Pad trimming for
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=2652
Printed Date: 22 Nov 2024 at 3:17pm
Topic: Pad trimming for
Posted By: ivanbajic
Subject: Pad trimming for
Date Posted: 15 Jul 2020 at 7:56pm
Hi, We've just stared using PCB Libraries as a reference to generate our footprints. We are using JEDEC standards to reference component outlines. Does anyone know why PCB Libraries does not trim the heel section for a pad when A1 (min)=0.00 mm, i.e.: the component body is sitting flush against the PCB? I'm concerned the Solder Paste on the Heel goal of the pad will slightly lift the component during Surface Mount reflow. For example: I'm using JEDEC MO-193 AB to draw a SOT23-5 footprint. The heel part of the pad is not trimmed. Thanks |
Replies:
Posted By: Tom H
Date Posted: 15 Jul 2020 at 8:22pm
In Preferences > Rules > Minimum Trim Standoff, if you set the value to 0.05 the calculator will automatically trim the pad from under the low profile package when the A1 dimension is less than 0.05.  ------------- Stay connected - follow us! https://twitter.com/PCBLibraries" rel="nofollow - X - http://www.linkedin.com/company/pcb-libraries-inc-/" rel="nofollow - LinkedIn |
Posted By: ivanbajic
Date Posted: 15 Jul 2020 at 9:08pm
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Thanks Tom I had it set to 0.00, so I had about 0.215 mm from the body outline to be end of the pad. Setting the "Min Trim Standoff Height" to 0.05 mm does trim the pads to 0.05 mm.
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Posted By: Tom H
Date Posted: 16 Jul 2020 at 8:02am
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The New V2020 Footprint Expert will default the Minimum Trim Standoff Height (A1) 0.03 mm. But the user can change it to whatever they want. The V2020 Beta can be downloaded at http://www.pcblibraries.com/downloads " rel="nofollow - www.pcblibraries.com/downloads
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