PCB Libraries Forum : Footprint Name for Parts With Tabs https://www.PCBLibraries.com/forum/ Mon, 13 Apr 2026 07:46:53 +0000 Sun, 21 Oct 2012 13:30:10 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.07 360 https://www.PCBLibraries.com/forum/RSS_post_feed.asp?TID=494 <![CDATA[PCB Libraries Forum]]> https://www.PCBLibraries.com/forum/forum_images/PCBLForumLogo.gif https://www.PCBLibraries.com/forum/ <![CDATA[Footprint Name for Parts With Tabs : The IPC Land Pattern Subcommittee...]]> https://www.PCBLibraries.com/forum/footprint-name-for-parts-with-tabs_topic494_post2055.html#2055 Author: Tom H
Subject: 494
Posted: 21 Oct 2012 at 1:30pm

The IPC Land Pattern Subcommittee hasapproved the use of 3 modifiers at the end of Land Pattern names.

 

Theoriginal IPC-7351 footprint naming convention does not include componenttolerances, thermal pad sizes, BGA Ball sizes or various pin assignments intoaccount. Therefore, the same component with different tolerances can produce adifferent land size and spacing with the same footprint name.

 

Afootprint name of SOP50P710X120-14N can have version A, B, C, D which donot indicate the variances.

 

Thereare 3 component features that affect the footprint name –

1.    ThermalTab Size = SOP50P710X120-14NT300

·        T300 = 3.00 mmSquare Thermal Pad

·        T300X200 = 3.00mm X 2.00 mm Rectangle Thermal Pad

2.    LeadLength Tolerance = SOP50P710X120-14NL50

·        L50 = 0.50 mm Nominal Terminal Length

3.    BallSize = BGA121C50P11X11_600X600X100NB23

·        B23 = 0.23 mm NominalBall Diameter

 

These would be used at the end of the Land Pattern Nameonly if a new Land Pattern is added to the user library with an identical LandPattern Name but different T, L or B.

Example: Create a BGA chart that has a default BallSize for each Pin Pitch.

Pin Pitch

Nominal Ball Diameter

1.50

0.90

1.27

0.75

1.00

0.60

0.80

0.50

0.75

0.45

0.65

0.40

0.50

0.30

0.40

0.25

0.35

0.22

0.30

0.20

 

 

Forcomponent mfr. recommended footprint drop the environment level character afterthe pin qty. - SOP50P710X120-14

]]> Sun, 21 Oct 2012 13:30:10 +0000 https://www.PCBLibraries.com/forum/footprint-name-for-parts-with-tabs_topic494_post2055.html#2055 <![CDATA[Footprint Name for Parts With Tabs : Hi I would like to suggest...]]> https://www.PCBLibraries.com/forum/footprint-name-for-parts-with-tabs_topic494_post1493.html#1493 Author: dipakdesai
Subject: 494
Posted: 08 Aug 2012 at 8:56am

Hi
 
I would like to suggest to add the tab dimension in the footprint name for all parts with tabs example
 
QFN50P1000X1000X90-69N580EP so in this I have added the 5.8mm TAB in the name.
 
Also there are a lot of SOIC packages that have rectangular tab so in these cases it would be better to add 123x456EP. example SOIC127P780X200-14N095x120EP
 
I would be good to add the EP to identify the exposed pad (the TAB) also as shown in the example above.
 
Would it also be better to add a dash in between the N ans the tab dimension e.g SOIC127P780X200-14N-095x120EP
QFN50P1000X1000X90-69N-580EP
 
 
Thanks
Dipak Desai
 
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