PCB Libraries Forum : QFN Thermal Tab Paste Mask % https://www.PCBLibraries.com/forum/ Tue, 14 Apr 2026 20:21:48 +0000 Wed, 15 Jan 2020 11:20:14 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.07 360 https://www.PCBLibraries.com/forum/RSS_post_feed.asp?TID=2598 <![CDATA[PCB Libraries Forum]]> https://www.PCBLibraries.com/forum/forum_images/PCBLForumLogo.gif https://www.PCBLibraries.com/forum/ <![CDATA[QFN Thermal Tab Paste Mask % : Library Expert defaults to 50%...]]> https://www.PCBLibraries.com/forum/qfn-thermal-tab-paste-mask_topic2598_post10584.html#10584 Author: Tom H
Subject: 2598
Posted: 15 Jan 2020 at 11:20am

Library Expert defaults to 50% paste mask reduction in the "Rules" tab. 

IPC says the range of Paste Mask Reduction should be 40% - 60%. 

Less than 40% is not enough and greater than 60% is too much. 

]]> Wed, 15 Jan 2020 11:20:14 +0000 https://www.PCBLibraries.com/forum/qfn-thermal-tab-paste-mask_topic2598_post10584.html#10584 <![CDATA[QFN Thermal Tab Paste Mask % : What is a good default value to...]]> https://www.PCBLibraries.com/forum/qfn-thermal-tab-paste-mask_topic2598_post10583.html#10583 Author: jnbrown
Subject: 2598
Posted: 15 Jan 2020 at 11:09am

What is a good default value to use for QFN Thermal Tab Paste Mask %?
I asked our contract manufacturer and they me to use the recommendation on the manufacturers data sheet, however most manufacturers do not specify this.

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