PCB Libraries Forum Homepage
Forum Home Forum Home > PCB Footprint Expert > Questions & Answers
  New Posts New Posts RSS Feed - Minimum Annular Ring
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Minimum Annular Ring

 Post Reply Post Reply
Author
Message
plinder View Drop Down
Advanced User
Advanced User


Joined: 13 Apr 2012
Location: Vermont
Status: Offline
Points: 141
Post Options Post Options   Thanks (0) Thanks(0)   Quote plinder Quote  Post ReplyReply Direct Link To This Post Topic: Minimum Annular Ring
    Posted: 18 May 2015 at 12:20pm
I set the "Minimum Alowable[sic] Annular Ring" setting to 0.70mm.  However, no through-hole parts that I calculate using the Through Hole calculator honor this setting.  Is this setting for FP generated footprints only?  It would be nice if this applied to all through hole components as some of my parts are approaching my PCB vendor's minimum annular ring spec.
 
Also, it seems like over the years the PCB Libraries through hole proportional pad stacks keep getting smaller (smaller annular rings, hole over lead down to 0.20mm from 0.25mm, etc.) for the same lead size.  Why do these keep changing? 
 
Also, we were previously using IPC-7251 "A" levels.  When published, will IPC-7351C provide a recommended proportional padstack?  If so, will they be comparable to any of the previous "A", "B", or "C" levels (based on your default settings I'm assuming that IPC-7351C proportional padstacks are similar to IPC 7251 Level B settings, though proportional in some calculations instead of fixed)?
Back to Top
Back to Top
Tom H View Drop Down
Admin Group
Admin Group
Avatar

Joined: 05 Jan 2012
Location: San Diego, CA
Status: Offline
Points: 5716
Post Options Post Options   Thanks (0) Thanks(0)   Quote Tom H Quote  Post ReplyReply Direct Link To This Post Posted: 18 May 2015 at 1:18pm
Sorry that we did not link the Minimum Annular Ring to the Calculator. It was a last minute feature addition that was not fully tested.
 
It will be fixed in the next V2015.13 pre-release later today.
 
The typo was fixed in the current .13 pre-release.
 
As far as the changes to the Proportional Pad Stack math goes, we have finally found a good algorithm that works, but the "Minimum Annular Ring" feature overrides the hole to pad size multiplier. The current Multiplier = Hole X 1.50 mm but you can change the 1.50 multiplier to whatever you want. C4hange it to 1.6 or 1.75 and see the difference.
 
Here is the latest PTH Reference Calculator - PCB_Library_Expert_PTH_Reference_Calculator.zip
 
Here is how the PTH Reference Calculator and Library Expert PTH calculations are made.
 
 
Look for the next release of V2015.13 pre-release and everything will be fixed.
 
Stay connected - follow us! X - LinkedIn
Back to Top
Tom H View Drop Down
Admin Group
Admin Group
Avatar

Joined: 05 Jan 2012
Location: San Diego, CA
Status: Offline
Points: 5716
Post Options Post Options   Thanks (0) Thanks(0)   Quote Tom H Quote  Post ReplyReply Direct Link To This Post Posted: 18 May 2015 at 3:17pm
The Minimum Annular Ring is now working in the V2015.13 pre-release - www.pcblibraries.com/downloads
Stay connected - follow us! X - LinkedIn
Back to Top
 Post Reply Post Reply

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.188 seconds.