BGA Pad Size Does Not Scale With N, M and L?
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=634
Printed Date: 19 Nov 2024 at 7:38am
Topic: BGA Pad Size Does Not Scale With N, M and L?
Posted By: DaveCowl
Subject: BGA Pad Size Does Not Scale With N, M and L?
Date Posted: 25 Oct 2012 at 2:28pm
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I created a land pattern for a Micron memory part BGA and I notice that when I change between N, M and L, there is no change in pad size. It is 0.8mm pitch and 0.45mm ball diameter. Also, as was mentioned yesterday, I am curious as to whether the pad size should be the same as the Solder Mask, or whether the Solder Mask should create the pad opening on a larger copper pad... In any case the following table indicates that the pad size should change with N, M and L - what is best to do here?  |
Replies:
Posted By: Tom H
Date Posted: 25 Oct 2012 at 4:04pm
IPC-7351 only supports 1-Tier for all Grid Array package pad size calculations.  The 3-Tier for the BGA only changes the Silkscreen Line Width, Ref Des Height and Local Fiducial sizes for fine pitch BGA's. |