PCB Libraries Forum Homepage
Forum Home Forum Home > PCB Footprint Expert > Questions & Answers
  New Posts New Posts RSS Feed - Calculator QFP Pad Stack Invalid Number
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Calculator QFP Pad Stack Invalid Number

 Post Reply Post Reply
Author
Message
Stadler_s1 View Drop Down
New User
New User


Joined: 22 Jun 2016
Status: Offline
Points: 2
Post Options Post Options   Thanks (0) Thanks(0)   Quote Stadler_s1 Quote  Post ReplyReply Direct Link To This Post Topic: Calculator QFP Pad Stack Invalid Number
    Posted: 22 Jun 2016 at 5:33am
 
Hello,
 
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.
 
Back to Top
Back to Top
Jeff.M View Drop Down
Admin Group
Admin Group


Joined: 16 May 2012
Location: San Diego
Status: Offline
Points: 477
Post Options Post Options   Thanks (0) Thanks(0)   Quote Jeff.M Quote  Post ReplyReply Direct Link To This Post Posted: 22 Jun 2016 at 8:05am
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! Twitter - 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: 5717
Post Options Post Options   Thanks (0) Thanks(0)   Quote Tom H Quote  Post ReplyReply Direct Link To This Post Posted: 22 Jun 2016 at 8:07am
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! X - LinkedIn
Back to Top
 Post Reply Post Reply

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.219 seconds.