metric schematic proposal was rejected. Don't remember the exact reason. There is a technical issue, however: internally eeschema works in decimils and rounding kills endpoint testing. -- Lorenzo Marcantonio Logos Srl _______________________________________________ Mailing list: https://launchpad.net/~kicad-developers Post to : [email protected] Unsubscribe : https://launchpad.net/~kicad-developers More help : https://help.launchpad.net/ListHelp
