PCB Libraries Forum : Placement Courtyard Excess

PCB Libraries Forum : Placement Courtyard Excess https://www.PCBLibraries.com/forum/ Thu, 09 Apr 2026 06:11:00 +0000 Fri, 21 Feb 2025 00:27:21 +0000 http://blogs.law.harvard.edu/tech/rss Web Wiz Forums 12.07 360 https://www.PCBLibraries.com/forum/RSS_post_feed.asp?TID=3372 <![CDATA[PCB Libraries Forum]]> https://www.PCBLibraries.com/forum/forum_images/PCBLForumLogo.gif https://www.PCBLibraries.com/forum/ <![CDATA[Placement Courtyard Excess : Thank you Tom for your clarifications...]]> https://www.PCBLibraries.com/forum/placement-courtyard-excess_topic3372_post13804.html#13804 Author: achico
Subject: 3372
Posted: 21 Feb 2025 at 12:27am

Thank you Tom for your clarifications and realistic industry point of view, much appreciated.

Best regards]]> Fri, 21 Feb 2025 00:27:21 +0000 https://www.PCBLibraries.com/forum/placement-courtyard-excess_topic3372_post13804.html#13804 <![CDATA[Placement Courtyard Excess : IPC-7352 does not break down the...]]> https://www.PCBLibraries.com/forum/placement-courtyard-excess_topic3372_post13800.html#13800 Author: Tom H
Subject: 3372
Posted: 20 Feb 2025 at 9:14am

IPC-7352 does not break down the courtyard to Pad and Body separately.

The solder joint goal tables only refer to one courtyard Excess.

Least = 0.10
Nominal = 0.25
Most = 0.50

However, PCB Libraries customers think the Least value of 0.10 is OK, but then they double that for Nominal to 0.20 and then double that for Most to 0.40. Also, Siemens, Cadence and Zuken users turn off all Courtyard Excess values and use the courtyard as a placement boundary outline and they use internal CAD tool spacing rules for part placement.

Both the Nominal and Most Density Levels pass all Class 3 stress tests for shock and vibration, thermal cycling and drop tests. So the Most Density is rarely used in production. But some mil spec contractors still use the Most Density Level, even though the Nominal Density Level performance is equal. But the Courtyard Excess values are user definable so some companies might use the Most pad stack calculation and a Nominal Courtyard Excess.

The main point is that many PCB designers think outside the box and use IPC-7352 as a "Guideline" but don't use it verbatim. They glean some information from IPC but develop internal standards that work best with their assembly process.

Another thing that many people don't understand is that IPC only offers guidelines for pad stacks and courtyard and don't have much information on all the elements that go into a footprint pattern.

Here is an example of some things IPC does not provide guidelines and details for a typical land pattern:

]]> Thu, 20 Feb 2025 09:14:44 +0000 https://www.PCBLibraries.com/forum/placement-courtyard-excess_topic3372_post13800.html#13800 <![CDATA[Placement Courtyard Excess : From IPC-7352 I found this information,...]]> https://www.PCBLibraries.com/forum/placement-courtyard-excess_topic3372_post13799.html#13799 Author: achico
Subject: 3372
Posted: 20 Feb 2025 at 5:34am

From IPC-7352 I found this information, is it correct? It seems to be different as to IPC-7351B referenced.

IPC-7352 Courtyard Distances

Component Type	Density Level	Pad Edge to Courtyard	Component Body to Courtyard
SMD Components	A (Least Density)	0.50 mm	1.00 mm
	B (Nominal Density)	0.25 mm	0.50 mm
	C (Most Density)	0.20 mm	0.25 mm
Through-Hole Components	A (Least Density)	0.75 mm	1.25 mm
	B (Nominal Density)	0.50 mm	1.00 mm
	C (Most Density)	0.25 mm	0.50 mm

]]> Thu, 20 Feb 2025 05:34:27 +0000 https://www.PCBLibraries.com/forum/placement-courtyard-excess_topic3372_post13799.html#13799 <![CDATA[Placement Courtyard Excess : IPC-7351B refers to a 0.25 Courtyard...]]> https://www.PCBLibraries.com/forum/placement-courtyard-excess_topic3372_post13488.html#13488 Author: Tom H
Subject: 3372
Posted: 07 Apr 2024 at 2:54pm

IPC-7351B refers to a 0.25 Courtyard Excess for Nominal Density Level. However, feedback from our customers indicate 0.20 Courtyard Excess works perfect. The Least Density Courtyard Excess is 0.10, Nominal 0.20 and Most is 0.40. There are 2 courtyard settings. One for the package body and one for the pads. The Package Body uses the Maximum package dimension.

Some Enterprise CAD tools turn the courtyard excess off to contour the courtyard to the maximum package dimensions. Then they use the courtyard for Placement Boundary or use the CAD tool rules for footprint to footprint spacing rules.

The manufacturing zone is intended for assembly shops who need more area around the footprint pattern. Your assembly shop needs to communicate this information.

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