Calculator QFP Pad Stack Invalid Number
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=1915
Printed Date: 07 Oct 2024 at 11:28am
Topic: Calculator QFP Pad Stack Invalid Number
Posted By: Stadler_s1
Subject: Calculator QFP Pad Stack Invalid Number
Date Posted: 22 Jun 2016 at 5:33am
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found a little thing here. I Created a 176pin QFP with Datasheet. the Paste Mask Top created a -Size and the Pad Stack Manager says Error.   |
Replies:
Posted By: Jeff.M
Date Posted: 22 Jun 2016 at 8:05am
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There are couple things that might lead to a negative paste mask value The b dimension seems pretty small. Are you sure it's 0.08 mm? I checked a few comparable datasheets and the terminal width is typically 0.17 - 0.27. This small dimension with a small side protrusion goal and a shrink on the solder mask could add up to a negative. ------------- Stay connected - follow us! https://twitter.com/PCBLibraries" rel="nofollow - Twitter - http://www.linkedin.com/company/pcb-libraries-inc-/" rel="nofollow - LinkedIn |
Posted By: Tom H
Date Posted: 22 Jun 2016 at 8:07am
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The only thing I see that's wrong is the "b" lead width has no tolerance and it should, but that would not cause the error but it will cause a bad Land Pattern Footprint. An insufficient pad width. Are you using V2016.07? Here is what I get when I enter your dimensions -  ------------- Stay connected - follow us! https://twitter.com/PCBLibraries" rel="nofollow - X - http://www.linkedin.com/company/pcb-libraries-inc-/" rel="nofollow - LinkedIn |