Wrong Pad Stack Name?
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=2258
Printed Date: 16 Nov 2024 at 6:01pm
Topic: Wrong Pad Stack Name?
Posted By: dlveazie
Subject: Wrong Pad Stack Name?
Date Posted: 01 Dec 2017 at 8:34am
|
When I use inch dimensions in pad stack calculator, the pad stack name looks like it's getting truncated instead of rounded. Creating pad stack for 0.025" x 0.025" lead says hole size should be 0.041" with 0.061" pad but pad stack name is c61h40.  |
Replies:
Posted By: Jeff.M
Date Posted: 01 Dec 2017 at 9:13pm
|
Pad stack name sizes (and certain footprint sizes) are created in what we call 'centrons'. Without going into a whole lot of detail, a conversion factor is added to a dimension and decimal places are dropped. The hole size in this case is actually 0.409. After conversion and dropping the decimal place it equals 40 not 41 as you would expect if it were simply rounded thus h40. ------------- Stay connected - follow us! https://twitter.com/PCBLibraries" rel="nofollow - Twitter - http://www.linkedin.com/company/pcb-libraries-inc-/" rel="nofollow - LinkedIn |