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SODFL & SOTFL

Printed From: PCB Libraries Forum
Category: General
Forum Name: General Discussion
Forum Description: general topics not related to other forums
URL: https://www.PCBLibraries.com/forum/forum_posts.asp?TID=3244
Printed Date: 07 Feb 2025 at 1:26pm


Topic: SODFL & SOTFL
Posted By: mohamedjubair.k
Subject: SODFL & SOTFL
Date Posted: 03 Mar 2023 at 4:13am
Hi Tom,

I read the IPC-7351 document and I did not see solder joint goal table for flat leads [SODFL and SOTFL] components. 

But in library calculator Toe joint value found as 0.20 mm. 

From where did they find this value. Is this 0.20 mm is fine for Toe end.





Replies:
Posted By: Tom H
Date Posted: 03 Mar 2023 at 8:59am
Per IPC J-STD-001 Standard, the Toe value is determined by the Terminal Lead Thickness. 

This is the example of the Gull Wing Terminal Lead form.


 



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Posted By: mohamedjubair.k
Date Posted: 03 Mar 2023 at 6:10pm
Hi Tom,

Thank you for you quick reply. 

Actually I need information about Flat Lead component like attached.


Posted By: Tom H
Date Posted: 04 Mar 2023 at 9:45am
It's the same concept. You take the "Nominal c" dimension (and round up to the nearest 0.05) and that is your Toe goal. 

Anything bigger than that is a waste of PCB real-estate and excess solder. 

The main strength in the solder joint is under the terminal lead. 


 


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Posted By: mohamedjubair.k
Date Posted: 05 Mar 2023 at 8:53am
Thank you so much Tom!


Posted By: MGOS
Date Posted: 23 Oct 2024 at 1:39am
Originally posted by Tom H Tom H wrote:

It's the same concept.


Apologies for hijacking this thread, but I'd rather ask here then create a new thread for the same SODFL package type, if that is OK.

I have some difficulties classifying this type of components as to IPC standard (IPC-A-610J, class 3); mainly, is there a definite type to which they belong and I can check during PCB inspection? For instance, based on figures and specs I could classify as:
  • Flat Gull wing leads -> mentions SOD (not SODFL specifically),
  • Flat lug leads -> J version has added an image of LED (Figure 8-140), whilst pin looks similar to SODFL pin or
  • BTC -> whilst image also look similar to SODFL pins (in regards to Figure 8-161)

I know text has precedence to images that is why I am asking this to finally sort this out for me. Thank you for information.


Posted By: Tom H
Date Posted: 26 Nov 2024 at 11:23am
SOD is Gull Wing leads: 



SODFL is Flat Leads: 



BTC (Bottom Terminal Component) = QFN, SON, PQFN, PSON, BGA, LGA. CGA, etc.



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