1 mm Pitch BGA Courtyard - Nominal Density Level
Printed From: PCB Libraries Forum
Category: Libraries
Forum Name: Footprints / Land Patterns
Forum Description: [General or a CAD specific issues / discussions]
URL: https://www.PCBLibraries.com/forum/forum_posts.asp?TID=1752
Printed Date: 22 Nov 2024 at 1:53am
Topic: 1 mm Pitch BGA Courtyard - Nominal Density Level
Posted By: 5not4
Subject: 1 mm Pitch BGA Courtyard - Nominal Density Level
Date Posted: 24 Aug 2015 at 5:55am
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Hi Tom. Is any history available for the courtyard clearance when using the old LP Calculator? For 1mm pitch BGA's it is creating a 2mm clearance for courtyards and everything that I can find within IPC7351B is stating 1mm is needed for nominal patterns. I have a feeling it is protecting for the component fiducials. I apologize in advance if this is off-limits. LP Calc is still our main tool with the Library Expert as a second opinion/reference tool.
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Replies:
Posted By: Tom H
Date Posted: 24 Aug 2015 at 7:40am
The IPC-7351 standard has been downgraded to a Guideline.  You can use whatever Courtyard Excess you want based on if you ever "Rework" bad BGA's. If you do then you need extra clearance. How much clearance depends on the assembly shop's need for rework space. If you don't rework, the courtyard can be 0.50 mm, but in Library Expert it's a User Preference for every Ball Size. ------------- Stay connected - follow us! https://twitter.com/PCBLibraries" rel="nofollow - X - http://www.linkedin.com/company/pcb-libraries-inc-/" rel="nofollow - LinkedIn |
Posted By: 5not4
Date Posted: 27 Aug 2015 at 5:22am
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Thanks, Tom. We had found one of your previous (MG) Blogs and you had stated this similar thing in reference to rework/no rework clearances.
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