John, where did you take this screenshot? I am often referring to the document you linked, but I have never seen such a drawing in it. The silkscrees for QFN are on page 61-62, but not the one you attached. I do like it, however. As for the dot, I prefer to ditch it if it's going to be out of the courtyard, as it could potentially collide with some other silkscreen.
On Sat, Sep 20, 2014 at 7:10 PM, John Beard <[email protected]> wrote: > On 20/09/14 16:58, Carl Poirier wrote: > >> Hi folks, >> >> We were unsure how to make the silkscreen for QFN packages. If it's >> done the same as TQFP, it yields, for the pin one indication, a bar so >> short it's going to be difficult to see. ...... I'm unsure if there >> are QFN packages with pins in the reverse order, in which case we >> can't tell from the silkscreen. >> > > I've previously been pointed to PCB Libraries' document: > https://communities.mentor.com/mgcx/servlet/JiveServlet/ > download/28883-8838/PCB%20Design%20Optimization%20Starts%20in%20the%20CAD% > 20Library.pdf > > Their method for QFNs is attached. It's an angle over the corners as > here, but the pin one edge has only one of the lines. The pin without a > line pointing to it is then pin 1. > > The same author also previously used a convention of a chamfered corner > (i.e. under the component and symmetrical), with a pin-1 dot, outside > the IPC courtyard in case the pins are numbered in an anti-clockwise > fashion. > > http://blogs.mentor.com/tom-hausherr/blog/2011/04/06/pcb- > design-perfection-starts-in-the-cad-library-part-15-qfn/ > > I think the dot is useful, even if the silk outline unambiguously > identified pin 1. > > -- > Mailing list: https://launchpad.net/~kicad-lib-committers > Post to : [email protected] > Unsubscribe : https://launchpad.net/~kicad-lib-committers > More help : https://help.launchpad.net/ListHelp > >
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