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Use Extended Footprint Names

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=997
Printed Date: 19 Nov 2024 at 4:20am


Topic: Use Extended Footprint Names
Posted By: lalexman
Subject: Use Extended Footprint Names
Date Posted: 30 Jun 2013 at 6:56am

If you enable "Use Extended Footprint Names" what does that do to the footprint names?

Is it only available for "USR" footprints?


Replies:
Posted By: Tom H
Date Posted: 30 Jun 2013 at 3:06pm

The original IPC-7351 footprint naming convention does not include component "Lead Length" tolerances, Thermal Tab sizes, BGA Ball Diameter or various pin assignments into account. Therefore, the same component with different tolerances can produce a different land size and spacing with the same footprint name.

A footprint name of SOP50P710X120-14N can have version A, B, C, D which do not indicate the variances in Thermal Tab or Lead Length -

  • SOP50P710X120-14AN
  • SOP50P710X120-14BN
  • SOP50P710X120-14CN

There are 3 component features that affect the footprint name

  1. QFN, PQFN, SON, PSON Square Thermal Tab Size = QFN50P500X500X120-14NT300
  2. Rectangle Thermal Tab Shape = QFN50P500X700-20NT300X500
  3. SOP, QFP, SOD, SOT Gull Wing Lead Length Tolerance = SOP50P710X120-14NL50
  4. BGA Ball Size = BGA121C50P11X11_600X600X100NB23
For "component mfr. recommended footprint pattern" drop the environment level character after the pin qty. - SOP50P710X120-14N
 


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