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3D dot missing

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=3545
Printed Date: 23 Sep 2025 at 5:11pm


Topic: 3D dot missing
Posted By: m.elsayed
Subject: 3D dot missing
Date Posted: 23 Sep 2025 at 1:00pm
1-i need more detail by what means "some 3D missed dot polarity"?
2-what are the packages have this note? 
3- how to correct this dot on 3D?




Replies:
Posted By: Tom H
Date Posted: 23 Sep 2025 at 1:43pm
This package is not a Metric Pin Pitch SOP. The Package Marking has a Dot and no chamfer on the body. 

It is a 50 mil (1.27 mm) pin pitch SOIC. These packages were introduced in the early 1980's when the package had a 45 degree chamfer all along the Pin 1 edge. No Polarity Dot. 

You need to know the difference between Imperial and Metric pin pitch packages. 

We have no plans on changing this polarity marking concept that been around for the past 35 years. 

Metric Pin Pitch SOPs come in these Pin Pitches:
  • 1.00 mm
  • 0.80 mm
  • 0.65 mm
  • 0.50 mm
  • 0.40 mm
The Imperial Pin Pitch SOIC Packages come in these Pin Pitches:
  • 0.05" (1.27 mm)
  • 0.10" (2.54 mm)



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Posted By: m.elsayed
Date Posted: 23 Sep 2025 at 4:02pm
Thanks Tom for your great support and help all time
just if can add more details for packages have this concept other than SOIC and SOP?
also is there any reference document i can read this point on it?


Posted By: m.elsayed
Date Posted: 23 Sep 2025 at 4:41pm
Thanks , Tom
but just if can add more details for packages have this concept other than SOIC and SOP?


Posted By: Tom H
Date Posted: 23 Sep 2025 at 4:46pm
If you see a small outline package with a Chamfer along the entire side of the body where pin 1 is, than you know it's a SOIC. 

If you see a small outline package with a Polarity Dot where pin 1 is, than you know it's a SOP. 

Metric Pin Pitch SOPs come in these Pin Pitches:
  • 1.00 mm
  • 0.80 mm
  • 0.65 mm
  • 0.50 mm
  • 0.40 mm
The Imperial Pin Pitch SOIC Packages come in these Pin Pitches:
  • 0.05" (1.27 mm)
  • 0.10" (2.54 mm)



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Posted By: m.elsayed
Date Posted: 23 Sep 2025 at 4:50pm
great Tom,but i asking same explain for the below packages which i think it have same case, if i'm understand correct




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