On Mon, Jun 02, 2014 at 07:34:12PM +0100, John Beard wrote: > button. What client do you use?
mutt. Obviously it doesn't handle it (but could be coerced...) > What is the cost of the yellow layer? It seems to me to show some useful > information (the nominal physical presence of the component, including > the extent of pad overlap) without actually being printed onto the board > and needing silkscreen, ink, etc. Unless you mean cost to the > librarians, in which case I think this c/should be optional (assuming > there was software support in the first place)? The 'cost' of the fabrication layer is simply the full component outline (99% of the times a rectangle) and a corner line for pin 1. But it's not supported anyway. > And maybe we could say the general silk screen border width is 0.2mm, > if this a known constraint of fabricators using silk-screens to do the > silk screen layer? It's not really a constraint, they simply tell you: if it's smaller I don't guarantee a thing (and proceed with a 0.2mm line:D). So small refdes come out as ink blobs > > some CAD system (the mentor ones, I guess, since they somewhat > > invented it) actually do DRC on courtyard to avoid collision and such. > > Physical-collison-detecting DRC sounds handy - I nearly put a resistor > under a QFP on my first KiCad PCB! It happens with very big components too (thing about heatsinks). Don't worry it's a common mistake (however you can usefully nest the gate resistor in the lower space of a D3PAK, right beside the pin...) There is another reason for courtyard excess, namely reworking clearance. BGAs have extra courtyard because the desoldering nozzle is big! -- Lorenzo Marcantonio Logos Srl -- Mailing list: https://launchpad.net/~kicad-lib-committers Post to : kicad-lib-committers@lists.launchpad.net Unsubscribe : https://launchpad.net/~kicad-lib-committers More help : https://help.launchpad.net/ListHelp
