SMD Crystal Naming Convention
Printed From: PCB Libraries Forum
Category: PCB Footprint Expert
Forum Name: Questions & Answers
Forum Description: issues and technical support
URL: https://www.PCBLibraries.com/forum/forum_posts.asp?TID=2080
Printed Date: 19 Nov 2024 at 12:24am
Topic: SMD Crystal Naming Convention
Posted By: BennsPCB
Subject: SMD Crystal Naming Convention
Date Posted: 06 Feb 2017 at 4:01am
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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 |
Replies:
Posted By: Tom H
Date 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".
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. ------------- Stay connected - follow us! https://twitter.com/PCBLibraries" rel="nofollow - X - http://www.linkedin.com/company/pcb-libraries-inc-/" rel="nofollow - LinkedIn |
Posted By: BennsPCB
Date Posted: 07 Feb 2017 at 1:15am
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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 |
Posted By: Tom H
Date Posted: 07 Feb 2017 at 8:07am
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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. ------------- Stay connected - follow us! https://twitter.com/PCBLibraries" rel="nofollow - X - http://www.linkedin.com/company/pcb-libraries-inc-/" rel="nofollow - LinkedIn |
Posted By: BennsPCB
Date Posted: 21 Feb 2017 at 12:49pm
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hmm, there's a difference in common sense and Mentor sense. Why make the simple hard, when you can make it impossible.  |