QFN land pattern standard?

[TheComet]

Is there a standard for QFN package land patterns? I've noticed some ICs have a pitch of 0.65mm, others have a pitch of 0.5mm and both claim to be a QFN package. This is super confusing because so far my library of land patterns hasn't been making any distinctions between pitches.

0.65mm (Page 15) http://www.yamar.com/datasheet/DS-SIG60.pdf
0.50mm (Page 21) http://cds.linear.com/docs/en/datasheet/37411ff.pdf
0.50mm (Page 38)
http://www.ftdichip.com/Support/Documents/DataSheets/ICs/DS_FT232R.pdf

[DeepOrange]

Perhaps this JEDEC PUBLICATION 95, DESIGN REGISTRATION 4.24 will answer your question:
www.jedec.org/sites/default/files/docs/DRegistration4-24A.pdf (see attached)

[T3sl4co1l]

Whatever it is, doesn't matter all that much -- as long as you follow the drawing, and recommendations, preferably from a PCB assembler that knows what solders best.  IPC-7351B is freely available and a good start for how to dimension most footprints.

Tim

[m98]

I just always use the recommended footprint from the component datasheet. Too many come in non-standardized, vendor specific packages, who sometimes only differ to the standard in one small but important detail.