Questions & Answers - Assembly vs. Component Outlines

Assembly vs. Component Outlines

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=3368
Printed Date: 06 Oct 2024 at 12:28pm

Topic: Assembly vs. Component Outlines

Posted By: ChrisChris
Subject: Assembly vs. Component Outlines
Date Posted: 07 Apr 2024 at 9:37am

Hello,

I just realized that I've been blindly including both of these in my footprints, both sized to the maximum material condition, but on their own layers (obviously), and I don't really understand why. Can someone please explain the purpose behind having both an Assembly Outline and Component Outline in a footprint? It seems like they are both communicating identical information.

Thank you,

Chris

Replies:

Posted By: Tom H
Date Posted: 07 Apr 2024 at 10:46am

The Assembly Outline can be mapped to Least, Nominal and Maximum package dimensions and indicate Pin 1 Polarity. The Assembly Outline comes with an Assembly Reference Designator on the same layer.

The Component Outline is only mapped to the Nominal package dimensions and does not indicate Pin 1 Polarity. The Component Outline is associated with the Terminal Outlines and does not have a reference designator.

The Component and Assembly Outlines are placed on different layers and their outline widths can be independently assigned.

In Tools > Options, the user can turn on/off any Drafting Outline.

We add features based on customer requests. Someone asked for the Nominal Component Outline with Terminal Outlines. But if you don't see any value with this outline, turn it off.

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Posted By: ChrisChris
Date Posted: 07 Apr 2024 at 10:54am

Ok, thanks Tom!

Posted By: WilliamsimC
Date Posted: 07 May 2024 at 2:42am

The Assembly Outline and the Component Outline are both important parts of designing a PCB, even though they seem similar. They serve different purposes in making sure the PCB is built correctly.

The Assembly Outline is used to create drawings for assembly. These drawings help people putting the components on the PCB to check they're in the right place. The Assembly Outline shows the smallest, average, and largest dimensions of the parts and often points out which way is "Pin 1." It also has a label showing which part it is.

The Component Outline, on the other hand, only shows the average size of the part and doesn't say which way is "Pin 1." It's linked to the Terminal Outlines and doesn't have a label. The Component Outline helps designers see how much space each part takes up on the PCB. This is useful for making sure parts don't overlap and there's enough space between them.

Both outlines are needed because they're used at different times when making a PCB. The Assembly Outline is essential for putting the parts together correctly, while the Component Outline helps in the design phase. It's important to have both to make sure the PCB is made and put together smoothly.