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PCB Library Expert PTH Reference Calculator

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=2510
Printed Date: 07 Oct 2024 at 1:25am


Topic: PCB Library Expert PTH Reference Calculator
Posted By: pholden7
Subject: PCB Library Expert PTH Reference Calculator
Date Posted: 03 Jul 2019 at 5:54am
Is there a version of this that uses "Proportional Padstack" calculations?


Replies:
Posted By: Tom H
Date Posted: 03 Jul 2019 at 7:30am
The PTH Reference calculator and Library Expert Through-hole calculators use what we refer to as incremental pad stack calculation. 

The Hole Size is calculated over the maximum Terminal Lead and the pad stack is 1.5 X the Hole Size. 

A 0.50 mm Hole = 0.75 mm pad size or 0.125 mm annular ring, but the minimum annular ring overrides that. If your minimum annular ring is 0.20 mm then the pad size would be 0.25 mm

A 1.00 mm Hole = 1.50 mm pad size or a 0.25 mm annular ring. 

A 2.00 mm hole = 3.00 mm pad size or a 0.50 mm annular ring. 

Terminal Leads that create large hole sizes probably carry a lot of current or the package is big and bulky and has weight to support. That is the main reason for the larger Annular Ring. To support the package weight and voltage current. Requires additional solder. 



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Posted By: Tom H
Date Posted: 03 Jul 2019 at 7:33am
In Library Expert Enterprise, the through-hole pad stack settings are in - 
Preferences > Terminals > Through-hole > Pad to Hole Ratio & Minimum Annular Ring

In Library Expert Pro, the through-hole pad stack settings are in the Calculator Panel > Terminal tab.



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