SMD Crystal Naming Convention

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   Hi guys,

the naming of Crystal SMD footprint in LE differs from B and proposed C versions of 7351 doc.

from (proposed) IPC-7351C: 
Crystals (2 leads) ................................XTAL + Body Length X Width X Height + L Lead Length X Width

from LE Pro: 
XTAL1150X490X350D1300L416X6 4N

I guess the "D1300" is a kind of  "toe to toe" nominal dimension.
Where can I find this difference/addition documented?

Cheers, 
/Benn

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BennsPCB Members Profile Send Private Message Find Members Posts Add to Buddy List Advanced User Joined: 30 Jan 2013 Location: Sweden Status: Offline Points: 98	Post Options Post Reply Quote BennsPCB Report Post Thanks(0) Quote Reply Topic: SMD Crystal Naming Convention Posted: 06 Feb 2017 at 4:01am
	Hi guys, the naming of Crystal SMD footprint in LE differs from B and proposed C versions of 7351 doc. from (proposed) IPC-7351C: Crystals (2 leads) ................................XTAL + Body Length X Width X Height + L Lead Length X Width from LE Pro: XTAL1150X490X350D1300L416X6 4N I guess the "D1300" is a kind of "toe to toe" nominal dimension. Where can I find this difference/addition documented? Cheers, /Benn



Tom H Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Joined: 05 Jan 2012 Location: San Diego, CA Status: Offline Points: 5716	Post Options Post Reply Quote Tom H Report Post Thanks(0) Quote Reply Posted: 06 Feb 2017 at 9:08am
	For "Under-Body Outward L" terminal leads, there are 3 dimensions for pad pattern calculation and they are highlighted with a Blue dot and the Note says "Enter 2 of the 3 optional dimensions. Different combinations may result in a slightly different footprint size". D D2 L The Land Pattern Name reflects which 2 of these 3 options you selected. Note: if you enter all 3 dimensions, the resulting land pattern may be too large due to the tolerances of all 3 values.
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BennsPCB Members Profile Send Private Message Find Members Posts Add to Buddy List Advanced User Joined: 30 Jan 2013 Location: Sweden Status: Offline Points: 98	Post Options Post Reply Quote BennsPCB Report Post Thanks(0) Quote Reply Posted: 07 Feb 2017 at 1:15am
	Thanks for the explanation Tom! I do see the point of using this measure in the footprint naming, and perhaps this should be suggested to the IPC guys. Cheers, /Benn

Tom H Members Profile Send Private Message Find Members Posts Add to Buddy List Admin Group Joined: 05 Jan 2012 Location: San Diego, CA Status: Offline Points: 5716	Post Options Post Reply Quote Tom H Report Post Thanks(0) Quote Reply Posted: 07 Feb 2017 at 8:07am
	We did mention to the IPC land pattern committee, but they are trying to introduce a brand new JEDEC naming convention for the next release. PCB Libraries, Inc. will be rejecting the new JEDEC naming proposal as it's 100% different and complex and only one committee member from Mentor Graphics is promoting this major change.
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BennsPCB Members Profile Send Private Message Find Members Posts Add to Buddy List Advanced User Joined: 30 Jan 2013 Location: Sweden Status: Offline Points: 98	Post Options Post Reply Quote BennsPCB Report Post Thanks(0) Quote Reply Posted: 21 Feb 2017 at 12:49pm
	hmm, there's a difference in common sense and Mentor sense. Why make the simple hard, when you can make it impossible.